Prototype of a Muon Tomography Station with GEM detectors for Detection of Shielded Nuclear Contraband

NASA Astrophysics Data System (ADS)

Staib, Michael; Bhopatkar, Vallary; Bittner, William; Hohlmann, Marcus; Locke, Judson; Twigger, Jessie; Gnanvo, Kondo

2012-03-01

Muon tomography for homeland security aims at detecting well-shielded nuclear contraband in cargo and imaging it in 3D. The technique exploits multiple scattering of atmospheric cosmic ray muons, which is stronger in dense, high-Z materials, e.g. enriched uranium, than in low-Z and medium-Z shielding materials. We have constructed and are operating a compact Muon Tomography Station (MTS) that tracks muons with eight 30 cm x 30 cm Triple Gas Electron Multiplier (GEM) detectors placed on the sides of a cubic-foot imaging volume. A point-of-closest-approach algorithm applied to reconstructed incident and exiting tracks is used to create a tomographic reconstruction of the material within the active volume. We discuss the performance of this MTS prototype including characterization and commissioning of the GEM detectors and the data acquisition systems. We also present experimental tomographic images of small high-Z objects including depleted uranium with and without shielding and discuss the performance of material discrimination using this method.

GEMS X-ray Polarimeter Performance Simulations

NASA Technical Reports Server (NTRS)

Baumgartner, Wayne H.; Strohmayer, Tod; Kallman, Tim; Black, J. Kevin; Hill, Joanne; Swank, Jean

2012-01-01

The Gravity and Extreme Magnetism Small explorer (GEMS) is an X-ray polarization telescope selected as a NASA small explorer satellite mission. The X-ray Polarimeter on GEMS uses a Time Projection Chamber gas proportional counter to measure the polarization of astrophysical X-rays in the 2-10 keV band by sensing the direction of the track of the primary photoelectron excited by the incident X-ray. We have simulated the expected sensitivity of the polarimeter to polarized X-rays. We use the simulation package Penelope to model the physics of the interaction of the initial photoelectron with the detector gas and to determine the distribution of charge deposited in the detector volume. We then model the charge diffusion in the detector,and produce simulated track images. Within the track reconstruction algorithm we apply cuts on the track shape and focus on the initial photoelectron direction in order to maximize the overall sensitivity of the instrument, using this technique we have predicted instrument modulation factors nu(sub 100) for 100% polarized X-rays ranging from 10% to over 60% across the 2-10 keV X-ray band. We also discuss the simulation program used to develop and model some of the algorithms used for triggering, and energy measurement of events in the polarimeter.

Technological aspects of GEM detector design and assembling for soft x-ray application

NASA Astrophysics Data System (ADS)

Kowalska-Strzeciwilk, E.; Chernyshova, M.

2016-09-01

Various types of Micro Pattern Gas Detectors (MPGDs) found applications as tracking detectors in high energy particle physics experiments and as well as imaging detectors, especially for soft X-rays. These detectors offer several advantages like high count rate capability, good spatial and energy resolution, low cost and possibility of constructing large area detectors with very small dead area. Construction, like the triple Gas Electron Multiplier (GEM) detector has become a standard detector, which is widely used for different imaging applications. Some examples of such applications are: monitoring the impurity in plasma, imaging system for mapping of some parameters like pigment distributions using X-ray fluorescence technique[1], proton range radiography system for quality assurance in hadron therapy. Measuring of the Soft X-Ray (SXR) radiation of magnetic fusion plasma is a standard way of accessing valuable information, for example, about particle transport and MHD. The paper is focused on the design of GEM based soft Xray radiation detecting system which is under development. It is dedicated to study soft X-ray emission of plasma radiation with focus on tungsten emission lines energy region. The paper presents the designing, construction and assembling of a prototype of two triple-GEM detectors for soft-X ray application on the WEST device.

Study of a Large Prototype TPC for the ILC using Micro-Pattern Gas Detectors

NASA Astrophysics Data System (ADS)

Münnich, A.; LCTPC Collaboration

2016-04-01

In the last decade, R&D for detectors for the future International Linear Collider (ILC) has been performed by the community. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its tracking system consists of a Si vertex detector, forward tracking disks and a large volume Time Projection Chamber (TPC). Within the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. Its endplate is able to house up to seven identical modules with Micro-Pattern Gas Detectors (MPGD) amplification. Recently, the LP has been equipped with resistive anode Micromegas (MM) or Gas Electron Multiplier (GEM) modules. Both the MM and GEM technologies have been studied with an electron beam up to 6 GeV in a 1 Tesla solenoid magnet. After introducing the current R&D status, recent results will be presented including field distortions, ion gating and spatial resolution as well as future plans of the LCTPC R&D.

Limits of a spatial resolution of the cascaded GEM based detectors

NASA Astrophysics Data System (ADS)

Kudryavtsev, V. N.; Maltsev, T. V.; Shekhtman, L. I.

2017-06-01

Spatial resolution of tracking detectors based on GEM cascades is determined in the simulation and measured. The simulation includes GEANT4 implemented transport of high energy electrons with careful accounting for atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing taking into account diffusion, gas amplification fluctuations, the distribution of signals over readout electrodes, electronics noise and particular algorithm of final coordinate calculation (centre-of-gravity algorithm). The simulation demonstrates that the minimum of the spatial resolution of about 10-20 μm can be achieved with a gas mixture of Ar-CO2 (75%-25%) at a strip pitch in the range from 250 μm to 300 μm. At a larger pitch the resolution quickly degrades reaching 70-100 μm at a pitch of 450-500 μm. The reasons of such behavior are discussed and corresponding hypothesis is tested. Particularly, the effect of electron cloud modification due to a GEM operation is considered using the ANSYS and Garfield++ simulation programs. The detection efficiency and spatial resolution of low-material triple-GEM detectors for the DEUTERON facility at BINP are measured at the extracted beam facility of the VEPP-4M collider. One-coordinate resolution of two detectors for the DEUTERON facility is measured with a 2 GeV electron beam. The determined values of the detectors' spatial resolution is equal to 46.6 ± 0.1 μm and 38.5 ± 0.2 μm for orthogonal tracks in two detectors, respectively.

A Muon Tomography Station with GEM Detectors for Nuclear Threat Detection

NASA Astrophysics Data System (ADS)

Staib, Michael; Gnanvo, Kondo; Grasso, Leonard; Hohlmann, Marcus; Locke, Judson; Costa, Filippo; Martoiu, Sorin; Muller, Hans

2011-10-01

Muon tomography for homeland security aims at detecting well-shielded nuclear contraband in cargo and imaging it in 3D. The technique exploits multiple scattering of atmospheric cosmic ray muons, which is stronger in dense, high-Z nuclear materials, e.g. enriched uranium, than in low-Z and medium-Z shielding materials. We have constructed and operated a compact Muon Tomography Station (MTS) that tracks muons with six to ten 30 cm x 30 cm Triple Gas Electron Multiplier (GEM) detectors placed on the sides of a 27-liter cubic imaging volume. The 2D strip readouts of the GEMs achieve a spatial resolution of ˜130 μm in both dimensions and the station is operated at a muon trigger rate of ˜20 Hz. The 1,536 strips per GEM detector are read out with the first medium-size implementation of the Scalable Readout System (SRS) developed specifically for Micro-Pattern Gas Detectors by the RD51 collaboration at CERN. We discuss the performance of this MTS prototype and present experimental results on tomographic imaging of high-Z objects with and without shielding.

Performance of GEM Detectors in the DarkLight Experiment at LERF

NASA Astrophysics Data System (ADS)

Mohammed Prem Nazeer, Sahara Jesmin; DarkLight Collaboration

2017-01-01

The DarkLight experiment has been proposed to search for a heavy photon A' in the mass range of 10-100 MeV/c2 produced in electron-proton collisions. Phase-I of DarkLight has started to take place in 2016 at the Low Energy Recirculator Facility (LERF) at Jefferson Lab. LERF delivered a 100 MeV electron beam onto a windowless hydrogen gas target. The phase-I detector tracks leptons inside the DarkLight solenoid with a set of Gas Electron Multiplier (GEM) detectors, combined with segmented scintillators for triggering. The GEM telescope consists of four 10 × 10 cm2 triple layer GEM chambers with 2D readout strips, mounted in a slightly angled fixed frame about 12 cm tall. The GEM data are read out with analog pipeline front-end cards (APV-25) each of which can process 128 readout channels. Each GEM chamber has 250 channels for each coordinate axis, read out with two APVs on each side, resulting in 2000 readout channels for the GEM stack, processed by 16 APVs. One Multi Purpose Digitizer (MPD) module is used to read out all of the 16 APV-25 cards. The current run status of DarkLight experiment and the performance of GEMs in the experiment will be discussed. This work has been supported by NSF PHY-1436680 and PHY-1505934.

A cylindrical tripleGEM detector for the BESIII experiment: Measurement of the performance in a magnetic field and project status

NASA Astrophysics Data System (ADS)

Farinelli, R.; BESIII CGEM Group

2017-01-01

A new cylindrical GEM detector is under development to upgrade the tracking system of the BESIII experiment at the IHEP in Beijing. The new detector will replace the current inner drift chamber of the experiment in order to increase significantly the spatial resolution along the beam direction (σ_z ˜ 300 μ m) and to grant the performance of momentum resolution (σ_{p_t}/p_t ˜ 0.5% at 1GeV) and spatial resolution (σ_{xy} ˜ 130 μ m). A cylindrical prototype with the final detector dimensions has been built and the assembly procedure has been successfully validated. Moreover the performance of a 10 × 10 cm ^2 planar GEM has been studied inside a magnetic field by means of a beam test at CERN. The data have been analyzed using two different readout mode: the charge centroid (CC) and the micro time projection chamber ( μ TPC) method.

Performance of a large size triple GEM detector at high particle rate for the CBM Experiment at FAIR

NASA Astrophysics Data System (ADS)

Adak, Rama Prasad; Kumar, Ajit; Dubey, Anand Kumar; Chattopadhyay, Subhasis; Das, Supriya; Raha, Sibaji; Samanta, Subhasis; Saini, Jogender

2017-02-01

In CBM Experiment at FAIR, dimuons will be detected by a Muon Chamber (MUCH) consisting of segmented absorbers of varying widths and tracking chambers sandwiched between the absorber-pairs. In this fixed target heavy-ion collision experiment, operating at highest interaction rate of 10 MHz for Au+Au collision, the inner region of the 1st detector will face a particle rate of 1 MHz/cm2. To operate at such a high particle density, GEM technology based detectors have been selected for the first two stations of MUCH. We have reported earlier the performance of several small-size GEM detector prototypes built at VECC for use in MUCH. In this work, we report on a large GEM prototype tested with proton beam of momentum 2.36 GeV/c at COSY-Jülich Germany. The detector was read out using nXYTER operated in self-triggering mode. An efficiency higher than 96% at ΔVGEM = 375.2 V was achieved. The variation of efficiency with the rate of incoming protons has been found to vary within 2% when tested up to a maximum rate of 2.8 MHz/cm2. The gain was found to be stable at high particle rate with a maximum variation of ∼9%.

A GEM readout with radial zigzag strips and linear charge-sharing response

DOE PAGES

Zhang, Aiwu; Hohlmann, Marcus; Azmoun, Babak; ...

2018-01-10

Here, we study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures aremore » implemented on PCBs and on a flexible foil and are tested using a 10 cm × 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Lastly, angular resolutions of 60–84 μrad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 μm.« less

A GEM readout with radial zigzag strips and linear charge-sharing response

NASA Astrophysics Data System (ADS)

Zhang, Aiwu; Hohlmann, Marcus; Azmoun, Babak; Purschke, Martin L.; Woody, Craig

2018-04-01

We study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures are implemented on PCBs and on a flexible foil and are tested using a 10 cm × 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Angular resolutions of 60-84 μrad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 μm.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cibinetto, G.

Inner Trackers (IT) are key detectors in Particle Physics experiments; excellent spatial resolution, radiation transparency and hardness, and operability under high occupancies are main requirements. We aim to design, build and commission by 2017 a Cylindrical GEM (CGEM) detector candidate to be the new IT of the BESIII spectrometer, hosted on BEPC2 in IHEP, Beijing; BESIII data taking will last until at least 2020. The IT itself will represent an evolution w.r.t. the state of the art of GEM detectors, since the use of new kind of mechanical supports for the GEM foils will reduce the total radiation length ofmore » the detector and improve its tracking performance; an innovative design of the CGEM anode will allow for smaller capacitance and hence for bigger signals. The relatively strong BESIII magnetic field requires a new analogue readout; full custom front-end electronics, including a dedicated ASIC, will be designed and produced for optimal data collection. Prototype Beam Test results showing the measurement of the spatial resolution in a 1 Tesla magnetic field will be presented among with the mechanical design and simulations. (authors)« less

Combined readout of a triple-GEM detector

NASA Astrophysics Data System (ADS)

Antochi, V. C.; Baracchini, E.; Cavoto, G.; Di Marco, E.; Marafini, M.; Mazzitelli, G.; Pinci, D.; Renga, F.; Tomassini, S.; Voena, C.

2018-05-01

Optical readout of GEM based devices by means of high granularity and low noise CMOS sensors allows to obtain very interesting tracking performance. Space resolution of the order of tens of μm were measured on the GEM plane along with an energy resolution of 20%÷30%. The main limitation of CMOS sensors is represented by their poor information about time structure of the event. In this paper, the use of a concurrent light readout by means of a suitable photomultiplier and the acquisition of the electric signal induced on the GEM electrode are exploited to provide the necessary timing informations. The analysis of the PMT waveform allows a 3D reconstruction of each single clusters with a resolution on z of 100 μm. Moreover, from the PMT signals it is possible to obtain a fast reconstruction of the energy released within the detector with a resolution of the order of 25% even in the tens of keV range useful, for example, for triggering purpose.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Aiwu; Hohlmann, Marcus; Azmoun, Babak

Here, we study the position sensitivity of radial zigzag strips intended to read out large GEM detectors for tracking at future experiments. Zigzag strips can cover a readout area with fewer strips than regular straight strips while maintaining good spatial resolution. Consequently, they can reduce the number of required electronic channels and related cost for large-area GEM detector systems. A non-linear relation between incident particle position and hit position measured from charge sharing among zigzag strips was observed in a previous study. We significantly reduce this non-linearity by improving the interleaving of adjacent physical zigzag strips. Zigzag readout structures aremore » implemented on PCBs and on a flexible foil and are tested using a 10 cm × 10 cm triple-GEM detector scanned with a strongly collimated X-ray gun on a 2D motorized stage. Lastly, angular resolutions of 60–84 μrad are achieved with a 1.37 mrad angular strip pitch at a radius of 784 mm. On a linear scale this corresponds to resolutions below 100 μm.« less

Live event reconstruction in an optically read out GEM-based TPC

NASA Astrophysics Data System (ADS)

Brunbauer, F. M.; Galgóczi, G.; Gonzalez Diaz, D.; Oliveri, E.; Resnati, F.; Ropelewski, L.; Streli, C.; Thuiner, P.; van Stenis, M.

2018-04-01

Combining strong signal amplification made possible by Gaseous Electron Multipliers (GEMs) with the high spatial resolution provided by optical readout, highly performing radiation detectors can be realized. An optically read out GEM-based Time Projection Chamber (TPC) is presented. The device permits 3D track reconstruction by combining the 2D projections obtained with a CCD camera with timing information from a photomultiplier tube. Owing to the intuitive 2D representation of the tracks in the images and to automated control, data acquisition and event reconstruction algorithms, the optically read out TPC permits live display of reconstructed tracks in three dimensions. An Ar/CF4 (80/20%) gas mixture was used to maximize scintillation yield in the visible wavelength region matching the quantum efficiency of the camera. The device is integrated in a UHV-grade vessel allowing for precise control of the gas composition and purity. Long term studies in sealed mode operation revealed a minor decrease in the scintillation light intensity.

The current status of the Gas Electron Multiplier (GEM) research at Kasetsart University, Thailand

NASA Astrophysics Data System (ADS)

Kumpiranon, P.; Kulasri, K.; Rittirong, A.; Saenboonruang, K.

2017-06-01

During the past decade, Gas Electron Multiplier (GEM) detectors have been greatly developed and utilized in numbers of applications including advanced nuclear and particle researches, medical imaging, astrophysics, and neutron detection for national security. Our GEM research group at the Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Thailand, realized in its excellent properties/potentials and started extensive researches on GEM detectors. To build a strong foundation on our research group, two 10 cm × 10 cm triple GEM detectors were characterized on their important properties including absolute gains and detection uniformity. Moreover, to widen applications of the GEM detector, our group had modified the GEM detector by introducing either solid or gaseous neutron converters to the detector so that the detector could effectively detect neutrons. These modifications included coating a thin film of 10B and natB to the GEM drift cathode for thermal neutron detection and flowing a gas mixture of He/CO2 (80:20 and 70:30) and C4H10/He/CO2 (7:70:23) for fast neutron detection. Results showed that the modified GEM-based neutron detector could detect both types of neutrons with different relative efficiencies and gains depending on thicknesses and types of neutron converters. This article discusses basic knowledge of the GEM detector, construction and testing procedures, results, and discussion.

Study of spatial resolution of coordinate detectors based on Gas Electron Multipliers

NASA Astrophysics Data System (ADS)

Kudryavtsev, V. N.; Maltsev, T. V.; Shekhtman, L. I.

2017-02-01

Spatial resolution of GEM-based tracking detectors is determined in the simulation and measured in the experiments. The simulation includes GEANT4 implemented transport of high energy electrons with careful accounting of atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing with accounting of diffusion, gas amplification fluctuations, distribution of signals on readout electrodes, electronics noise and particular algorithm of final coordinate calculation (center of gravity). The simulation demonstrates that the minimum of spatial resolution of about 10 μm can be achieved with a gas mixture of Ar -CO2 (75-25 %) at a strips pitch from 250 μm to 300 μm. At a larger pitch the resolution quickly degrades reaching 80-100 μm at a pitch of 460-500 μm. Spatial resolution of low-material triple-GEM detectors for the DEUTERON facility at the VEPP-3 storage ring is measured at the extracted beam facility of the VEPP-4 M collider. One-coordinate resolution of the DEUTERON detector is measured with electron beam of 500 MeV, 1 GeV and 3.5 GeV energies. The determined value of spatial resolution varies in the range from approximately 35 μm to 50 μm for orthogonal tracks in the experiments.

Radiation imaging with optically read out GEM-based detectors

NASA Astrophysics Data System (ADS)

Brunbauer, F. M.; Lupberger, M.; Oliveri, E.; Resnati, F.; Ropelewski, L.; Streli, C.; Thuiner, P.; van Stenis, M.

2018-02-01

Modern imaging sensors allow for high granularity optical readout of radiation detectors such as MicroPattern Gaseous Detectors (MPGDs). Taking advantage of the high signal amplification factors achievable by MPGD technologies such as Gaseous Electron Multipliers (GEMs), highly sensitive detectors can be realised and employing gas mixtures with strong scintillation yield in the visible wavelength regime, optical readout of such detectors can provide high-resolution event representations. Applications from X-ray imaging to fluoroscopy and tomography profit from the good spatial resolution of optical readout and the possibility to obtain images without the need for extensive reconstruction. Sensitivity to low-energy X-rays and energy resolution permit energy resolved imaging and material distinction in X-ray fluorescence measurements. Additionally, the low material budget of gaseous detectors and the possibility to couple scintillation light to imaging sensors via fibres or mirrors makes optically read out GEMs an ideal candidate for beam monitoring detectors in high energy physics as well as radiotherapy. We present applications and achievements of optically read out GEM-based detectors including high spatial resolution imaging and X-ray fluorescence measurements as an alternative readout approach for MPGDs. A detector concept for low intensity applications such as X-ray crystallography, which maximises detection efficiency with a thick conversion region but mitigates parallax-induced broadening is presented and beam monitoring capabilities of optical readout are explored. Augmenting high resolution 2D projections of particle tracks obtained with optical readout with timing information from fast photon detectors or transparent anodes for charge readout, 3D reconstruction of particle trajectories can be performed and permits the realisation of optically read out time projection chambers. Combining readily available high performance imaging sensors with compatible scintillating gases and the strong signal amplification factors achieved by MPGDs makes optical readout an attractive alternative to the common concept of electronic readout of radiation detectors. Outstanding signal-to-noise ratios and robustness against electronic noise allow unprecedented imaging capabilities for various applications in fields ranging from high energy physics to medical instrumentation.

A large ungated TPC with GEM amplification

NASA Astrophysics Data System (ADS)

Berger, M.; Ball, M.; Fabbietti, L.; Ketzer, B.; Arora, R.; Beck, R.; Böhmer, F. V.; Chen, J.-C.; Cusanno, F.; Dørheim, S.; García, F.; Hehner, J.; Herrmann, N.; Höppner, C.; Kaiser, D.; Kis̆, M.; Kleipa, V.; Konorov, I.; Kunkel, J.; Kurz, N.; Leifels, Y.; Müllner, P.; Münzer, R.; Neubert, S.; Rauch, J.; Schmidt, C. J.; Schmitz, R.; Soyk, D.; Vandenbroucke, M.; Voss, B.; Walther, D.; Zmeskal, J.

2017-10-01

A Time Projection Chamber (TPC) is an ideal device for the detection of charged particle tracks in a large volume covering a solid angle of almost 4 π. The high density of hits on a given particle track facilitates the task of pattern recognition in a high-occupancy environment and in addition provides particle identification by measuring the specific energy loss for each track. For these reasons, TPCs with Multiwire Proportional Chamber (MWPC) amplification have been and are widely used in experiments recording heavy-ion collisions. A significant drawback, however, is the large dead time of the order of 1 ms per event generated by the use of a gating grid, which is mandatory to prevent ions created in the amplification region from drifting back into the drift volume, where they would severely distort the drift path of subsequent tracks. For experiments with higher event rates this concept of a conventional TPC operating with a triggered gating grid can therefore not be applied without a significant loss of data. A continuous readout of the signals is the more appropriate way of operation. This, however, constitutes a change of paradigm with considerable challenges to be met concerning the amplification region, the design and bandwidth of the readout electronics, and the data handling. A mandatory prerequisite for such an operation is a sufficiently good suppression of the ion backflow from the avalanche region, which otherwise limits the tracking and particle identification capabilities of such a detector. Gas Electron Multipliers (GEM) are a promising candidate to combine excellent spatial resolution with an intrinsic suppression of ions. In this paper we describe the design, construction and the commissioning of a large TPC with GEM amplification and without gating grid (GEM-TPC). The design requirements have driven innovations in the construction of a light-weight field-cage, a supporting media flange, the GEM amplification and the readout system, which are presented in this paper. We further describe the support infrastructure such as gas, cooling and slow control. Finally, we report on the operation of the GEM-TPC in the FOPI experiment, and describe the calibration procedures which are applied to achieve the design performance of the device.

Gas electron multiplier (GEM) foil test, repair and effective gain calculation

NASA Astrophysics Data System (ADS)

Tahir, Muhammad; Zubair, Muhammad; Khan, Tufail A.; Khan, Ashfaq; Malook, Asad

2018-06-01

The focus of my research is based on the gas electron multiplier (GEM) foil test, repairing and effective gain calculation of GEM detector. During my research work define procedure of GEM foil testing short-circuit, detection short-circuits in the foil. Study different ways to remove the short circuits in the foils. Set and define the GEM foil testing procedures in the open air, and with nitrogen gas. Measure the leakage current of the foil and applying different voltages with specified step size. Define the Quality Control (QC) tests and different components of GEM detectors before assembly. Calculate the effective gain of GEM detectors using 109Cd and 55Fe radioactive source.

Measurement Of Gas Electron Multiplier (GEM) Detector Characteristics

NASA Astrophysics Data System (ADS)

Park, Seongtae; Baldelomar, Edwin; Park, Kwangjune; Sosebee, Mark; White, Andy; Yu, Jaehoon

2011-06-01

The High Energy Physics group of the University of Texas at Arlington has been developing gas electron multiplier detectors to use them as sensitive gap detectors in digital hadron calorimeters for the International Linear Collider, a future high energy particle accelerator. For this purpose, we constructed numerous GEM detectors that employ double GEM layers. In this study, two kinds of prototype GEM detectors were tested; one with 28×28 cm2 active area double GEM structure with a 3 mm drift gap, a 1 mm transfer gap and a 1 mm induction gap and the other with two 3×3 cm2 GEM foils in the amplifier stage with a 5 mm drift gap, a 2 mm transfer gap and a 1 mm induction gap. The detectors' characteristics from exposure to high-energy charged particles and other radiations were measured using cosmic rays and 55Fe radioactive source. From the 55Fe tests, we observed two well separated characteristic X-ray emission peaks and confirmed the detectors' functionality. We also measured chamber gains to be over 6000 at a high voltage of 395 V across each GEM electrode. The responses to cosmic rays show the spectra that fit well to Landau distributions as expected from minimum ionizing particles.

Discriminating cosmic muons and X-rays based on rise time using a GEM detector

NASA Astrophysics Data System (ADS)

Wu, Hui-Yin; Zhao, Sheng-Ying; Wang, Xiao-Dong; Zhang, Xian-Ming; Qi, Hui-Rong; Zhang, Wei; Wu, Ke-Yan; Hu, Bi-Tao; Zhang, Yi

2016-08-01

Gas electron multiplier (GEM) detectors have been used in cosmic muon scattering tomography and neutron imaging over the last decade. In this work, a triple GEM device with an effective readout area of 10 cm × 10 cm is developed, and a method of discriminating between cosmic muons and X-rays based on rise time is tested. The energy resolution of the GEM detector is tested by 55Fe ray source to prove the GEM detector has a good performance. Analysis of the complete signal-cycles allows us to get the rise time and pulse heights. The experiment result indicates that cosmic muons and X-rays can be discriminated with an appropriate rise time threshold. Supported by National Natural Science Foundation of China (11135002, 11275235, 11405077, 11575073)

High granularity tracker based on a Triple-GEM optically read by a CMOS-based camera

NASA Astrophysics Data System (ADS)

Marafini, M.; Patera, V.; Pinci, D.; Sarti, A.; Sciubba, A.; Spiriti, E.

2015-12-01

The detection of photons produced during the avalanche development in gas chambers has been the subject of detailed studies in the past. The great progresses achieved in last years in the performance of micro-pattern gas detectors on one side and of photo-sensors on the other provide the possibility of making high granularity and very sensitive particle trackers. In this paper, the results obtained with a triple-GEM structure read-out by a CMOS based sensor are described. The use of an He/CF4 (60/40) gas mixture and a detailed optimization of the electric fields made possible to obtain a very high GEM light yield. About 80 photons per primary electron were detected by the sensor resulting in a very good capability of tracking both muons from cosmic rays and electrons from natural radioactivity.

Simulation and Digitization of a Gas Electron Multiplier Detector Using Geant4 and an Object-Oriented Digitization Program

NASA Astrophysics Data System (ADS)

McMullen, Timothy; Liyanage, Nilanga; Xiong, Weizhi; Zhao, Zhiwen

2017-01-01

Our research has focused on simulating the response of a Gas Electron Multiplier (GEM) detector using computational methods. GEM detectors provide a cost effective solution for radiation detection in high rate environments. A detailed simulation of GEM detector response to radiation is essential for the successful adaption of these detectors to different applications. Using Geant4 Monte Carlo (GEMC), a wrapper around Geant4 which has been successfully used to simulate the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab, we are developing a simulation of a GEM chamber similar to the detectors currently used in our lab. We are also refining an object-oriented digitization program, which translates energy deposition information from GEMC into electronic readout which resembles the readout from our physical detectors. We have run the simulation with beta particles produced by the simulated decay of a 90Sr source, as well as with a simulated bremsstrahlung spectrum. Comparing the simulation data with real GEM data taken under similar conditions is used to refine the simulation parameters. Comparisons between results from the simulations and results from detector tests will be presented.

Evolution in boron-based GEM detectors for diffraction measurements: from planar to 3D converters

NASA Astrophysics Data System (ADS)

Albani, Giorgia; Perelli Cippo, Enrico; Croci, Gabriele; Muraro, Andrea; Schooneveld, Erik; Scherillo, Antonella; Hall-Wilton, Richard; Kanaki, Kalliopi; Höglund, Carina; Hultman, Lars; Birch, Jens; Claps, Gerardo; Murtas, Fabrizio; Rebai, Marica; Tardocchi, Marco; Gorini, Giuseppe

2016-11-01

The so-called ‘3He-crisis’ has motivated the neutron detector community to undertake an intense R&D programme in order to develop technologies alternative to standard 3He tubes and suitable for neutron detection systems in future spallation sources such as the European spallation source (ESS). Boron-based GEM (gas electron multiplier) detectors are a promising ‘3He-free’ technology for thermal neutron detection in neutron scattering experiments. In this paper the evolution of boron-based GEM detectors from planar to 3D converters with an application in diffraction measurements is presented. The use of 3D converters coupled with GEMs allows for an optimization of the detector performances. Three different detectors were used for diffraction measurements on the INES instrument at the ISIS spallation source. The performances of the GEM-detectors are compared with those of conventional 3He tubes installed on the INES instrument. The conceptual detector with the 3D converter used in this paper reached a count rate per unit area of about 25% relative to the currently installed 3He tube. Its timing resolution is similar and the signal-to-background ratio (S/B) is 2 times lower.

Characterization of a hybrid GEM-Micromegas detector with respect to its application in a continuously read out TPC

NASA Astrophysics Data System (ADS)

Ratza, Viktor; Ball, Markus; Liebtrau, M.; Ketzer, Bernhard

2018-02-01

In the context of the upgrade of the LHC during the second long shutdown the interaction rate of the ALICE experiment will be increased up to 50 kHz for Pb-Pb collisions. As a consequence, a continuous read-out of the Time Projection Chamber (TPC) will be required. To keep the space-charge distortions at a manageable size, the ion backflow of the charge amplification system has to be significantly reduced. At the same time an excellent detector performance and stability of the system has to be maintained. A solution with four Gaseous Electron Multipliers (GEMs) has been adopted as baseline solution for the upgraded chambers. As an alternative approach a hybrid GEM-Micromegas detector consisting of one Micromegas (MM) and two GEMs has been investigated. The recent results of the study of the hybrid GEM-Micromegas detector will be presented and compared to measurements with four GEM foils.

Evaluation of a GEM and CAT-based detector for radiation therapy beam monitoring

NASA Astrophysics Data System (ADS)

Brahme, A.; Danielsson, M.; Iacobaeus, C.; Ostling, J.; Peskov, V.; Wallmark, M.

2000-11-01

We are developing a radiation therapy beam monitor for the Karolinska Institute. This monitor will consist of two consecutive detectors confined in one gas chamber: a "keV-photon detector", which will allow diagnostic quality visualization of the patient, and a "MeV-photon detector", that will measure the absolute intensity of the therapy beam and its position with respect to the patient. Both detectors are based on highly radiation resistant gas and solid photon to electron converters, combined with GEMs and a CAT as amplification structures. We have performed systematic studies of the high-rate characteristics of the GEM and the CAT, as well as tested the electron transfer through these electron multipliers and various types of converters. The tests show that the GEM and the CAT satisfy all requirements for the beam monitoring system. As a result of these studies we successfully developed and tested a full section of the beam monitor equipped with a MeV-photon converter placed between the GEM and the CAT.

A new design using GEM-based technology for the CMS experiment

NASA Astrophysics Data System (ADS)

Ressegotti, M.

2017-07-01

The muon system of the Compact Muon Solenoid (CMS) experiment at the LHC is currently not instrumented for pseudorapidity higher than |η|> 2.4. The main challenges to the installation of a detector in that position are the high particle flux to be sustained, a high level of radiation, and the ability to accomodate a multilevel detector into the small available space (less than 30 cm). A new back-to-back configuration of a Gas Electron Multiplier (GEM) detector is presented with the aim of developing a compact, multi-layer GEM detector. It is composed of two independent stacked triple-GEM detectors, positioned with the anodes toward the outside and sharing the same cathode plane, which is located at the center of the chamber, to reduce the total detector's thickness. A first prototype has been produced and tested with an X-Ray source and muon beam. First results on its performance are presented.

Python based integration of GEM detector electronics with JET data acquisition system

NASA Astrophysics Data System (ADS)

Zabołotny, Wojciech M.; Byszuk, Adrian; Chernyshova, Maryna; Cieszewski, Radosław; Czarski, Tomasz; Dalley, Simon; Hogben, Colin; Jakubowska, Katarzyna L.; Kasprowicz, Grzegorz; Poźniak, Krzysztof; Rzadkiewicz, Jacek; Scholz, Marek; Shumack, Amy

2014-11-01

This paper presents the system integrating the dedicated measurement and control electronic systems for Gas Electron Multiplier (GEM) detectors with the Control and Data Acquisition system (CODAS) in the JET facility in Culham, England. The presented system performs the high level procedures necessary to calibrate the GEM detector and to protect it against possible malfunctions or dangerous changes in operating conditions. The system also allows control of the GEM detectors from CODAS, setting of their parameters, checking their state, starting the plasma measurement and to reading the results. The system has been implemented using the Python language, using the advanced libraries for implementation of network communication protocols, for object based hardware management and for data processing.

GEM-based TPC with CCD imaging for directional dark matter detection

NASA Astrophysics Data System (ADS)

Phan, N. S.; Lauer, R. J.; Lee, E. R.; Loomba, D.; Matthews, J. A. J.; Miller, E. H.

2016-11-01

The most mature directional dark matter experiments at present all utilize low-pressure gas Time Projection Chamber (TPC) technologies. We discuss some of the challenges for this technology, for which balancing the goal of achieving the best sensitivity with that of cost effective scale-up requires optimization over a large parameter space. Critical for this are the precision measurements of the fundamental properties of both electron and nuclear recoil tracks down to the lowest detectable energies. Such measurements are necessary to provide a benchmark for background discrimination and directional sensitivity that could be used for future optimization studies for directional dark matter experiments. In this paper we describe a small, high resolution, high signal-to-noise GEM-based TPC with a 2D CCD readout designed for this goal. The performance of the detector was characterized using alpha particles, X-rays, gamma-rays, and neutrons, enabling detailed measurements of electron and nuclear recoil tracks. Stable effective gas gains of greater than 1 × 105 were obtained in 100 Torr of pure CF4 by a cascade of three standard CERN GEMs each with a 140 μm pitch. The high signal-to-noise and sub-millimeter spatial resolution of the GEM amplification and CCD readout, together with low diffusion, allow for excellent background discrimination between electron and nuclear recoils down below ∼10 keVee (∼23 keVr fluorine recoil). Even lower thresholds, necessary for the detection of low mass WIMPs for example, might be achieved by lowering the pressure and utilizing full 3D track reconstruction. These and other paths for improvements are discussed, as are possible fundamental limitations imposed by the physics of energy loss.

Performance verification of the Gravity and Extreme Magnetism Small explorer (GEMS) x-ray polarimeter

NASA Astrophysics Data System (ADS)

Enoto, Teruaki; Black, J. Kevin; Kitaguchi, Takao; Hayato, Asami; Hill, Joanne E.; Jahoda, Keith; Tamagawa, Toru; Kaneko, Kenta; Takeuchi, Yoko; Yoshikawa, Akifumi; Marlowe, Hannah; Griffiths, Scott; Kaaret, Philip E.; Kenward, David; Khalid, Syed

2014-07-01

Polarimetry is a powerful tool for astrophysical observations that has yet to be exploited in the X-ray band. For satellite-borne and sounding rocket experiments, we have developed a photoelectric gas polarimeter to measure X-ray polarization in the 2-10 keV range utilizing a time projection chamber (TPC) and advanced micro-pattern gas electron multiplier (GEM) techniques. We carried out performance verification of a flight equivalent unit (1/4 model) which was planned to be launched on the NASA Gravity and Extreme Magnetism Small Explorer (GEMS) satellite. The test was performed at Brookhaven National Laboratory, National Synchrotron Light Source (NSLS) facility in April 2013. The polarimeter was irradiated with linearly-polarized monochromatic X-rays between 2.3 and 10.0 keV and scanned with a collimated beam at 5 different detector positions. After a systematic investigation of the detector response, a modulation factor >=35% above 4 keV was obtained with the expected polarization angle. At energies below 4 keV where the photoelectron track becomes short, diffusion in the region between the GEM and readout strips leaves an asymmetric photoelectron image. A correction method retrieves an expected modulation angle, and the expected modulation factor, ~20% at 2.7 keV. Folding the measured values of modulation through an instrument model gives sensitivity, parameterized by minimum detectable polarization (MDP), nearly identical to that assumed at the preliminary design review (PDR).

Design of T-GEM detectors for X-ray diagnostics on JET

NASA Astrophysics Data System (ADS)

Rzadkiewicz, J.; Dominik, W.; Scholz, M.; Chernyshova, M.; Czarski, T.; Czyrkowski, H.; Dabrowski, R.; Jakubowska, K.; Karpinski, L.; Kasprowicz, G.; Kierzkowski, K.; Pozniak, K.; Salapa, Z.; Zabolotny, W.; Blanchard, P.; Tyrrell, S.; Zastrow, K.-D.; JET EFDA Contributors

2013-08-01

Upgraded high-resolution X-ray diagnostics on JET is expected to monitor the plasma radiation emitted by W46+ and Ni26+ ions at 2.4 keV and 7.8 keV photon energies, respectively. Both X-ray lines will be monitored by new generation energy-resolved micropattern gas detectors with 1-D position reconstruction capability. The detection structure is based on triple GEM (T-GEM) amplification structure followed by the strip readout electrode. This article presents a design of new detectors and prototype detector tests.

Construction of the TH-GEM detector components for metrology of low energy ionizing radiation

NASA Astrophysics Data System (ADS)

Silva, N. F.; Silva, T. F.; Castro, M. C.; Natal da Luz, H.; Caldas, L. V. E.

2018-03-01

The Gas Electron Multiplier (GEM) detector was originally proposed as a position sensitive detector to determine trajectories of particles prevenient from high-energy collisions. In order to study the potential of TH-GEM type detectors in dosimetric applications for low energy X-rays, specifically for the mammography standard qualities, it was proposed to construct a prototype with characteristics suitable for such use. In this work the general, structural and material parameters applicable to the necessary conditions were defined, establishing the process of construction of the components of a prototype.

FPGA-based GEM detector signal acquisition for SXR spectroscopy system

NASA Astrophysics Data System (ADS)

Wojenski, A.; Pozniak, K. T.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Zabolotny, W.; Chernyshova, M.; Czarski, T.; Malinowski, K.

2016-11-01

The presented work is related to the Gas Electron Multiplier (GEM) detector soft X-ray spectroscopy system for tokamak applications. The used GEM detector has one-dimensional, 128 channel readout structure. The channels are connected to the radiation-hard electronics with configurable analog stage and fast ADCs, supporting speeds of 125 MSPS for each channel. The digitalized data is sent directly to the FPGAs using fast serial links. The preprocessing algorithms are implemented in the FPGAs, with the data buffering made in the on-board 2Gb DDR3 memory chips. After the algorithmic stage, the data is sent to the Intel Xeon-based PC for further postprocessing using PCI-Express link Gen 2. For connection of multiple FPGAs, PCI-Express switch 8-to-1 was designed. The whole system can support up to 2048 analog channels. The scope of the work is an FPGA-based implementation of the recorder of the raw signal from GEM detector. Since the system will work in a very challenging environment (neutron radiation, intense electro-magnetic fields), the registered signals from the GEM detector can be corrupted. In the case of the very intense hot plasma radiation (e.g. laser generated plasma), the registered signals can overlap. Therefore, it is valuable to register the raw signals from the GEM detector with high number of events during soft X-ray radiation. The signal analysis will have the direct impact on the implementation of photon energy computation algorithms. As the result, the system will produce energy spectra and topological distribution of soft X-ray radiation. The advanced software was developed in order to perform complex system startup and monitoring of hardware units. Using the array of two one-dimensional GEM detectors it will be possible to perform tomographic reconstruction of plasma impurities radiation in the SXR region.

Geopotential models of the Earth from satellite tracking, altimeter and surface gravity observations: GEM-T3 and GEM-T3S

NASA Technical Reports Server (NTRS)

Lerch, F. J.; Nerem, R. S.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Klosko, S. M.; Patel, G. B.; Williamson, R. G.; Chinn, D. S.; Chan, J. C.

1992-01-01

Improved models of the Earth's gravitational field have been developed from conventional tracking data and from a combination of satellite tracking, satellite altimeter and surface gravimetric data. This combination model represents a significant improvement in the modeling of the gravity field at half-wavelengths of 300 km and longer. Both models are complete to degree and order 50. The Goddard Earth Model-T3 (GEM-T3) provides more accurate computation of satellite orbital effects as well as giving superior geoidal representation from that achieved in any previous GEM. A description of the models, their development and an assessment of their accuracy is presented. The GEM-T3 model used altimeter data from previous satellite missions in estimating the orbits, geoid, and dynamic height fields. Other satellite tracking data are largely the same as was used to develop GEM-T2, but contain certain important improvements in data treatment and expanded laser tracking coverage. Over 1300 arcs of tracking data from 31 different satellites have been used in the solution. Reliable estimates of the model uncertainties via error calibration and optimal data weighting techniques are discussed.

FPGA based charge fast histogramming for GEM detector

NASA Astrophysics Data System (ADS)

Poźniak, Krzysztof T.; Byszuk, A.; Chernyshova, M.; Cieszewski, R.; Czarski, T.; Dominik, W.; Jakubowska, K.; Kasprowicz, G.; Rzadkiewicz, J.; Scholz, M.; Zabolotny, W.

2013-10-01

This article presents a fast charge histogramming method for the position sensitive X-ray GEM detector. The energy resolved measurements are carried out simultaneously for 256 channels of the GEM detector. The whole process of histogramming is performed in 21 FPGA chips (Spartan-6 series from Xilinx) . The results of the histogramming process are stored in an external DDR3 memory. The structure of an electronic measuring equipment and a firmware functionality implemented in the FPGAs is described. Examples of test measurements are presented.

Technical design report for the overline{P}ANDA (Anti Proton Annihilations at Darmstadt) Straw Tube Tracker. Strong interaction studies with antiprotons

NASA Astrophysics Data System (ADS)

Erni, W.; Keshelashvili, I.; Krusche, B.; Steinacher, M.; Heng, Y.; Liu, Z.; Liu, H.; Shen, X.; Wang, Q.; Xu, H.; Aab, A.; Albrecht, M.; Becker, J.; Csapó, A.; Feldbauer, F.; Fink, M.; Friedel, P.; Heinsius, F. H.; Held, T.; Klask, L.; Koch, H.; Kopf, B.; Leiber, S.; Leyhe, M.; Motzko, C.; Pelizäus, M.; Pychy, J.; Roth, B.; Schröder, T.; Schulze, J.; Sowa, C.; Steinke, M.; Trifterer, T.; Wiedner, U.; Zhong, J.; Beck, R.; Bianco, S.; Brinkmann, K. T.; Hammann, C.; Hinterberger, F.; Kaiser, D.; Kliemt, R.; Kube, M.; Pitka, A.; Quagli, T.; Schmidt, C.; Schmitz, R.; Schnell, R.; Thoma, U.; Vlasov, P.; Walther, D.; Wendel, C.; Würschig, T.; Zaunick, H. G.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Pantelica, D.; Pietreanu, D.; Serbina, L.; Tarta, P. D.; Kaplan, D.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Czech, B.; Kistryn, M.; Kliczewski, S.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Siudak, R.; Szczurek, A.; Jowzaee, S.; Kajetanowicz, M.; Kamys, B.; Kistryn, S.; Korcyl, G.; Korcyl, K.; Krzemien, W.; Magiera, A.; Moskal, P.; Palka, M.; Rudy, Z.; Salabura, P.; Smyrski, J.; Wrońska, A.; Augustin, I.; Lehmann, I.; Nimorus, D.; Schepers, G.; Al-Turany, M.; Arora, R.; Deppe, H.; Flemming, H.; Gerhardt, A.; Götzen, K.; Jordi, A. F.; Kalicy, G.; Karabowicz, R.; Lehmann, D.; Lewandowski, B.; Lühning, J.; Maas, F.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fedunov, A. G.; Festchenko, A. A.; Galoyan, A. S.; Grigoryan, S.; Karmokov, A.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Yu. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Mustafaev, G. A.; Olshevskiy, A.; Pasyuk, M. A.; Perevalova, E. A.; Piskun, A. A.; Pocheptsov, T. A.; Pontecorvo, G.; Rodionov, V. K.; Rogov, Yu. N.; Salmin, R. A.; Samartsev, A. G.; Sapozhnikov, M. G.; Shabratova, G. S.; Skachkova, A. N.; Skachkov, N. B.; Strokovsky, E. A.; Suleimanov, M. K.; Teshev, R. Sh.; Tokmenin, V. V.; Uzhinsky, V. V.; Vodopyanov, A. S.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Woods, P.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Dobbs, S.; Metreveli, Z.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Stancari, G.; Bianchi, N.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Orecchini, D.; Pace, E.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Bremer, D.; Dormenev, V.; Drexler, P.; Düren, M.; Eissner, T.; Föhl, K.; Galuska, M.; Gessler, T.; Hayrapetyan, A.; Hu, J.; Koch, P.; Kröck, B.; Kühn, W.; Lange, S.; Liang, Y.; Merle, O.; Metag, V.; Moritz, M.; Münchow, D.; Nanova, M.; Novotny, R.; Spruck, B.; Stenzel, H.; Ullrich, T.; Werner, M.; Xu, H.; Euan, C.; Hoek, M.; Ireland, D.; Keri, T.; Montgomery, R.; Protopopescu, D.; Rosner, G.; Seitz, B.; Babai, M.; Glazenborg-Kluttig, A.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Löhner, H.; Messchendorp, J.; Moeini, H.; Schakel, P.; Schreuder, F.; Smit, H.; Tambave, G.; van der Weele, J. C.; Veenstra, R.; Sohlbach, H.; Büscher, M.; Deermann, D.; Dosdall, R.; Esch, S.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Henssler, S.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Kozlov, V.; Lehrach, A.; Maier, R.; Mertens, M.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Randriamalala, T.; Ritman, J.; Röder, M.; Schadmand, S.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Kisiel, J.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Fissum, S.; Hansen, K.; Isaksson, L.; Lundin, M.; Schröder, B.; Achenbach, P.; Bleser, S.; Cahit, U.; Cardinali, M.; Denig, A.; Distler, M.; Fritsch, M.; Jasinski, P.; Kangh, D.; Karavdina, A.; Lauth, W.; Merkel, H.; Michel, M.; Mora Espi, M. C.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Sanchez-Lorente, A.; Schlimme, S.; Sfienti, C.; Thiel, M.; Weber, T.; Dormenev, V. I.; Fedorov, A. A.; Korzhik, M. V.; Missevitch, O. V.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Varentsov, V.; Boukharov, A.; Malyshev, O.; Marishev, I.; Semenov, A.; Böhmer, F.; Dørheim, S.; Ketzer, B.; Paul, S.; Hergemöller, A. K.; Khoukaz, A.; Köhler, E.; Täschner, A.; Wessels, J.; Varma, R.; Chaterjee, A.; Jha, V.; Kailas, S.; Roy, B. J.; Yan, Y.; Chinorat, K.; Khanchai, K.; Ayut, L.; Pomrad, S.; Baldin, E.; Kotov, K.; Peleganchuk, S.; Tikhonov, Yu.; Boucher, J.; Chambert, V.; Dbeyssi, A.; Gumberidze, M.; Hennino, T.; Imre, M.; Kunne, R.; Le Galliard, C.; Ma, B.; Marchand, D.; Maroni, A.; Ong, S.; Ramstein, B.; Rosier, P.; Tomasi-Gustafsson, E.; Van de Wiele, J.; Boca, G.; Braghieri, A.; Costanza, S.; Genova, P.; Lavezzi, L.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Konstantinov, D.; Kormilitsin, V.; Melnik, Y.; Levin, A.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Bäck, T.; Cederwall, B.; Makónyi, K.; Tegnér, P. E.; von Würtemberg, K. M.; Belostotski, S.; Gavrilov, G.; Itzotov, A.; Kashchuk, A.; Kisselev, A.; Kravchenko, P.; Levitskaya, O.; Manaenkov, S.; Miklukho, O.; Naryshkin, Y.; Veretennikov, D.; Vikhrov, V.; Zhadanov, A.; Alberto, D.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Maggiora, M.; Marcello, S.; Sosio, S.; Spataro, S.; Zotti, L.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Morra, O.; Rivetti, A.; Wheadon, R.; Iazzi, F.; Lavagno, A.; Younis, H.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Clement, H.; Galander, B.; Caldeira Balkeståhl, L.; Calén, H.; Fransson, K.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Thomé, E.; Wolke, M.; Zlomanczuk, J.; Díaz, J.; Ortiz, A.; Dmowski, K.; Duda, P.; Korzeniewski, R.; Slowinski, B.; Chlopik, A.; Guzik, Z.; Kosinski, K.; Melnychuk, D.; Wasilewski, A.; Wojciechowski, M.; Wronka, S.; Wysocka, A.; Zwieglinski, B.; Bühler, P.; Hartman, O. N.; Kienle, P.; Marton, J.; Suzuki, K.; Widmann, E.; Zmeskal, J.

2013-02-01

This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the overline{P}ANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole overline{P}ANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.

GEM detector performance and efficiency in Proton Charge Radius (PRad) Experiment

NASA Astrophysics Data System (ADS)

Bai, Xinzhan; PRad Collaboration

2017-09-01

The PRad experiment (E12-11-106) was performed in 2016 at Jefferson Lab in Hall B. It aims to investigate the proton charge radius puzzle through electron proton elastic scattering process. The experiment used a non-magnetic spectrometer method, and reached a very small ep scattering angle and thus an unprecedented small four-momentum transfer squared region, Q2 from 2 ×10-4 to 0.06(GeV / c) 2 . PRad experiment was designed to measure the proton charge radius within a sub-percent precision. Gas Electron Multiplier (GEM) detectors have contributed to reach the experimental goal. A pair of large area GEM detectors, and a large acceptance, high resolution calorimeter(HyCal) were utilized in the experiment to detect the scattered electrons. The precision requirements of the experiment demands a highly accurate understanding of efficiency and stability of GEM detectors. In this talk, we will present the preliminary results on the performance and efficiency of GEM detectors. This work is supported in part by NSF MRI award PHY-1229153, the U.S. Department of Energy under Contract No. DE-FG02-07ER41528, No. DE-FG02-03ER41240 and Thomas Jefferson National Laboratory.

Simulation of the GEM detector for BM@N experiment

NASA Astrophysics Data System (ADS)

Baranov, Dmitriy; Rogachevsky, Oleg

2017-03-01

The Gas Electron Multiplier (GEM) detector is one of the basic parts of the BM@N experiment included in the NICA project. The simulation model that takes into account features of signal generation process in an ionization GEM chamber is presented in this article. Proper parameters for the simulation were extracted from data retrieved with the help of Garfield++ (a toolkit for the detailed simulation of particle detectors). Due to this, we are able to generate clusters in layers of the micro-strip readout that correspond to clusters retrieved from a real physics experiment.

Numerical Investigation on Electron and Ion Transmission of GEM-based Detectors

NASA Astrophysics Data System (ADS)

Bhattacharya, Purba; Sahoo, Sumanya Sekhar; Biswas, Saikat; Mohanty, Bedangadas; Majumdar, Nayana; Mukhopadhyay, Supratik

2018-02-01

ALICE at the LHC is planning a major upgrade of its detector systems, including the TPC, to cope with an increase of the LHC luminosity after 2018. Different R&D activities are currently concentrated on the adoption of the Gas Electron Multiplier (GEM) as the gas amplification stage of the ALICE-TPC upgrade version. The major challenge is to have low ion feedback in the drift volume as well as to ensure a collection of good percentage of primary electrons in the signal generation process. In the present work, Garfield simulation framework has been adopted to numerically estimate the electron transparency and ion backflow fraction of GEM-based detectors. In this process, extensive simulations have been carried out to enrich our understanding of the complex physical processes occurring within single, triple and quadruple GEM detectors. A detailed study has been performed to observe the effect of detector geometry, field configuration and magnetic field on the above mentioned characteristics.

Characterization of multilayer Thick-GEM geometries as 10B converters aiming thermal neutron detection

NASA Astrophysics Data System (ADS)

Natal da Luz, H.; Souza, F. A.; Moralles, M.; Carlin, N.; Oliveira, R. A. N.; Bregant, M.; Suaide, A. A. P.; Chubaci, J. F. D.; Matsuoka, M.; Silva, T. F.; Moro, M. V.; Rodrigues, C. L.; Munhoz, M. G.

2018-02-01

Boron-based thermal neutron detectors have recently regained some attention from the instrumentation community as a strong alternative to helium-3 detectors. From the existing concepts exploiting boron layers in position sensitive detectors, the Cascade [1] is the one that takes full advantage of the 2D capabilities of gaseous detectors, with the position resolution not limited by the architecture of the detector. In this work, a proposal for the Cascade detector, based on Thick-GEMs is presented, together with some preliminary studies of the suitable pitch that optimizes the neutron conversion efficiency, while keeping the collection efficiency intact. The characterization of Thick-GEM prototypes produced in Brazil with hole pitch from 0.75 to 3 mm shows that these devices already present a stable performance at low gains, also resulting in fair energy resolution, when cascaded with a standard KaptonTM 50 µm GEM. Results of the first attempts of boron film depositions with Ion Beam Assisted Deposition and characterization by Ion Beam Analysis are also presented.

Development of a scintillating G-GEM detector for a 6-MeV X-band Linac for medical applications

NASA Astrophysics Data System (ADS)

Fujiwara, T.; Tanaka, S.; Mitsuya, Y.; Takahashi, H.; Tagi, K.; Kusano, J.; Tanabe, E.; Yamamoto, M.; Nakamura, N.; Dobashi, K.; Tomita, H.; Uesaka, M.

2013-12-01

We recently developed glass gas electron multipliers (G-GEMs) with an entirely new process using photo-etchable glass. The photo-etchable glass used for the substrate is called PEG3 (Hoya Corporation). Taking advantage of low outgassing material, we have envisioned a medical application of G-GEMs. A two-dimensional position-sensitive dosimetry system based on a scintillating gas detector is being developed for real-time dose distribution monitoring in X-ray radiation therapy. The dosimetry system consists of a chamber filled with an Ar/CF4 scintillating gas mixture, inside of which G-GEM structures are mounted. Photons produced by the excited Ar/CF4 gas molecules during the gas multiplication in the GEM holes are detected by a mirror-lens-CCD-camera system. We found that the intensity distribution of the measured light spot is proportional to the 2D dose distribution. In this work, we report on the first results from a scintillating G-GEM detector for a position-sensitive X-ray beam dosimeter.

Fast ADC based multichannel acquisition system for the GEM detector

NASA Astrophysics Data System (ADS)

Kasprowicz, G.; Czarski, T.; Chernyshova, M.; Dominik, W.; Jakubowska, K.; Karpinski, L.; Kierzkowski, K.; Pozniak, K.; Rzadkiewicz, J.; Scholz, M.; Zabolotny, W.

2012-05-01

A novel approach to the Gas Electron Multiplier1 (GEM) detector readout is presented. Unlike commonly used methods, based on discriminators, and analogue FIFOs,[ the method developed uses simultaneously sampling high speed ADCs and advanced FPGA-based processing logic to estimate the energy of every single photon. Such method is applied to every GEM strip signal. It is especially useful in case of crystal-based spectrometers for soft X-rays, where higher order reflections need to be identified and rejected. For the purpose of the detector readout, a novel conception of the measurement platform was developed.

GEM detectors for WEST and potential application for heavy impurity transport studies

NASA Astrophysics Data System (ADS)

Mazon, D.; Jardin, A.; Coston, C.; Faisse, F.; Chernyshova, M.; Czarski, T.; Kasprowicz, G.; Wojenski, A.

2016-08-01

In tokamaks equipped with metallic walls and in particular tungsten, the interplay between particle transport and MagnetoHydroDynamic (MHD) activity might lead to impurities accumulation and finally to sudden plasma termination called disruption. Studying such transport phenomena is thus essential if stationary discharges are to be achieved. On WEST a new SXR diagnostic is developed in collaboration with IPPLM (Poland) and the Warsaw University of Technology, based on a triple Gas Electron Multiplier (GEM) detector. Potential application of the WEST GEM detectors for tomographic reconstruction and subsequent transport analysis is presented.

GEM Detector Performance Assessment in the BM@N Experiment

NASA Astrophysics Data System (ADS)

Kapishin, Mikhail; Karjavin, Vladimir; Kulish, Elena; Lenivenko, Vasilisa; Makankin, Alexander; Maksymchuk, Anna; Palichik, Vladimir; Vasiliev, Sergey

2018-02-01

The Gas Electron Multiplier (GEM) chambers are developed for modern purposes in the elementary particle physics. In the BM@N experiment, a GEM system is used for the reconstruction of the trajectories of the charged particles. The investigation of GEM performance (efficiency and spatial resolution) is presented.

Data processing for soft X-ray diagnostics based on GEM detector measurements for fusion plasma imaging

NASA Astrophysics Data System (ADS)

Czarski, T.; Chernyshova, M.; Pozniak, K. T.; Kasprowicz, G.; Byszuk, A.; Juszczyk, B.; Wojenski, A.; Zabolotny, W.; Zienkiewicz, P.

2015-12-01

The measurement system based on GEM - Gas Electron Multiplier detector is developed for X-ray diagnostics of magnetic confinement fusion plasmas. The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector. The paper is focused on the measurement subject and describes the fundamental data processing to obtain reliable characteristics (histograms) useful for physicists. So, it is the software part of the project between the electronic hardware and physics applications. The project is original and it was developed by the paper authors. Multi-channel measurement system and essential data processing for X-ray energy and position recognition are considered. Several modes of data acquisition determined by hardware and software processing are introduced. Typical measuring issues are deliberated for the enhancement of data quality. The primary version based on 1-D GEM detector was applied for the high-resolution X-ray crystal spectrometer KX1 in the JET tokamak. The current version considers 2-D detector structures initially for the investigation purpose. Two detector structures with single-pixel sensors and multi-pixel (directional) sensors are considered for two-dimensional X-ray imaging. Fundamental output characteristics are presented for one and two dimensional detector structure. Representative results for reference source and tokamak plasma are demonstrated.

Operating range of a gas electron multiplier for portal imaging

NASA Astrophysics Data System (ADS)

Wallmark, M.; Brahme, A.; Danielsson, M.; Fonte, P.; Iacobaeus, C.; Peskov, V.; Östling, J.

2001-09-01

At the Karolinska Institute in Stockholm, Sweden a new detector for portal imaging is under development, which could greatly improve the alignment of the radiation beam with respect to the tumor during radiation treatment. The detector is based on solid converters combined with gas electron multipliers (GEMs) as an amplification structure. The detector has a large area and will be operated in a very high rate environment in the presence of heavy ionizing particles. As was discovered recently high rates and alpha particles could cause discharges in GEM and discharge propagation from GEM to GEM and to the readout electronics. Since reliability is one of the main requirements for the portal imaging device, we performed systematic studies to find a safe operating range of the device, free from typical high rate problems, such as discharges.

Collaborative Research: Equipment for and Running of the PSI MUSE Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohl, Michael

The R&D funding from this award has been a significant tool to move the Muon Scattering Experiment (MUSE) at the Paul Scherrer Institute in Switzerland forward to the stage of realization. Specifically, this award has enabled Dr. Michael Kohl and his working group at Hampton University to achieve substantial progress toward the goal of providing beam particle tracking with Gas Electron Multiplier (GEM) detectors for MUSE experiment. Establishing a particle detection system that is capable of operating in a high-intensity environment, with a data acquisition system capable of running at several kHz, combined with robust tracking software providing high efficiencymore » for track reconstruction in the presence of noise and backgrounds will have immediate application in many other experiments.« less

Readout electronics for the GEM detector

NASA Astrophysics Data System (ADS)

Kasprowicz, G.; Czarski, T.; Chernyshova, M.; Czyrkowski, H.; Dabrowski, R.; Dominik, W.; Jakubowska, K.; Karpinski, L.; Kierzkowski, K.; Kudla, I. M.; Pozniak, K.; Rzadkiewicz, J.; Salapa, Z.; Scholz, M.; Zabolotny, W.

2011-10-01

A novel approach to the Gas Electron Multiplier (GEM) detector readout is presented. Unlike commonly used methods, based on discriminators[2],[3] and analogue FIFOs[1], the method developed uses simultaneously sampling high speed ADCs and advanced FPGA-based processing logic to estimate the energy of every single photon. Such method is applied to every GEM strip signal. It is especially useful in case of crystal-based spectrometers for soft X-rays, where higher order reflections need to be identified and rejected[5].

The Hadron Blind Ring Imaging Cherenkov Detector

NASA Astrophysics Data System (ADS)

Blatnik, Marie; Zajac, Stephanie; Hemmick, Tom

2013-10-01

Heavy Ion Collisions in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab have hinted at the existence of a new form of matter at high gluon density, the Color Glass Condensate. High energy electron scattering off of nuclei, focusing on the low-x components of the nuclear wave function, will definitively measure this state of matter. However, when a nucleus contributes a low x parton, the reaction products are highly focused in the electron-going direction and have large momentum in the lab system. High-momentum particle identification is particularly challenging. A particle is identifiable by its mass, but tracking algorithms only yield a particle's momentum based on its track's curvature. The particle's velocity is needed to identify the particle. A ring-imaging Cerenkov detector is being developed for the forward angle particle identification from the technological advancements of PHENIX's Hadron-Blind Detector (HBD), which uses Gas Electron Multipliers (GEMs) and pixelated pad planes to detect Cerenkov photons. The new HBD will focus the Cerenkov photons into a ring to determine the parent particle's velocity. Results from the pad plane simulations, construction tests, and test beam run will be presented.

Neutron diffraction measurements on a reference metallic sample with a high-efficiency GEM side-on 10B-based thermal neutron detector

NASA Astrophysics Data System (ADS)

Pietropaolo, A.; Claps, G.; Fedrigo, A.; Grazzi, F.; Höglund, C.; Murtas, F.; Scherillo, A.; Schmidt, S.; Schooneveld, E. M.

2018-03-01

The upgraded version of the GEM side-on thermal neutron detector was successfully tested in a neutron diffraction experiment on a reference sample using the INES diffractometer at the ISIS spallation neutron source, UK. The performance of the new 10B4C-based detector is compared to that of a standard 3He tube, operating at the instrument as a part of the detectors assembly. The results show that the upgraded detector has a better resolution and an efficiency of the same order of magnitude of a 3He-based detector.

Design Improvements and X-Ray Performance of a Time Projection Chamber Polarimeter for Persistent Astronomical Sources

NASA Technical Reports Server (NTRS)

Hill, Joanne E.; Black, J. Kevin; Emmett, Thomas J.; Enoto, Teruaki; Jahoda, Keith M.; Kaaret, Philip; Nolan, David S.; Tamagawa, Toru

2014-01-01

The design of the Time-Projection Chamber (TPC) Polarimeter for the Gravity and Extreme Magnetism Small Explorer (GEMS) was demonstrated to Technology Readiness Level 6 (TRL-6)3 and the flight detectors fabricated, assembled and performance tested. A single flight detector was characterized at the Brookhaven National Laboratory Synchrotron Light Source with polarized X-rays at 10 energies from 2.3-8.0 keV at five detector positions. The detector met all of the GEMS performance requirements. Lifetime measurements have shown that the existing flight design has 23 years of lifetime4, opening up the possibility of relaxing material requirements, in particular the consideration of the use of epoxy, to reduce risk elsewhere. We report on design improvements to the GEMS detector to enable a narrower transfer gap that, when operated with a lower transfer field, reduces asymmetries in the detector response. In addition, the new design reduces cost and risk by simplifying the assembly and reducing production time. Finally, we report on the performance of the narrow-gap detector in response to polarized and unpolarized X-rays.

TACTIC: the TRIUMF Annular Chamber for Tracking and Identification of Charged particles

NASA Astrophysics Data System (ADS)

Martin, L.; Ruprecht, G.; Hager, U.; Amaudruz, P.-A.; Buchmann, L.; Fox, S. P.; Laird, A. M.; Martin, E.

2018-01-01

An in-depth characterization of the TACTIC detector was performed using data from a 148Gd alpha source and some test runs with a stable ion beam. The detector is an active target time-projection chamber with a blind central region for maximizing beam tolerance and GEM-based electron amplification, equipped with a modern digitizing data acquisition system allowing the recording of full signals. The system was developed to study the reaction 8Li(α,n)11B, which is important for bridging the mass 8 gap in scenarios of low 4He density like Inhomogeneous Big Bang Nucleosynthesis and the production of r-process seeds in supernovae. Both energy resolution and tracking accuracy were found to agree with theoretical predictions and Geant4 simulations. The 8Li beam rate capability of the system is predicted to be of the order of 105s-1, several orders of magnitude higher than most previous measurements of the same reaction, while still maintaining a high detection efficiency of 70% to 80 %.

A geopotential model from satellite tracking, altimeter, and surface gravity data: GEM-T3

NASA Technical Reports Server (NTRS)

Lerch, F. J.; Nerem, R. S.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Marshall, J. A.; Klosko, S. M.; Patel, G. B.; Williamson, R. G.; Chinn, D. S.

1994-01-01

An improved model of Earth's gravitational field, Goddard Earth Model T-3 (GEM-T3), has been developed from a combination of satellite tracking, satellite altimeter, and surface gravimetric data. GEM-T3 provides a significant improvement in the modeling of the gravity field at half wavelengths of 400 km and longer. This model, complete to degree and order 50, yields more accurate satellite orbits and an improved geoid representation than previous Goddard Earth Models. GEM-T3 uses altimeter data from GEOS 3 (1975-1976), Seasat (1978) and Geosat (1986-1987). Tracking information used in the solution includes more than 1300 arcs of data encompassing 31 different satellites. The recovery of the long-wavelength components of the solution relies mostly on highly precise satellite laser ranging (SLR) data, but also includes Tracking Network (TRANET) Doppler, optical, and satellite-to-satellite tracking acquired between the ATS 6 and GEOS 3 satellites. The main advances over GEM-T2 (beyond the inclusion of altimeter and surface gravity information which is essential for the resolution of the shorter wavelength geoid) are some improved tracking data analysis approaches and additional SLR data. Although the use of altimeter data has greatly enhanced the modeling of the ocean geoid between 65 deg N and 60 deg S latitudes in GEM-T3, the lack of accurate detailed surface gravimetry leaves poor geoid resolution over many continental regions of great tectonic interest (e.g., Himalayas, Andes). Estimates of polar motion, tracking station coordinates, and long-wavelength ocean tidal terms were also made (accounting for 6330 parameters). GEM-T3 has undergone error calibration using a technique based on subset solutions to produce reliable error estimates. The calibration is based on the condition that the expected mean square deviation of a subset gravity solution from the full set values is predicted by the solutions' error covariances. Data weights are iteratively adjusted until this condition for the error calibration is satisfied. In addition, gravity field tests were performed on strong satellite data sets withheld from the solution (thereby ensuring their independence). In these tests, the performance of the subset models on the withheld observations is compared to error projections based on their calibrated error covariances. These results demonstrate that orbit accuracy projections are reliable for new satellites which were not included in GEM-T3.

Simulation of energy spectrum of GEM detector from an x-ray quantum

NASA Astrophysics Data System (ADS)

Malinowski, K.; Chernyshova, M.; Czarski, T.; Kowalska-Strzęciwilk, E.; Linczuk, P.; Wojeński, A.; Krawczyk, R.; Gąska, M.

2018-01-01

This paper presents the results of the energy resolution simulation for the triple GEM-based detector for x-ray quantum of 5.9 keV . Photons of this energy are emitted by 55Fe source, which is a standard calibration marker for this type of detectors. The calculations were made in Garfield++ in two stages. In the first stage, the distribution of the amount of primary electrons generated in the drift volume by the x-ray quantum was simulated using the Heed program. Secondly, the primary electrons of the resulting quantitative distribution were treated as a source of electron avalanches propagated through the whole volume of the triple GEM-based detector. The distribution of the obtained signals created a spectrum corresponding to the peak at 5.9 keV, which allowed us to determine the theoretical energy resolution of the detector. Its knowledge allows observing and improving the eventual experimental deterioration of the energy resolution, inevitably accompanying processes of registration and processing of the signals.

Negative Ion Time Projection Chamber operation with SF6 at nearly atmospheric pressure

NASA Astrophysics Data System (ADS)

Baracchini, E.; Cavoto, G.; Mazzitelli, G.; Murtas, F.; Renga, F.; Tomassini, S.

2018-04-01

We present the measurement of negative ion drift velocities and mobilities for innovative particle tracking detectors using gas mixtures based on SF6. This gas has recently received attention in the context of directional Dark Matter searches, thanks to its high Fluorine content, reduced diffusion and multiple species of charge carriers, which allow for full detector fiducialization. Our measurements, performed with a 5 cm drift distance Negative Ion Time Projection Chamber, show the possibility of negative ion operation in pure SF6 between 75 and 150 Torr with triple thin GEM amplification, confirming the attractive potentialities of this gas. Above all, our results with the mixture He:CF4:SF6 360:240:10 Torr demonstrate for the first time the feasibility of SF6‑ negative ion drift and gas gain in He at nearly atmospheric pressure, opening very interesting prospects for the next generation of directional Dark Matter detectors.

Fast modular data acquisition system for GEM-2D detector

NASA Astrophysics Data System (ADS)

Kasprowicz, G.; Byszuk, Adrian; Wojeński, A.; Zienkiewicz, P.; Czarski, T.; Chernyshova, M.; Poźniak, K.; Rzadkiewicz, J.; Zabolotny, W.; Juszczyk, B.

2014-11-01

A novel approach to two dimensional Gas Electron Multiplier (GEM) detector readout is presented. Unlike commonly used methods, based on discriminators and analogue FIFOs, the method developed uses simulta- neously sampling high speed ADCs with fast hybrid integrator and advanced FPGA-based processing logic to estimate the energy of every single photon. Such a method is applied to every GEM strip / pixel signal. It is especially useful in case of crystal-based spectrometers for soft X-rays, 2D imaging for plasma tomography and all these applications where energy resolution of every single photon is required. For the purpose of the detector readout, a novel, highly modular and extendable conception of the measurement platform was developed. It is evolution of already deployed measurement system for JET Spectrometer.

GEM detector development for tokamak plasma radiation diagnostics: SXR poloidal tomography

NASA Astrophysics Data System (ADS)

Chernyshova, Maryna; Malinowski, Karol; Ziółkowski, Adam; Kowalska-Strzeciwilk, Ewa; Czarski, Tomasz; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Zabołotny, Wojciech; Wojeński, Andrzej; Kolasiński, Piotr; Krawczyk, Rafał D.

2015-09-01

An increased attention to tungsten material is related to a fact that it became a main candidate for the plasma facing material in ITER and future fusion reactor. The proposed work refers to the studies of W influence on the plasma performances by developing new detectors based on Gas Electron Multiplier GEM) technology for tomographic studies of tungsten transport in ITER-oriented tokamaks, e.g. WEST project. It presents current stage of design and developing of cylindrically bent SXR GEM detector construction for horizontal port implementation. Concept to overcome an influence of constraints on vertical port has been also presented. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing creation of sustainable nuclear fusion reactors a step closer.

Performance of the full size nGEM detector for the SPIDER experiment

NASA Astrophysics Data System (ADS)

Muraro, A.; Croci, G.; Albani, G.; Claps, G.; Cavenago, M.; Cazzaniga, C.; Dalla Palma, M.; Grosso, G.; Murtas, F.; Pasqualotto, R.; Perelli Cippo, E.; Rebai, M.; Tardocchi, M.; Tollin, M.; Gorini, G.

2016-03-01

The ITER neutral beam test facility under construction in Padova will host two experimental devices: SPIDER, a 100 kV negative H/D RF beam source, and MITICA, a full scale, 1 MeV deuterium beam injector. SPIDER will start operations in 2016 while MITICA is expected to start during 2019. Both devices feature a beam dump used to stop the produced deuteron beam. Detection of fusion neutrons produced between beam-deuterons and dump-implanted deuterons will be used as a means to resolve the horizontal beam intensity profile. The neutron detection system will be placed right behind the beam dump, as close to the neutron emitting surface as possible thus providing the map of the neutron emission on the beam dump surface. The system uses nGEM neutron detectors. These are Gas Electron Multiplier detectors equipped with a cathode that also serves as neutron-proton converter foil. The cathode is designed to ensure that most of the detected neutrons at a point of the nGEM surface are emitted from the corresponding beamlet footprint (with dimensions of about 40×22 mm2) on the dump front surface. The size of the nGEM detector for SPIDER is 352 mm×200 mm. Several smaller size prototypes have been successfully made in the last years and the experience gained on these detectors has led to the production of the full size detector for SPIDER during 2014. This nGEM has a read-out board made of 256 pads (arranged in a 16×16 matrix) each with a dimension of 22 mm×13 mm. This paper describes the production of this detector and its tests (in terms of beam profile reconstruction capability, uniformity over the active area, gamma rejection capability and time stability) performed on the ROTAX beam-line at the ISIS spallation source (Didcot-UK).

Interface of the general fitting tool GENFIT2 in PandaRoot

NASA Astrophysics Data System (ADS)

Prencipe, Elisabetta; Spataro, Stefano; Stockmanns, Tobias; PANDA Collaboration

2017-10-01

\\bar{{{P}}}ANDA is a planned experiment at FAIR (Darmstadt) with a cooled antiproton beam in a range [1.5; 15] GeV/c, allowing a wide physics program in nuclear and particle physics. It is the only experiment worldwide, which combines a solenoid field (B=2T) and a dipole field (B=2Tm) in a spectrometer with a fixed target topology, in that energy regime. The tracking system of \\bar{{{P}}}ANDA involves the presence of a high performance silicon vertex detector, a GEM detector, a straw-tubes central tracker, a forward tracking system, and a luminosity monitor. The offline tracking algorithm is developed within the PandaRoot framework, which is a part of the FairRoot project. The tool here presented is based on algorithms containing the Kalman Filter equations and a deterministic annealing filter. This general fitting tool (GENFIT2) offers to users also a Runge-Kutta track representation, and interfaces with Millepede II (useful for alignment) and RAVE (vertex finder). It is independent on the detector geometry and the magnetic field map, and written in C++ object-oriented modular code. Several fitting algorithms are available with GENFIT2, with user-adjustable parameters; therefore the tool is of friendly usage. A check on the fit convergence is done by GENFIT2 as well. The Kalman-Filter-based algorithms have a wide range of applications; among those in particle physics they can perform extrapolations of track parameters and covariance matrices. The adoptions of the PandaRoot framework to connect to Genfit2 are described, and the impact of GENFIT2 on the physics simulations of \\bar{{{P}}}ANDA are shown: significant improvement is reported for those channels where a good low momentum tracking is required (pT < 400 MeV/c).

Status of the KLOE-2 Inner Tracker

NASA Astrophysics Data System (ADS)

De Lucia, Erika

2018-01-01

KLOE-2 at the DAΦNE Φ-factory is the main experiment of the INFN Laboratori Nazionali di Frascati (LNF) and is the first high-energy experiment using the GEM technology with a cylindrical geometry, a novel idea developed at LNF. Four concentric cylindrical triple-GEM detectors compose the Inner Tracker, inserted around the interaction region and before the inner wall of the pre-existing KLOE Drift Chamber to improve the resolution on decay vertices close to the interaction point. State-of-the-art solutions have been expressly developed or tuned for this project: single-mask GEM etching, multi-layer XV patterned readout, PEEK spacer grid, GASTONE front-end board, a custom 64-channel ASIC with digital output, and the Global Interface Board for data collection, with a configurable FPGA architecture and Gigabit Ethernet. Alignment and calibration of a cylindrical GEM detector was never done before and represents one of the challenging activities of the experiment. The Inner Tracker detector construction, operation, calibration and performance obtained with cosmic-ray muons and Bhabha scattering events will be reported.

The development of algorithms for the deployment of new version of GEM-detector-based acquisition system

NASA Astrophysics Data System (ADS)

Krawczyk, Rafał D.; Czarski, Tomasz; Kolasiński, Piotr; Linczuk, Paweł; Poźniak, Krzysztof T.; Chernyshova, Maryna; Kasprowicz, Grzegorz; Wojeński, Andrzej; Zabolotny, Wojciech; Zienkiewicz, Paweł

2016-09-01

This article is an overview of what has been implemented in the process of development and testing the GEM detector based acquisition system in terms of post-processing algorithms. Information is given on mex functions for extended statistics collection, unified hex topology and optimized S-DAQ algorithm for splitting overlapped signals. Additional discussion on bottlenecks and major factors concerning optimization is presented.

An improved model of the Earth's gravity field - GEM-T3

NASA Technical Reports Server (NTRS)

Nerem, R. S.; Lerch, F. J.; Putney, B. H.; Klosko, S. M.; Patel, G. B.; Williamson, R. G.; Pavlis, E. C.

1992-01-01

An improved model of the Earth's gravitational field is developed from a combination of conventional satellite tracking, satellite altimeter measurements, and surface gravimetric data (GEM-T3). This model gives improved performance for the computation of satellite orbital effects as well as a superior representation of the geoid from that achieved in any previous Goddard Earth Model. The GEM-T3 model uses altimeter data directly to define the orbits, geoid, and dynamic height fields. Altimeter data acquired during the GEOS-3 (1975-1976), SEASAT (1978), and GEOSAT (1986-1987) missions were used to compute GEM-T3. In order to accommodate the non-gravitational signal mapped by these altimeters, spherical harmonic models of the dynamic height of the ocean surface were recovered for each mission simultaneously with the gravitational field. The tracking data utilized in the solution includes more than 1300 arcs of data encompassing 31 different satellites. The observational data base is highly dependent on SLR, but also includes TRANET Doppler, optical, S-Band average range-rate and satellite-to-satellite tracking acquired between ATS-6 and GEOS-3. The GEM-T3 model has undergone extensive error calibration.

Application of GEM-based detectors in full-field XRF imaging

NASA Astrophysics Data System (ADS)

Dąbrowski, W.; Fiutowski, T.; Frączek, P.; Koperny, S.; Lankosz, M.; Mendys, A.; Mindur, B.; Świentek, K.; Wiącek, P.; Wróbel, P. M.

2016-12-01

X-ray fluorescence spectroscopy (XRF) is a commonly used technique for non-destructive elemental analysis of cultural heritage objects. It can be applied to investigations of provenance of historical objects as well as to studies of art techniques. While the XRF analysis can be easily performed locally using standard available equipment there is a growing interest in imaging of spatial distribution of specific elements. Spatial imaging of elemental distrbutions is usually realised by scanning an object with a narrow focused X-ray excitation beam and measuring characteristic fluorescence radiation using a high energy resolution detector, usually a silicon drift detector. Such a technique, called macro-XRF imaging, is suitable for investigation of flat surfaces but it is time consuming because the spatial resolution is basically determined by the spot size of the beam. Another approach is the full-field XRF, which is based on simultaneous irradiation and imaging of large area of an object. The image of the investigated area is projected by a pinhole camera on a position-sensitive and energy dispersive detector. The infinite depth of field of the pinhole camera allows one, in principle, investigation of non-flat surfaces. One of possible detectors to be employed in full-field XRF imaging is a GEM based detector with 2-dimensional readout. In the paper we report on development of an imaging system equipped with a standard 3-stage GEM detector of 10 × 10 cm2 equipped with readout electronics based on dedicated full-custom ASICs and DAQ system. With a demonstrator system we have obtained 2-D spatial resolution of the order of 100 μm and energy resolution at a level of 20% FWHM for 5.9 keV . Limitations of such a detector due to copper fluorescence radiation excited in the copper-clad drift electrode and GEM foils is discussed and performance of the detector using chromium-clad electrodes is reported.

The GEM-T2 gravitational model

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Lerch, F. J.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Klosko, S. M.; Patel, G. B.; Robbins, J. W.; Williamson, R. G.; Engelis, T. E.

1989-01-01

The GEM-T2 is the latest in a series of Goddard Earth Models of the terrestrial field. It was designed to bring modeling capabilities one step closer towards ultimately determining the TOPEX/Poseidon satellite's radial position to an accuracy of 10-cm RMS (root mean square). It also improves models of the long wavelength geoid to support many oceanographic and geophysical applications. The GEM-T2 extends the spherical harmonic field to include more than 600 coefficients above degree 36 (which was the limit for its predecessor, GEM-T1). Like GEM-T1, it was produced entirely from satellite tracking data, but it now uses nearly twice as many satellites (31 vs. 17), contains four times the number of observations (2.4 million), has twice the number of data arcs (1132), and utilizes precise laser tracking from 11 satellites. The estimation technique for the solution has been augmented to include an optimum data weighting procedure with automatic error calibration for the gravitational parameters. Results for the GEM-T2 error calibration indicate significant improvement over previous satellite-only models. The error of commission in determining the geoid has been reduced from 155 cm in GEM-T1 to 105 cm for GEM-T2 for the 36 x 36 portion of the field, and 141 cm for the entire model. The orbital accuracies achieved using GEM-T2 are likewise improved. Also, the projected radial error on the TOPEX satellite orbit indicates 9.4 cm RMS for GEM-T2, compared to 24.1 cm for GEM-T1.

The MONDO project: A secondary neutron tracker detector for particle therapy

NASA Astrophysics Data System (ADS)

Valle, S. M.; Battistoni, G.; Patera, V.; Pinci, D.; Sarti, A.; Sciubba, A.; Spiriti, E.; Marafini, M.

2017-02-01

During Particle Therapy treatments the patient irradiation produces, among different types of secondary radiation, an abundant flux of neutrons that can release a significant dose far away from the tumour region. A precise measurement of their flux, energy and angle distributions is eagerly needed in order to improve the Treatment Planning Systems software and to properly take into account the risk of late complications in the whole body. The technical challenges posed by a neutron detector aiming for high detection efficiency and good backtracking precision will be addressed within the MONDO project, whose main goal is to develop a tracking detector targeting fast and ultra-fast secondary neutrons. The neutron tracking principle is based on the reconstruction of two consequent elastic scattering interactions of a neutron with a target material. Reconstructing the recoiling protons it is hence possible to measure the energy and incoming direction of the neutron. Plastic scintillators will be used as scattering and detection media: the tracker is being developed as a matrix of squared scintillating fibres of 250 μm side. The light produced and collected in fibres will be amplified using a triple GEM-based image intensifier and acquired using CMOS Single Photon Avalanche Diode arrays. Using therapeutic beams, the principal detector goal will be the measurement of the neutron production yields, as a function of production angle and energy.

Data processing and analysis for 2D imaging GEM detector system

NASA Astrophysics Data System (ADS)

Czarski, T.; Chernyshova, M.; Pozniak, K. T.; Kasprowicz, G.; Byszuk, A.; Juszczyk, B.; Kolasinski, P.; Linczuk, M.; Wojenski, A.; Zabolotny, W.; Zienkiewicz, P.

2014-11-01

The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector for high-resolution X-ray diagnostics of magnetic confinement fusion plasmas [1]. Multi-channel measurement system and essential data processing for X-ray energy and position recognition is consider. Several modes of data acquisition are introduced depending on processing division for hardware and software components. Typical measuring issues aredeliberated for enhancement of data quality. Fundamental output characteristics are presented for one and two dimensional detector structure. Representative results for reference X-ray source and tokamak plasma are demonstrated.

A GEM-TPC in twin configuration for the Super-FRS tracking of heavy ions at FAIR

NASA Astrophysics Data System (ADS)

García, F.; Grahn, T.; Hoffmann, J.; Jokinen, A.; Kaya, C.; Kunkel, J.; Rinta-Antila, S.; Risch, H.; Rusanov, I.; Schmidt, C. J.; Simon, H.; Simons, C.; Turpeinen, R.; Voss, B.; Äystö, J.; Winkler, M.

2018-03-01

The GEM-TPC described herein will be part of the standard beam-diagnostics equipment of the Super-FRS. This chamber will provide tracking information for particle identification at rates up to 1 MHz on an event-by-event basis. The key requirements of operation for these chambers are: close to 100% tracking efficiency under conditions of high counting rate, spatial resolution below 1 mm and a superb large dynamic range covering projectiles from Z = 1 up to Z = 92. The current prototype consists of two GEM-TPCs inside a single vessel, which are operating independently and have electrical drift fields in opposite directions. The twin configuration is done by flipping one of the GEM-TPCs on the middle plane with respect to the second one. In order to put this development in context, the evolution of previous prototypes will be described and its performances discussed. Finally, this chamber was tested at the University of Jyväskylä accelerator with proton projectiles and at GSI with Uranium, Xenon, fragments and Carbon beams. The results obtained have shown a position resolution between 120 to 300 μm at moderate counting rate under conditions of full tracking efficiency.

Serial data acquisition for GEM-2D detector

NASA Astrophysics Data System (ADS)

Kolasinski, Piotr; Pozniak, Krzysztof T.; Czarski, Tomasz; Linczuk, Maciej; Byszuk, Adrian; Chernyshova, Maryna; Juszczyk, Bartlomiej; Kasprowicz, Grzegorz; Wojenski, Andrzej; Zabolotny, Wojciech; Zienkiewicz, Pawel; Mazon, Didier; Malard, Philippe; Herrmann, Albrecht; Vezinet, Didier

2014-11-01

This article debates about data fast acquisition and histogramming method for the X-ray GEM detector. The whole process of histogramming is performed by FPGA chips (Spartan-6 series from Xilinx). The results of the histogramming process are stored in an internal FPGA memory and then sent to PC. In PC data is merged and processed by MATLAB. The structure of firmware functionality implemented in the FPGAs is described. Examples of test measurements and results are presented.

Gas electron multiplier (GEM) enhanced ionization chamber for fluorescence detector

NASA Astrophysics Data System (ADS)

Shaban, E. H.; Siddons, D. P.; Kuczewski, A.

2007-11-01

Detecting dilute elements in thin materials using extended X-ray absorption fluorescence spectroscopy (EXAFS) method requires a detector capable of high count rate and low noise. For detection of dilute elements, the fluorescence signal amplitude is often overcome by the presence of noise or background interference. In this paper we have used a gas ionization chamber enhanced by a gas electron multiplier (GEM) to amplify the primary ionized electrons due to the X-ray fluorescence of a dilute element. The GEM provides an essentially noise free electron amplification of the signal primary photoelectrons. It provides a larger output current prior to the electronic amplification, allowing a lower gain amplifier with lower electronic circuit noise contribution and hence improved S/ N ratio. In addition, since the signal is produced only by electrons, and not from ion motion, the detector is capable of recording rapidly changing signals. Iron in an arbitrary tree leaf was used as a test sample. This sample was measured using our detector SUBRSAB, and also with Lytle and passivated implanted planar silicon (PIPS) detectors. An improvement in the signal amplitude by a factor of 20 and a factor of 2 are recorded for the proposed detector with respect to the Lytle and PIPS detectors, respectively. Although the gain in signal over the PIPS detector is small for this detector, its lack of sensitivity to light and its low and temperature-independent dark current are further advantages.

X-ray GEM Detectors for Burning Plasma Experiments

NASA Astrophysics Data System (ADS)

Puddu, S.; Bombarda, F.; Pizzicaroli, G.; Murtas, F.

2009-11-01

The harsh environment and higher values of plasma parameters to be expected in future burning plasma experiments (and even more so in future power producing fusion reactors) is prompting the development of new, advanced diagnostic systems. The detection of radiation emitted by the plasma in the X-ray spectral region is likely to play the role that visible or UV radiation have in present day experiments. GEM gas detectors, developed at CERN, are the natural evolution of Multiwire Proportional Chambers, with a number of advantages: higher counting rates, lower noise, good energy resolution, low sensitivity to background radiation. GEM's can be used in several different ways, but two specific applications are being explored in the framework of the Ignitor program, one for plasma position control and the other for high resolution spectroscopy. The diagnostic layout on the Ignitor machine is such that the detectors will not be in direct view of the plasma, at locations where they can be efficiently screened by the background radiation. Prototype detectors 10 x 10 cm^2 in area have been assembled and will be tested to assess the optimal geometrical parameters and operating conditions, regarding in particular the choice between Single and Triple GEM configurations, the gas mixture, and the problem of fan-out associated with the high number of output channels required for high resolution crystal spectrometers.

Gravitational field modes GEM 3 and 4

NASA Technical Reports Server (NTRS)

Lerch, F. J.; Wagner, C. A.; Putney, B. H.; Sandson, M. L.; Brownd, J. E.; Richardson, J. A.; Taylor, W. A.

1972-01-01

A refinement in the satellite geopotential solution for a Goddard Earth Model (GEM 3) was obtained. The solution includes the addition of two low inclination satellites, SAS at 3 deg and PEOLE at 15 deg, and is based upon 27 close earth satellites containing some 400,000 observations of electronic, laser, and optical data. In addition, a new combination satellite/gravimetry solution (GEM 4) was derived. The new model includes 61 center of mass tracking station locations with data from GRARR, Laser, MOTS, Baker-Nunn, and NWL Tranet Doppler tracking sites. Improvement was obtained for the zonal coefficients of the new models and is shown by tests on the long period perturbations of the orbits. Individual zonal coefficients agree very closely among different models that contain low inclination satellites. Tests of models with surface gravity data show that the GEM 3 satellite model has significantly better agreement with the gravimetry data than the GEM 1 satellite model, and that it also has better agreement with the gravimetry data than the 1969 SAO Standard Earth 2 model.

Study of solid-conversion gaseous detector based on GEM for high energy X-ray industrial CT.

PubMed

Zhou, Rifeng; Zhou, Yaling

2014-01-01

The general gaseous ionization detectors are not suitable for high energy X-ray industrial computed tomography (HEICT) because of their inherent limitations, especially low detective efficiency and large volume. The goal of this study was to investigate a new type of gaseous detector to solve these problems. The novel detector was made by a metal foil as X-ray convertor to improve the conversion efficiency, and the Gas Electron Multiplier (hereinafter "GEM") was used as electron amplifier to lessen its volume. The detective mechanism and signal formation of the detector was discussed in detail. The conversion efficiency was calculated by using EGSnrc Monte Carlo code, and the transport course of photon and secondary electron avalanche in the detector was simulated with the Maxwell and Garfield codes. The result indicated that this detector has higher conversion efficiency as well as less volume. Theoretically this kind of detector could be a perfect candidate for replacing the conventional detector in HEICT.

Fast data transmission from serial data acquisition for the GEM detector system

NASA Astrophysics Data System (ADS)

Kolasinski, Piotr; Pozniak, Krzysztof T.; Czarski, Tomasz; Byszuk, Adrian; Chernyshova, Maryna; Kasprowicz, Grzegorz; Krawczyk, Rafal D.; Wojenski, Andrzej; Zabolotny, Wojciech

2015-09-01

This article proposes new method of storing data and transferring it to PC in the X-ray GEM detector system. The whole process is performed by FPGA chips (Spartan-6 series from Xilinx). Comparing to previous methods, new approach allows to store much more data in the system. New, improved implementation of the communication algorithm significantly increases transfer rate between system and PC. In PC data is merged and processed by MATLAB. The structure of firmware implemented in the FPGAs is described.

Reconstruction of Micropattern Detector Signals using Convolutional Neural Networks

NASA Astrophysics Data System (ADS)

Flekova, L.; Schott, M.

2017-10-01

Micropattern gaseous detector (MPGD) technologies, such as GEMs or MicroMegas, are particularly suitable for precision tracking and triggering in high rate environments. Given their relatively low production costs, MPGDs are an exemplary candidate for the next generation of particle detectors. Having acknowledged these advantages, both the ATLAS and CMS collaborations at the LHC are exploiting these new technologies for their detector upgrade programs in the coming years. When MPGDs are utilized for triggering purposes, the measured signals need to be precisely reconstructed within less than 200 ns, which can be achieved by the usage of FPGAs. In this work, we present a novel approach to identify reconstructed signals, their timing and the corresponding spatial position on the detector. In particular, we study the effect of noise and dead readout strips on the reconstruction performance. Our approach leverages the potential of convolutional neural network (CNNs), which have recently manifested an outstanding performance in a range of modeling tasks. The proposed neural network architecture of our CNN is designed simply enough, so that it can be modeled directly by an FPGA and thus provide precise information on reconstructed signals already in trigger level.

Lifetime Estimation of a Time Projection Chamber X-ray Polarimeter

NASA Technical Reports Server (NTRS)

Hill, Joanne E.; Black, J. Kevin; Brieda, Lubos; Dickens, Patsy L.; deGarcia, Kristina Montt; Hawk, Douglas L.; Hayato, Asami; Jahoda, Keith; Mohammed, Jelila

2013-01-01

The Gravity and Extreme Magnetism Small Explorer (GEMS) X-ray polarimeter Instrument (XPI) was designed to measure the polarization of 23 sources over the course of its 9 month mission. The XPI design consists of two telescopes each with a polarimeter assembly at the focus of a grazing incidence mirror. To make sensitive polarization measurements the GEMS Polarimeter Assembly (PA) employed a gas detection system based on a Time Projection Chamber (TPC) technique. Gas detectors are inherently at risk of degraded performance arising from contamination from outgassing of internal detector components or due to loss of gas. This paper describes the design and the materials used to build a prototype of the flight polarimeter with the required GEMS lifetime. We report the results from outgassing measurements of the polarimeter subassemblies and assemblies, enclosure seal tests, life tests, and performance tests that demonstrate that the GEMS lifetime is achievable. Finally we report performance measurements and the lifetime enhancement from the use of a getter.

A scintillating gas detector for 2D dose measurements in clinical carbon beams.

PubMed

Seravalli, E; de Boer, M; Geurink, F; Huizenga, J; Kreuger, R; Schippers, J M; van Eijk, C W E; Voss, B

2008-09-07

A two-dimensional position sensitive dosimetry system based on a scintillating gas detector has been developed for pre-treatment verification of dose distributions in hadron therapy. The dosimetry system consists of a chamber filled with an Ar/CF4 scintillating gas mixture, inside which two cascaded gas electron multipliers (GEMs) are mounted. A GEM is a thin kapton foil with copper cladding structured with a regular pattern of sub-mm holes. The primary electrons, created in the detector's sensitive volume by the incoming beam, drift in an electric field towards the GEMs and undergo gas multiplication in the GEM holes. During this process, photons are emitted by the excited Ar/CF4 gas molecules and detected by a mirror-lens-CCD camera system. Since the amount of emitted light is proportional to the dose deposited in the sensitive volume of the detector by the incoming beam, the intensity distribution of the measured light spot is proportional to the 2D hadron dose distribution. For a measurement of a 3D dose distribution, the scintillating gas detector is mounted at the beam exit side of a water-bellows phantom, whose thickness can be varied in steps. In this work, the energy dependence of the output signal of the scintillating gas detector has been verified in a 250 MeV/u clinical 12C ion beam by means of a depth-dose curve measurement. The underestimation of the measured signal at the Bragg peak depth is only 9% with respect to an air-filled ionization chamber. This is much smaller than the underestimation found for a scintillating Gd2O2S:Tb ('Lanex') screen under the same measurement conditions (43%). Consequently, the scintillating gas detector is a promising device for verifying dose distributions in high LET beams, for example to check hadron therapy treatment plans which comprise beams with different energies.

A scintillating gas detector for 2D dose measurements in clinical carbon beams

NASA Astrophysics Data System (ADS)

Seravalli, E.; de Boer, M.; Geurink, F.; Huizenga, J.; Kreuger, R.; Schippers, J. M.; van Eijk, C. W. E.; Voss, B.

2008-09-01

A two-dimensional position sensitive dosimetry system based on a scintillating gas detector has been developed for pre-treatment verification of dose distributions in hadron therapy. The dosimetry system consists of a chamber filled with an Ar/CF4 scintillating gas mixture, inside which two cascaded gas electron multipliers (GEMs) are mounted. A GEM is a thin kapton foil with copper cladding structured with a regular pattern of sub-mm holes. The primary electrons, created in the detector's sensitive volume by the incoming beam, drift in an electric field towards the GEMs and undergo gas multiplication in the GEM holes. During this process, photons are emitted by the excited Ar/CF4 gas molecules and detected by a mirror-lens-CCD camera system. Since the amount of emitted light is proportional to the dose deposited in the sensitive volume of the detector by the incoming beam, the intensity distribution of the measured light spot is proportional to the 2D hadron dose distribution. For a measurement of a 3D dose distribution, the scintillating gas detector is mounted at the beam exit side of a water-bellows phantom, whose thickness can be varied in steps. In this work, the energy dependence of the output signal of the scintillating gas detector has been verified in a 250 MeV/u clinical 12C ion beam by means of a depth-dose curve measurement. The underestimation of the measured signal at the Bragg peak depth is only 9% with respect to an air-filled ionization chamber. This is much smaller than the underestimation found for a scintillating Gd2O2S:Tb ('Lanex') screen under the same measurement conditions (43%). Consequently, the scintillating gas detector is a promising device for verifying dose distributions in high LET beams, for example to check hadron therapy treatment plans which comprise beams with different energies.

GEM: a dynamic tracking model for mesoscale eddies in the ocean

NASA Astrophysics Data System (ADS)

Li, Qiu-Yang; Sun, Liang; Lin, Sheng-Fu

2016-12-01

The Genealogical Evolution Model (GEM) presented here is an efficient logical model used to track dynamic evolution of mesoscale eddies in the ocean. It can distinguish between different dynamic processes (e.g., merging and splitting) within a dynamic evolution pattern, which is difficult to accomplish using other tracking methods. To this end, the GEM first uses a two-dimensional (2-D) similarity vector (i.e., a pair of ratios of overlap area between two eddies to the area of each eddy) rather than a scalar to measure the similarity between eddies, which effectively solves the "missing eddy" problem (temporarily lost eddy in tracking). Second, for tracking when an eddy splits, the GEM uses both "parent" (the original eddy) and "child" (eddy split from parent) and the dynamic processes are described as the birth and death of different generations. Additionally, a new look-ahead approach with selection rules effectively simplifies computation and recording. All of the computational steps are linear and do not include iteration. Given the pixel number of the target region L, the maximum number of eddies M, the number N of look-ahead time steps, and the total number of time steps T, the total computer time is O(LM(N + 1)T). The tracking of each eddy is very smooth because we require that the snapshots of each eddy on adjacent days overlap one another. Although eddy splitting or merging is ubiquitous in the ocean, they have different geographic distributions in the North Pacific Ocean. Both the merging and splitting rates of the eddies are high, especially at the western boundary, in currents and in "eddy deserts". The GEM is useful not only for satellite-based observational data, but also for numerical simulation outputs. It is potentially useful for studying dynamic processes in other related fields, e.g., the dynamics of cyclones in meteorology.

An improved model of the Earth's gravitational field: GEM-T1

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Lerch, F. J.; Christodoulidis, D. C.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Smith, D. E.; Klosko, S. M.; Martin, T. V.; Pavlis, E. C.

1987-01-01

Goddard Earth Model T1 (GEM-T1), which was developed from an analysis of direct satellite tracking observations, is the first in a new series of such models. GEM-T1 is complete to degree and order 36. It was developed using consistent reference parameters and extensive earth and ocean tidal models. It was simultaneously solved for gravitational and tidal terms, earth orientation parameters, and the orbital parameters of 580 individual satellite arcs. The solution used only satellite tracking data acquired on 17 different satellites and is predominantly based upon the precise laser data taken by third generation systems. In all, 800,000 observations were used. A major improvement in field accuracy was obtained. For marine geodetic applications, long wavelength geoidal modeling is twice as good as in earlier satellite-only GEM models. Orbit determination accuracy has also been substantially advanced over a wide range of satellites that have been tested.

SXR measurement and W transport survey using GEM tomographic system on WEST

NASA Astrophysics Data System (ADS)

Mazon, D.; Jardin, A.; Malard, P.; Chernyshova, M.; Coston, C.; Malard, P.; O'Mullane, M.; Czarski, T.; Malinowski, K.; Faisse, F.; Ferlay, F.; Verger, J. M.; Bec, A.; Larroque, S.; Kasprowicz, G.; Wojenski, A.; Pozniak, K.

2017-11-01

Measuring Soft X-Ray (SXR) radiation (0.1-20 keV) of fusion plasmas is a standard way of accessing valuable information on particle transport. Since heavy impurities like tungsten (W) could degrade plasma core performances and cause radiative collapses, it is necessary to develop new diagnostics to be able to monitor the impurity distribution in harsh fusion environments like ITER. A gaseous detector with energy discrimination would be a very good candidate for this purpose. The design and implementation of a new SXR diagnostic developed for the WEST project, based on a triple Gas Electron Multiplier (GEM) detector is presented. This detector works in photon counting mode and presents energy discrimination capabilities. The SXR system is composed of two 1D cameras (vertical and horizontal views respectively), located in the same poloidal cross-section to allow for tomographic reconstruction. An array (20 cm × 2 cm) consists of up to 128 detectors in front of a beryllium pinhole (equipped with a 1 mm diameter diaphragm) inserted at about 50 cm depth inside a cooled thimble in order to retrieve a wide plasma view. Acquisition of low energy spectrum is insured by a helium buffer installed between the pinhole and the detector. Complementary cooling systems (water) are used to maintain a constant temperature (25oC) inside the thimble. Finally a real-time automatic extraction system has been developed to protect the diagnostic during baking phases or any overheating unwanted events. Preliminary simulations of plasma emissivity and W distribution have been performed for WEST using a recently developed synthetic diagnostic coupled to a tomographic algorithm based on the minimum Fisher information (MFI) inversion method. First GEM acquisitions are presented as well as estimation of transport effect in presence of ICRH on W density reconstruction capabilities of the GEM.

2D dosimetry in a proton beam with a scintillating GEM detector

NASA Astrophysics Data System (ADS)

Seravalli, E.; de Boer, M. R.; Geurink, F.; Huizenga, J.; Kreuger, R.; Schippers, J. M.; van Eijk, C. W. E.

2009-06-01

A two-dimensional position-sensitive dosimetry system based on a scintillating gas detector is being developed for pre-treatment verification of dose distributions in particle therapy. The dosimetry system consists of a chamber filled with an Ar/CF4 scintillating gas mixture, inside which two gas electron multiplier (GEM) structures are mounted (Seravalli et al 2008b Med. Phys. Biol. 53 4651-65). Photons emitted by the excited Ar/CF4 gas molecules during the gas multiplication in the GEM holes are detected by a mirror-lens-CCD camera system. The intensity distribution of the measured light spot is proportional to the 2D dose distribution. In this work, we report on the characterization of the scintillating GEM detector in terms of those properties that are of particular importance in relative dose measurements, e.g. response reproducibility, dose dependence, dose rate dependence, spatial and time response, field size dependence, response uniformity. The experiments were performed in a 150 MeV proton beam. We found that the detector response is very stable for measurements performed in succession (σ = 0.6%) and its response reproducibility over 2 days is about 5%. The detector response was found to be linear with the dose in the range 0.05-19 Gy. No dose rate effects were observed between 1 and 16 Gy min-1 at the shallow depth of a water phantom and 2 and 38 Gy min-1 at the Bragg peak depth. No field size effects were observed in the range 120-3850 mm2. A signal rise and fall time of 2 µs was recorded and a spatial response of <=1 mm was measured.

Results of neutron irradiation of GEM detector for plasma radiation detection

NASA Astrophysics Data System (ADS)

Jednorog, S.; Bienkowska, B.; Chernyshova, M.; Łaszynska, E.; Prokopowicz, R.; Ziołkowski, A.

2015-09-01

The detecting devices dedicated for plasma monitoring will be exposed for massive fluxes of neutron, photons as well as other rays that are components of fusion reactions and their product interactions with plasma itself or surroundings. In result detecting module metallic components will be activated becoming a source of radiation. Moreover, electronics components could change their electronic properties. The prototype GEM detector constructed for monitoring soft X-ray radiation in ITER oriented tokamaks was used for plasma monitoring during experimental campaign on tokamak ASDEX Upgrade. After that it became a source of gamma radiation caused by neutrons. The present work contains description of detector activation in the laboratory conditions.

Modeling of serial data acquisition structure for GEM detector system in Matlab

NASA Astrophysics Data System (ADS)

Kolasinski, Piotr; Pozniak, Krzysztof T.; Czarski, Tomasz; Chernyshova, Maryna; Kasprowicz, Grzegorz; Krawczyk, Rafal D.; Wojenski, Andrzej; Zabolotny, Wojciech; Byszuk, Adrian

2016-09-01

This article presents method of modeling in Matlab hardware architecture dedicated for FPGA created by languages like VHDL or Verilog. Purposes of creating such type of model with its advantages and disadvantages are described. Rules presented in this article were exploited to create model of Serial Data Acquisition algorithm used in X-ray GEM detector system. Result were compared to real working model implemented in VHDL. After testing of basic structure, other two structures were modeled to see influence parameters of the structure on its behavior.

Multi-GEM Detectors in High Particle Fluxes

NASA Astrophysics Data System (ADS)

Thuiner, P.; Resnati, F.; Franchino, S.; Gonzalez Diaz, D.; Hall-Wilton, R.; Müller, H.; Oliveri, E.; Pfeiffer, D.; Ropelewski, L.; Van Stenis, M.; Streli, C.; Veenhof, R.

2018-02-01

Gaseous Electron Multipliers (GEM) are well known for stable operation at high particle fluxes. We present a study of the intrinsic limits of GEMdetectors when exposed to very high particle fluxes of the order of MHz/mm2. We give an interpretation to the variations of the effective gain, which, as a function of the particle flux, first increases and then decreases. We also discuss the reduction of the ion back-flow with increasing flux. We present measurements and simulations of a triple GEM detector, describing its behaviour in terms of accumulation of positive ions that results in changes of the transfer fields and the amplification fields. The behaviour is expected to be common to all multi-stage amplification devices where the efficiency of transferring the electrons from one stage to the next one is not 100%.

PLC-controlled cryostats for the BlackGEM and MeerLICHT detectors

NASA Astrophysics Data System (ADS)

Raskin, Gert; Morren, Johan; Pessemier, Wim; Bloemen, Steven; Klein-Wolt, Marc; Roelfsema, Ronald; Groot, Paul; Aerts, Conny

2016-08-01

BlackGEM is an array of telescopes, currently under development at the Radboud University Nijmegen and at NOVA (Netherlands Research School for Astronomy). It targets the detection of the optical counterparts of gravitational waves. The first three BlackGEM telescopes are planned to be installed in 2018 at the La Silla observatory (Chile). A single prototype telescope, named MeerLICHT, will already be commissioned early 2017 in Sutherland (South Africa) to provide an optical complement for the MeerKAT radio array. The BlackGEM array consists of, initially, a set of three robotic 65-cm wide-field telescopes. Each telescope is equipped with a single STA1600 CCD detector with 10.5k x 10.5k 9-micron pixels that covers a 2.7 square degrees field of view. The cryostats for housing these detectors are developed and built at the KU Leuven University (Belgium). The operational model of BlackGEM requires long periods of reliable hands-off operation. Therefore, we designed the cryostats for long vacuum hold time and we make use of a closed-cycle cooling system, based on Polycold PCC Joule-Thomson coolers. A single programmable logic controller (PLC) controls the cryogenic systems of several BlackGEM telescopes simultaneously, resulting in a highly reliable, cost-efficient and maintenance-friendly system. PLC-based cryostat control offers some distinct advantages, especially for a robotic facility. Apart of temperature monitoring and control, the PLC also monitors the vacuum quality, the power supply and the status of the PCC coolers (compressor power consumption and temperature, pressure in the gas lines, etc.). Furthermore, it provides an alarming system and safe and reproducible procedures for automatic cool down and warm up. The communication between PLC and higher-level software takes place via the OPC-UA protocol, offering a simple to implement, yet very powerful interface. Finally, a touch-panel display on the PLC provides the operator with a user-friendly and robust technical interface. In this contribution, we present the design of the BlackGEM cryostats and of the PLC-based control system.

Ethernet based data logger for gaseous detectors

NASA Astrophysics Data System (ADS)

Swain, S.; Sahu, P. K.; Sahu, S. K.

2018-05-01

A data logger is designed to monitor and record ambient parameters such as temperature, pressure and relative humidity along with gas flow rate as a function of time. These parameters are required for understanding the characteristics of gas-filled detectors such as Gas Electron Multiplier (GEM) and Multi-Wire Proportional Counter (MWPC). The data logger has different microcontrollers and has been interfaced to an ethernet port with a local LCD unit for displaying all measured parameters. In this article, the explanation of the data logger design, hardware, and software description of the master microcontroller and the DAQ system along with LabVIEW interface client program have been presented. We have implemented this device with GEM detector and displayed few preliminary results as a function of above parameters.

Cosmic Ray Tests of Gas Electron Multipliers

NASA Astrophysics Data System (ADS)

Harris, Letrell; Kohl, Michael; Super Bigbite Spectrometer Collaboration; MUSE Collaboration; Hampton University Collaboration; DarkLight Collaboration

2017-09-01

The Super Bigbite Spectrometer (SBS) collaboration at Jefferson Laboratory (Jlab) is conducting an experimental program to measure the elastic form factors of nucleons. In association with Jlab, SBS Gas Electron Multipliers (GEMs) have been constructed by the University of Virginia (back trackers) and INFN in Italy (front trackers). The SBS GEMs measuring 40 × 150 cm2 (front trackers) and 60 × 200 cm2 (back trackers) in surface area are in the process of being conditioned and analyzed for tracking efficiency using cosmic rays in a clean room test lab before further assembly in the fall. These GEMs will be used to track the path of particles scattered off nuclear targets. Scintillators are placed both above and below GEM stacks to trigger a readout. In addition, Hampton University has also constructed a set of 10 × 10 cm2 GEMs originally for the OLYMPUS experiment at DESY in Germany, which are now being used for both the MUSE experiment at Paul Scherrer Institute (PSI) in Switzerland and the DarkLight experiment at Jlab's Low Energy Recirculatory Facility (LERF), where they are in the process of being characterized with cosmic rays. Jefferson Laboratory. This work has been supported by Jefferson Laboratory.

Research on a Neutron Detector With a Boron-Lined Honeycomb Neutron Converter

NASA Astrophysics Data System (ADS)

Fang, Zhujun; Yang, Yigang; Li, Yulan; Zhang, Zhi; Wang, Xuewu

2017-04-01

A new design of the boron-lined gaseous neutron detector composed of a boron-lined honeycomb neutron converter and an electron multiplier is proposed in this paper. The motivation for this research was to decrease the manufacturing difficulty and improve the robustness of the boron-lined gaseous neutron detector. The numerous anode wires in the traditional designs were removed, and the gas electron multiplier (GEM) was used as the electron multiplier. To drive the ionized electrons produced inside the honeycomb structure out to the incident surface of the GEM, a drift electric field was applied inside the holes of the honeycomb structure. The design principles of this detector were discussed. Geant4, Maxwell11, and Garfield9 were used to estimate the neutron absorption efficiency and the electron migration process. A prototype detector was constructed and experimentally evaluated. Both the simulation and experimental results indicate that this detector has the potential to be used in the applications of small angle neutron scattering for scientific research, and to replace the currently used 3He detectors, which have the trouble of very limited supply of 3He gas.

GEM detectors development for radiation environment: neutron tests and simulations

NASA Astrophysics Data System (ADS)

Chernyshova, Maryna; Jednoróg, Sławomir; Malinowski, Karol; Czarski, Tomasz; Ziółkowski, Adam; Bieńkowska, Barbara; Prokopowicz, Rafał; Łaszyńska, Ewa; Kowalska-Strzeciwilk, Ewa; Poźniak, Krzysztof T.; Kasprowicz, Grzegorz; Zabołotny, Wojciech; Wojeński, Andrzej; Krawczyk, Rafał D.; Linczuk, Paweł; Potrykus, Paweł; Bajdel, Barcel

2016-09-01

One of the requests from the ongoing ITER-Like Wall Project is to have diagnostics for Soft X-Ray (SXR) monitoring in tokamak. Such diagnostics should be focused on tungsten emission measurements, as an increased attention is currently paid to tungsten due to a fact that it became a main candidate for the plasma facing material in ITER and future fusion reactor. In addition, such diagnostics should be able to withstand harsh radiation environment at tokamak during its operation. The presented work is related to the development of such diagnostics based on Gas Electron Multiplier (GEM) technology. More specifically, an influence of neutron radiation on performance of the GEM detectors is studied both experimentally and through computer simulations. The neutron induced radioactivity (after neutron source exposure) was found to be not pronounced comparing to an impact of other secondary neutron reaction products (during the exposure).

Introducing parallelism to histogramming functions for GEM systems

NASA Astrophysics Data System (ADS)

Krawczyk, Rafał D.; Czarski, Tomasz; Kolasinski, Piotr; Pozniak, Krzysztof T.; Linczuk, Maciej; Byszuk, Adrian; Chernyshova, Maryna; Juszczyk, Bartlomiej; Kasprowicz, Grzegorz; Wojenski, Andrzej; Zabolotny, Wojciech

2015-09-01

This article is an assessment of potential parallelization of histogramming algorithms in GEM detector system. Histogramming and preprocessing algorithms in MATLAB were analyzed with regard to adding parallelism. Preliminary implementation of parallel strip histogramming resulted in speedup. Analysis of algorithms parallelizability is presented. Overview of potential hardware and software support to implement parallel algorithm is discussed.

On algorithmic optimization of histogramming functions for GEM systems

NASA Astrophysics Data System (ADS)

Krawczyk, Rafał D.; Czarski, Tomasz; Kolasinski, Piotr; Poźniak, Krzysztof T.; Linczuk, Maciej; Byszuk, Adrian; Chernyshova, Maryna; Juszczyk, Bartlomiej; Kasprowicz, Grzegorz; Wojenski, Andrzej; Zabolotny, Wojciech

2015-09-01

This article concerns optimization methods for data analysis for the X-ray GEM detector system. The offline analysis of collected samples was optimized for MATLAB computations. Compiled functions in C language were used with MEX library. Significant speedup was received for both ordering-preprocessing and for histogramming of samples. Utilized techniques with obtained results are presented.

Large size GEM for Super Bigbite Spectrometer (SBS) polarimeter for Hall A 12GeV program at JLab

DOE PAGES

Gnanvo, Kondo; Liyanage, Nilanga; Nelyubin, Vladimir; ...

2015-05-01

We report on the R&D effort in the design and construction of a large size GEM chamber for the Proton Polarimeter of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS Polarimeter trackers consist of two sets of four large chambers of size 200 cm x 60 cm 2. Each chamber is a vertical stack of four GEM modules with an active area of 60 cm x 50 cm. We have built and tested several GEM modules and we describe in this paper the design and construction of the final GEM as wellmore » as the preliminary results on performances from tests carried out in our detector lab and with test beams at (Fermilab).« less

Development of GEM gas detectors for X-ray crystal spectrometry

NASA Astrophysics Data System (ADS)

Chernyshova, M.; Czarski, T.; Dominik, W.; Jakubowska, K.; Rzadkiewicz, J.; Scholz, M.; Pozniak, K.; Kasprowicz, G.; Zabolotny, W.

2014-03-01

Two Triple Gas Electron Multiplier (Triple-GEM) detectors were developed for high-resolution X-ray spectroscopy measurements for tokamak plasma to serve as plasma evolution monitoring in soft X-ray region (SXR). They provide energy resolved fast dynamic plasma radiation imaging in the SXR with 0.1 kHz frequency. Detectors were designed and constructed for continuous data-flow precise energy and position measurement of plasma radiation emitted by metal impurities, W46+ and Ni26+ ions, at 2.4 keV and 7.8 keV photon energies, respectively. High counting rate capability of the detecting units has been achieved with good position resolution. This article presents results of the laboratory and tokamak experiments together with the system performance under irradiation by photon flux from the plasma core.

Gas scintillation glass GEM detector for high-resolution X-ray imaging and CT

NASA Astrophysics Data System (ADS)

Fujiwara, T.; Mitsuya, Y.; Fushie, T.; Murata, K.; Kawamura, A.; Koishikawa, A.; Toyokawa, H.; Takahashi, H.

2017-04-01

A high-spatial-resolution X-ray-imaging gaseous detector has been developed with a single high-gas-gain glass gas electron multiplier (G-GEM), scintillation gas, and optical camera. High-resolution X-ray imaging of soft elements is performed with a spatial resolution of 281 μm rms and an effective area of 100×100 mm. In addition, high-resolution X-ray 3D computed tomography (CT) is successfully demonstrated with the gaseous detector. It shows high sensitivity to low-energy X-rays, which results in high-contrast radiographs of objects containing elements with low atomic numbers. In addition, the high yield of scintillation light enables fast X-ray imaging, which is an advantage for constructing CT images with low-energy X-rays.

Properties of the Flight Model Gas Electron Multiplier for the GEMS Mission

NASA Technical Reports Server (NTRS)

Takeuchi, Yoko; Kitaguchi, Takao; Hayato, Asami; Tamagawa, Toru; Iwakiri, Wataru; Asami, Fumi; Yoshikawa, Akifumi; Kaneko, Kenta; Enoto, Teruaki; Black, Kevin;

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The GEM collaboration was formed in June 1991 to develop a major detector for the SSC. The primary physics objectives of GEM are those central to the motivation for the SSC, to study high p{sub T} physics - exemplified by the search for Higgs bosons - and to search for new physics beyond the standard model. The authors present in this Technical Design Report (TDR) a detector with broad capabilities for the discovery and subsequent study of electroweak symmetry breaking, the origin of mass and flavor, and other physics requiring precise measurements of gammas, electrons, and muons - hence themore » name, GEM. In addition, as a design goal, they have taken care to provide the robustness needed to do the physics that requires high luminosity. Finally, good coverage and hermeticity allow the detection of missing transverse energy, E{sub T}. The GEM design emphasizes clean identification and high resolution measurement of the primary physics signatures for high p{sub T} physics. The approach is to make precise energy measurements that maximize the sensitivity to rare narrow resonances, to detect the elementary interaction products (quarks, leptons, and photons), and to build in the features required to reduce backgrounds.« less

Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search

NASA Astrophysics Data System (ADS)

Monteiro, C. M. B.; Fernandes, L. M. P.; Veloso, J. F. C. A.; Oliveira, C. A. B.; dos Santos, J. M. F.

2012-07-01

The search for alternatives to PMTs as photosensors in optical TPCs for rare event detection has significantly increased in the last few years. In particular, in view of the next generation large volume detectors, the use of photosensors with lower natural radioactivity, such as large area APDs or GM-APDs, with the additional possibility of sparse surface coverage, triggered the intense study of secondary scintillation production in micropattern electron multipliers, such as GEMs and THGEMs, as alternatives to the commonly used uniform electric field region between two parallel meshes. The much higher scintillation output obtained from the electron avalanches in such microstructures presents an advantage in those situations. The accurate knowledge of the amount of such scintillation is important for correct detector simulation and optimization. It will also serve as a benchmark for software tools developed and/or under development for the calculation of the amount of such scintillation.The secondary scintillation yield, or electroluminescence yield, in the electron avalanches of GEMs and THGEMs operating in gaseous xenon and argon has been determined for different gas pressures. At 1 bar, THGEMs deliver electroluminescence yields that are more than one order of magnitude higher when compared to those achieved in GEMs and two orders of magnitude when compared to those achieved in a uniform field gap. The THGEM electroluminescence yield presents a faster decrease with pressure when comparing to the GEM electroluminescence yield, reaching similar values to what is achieved in GEMs for xenon pressures of 2.5 bar, but still one order of magnitude higher than that produced in a uniform field gap. Another exception is the GEM operating in argon, which presents an electroluminescence yield similar to that produced in a uniform electric field gap, while the THGEM achieves yields that are more than one order of magnitude higher.

Evaluation of advanced geopotential models for operational orbit determination

NASA Technical Reports Server (NTRS)

Radomski, M. S.; Davis, B. E.; Samii, M. V.; Engel, C. J.; Doll, C. E.

1988-01-01

To meet future orbit determination accuracy requirements for different NASA projects, analyses are performed using Tracking and Data Relay Satellite System (TDRSS) tracking measurements and orbit determination improvements in areas such as the modeling of the Earth's gravitational field. Current operational requirements are satisfied using the Goddard Earth Model-9 (GEM-9) geopotential model with the harmonic expansion truncated at order and degree 21 (21-by-21). This study evaluates the performance of 36-by-36 geopotential models, such as the GEM-10B and Preliminary Goddard Solution-3117 (PGS-3117) models. The Earth Radiation Budget Satellite (ERBS) and LANDSAT-5 are the spacecraft considered in this study.

Automatic tracking of dynamical evolutions of oceanic mesoscale eddies with satellite observation data

NASA Astrophysics Data System (ADS)

Sun, Liang; Li, Qiu-Yang

2017-04-01

The oceanic mesoscale eddies play a major role in ocean climate system. To analyse spatiotemporal dynamics of oceanic mesoscale eddies, the Genealogical Evolution Model (GEM) based on satellite data is developed, which is an efficient logical model used to track dynamic evolution of mesoscale eddies in the ocean. It can distinguish different dynamic processes (e.g., merging and splitting) within a dynamic evolution pattern, which is difficult to accomplish using other tracking methods. To this end, a mononuclear eddy detection method was firstly developed with simple segmentation strategies, e.g. watershed algorithm. The algorithm is very fast by searching the steepest descent path. Second, the GEM uses a two-dimensional similarity vector (i.e. a pair of ratios of overlap area between two eddies to the area of each eddy) rather than a scalar to measure the similarity between eddies, which effectively solves the ''missing eddy" problem (temporarily lost eddy in tracking). Third, for tracking when an eddy splits, GEM uses both "parent" (the original eddy) and "child" (eddy split from parent) and the dynamic processes are described as birth and death of different generations. Additionally, a new look-ahead approach with selection rules effectively simplifies computation and recording. All of the computational steps are linear and do not include iteration. Given the pixel number of the target region L, the maximum number of eddies M, the number N of look-ahead time steps, and the total number of time steps T, the total computer time is O (LM(N+1)T). The tracking of each eddy is very smooth because we require that the snapshots of each eddy on adjacent days overlap one another. Although eddy splitting or merging is ubiquitous in the ocean, they have different geographic distribution in the Northern Pacific Ocean. Both the merging and splitting rates of the eddies are high, especially at the western boundary, in currents and in "eddy deserts". GEM is useful not only for satellite-based observational data but also for numerical simulation outputs. It is potentially useful for studying dynamic processes in other related fields, e.g., the dynamics of cyclones in meteorology.

Rate and Gain Limitations of MSGC's and MGC's Combined with GEM and other Preamplification Structures

NASA Technical Reports Server (NTRS)

Fonte, P.; Peskov, V.; Ramsey, B. D.

1998-01-01

We have studied the rate and gain limits of diamond-coated Microstrip Gas Counters (MSGC's) and Micro-Gap Counters (MGC's) when combined with various preamplification structures: Gas Electron Multiplier (GEM), Parallel-Plate Avalanche Chamber (PPAC) or a MICROMEGAS-type structure. Measurements were done both with X rays and alpha particles with various detector geometries and in different gas mixtures at pressures from 0.05 to 10 atm. The results obtained varied significantly with detector design, gas mixture and pressure, but some general features can be identified. We found that in all cases, bare MSGC'S, MGC'S, PPAC's and MICROMEGAS, the maximum achievable gain drops with rate. The addition of preamplification structures significantly increases the gain of MSGC's and MGC'S, but this gain is still rate dependent. There would seem to be a general rate-dependent effect governing the usable gain of all these detectors. We speculate on possible mechanisms for this effect, and identify a safe, spark-free, operation zone for each system (detector + preamplification structure) in the rate-gain coordinate plane.

Experimental High Energy Physics Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hohlmann, Marcus

This final report summarizes activities of the Florida Tech High Energy Physics group supported by DOE under grant #DE-SC0008024 during the period June 2012 – March 2015. We focused on one of the main HEP research thrusts at the Energy Frontier by participating in the CMS experiment. We were exploiting the tremendous physics opportunities at the Large Hadron Collider (LHC) and prepared for physics at its planned extension, the High-Luminosity LHC. The effort comprised a physics component with analysis of data from the first LHC run and contributions to the CMS Phase-2 upgrades in the muon endcap system (EMU) formore » the High-Luminosity LHC. The emphasis of our hardware work was the development of large-area Gas Electron Multipliers (GEMs) for the CMS forward muon upgrade. We built a production and testing site for such detectors at Florida Tech to complement future chamber production at CERN. The first full-scale CMS GE1/1 chamber prototype ever built outside of CERN was constructed at Florida Tech in summer 2013. We conducted two beam tests with GEM prototype chambers at CERN in 2012 and at FNAL in 2013 and reported the results at conferences and in publications. Principal Investigator Hohlmann served as chair of the collaboration board of the CMS GEM collaboration and as co-coordinator of the GEM detector working group. He edited and authored sections of the detector chapter of the Technical Design Report (TDR) for the GEM muon upgrade, which was approved by the LHCC and the CERN Research Board in 2015. During the course of the TDR approval process, the GEM project was also established as an official subsystem of the muon system by the CMS muon institution board. On the physics side, graduate student Kalakhety performed a Z' search in the dimuon channel with the 2011 and 2012 CMS datasets that utilized 20.6 fb⁻¹ of p-p collisions at √s = 8 TeV. For the dimuon channel alone, the 95% CL lower limits obtained on the mass of a Z' resonance are 2770 GeV for a Z' with the same standard-model couplings as the Z boson. Our student team operated a Tier-3 cluster on the Open Science Grid (OSG) to support local CMS physics analysis and remote OSG activity. As a service to the HEP community, Hohlmann participated in the Snowmass effort over the course of 2013. Specifically, he acted as a liaison for gaseous detectors between the Instrumentation Frontier and the Energy Frontier and contributed to five papers and reports submitted to the summer study.« less

FPGA-Based X-Ray Detection and Measurement for an X-Ray Polarimeter

NASA Technical Reports Server (NTRS)

Gregory, Kyle; Hill, Joanne; Black, Kevin; Baumgartner, Wayne

2013-01-01

This technology enables detection and measurement of x-rays in an x-ray polarimeter using a field-programmable gate array (FPGA). The technology was developed for the Gravitational and Extreme Magnetism Small Explorer (GEMS) mission. It performs precision energy and timing measurements, as well as rejection of non-x-ray events. It enables the GEMS polarimeter to detect precisely when an event has taken place so that additional measurements can be made. The technology also enables this function to be performed in an FPGA using limited resources so that mass and power can be minimized while reliability for a space application is maximized and precise real-time operation is achieved. This design requires a low-noise, charge-sensitive preamplifier; a highspeed analog to digital converter (ADC); and an x-ray detector with a cathode terminal. It functions by computing a sum of differences for time-samples whose difference exceeds a programmable threshold. A state machine advances through states as a programmable number of consecutive samples exceeds or fails to exceed this threshold. The pulse height is recorded as the accumulated sum. The track length is also measured based on the time from the start to the end of accumulation. For track lengths longer than a certain length, the algorithm estimates the barycenter of charge deposit by comparing the accumulator value at the midpoint to the final accumulator value. The design also employs a number of techniques for rejecting background events. This innovation enables the function to be performed in space where it can operate autonomously with a rapid response time. This implementation combines advantages of computing system-based approaches with those of pure analog approaches. The result is an implementation that is highly reliable, performs in real-time, rejects background events, and consumes minimal power.

Gaseous electron multiplier-based soft x-ray plasma diagnostics development: Preliminary tests at ASDEX Upgrade.

PubMed

Chernyshova, M; Malinowski, K; Czarski, T; Wojeński, A; Vezinet, D; Poźniak, K T; Kasprowicz, G; Mazon, D; Jardin, A; Herrmann, A; Kowalska-Strzęciwilk, E; Krawczyk, R; Kolasiński, P; Zabołotny, W; Zienkiewicz, P

2016-11-01

A Gaseous Electron Multiplier (GEM)-based detector is being developed for soft X-ray diagnostics on tokamaks. Its main goal is to facilitate transport studies of impurities like tungsten. Such studies are very relevant to ITER, where the excessive accumulation of impurities in the plasma core should be avoided. This contribution provides details of the preliminary tests at ASDEX Upgrade (AUG) with a focus on the most important aspects for detector operation in harsh radiation environment. It was shown that both spatially and spectrally resolved data could be collected, in a reasonable agreement with other AUG diagnostics. Contributions to the GEM signal include also hard X-rays, gammas, and neutrons. First simulations of the effect of high-energy photons have helped understanding these contributions.

Gaseous electron multiplier-based soft x-ray plasma diagnostics development: Preliminary tests at ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Chernyshova, M.; Malinowski, K.; Czarski, T.; Wojeński, A.; Vezinet, D.; Poźniak, K. T.; Kasprowicz, G.; Mazon, D.; Jardin, A.; Herrmann, A.; Kowalska-Strzeciwilk, E.; Krawczyk, R.; Kolasiński, P.; Zabołotny, W.; Zienkiewicz, P.

2016-11-01

A Gaseous Electron Multiplier (GEM)-based detector is being developed for soft X-ray diagnostics on tokamaks. Its main goal is to facilitate transport studies of impurities like tungsten. Such studies are very relevant to ITER, where the excessive accumulation of impurities in the plasma core should be avoided. This contribution provides details of the preliminary tests at ASDEX Upgrade (AUG) with a focus on the most important aspects for detector operation in harsh radiation environment. It was shown that both spatially and spectrally resolved data could be collected, in a reasonable agreement with other AUG diagnostics. Contributions to the GEM signal include also hard X-rays, gammas, and neutrons. First simulations of the effect of high-energy photons have helped understanding these contributions.

Conceptual design and development of GEM based detecting system for tomographic tungsten focused transport monitoring

NASA Astrophysics Data System (ADS)

Chernyshova, M.; Czarski, T.; Malinowski, K.; Kowalska-Strzęciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Kolasiński, P.; Mazon, D.; Malard, P.

2015-10-01

Implementing tungsten as a plasma facing material in ITER and future fusion reactors will require effective monitoring of not just its level in the plasma but also its distribution. That can be successfully achieved using detectors based on Gas Electron Multiplier (GEM) technology. This work presents the conceptual design of the detecting unit for poloidal tomography to be tested at the WEST project tokamak. The current stage of the development is discussed covering aspects which include detector's spatial dimensions, gas mixtures, window materials and arrangements inside and outside the tokamak ports, details of detector's structure itself and details of the detecting module electronics. It is expected that the detecting unit under development, when implemented, will add to the safe operation of tokamak bringing the creation of sustainable nuclear fusion reactors a step closer. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

Study of a nTHGEM-based thermal neutron detector

NASA Astrophysics Data System (ADS)

Li, Ke; Zhou, Jian-Rong; Wang, Xiao-Dong; Xiong, Tao; Zhang, Ying; Xie, Yu-Guang; Zhou, Liang; Xu, Hong; Yang, Gui-An; Wang, Yan-Feng; Wang, Yan; Wu, Jin-Jie; Sun, Zhi-Jia; Hu, Bi-Tao

2016-07-01

With new generation neutron sources, traditional neutron detectors cannot satisfy the demands of the applications, especially under high flux. Furthermore, facing the global crisis in 3He gas supply, research on new types of neutron detector as an alternative to 3He is a research hotspot in the field of particle detection. GEM (Gaseous Electron Multiplier) neutron detectors have high counting rate, good spatial and time resolution, and could be one future direction of the development of neutron detectors. In this paper, the physical process of neutron detection is simulated with Geant4 code, studying the relations between thermal conversion efficiency, boron thickness and number of boron layers. Due to the special characteristics of neutron detection, we have developed a novel type of special ceramic nTHGEM (neutron THick GEM) for neutron detection. The performance of the nTHGEM working in different Ar/CO2 mixtures is presented, including measurements of the gain and the count rate plateau using a copper target X-ray source. A detector with a single nTHGEM has been tested for 2-D imaging using a 252Cf neutron source. The key parameters of the performance of the nTHGEM detector have been obtained, providing necessary experimental data as a reference for further research on this detector. Supported by National Natural Science Foundation of China (11127508, 11175199, 11205253, 11405191), Key Laboratory of Neutron Physics, CAEP (2013DB06, 2013BB04) and CAS (YZ201512)

Detectors for MUSE

NASA Astrophysics Data System (ADS)

Hirschman, Jack; Muon Scattering Experiment (MUSE) Collaboration

2017-09-01

Until recently, it was thought that the proton radius was known with an uncertainty of 1%. However, experiments carried-out at the Paul Scherrer Institute (PSI) involving muonic hydrogen yielded a radius 4% smaller with an uncertainty of .1%, a 7.9 σ inconsistency. This problem of properly measuring the radius now requires new and different measurements. The Muon Scattering Experiment (MUSE) will thus be the first to utilize elastic muon scattering with sufficient precision to address the proton radius measurement. MUSE will run in PSI's PiM1 beamline, using a stack of GEM chambers and thin scintillation detectors to identify and track the beam particle species in this mixed e, pi, mu beam. Scattered particles will be measured in two arms with ten layers of Straw Tube Tracking (STT) detectors and a double plastic scintillator wall for timing of and triggering on scattered particles. The STT chambers will employ the anti-Proton Annihilations at Darmstadt (PANDA) design. Each straw consists of a thin wire with high voltage surrounded by an aluminized Mylar tube inflated with a mix of Argon and Carbon Dioxide, the ratio of which is important for optimal operation. The Argon gas, ionized by incoming charged particles, releases electrons which attract to the central wire. The CO2 acts as a quencher, taking-up electrons to prevent an unstable avalanche effect. This project will investigate the effects of altering the gas mixture in the STTs on signal size and timing. This material is based upon work supported by the National Science Foundation under Grant No. OISE-1358175, PHY-1614850, and PHY-1614938. Thank you to the teams at HUJI and PSI, in particular, Dr. G. Ron, Dr. T. Rostomyan, Dr. K. Dieters, and D. Cohen.

Calibrating an optical scanner for quality assurance of large area radiation detectors

NASA Astrophysics Data System (ADS)

Karadzhinova, A.; Hildén, T.; Berdova, M.; Lauhakangas, R.; Heino, J.; Tuominen, E.; Franssila, S.; Hæggström, E.; Kassamakov, I.

2014-11-01

A gas electron multiplier (GEM) is a particle detector used in high-energy physics. Its main component is a thin copper-polymer-copper sandwich that carries Ø =70  ±  5 µm holes. Quality assurance (QA) is needed to guarantee both long operating life and reading fidelity of the GEM. Absence of layer defects and conformity of the holes to specifications is important. Both hole size and shape influence the detector’s gas multiplication factor and hence affect the collected data. For the scanner the required lateral measurement tolerance is ± 5 µm. We calibrated a high aspect ratio optical scanning system (OSS) to allow ensuring the quality of large GEM foils. For the calibration we microfabricated transfer standards, which were imaged with the OSS and which were compared to corresponding scanning electron microscopy (SEM) images. The calibration fulfilled the ISO/IEC 17025 and UKAS M3003 requirements: the calibration factor was 1.01  ±  0.01, determined at 95% confidence level across a 950  ×  950 mm2 area. The proposed large-scale scanning technique can potentially be valuable in other microfabricated products too.

On line separation of overlapped signals from multi-time photons for the GEM-based detection system

NASA Astrophysics Data System (ADS)

Czarski, T.; Pozniak, K. T.; Chernyshova, M.; Malinowski, K.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zabolotny, W.

2015-09-01

The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector for high-resolution X-ray diagnostics of magnetic confinement fusion plasmas. Multi-channel measurement system and serial data acquisition for X-ray energy and position recognition is described. Fundamental characteristics are presented for two dimensional detector structure. Typical signals of ADC - Analog to Digital Converter are considered for charge value and position estimation. Coinciding signals for high flux radiation cause the problem for cluster charge identification. The amplifier with shaper determines time characteristics and limits the pulses frequency. Separation of coincided signals was introduced and verified for simulation experiments. On line separation of overlapped signals was implemented applying the FPGA technology with relatively simple firmware procedure. Representative results for reconstruction of coinciding signals are demonstrated.

Gaseous electron multiplier-based soft x-ray plasma diagnostics development: Preliminary tests at ASDEX Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chernyshova, M., E-mail: maryna.chernyshova@ipplm.pl; Malinowski, K.; Czarski, T.

2016-11-15

A Gaseous Electron Multiplier (GEM)-based detector is being developed for soft X-ray diagnostics on tokamaks. Its main goal is to facilitate transport studies of impurities like tungsten. Such studies are very relevant to ITER, where the excessive accumulation of impurities in the plasma core should be avoided. This contribution provides details of the preliminary tests at ASDEX Upgrade (AUG) with a focus on the most important aspects for detector operation in harsh radiation environment. It was shown that both spatially and spectrally resolved data could be collected, in a reasonable agreement with other AUG diagnostics. Contributions to the GEM signalmore » include also hard X-rays, gammas, and neutrons. First simulations of the effect of high-energy photons have helped understanding these contributions.« less

The ALICE TPC Upgrad

NASA Astrophysics Data System (ADS)

Castro, Andrew; Alice-Usa Collaboration; Alice-Tpc Collaboration

2017-09-01

The Time Projection Chamber (TPC) currently used for ALICE (A Large Ion Collider Experiment at CERN) is a gaseous tracking detector used to study both proton-proton and heavy-ion collisions at the Large Hadron Collider (LHC) In order to accommodate the higher luminosit collisions planned for the LHC Run-3 starting in 2021, the ALICE-TPC will undergo a major upgrade during the next LHC shut down. The TPC is limited to a read out of 1000 Hz in minimum bias events due to the intrinsic dead time associated with back ion flow in the multi wire proportional chambers (MWPC) in the TPC. The TPC upgrade will handle the increase in event readout to 50 kHz for heavy ion minimum bias triggered events expected with the Run-3 luminosity by switching the MWPCs to a stack of four Gaseous Electron Multiplier (GEM) foils. The GEM layers will combine different hole pitches to reduce the dead time while maintaining the current spatial and energy resolution of the existing TPC. Undertaking the upgrade of the TPC represents a massive endeavor in terms of design, production, construction, quality assurance, and installation, thus the upgrade is coordinated over a number of institutes worldwide. The talk will go over the physics motivation for the upgrade, the ALICE-USA contribution to the construction of Inner Read Out Chambers IROCs, and QA from the first chambers built in the U.S

Development of near infrared spectrometer for gem materials study

NASA Astrophysics Data System (ADS)

Jindata, W.; Meesiri, W.; Wongkokua, W.

2015-07-01

Most of gem materials can be characterized by infrared absorption spectroscopy. Normally, mid infrared absorption technique has been applied for investigating fundamental vibrational modes. However, for some gem materials, such as tourmaline, NIR is a better choice due to differentiation. Most commercial NIR spectrometers employ complicated dispersive grating or Fourier transform techniques. In this work, we developed a filter type NIR spectrometer with the availability of high efficiency and low-cost narrow bandpass NIR interference filters to be taught in a physics laboratory. The instrument was designed for transmission-mode configuration. A 50W halogen lamp was used as NIR source. There were fourteen NIR filters mounted on a rotatory wheel for wavelength selection ranging from 1000-1650 nm with steps of 50 nm. A 1.0 mm diameter of InGaAs photodiode was used as the detector for the spectrometer. Hence, transparent gem materials can be used as samples for experiment. Student can learn vibrational absorption spectroscopy as well as Beer-Lambert law from the development of this instrument.

High-Sensitivity X-ray Polarimetry with Amorphous Silicon Active-Matrix Pixel Proportional Counters

NASA Technical Reports Server (NTRS)

Black, J. K.; Deines-Jones, P.; Jahoda, K.; Ready, S. E.; Street, R. A.

2003-01-01

Photoelectric X-ray polarimeters based on pixel micropattern gas detectors (MPGDs) offer order-of-magnitude improvement in sensitivity over more traditional techniques based on X-ray scattering. This new technique places some of the most interesting astronomical observations within reach of even a small, dedicated mission. The most sensitive instrument would be a photoelectric polarimeter at the focus of 2 a very large mirror, such as the planned XEUS. Our efforts are focused on a smaller pathfinder mission, which would achieve its greatest sensitivity with large-area, low-background, collimated polarimeters. We have recently demonstrated a MPGD polarimeter using amorphous silicon thin-film transistor (TFT) readout suitable for the focal plane of an X-ray telescope. All the technologies used in the demonstration polarimeter are scalable to the areas required for a high-sensitivity collimated polarimeter. Leywords: X-ray polarimetry, particle tracking, proportional counter, GEM, pixel readout

TCPD: A micropattern photon detector hybrid for RICH applications

NASA Astrophysics Data System (ADS)

Hamar, G.; Varga, D.

2017-03-01

A micropattern and wire chamber hybrid has been constructed for UV photon detection, and its performance evaluated. It is revealed that such combination retains some key advantages of both the Thick-GEM primary and CCC secondary amplification stages, and results in a high gain gaseous photon detector with outstanding stability. Key features such as MIP suppression, detection efficiency and photon cluster size are discussed. The capability of the detector for UV photon detection has been established and proven with Cherenkov photons in particle beam tests.

A 32-channel front-end ASIC for GEM detectors used in beam monitoring applications

NASA Astrophysics Data System (ADS)

Ciciriello, F.; Altieri, P. R.; Corsi, F.; De Robertis, G.; Felici, G.; Loddo, F.; Lorusso, L.; Marzocca, C.; Matarrese, G.; Ranieri, A.; Stamerra, A.

2017-11-01

A multichannel, mixed-signal, front-end ASIC for GEM detectors, intended for beam monitoring in hadron therapy applications, has been designed and prototyped in a standard 0.35 μm CMOS technology. The analog channels are based on the classic CSA + shaper processing chain, followed by a peak detector which can work as an analog memory, to simplifiy the analog-to-digital conversion of the peak voltage of the output pulse, proportional to the energy of the detected event. The available hardware resources include an 8-bit A/D converter and a standard-cell digital part, which manages the read-out procedure, in sparse or serial mode. The ASIC is self-triggered and transfers energy and address data to the external DAQ via a fast 100 MHz LVDS link. Preliminary characterization results show that the non-linearity error is limited to 5% for a maximum input charge of about 70 fC, the measured ENC is about 1400e- and the time jitter of the trigger signal generated in response to an injected charge of 60 fC is close to 200 ps.

Identifying the Source of Gem Diamonds: Requirements for a Certification System

NASA Astrophysics Data System (ADS)

Shigley, J. E.

2002-05-01

Recent civil conflicts in several countries, in which profits from the sales of gem diamonds have supported the rival factions, have forced the jewelry industry to confront the need to certify the geographic sources of gem diamonds. The goals of this program are to prohibit the sale of so-called "conflict diamonds", and to prevent the loss of consumer confidence. Efforts to identify unique characteristics of gem diamonds have been hampered so far by the absence of chemical or physical features that are diagnostic of particular sources, and the lack of a representative collection of diamonds from major producing areas that would be required for a rigorous scientific study. The jewelry industry has therefore adopted plans to track gem diamonds from the mine through the manufacturing process to the consumer. Practical requirements for implementation of such a certification system will be summarized. Any proposed solutions for determining the sources of gem diamonds by some analytical technique, or for following diamonds from the mine, must take into account the annual production of several tens of millions of carats of rough diamonds, which are transformed during manufacturing into several hundreds of millions of polished gemstones (with an average weight of only about 0.03 carat, or 0.006 gram).

Measurements of Polarization Transfers in Real Compton Scattering by a proton target at JLAB. A new source of information on the 3D shape of the nucleon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fanelli, Cristiano V.

2015-03-01

In this thesis work, results of the analysis of the polarization transfers measured in real Compton scattering (RCS) by the Collaboration E07-002 at the Je fferson Lab Hall-C are presented. The data were collected at large scattering angle (theta_cm = 70deg) and with a polarized incident photon beam at an average energy of 3.8 GeV. Such a kind of experiments allows one to understand more deeply the reaction mechanism, that involves a real photon, by extracting both Compton form factors and Generalized Parton Distributions (GPDs) (also relevant for possibly shedding light on the total angular momentum of the nucleon). Themore » obtained results for the longitudinal and transverse polarization transfers K_LL and K_LT, are of crucial importance, since they confirm unambiguously the disagreement between experimental data and pQCD prediction, as it was found in E99-114 experiment, and favor the Handbag mechanism. The E99-114 and E07-002 results can contribute to attract new interest on the great yield of the Compton scattering by a nucleon target, as demonstrated by the recent approval of an experimental proposal submitted to the Jefferson Lab PAC 42 for a Wide-angle Compton Scattering experiment, at 8 and 10 GeV Photon Energies. The new experiments approved to run with the updated 12 GeV electron beam at JLab, are characterized by much higher luminosities, and a new GEM tracker is under development to tackle the challenging backgrounds. Within this context, we present a new multistep tracking algorithm, based on (i) a Neural Network (NN) designed for a fast and efficient association of the hits measured by the GEM detector which allows the track identification, and (ii) the application of both a Kalman filter and Rauch-Tung-Striebel smoother to further improve the track reconstruction. The full procedure, i.e. NN and filtering, appears very promising, with high performances in terms of both association effciency and reconstruction accuracy, and these preliminary results will be discussed in detail in the last chapters.« less

A refined gravity model from Lageos /GEM-L2/

NASA Technical Reports Server (NTRS)

Lerch, F. J.; Klosko, S. M.; Patel, G. B.

1982-01-01

Lageos satellite laser ranging (SLR) data taken over a 2.5 yr period were employed to develop the Goddard Earth Model GEM-L2, a refined gravity field model. Additional data was gathered with 30 other satellites, resulting in spherical harmonics through degree and order 20, based on over 600,000 measurements. The Lageos data was accurate down to 10 cm, after which the GEM 9 data were used to make adjustments past order 7. The resolution of long wavelength activity, through degree and order 4, was made possible by the Lageos data. The GEM-L2 model features a 20 x 20 geopotential, tracking station coordinates (20), 5-day polar motion and A1-UT1 values, and a GM value of 398,600.607 cu km/sq sec. The accuracy of station positioning has been raised to within 6 cm total position globally and within 1.8 cm in baselines. It is concluded that SLR is useful for measuring tectonic plate motions and inter-plate deformations.

Geostationary Environment Monitoring Spectrometer (gems) Over the Korea Peninsula and Asia-Pacific Region

NASA Astrophysics Data System (ADS)

Lasnik, J.; Stephens, M.; Baker, B.; Randall, C.; Ko, D. H.; Kim, S.; Kim, Y.; Lee, E. S.; Chang, S.; Park, J. M.; SEO, S. B.; Youk, Y.; Kong, J. P.; Lee, D.; Lee, S. H.; Kim, J.

2014-12-01

Introduction: The Geostationary Environment Monitoring Spectrometer (GEMS) is one of two instruments manifested aboard the South Korean Geostationary Earth Orbit KOrea Multi-Purpose SATellite-2B (GEO-KOMPSAT-2B or GK2B), which is scheduled to launch in 2018. Jointly developed/built by KARI and Ball Aerospace, GEMS is a geostationary UV-Vis hyperspectral imager designed to monitor trans-boundary tropospheric pollution events over the Korean peninsula and Asia-Pacific region. The spectrometer provides high temporal and spatial resolution (3.5 km N/S by 7.2 km E/W) measurements of ozone, its precursors, and aerosols. Over the short-term, hourly measurements by GEMS will improve early warnings for potentially dangerous pollution events and monitor population exposure. Over the 10-year mission-life, GEMS will serve to enhance our understanding of long-term climate change and broader air quality issues on both a regional and global scale. The GEMS sensor design and performance are discussed, which includes an overview of measurement capabilities and the on-orbit concept of operations. GEMS Sensor Overview: The GEMS hyperspectral imaging system consists of a telescope and Offner grating spectrometer that feeds a single CCD detector array. A spectral range of 300-500 nm and sampling of 0.2 nm enables NO2, SO2, HCHO, O3, and aerosol retrieval. The GEMS field of regard (FOR), which extends from 5°S to 45°N in latitude and 75°E to 145°E in longitude, is operationally achieved using an onboard two-axis scan mirror. On-orbit, the radiometric calibration is maintained using solar measurements, which are performed using two onboard diffusers: a working diffuser that is deployed routinely for the purpose of solar calibration, and a reference diffuser that is deployed sparingly for the purpose of monitoring working diffuser performance degradation.

An improved error assessment for the GEM-T1 gravitational model

NASA Technical Reports Server (NTRS)

Lerch, F. J.; Marsh, J. G.; Klosko, S. M.; Pavlis, E. C.; Patel, G. B.; Chinn, D. S.; Wagner, C. A.

1988-01-01

Several tests were designed to determine the correct error variances for the Goddard Earth Model (GEM)-T1 gravitational solution which was derived exclusively from satellite tracking data. The basic method employs both wholly independent and dependent subset data solutions and produces a full field coefficient estimate of the model uncertainties. The GEM-T1 errors were further analyzed using a method based upon eigenvalue-eigenvector analysis which calibrates the entire covariance matrix. Dependent satellite and independent altimetric and surface gravity data sets, as well as independent satellite deep resonance information, confirm essentially the same error assessment. These calibrations (utilizing each of the major data subsets within the solution) yield very stable calibration factors which vary by approximately 10 percent over the range of tests employed. Measurements of gravity anomalies obtained from altimetry were also used directly as observations to show that GEM-T1 is calibrated. The mathematical representation of the covariance error in the presence of unmodeled systematic error effects in the data is analyzed and an optimum weighting technique is developed for these conditions. This technique yields an internal self-calibration of the error model, a process which GEM-T1 is shown to approximate.

Setup optimization toward accurate ageing studies of gas filled detectors

NASA Astrophysics Data System (ADS)

Abuhoza, A.; Schmidt, H. R.; Biswas, S.; Frankenfeld, U.; Hehner, J.; Schmidt, C. J.

2013-08-01

An infrastructure has been set up at the GSI detector laboratory to study the influence of construction materials on the ageing properties of gas filled detectors, such as multi-wire proportional chamber (MWPC), gas electron multiplier (GEM). Optimization of an ageing setup was performed by observing the variation of the normalized gain obtained using two identical MWPCs. An accuracy in the relative gain measurement below 1% has been achieved by monitoring environmental conditions and by systematic improvements of the measuring equipment. Ageing test of fiberglass G11 has been performed.

Development of 2D imaging of SXR plasma radiation by means of GEM detectors

NASA Astrophysics Data System (ADS)

Chernyshova, M.; Czarski, T.; Jabłoński, S.; Kowalska-Strzeciwilk, E.; Poźniak, K.; Kasprowicz, G.; Zabołotny, W.; Wojeński, A.; Byszuk, A.; Burza, M.; Juszczyk, B.; Zienkiewicz, P.

2014-11-01

Presented 2D gaseous detector system has been developed and designed to provide energy resolved fast dynamic plasma radiation imaging in the soft X-Ray region with 0.1 kHz exposure frequency for online, made in real time, data acquisition (DAQ) mode. The detection structure is based on triple Gas Electron Multiplier (GEM) amplification structure followed by the pixel readout electrode. The efficiency of detecting unit was adjusted for the radiation energy region of tungsten in high-temperature plasma, the main candidate for the plasma facing material for future thermonuclear reactors. Here we present preliminary laboratory results and detector parameters obtained for the developed system. The operational characteristics and conditions of the detector were designed to work in the X-Ray range of 2-17 keV. The detector linearity was checked using the fluorescence lines of different elements and was found to be sufficient for good photon energy reconstruction. Images of two sources through various screens were performed with an X-Ray laboratory source and 55Fe source showing a good imaging capability. Finally offline stream-handling data acquisition mode has been developed for the detecting system with timing down to the ADC sampling frequency rate (~13 ns), up to 2.5 MHz of exposure frequency, which could pave the way to invaluable physics information about plasma dynamics due to very good time resolving ability. Here we present results of studied spatial resolution and imaging properties of the detector for conditions of laboratory moderate counting rates and high gain.

Serial data acquisition for the X-ray plasma diagnostics with selected GEM detector structures

NASA Astrophysics Data System (ADS)

Czarski, T.; Chernyshova, M.; Pozniak, K. T.; Kasprowicz, G.; Zabolotny, W.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zienkiewicz, P.

2015-10-01

The measurement system based on GEM—Gas Electron Multiplier detector is developed for X-ray diagnostics of magnetic confinement tokamak plasmas. The paper is focused on the measurement subject and describes the fundamental data processing to obtain reliable characteristics (histograms) useful for physicists. The required data processing have two steps: 1—processing in the time domain, i.e. events selections for bunches of coinciding clusters, 2—processing in the planar space domain, i.e. cluster identification for the given detector structure. So, it is the software part of the project between the electronic hardware and physics applications. The whole project is original and it was developed by the paper authors. The previous version based on 1-D GEM detector was applied for the high-resolution X-ray crystal spectrometer KX1 in the JET tokamak. The current version considers 2-D detector structures for the new data acquisition system. The fast and accurate mode of data acquisition implemented in the hardware in real time can be applied for the dynamic plasma diagnostics. Several detector structures with single-pixel sensors and multi-pixel (directional) sensors are considered for two-dimensional X-ray imaging. Final data processing is presented by histograms for selected range of position, time interval and cluster charge values. Exemplary radiation source properties are measured by the basic cumulative characteristics: the cluster position distribution and cluster charge value distribution corresponding to the energy spectra. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

The TOTEM detector at LHC

NASA Astrophysics Data System (ADS)

Antchev, G.; Aspell, P.; Atanassov, I.; Avati, V.; Berardi, V.; Berretti, M.; Bozzo, M.; Brucken, E.; Buzzo, A.; Cafagna, F.; Calicchio, M.; Catanesi, M. G.; Ciocci, M. A.; Csanád, M.; Csörgő, T.; Deile, M.; Dénes, E.; Dimovasili, E.; Doubek, M.; Eggert, K.; Ferro, F.; Garcia, F.; Giani, S.; Greco, V.; Grzanka, L.; Heino, J.; Hilden, T.; Janda, M.; Kaˇspar, J.; Kopal, J.; Kundrat, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Lippmaa, E.; Lokajicek, M.; Lo Vetere, M.; Lucas Rodriguez, F.; Macri`, M.; Magazzu`, G.; Minutoli, S.; Niewiadomski, H.; Notarnicola, G.; Novak, T.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Osterberg, K.; Palazzi, P.; Pedreschi, E.; Petajajarvi, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Rummel, A.; Saarikko, H.; Sanguinetti, G.; Santroni, A.; Scribano, A.; Sette, G.; Snoeys, W.; Spearman, W.; Spinella, F.; Ster, A.; Taylor, C.; Trummal, A.; Turini, N.; Vacek, V.; Vitek, M.; Whitmore, J.; Wu, J.

2010-05-01

The TOTEM experiment, small in size compared to the others at the LHC, is dedicated to the measurement of the total proton-proton cross-sections with a luminosity-independent method and to the study of elastic and diffractive scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the IP5 interaction point, two tracking telescopes, T1 and T2, will be installed on each side in the pseudo-rapidity region between 3.1 and 6.5, and Roman Pot stations will be placed at distances of 147 and 220 m from IP5. The telescope closest to the interaction point (T1, centred at z=9 m) consists of Cathode Strip Chambers (CSC), while the second one (T2, centred at 13.5 m), makes use of Gas Electron Multipliers (GEM). The proton detectors in the Roman Pots are silicon devices designed by TOTEM with the specific objective of reducing down to a few tens of microns the insensitive area at the edge. High efficiency as close as possible to the physical detector boundary is an essential feature. It maximizes the experimental acceptance for protons scattered elastically or interactively at polar angles down to a few micro-radians at IP5. To measure protons at the lowest possible emission angles, special beam optics have been conceived to optimize proton detection in terms of acceptance and resolution. The read-out of all TOTEM subsystems is based on the custom-developed digital VFAT chip with trigger capability.

Utilization of satellite-satellite tracking data for determination of the geocentric gravitational constant (GM)

NASA Technical Reports Server (NTRS)

Martin, C. F.; Oh, I. H.

1979-01-01

Range rate tracking of GEOS 3 through the ATS 6 satellite was used, along with ground tracking of GEOS 3, to estimate the geocentric gravitational constant (GM). Using multiple half day arcs, a GM of 398600.52 + or - 0.12 cu km/sq sec was estimated using the GEM 10 gravity model, based on speed of light of 299792.458 km/sec. Tracking station coordinates were simultaneously adjusted, leaving geopotential model error as the dominant error source. Baselines between the adjusted NASA laser sites show better than 15 cm agreement with multiple short arc GEOS 3 solutions.

Working Gas Selection of the Honeycomb Converter-Based Neutron Detector

NASA Astrophysics Data System (ADS)

Fang, Zhujun; Yang, Yigang; Li, Yulan; Wang, Xuewu

2017-07-01

To reduce the manufacturing difficulty and improve the robustness of traditional boron-lined detectors that may replace the 3He counter, the honeycomb neutron converter-based gaseous neutron detector has been proposed. A drift electric field is applied to drive electrons ionized by α or 7Li after the 10B(n, α)7Li reaction from their origination positions to the incident surface of the gas electron multiplier (GEM), which multiplies electrons and forms the neutron signal. As the working gas affects the energy deposition of α or 7Li, the transverse diffusion of electrons in the migration process, as well as the multiplication of electrons in the GEM detector, the working gas selection of the honeycomb converter-based detector would be very important. Fourteen different working gases are investigated in detail through simulation research. Four working gases, Ar:iC4H10:CF4 = 90:7:3, Ar:CO2 = 95:5, Ar:CH4 = 90:10, and Ar:DME = 95:5, are experimentally tested. Both the simulation and experimental results demonstrate that working gases of Ar:iC4H10:CF4 = 90:7:3, Ar:CO2 = 95:5, and Ar:DME = 95:5 show good performances benefitting from both the large stopping powers of α or 7Li and the small transverse diffusion coefficients of electrons. The simulation results indicate that the detection efficiency with one of the three gases is 1.33 to 1.48 times the Ar:CH4 = 90:10, while the experimental results demonstrate that there is 1.34-1.49 times of the detection efficiency. The research in this paper helps improve the performance of the honeycomb converter-based neutron detector.

Exploring Cosmic X-ray Source Polarization

NASA Technical Reports Server (NTRS)

Swank, Jean Hebb; Jahodal, K.; Kallman, T. R.; Kaaret, P.

2008-01-01

Cosmic X-ray sources are expected to be polarized, either because of their asymmetry and the role of scattering in their emission or the role of magnetic fields. Polarization at other wavelengths has been useful. X-ray polarization will provide a new handle on black hole parameters, in particular the spin, on accretion flows and outflows, on neutron star spin orientations and emission mechanisms, on the quantum mechanical effects of super-strong magnetic fields of magnetars, and on the structure of supernovae shocks. The proposed Gravity and Extreme Magnetism SMEX (GEMS) will use high efficiency polarimeters behind thin foil mirrors. The statistical sensitivity and control of systematics will allow measurement of polarization fractions as small as 1% from many galactic and extragalactic sources. Targets which should be polarized at the level that GEMS can easily measure include stellar black holes, Seyfert galaxies and quasars, blazars, rotation-powered and accretion-powered pulsars, magnetars, shell supernova remnants and pulsar wind nebulae. The polarimeters are Time Projection Chambers that allow reconstruction of images of photoelectron tracks for 2-10 keV Xrays. They can be deep without sacrificing modulation. These polarimeters do not image the sky, but the telescope point spread function and detector collimation allow structure to be resolved at the 10 arcmin level. Rotation of the spacecraft is not needed for the signal measurement in the Time Projection Chambers, but provides for measurement and correction of systematic errors. It also allows a small Bragg reflection soft X-ray experiment to be included that can be used for isolated neutron stars and blazars.

Track analysis of laser-illuminated etched track detectors using an opto-digital imaging system

NASA Astrophysics Data System (ADS)

Eghan, Moses J.; Buah-Bassuah, Paul K.; Oppon, Osborne C.

2007-11-01

An opto-digital imaging system for counting and analysing tracks on a LR-115 detector is described. One batch of LR-115 track detectors was irradiated with Am-241 for a determined period and distance for linearity test and another batch was exposed to radon gas. The laser-illuminated etched track detector area was imaged, digitized and analysed by the system. The tracks that were counted on the opto-digital system with the aid of media cybernetics software as well as spark gap counter showed comparable track density results ranging between 1500 and 2750 tracks cm-2 and 65 tracks cm-2 in the two different batch detector samples with 0.5% and 1% track counts, respectively. Track sizes of the incident alpha particles from the radon gas on the LR-115 detector demonstrating different track energies are statistically and graphically represented. The opto-digital imaging system counts and measures other track parameters at an average process time of 3-5 s.

Algorithms development for the GEM-based detection system

NASA Astrophysics Data System (ADS)

Czarski, T.; Chernyshova, M.; Malinowski, K.; Pozniak, K. T.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zabolotny, W.

2016-09-01

The measurement system based on GEM - Gas Electron Multiplier detector - is developed for soft X-ray diagnostics of tokamak plasmas. The multi-channel setup is designed for estimation of the energy and the position distribution of an Xray source. The focal measuring issue is the charge cluster identification by its value and position estimation. The fast and accurate mode of the serial data acquisition is applied for the dynamic plasma diagnostics. The charge clusters are counted in the space determined by 2D position, charge value and time intervals. Radiation source characteristics are presented by histograms for a selected range of position, time intervals and cluster charge values corresponding to the energy spectra.

A novel application of Fiber Bragg Grating (FBG) sensors in MPGD

NASA Astrophysics Data System (ADS)

Abbaneo, D.; Abbas, M.; Abbrescia, M.; Abi Akl, M.; Aboamer, O.; Acosta, D.; Ahmad, A.; Ahmed, W.; Aleksandrov, A.; Altieri, P.; Asawatangtrakuldee, C.; Aspell, P.; Assran, Y.; Awan, I.; Bally, S.; Ban, Y.; Banerjee, S.; Barashko, V.; Barria, P.; Bencze, G.; Beni, N.; Benussi, L.; Bhopatkar, V.; Bianco, S.; Bos, J.; Bouhali, O.; Braghieri, A.; Braibant, S.; Buontempo, S.; Calabria, C.; Caponero, M.; Caputo, C.; Cassese, F.; Castaneda, A.; Cauwenbergh, S.; Cavallo, F. R.; Celik, A.; Choi, M.; Choi, S.; Christiansen, J.; Cimmino, A.; Colafranceschi, S.; Colaleo, A.; Conde Garcia, A.; Czellar, S.; Dabrowski, M. M.; De Lentdecker, G.; De Oliveira, R.; de Robertis, G.; Dildick, S.; Dorney, B.; Endroczi, G.; Errico, F.; Fenyvesi, A.; Ferrini, M.; Ferry, S.; Furic, I.; Giacomelli, P.; Gilmore, J.; Golovtsov, V.; Guiducci, L.; Guilloux, F.; Gutierrez, A.; Hadjiiska, R. M.; Hauser, J.; Hoepfner, K.; Hohlmann, M.; Hoorani, H.; Iaydjiev, P.; Jeng, Y. G.; Kamon, T.; Karchin, P.; Korytov, A.; Krutelyov, S.; Kumar, A.; Kim, H.; Lalli, A.; Lee, J.; Lenzi, T.; Litov, L.; Loddo, F.; Madorsky, A.; Maerschalk, T.; Maggi, M.; Magnani, A.; Mal, P. K.; Mandal, K.; Marchioro, A.; Marinov, A.; Majumdar, N.; Merlin, J. A.; Mitselmakher, G.; Mohanty, A. K.; Mohapatra, A.; Molnar, J.; Muhammad, S.; Mukhopadhyay, S.; Naimuddin, M.; Nuzzo, S.; Oliveri, E.; Pant, L. M.; Paolucci, P.; Park, I.; Passamonti, L.; Passeggio, G.; Pavlov, B.; Philipps, B.; Piccolo, D.; Pierluigi, D.; Postema, H.; Primavera, F.; Puig Baranac, A.; Radi, A.; Radogna, R.; Raffone, G.; Ranieri, A.; Rashevski, G.; Riccardi, C.; Rodozov, M.; Rodrigues, A.; Ropelewski, L.; RoyChowdhury, S.; Russo, A.; Ryu, G.; Ryu, M. S.; Safonov, A.; Salva, S.; Saviano, G.; Sharma, A.; Sharma, A.; Sharma, R.; Shah, A. H.; Shopova, M.; Sturdy, J.; Sultanov, G.; Swain, S. K.; Szillasi, Z.; Talvitie, J.; Tatarinov, A.; Tuuva, T.; Tytgat, M.; Valente, M.; Vai, I.; Van Stenis, M.; Venditti, R.; Verhagen, E.; Verwilligen, P.; Vitulo, P.; Volkov, S.; Vorobyev, A.; Wang, D.; Wang, M.; Yang, U.; Yang, Y.; Yonamine, R.; Zaganidis, N.; Zenoni, F.; Zhang, A.

2018-02-01

We present a novel application of Fiber Bragg Grating (FBG) sensors in the construction and characterisation of Micro Pattern Gaseous Detector (MPGD), with particular attention to the realisation of the largest triple (Gas electron Multiplier) GEM chambers so far operated, the GE1/1 chambers of the CMS experiment at LHC. The GE1/1 CMS project consists of 144 GEM chambers of about 0.5 m2 active area each, employing three GEM foils per chamber, to be installed in the forward region of the CMS endcap during the long shutdown of LHC in 2108-2019. The large active area of each GE1/1 chamber consists of GEM foils that are mechanically stretched in order to secure their flatness and the consequent uniform performance of the GE1/1 chamber across its whole active surface. So far FBGs have been used in high energy physics mainly as high precision positioning and re-positioning sensors and as low cost, easy to mount, low space consuming temperature sensors. FBGs are also commonly used for very precise strain measurements in material studies. In this work we present a novel use of FBGs as flatness and mechanical tensioning sensors applied to the wide GEM foils of the GE1/1 chambers. A network of FBG sensors have been used to determine the optimal mechanical tension applied and to characterise the mechanical tension that should be applied to the foils. We discuss the results of the test done on a full-sized GE1/1 final prototype, the studies done to fully characterise the GEM material, how this information was used to define a standard assembly procedure and possible future developments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hattemer-Frey, H.A.; Brandt, E.J.; Travis, C.C.

Commercial genetic engineering is advancing into areas that require the small-scale introduction of genetically engineered microorganisms (GEMs) to better quantify variables that affect microorganism distribution and survival and to document potential long-term consequences. A recombinant DNA marker system, the lacZY marker, developed by the Monsanto Agricultural Co., enables the distribution and fate of marked fluorescent pseudomonad organisms to be monitored under actual field conditions. Critical evaluation of GEMs under field conditions is imperative if plant-beneficial effects are to be correlated with organism release. This paper evaluates the effectiveness of this marker system and its ability to facilitate the assessment ofmore » risks associated with deliberate environmental introductions of genetically engineered microorganisms. Results of prerelease contained growth chamber and field experiments demonstrated that: (1) the scientific risk assessment methodology adopted by Monsanto and approved by the U.S. Environmental Protection Agency was appropriate and comprehensive; (2) the deliberate introduction of a GEM did not pose unacceptable or unforeseen risks to human health or the environment; (3) the lacZY marker is an effective environmental tracking tool; and (4) regulatory oversight should reflect the expected risk and not be excessively burdensome for all GEMs.« less

Embedded controller for GEM detector readout system

NASA Astrophysics Data System (ADS)

Zabołotny, Wojciech M.; Byszuk, Adrian; Chernyshova, Maryna; Cieszewski, Radosław; Czarski, Tomasz; Dominik, Wojciech; Jakubowska, Katarzyna L.; Kasprowicz, Grzegorz; Poźniak, Krzysztof; Rzadkiewicz, Jacek; Scholz, Marek

2013-10-01

This paper describes the embedded controller used for the multichannel readout system for the GEM detector. The controller is based on the embedded Mini ITX mainboard, running the GNU/Linux operating system. The controller offers two interfaces to communicate with the FPGA based readout system. FPGA configuration and diagnostics is controlled via low speed USB based interface, while high-speed setup of the readout parameters and reception of the measured data is handled by the PCI Express (PCIe) interface. Hardware access is synchronized by the dedicated server written in C. Multiple clients may connect to this server via TCP/IP network, and different priority is assigned to individual clients. Specialized protocols have been implemented both for low level access on register level and for high level access with transfer of structured data with "msgpack" protocol. High level functionalities have been split between multiple TCP/IP servers for parallel operation. Status of the system may be checked, and basic maintenance may be performed via web interface, while the expert access is possible via SSH server. System was designed with reliability and flexibility in mind.

The μ-RWELL: A compact, spark protected, single amplification-stage MPGD

NASA Astrophysics Data System (ADS)

Poli Lener, M.; Bencivenni, G.; de Olivera, R.; Felici, G.; Franchino, S.; Gatta, M.; Maggi, M.; Morello, G.; Sharma, A.

2016-07-01

In this work we present two innovative architectures of resistive MPGDs based on the WELL-amplification concept: - the micro-Resistive WELL (μ-RWELL) is a compact spark-protected single amplification-stage Micro-Pattern Gas Detector (MPGD). The amplification stage, realized with a structure very similar to a GEM foil (called WELL), is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new architecture, showing an excellent space resolution, 50 μm, is a very compact device, robust against discharges and exhibiting a large gain (>104), simple to construct and easy for engineering and then suitable for large area tracking devices as well as digital calorimeters. - the Fast Timing Micro-pattern (FTM): a new device with an architecture based on a stack of several coupled full-resistive layers where drift and multiplication stages (WELL type) alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings, providing a signal with a gain of 104-105. The main advantage of this new device is the improvement of the timing provided by the competition of the ionization processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as for applications like medical imaging.

Study of the dE/dx resolution of a GEM Readout Chamber prototype for the upgrade of the ALICE TPC

NASA Astrophysics Data System (ADS)

Mathis, Andreas

2018-02-01

The ALICE Collaboration is planning a major upgrade of its central barrel detectors to be able to cope with the increased LHC luminosity beyond 2020. For the TPC, this implies a replacement of the currently used gated MWPCs (Multi-Wire Proportional Chamber) by GEM (Gas Electron Multiplier) based readout chambers. In order to prove, that the present particle identification capabilities via measurement of the specific energy loss are retained after the upgrade, a prototype of the ALICE IROC (Inner Readout Chamber) has been evaluated in a test beam campaign at the CERN PS. The dE/dx resolution of the prototype has been proven to be fully compatible with the current MWPCs.

Neural network tracking and extension of positive tracking periods

NASA Technical Reports Server (NTRS)

Hanan, Jay C.; Chao, Tien-Hsin; Moreels, Pierre

2004-01-01

Feature detectors have been considered for the role of supplying additional information to a neural network tracker. The feature detector focuses on areas of the image with significant information. Basically, if a picture says a thousand words, the feature detectors are looking for the key phrases (keypoints). These keypoints are rotationally invariant and may be matched across frames. Application of these advanced feature detectors to the neural network tracking system at JPL has promising potential. As part of an ongoing program, an advanced feature detector was tested for augmentation of a neural network based tracker. The advance feature detector extended tracking periods in test sequences including aircraft tracking, rover tracking, and simulated Martian landing. Future directions of research are also discussed.

Neural network tracking and extension of positive tracking periods

NASA Astrophysics Data System (ADS)

Hanan, Jay C.; Chao, Tien-Hsin; Moreels, Pierre

2004-04-01

Feature detectors have been considered for the role of supplying additional information to a neural network tracker. The feature detector focuses on areas of the image with significant information. Basically, if a picture says a thousand words, the feature detectors are looking for the key phrases (keypoints). These keypoints are rotationally invariant and may be matched across frames. Application of these advanced feature detectors to the neural network tracking system at JPL has promising potential. As part of an ongoing program, an advanced feature detector was tested for augmentation of a neural network based tracker. The advance feature detector extended tracking periods in test sequences including aircraft tracking, rover tracking, and simulated Martian landing. Future directions of research are also discussed.

Optimum data weighting and error calibration for estimation of gravitational parameters

NASA Technical Reports Server (NTRS)

Lerch, Francis J.

1989-01-01

A new technique was developed for the weighting of data from satellite tracking systems in order to obtain an optimum least-squares solution and an error calibration for the solution parameters. Data sets from optical, electronic, and laser systems on 17 satellites in GEM-T1 Goddard Earth Model-T1 (GEM-T1) were employed toward application of this technique for gravity field parameters. Also GEM-T2 (31 satellites) was recently computed as a direct application of the method and is summarized. The method employs subset solutions of the data associated with the complete solution to agree with their error estimates. With the adjusted weights the process provides for an automatic calibration of the error estimates for the solution parameters. The data weights derived are generally much smaller than corresponding weights obtained from nominal values of observation accuracy or residuals. Independent tests show significant improvement for solutions with optimal weighting. The technique is general and may be applied to orbit parameters, station coordinates, or other parameters than the gravity model.

High resolution track etch autoradiography

DOEpatents

Solares, G.; Zamenhof, R.G.

1994-12-27

A detector assembly is disclosed for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns. 13 figures.

High resolution track etch autoradiography

DOEpatents

Solares, Guido; Zamenhof, Robert G.

1994-01-01

A detector assembly for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns.

Reduced complexity of multi-track joint 2-D Viterbi detectors for bit-patterned media recording channel

NASA Astrophysics Data System (ADS)

Myint, L. M. M.; Warisarn, C.

2017-05-01

Two-dimensional (2-D) interference is one of the prominent challenges in ultra-high density recording system such as bit patterned media recording (BPMR). The multi-track joint 2-D detection technique with the help of the array-head reading can tackle this problem effectively by jointly processing the multiple readback signals from the adjacent tracks. Moreover, it can robustly alleviate the impairments due to track mis-registration (TMR) and media noise. However, the computational complexity of such detectors is normally too high and hard to implement in a reality, even for a few multiple tracks. Therefore, in this paper, we mainly focus on reducing the complexity of multi-track joint 2-D Viterbi detector without paying a large penalty in terms of the performance. We propose a simplified multi-track joint 2-D Viterbi detector with a manageable complexity level for the BPMR's multi-track multi-head (MTMH) system. In the proposed method, the complexity of detector's trellis is reduced with the help of the joint-track equalization method which employs 1-D equalizers and 2-D generalized partial response (GPR) target. Moreover, we also examine the performance of a full-fledged multi-track joint 2-D detector and the conventional 2-D detection. The results show that the simplified detector can perform close to the full-fledge detector, especially when the system faces high media noise, with the significant low complexity.

Development of the GEM-TPC X-ray Polarimeter with the Scalable Readout System

NASA Astrophysics Data System (ADS)

Kitaguchi, Takao; Hayato, Asami; Iwakiri, Wataru; Takeuchi, Yoko; Kubota, Megu; Nishida, Kazuki; Enoto, Teruaki; Tamagawa, Toru

2018-02-01

We have developed a gaseous Time Projection Chamber (TPC) containing a single-layered foil of a gas electron multiplier (GEM) to open up a new window on cosmic X-ray polarimetry in the 2-10 keV band. The micro-pattern TPC polarimeter in combination with the Scalable Readout System produced by the RD51 collaboration has been built as an engineering model to optimize detector parameters and improve polarimeter sensitivity. The polarimeter was characterized with unpolarized X-rays from an X-ray generator in a laboratory and polarized X-rays on the BL32B2 beamline at the SPring-8 synchrotron radiation facility. Preliminary results show that the polarimeter has a comparable modulation factor to a prototype of the flight one.

Gravity model improvement using the DORIS tracking system on the SPOT 2 satellite

NASA Technical Reports Server (NTRS)

Nerem, R. S.; Lerch, F. J.; Williamson, R. G.; Klosko, S. M.; Robbins, J. W.; Patel, G. B.

1994-01-01

A high-precision radiometric satellite tracking system, Doppler Orbitography and Radio-positioning Integrated by Satellite system (DORIS), has recently been developed by the French space agency, Centre National d'Etudes Spatiales (CNES). DORIS was designed to provide tracking support for missions such as the joint United States/French TOPEX/Poseidon. As part of the flight testing process, a DORIS package was flown on the French SPOT 2 satellite. A substantial quantity of geodetic quality tracking data was obtained on SPOT 2 from an extensive international DORIS tracking network. These data were analyzed to assess their accuracy and to evaluate the gravitational modeling enhancements provided by these data in combination with the Goddard Earth Model-T3 (GEM-T3) gravitational model. These observations have noise levels of 0.4 to 0.5 mm/s, with few residual systematic effects. Although the SPOT 2 satellite experiences high atmospheric drag forces, the precision and global coverage of the DORIS tracking data have enabled more extensive orbit parameterization to mitigate these effects. As a result, the SPOT 2 orbital errors have been reduced to an estimated radial accuracy in the 10-20 cm RMS range. The addition of these data, which encompass many regions heretofore lacking in precision satellite tracking, has significantly improved GEM-T3 and allowed greatly improved orbit accuracies for Sun-synchronous satellites like SPOT 2 (such as ERS 1 and EOS). Comparison of the ensuing gravity model with other contemporary fields (GRIM-4C2, TEG2B, and OSU91A) provides a means to assess the current state of knowledge of the Earth's gravity field. Thus, the DORIS experiment on SPOT 2 has provided a strong basis for evaluating this new orbit tracking technology and has demonstrated the important contribution of the DORIS network to the success of the TOPEX/Poseidon mission.

Beam-based measurement of the center of the new STAR pipe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert-Demolaize, G.

During the RHIC Shutdown preceding Run13 for polarized protons, various upgrades were brought to the STAR detector, one of which being the partial installation of the Forward GEM Tracker (FGT). This installation includes a new beam pipe at the center of the detector with an internal radius half the size of what the replaced pipe was, from 40 mm to 20 mm. The following reviews the results of a vertical aperture scans in the STAR interaction region performed at injection energy with both beams, and gives an estimate of the measured transverse offset of the new STAR pipe.

A custom readout electronics for the BESIII CGEM detector

NASA Astrophysics Data System (ADS)

Da Rocha Rolo, M.; Alexeev, M.; Amoroso, A.; Baldini Ferroli, R.; Bertani, M.; Bettoni, D.; Bianchi, F.; Bugalho, R.; Calcaterra, A.; Canale, N.; Capodiferro, M.; Carassiti, V.; Cerioni, S.; Chai, J. Y.; Chiozzi, S.; Cibinetto, G.; Cossio, F.; Cotta Ramusino, A.; De Mori, F.; Destefanis, M.; Di Francesco, A.; Dong, J.; Evangelisti, F.; Farinelli, R.; Fava, L.; Felici, G.; Fioravanti, E.; Garzia, I.; Gatta, M.; Greco, M.; Lavezzi, L.; Leng, C. Y.; Li, H.; Maggiora, M.; Malaguti, R.; Marcello, S.; Marciniewski, P.; Melchiorri, M.; Mezzadri, G.; Mignone, M.; Morello, G.; Pacetti, S.; Patteri, P.; Pellegrino, J.; Pelosi, A.; Rivetti, A.; Savrié, M.; Scodeggio, M.; Soldani, E.; Sosio, S.; Spataro, S.; Tskhadadze, E.; Varela, J.; Verma, S.; Wheadon, R.; Yan, L.

2017-07-01

For the upgrade of the inner tracker of the BESIII spectrometer, planned for 2018, a lightweight tracker based on an innovative Cylindrical Gas Electron Multiplier (CGEM) detector is now under development. The analogue readout of the CGEM enables the use of a charge centroid algorithm to improve the spatial resolution to better than 130 μm while loosening the pitch strip to 650 μm, which allows to reduce the total number of channels to about 10 000. The channels are readout by 160 dedicated integrated 64-channel front-end ASICs, providing a time and charge measurement and featuring a fully-digital output. The energy measurement is extracted either from the time-over-threshold (ToT) or the 10-bit digitisation of the peak amplitude of the signal. The time of the event is generated by quad-buffered low-power TDCs, allowing for rates in excess of 60 kHz per channel. The TDCs are based on analogue interpolation techniques and produce a time stamp (or two, if working in ToT mode) of the event with a time resolution better than 50 ps. The front-end noise, based on a CSA and a two-stage complex conjugated pole shapers, dominate the channel intrinsic time jitter, which is less than 5 ns r.m.s. The time information of the hit can be used to reconstruct the track path, operating the detector as a small TPC and hence improving the position resolution when the distribution of the cloud, due to large incident angle or magnetic field, is very broad. Event data is collected by an off-detector motherboard, where each GEM-ROC readout card handles 4 ASIC carrier FEBs (512 channels). Configuration upload and data readout between the off-detector electronics and the VME-based data collector cards are managed by bi-directional fibre optical links. This paper covers the design of a custom front-end electronics for the readout of the new inner tracker of the BESIII experiment, addressing the relevant design aspects of the detector electronics and the front-end ASIC for the CGEM readout, and reviewing the first silicon results of the chip prototype.

Multichannel reconfigurable measurement system for hot plasma diagnostics based on GEM-2D detector

NASA Astrophysics Data System (ADS)

Wojenski, A. J.; Kasprowicz, G.; Pozniak, K. T.; Byszuk, A.; Chernyshova, M.; Czarski, T.; Jablonski, S.; Juszczyk, B.; Zienkiewicz, P.

2015-12-01

In the future magnetically confined fusion research reactors (e.g. ITER tokamak), precise determination of the level of the soft X-ray radiation of plasma with temperature above 30 keV (around 350 mln K) will be very important in plasma parameters optimization. This paper presents the first version of a designed spectrography measurement system. The system is already installed at JET tokamak. Based on the experience gained from the project, the new generation of hardware for spectrography measurements, was designed and also described in the paper. The GEM detector readout structure was changed to 2D in order to perform measurements of i.e. laser generated plasma. The hardware structure of the system was redesigned in order to provide large number of high speed input channels. Finally, this paper also covers the issue of new control software, necessary to set-up a complete system of certain complexity and perform data acquisition. The main goal of the project was to develop a new version of the system, which includes upgraded structure and data transmission infrastructure (i.e. handling large number of measurement channels, high sampling rate).

Pulsed-neutron imaging by a high-speed camera and center-of-gravity processing

NASA Astrophysics Data System (ADS)

Mochiki, K.; Uragaki, T.; Koide, J.; Kushima, Y.; Kawarabayashi, J.; Taketani, A.; Otake, Y.; Matsumoto, Y.; Su, Y.; Hiroi, K.; Shinohara, T.; Kai, T.

2018-01-01

Pulsed-neutron imaging is attractive technique in the research fields of energy-resolved neutron radiography and RANS (RIKEN) and RADEN (J-PARC/JAEA) are small and large accelerator-driven pulsed-neutron facilities for its imaging, respectively. To overcome the insuficient spatial resolution of the conunting type imaging detectors like μ NID, nGEM and pixelated detectors, camera detectors combined with a neutron color image intensifier were investigated. At RANS center-of-gravity technique was applied to spots image obtained by a CCD camera and the technique was confirmed to be effective for improving spatial resolution. At RADEN a high-frame-rate CMOS camera was used and super resolution technique was applied and it was recognized that the spatial resolution was futhermore improved.

New approach to calculate the true-coincidence effect of HpGe detector

NASA Astrophysics Data System (ADS)

Alnour, I. A.; Wagiran, H.; Ibrahim, N.; Hamzah, S.; Siong, W. B.; Elias, M. S.

2016-01-01

The corrections for true-coincidence effects in HpGe detector are important, especially at low source-to-detector distances. This work established an approach to calculate the true-coincidence effects experimentally for HpGe detectors of type Canberra GC3018 and Ortec GEM25-76-XLB-C, which are in operation at neutron activation analysis lab in Malaysian Nuclear Agency (NM). The correction for true-coincidence effects was performed close to detector at distances 2 and 5 cm using 57Co, 60Co, 133Ba and 137Cs as standard point sources. The correction factors were ranged between 0.93-1.10 at 2 cm and 0.97-1.00 at 5 cm for Canberra HpGe detector; whereas for Ortec HpGe detector ranged between 0.92-1.13 and 0.95-100 at 2 and 5 cm respectively. The change in efficiency calibration curve of the detector at 2 and 5 cm after correction was found to be less than 1%. Moreover, the polynomial parameters functions were simulated through a computer program, MATLAB in order to find an accurate fit to the experimental data points.

Scintillator-fiber charged-particle track-imaging detector

NASA Technical Reports Server (NTRS)

Binns, W. R.; Israel, M. H.; Klarmann, J.

1983-01-01

A scintillator-fiber charged-particle track-imaging detector has been developed using a bundle of square cross-section plastic scintillator fiber optics, proximity focused onto an image intensified Charge Injection Device (CID) camera. Detector to beams of 15 MeV protons and relativistic Neon, Manganese, and Gold nuclei have been exposed and images of their tracks are obtained. This paper presents details of the detector technique, properties of the tracks obtained, and range measurements of 15 MeV protons stopping in the fiber bundle.

Nuclear Track Detector Characterization via Alpha-Spectrometry for Radioprotection Use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morelli, D.; Imme, G.; Catalano, R.

2011-12-13

Solid Nuclear Track Detectors (SNTDs), CR-39 type, are usually adopted to monitor radon gas concentrations. In order to characterize the detectors according to track geometrical parameters, detectors were irradiated inside a vacuum chamber by alpha particles at twelve energy values, obtained by different Mylar foils in front of a {sup 241}Am source. The alpha energy values were verified using a Si detector. After the exposure to the alpha particles, the detectors were chemically etched to enlarge the tracks, which were then analyzed by means of a semiautomatic system composed of an optical microscope equipped with a CCD camera connected tomore » a personal computer to store images. A suitable routine analyzed the track parameters: major and minor axis length and mean grey level, allowing us to differentiate tracks according to the incident alpha energy and then to individuate the discrimination factors for radon alpha tracks. The combined use of geometrical and optical parameters allows one to overcome the ambiguity in the alpha energy determination due to the non-monotonicity of each parameter versus energy. After track parameter determination, a calibration procedure was performed by means of a radon chamber. The calibration was verified through an inter-comparing survey.« less

Scintillator-fiber charged particle track-imaging detector

NASA Technical Reports Server (NTRS)

Binns, W. R.; Israel, M. H.; Klarmann, J.

1983-01-01

A scintillator-fiber charged-particle track-imaging detector was developed using a bundle of square cross section plastic scintillator fiber optics, proximity focused onto an image intensified charge injection device (CID) camera. The tracks of charged particle penetrating into the scintillator fiber bundle are projected onto the CID camera and the imaging information is read out in video format. The detector was exposed to beams of 15 MeV protons and relativistic Neon, Manganese, and Gold nuclei and images of their tracks were obtained. Details of the detector technique, properties of the tracks obtained, and preliminary range measurements of 15 MeV protons stopping in the fiber bundle are presented.

Determination of time zero from a charged particle detector

DOEpatents

Green, Jesse Andrew [Los Alamos, NM

2011-03-15

A method, system and computer program is used to determine a linear track having a good fit to a most likely or expected path of charged particle passing through a charged particle detector having a plurality of drift cells. Hit signals from the charged particle detector are associated with a particular charged particle track. An initial estimate of time zero is made from these hit signals and linear tracks are then fit to drift radii for each particular time-zero estimate. The linear track having the best fit is then searched and selected and errors in fit and tracking parameters computed. The use of large and expensive fast detectors needed to time zero in the charged particle detectors can be avoided by adopting this method and system.

Tracking Detectors in the STAR Experiment at RHIC

NASA Astrophysics Data System (ADS)

Wieman, Howard

2015-04-01

The STAR experiment at RHIC is designed to measure and identify the thousands of particles produced in 200 Gev/nucleon Au on Au collisions. This talk will focus on the design and construction of two of the main tracking detectors in the experiment, the TPC and the Heavy Flavor Tracker (HFT) pixel detector. The TPC is a solenoidal gas filled detector 4 meters in diameter and 4.2 meters long. It provides precise, continuous tracking and rate of energy loss in the gas (dE/dx) for particles at + - 1 units of pseudo rapidity. The tracking in a half Tesla magnetic field measures momentum and dE/dX provides particle ID. To detect short lived particles tracking close to the point of interaction is required. The HFT pixel detector is a two-layered, high resolution vertex detector located at a few centimeters radius from the collision point. It determines origins of the tracks to a few tens of microns for the purpose of extracting displaced vertices, allowing the identification of D mesons and other short-lived particles. The HFT pixel detector uses detector chips developed by the IPHC group at Strasbourg that are based on standard IC Complementary Metal-Oxide-Semiconductor (CMOS) technology. This is the first time that CMOS pixel chips have been incorporated in a collider application.

Intercomparison of retrospective radon detectors.

PubMed Central

Field, R W; Steck, D J; Parkhurst, M A; Mahaffey, J A; Alavanja, M C

1999-01-01

We performed both a laboratory and a field intercomparison of two novel glass-based retrospective radon detectors previously used in major radon case-control studies performed in Missouri and Iowa. The new detectors estimate retrospective residential radon exposure from the accumulation of a long-lived radon decay product, (210)Pb, in glass. The detectors use track registration material in direct contact with glass surfaces to measure the alpha-emission of a (210)Pb-decay product, (210)Po. The detector's track density generation rate (tracks per square centimeter per hour) is proportional to the surface alpha-activity. In the absence of other strong sources of alpha-emission in the glass, the implanted surface alpha-activity should be proportional to the accumulated (210)Po, and hence to the cumulative radon gas exposure. The goals of the intercomparison were to a) perform collocated measurements using two different glass-based retrospective radon detectors in a controlled laboratory environment to compare their relative response to implanted polonium in the absence of environmental variation, b) perform collocated measurements using two different retrospective radon progeny detectors in a variety of residential settings to compare their detection of glass-implanted polonium activities, and c) examine the correlation between track density rates and contemporary radon gas concentrations. The laboratory results suggested that the materials and methods used by the studies produced similar track densities in detectors exposed to the same implanted (210)Po activity. The field phase of the intercomparison found excellent agreement between the track density rates for the two types of retrospective detectors. The correlation between the track density rates and direct contemporary radon concentration measurements was relatively high, considering that no adjustments were performed to account for either the residential depositional environment or glass surface type. Preliminary comparisons of the models used to translate track rate densities to average long-term radon concentrations differ between the two studies. Further calibration of the retrospective detectors' models for interpretation of track rate density may allow the pooling of studies that use glass-based retrospective radon detectors to determine historic residential radon exposures. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10545336

Intercomparison of retrospective radon detectors.

PubMed

Field, R W; Steck, D J; Parkhurst, M A; Mahaffey, J A; Alavanja, M C

1999-11-01

We performed both a laboratory and a field intercomparison of two novel glass-based retrospective radon detectors previously used in major radon case-control studies performed in Missouri and Iowa. The new detectors estimate retrospective residential radon exposure from the accumulation of a long-lived radon decay product, (210)Pb, in glass. The detectors use track registration material in direct contact with glass surfaces to measure the alpha-emission of a (210)Pb-decay product, (210)Po. The detector's track density generation rate (tracks per square centimeter per hour) is proportional to the surface alpha-activity. In the absence of other strong sources of alpha-emission in the glass, the implanted surface alpha-activity should be proportional to the accumulated (210)Po, and hence to the cumulative radon gas exposure. The goals of the intercomparison were to a) perform collocated measurements using two different glass-based retrospective radon detectors in a controlled laboratory environment to compare their relative response to implanted polonium in the absence of environmental variation, b) perform collocated measurements using two different retrospective radon progeny detectors in a variety of residential settings to compare their detection of glass-implanted polonium activities, and c) examine the correlation between track density rates and contemporary radon gas concentrations. The laboratory results suggested that the materials and methods used by the studies produced similar track densities in detectors exposed to the same implanted (210)Po activity. The field phase of the intercomparison found excellent agreement between the track density rates for the two types of retrospective detectors. The correlation between the track density rates and direct contemporary radon concentration measurements was relatively high, considering that no adjustments were performed to account for either the residential depositional environment or glass surface type. Preliminary comparisons of the models used to translate track rate densities to average long-term radon concentrations differ between the two studies. Further calibration of the retrospective detectors' models for interpretation of track rate density may allow the pooling of studies that use glass-based retrospective radon detectors to determine historic residential radon exposures.

Effect of electron beam cooling on transversal and longitudinal emittance of an external proton beam

NASA Astrophysics Data System (ADS)

Kilian, K.; Machner, H.; Magiera, A.; Prasuhn, D.; von Rossen, P.; Siudak, R.; Stein, H. J.; Stockhorst, H.

2018-02-01

Benefits of electron cooling to the quality of extracted ion beams from storage rings are discussed. The transversal emittances of an external proton beam with and without electron cooling at injection energy are measured with the GEM detector assembly. While the horizontal emittance remains the vertical emittance shrinks by the cooling process. The longitudinal momentum variance is also reduced by cooling.

New approach to calculate the true-coincidence effect of HpGe detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alnour, I. A., E-mail: aaibrahim3@live.utm.my, E-mail: ibrahim.elnour@yahoo.com; Wagiran, H.; Ibrahim, N.

The corrections for true-coincidence effects in HpGe detector are important, especially at low source-to-detector distances. This work established an approach to calculate the true-coincidence effects experimentally for HpGe detectors of type Canberra GC3018 and Ortec GEM25-76-XLB-C, which are in operation at neutron activation analysis lab in Malaysian Nuclear Agency (NM). The correction for true-coincidence effects was performed close to detector at distances 2 and 5 cm using {sup 57}Co, {sup 60}Co, {sup 133}Ba and {sup 137}Cs as standard point sources. The correction factors were ranged between 0.93-1.10 at 2 cm and 0.97-1.00 at 5 cm for Canberra HpGe detector; whereas for Ortec HpGemore » detector ranged between 0.92-1.13 and 0.95-100 at 2 and 5 cm respectively. The change in efficiency calibration curve of the detector at 2 and 5 cm after correction was found to be less than 1%. Moreover, the polynomial parameters functions were simulated through a computer program, MATLAB in order to find an accurate fit to the experimental data points.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radousky, H B

This months issue has the following articles: (1) Innovative Solutions Reap Rewards--Commentary by George H. Miller; (2) Surveillance on the Fly--An airborne surveillance system can track up to 8,000 moving objects in an area the size of a small city; (3) A Detector Radioactive Particles Can't Evade--An ultrahigh-resolution spectrometer can detect the minute thermal energy deposited by a single gamma ray or neutron; (4) Babel Speeds Communication among Programming Languages--The Babel program allows software applications in different programming languages to communicate quickly; (5) A Gem of a Software Tool--The data-mining software Sapphire allows scientists to analyze enormous data sets generatedmore » by diverse applications; (6) Interferometer Improves the Search for Planets--With externally dispersed interferometry, astronomers can use an inexpensive, compact instrument to search for distant planets; (7) Efficiently Changing the Color of Laser Light--Yttrium-calcium-oxyborate crystals provide an efficient, compact approach to wavelength conversion for high-average-power lasers; (8) Pocket-Sized Test Detects Trace Explosives--A detection kit sensitive to more than 30 explosives provides an inexpensive, easy-to-use tool for security forces everywhere; (9) Tailor-Made Microdevices Serve Big Needs--The Center for Micro- and Nanotechnology develops tiny devices for national security.« less

Cargo Container Imaging with Gaseous Detectors

NASA Astrophysics Data System (ADS)

Forest, Tony

2006-10-01

The gas electron multiplier (GEM) , developed at CERN by Fabio Sauli, represents the latest innovation in micropattern gaseous detectors and has been utilized as a preamplification stage in applications ranging from fundamental physics experiments to medical imaging. Although cargo container inspection systems are currently in place using gamma-rays or X-rays, they are predominantly designed with a resolution to detect contraband. Current imaging systems also suffer from false alarms due to naturally radioactive cargo when radiation portal monitors are used for passive detection of nuclear materials. Detection of small shielded radioactive elements is even more problematic. Idaho State University has been developing a system to image cargo containers in order to detect small shielded radioactive cargo. The possible application of an imaging system with gas electron multiplication will be shown along with preliminary images using gaseous detectors instead of the scintillators currently in use.

[Design of longitudinal auto-tracking of the detector on X-ray in digital radiography].

PubMed

Yu, Xiaomin; Jiang, Tianhao; Liu, Zhihong; Zhao, Xu

2018-04-01

One algorithm is designed to implement longitudinal auto-tracking of the the detector on X-ray in the digital radiography system (DR) with manual collimator. In this study, when the longitudinal length of field of view (LFOV) on the detector is coincided with the longitudinal effective imaging size of the detector, the collimator half open angle ( Ψ ), the maximum centric distance ( e max ) between the center of X-ray field of view and the projection center of the focal spot, and the detector moving distance for auto-traking can be calculated automatically. When LFOV is smaller than the longitudinal effective imaging size of the detector by reducing Ψ , the e max can still be used to calculate the detector moving distance. Using this auto-tracking algorithm in DR with manual collimator, the tested results show that the X-ray projection is totally covered by the effective imaging area of the detector, although the center of the field of view is not aligned with the center of the effective imaging area of the detector. As a simple and low-cost design, the algorithm can be used for longitudinal auto-tracking of the detector on X-ray in the manual collimator DR.

Image processing analysis of nuclear track parameters for CR-39 detector irradiated by thermal neutron

NASA Astrophysics Data System (ADS)

Al-Jobouri, Hussain A.; Rajab, Mustafa Y.

2016-03-01

CR-39 detector which covered with boric acid (H3Bo3) pellet was irradiated by thermal neutrons from (241Am - 9Be) source with activity 12Ci and neutron flux 105 n. cm-2. s-1. The irradiation times -TD for detector were 4h, 8h, 16h and 24h. Chemical etching solution for detector was sodium hydroxide NaOH, 6.25N with 45 min etching time and 60 C˚ temperature. Images of CR-39 detector after chemical etching were taken from digital camera which connected from optical microscope. MATLAB software version 7.0 was used to image processing. The outputs of image processing of MATLAB software were analyzed and found the following relationships: (a) The irradiation time -TD has behavior linear relationships with following nuclear track parameters: i) total track number - NT ii) maximum track number - MRD (relative to track diameter - DT) at response region range 2.5 µm to 4 µm iii) maximum track number - MD (without depending on track diameter - DT). (b) The irradiation time -TD has behavior logarithmic relationship with maximum track number - MA (without depending on track area - AT). The image processing technique principally track diameter - DT can be take into account to classification of α-particle emitters, In addition to the contribution of these technique in preparation of nano- filters and nano-membrane in nanotechnology fields.

On charged particle tracks in cellulose nitrate and Lexan

NASA Technical Reports Server (NTRS)

Benton, E. V.; Henke, R. P.

1972-01-01

Investigations were performed aimed at developing plastic nuclear track detectors into quantitative tools for recording and measuring multicharged, heavy particles. Accurate track etch rate measurements as a function of LET were performed for cellulose nitrate and Lexan plastic detectors. This was done using a variety of incident charged particle types and energies. The effect of aging of latent tracks in Lexan in different gaseous atmospheres was investigated. Range distributions of high energy N-14 particle bevatron beams in nuclear emulsion were measured. Investigation of charge resolution and Bragg peak measurements were carried out using plastic nuclear track detectors.

Development of the ZEUS central tracking detector

NASA Astrophysics Data System (ADS)

Brooks, C. B.; Bullock, F. W.; Cashmore, R. J.; Devenish, R. C.; Foster, B.; Fraser, T. J.; Gibson, M. D.; Gilmore, R. S.; Gingrich, D.; Harnew, N.; Hart, J. C.; Heath, G. P.; Hiddleston, J.; Holmes, A. R.; Jamdagni, A. K.; Jones, T. W.; Llewellyn, T. J.; Long, K. R.; Lush, G. J.; Malos, J.; Martin, N. C.; McArthur, I.; McCubbin, N. A.; McQuillan, D.; Miller, D. B.; Mobayyen, M. M.; Morgado, C.; Nash, J.; Nixon, G.; Parham, A. G.; Payne, B. T.; Roberts, J. H. C.; Salmon, G.; Saxon, D. H.; Sephton, A. J.; Shaw, D.; Shaw, T. B.; Shield, P. D.; Shulman, J.; Silvester, I.; Smith, S.; Strachan, D. E.; Tapper, R. J.; Tkaczyk, S. M.; Toudup, L. W.; Wallis, E. W.; Wastie, R.; Wells, J.; White, D. J.; Wilson, F. F.; Yeo, K. L.; ZEUS-UK Collaboration

1989-11-01

The design concept and development of the ZEUS central tracking detector is described. This is a cylindrical drift chamber designed for track reconstruction, electron identification and event triggering in a high-crossing-rate, high-magnetic-field environment.

Angular resolution of the gaseous micro-pixel detector Gossip

NASA Astrophysics Data System (ADS)

Bilevych, Y.; Blanco Carballo, V.; van Dijk, M.; Fransen, M.; van der Graaf, H.; Hartjes, F.; Hessey, N.; Koppert, W.; Nauta, S.; Rogers, M.; Romaniouk, A.; Veenhof, R.

2011-06-01

Gossip is a gaseous micro-pixel detector with a very thin drift gap intended for a high rate environment like at the pixel layers of ATLAS at the sLHC. The detector outputs not only the crossing point of a traversing MIP, but also the angle of the track, thus greatly simplifying track reconstruction. In this paper we describe a testbeam experiment to examine the angular resolution of the reconstructed track segments in Gossip. We used here the low diffusion gas mixture DME/CO 2 50/50. An angular resolution of 20 mrad for perpendicular tracks could be obtained from a 1.5 mm thin drift volume. However, for the prototype detector used at the testbeam experiment, the resolution of slanting tracks was worsened by poor time resolution of the pixel chip used.

Calibrations for Charged Particle Tracking with the GlueX Detector

NASA Astrophysics Data System (ADS)

Staib, Michael; GlueX Collaboration

2015-10-01

Two gas detectors comprise the tracking system for the GlueX experiment, the Central Drift Chamber (CDC) and the Forward Drift Chamber (FDC). The CDC is a cylindrical straw-tube detector covering polar angles between 6° and 168°, delivering spatial resolution of ~150 μm. The FDC is a Cathode Strip Chamber consisting of four packages, each with six alternating layers of anode wires and cathode strips. The FDC is designed to track forward-going charged particles with polar angles between 1° and 20° with a spatial resolution of ~200 μm. Both tracking detectors record timing information and energy loss measurements useful for particle identification. During Fall 2014 and Spring 2015, the first photon beam was delivered on target for commissioning of the GlueX detector in Hall-D at Jefferson Lab. These data are currently being used in a large effort to calibrate the individual detector subsystems to achieve design performance. Methods and results for calibrations of each of the tracking detectors are presented. Techniques for alignment of the tracking system using a combination of cosmic rays and beam data is discussed. Finally, some early results of physics measurements including charged final-state particles are presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract DE-AC05-06OR23177.

SVGenes: a library for rendering genomic features in scalable vector graphic format.

PubMed

Etherington, Graham J; MacLean, Daniel

2013-08-01

Drawing genomic features in attractive and informative ways is a key task in visualization of genomics data. Scalable Vector Graphics (SVG) format is a modern and flexible open standard that provides advanced features including modular graphic design, advanced web interactivity and animation within a suitable client. SVGs do not suffer from loss of image quality on re-scaling and provide the ability to edit individual elements of a graphic on the whole object level independent of the whole image. These features make SVG a potentially useful format for the preparation of publication quality figures including genomic objects such as genes or sequencing coverage and for web applications that require rich user-interaction with the graphical elements. SVGenes is a Ruby-language library that uses SVG primitives to render typical genomic glyphs through a simple and flexible Ruby interface. The library implements a simple Page object that spaces and contains horizontal Track objects that in turn style, colour and positions features within them. Tracks are the level at which visual information is supplied providing the full styling capability of the SVG standard. Genomic entities like genes, transcripts and histograms are modelled in Glyph objects that are attached to a track and take advantage of SVG primitives to render the genomic features in a track as any of a selection of defined glyphs. The feature model within SVGenes is simple but flexible and not dependent on particular existing gene feature formats meaning graphics for any existing datasets can easily be created without need for conversion. The library is provided as a Ruby Gem from https://rubygems.org/gems/bio-svgenes under the MIT license, and open source code is available at https://github.com/danmaclean/bioruby-svgenes also under the MIT License. dan.maclean@tsl.ac.uk.

3D imaging of neutron tracks using confocal microscopy

NASA Astrophysics Data System (ADS)

Gillmore, Gavin; Wertheim, David; Flowers, Alan

2016-04-01

Neutron detection and neutron flux assessment are important aspects in monitoring nuclear energy production. Neutron flux measurements can also provide information on potential biological damage from exposure. In addition to the applications for neutron measurement in nuclear energy, neutron detection has been proposed as a method of enhancing neutrino detectors and cosmic ray flux has also been assessed using ground-level neutron detectors. Solid State Nuclear Track Detectors (or SSNTDs) have been used extensively to examine cosmic rays, long-lived radioactive elements, radon concentrations in buildings and the age of geological samples. Passive SSNTDs consisting of a CR-39 plastic are commonly used to measure radon because they respond to incident charged particles such as alpha particles from radon gas in air. They have a large dynamic range and a linear flux response. We have previously applied confocal microscopy to obtain 3D images of alpha particle tracks in SSNTDs from radon track monitoring (1). As a charged particle traverses through the polymer it creates an ionisation trail along its path. The trail or track is normally enhanced by chemical etching to better expose radiation damage, as the damaged area is more sensitive to the etchant than the bulk material. Particle tracks in CR-39 are usually assessed using 2D optical microscopy. In this study 6 detectors were examined using an Olympus OLS4100 LEXT 3D laser scanning confocal microscope (Olympus Corporation, Japan). The detectors had been etched for 2 hours 50 minutes at 85 °C in 6.25M NaOH. Post etch the plastics had been treated with a 10 minute immersion in a 2% acetic acid stop bath, followed by rinsing in deionised water. The detectors examined had been irradiated with a 2mSv neutron dose from an Am(Be) neutron source (producing roughly 20 tracks per mm2). We were able to successfully acquire 3D images of neutron tracks in the detectors studied. The range of track diameter observed was between 4 and 10 microns. Thus this study suggests that, using confocal microscopy, 3D imaging of neutron tracks in SSNTDs is feasible. (1) Wertheim D, Gillmore G, Brown L, Petford N. A new method of imaging particle tracks in solid state nuclear track detectors. J Microsc. 2010; 237: 1-6.

Determination of nuclear tracks parameters on sequentially etched PADC detectors

NASA Astrophysics Data System (ADS)

Horwacik, Tomasz; Bilski, Pawel; Koerner, Christine; Facius, Rainer; Berger, Thomas; Nowak, Tomasz; Reitz, Guenther; Olko, Pawel

Polyallyl Diglycol Carbonate (PADC) detectors find many applications in radiation protection. One of them is the cosmic radiation dosimetry, where PADC detectors measure the linear energy transfer (LET) spectra of charged particles (from protons to heavy ions), supplementing TLD detectors in the role of passive dosemeter. Calibration exposures to ions of known LET are required to establish a relation between parameters of track observed on the detector and LET of particle creating this track. PADC TASTRAK nuclear track detectors were exposed to 12 C and 56 Fe ions of LET in H2 O between 10 and 544 keV/µm. The exposures took place at the Heavy Ion Medical Accelerator (HIMAC) in Chiba, Japan in the frame of the HIMAC research project "Space Radiation Dosimetry-Ground Based Verification of the MATROSHKA Facility" (20P-240). Detectors were etched in water solution of NaOH with three different temperatures and for various etching times to observe the appearance of etched tracks, the evolution of their parameters and the stability of the etching process. The applied etching times (and the solution's concentrations and temperatures) were: 48, 72, 96, 120 hours (6.25 N NaOH, 50 O C), 20, 40, 60, 80 hours (6.25 N NaOH, 60 O C) and 8, 12, 16, 20 hours (7N NaOH, 70 O C). The analysis of the detectors involved planimetric (2D) measurements of tracks' entrance ellipses and mechanical measurements of bulk layer thickness. Further track parameters, like angle of incidence, track length and etch rate ratio were then calculated. For certain tracks, results of planimetric measurements and calculations were also compared with results of optical track profile (3D) measurements, where not only the track's entrance ellipse but also the location of the track's tip could be directly measured. All these measurements have been performed with the 2D/3D measurement system at DLR. The collected data allow to create sets of V(LET in H2 O) calibration curves suitable for short, intermediate and long etching time and will be use during analysis of detectors exposed on the International Space Station during DOSIS and MATROSHKA experiments. The help and support of Yukio Uchihori and Hisashi Kitamura during the irradiations at HIMAC is highly appreciated. This work was supported by the Polish Ministry of Science and Higher Education, grants: No N N505 261535 and No. DWM/N118/ESA/2008.

Effects of the lipid regulator drug gemfibrozil: A toxicological and behavioral perspective.

PubMed

Henriques, Jorge F; Almeida, Ana Rita; Andrade, Thayres; Koba, Olga; Golovko, Oksana; Soares, Amadeu M V M; Oliveira, Miguel; Domingues, Inês

2016-01-01

Pharmaceuticals are emerging contaminants as their worldwide consumption increases. Fibrates such as gemfibrozil (GEM) are used in human medicine to reduce blood concentrations of cholesterol and triacylglycerol and also are some of the most frequently reported pharmaceuticals in waste waters and surface waters. Despite some studies have already demonstrated the negative impact in physiological and/or reproductive endpoints in adult fish, data on survival and behavioral effects in fish larvae are lacking. This study aimed to assess the effects of GEM on zebrafish eleutheroembryo development and locomotor behavior. A fish embryo toxicity (FET) test was undertaken to evaluate GEM acute toxicity by exposing embryos to 0, 6.58, 9.87, 14.81, 22.22, 33.33 and 50mg/L. Developmental endpoints such as hatching success, edemas and malformations were recorded. A second test was undertaken by exposing embryos to 0, 1.5, 3 and 6mg/L in order to evaluate the effects of GEM on 120 and 144h post fertilization (hpf) larvae locomotor activity by video tracking, using a Zebrabox(®) (Viewpoint, France) device. From the data recorded, several parameters such as total swimming distance (TSD) and total swimming time (TST) in each 120s integration time were calculated. Data showed that this compound has a moderate toxic effect on fish embryo development, affecting both survival and hatching success with a calculated 96h LC50 of 11.01mg/L and no effects at the developmental level at 6mg/L. GEM seems to impair locomotor activity, even at concentrations where developmental abnormalities were unperceived, at concentrations as low as 1.5mg/L. Both TSD and TST were sensitive to GEM exposure. These effects do not seem to be independent of the developmental stage as 120hpf larvae seem to present a development bias with repercussions in locomotor behavior. This study highlights the need to include behavioral endpoints in ecotoxicological assays as this seems to be a more sensitive endpoint often disregarded. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental set up for the irradiation of biological samples and nuclear track detectors with UV C

PubMed Central

Portu, Agustina Mariana; Rossini, Andrés Eugenio; Gadan, Mario Alberto; Bernaola, Omar Alberto; Thorp, Silvia Inés; Curotto, Paula; Pozzi, Emiliano César Cayetano; Cabrini, Rómulo Luis; Martin, Gisela Saint

2016-01-01

Aim In this work we present a methodology to produce an “imprint” of cells cultivated on a polycarbonate detector by exposure of the detector to UV C radiation. Background The distribution and concentration of 10B atoms in tissue samples coming from BNCT (Boron Neutron Capture Therapy) protocols can be determined through the quantification and analysis of the tracks forming its autoradiography image on a nuclear track detector. The location of boron atoms in the cell structure could be known more accurately by the simultaneous observation of the nuclear tracks and the sample image on the detector. Materials and Methods A UV C irradiator was constructed. The irradiance was measured along the lamp direction and at different distances. Melanoma cells were cultured on polycarbonate foils, incubated with borophenylalanine, irradiated with thermal neutrons and exposed to UV C radiation. The samples were chemically attacked with a KOH solution. Results A uniform irradiation field was established to expose the detector foils to UV C light. Cells could be seeded on the polycarbonate surface. Both imprints from cells and nuclear tracks were obtained after chemical etching. Conclusions It is possible to yield cellular imprints in polycarbonate. The nuclear tracks were mostly present inside the cells, indicating a preferential boron uptake. PMID:26933396

X-ray polarization capabilities of a small explorer mission

NASA Astrophysics Data System (ADS)

Jahoda, Keith M.; Black, J. Kevin; Hill, Joanne E.; Kallman, Timothy R.; Kaaret, Philip E.; Markwardt, Craig B.; Okajima, Takashi; Petre, Robert; Soong, Yang; Strohmayer, Tod E.; Tamagawa, Toru; Tawara, Yuzuru

2014-07-01

X-ray polarization measurements hold great promise for studying the geometry and emission mechanisms in the strong gravitational and magnetic fields that surround black holes and neutron stars. In spite of this, the observational situation remains very limited; the last instrument dedicated to X-ray polarimetry flew decades ago on OSO-8, and the few recent measurements have been made by instruments optimized for other purposes. However, the technical capabilities to greatly advance the observational situation are in hand. Recent developments in micro-pattern gas detectors allow use of the polarization sensitivity of the photo-electric effect, which is the dominant interaction in the band above 2 keV. We present the scientific and technical requirements for an X-ray polarization observatory consistent with the scope of a NASA Small Explorer (SMEX) mission, along with a representative catalog of what the observational capabilities and expected sensitivities for the first year of operation could be. The mission is based on the technically robust design of the Gravity and Extreme Magnetism SMEX (GEMS) which completed a Phase B study and Preliminary Design Review in 2012. The GEMS mission is enabled by time projection detectors sensitive to the photo-electric effect. Prototype detectors have been designed, and provide engineering and performance data which support the mission design. The detectors are further characterized by low background, modest spectral resolution, and sub-millisecond timing resolution. The mission also incorporates high efficiency grazing incidence X-ray mirrors, design features that reduce systematic errors (identical telescopes at different azimuthal angles with respect to the look axis, and mounted on a rotating spacecraft platform), and a moderate capability to perform Target of Opportunity observations. The mission operates autonomously in a low earth, low inclination orbit with one to ten downlinks per day and one or more uplinks per week. Data and calibration products will be made available through the High Energy Astrophysics Science and Archival Research Center (HEASARC).

4D tracking with ultra-fast silicon detectors

NASA Astrophysics Data System (ADS)

F-W Sadrozinski, Hartmut; Seiden, Abraham; Cartiglia, Nicolò

2018-02-01

The evolution of particle detectors has always pushed the technological limit in order to provide enabling technologies to researchers in all fields of science. One archetypal example is the evolution of silicon detectors, from a system with a few channels 30 years ago, to the tens of millions of independent pixels currently used to track charged particles in all major particle physics experiments. Nowadays, silicon detectors are ubiquitous not only in research laboratories but in almost every high-tech apparatus, from portable phones to hospitals. In this contribution, we present a new direction in the evolution of silicon detectors for charge particle tracking, namely the inclusion of very accurate timing information. This enhancement of the present silicon detector paradigm is enabled by the inclusion of controlled low gain in the detector response, therefore increasing the detector output signal sufficiently to make timing measurement possible. After providing a short overview of the advantage of this new technology, we present the necessary conditions that need to be met for both sensor and readout electronics in order to achieve 4D tracking. In the last section, we present the experimental results, demonstrating the validity of our research path.

Research on application of several tracking detectors in APT system

NASA Astrophysics Data System (ADS)

Liu, Zhi

2005-01-01

APT system is the key technology in free space optical communication system, and acquisition and tracking detector is the key component in PAT system. There are several candidate detectors that can be used in PAT system, such as CCD, QAPD and CMOS Imager etc. The characteristics of these detectors are quite different, i.e., the structures and the working schemes. This paper gives thoroughly compare of the usage and working principle of CCD and CMOS imager, and discusses the key parameters like tracking error, noise analyses, power analyses etc. Conclusion is given at the end of this paper that CMOS imager is a good candidate detector for PAT system in free space optical communication system.

Application of the GEM-T2 gravity field to altimetric satellite orbit computation

NASA Technical Reports Server (NTRS)

Haines, Bruce J.; Born, George H.; Williamson, Ronald G.; Koblinsky, Chester I.

1994-01-01

As part of a continuing effort to provide improved orbits for use with existing altimeter data, we have recomputed ephemerides for both the Seasat and Geosat Exact Repeat altimeter missions. The orbits were computed in a consistent fashion, using the Goddard Earth Model T2 (GEM-T2) gravity field along with available ground-based tracking data. Such an approach allows direct comparisons of sea level between the two altimeter systems. Evaluation of the resulting ephemerides indicates that root-mean-square accuracies of 30-50 cm have been achieved for the radial component of the orbits for both satellites. An exception occurs for the last year of the Geosat Exact Repeat Mission, when the rms radial orbit accuracy degrades to the 1-m level at times owing to the inability to adequately model the drag force arising from the increased solar activity.

Image processing analysis of nuclear track parameters for CR-39 detector irradiated by thermal neutron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Jobouri, Hussain A., E-mail: hahmed54@gmail.com; Rajab, Mustafa Y., E-mail: mostafaheete@gmail.com

CR-39 detector which covered with boric acid (H{sub 3}Bo{sub 3}) pellet was irradiated by thermal neutrons from ({sup 241}Am - {sup 9}Be) source with activity 12Ci and neutron flux 10{sup 5} n. cm{sup −2}. s{sup −1}. The irradiation times -T{sub D} for detector were 4h, 8h, 16h and 24h. Chemical etching solution for detector was sodium hydroxide NaOH, 6.25N with 45 min etching time and 60 C° temperature. Images of CR-39 detector after chemical etching were taken from digital camera which connected from optical microscope. MATLAB software version 7.0 was used to image processing. The outputs of image processing of MATLABmore » software were analyzed and found the following relationships: (a) The irradiation time -T{sub D} has behavior linear relationships with following nuclear track parameters: i) total track number - N{sub T} ii) maximum track number - MRD (relative to track diameter - D{sub T}) at response region range 2.5 µm to 4 µm iii) maximum track number - M{sub D} (without depending on track diameter - D{sub T}). (b) The irradiation time -T{sub D} has behavior logarithmic relationship with maximum track number - M{sub A} (without depending on track area - A{sub T}). The image processing technique principally track diameter - D{sub T} can be take into account to classification of α-particle emitters, In addition to the contribution of these technique in preparation of nano- filters and nano-membrane in nanotechnology fields.« less

The cluster charge identification in the GEM detector for fusion plasma imaging by soft X-ray diagnostics

NASA Astrophysics Data System (ADS)

Czarski, T.; Chernyshova, M.; Malinowski, K.; Pozniak, K. T.; Kasprowicz, G.; Kolasinski, P.; Krawczyk, R.; Wojenski, A.; Zabolotny, W.

2016-11-01

The measurement system based on gas electron multiplier detector is developed for soft X-ray diagnostics of tokamak plasmas. The multi-channel setup is designed for estimation of the energy and the position distribution of an X-ray source. The focal measuring issue is the charge cluster identification by its value and position estimation. The fast and accurate mode of the serial data acquisition is applied for the dynamic plasma diagnostics. The charge clusters are counted in the space determined by 2D position, charge value, and time intervals. Radiation source characteristics are presented by histograms for a selected range of position, time intervals, and cluster charge values corresponding to the energy spectra.

The cluster charge identification in the GEM detector for fusion plasma imaging by soft X-ray diagnostics.

PubMed

Czarski, T; Chernyshova, M; Malinowski, K; Pozniak, K T; Kasprowicz, G; Kolasinski, P; Krawczyk, R; Wojenski, A; Zabolotny, W

2016-11-01

The measurement system based on gas electron multiplier detector is developed for soft X-ray diagnostics of tokamak plasmas. The multi-channel setup is designed for estimation of the energy and the position distribution of an X-ray source. The focal measuring issue is the charge cluster identification by its value and position estimation. The fast and accurate mode of the serial data acquisition is applied for the dynamic plasma diagnostics. The charge clusters are counted in the space determined by 2D position, charge value, and time intervals. Radiation source characteristics are presented by histograms for a selected range of position, time intervals, and cluster charge values corresponding to the energy spectra.

Particle Detectors

NASA Astrophysics Data System (ADS)

Grupen, Claus; Shwartz, Boris

2011-09-01

Preface to the first edition; Preface to the second edition; Introduction; 1. Interactions of particles and radiation with matter; 2. Characteristic properties of detectors; 3. Units of radiation measurements and radiation sources; 4. Accelerators; 5. Main physical phenomena used for particle detection and basic counter types; 6. Historical track detectors; 7. Track detectors; 8. Calorimetry; 9. Particle identification; 10. Neutrino detectors; 11. Momentum measurement and muon detection; 12. Ageing and radiation effects; 13. Example of a general-purpose detector: Belle; 14. Electronics; 15. Data analysis; 16. Applications of particle detectors outside particle physics; 17. Glossary; 18. Solutions; 19. Resumé; Appendixes; Index.

The ATLAS Inner Detector commissioning and calibration

DOE PAGES

Aad, G.; Abbott, B.; Abdallah, J.; ...

2010-08-20

The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7. 6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes,more » specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1±0.9 μm and a relative momentum resolution σ p/p=(4. 83 ± 0.16)×10 -4 GeV -1×p T have been measured for high momentum tracks.« less

A soft X-ray beam-splitting multilayer optic for the NASA GEMS Bragg Reflection Polarimeter

DOE PAGES

Allured, Ryan; Kaaret, Philip; Fernandez-Perea, Monica; ...

2013-04-12

A soft X-ray, beam-splitting, multilayer optic has been developed for the Bragg Reflection Polarimeter (BRP) on the NASA Gravity and Extreme Magnetism Small Explorer Mission (GEMS). The optic is designed to reflect 0.5 keV X-rays through a 90° angle to the BRP detector, and transmit 2–10 keV X-rays to the primary polarimeter. The transmission requirement prevents the use of a thick substrate, so a 2 μm thick polyimide membrane was used. Atomic force microscopy has shown the membrane to possess high spatial frequency roughness less than 0.2 nm rms, permitting adequate X-ray reflectance. A multilayer thin film was especially developedmore » and deposited via magnetron sputtering with reflectance and transmission properties that satisfy the BRP requirements and with near-zero stress. Furthermore, reflectance and transmission measurements of BRP prototype elements closely match theoretical predictions, both before and after rigorous environmental testing.« less

A soft X-ray beam-splitting multilayer optic for the NASA GEMS Bragg Reflection Polarimeter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allured, Ryan; Kaaret, Philip; Fernandez-Perea, Monica

A soft X-ray, beam-splitting, multilayer optic has been developed for the Bragg Reflection Polarimeter (BRP) on the NASA Gravity and Extreme Magnetism Small Explorer Mission (GEMS). The optic is designed to reflect 0.5 keV X-rays through a 90° angle to the BRP detector, and transmit 2–10 keV X-rays to the primary polarimeter. The transmission requirement prevents the use of a thick substrate, so a 2 μm thick polyimide membrane was used. Atomic force microscopy has shown the membrane to possess high spatial frequency roughness less than 0.2 nm rms, permitting adequate X-ray reflectance. A multilayer thin film was especially developedmore » and deposited via magnetron sputtering with reflectance and transmission properties that satisfy the BRP requirements and with near-zero stress. Furthermore, reflectance and transmission measurements of BRP prototype elements closely match theoretical predictions, both before and after rigorous environmental testing.« less

Results from the First Beam-Induced Reconstructed Tracks in the LHCb Vertex Locator

NASA Astrophysics Data System (ADS)

Rodrigues, E.

2010-04-01

LHCb is a dedicated experiment at the LHC to study CP violation and rare b decays. The vertex locator (VELO) is a silicon strip detector designed to measure precisely the production and decay vertices of B-mesons. The detector is positioned at 8 mm of the LHC beams and will operate in an extremely harsh radiation environment. The VELO consists of two retractable detector halves with 21 silicon micro-strip tracking modules each. A module is composed of two n+-on-n 300 μm thick half disc sensors with R and Φ micro-strip geometry. The detectors are operated in vacuum and a bi-phase CO2 cooling system is used. The full system has been operated since June 2008 and its commissioning experience will be reported. During the LHC synchronization tests in August and September 2008, and June 2009 the LHCb detectors measured secondary particles produced by the interaction of the LHC primary beam on a beam dump. About 50,000 tracks were reconstructed in the VELO and they were used to derive the relative timing alignment between the sensors and for the first evaluation of the spatial alignment. Using this track sample the VELO has been aligned to an accuracy of 5 μm. A single hit resolution of 10 μm was obtained at the smallest pitch for tracks of perpendicular incidence. The design and the main components of the detector system are introduced. The commissioning of the detector is reported and the talk will focus on the results obtained using the first beam-induced reconstructed tracks.

Discriminative detection of deposited radon daughters on CR-39 track detectors using TRIAC II code

NASA Astrophysics Data System (ADS)

Patiris, D. L.; Ioannides, K. G.

2009-07-01

A method for detecting deposited 218Po and 214Po by a spectrometric study of CR-39 solid state nuclear track detectors is described. The method is based on the application of software imposed selection criteria, concerning the geometrical and optical properties of the tracks, which correspond to tracks created by alpha particles of specific energy falling on the detector at given angles of incidence. The selection criteria were based on a preliminary study of tracks' parameters (major and minor axes and mean value of brightness), using the TRIAC II code. Since no linear relation was found between the energy and the geometric characteristics of the tracks (major and minor axes), we resorted to the use of an additional parameter in order to classify the tracks according to the particles' energy. Since the brightness of tracks is associated with the tracks' depth, the mean value of brightness was chosen as the parameter of choice. To reduce the energy of the particles, which are emitted by deposited 218Po and 214Po into a quantifiable range, the detectors were covered with an aluminum absorber material. In this way, the discrimination of radon's daughters was finally accomplished by properly selecting amongst all registered tracks. This method could be applied as a low cost tool for the study of the radon's daughters behavior in air.

Development of Γ-ray tracking detectors

DOE PAGES

Lieder, R. M.; Gast, W.; Jäger, H. M.; ...

2001-12-01

The next generation of 4π arrays for high-precision γ-ray spectroscopy AGATA will consist of γ-ray tracking detectors. They represent high-fold segmented Ge detectors and a front-end electronics, based on digital signal processing techniques, which allows to extract energy, timing and spatial information on the interactions of a γ-ray in the Ge detector by pulse shape analysis of its signals. Utilizing the information on the positions of the interaction points and the energies released at each point the tracks of the γ-rays in a Ge shell can be reconstructed in three dimensions on the basis of the Compton-scattering formula.

Detector Developments for the High Luminosity LHC Era (4/4)

ScienceCinema

Bortoletto, Daniela

2018-02-09

Tracking Detectors - Part II. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

Detector Developments for the High Luminosity LHC Era (3/4)

ScienceCinema

Bortoletto, Daniela

2018-01-23

Tracking Detectors - Part I. Calorimetry, muon detection, vertexing, and tracking will play a central role in determining the physics reach for the High Luminosity LHC Era. In these lectures we will cover the requirements, options, and the R&D; efforts necessary to upgrade the current LHC detectors and enabling discoveries.

Design and Construction of Detector and Data Acquisition Elements for Proton Computed Tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fermi Research Alliance; Northern Illinois University

2015-07-15

Proton computed tomography (pCT) offers an alternative to x-ray imaging with potential for three-dimensional imaging, reduced radiation exposure, and in-situ imaging. Northern Illinois University (NIU) is developing a second-generation proton computed tomography system with a goal of demonstrating the feasibility of three-dimensional imaging within clinically realistic imaging times. The second-generation pCT system is comprised of a tracking system, a calorimeter, data acquisition, a computing farm, and software algorithms. The proton beam encounters the upstream tracking detectors, the patient or phantom, the downstream tracking detectors, and a calorimeter. The schematic layout of the PCT system is shown. The data acquisition sendsmore » the proton scattering information to an offline computing farm. Major innovations of the second generation pCT project involve an increased data acquisition rate ( MHz range) and development of three-dimensional imaging algorithms. The Fermilab Particle Physics Division and Northern Illinois Center for Accelerator and Detector Development at Northern Illinois University worked together to design and construct the tracking detectors, calorimeter, readout electronics and detector mounting system.« less

Precise 3D Track Reconstruction Algorithm for the ICARUS T600 Liquid Argon Time Projection Chamber Detector

DOE PAGES

Antonello, M.; Baibussinov, B.; Benetti, P.; ...

2013-01-15

Liquid Argon Time Projection Chamber (LAr TPC) detectors offer charged particle imaging capability with remarkable spatial resolution. Precise event reconstruction procedures are critical in order to fully exploit the potential of this technology. In this paper we present a new, general approach to 3D reconstruction for the LAr TPC with a practical application to the track reconstruction. The efficiency of the method is evaluated on a sample of simulated tracks. We present also the application of the method to the analysis of stopping particle tracks collected during the ICARUS T600 detector operation with the CNGS neutrino beam.

Whole-rock uranium analysis by fission track activation

NASA Technical Reports Server (NTRS)

Weiss, J. R.; Haines, E. L.

1974-01-01

We report a whole-rock uranium method in which the polished sample and track detector are separated in a vacuum chamber. Irradiation with thermal neutrons induces uranium fission in the sample, and the detector records the integrated fission track density. Detection efficiency and geometric factors are calculated and compared with calibration experiments.

Multi-object detection and tracking technology based on hexagonal opto-electronic detector

NASA Astrophysics Data System (ADS)

Song, Yong; Hao, Qun; Li, Xiang

2008-02-01

A novel multi-object detection and tracking technology based on hexagonal opto-electronic detector is proposed, in which (1) a new hexagonal detector, which is composed of 6 linear CCDs, has been firstly developed to achieve the field of view of 360 degree, (2) to achieve the detection and tracking of multi-object with high speed, the object recognition criterions of Object Signal Width Criterion (OSWC) and Horizontal Scale Ratio Criterion (HSRC) are proposed. In this paper, Simulated Experiments have been carried out to verify the validity of the proposed technology, which show that the detection and tracking of multi-object can be achieved with high speed by using the proposed hexagonal detector and the criterions of OSWC and HSRC, indicating that the technology offers significant advantages in Photo-electric Detection, Computer Vision, Virtual Reality, Augment Reality, etc.

Prototype readout electronics and silicon strip detector study for the silicon tracking system at compressed baryonic matter experiment

NASA Astrophysics Data System (ADS)

Kasiński, Krzysztof; Szczygieł, Robert; Gryboś, Paweł

2011-10-01

This paper presents the prototype detector readout electronics for the STS (Silicon Tracking System) at CBM (Compressed Baryonic Matter) experiment at FAIR, GSI (Helmholtzzentrum fuer Schwerionenforschung GmbH) in Germany. The emphasis has been put on the strip detector readout chip and its interconnectivity with detector. Paper discusses the impact of the silicon strip detector and interconnection cable construction on the overall noise of the system and architecture of the TOT02 readout ASIC. The idea and problems of the double-sided silicon detector usage are also presented.

Event Reconstruction Techniques in NOvA

NASA Astrophysics Data System (ADS)

Baird, M.; Bian, J.; Messier, M.; Niner, E.; Rocco, D.; Sachdev, K.

2015-12-01

The NOvA experiment is a long-baseline neutrino oscillation experiment utilizing the NuMI beam generated at Fermilab. The experiment will measure the oscillations within a muon neutrino beam in a 300 ton Near Detector located underground at Fermilab and a functionally-identical 14 kiloton Far Detector placed 810 km away. The detectors are liquid scintillator tracking calorimeters with a fine-grained cellular structure that provides a wealth of information for separating the different particle track and shower topologies. Each detector has its own challenges with the Near Detector seeing multiple overlapping neutrino interactions in each event and the Far Detector having a large background of cosmic rays due to being located on the surface. A series of pattern recognition techniques have been developed to go from event records, to spatially and temporally separating individual interactions, to vertexing and tracking, and particle identification. This combination of methods to achieve the full event reconstruction will be discussed.

Centroid measurement error of CMOS detector in the presence of detector noise for inter-satellite optical communications

NASA Astrophysics Data System (ADS)

Li, Xin; Zhou, Shihong; Ma, Jing; Tan, Liying; Shen, Tao

2013-08-01

CMOS is a good candidate tracking detector for satellite optical communications systems with outstanding feature of sub-window for the development of APS (Active Pixel Sensor) technology. For inter-satellite optical communications it is critical to estimate the direction of incident laser beam precisely by measuring the centroid position of incident beam spot. The presence of detector noise results in measurement error, which degrades the tracking performance of systems. In this research, the measurement error of CMOS is derived taking consideration of detector noise. It is shown that the measurement error depends on pixel noise, size of the tracking sub-window (pixels number), intensity of incident laser beam, relative size of beam spot. The influences of these factors are analyzed by numerical simulation. We hope the results obtained in this research will be helpful in the design of CMOS detector satellite optical communications systems.

The bipolar silicon microstrip detector: A proposal for a novel precision tracking device

NASA Astrophysics Data System (ADS)

Horisberger, R.

1990-03-01

It is proposed to combine the technology of fully depleted silicon microstrip detectors fabricated on n doped high resistivity silicon with the concept of the bipolar transistor. This is done by adding a n ++ doped region inside the normal p + implanted region of the reverse biased p + n diode. Teh resulting structure has amplifying properties and is referred to as bipolar pixel transistor. The simplest readout scheme of a bipolar pixel array by an aluminium strip bus leads to the bipolar microstrip detector. The bipolar pixel structure is expected to give a better signal-to-noise performance for the detection of minimum ionizing charged particle tracks than the normal silicon diode strip detector and therefore should allow in future the fabrication of thinner silicon detectors for precision tracking.

First observations of speed of light tracks by a fluorescence detector looking down on the atmosphere

NASA Astrophysics Data System (ADS)

Abdellaoui, G.; Abe, S.; Adams, J. H., Jr.; Ahriche, A.; Allard, D.; Allen, L.; Alonso, G.; Anchordoqui, L.; Anzalone, A.; Arai, Y.; Asano, K.; Attallah, R.; Attoui, H.; Ave Pernas, M.; Bacholle, S.; Bakiri, M.; Baragatti, P.; Barrillon, P.; Bartocci, S.; Bayer, J.; Beldjilali, B.; Belenguer, T.; Belkhalfa, N.; Bellotti, R.; Belov, A.; Belov, K.; Benmessai, K.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Bisconti, F.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Bobik, P.; Bogomilov, M.; Bozzo, E.; Bruno, A.; Caballero, K. S.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Capel, F.; Caramete, A.; Caramete, L.; Carlson, P.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellina, A.; Catalano, C.; Catalano, O.; Cellino, A.; Chikawa, M.; Chiritoi, G.; Christl, M. J.; Connaughton, V.; Conti, L.; Cordero, G.; Cotto, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Cummings, A.; Dagoret-Campagne, S.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Di Martino, M.; Diaz Damian, A.; Djemil, T.; Dutan, I.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Eser, J.; Fenu, F.; Fernández-González, S.; Fernández-Soriano, J.; Ferrarese, S.; Flamini, M.; Fornaro, C.; Fouka, M.; Franceschi, A.; Franchini, S.; Fuglesang, C.; Fujii, T.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; García-Ortega, E.; Garipov, G.; Gascón, E.; Genci, J.; Giraudo, G.; González Alvarado, C.; Gorodetzky, P.; Greg, R.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Haiduc, M.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Hidber Cruz, W.; Ikeda, D.; Inoue, N.; Inoue, S.; Isgrò, F.; Itow, Y.; Jammer, T.; Jeong, S.; Joven, E.; Judd, E. G.; Jung, A.; Jochum, J.; Kajino, F.; Kajino, T.; Kalli, S.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Kedadra, A.; Khales, H.; Khrenov, B. A.; Kim, Jeong-Sook; Kim, Soon-Wook; Kleifges, M.; Klimov, P. A.; Kolev, D.; Krantz, H.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; La Barbera, A.; Lachaud, C.; Lahmar, H.; Lakhdari, F.; Larson, R.; Larsson, O.; Lee, J.; Licandro, J.; López Campano, L.; Maccarone, M. C.; Mackovjak, S.; Mahdi, M.; Maravilla, D.; Marcelli, L.; Marcos, J. L.; Marini, A.; Marszał, W.; Martens, K.; Martín, Y.; Martinez, O.; Martucci, M.; Masciantonio, G.; Mase, K.; Mastafa, M.; Matev, R.; Matthews, J. N.; Mebarki, N.; Medina-Tanco, G.; Mendoza, M. A.; Menshikov, A.; Merino, A.; Meseguer, J.; Meyer, S. S.; Mimouni, J.; Miyamoto, H.; Mizumoto, Y.; Monaco, A.; Morales de los Ríos, J. A.; Moretto, C.; Nagataki, S.; Naitamor, S.; Napolitano, T.; Naslund, W.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Pagliaro, A.; Painter, W.; Panasyuk, M. I.; Panico, B.; Pasqualino, G.; Parizot, E.; Park, I. H.; Pastircak, B.; Patzak, T.; Paul, T.; Pérez-Grande, I.; Perfetto, F.; Peter, T.; Picozza, P.; Pindado, S.; Piotrowski, L. W.; Piraino, S.; Placidi, L.; Plebaniak, Z.; Pliego, S.; Pollini, A.; Polonski, Z.; Popescu, E. M.; Prat, P.; Prévôt, G.; Prieto, H.; Puehlhofer, G.; Putis, M.; Rabanal, J.; Radu, A. A.; Reyes, M.; Rezazadeh, M.; Ricci, M.; Rodríguez Frías, M. D.; Rodencal, M.; Ronga, F.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez Cano, G.; Sagawa, H.; Sahnoune, Z.; Saito, A.; Sakaki, N.; Salazar, H.; Sanchez Balanzar, J. C.; Sánchez, J. L.; Santangelo, A.; Sanz-Andrés, A.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Spataro, B.; Stan, I.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Talai, M. C.; Tenzer, C.; Thomas, S. B.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Traïche, M.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tubbs, J.; Turriziani, S.; Uchihori, Y.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Vankova, G.; Vigorito, C.; Villaseñor, L.; Vlcek, B.; von Ballmoos, P.; Vrabel, M.; Wada, S.; Watanabe, J.; Watts, J., Jr.; Weber, M.; Weigand Muñoz, R.; Weindl, A.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, S.; Young, R.; Zgura, I. S.; Zotov, M. Yu.; Zuccaro Marchi, A.

2018-05-01

EUSO-Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It was launched on the moonless night of the 25th of August 2014 from Timmins, Canada. The flight ended successfully after maintaining the target altitude of 38 km for five hours. One part of the mission was a 2.5 hour underflight using a helicopter equipped with three UV light sources (LED, xenon flasher and laser) to perform an inflight calibration and examine the detectors capability to measure tracks moving at the speed of light. We describe the helicopter laser system and details of the underflight as well as how the laser tracks were recorded and found in the data. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. Finally, we present a first reconstruction of the direction of the laser tracks relative to the detector.

Progress in the development of a S-RETGEM-based detector for an early forest fire warning system

NASA Astrophysics Data System (ADS)

Charpak, G.; Benaben, P.; Breuil, P.; Martinengo, P.; Nappi, E.; Peskov, V.

2009-12-01

We present a prototype of a Strip Resistive Thick GEM (S-RETGEM) photosensitive gaseous detector filled with Ne and ethylferrocene (EF) vapours at a total pressure of 1 atm for an early forest fire detection system. Measurements show that it is one hundred times more sensitive than the best commercial ultraviolet (UV) flame detectors; and therefore, it is able to reliably detect a flame of ~ 1.5 × 1.5 × 1.5 m3 at a distance of about 1 km. An additional and unique feature of this detector is its imaging capability, which in combination with other techniques, may significantly reduce false fire alarms rate when operating in an automatic mode. Preliminary results conducted with air-filled photosensitive gaseous detectors are also presented. The main advantages of this approach include both the simplicity of manufacturing and affordability of construction materials such as plastics and glues specifically reducing detector production cost. The sensitivity of these air-filled detectors at certain conditions may be as high as those filled with Ne and EF. Long-term tests of such sealed detectors indicate a significant progress in this direction. We believe that our detectors utilized in addition to other flame and smoke sensors will exceptionally increase the capability to detect forest fire at a very early stage of development. Our future efforts will be focused on attempts to commercialize such detectors utilizing our aforementioned findings.

Computational steering of GEM based detector simulations

NASA Astrophysics Data System (ADS)

Sheharyar, Ali; Bouhali, Othmane

2017-10-01

Gas based detector R&D relies heavily on full simulation of detectors and their optimization before final prototypes can be built and tested. These simulations in particular those with complex scenarios such as those involving high detector voltages or gas with larger gains are computationally intensive may take several days or weeks to complete. These long-running simulations usually run on the high-performance computers in batch mode. If the results lead to unexpected behavior, then the simulation might be rerun with different parameters. However, the simulations (or jobs) may have to wait in a queue until they get a chance to run again because the supercomputer is a shared resource that maintains a queue of other user programs as well and executes them as time and priorities permit. It may result in inefficient resource utilization and increase in the turnaround time for the scientific experiment. To overcome this issue, the monitoring of the behavior of a simulation, while it is running (or live), is essential. In this work, we employ the computational steering technique by coupling the detector simulations with a visualization package named VisIt to enable the exploration of the live data as it is produced by the simulation.

Ionizing radiation measurements on LDEF: A0015 Free flyer biostack experiment

NASA Technical Reports Server (NTRS)

Benton, E. V.; Frank, A. L.; Benton, E. R.; Csige, I.; Frigo, L. A.

1995-01-01

This report covers the analysis of passive radiation detectors flown as part of the A0015 Free Flyer Biostack on LDEF (Long Duration Exposure Facility). LET (linear energy transfer) spectra and track density measurements were made with CR-39 and Polycarbonate plastic nuclear track detectors. Measurements of total absorbed dose were carried out using Thermoluminescent Detectors. Thermal and resonance neutron dose equivalents were measured with LiF/CR-39 detectors. High energy neutron and proton dose equivalents were measured with fission foil/CR-39 detectors.

The large-area hybrid-optics RICH detector for the CLAS12 spectrometer

NASA Astrophysics Data System (ADS)

Mirazita, M.; Angelini, G.; Balossino, I.; Barion, L.; Bailey, K.; Benmokhtar, F.; Brooks, W.; Cisbani, E.; Contalbrigo, M.; Cuevas, C.; Hafidi, K.; Kim, A.; Kubarovsky, V.; Lucherini, V.; Malaguti, R.; Montgomery, R.; Movsisyan, A.; Musico, P.; O'Connor, T.; Orecchini, D.; Pappalardo, L.; Perrino, R.; Pisano, S.; Raydo, B.; Rossi, P.; Squerzanti, S.; Tomassini, S.; Turisini, M.

2017-12-01

A large area imaging Cherenkov detector is under construction to provide hadron identification in the momentum range between 3 and 8 GeV/c for the CLAS12 exeperiment at the new 12 GeV electron beam of the Jefferson Laboratory (JLab). The detector adopts a hybrid optics solution with aerogel radiator, light planar and spherical mirrors and highly-segmented photon detectors. Cherenkov photons will be imaged either directly (for forward tracks) or after two mirror reflections (large angle tracks). The status of the detector construction is here reported.

Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kodaira, S., E-mail: koda@nirs.go.jp; Kurano, M.; Hosogane, T.

A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.

The cluster charge identification in the GEM detector for fusion plasma imaging by soft X-ray diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czarski, T., E-mail: tomasz.czarski@ifpilm.pl; Chernyshova, M.; Malinowski, K.

2016-11-15

The measurement system based on gas electron multiplier detector is developed for soft X-ray diagnostics of tokamak plasmas. The multi-channel setup is designed for estimation of the energy and the position distribution of an X-ray source. The focal measuring issue is the charge cluster identification by its value and position estimation. The fast and accurate mode of the serial data acquisition is applied for the dynamic plasma diagnostics. The charge clusters are counted in the space determined by 2D position, charge value, and time intervals. Radiation source characteristics are presented by histograms for a selected range of position, time intervals,more » and cluster charge values corresponding to the energy spectra.« less

Controlling alpha tracks registration in Makrofol DE 1-1 detector

NASA Astrophysics Data System (ADS)

Hassan, N. M.; Hanafy, M. S.; Naguib, A.; El-Saftawy, A. A.

2017-09-01

Makrofol DE 1-1 is a recent type of solid state nuclear track detectors could be used to measure radon concentration in the environment throughout the detection of α-particles emitted from radon decay. Thus, studying the physical parameters that control the formation of alpha tracks is vital for environmental radiation protection. Makrofol DE 1-1 polycarbonate detector was irradiated by α-particles of energies varied from 2 to 5 MeV emitted from the 241Am source of α-particle energy of 5.5 MeV. Then, the detector was etched in an optimum etching solution of mixed ethyl alcohol in KOH aqueous solution of (85% (Vol.) of 6 M KOH + 15% (Vol.) C2H5OH) at 50 °C for 3 h. Afterward, the bulk etch rate, etching sensitivity, and the registration efficiency of the detector, which control the tracks registration, were measured. The bulk etch rate of Makrofol detector was found to be 3.71 ± 0.71 μm h-1. The etching sensitivity and the detector registration efficiency were decreased exponentially with α-particles' energies following Bragg curve. A precise registration of α-particle was presented in this study. Therefore, Makrofol DE 1-1 can be applied as a radiation dosimeter as well as radon and thoron monitors.

Discharge rate measurements for Micromegas detectors in the presence of a longitudinal magnetic field

NASA Astrophysics Data System (ADS)

Moreno, B.; Aune, S.; Ball, J.; Charles, G.; Giganon, A.; Konczykowski, P.; Lahonde-Hamdoun, C.; Moutarde, H.; Procureur, S.; Sabatié, F.

2011-10-01

We present first discharge rate measurements for Micromegas detectors in the presence of a high longitudinal magnetic field in the GeV kinematical region. Measurements were performed by using two Micromegas detectors and a photon beam impinging a CH 2 target in the Hall B of the Jefferson Laboratory. One detector was equipped with an additional GEM foil, and a reduction of the discharge probability by two orders of magnitude compared to the stand-alone Micromegas was observed. The detectors were placed in the FROST solenoid providing a longitudinal magnetic field up to 5 T. It allowed for precise measurements of the discharge probability dependence with a diffusion-reducing magnetic field. Between 0 and 5 T, the discharge probability increased by a factor of 10 for polar angles between 19° and 34°. A GEANT4-based simulation developed for sparking rate calculation was calibrated against these data in order to predict the sparking rate in a high longitudinal magnetic field environment. This simulation is then used to investigate the possible use of Micromegas in the Forward Vertex Tracker (FVT) of the future CLAS12 spectrometer. In the case of the FVT a sparking rate of 1 Hz per detector was obtained at the anticipated CLAS12 luminosity.

On the consistency among different approaches for nuclear track scanning and data processing

NASA Astrophysics Data System (ADS)

Inozemtsev, K. O.; Kushin, V. V.; Kodaira, S.; Shurshakov, V. A.

2018-04-01

The article describes various approaches for space radiation track measurement using CR-39™ detector (Tastrak). The results of comparing different methods for track scanning and data processing are presented. Basic algorithms for determination of track parameters are described. Every approach involves individual set of measured track parameters. For two sets, track scanning is sufficient in the plane of detector surface (2-D measurement), third set requires scanning in the additional projection (3-D measurement). An experimental comparison of considered techniques was made with the use of accelerated heavy ions Ar, Fe and Kr.

Nanoscale measurements of proton tracks using fluorescent nuclear track detectors

PubMed Central

Sawakuchi, Gabriel O.; Ferreira, Felisberto A.; McFadden, Conor H.; Hallacy, Timothy M.; Granville, Dal A.; Sahoo, Narayan; Akselrod, Mark S.

2016-01-01

Purpose: The authors describe a method in which fluorescence nuclear track detectors (FNTDs), novel track detectors with nanoscale spatial resolution, are used to determine the linear energy transfer (LET) of individual proton tracks from proton therapy beams by allowing visualization and 3D reconstruction of such tracks. Methods: FNTDs were exposed to proton therapy beams with nominal energies ranging from 100 to 250 MeV. Proton track images were then recorded by confocal microscopy of the FNTDs. Proton tracks in the FNTD images were fit by using a Gaussian function to extract fluorescence amplitudes. Histograms of fluorescence amplitudes were then compared with LET spectra. Results: The authors successfully used FNTDs to register individual proton tracks from high-energy proton therapy beams, allowing reconstruction of 3D images of proton tracks along with delta rays. The track amplitudes from FNTDs could be used to parameterize LET spectra, allowing the LET of individual proton tracks from therapeutic proton beams to be determined. Conclusions: FNTDs can be used to directly visualize proton tracks and their delta rays at the nanoscale level. Because the track intensities in the FNTDs correlate with LET, they could be used further to measure LET of individual proton tracks. This method may be useful for measuring nanoscale radiation quantities and for measuring the LET of individual proton tracks in radiation biology experiments. PMID:27147359

Nanoscale measurements of proton tracks using fluorescent nuclear track detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sawakuchi, Gabriel O., E-mail: gsawakuchi@mdanderson.org; Sahoo, Narayan; Ferreira, Felisberto A.

Purpose: The authors describe a method in which fluorescence nuclear track detectors (FNTDs), novel track detectors with nanoscale spatial resolution, are used to determine the linear energy transfer (LET) of individual proton tracks from proton therapy beams by allowing visualization and 3D reconstruction of such tracks. Methods: FNTDs were exposed to proton therapy beams with nominal energies ranging from 100 to 250 MeV. Proton track images were then recorded by confocal microscopy of the FNTDs. Proton tracks in the FNTD images were fit by using a Gaussian function to extract fluorescence amplitudes. Histograms of fluorescence amplitudes were then compared withmore » LET spectra. Results: The authors successfully used FNTDs to register individual proton tracks from high-energy proton therapy beams, allowing reconstruction of 3D images of proton tracks along with delta rays. The track amplitudes from FNTDs could be used to parameterize LET spectra, allowing the LET of individual proton tracks from therapeutic proton beams to be determined. Conclusions: FNTDs can be used to directly visualize proton tracks and their delta rays at the nanoscale level. Because the track intensities in the FNTDs correlate with LET, they could be used further to measure LET of individual proton tracks. This method may be useful for measuring nanoscale radiation quantities and for measuring the LET of individual proton tracks in radiation biology experiments.« less

Automatic methods of the processing of data from track detectors on the basis of the PAVICOM facility

NASA Astrophysics Data System (ADS)

Aleksandrov, A. B.; Goncharova, L. A.; Davydov, D. A.; Publichenko, P. A.; Roganova, T. M.; Polukhina, N. G.; Feinberg, E. L.

2007-02-01

New automatic methods essentially simplify and increase the rate of the processing of data from track detectors. This provides a possibility of processing large data arrays and considerably improves their statistical significance. This fact predetermines the development of new experiments which plan to use large-volume targets, large-area emulsion, and solid-state track detectors [1]. In this regard, the problem of training qualified physicists who are capable of operating modern automatic equipment is very important. Annually, about ten Moscow students master the new methods, working at the Lebedev Physical Institute at the PAVICOM facility [2 4]. Most students specializing in high-energy physics are only given an idea of archaic manual methods of the processing of data from track detectors. In 2005, on the basis of the PAVICOM facility and the physicstraining course of Moscow State University, a new training work was prepared. This work is devoted to the determination of the energy of neutrons passing through a nuclear emulsion. It provides the possibility of acquiring basic practical skills of the processing of data from track detectors using automatic equipment and can be included in the educational process of students of any physical faculty. Those who have mastered the methods of automatic data processing in a simple and pictorial example of track detectors will be able to apply their knowledge in various fields of science and technique. Formulation of training works for pregraduate and graduate students is a new additional aspect of application of the PAVICOM facility described earlier in [4].

AN ALTERNATIVE CALIBRATION OF CR-39 DETECTORS FOR RADON DETECTION BEYOND THE SATURATION LIMIT.

PubMed

Franci, Daniele; Aureli, Tommaso; Cardellini, Francesco

2016-12-01

Time-integrated measurements of indoor radon levels are commonly carried out using solid-state nuclear track detectors (SSNTDs), due to the numerous advantages offered by this radiation detection technique. However, the use of SSNTD also presents some problems that may affect the accuracy of the results. The effect of overlapping tracks often results in the underestimation of the detected track density, which leads to the reduction of the counting efficiency for increasing radon exposure. This article aims to address the effect of overlapping tracks by proposing an alternative calibration technique based on the measurement of the fraction of the detector surface covered by alpha tracks. The method has been tested against a set of Monte Carlo data and then applied to a set of experimental data collected at the radon chamber of the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, at the ENEA centre in Casaccia, using CR-39 detectors. It has been proved that the method allows to extend the detectable range of radon exposure far beyond the intrinsic limit imposed by the standard calibration based on the track density. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Geographically correlated orbit error

NASA Technical Reports Server (NTRS)

Rosborough, G. W.

1989-01-01

The dominant error source in estimating the orbital position of a satellite from ground based tracking data is the modeling of the Earth's gravity field. The resulting orbit error due to gravity field model errors are predominantly long wavelength in nature. This results in an orbit error signature that is strongly correlated over distances on the size of ocean basins. Anderle and Hoskin (1977) have shown that the orbit error along a given ground track also is correlated to some degree with the orbit error along adjacent ground tracks. This cross track correlation is verified here and is found to be significant out to nearly 1000 kilometers in the case of TOPEX/POSEIDON when using the GEM-T1 gravity model. Finally, it was determined that even the orbit error at points where ascending and descending ground traces cross is somewhat correlated. The implication of these various correlations is that the orbit error due to gravity error is geographically correlated. Such correlations have direct implications when using altimetry to recover oceanographic signals.

Isotopic Composition of Gaseous Elemental Mercury in the Free Troposphere of the Pic du Midi Observatory, France.

PubMed

Fu, Xuewu; Marusczak, Nicolas; Wang, Xun; Gheusi, François; Sonke, Jeroen E

2016-06-07

Understanding the sources and transformations of mercury (Hg) in the free troposphere is a critical aspect of global Hg research. Here we present one year of observations of atmospheric Hg speciation and gaseous elemental Hg (GEM) isotopic composition at the high-altitude Pic du Midi Observatory (2860 m above sea level) in France. Biweekly integrated GEM from February 2012 to January 2013 revealed significant variations in δ(202)HgGEM (-0.04‰ to 0.52‰) but not in Δ(199)HgGEM (-0.17‰ to -0.27‰) or Δ(200)HgGEM (-0.10‰ to 0.05‰). δ(202)HgGEM was negatively correlated with CO and reflected air mass origins from Europe (high CO, low δ(202)HgGEM) and from the Atlantic Ocean (low CO, high δ(202)HgGEM). We suggest that the δ(202)HgGEM variations represent mixing of recent low δ(202)HgGEM European anthropogenic emissions with high δ(202)HgGEM northern hemispheric background GEM. In addition, Atlantic Ocean free troposphere air masses showed a positive correlation between δ(202)HgGEM and gaseous oxidized Hg (GOM) concentrations, indicative of mass-dependent Hg isotope fractionation during GEM oxidation. On the basis of atmospheric δ(202)HgGEM and speciated Hg observations, we suggest that the oceanic free troposphere is a reservoir within which GEM is readily oxidized to GOM.

Engineering cell-fluorescent ion track hybrid detectors.

PubMed

Niklas, Martin; Greilich, Steffen; Melzig, Claudius; Akselrod, Mark S; Debus, Jürgen; Jäkel, Oliver; Abdollahi, Amir

2013-06-11

The lack of sensitive biocompatible particle track detectors has so far limited parallel detection of physical energy deposition and biological response. Fluorescent nuclear track detectors (FNTDs) based on Al₂O₃:C,Mg single crystals combined with confocal laser scanning microscopy (CLSM) provide 3D information on ion tracks with a resolution limited by light diffraction. Here we report the development of next generation cell-fluorescent ion track hybrid detectors (Cell-Fit-HD). The biocompatibility of FNTDs was tested using six different cell lines, i.e. human non-small cell lung carcinoma (A549), glioblastoma (U87), androgen independent prostate cancer (PC3), epidermoid cancer (A431) and murine (VmDk) glioma SMA-560. To evaluate cell adherence, viability and conformal coverage of the crystals different seeding densities and alternative coating with extracellular matrix (fibronectin) was tested. Carbon irradiation was performed in Bragg peak (initial 270.55 MeV u⁻¹). A series of cell compartment specific fluorescence stains including nuclear (HOECHST), membrane (Glut-1), cytoplasm (Calcein AM, CM-DiI) were tested on Cell-Fit-HDs and a single CLSM was employed to co-detect the physical (crystal) as well as the biological (cell layer) information. The FNTD provides a biocompatible surface. Among the cells tested, A549 cells formed the most uniform, viable, tightly packed epithelial like monolayer. The ion track information was not compromised in Cell-Fit-HD as compared to the FNTD alone. Neither cell coating and culturing, nor additional staining procedures affected the properties of the FNTD surface to detect ion tracks. Standard immunofluorescence and live staining procedures could be employed to co-register cell biology and ion track information. The Cell-Fit-Hybrid Detector system is a promising platform for a multitude of studies linking biological response to energy deposition at high level of optical microscopy resolution.

Cosmic ray particle dosimetry and trajectory tracing. [cosmic ray track analysis for Apollo 17 BIOCORE

NASA Technical Reports Server (NTRS)

Cruty, M. R.; Benton, E. V.; Turnbill, C. E.; Philpott, D. E.

1975-01-01

Five pocket mice (Perognathus longimembris) were flown on Apollo XVII, each with a solid-state (plastic) nuclear track detector implanted beneath its scalp. The subscalp detectors were sensitive to HZE cosmic ray particles with a LET greater than or approximately equal to 0.15 million electron volts per micrometer (MeV/micron). A critical aspect of the dosimetry of the experiment involved tracing individual particle trajectories through each mouse head from particle tracks registered in the individual subscalp detectors, thereby establishing a one-to-one correspondence between a trajectory location in the tissue and the presence or absence of a lesion. The other major aspect was the identification of each registered particle. An average of 16 particles with Z greater than or equal to 6 and 2.2 particles with Z greater than or equal to 20 were found per detector. The track density, 29 tracks/sq cm, when adjusted for detection volume, was in agreement with the photographic emulsion data from an area dosimeter located next to the flight package.

Lateral distributions of EAS muons (Eμ > 800 MeV) measured with the KASCADE-Grande Muon Tracking Detector in the primary energy range 1016 -1017 eV

NASA Astrophysics Data System (ADS)

Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

2015-05-01

The KASCADE-Grande large area (128 m2) Muon Tracking Detector has been built with the aim to identify muons ( Eμthr = 800 MeV) in Extensive Air Showers by track measurements under 18 r.l. shielding. This detector provides high-accuracy angular information (approx. 0.3 °) for muons up to 700 m distance from the shower core. In this work we present the lateral density distributions of muons in EAS measured with the Muon Tracking Detector of the KASCADE-Grande experiment. The density is calculated by counting muon tracks in a muon-to-shower-axis distance range from 100 m to 610 m from showers with reconstructed energy of 1016 -1017 eV and zenith angle θ < 18 ° . In the distance range covered by the experiment, these distributions are well described by functions phenomenologically determined already in the fifties (of the last century) by Greisen. They are compared also with the distributions obtained with the KASCADE scintillator array (Eμthr = 230 MeV) and with distributions obtained using simulated showers.

Monte Carlo Evaluation of a New Track-Finding Method for the VENUS Muon Detector

NASA Astrophysics Data System (ADS)

Asano, Yuzo; Hatanaka, Makoto; Koseki, Tadashi; Mori, Shigeki; Shirakata, Masashi; Yamamoto, Kazumichi

1989-10-01

A new method of finding a track is devised for the VENUS muon detector composed of eight-cell drift-tube modules, each cell having a rectangular cross section of 5× 7 cm2. The new method, in which fourth-order equations are solved by the Ferarri-Cardano method, is especially powerful for a track having a large incident angle with respect to the line normal to the anode-wire plane of a drift tube, compared to the presently used method in which a track is determined by the intersecting points of an equi-drift-distance circle and the anode-wire plane. Cosmic-ray test data for the forward-backward part muon detector support these simulation results.

Comparison of different detection methods for persistent multiple hypothesis tracking in wide area motion imagery

NASA Astrophysics Data System (ADS)

Hartung, Christine; Spraul, Raphael; Schuchert, Tobias

2017-10-01

Wide area motion imagery (WAMI) acquired by an airborne multicamera sensor enables continuous monitoring of large urban areas. Each image can cover regions of several square kilometers and contain thousands of vehicles. Reliable vehicle tracking in this imagery is an important prerequisite for surveillance tasks, but remains challenging due to low frame rate and small object size. Most WAMI tracking approaches rely on moving object detections generated by frame differencing or background subtraction. These detection methods fail when objects slow down or stop. Recent approaches for persistent tracking compensate for missing motion detections by combining a detection-based tracker with a second tracker based on appearance or local context. In order to avoid the additional complexity introduced by combining two trackers, we employ an alternative single tracker framework that is based on multiple hypothesis tracking and recovers missing motion detections with a classifierbased detector. We integrate an appearance-based similarity measure, merge handling, vehicle-collision tests, and clutter handling to adapt the approach to the specific context of WAMI tracking. We apply the tracking framework on a region of interest of the publicly available WPAFB 2009 dataset for quantitative evaluation; a comparison to other persistent WAMI trackers demonstrates state of the art performance of the proposed approach. Furthermore, we analyze in detail the impact of different object detection methods and detector settings on the quality of the output tracking results. For this purpose, we choose four different motion-based detection methods that vary in detection performance and computation time to generate the input detections. As detector parameters can be adjusted to achieve different precision and recall performance, we combine each detection method with different detector settings that yield (1) high precision and low recall, (2) high recall and low precision, and (3) best f-score. Comparing the tracking performance achieved with all generated sets of input detections allows us to quantify the sensitivity of the tracker to different types of detector errors and to derive recommendations for detector and parameter choice.

The use of integrated focal plane array technologies in laser microsatellite networks

NASA Astrophysics Data System (ADS)

Arnon, Shlomi

2004-10-01

Clustering micro satellites in cooperative fly formation constellations leads to high-performance space systems. The only way to achieve high-speed communication between the satellites is by a laser beam with a narrow divergence angle. In order to make the communication successful three types of focal plane detector arrays are required in the communication terminal: acquisition, tracking and communication detector arrays. The acquisition detector array is used to acquire the neighbor satellite using a wide field-of-view telescope. The tracking detector provides fast, real time and accurate direction location of the neighbor satellite. Based on the information from the acquisition and tracking detectors the receiver and transmitter maintain line of sight. The development of large, fast and very sensitive focal plane detector arrays makes it possible to implement the acquisition, tracking and communication with only one focal plane detector array. By doing so it is possible to reduce dramatically the size, weight, and cost of the optics and electronics which leads to lightweight communication terminals. As a result, the satellites are smaller and lighter, which reduces the space mission cost and increases the booster efficiency. In this paper we will present an overview of the concept of integrated focal plane arrays for laser satellite communication. We also present simulation results based on real system parameters and compare different implementation options.

Assessing alternatives for directional detection of a halo of weakly interacting massive particles

NASA Astrophysics Data System (ADS)

Copi, Craig J.; Krauss, Lawrence M.; Simmons-Duffin, David; Stroiney, Steven R.

2007-01-01

The future of direct terrestrial WIMP detection lies on two fronts: new, much larger low background detectors sensitive to energy deposition, and detectors with directional sensitivity. The former can explore a large range of WIMP parameter space using well-tested technology while the latter may be necessary if one is to disentangle particle physics parameters from astrophysical halo parameters. Because directional detectors will be quite difficult to construct it is worthwhile exploring in advance generally which experimental features will yield the greatest benefits at the lowest costs. We examine the sensitivity of directional detectors with varying angular tracking resolution with and without the ability to distinguish forward versus backward recoils, and compare these to the sensitivity of a detector where the track is projected onto a two-dimensional plane. The latter detector regardless of where it is placed on the Earth, can be oriented to produce a significantly better discrimination signal than a 3D detector without this capability, and with sensitivity within a factor of 2 of a full 3D tracking detector. Required event rates to distinguish signals from backgrounds for a simple isothermal halo range from the low teens in the best case to many thousands in the worst.

The GTP binding proteins Gem and Rad are negative regulators of the Rho–Rho kinase pathway

PubMed Central

Ward, Yvona; Yap, Seow-Fong; Ravichandran, V.; Matsumura, Fumio; Ito, Masaaki; Spinelli, Beth; Kelly, Kathleen

2002-01-01

The cytoskeletal changes that alter cellular morphogenesis and motility depend upon a complex interplay among molecules that regulate actin, myosin, and other cytoskeletal components. The Rho family of GTP binding proteins are important upstream mediators of cytoskeletal organization. Gem and Rad are members of another family of small GTP binding proteins (the Rad, Gem, and Kir family) for which biochemical functions have been mostly unknown. Here we show that Gem and Rad interface with the Rho pathway through association with the Rho effectors, Rho kinase (ROK) α and β. Gem binds ROKβ independently of RhoA in the ROKβ coiled-coil region adjacent to the Rho binding domain. Expression of Gem inhibited ROKβ-mediated phosphorylation of myosin light chain and myosin phosphatase, but not LIM kinase, suggesting that Gem acts by modifying the substrate specificity of ROKβ. Gem or Rad expression led to cell flattening and neurite extension in N1E-115 neuroblastoma cells. In interference assays, Gem opposed ROKβ- and Rad opposed ROKα-mediated cell rounding and neurite retraction. Gem did not oppose cell rounding initiated by ROKβ containing a deletion of the Gem binding region, demonstrating that Gem binding to ROKβ is required for the effects observed. In epithelial or fibroblastic cells, Gem or Rad expression resulted in stress fiber and focal adhesion disassembly. In addition, Gem reverted the anchorage-independent growth and invasiveness of Dbl-transformed fibroblasts. These results identify physiological roles for Gem and Rad in cytoskeletal regulation mediated by ROK. PMID:11956230

Detectors for Linear Colliders: Tracking and Vertexing (2/4)

ScienceCinema

Battaglia, Marco

2018-04-16

Efficient and precise determination of the flavour of partons in multi-hadron final states is essential to the anticipated LC physics program. This makes tracking in the vicinity of the interaction region of great importance. Tracking extrapolation and momentum resolution are specified by precise physics requirements. The R&D; towards detectors able to meet these specifications will be discussed, together with some of their application beyond particle physics.

Detection limit of a VCO based detection chain dedicated to particles recognition and tracking

NASA Astrophysics Data System (ADS)

Coulié, K.; Rahajandraibe, W.; Aziza, H.; Micolau, G.; Vauché, R.

2018-01-01

A particle detection chain based on CMOS-SOI VCO circuit is presented. The solution is used for the recognition and the tracking of a given particle at circuit level. TCAD simulation of the detector has been performed on a 3×3 matrix of diodes based detector for particles recognition and tracking. The current response of the detector has been used for a case study in order to determine the ability of the chain to recognize an alpha particle crossing a 3×3 detection cell. The detection limit of the proposed solution is investigated and discussed in this paper.

Shipborne measurements of mercury in the marine boundary layer

NASA Astrophysics Data System (ADS)

Soerensen, A. L.; Skov, H.; Christensen, J.; Glasius, M.; Soerensen, B. T.; Steffen, A.; Jensen, B.; Christoffersen, C.; Madsen, H. W.; Johnson, M. S.

2008-12-01

Mercury accumulates in the human body, for example when consumed through fish and other aquatic animals. While it is poisonous to adults, only low doses are sufficient to cause severe effects in the development of foetuses where the source of mercury is through the mother's blood. From once being a problem restricted to certain populations, the negative effects of mercury consumption are becoming a global problem due to high anthropogenic emissions, long range transport in the atmosphere and bioaccumulation in the food chain after deposition. It is therefore important to understand the atmospheric photochemical pathways of mercury from source to sink. We have used a TEKRAN 2537A mercury vapor analyzer with a TEKRAN 1130 mercury speciation unit to measure gaseous elemental mercury (GEM) and reactive gaseous mercury (RGM) during an eight month circumnavigation of the Earth. This is the longest single track time series of mercury concentrations that we know of. This has offered the opportunity to give a global overview of the marine boundary layer (MBL) distribution of both GEM and RGM. Supplemented with earlier cruise measurements, we now have a broader knowledge of global GEM and RGM concentration in the MBL. The Galathea 3 cruise data offers new knowledge of the mechanisms causing the distribution patterns of GEM and RGM in the MBL. The first analysis of the Galathea 3 data indicates that measurements show a concentration difference between the northern and the southern hemispheres. In the northern hemisphere, the mean concentration in the free ocean is 2.06 ng/m3 and, including values down wind of Western Europe, an average value of 2.47 ng/m3 was found. Measurements in the southern hemisphere show a mean concentration of 1.24 ng/m3 and 1.57 ng/m3 where values close to the coast of West Africa are included. In contrast, the concentration levels of RGM are similar for the two hemispheres (northern hemisphere 3.40 pg/m3, southern hemisphere 3.95 pg/m3). Some interesting events involving coastal influence where observed during the cruise. For example, along the coast of Antarctica GEM and RGM peaked simultaneously with some of the highest observed concentrations of RGM during the cruise. Along the west coast of South Africa measurements of GEM were observed up to 10.16 ng/m3 with a mean of 5.17 ng/m3 between the 10th and 15th of November 2006.

Gemcitabine-based polymer-drug conjugate for enhanced anticancer effect in colon cancer.

PubMed

Liang, Tie-Jun; Zhou, Zhong-Mei; Cao, Ying-Qing; Ma, Ming-Ze; Wang, Xiao-Jun; Jing, Kai

2016-11-20

In this study, we have demonstrated gemcitabine (GEM)-conjugated amphiphilic biodegradable polymeric drug carriers. Our aim was to increase the chemotherapeutic potential of GEM in colon cancer by forming a unique polymer-drug conjugates. The polymer-drug conjugate micelles were nanosized with a typical spherical shape. The GEM-conjugated methoxy poly(ethylene glycol)-poly(lactic acid) (GEM-PL) exhibited a controlled release of drug in both the pH conditions. The developed GEM-PL efficiently killed the HT29 cancers cells in a typical time dependent manner. The clonogenic assay further confirmed the superior anticancer effect of GEM-PL which showed least number of colonies. GEM-PL formulation exhibited a significantly higher apoptosis of cancer cells (∼25%) when stained using Annexin-V/PI kit. Conjugation of GEM to the mPEG-PLA significantly enhanced the blood circulation potential in animal model compared to that of free GEM. GEM-PL could prevent quick elimination of the drug and can provide sufficient time for the greater accumulation of GEM at the tumor sites. GEM-PL showed a remarkable tumor regression effect as evident from the lowest tumor volume in HT-29 containing tumor model. Overall, mPEG-PLA/GEM conjugates showed the potential of polymer-based drug targeting and might hold significant clinical potential in the treatment of colon cancers. Copyright © 2016 Elsevier B.V. All rights reserved.

Solid State Nuclear Track Detectors--I: Track Characteristics and Formation Mechanisms.

ERIC Educational Resources Information Center

Lal, Nand

1991-01-01

Heavily ionizing charged particles produce radiation damage tracks in a wide variety of insulating materials. The experimental properties of these tracks and track recorders are described. The mechanisms by which the tracks are produced are discussed. (Author/KR)

Trends and new developments in gaseous detectors

NASA Astrophysics Data System (ADS)

Hoch, M.

Almost one century ago the method of particle detection with gaseous detectors was invented. Since then they have been exploited successfully in many experiments using a wide variety of different applications. The development is still going on today. The underlying working principles are today well understood and with the help of modern simulation techniques, new configurations can be easily examined and optimized before a first experimental test. Traditional wire chamber ensembles demonstrate that they are still up to date and are well prepared to meet also the challenges of LHC. Applications will be discussed using TPCs in high multiplicity environments with standard Multi-Wire Proportional Chamber (MWPC) as readout as well as drift tubes in a muon spectrometer for a Large Hardron Collider (LHC) experiment. Triggered by the evolving printed circuit technology, a new generation of gaseous detectors with very high position resolution and rate capability has emerged. Two representatives (MICROMEGAS, GEM) have proved their reliability in various experiments and are promising candidates for future projects. Performance and results will be discussed for these detectors. Furthermore, achievements in RPC-based detectors will be discussed. The standard Trigger RPC is a reliable low-cost semi-industrial manufactured device with good time resolution. Thin gap RPCs (Multigap-, and High Rate Timing RPC) show very fast signal response at high efficiency and significantly increased rate capability and will be applied in TOF detectors.

A fast 1-D detector for imaging and time resolved SAXS experiments

NASA Astrophysics Data System (ADS)

Menk, R. H.; Arfelli, F.; Bernstorff, S.; Pontoni, D.; Sarvestani, A.; Besch, H. J.; Walenta, A. H.

1999-02-01

A one-dimensional test detector on the principle of a highly segmented ionization chamber with shielding grid (Frisch grid) was developed to evaluate if this kind of detector is suitable for advanced small-angle X-ray scattering (SAXS) experiments. At present it consists of 128 pixels which can be read out within 0.2 ms with a noise floor of 2000 e-ENC. A quantum efficiency of 80% for a photon energy of 8 keV was achieved. This leads to DQE values of 80% for photon fluxes above 1000 photons/pixel and integration time. The shielding grid is based on the principles of the recently invented MCAT structure and the GEM structure which also allows electron amplification in the gas. In the case of the MCAT structure, an energy resolution of 20% at 5.9 keV was observed. The gas amplification mode enables imaging with this integrating detector on a subphoton noise level with respect to the integration time. Preliminary experiments of saturation behavior show that this kind of detector digests a photon flux density up to 10 12 photons/mm 2 s and operates linearly. A spatial resolution of at least three line pairs/mm was obtained. All these features show that this type of detector is well suited for time-resolved SAXS experiments as well as high flux imaging applications.

GEM1: First-year modeling and IT activities for the Global Earthquake Model

NASA Astrophysics Data System (ADS)

Anderson, G.; Giardini, D.; Wiemer, S.

2009-04-01

GEM is a public-private partnership initiated by the Organisation for Economic Cooperation and Development (OECD) to build an independent standard for modeling and communicating earthquake risk worldwide. GEM is aimed at providing authoritative, open information about seismic risk and decision tools to support mitigation. GEM will also raise risk awareness and help post-disaster economic development, with the ultimate goal of reducing the toll of future earthquakes. GEM will provide a unified set of seismic hazard, risk, and loss modeling tools based on a common global IT infrastructure and consensus standards. These tools, systems, and standards will be developed in partnership with organizations around the world, with coordination by the GEM Secretariat and its Secretary General. GEM partners will develop a variety of global components, including a unified earthquake catalog, fault database, and ground motion prediction equations. To ensure broad representation and community acceptance, GEM will include local knowledge in all modeling activities, incorporate existing detailed models where possible, and independently test all resulting tools and models. When completed in five years, GEM will have a versatile, penly accessible modeling environment that can be updated as necessary, and will provide the global standard for seismic hazard, risk, and loss models to government ministers, scientists and engineers, financial institutions, and the public worldwide. GEM is now underway with key support provided by private sponsors (Munich Reinsurance Company, Zurich Financial Services, AIR Worldwide Corporation, and Willis Group Holdings); countries including Belgium, Germany, Italy, Singapore, Switzerland, and Turkey; and groups such as the European Commission. The GEM Secretariat has been selected by the OECD and will be hosted at the Eucentre at the University of Pavia in Italy; the Secretariat is now formalizing the creation of the GEM Foundation. Some of GEM's global components are in the planning stages, such as the developments of a unified active fault database and earthquake catalog. The flagship activity of GEM's first year is GEM1, a focused pilot project to develop GEM's first hazard and risk modeling products and initial IT infrastructure, starting in January 2009 and ending in March 2010. GEM1 will provide core capabilities for the present and key knowledge for future development of the full GEM computing Environment and product set. We will build GEM1 largely using existing tools and datasets, connected through a unified IT infrastructure, in order to bring GEM's initial capabilities online as rapidly as possible. The Swiss Seismological Service at ETH-Zurich is leading the GEM1 effort in cooperation with partners around the world. We anticipate that GEM1's products will include: • A global compilation of regional seismic source zone models in one or more common representations • Global synthetic earthquake catalogs for use in hazard calculations • Initial set of regional and global catalogues for validation • Global hazard models in map and database forms • First compilation of global vulnerabilities and fragilities • Tools for exposure and loss assessment • Validation of results and software for existing risk assessment tools to be used in future GEM stages • Demonstration risk scenarios for target cities • First version of GEM IT infrastructure All these products will be made freely available to the greatest extent possible. For more information on GEM and GEM1, please visit http://www.globalquakemodel.org.

A fast method for optical simulation of flood maps of light-sharing detector modules.

PubMed

Shi, Han; Du, Dong; Xu, JianFeng; Moses, William W; Peng, Qiyu

2015-12-01

Optical simulation of the detector module level is highly desired for Position Emission Tomography (PET) system design. Commonly used simulation toolkits such as GATE are not efficient in the optical simulation of detector modules with complicated light-sharing configurations, where a vast amount of photons need to be tracked. We present a fast approach based on a simplified specular reflectance model and a structured light-tracking algorithm to speed up the photon tracking in detector modules constructed with polished finish and specular reflector materials. We simulated conventional block detector designs with different slotted light guide patterns using the new approach and compared the outcomes with those from GATE simulations. While the two approaches generated comparable flood maps, the new approach was more than 200-600 times faster. The new approach has also been validated by constructing a prototype detector and comparing the simulated flood map with the experimental flood map. The experimental flood map has nearly uniformly distributed spots similar to those in the simulated flood map. In conclusion, the new approach provides a fast and reliable simulation tool for assisting in the development of light-sharing-based detector modules with a polished surface finish and using specular reflector materials.

Low material budget floating strip Micromegas for ion transmission radiography

NASA Astrophysics Data System (ADS)

Bortfeldt, J.; Biebel, O.; Flierl, B.; Hertenberger, R.; Klitzner, F.; Lösel, Ph.; Magallanes, L.; Müller, R.; Parodi, K.; Schlüter, T.; Voss, B.; Zibell, A.

2017-02-01

Floating strip Micromegas are high-accuracy and discharge insensitive gaseous detectors, able to track single particles at fluxes of 7 MHz/cm2 with 100 μm resolution. We developed low-material-budget detectors with one-dimensional strip readout, suitable for tracking at highest particle rates as encountered in medical ion transmission radiography or inner tracker applications. Recently we additionally developed Kapton-based floating strip Micromegas with two-dimensional strip readout, featuring an overall thickness of 0.011 X0. These detectors were tested in high-rate proton and carbon-ion beams at the tandem accelerator in Garching and the Heidelberg Ion-Beam Therapy Center, operated with an optimized Ne:CF4 gas mixture. By coupling the Micromegas detectors to a new scintillator based range detector, ion transmission radiographies of PMMA and tissue-equivalent phantoms were acquired. The range detector with 18 layers is read out via wavelength shifting fibers, coupled to a multi-anode photomultiplier. We present the performance of the Micromegas detectors with respect to timing and single plane track reconstruction using the μTPC method. We discuss the range resolution of the scintillator range telescope and present the image reconstruction capabilities of the combined system.

Towards an Optimal Interest Point Detector for Measurements in Ultrasound Images

NASA Astrophysics Data System (ADS)

Zukal, Martin; Beneš, Radek; Číka, Petr; Říha, Kamil

2013-12-01

This paper focuses on the comparison of different interest point detectors and their utilization for measurements in ultrasound (US) images. Certain medical examinations are based on speckle tracking which strongly relies on features that can be reliably tracked frame to frame. Only significant features (interest points) resistant to noise and brightness changes within US images are suitable for accurate long-lasting tracking. We compare three interest point detectors - Harris-Laplace, Difference of Gaussian (DoG) and Fast Hessian - and identify the most suitable one for use in US images on the basis of an objective criterion. Repeatability rate is assumed to be an objective quality measure for comparison. We have measured repeatability in images corrupted by different types of noise (speckle noise, Gaussian noise) and for changes in brightness. The Harris-Laplace detector outperformed its competitors and seems to be a sound option when choosing a suitable interest point detector for US images. However, it has to be noted that Fast Hessian and DoG detectors achieved better results in terms of processing speed.

Development of a cylindrical tracking detector with multichannel scintillation fibers and pixelated photon detector readout

NASA Astrophysics Data System (ADS)

Akazawa, Y.; Miwa, K.; Honda, R.; Shiozaki, T.; Chiga, N.

2015-07-01

We are developing a cylindrical tracking detector for a Σp scattering experiment in J-PARC with scintillation fibers and the Pixelated Photon Detector (PPD) readout, which is called as cylindrical fiber tracker (CFT), in order to reconstruct trajectories of charged particles emitted inside CFT. CFT works not only as a tracking detector but also a particle identification detector from energy deposits. A prototype CFT consisting of two straight layers and one spiral layer was constructed. About 1100 scintillation fibers with a diameter of 0.75 mm (Kuraray SCSF-78 M) were used. Each fiber signal was read by Multi-Pixel Photon Counter (MPPC, HPK S10362-11-050P, 1×1 mm2, 400 pixels) fiber by fiber. MPPCs were handled with Extended Analogue Silicon Photomultipliers Integrated ReadOut Chip (EASIROC) boards, which were developed for the readout of a large number of MPPCs. The energy resolution of one layer was 28% for a 70 MeV proton where the energy deposit in fibers was 0.7 MeV.

System and method for tracking a signal source. [employing feedback control

NASA Technical Reports Server (NTRS)

Mogavero, L. N.; Johnson, E. G.; Evans, J. M., Jr.; Albus, J. S. (Inventor)

1978-01-01

A system for tracking moving signal sources is disclosed which is particularly adaptable for use in tracking stage performers. A miniature transmitter is attached to the person or object to be tracked and emits a detectable signal of a predetermined frequency. A plurality of detectors positioned in a preset pattern sense the signal and supply output information to a phase detector which applies signals representing the angular orientation of the transmitter to a computer. The computer provides command signals to a servo network which drives a device such as a motor driven mirror reflecting the beam of a spotlight, to track the moving transmitter.

Assessing alternatives for directional detection of a halo of weakly interacting massive particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Copi, Craig J.; Krauss, Lawrence M.; Department of Astronomy, Case Western Reserve University, 10900 Euclid Ave., Cleveland, Ohio 44106-7079

2007-01-15

The future of direct terrestrial WIMP detection lies on two fronts: new, much larger low background detectors sensitive to energy deposition, and detectors with directional sensitivity. The former can explore a large range of WIMP parameter space using well-tested technology while the latter may be necessary if one is to disentangle particle physics parameters from astrophysical halo parameters. Because directional detectors will be quite difficult to construct it is worthwhile exploring in advance generally which experimental features will yield the greatest benefits at the lowest costs. We examine the sensitivity of directional detectors with varying angular tracking resolution with andmore » without the ability to distinguish forward versus backward recoils, and compare these to the sensitivity of a detector where the track is projected onto a two-dimensional plane. The latter detector regardless of where it is placed on the Earth, can be oriented to produce a significantly better discrimination signal than a 3D detector without this capability, and with sensitivity within a factor of 2 of a full 3D tracking detector. Required event rates to distinguish signals from backgrounds for a simple isothermal halo range from the low teens in the best case to many thousands in the worst.« less

Track reconstruction in the inhomogeneous magnetic field for Vertex Detector of NA61/SHINE experiment at CERN SPS

NASA Astrophysics Data System (ADS)

Merzlaya, Anastasia; NA61/SHINE Collaboration

2017-01-01

The heavy-ion programme of the NA61/SHINE experiment at CERN SPS is expanding to allow precise measurements of exotic particles with lifetime few hundred microns. A Vertex Detector for open charm measurements at the SPS is being constructed by the NA61/SHINE Collaboration to meet the challenges of high spatial resolution of secondary vertices and efficiency of track registration. This task is solved by the application of the coordinate sensitive CMOS Monolithic Active Pixel Sensors with extremely low material budget in the new Vertex Detector. A small-acceptance version of the Vertex Detector is being tested this year, later it will be expanded to a large-acceptance version. Simulation studies will be presented. A method of track reconstruction in the inhomogeneous magnetic field for the Vertex Detector was developed and implemented. Numerical calculations show the possibility of high precision measurements in heavy ion collisions of strange and multi strange particles, as well as heavy flavours, like charmed particles.

The readout chain for the bar PANDA MVD strip detector

NASA Astrophysics Data System (ADS)

Schnell, R.; Brinkmann, K.-Th.; Di Pietro, V.; Kleines, H.; Goerres, A.; Riccardi, A.; Rivetti, A.; Rolo, M. D.; Sohlbach, H.; Zaunick, H.-G.

2015-02-01

The bar PANDA (antiProton ANnihilation at DArmstadt) experiment will study the strong interaction in annihilation reactions between an antiproton beam and a stationary gas jet target. The detector will comprise different sub-detectors for tracking, particle identification and calorimetry. The Micro-Vertex Detector (MVD) as the innermost part of the tracking system will allow precise tracking and detection of secondary vertices. For the readout of the double-sided silicon strip sensors a custom-made ASIC is being developed, employing the Time-over-Threshold (ToT) technique for digitization and utilize time-to-digital converters (TDC) to provide a high-precision time stamp of the hit. A custom-made Module Data Concentrator ASIC (MDC) will multiplex the data of all front-ends of one sensor towards the CERN-developed GBT chip set (GigaBit Transceiver). The MicroTCA-based MVD Multiplexer Board (MMB) at the off-detector site will receive and concentrate the data from the GBT links and transfer it to FPGA-based compute nodes for global event building.

Test beam performance measurements for the Phase I upgrade of the CMS pixel detector

NASA Astrophysics Data System (ADS)

Dragicevic, M.; Friedl, M.; Hrubec, J.; Steininger, H.; Gädda, A.; Härkönen, J.; Lampén, T.; Luukka, P.; Peltola, T.; Tuominen, E.; Tuovinen, E.; Winkler, A.; Eerola, P.; Tuuva, T.; Baulieu, G.; Boudoul, G.; Caponetto, L.; Combaret, C.; Contardo, D.; Dupasquier, T.; Gallbit, G.; Lumb, N.; Mirabito, L.; Perries, S.; Vander Donckt, M.; Viret, S.; Bonnin, C.; Charles, L.; Gross, L.; Hosselet, J.; Tromson, D.; Feld, L.; Karpinski, W.; Klein, K.; Lipinski, M.; Pierschel, G.; Preuten, M.; Rauch, M.; Wlochal, M.; Aldaya, M.; Asawatangtrakuldee, C.; Beernaert, K.; Bertsche, D.; Contreras-Campana, C.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Gallo, E.; Garay Garcia, J.; Hansen, K.; Haranko, M.; Harb, A.; Hauk, J.; Keaveney, J.; Kalogeropoulos, A.; Kleinwort, C.; Lohmann, W.; Mankel, R.; Maser, H.; Mittag, G.; Muhl, C.; Mussgiller, A.; Pitzl, D.; Reichelt, O.; Savitskyi, M.; Schütze, P.; Sola, V.; Spannagel, S.; Walsh, R.; Zuber, A.; Biskop, H.; Buhmann, P.; Centis-Vignali, M.; Garutti, E.; Haller, J.; Hoffmann, M.; Klanner, R.; Lapsien, T.; Matysek, M.; Perieanu, A.; Scharf, Ch.; Schleper, P.; Schmidt, A.; Schwandt, J.; Sonneveld, J.; Steinbrück, G.; Vormwald, B.; Wellhausen, J.; Abbas, M.; Amstutz, C.; Barvich, T.; Barth, Ch.; Boegelspacher, F.; De Boer, W.; Butz, E.; Casele, M.; Colombo, F.; Dierlamm, A.; Freund, B.; Hartmann, F.; Heindl, S.; Husemann, U.; Kornmeyer, A.; Kudella, S.; Muller, Th.; Simonis, H. J.; Steck, P.; Weber, M.; Weiler, Th.; Kiss, T.; Siklér, F.; Tölyhi, T.; Veszprémi, V.; Cariola, P.; Creanza, D.; De Palma, M.; De Robertis, G.; Fiore, L.; Franco, M.; Loddo, F.; Sala, G.; Silvestris, L.; Maggi, G.; My, S.; Selvaggi, G.; Albergo, S.; Cappello, G.; Costa, S.; Di Mattia, A.; Giordano, F.; Potenza, R.; Saizu, M. A.; Tricomi, A.; Tuve, C.; Focardi, E.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Malvezzi, S.; Manzoni, R. A.; Menasce, D.; Moroni, L.; Pedrini, D.; Azzi, P.; Bacchetta, N.; Bisello, D.; Dall'Osso, M.; Pozzobon, N.; Tosi, M.; Alunni Solestizi, L.; Biasini, M.; Bilei, G. M.; Cecchi, C.; Checcucci, B.; Ciangottini, D.; Fanò, L.; Gentsos, C.; Ionica, M.; Leonardi, R.; Manoni, E.; Mantovani, G.; Marconi, S.; Mariani, V.; Menichelli, M.; Modak, A.; Morozzi, A.; Moscatelli, F.; Passeri, D.; Placidi, P.; Postolache, V.; Rossi, A.; Saha, A.; Santocchia, A.; Storchi, L.; Spiga, D.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Basti, A.; Boccali, T.; Borrello, L.; Bosi, F.; Castaldi, R.; Ceccanti, M.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Magazzu, G.; Mammini, P.; Mariani, F.; Mazzoni, E.; Messineo, A.; Moggi, A.; Morsani, F.; Palla, F.; Palmonari, F.; Profeti, A.; Raffaelli, F.; Ragonesi, A.; Rizzi, A.; Soldani, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Abbaneo, D.; Ahmed, I.; Albert, E.; Auzinger, G.; Berruti, G.; Bonnaud, J.; Daguin, J.; D'Auria, A.; Detraz, S.; Dondelewski, O.; Engegaard, B.; Faccio, F.; Frank, N.; Gill, K.; Honma, A.; Kornmayer, A.; Labaza, A.; Manolescu, F.; McGill, I.; Mersi, S.; Michelis, S.; Onnela, A.; Ostrega, M.; Pavis, S.; Peisert, A.; Pernot, J.-F.; Petagna, P.; Postema, H.; Rapacz, K.; Sigaud, C.; Tropea, P.; Troska, J.; Tsirou, A.; Vasey, F.; Verlaat, B.; Vichoudis, P.; Zwalinski, L.; Bachmair, F.; Becker, R.; di Calafiori, D.; Casal, B.; Berger, P.; Djambazov, L.; Donega, M.; Grab, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meinhard, M.; Perozzi, L.; Roeser, U.; Starodumov, A.; Tavolaro, V.; Wallny, R.; Zhu, D.; Amsler, C.; Bösiger, K.; Caminada, L.; Canelli, F.; Chiochia, V.; de Cosa, A.; Galloni, C.; Hreus, T.; Kilminster, B.; Lange, C.; Maier, R.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Taroni, S.; Yang, Y.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Kaestli, H.-C.; Kotlinski, D.; Langenegger, U.; Meier, B.; Rohe, T.; Streuli, S.; Chen, P.-H.; Dietz, C.; Fiori, F.; Grundler, U.; Hou, W.-S.; Lu, R.-S.; Moya, M.; Tsai, J.-F.; Tzeng, Y. M.; Cussans, D.; Goldstein, J.; Grimes, M.; Newbold, D.; Hobson, P.; Reid, I. D.; Auzinger, G.; Bainbridge, R.; Dauncey, P.; Hall, G.; James, T.; Magnan, A.-M.; Pesaresi, M.; Raymond, D. M.; Uchida, K.; Durkin, T.; Harder, K.; Shepherd-Themistocleous, C.; Chertok, M.; Conway, J.; Conway, R.; Flores, C.; Lander, R.; Pellett, D.; Ricci-Tam, F.; Squires, M.; Thomson, J.; Yohay, R.; Burt, K.; Ellison, J.; Hanson, G.; Olmedo, M.; Si, W.; Yates, B. R.; Dominguez, A.; Bartek, R.; Bentele, B.; Cumalat, J. P.; Ford, W. T.; Jensen, F.; Johnson, A.; Krohn, M.; Leontsinis, S.; Mulholland, T.; Stenson, K.; Wagner, S. R.; Apresyan, A.; Bolla, G.; Burkett, K.; Butler, J. N.; Canepa, A.; Cheung, H. W. K.; Christian, D.; Cooper, W. E.; Deptuch, G.; Derylo, G.; Gingu, C.; Grünendahl, S.; Hasegawa, S.; Hoff, J.; Howell, J.; Hrycyk, M.; Jindariani, S.; Johnson, M.; Kahlid, F.; Kwan, S.; Lei, C. M.; Lipton, R.; Lopes De Sá, R.; Liu, T.; Los, S.; Matulik, M.; Merkel, P.; Nahn, S.; Prosser, A.; Rivera, R.; Schneider, B.; Sellberg, G.; Shenai, A.; Siehl, K.; Spiegel, L.; Tran, N.; Uplegger, L.; Voirin, E.; Berry, D. R.; Chen, X.; Ennesser, L.; Evdokimov, A.; Gerber, C. E.; Makauda, S.; Mills, C.; Sandoval Gonzalez, I. D.; Alimena, J.; Antonelli, L. J.; Francis, B.; Hart, A.; Hill, C. S.; Parashar, N.; Stupak, J.; Bortoletto, D.; Bubna, M.; Hinton, N.; Jones, M.; Miller, D. H.; Shi, X.; Baringer, P.; Bean, A.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Schmitz, E.; Wilson, G.; Ivanov, A.; Mendis, R.; Mitchell, T.; Skhirtladze, N.; Taylor, R.; Anderson, I.; Fehling, D.; Gritsan, A.; Maksimovic, P.; Martin, C.; Nash, K.; Osherson, M.; Swartz, M.; Xiao, M.; Acosta, J. G.; Cremaldi, L. M.; Oliveros, S.; Perera, L.; Summers, D.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Gonzalez Suarez, R.; Monroy, J.; Siado, J.; Bartz, E.; Gershtein, Y.; Halkiadakis, E.; Kyriacou, S.; Lath, A.; Nash, K.; Osherson, M.; Schnetzer, S.; Stone, R.; Walker, M.; Malik, S.; Norberg, S.; Ramirez Vargas, J. E.; Alyari, M.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Kharchilava, A.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; McDermott, K.; Mirman, N.; Rinkevicius, A.; Ryd, A.; Salvati, E.; Skinnari, L.; Soffi, L.; Tao, Z.; Thom, J.; Tucker, J.; Zientek, M.; Akgün, B.; Ecklund, K. M.; Kilpatrick, M.; Nussbaum, T.; Zabel, J.; D'Angelo, P.; Johns, W.; Rose, K.; Choudhury, S.; Korol, I.; Seitz, C.; Vargas Trevino, A.; Dolinska, G.

2017-05-01

A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase I Upgrade of the LHC . The new CMS pixel detector provides four-hit tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. In this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency is 99.95 ± 0.05%, while the intrinsic spatial resolutions are 4.80 ± 0.25 μm and 7.99 ± 0.21 μm along the 100 μm and 150 μm pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.

The Gem GTP-binding protein promotes morphological differentiation in neuroblastoma.

PubMed

Leone, A; Mitsiades, N; Ward, Y; Spinelli, B; Poulaki, V; Tsokos, M; Kelly, K

2001-05-31

Gem is a small GTP-binding protein within the Ras superfamily whose function has not been determined. We report here that ectopic Gem expression is sufficient to stimulate cell flattening and neurite extension in N1E-115 and SH-SY5Y neuroblastoma cells, suggesting a role for Gem in cytoskeletal rearrangement and/or morphological differentiation of neurons. Consistent with this potential function, in clinical samples of neuroblastoma, Gem protein was most highly expressed within cells which had differentiated to express ganglionic morphology. Gem was also observed in developing trigeminal nerve ganglia in 12.5 day mouse embryos, demonstrating that Gem expression is a property of normal ganglionic development. Although Gem expression is rare in epithelial and hematopoietic cancer cell lines, constitutive Gem levels were detected in several neuroblastoma cell lines and could be further induced as much as 10-fold following treatment with PMA or the acetylcholine muscarinic agonist, carbachol.

A Large Tracking Detector In Vacuum Consisting Of Self-Supporting Straw Tubes

NASA Astrophysics Data System (ADS)

Wintz, P.

2004-02-01

A novel technique to stretch the anode wire simply by the gas over-pressure inside straw drift tubes reduces the necessary straw weight to an absolute minimum. Our detector will consist of more than 3000 straws filling up a cylindrical tracking volume of 1m diameter and 30cm length. The projected spatial resolution is 200μm. The detector with a total mass of less than 15kg will be operated in vacuum, but will have an added wall thickness of 3mm mylar, only. The detector design, production experience and first results will be discussed.

The artificial retina for track reconstruction at the LHC crossing rate

NASA Astrophysics Data System (ADS)

Abba, A.; Bedeschi, F.; Citterio, M.; Caponio, F.; Cusimano, A.; Geraci, A.; Marino, P.; Morello, M. J.; Neri, N.; Punzi, G.; Piucci, A.; Ristori, L.; Spinella, F.; Stracka, S.; Tonelli, D.

2016-04-01

We present the results of an R&D study for a specialized processor capable of precisely reconstructing events with hundreds of charged-particle tracks in pixel and silicon strip detectors at 40 MHz, thus suitable for processing LHC events at the full crossing frequency. For this purpose we design and test a massively parallel pattern-recognition algorithm, inspired to the current understanding of the mechanisms adopted by the primary visual cortex of mammals in the early stages of visual-information processing. The detailed geometry and charged-particle's activity of a large tracking detector are simulated and used to assess the performance of the artificial retina algorithm. We find that high-quality tracking in large detectors is possible with sub-microsecond latencies when the algorithm is implemented in modern, high-speed, high-bandwidth FPGA devices.

Microdosimetry and Katz's track structure theory. I. One-hit detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zaider, M.

1990-10-01

A microdosimetric treatment of the response of one-hit detectors to radiation is formulated and compared with the model proposed by R. Katz, S. C. Sharma, and M. Homayoonfar within the framework of their track-structure theory. It is shown that radial dose distributions (on which the track structure theory is based) are generally poor substitutes for the exact microdosimetric distributions except when (a) the target is much larger than the radial extent of the track or (b) the effective specific energy in the target (alpha z) is negligibly small. Since neither one of these conditions is generally satisfied, it is suggestedmore » that a meaningful search for one-hit detectors be based on a microdosimetric description of the stochastics of energy deposition. An analysis of the phi x-174 bacteriophage inactivation data is presented.« less

Tracking the NOvA Detectors' Performance

NASA Astrophysics Data System (ADS)

Psihas, Fernanda; NOvA Collaboration

2016-03-01

The NOvA experiment measures long baseline νμ -->νe oscillations in Fermilab's NuMI beam. We employ two detectors equipped with over 10 thousand sets of data-taking electronics; avalanche photo diodes and front end boards which collect and process the scintillation signal from particle interactions within the detectors. These sets of electronics -as well as the systems which power and cool them- must be monitored and maintained at precise working conditions to ensure maximal data-taking uptime, good data quality and a lasting life for our detectors. This poster describes the automated systems used on NOvA to simultaneously monitor our data quality, diagnose hardware issues, track our performance and coordinate maintenance for the detectors.

Effects of etching time on alpha tracks in solid state nuclear track detectors.

PubMed

Gillmore, Gavin; Wertheim, David; Crust, Simon

2017-01-01

Solid State Nuclear Track Detectors (SSNTDs) are used extensively for monitoring alpha particle radiation, neutron flux and cosmic ray radiation. Radon gas inhalation is regarded as being a significant contributory factor to lung cancer deaths in the UK each year. Gas concentrations are often monitored using CR39 based SSNTDs as the natural decay of radon results in alpha particles which form tracks in these detectors. Such tracks are normally etched for about 4h to enable microscopic analysis. This study examined the effect of etching time on the appearance of alpha tracks in SSNTDs by collecting 2D and 3D image datasets using laser confocal microscope imaging techniques. Etching times of 2 to 4h were compared and marked differences were noted in resultant track area. The median equivalent diameters of tracks were 20.2, 30.2 and 38.9μm for etching at 2, 3 and 4h respectively. Our results indicate that modern microscope imaging can detect and image the smaller size tracks seen for example at 3h etching time. Shorter etching times may give rise to fewer coalescing tracks although there is a balance to consider as smaller track sizes may be more difficult to image. Thus etching for periods of less than 4h clearly merits further investigation as this approach has the potential to improve accuracy in assessing the number of tracks. Copyright © 2016 Elsevier B.V. All rights reserved.

Engineering cell-fluorescent ion track hybrid detectors

PubMed Central

2013-01-01

Background The lack of sensitive biocompatible particle track detectors has so far limited parallel detection of physical energy deposition and biological response. Fluorescent nuclear track detectors (FNTDs) based on Al2O3:C,Mg single crystals combined with confocal laser scanning microscopy (CLSM) provide 3D information on ion tracks with a resolution limited by light diffraction. Here we report the development of next generation cell-fluorescent ion track hybrid detectors (Cell-Fit-HD). Methods The biocompatibility of FNTDs was tested using six different cell lines, i.e. human non-small cell lung carcinoma (A549), glioblastoma (U87), androgen independent prostate cancer (PC3), epidermoid cancer (A431) and murine (VmDk) glioma SMA-560. To evaluate cell adherence, viability and conformal coverage of the crystals different seeding densities and alternative coating with extracellular matrix (fibronectin) was tested. Carbon irradiation was performed in Bragg peak (initial 270.55 MeV u−1). A series of cell compartment specific fluorescence stains including nuclear (HOECHST), membrane (Glut-1), cytoplasm (Calcein AM, CM-DiI) were tested on Cell-Fit-HDs and a single CLSM was employed to co-detect the physical (crystal) as well as the biological (cell layer) information. Results The FNTD provides a biocompatible surface. Among the cells tested, A549 cells formed the most uniform, viable, tightly packed epithelial like monolayer. The ion track information was not compromised in Cell-Fit-HD as compared to the FNTD alone. Neither cell coating and culturing, nor additional staining procedures affected the properties of the FNTD surface to detect ion tracks. Standard immunofluorescence and live staining procedures could be employed to co-register cell biology and ion track information. Conclusions The Cell-Fit-Hybrid Detector system is a promising platform for a multitude of studies linking biological response to energy deposition at high level of optical microscopy resolution. PMID:23758749

TrackEtching - A Java based code for etched track profile calculations in SSNTDs

NASA Astrophysics Data System (ADS)

Muraleedhara Varier, K.; Sankar, V.; Gangadathan, M. P.

2017-09-01

A java code incorporating a user friendly GUI has been developed to calculate the parameters of chemically etched track profiles of ion-irradiated solid state nuclear track detectors. Huygen's construction of wavefronts based on secondary wavelets has been used to numerically calculate the etched track profile as a function of the etching time. Provision for normal incidence and oblique incidence on the detector surface has been incorporated. Results in typical cases are presented and compared with experimental data. Different expressions for the variation of track etch rate as a function of the ion energy have been utilized. The best set of values of the parameters in the expressions can be obtained by comparing with available experimental data. Critical angle for track development can also be calculated using the present code.

A novel approach to Hough Transform for implementation in fast triggers

NASA Astrophysics Data System (ADS)

Pozzobon, Nicola; Montecassiano, Fabio; Zotto, Pierluigi

2016-10-01

Telescopes of position sensitive detectors are common layouts in charged particles tracking, and programmable logic devices, such as FPGAs, represent a viable choice for the real-time reconstruction of track segments in such detector arrays. A compact implementation of the Hough Transform for fast triggers in High Energy Physics, exploiting a parameter reduction method, is proposed, targeting the reduction of the needed storage or computing resources in current, or next future, state-of-the-art FPGA devices, while retaining high resolution over a wide range of track parameters. The proposed approach is compared to a Standard Hough Transform with particular emphasis on their application to muon detectors. In both cases, an original readout implementation is modeled.

Lasercom system architecture with reduced complexity

NASA Technical Reports Server (NTRS)

Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homayoon (Inventor)

1994-01-01

Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention, a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides the means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

LaserCom System Architecture With Reduced Complexity

NASA Technical Reports Server (NTRS)

Lesh, James R. (Inventor); Chen, Chien-Chung (Inventor); Ansari, Homa-Yoon (Inventor)

1996-01-01

Spatial acquisition and precision beam pointing functions are critical to spaceborne laser communication systems. In the present invention a single high bandwidth CCD detector is used to perform both spatial acquisition and tracking functions. Compared to previous lasercom hardware design, the array tracking concept offers reduced system complexity by reducing the number of optical elements in the design. Specifically, the design requires only one detector and one beam steering mechanism. It also provides means to optically close the point-ahead control loop. The technology required for high bandwidth array tracking was examined and shown to be consistent with current state of the art. The single detector design can lead to a significantly reduced system complexity and a lower system cost.

Autonomous space target recognition and tracking approach using star sensors based on a Kalman filter.

PubMed

Ye, Tao; Zhou, Fuqiang

2015-04-10

When imaged by detectors, space targets (including satellites and debris) and background stars have similar point-spread functions, and both objects appear to change as detectors track targets. Therefore, traditional tracking methods cannot separate targets from stars and cannot directly recognize targets in 2D images. Consequently, we propose an autonomous space target recognition and tracking approach using a star sensor technique and a Kalman filter (KF). A two-step method for subpixel-scale detection of star objects (including stars and targets) is developed, and the combination of the star sensor technique and a KF is used to track targets. The experimental results show that the proposed method is adequate for autonomously recognizing and tracking space targets.

Not Your Ordinary GEM

NASA Technical Reports Server (NTRS)

2001-01-01

Through Small Business Innovation Research (SBIR) funding from NASA's Stennis Space Center, Geophex devised a new design for broadband electromagnetic sensors. Geophex developed a patented sensing technology, capable not only of coastal monitoring, but also a variety of other functions, including environmental pollution characterization, groundwater contamination detection, archaeological study, and mineral detection. The new technology is offered in several of the company's products the GEM-2, GEM-2A, and the GEM-3. The Geophex products consist of two primary electromagnetic coils, which are stimulated by alternating currents that generate a magnetic field in the object targeted for investigation. GEM-2 is a handheld, lightweight, programmable, digital device. GEM-2A is an airborne version of the sensor. Suspended from a helicopter, the GEM-2A is used to search for mineral deposits and to survey large tracts of land. The GEM-3 is capable of detecting buried landmines and other active munitions. GEM-3 identifies landmines by their brand names. Because each landmine has its own unique electromagnetic response to the broad frequency band emitted by the GEM-3, bomb identification and disposal strategies are made easier.

Origins of GEMS Grains

NASA Technical Reports Server (NTRS)

Messenger, S.; Walker, R. M.

2012-01-01

Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the chemical compositions of GEMS grains are extremely heterogeneous and seem to rule out this possibility. Based on their solar isotopic compositions and their non-solar elemental compositions we propose that most GEMS grains formed in the nebula as late-stage non-equilibrium condensates.

Geophysical Monitoring Station (GEMS)

NASA Astrophysics Data System (ADS)

Banerdt, B.; Dehant, V. M.; Lognonne, P.; Smrekar, S. E.; Spohn, T.; GEMS Mission Team

2011-12-01

GEMS (GEophysical Monitoring Station) is one of three missions undergoing Phase A development for possible selection by NASA's Discovery Program. If selected, GEMS will perform the first comprehensive surface-based geophysical investigation of Mars, filling a longstanding gap in the scientific exploration of the solar system. It will illuminate the fundamental processes of terrestrial planet formation and evolution, providing unique and critical information about the initial accretion of the planet, the formation and differentiation of the core and crust, and the subsequent evolution of the interior. The scientific goals of GEMS are to understand the formation and evolution of terrestrial planets through investigation of the interior structure and processes of Mars and to determine its present level of tectonic activity and impact flux. A straightforward set of scientific objectives address these goals: 1) Determine the size, composition and physical state of the core; 2) Determine the thickness and structure of the crust; 3) Determine the composition and structure of the mantle; 4) Determine the thermal state of the interior; 5) Measure the rate and distribution of internal seismic activity; and 6) Measure the rate of impacts on the surface. To accomplish these objectives, GEMS carries a tightly-focused payload consisting of 3 investigations: 1) SEIS, a 6-component, very-broad-band seismometer, with careful thermal compensation/control and a sensitivity comparable to the best terrestrial instruments across a frequency range of 1 mHz to 50 Hz; 2) HP3 (Heat Flow and Physical Properties Package), an instrumented self-penetrating mole system that trails a string of temperature sensors to measure the thermal gradient and conductivity of the upper several meters, and thus the planetary heat flux; and 3) RISE (Rotation and Interior Structure Experiment), which would use the spacecraft X-band communication system to provide precision tracking for planetary dynamical studies. The two instruments are moved from the lander deck to the martian surface by an Instrument Deployment Arm, with an appropriate location identified using an Instrument Deployment Camera. In order to ensure low risk within the tight Discovery cost limits, GEMS reuses the successful Lockheed Martin Phoenix spacecraft design, with a cruise and EDL system that has demonstrated capability for safe landing on Mars with well-understood costs. To take full advantage of this approach, all science requirements (such as instrument mass and power, landing site, and downlinked data volume) strictly conform to existing, demonstrated capabilities of the spacecraft and mission system. It is widely believed that multiple landers making simultaneous measurements (a network) are required to address the objectives for understanding terrestrial planet interiors. Nonetheless, comprehensive measurements from a single geophysical station are extremely valuable, because observations constraining the structure and processes of the deep interior of Mars are virtually nonexistent. GEMS would utilize sophisticated analysis techniques specific to single-station measurements to determine crustal thickness, mantle structure, core state and size, and heat flow, providing our first real look deep beneath the surface of Mars.

Monopole track characteristics in plastic detectors

NASA Technical Reports Server (NTRS)

Ahlen, S. P.

1975-01-01

Total and restricted energy loss rates were calculated for magnetic monopoles of charge g = 137 e in Lexan polycarbonate. Range-energy curves are also presented. The restricted energy loss model is used to estimate the appearance of a monopole track in plastic detectors. These results should be useful for the design and analysis of monopole experiments.

Long-term object tracking combined offline with online learning

NASA Astrophysics Data System (ADS)

Hu, Mengjie; Wei, Zhenzhong; Zhang, Guangjun

2016-04-01

We propose a simple yet effective method for long-term object tracking. Different from the traditional visual tracking method, which mainly depends on frame-to-frame correspondence, we combine high-level semantic information with low-level correspondences. Our framework is formulated in a confidence selection framework, which allows our system to recover from drift and partly deal with occlusion. To summarize, our algorithm can be roughly decomposed into an initialization stage and a tracking stage. In the initialization stage, an offline detector is trained to get the object appearance information at the category level, which is used for detecting the potential target and initializing the tracking stage. The tracking stage consists of three modules: the online tracking module, detection module, and decision module. A pretrained detector is used for maintaining drift of the online tracker, while the online tracker is used for filtering out false positive detections. A confidence selection mechanism is proposed to optimize the object location based on the online tracker and detection. If the target is lost, the pretrained detector is utilized to reinitialize the whole algorithm when the target is relocated. During experiments, we evaluate our method on several challenging video sequences, and it demonstrates huge improvement compared with detection and online tracking only.

Data management software concept for WEST plasma measurement system

NASA Astrophysics Data System (ADS)

Zienkiewicz, P.; Kasprowicz, G.; Byszuk, A.; Wojeński, A.; Kolasinski, P.; Cieszewski, R.; Czarski, T.; Chernyshova, M.; Pozniak, K.; Zabolotny, W.; Juszczyk, B.; Mazon, D.; Malard, P.

2014-11-01

This paper describes the concept of data management software for the multichannel readout system for the GEM detector used in WEST Plasma experiment. The proposed system consists of three separate communication channels: fast data channel, diagnostics channel, slow data channel. Fast data channel is provided by the FPGA with integrated ARM cores providing direct readout data from Analog Front Ends through 10GbE with short, guaranteed intervals. Slow data channel is provided by multiple, fast CPUs after data processing with detailed readout data with use of GNU/Linux OS and appropriate software. Diagnostic channel provides detailed feedback for control purposes.

Monte-Carlo Estimation of the Inflight Performance of the GEMS Satellite X-Ray Polarimeter

NASA Technical Reports Server (NTRS)

Kitaguchi, Takao; Tamagawa, Toru; Hayato, Asami; Enoto, Teruaki; Yoshikawa, Akifumi; Kaneko, Kenta; Takeuchi, Yoko; Black, Kevin; Hill, Joanne; Jahoda, Keith;

Monte-Carlo estimation of the inflight performance of the GEMS satellite x-ray polarimeter

NASA Astrophysics Data System (ADS)

Kitaguchi, Takao; Tamagawa, Toru; Hayato, Asami; Enoto, Teruaki; Yoshikawa, Akifumi; Kaneko, Kenta; Takeuchi, Yoko; Black, Kevin; Hill, Joanne; Jahoda, Keith; Krizmanic, John; Sturner, Steven; Griffiths, Scott; Kaaret, Philip; Marlowe, Hannah

2014-07-01

We report a Monte-Carlo estimation of the in-orbit performance of a cosmic X-ray polarimeter designed to be installed on the focal plane of a small satellite. The simulation uses GEANT for the transport of photons and energetic particles and results from Magboltz for the transport of secondary electrons in the detector gas. We validated the simulation by comparing spectra and modulation curves with actual data taken with radioactive sources and an X-ray generator. We also estimated the in-orbit background induced by cosmic radiation in low Earth orbit.

CDF-II and B physics

NASA Astrophysics Data System (ADS)

Lockyer, Nigel S.

1998-02-01

This paper reports on the CDF-II B physics goals and new detector systems presently being built for Run-II of the Tevatron collider in the year 2000. The B physics goals are focused towards observing and studying CP violation and B s flavor oscillations. Estimates of expected performance are reported. The new detector systems described are: the 5-layer 3-D silicon vertex detector, the intermedia silicon tracking layers, the central tracking drift chamber, muon system upgrades, and a proposed time-of-flight system.

Measurements of 55Fe activity in activated steel samples with GEMPix

NASA Astrophysics Data System (ADS)

Curioni, A.; Dinar, N.; La Torre, F. P.; Leidner, J.; Murtas, F.; Puddu, S.; Silari, M.

2017-03-01

In this paper we present a novel method, based on the recently developed GEMPix detector, to measure the 55Fe content in samples of metallic material activated during operation of CERN accelerators and experimental facilities. The GEMPix, a gas detector with highly pixelated read-out, has been obtained by coupling a triple Gas Electron Multiplier (GEM) to a quad Timepix ASIC. Sample preparation, measurements performed on 45 samples and data analysis are described. The calibration factor (counts per second per unit specific activity) has been obtained via measurements of the 55Fe activity determined by radiochemical analysis of the same samples. Detection limit and sensitivity to the current Swiss exemption limit are calculated. Comparison with radiochemical analysis shows inconsistency for the sensitivity for only two samples, most likely due to underestimated uncertainties of the GEMPix analysis. An operative test phase of this technique is already planned at CERN.

3D reconstruction of nuclear reactions using GEM TPC with planar readout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bihałowicz, Jan Stefan

2015-02-24

The research program of the Extreme Light Infrastructure – Nuclear Physics (ELI-NP) laboratory under construction in Magurele, Romania facilities the need of developing a gaseous active-target detector providing 3D reconstruction of charged products of nuclear reactions induced by gamma beam. The monoenergetic, high-energy (E{sub γ} > 19 MeV) gamma beam of intensity 10{sup 13}γ/s allows studying nuclear reactions in astrophysics. A Time Projection Chamber with crossed strip readout (eTPC) is proposed as one of the imaging detectors. The special feature of the readout electrode structure is a 2D reconstruction based on the information read out simultaneously from three arrays ofmore » strips that form virtual pixels. It is expected to reach similar spatial resolution as for pixel readout at largely reduced cost of electronics. The paper presents the current progress and first results of the small scale prototype TPC which is a one of implementation steps towards eTPC detector proposed in the Technical Design Report of Charged Particles Detection at ELI-NP.« less

BONUS Gas Handling System

NASA Astrophysics Data System (ADS)

Ferrer, James

2004-10-01

The BONUS experiment, at the Thomas Jefferson National Accelerator Facility aims to measure structure functions of the neutron via electron scattering. In order to overcome the unavailability of a neutron target, the BONUS collaboration will use a deuterium target. By detecting the recoil (spectator) proton in coincidence with the scattered electron, the kinematics of the electron-neutron interaction will be fully determined, thus overcoming theoretical complications that arise when extracting neutron cross sections. In order to detect low energy recoil protons, in the 70-100 MeV/c range, a (6 cm-radius) radial time projection chamber (RTPC) will be used. The BONUS RTPC is based on the gas electron multiplier (GEM) technology recently developed at CERN. One of the key components of this detector is the gas handling system, designed and built to deliver the correct mixture of gas to the detector safely, accurately, and reliably. The building and testing of this system is the major contribution of James Madison University to the BONUS collaboration. This poster provides a general overview of the BONUS detector, focusing on the gas handling system.

Proton induced target fragmentation studies on solid state nuclear track detectors using Carbon radiators

NASA Astrophysics Data System (ADS)

Szabó, J.; Pálfalvi, J. K.; Strádi, A.; Bilski, P.; Swakoń, J.; Stolarczyk, L.

2018-04-01

One of the limiting factors of an astronaut's career is the dose received from space radiation. High energy protons, being the main components of the complex radiation field present on a spacecraft, give a significant contribution to the dose. To investigate the behavior of solid state nuclear track detectors (SSNTDs) if they are irradiated by such particles, SSNTD stacks containing carbon blocks were exposed to high energy proton beams (70, 100, 150 and 230 MeV) at the Proteus cyclotron, IFJ PAN -Krakow. The incident protons cannot be detected directly; however, tracks of secondary particles, recoils and fragments of the constituent atoms of the detector material and of the carbon radiator are formed. It was found that as the proton energy increases, the number of tracks induced in the PADC material by secondary particles decreases. From the measured geometrical parameters of the tracks the linear energy transfer (LET) spectrum and the dosimetric quantities were determined, applying appropriate calibration. In the LET spectra the LET range of the most important secondary particles could be identified and their abundance showed differences in the spectra if the detectors were short or long etched. The LET spectra obtained on the SSNTDs irradiated by protons were compared to LET spectra of detectors flown on the International Space Station (ISS): they were quite similar, resulting in a quality factor difference of only 5%. Thermoluminescent detectors (TLDs) were applied in each case to measure the dose from primary protons and other lower LET particles present in space. Comparing and analyzing the results of the TLD and SSNTD measurements, it was obtained that proton induced target fragments contributed to the total absorbed dose in 3.2% and to the dose equivalent in 14.2% in this particular space experiment.

A simple apparatus for quick qualitative analysis of CR39 nuclear track detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gautier, D. C.; Kline, J. L.; Flippo, K. A.

2008-10-15

Quantifying the ion pits in Columbia Resin 39 (CR39) nuclear track detector from Thomson parabolas is a time consuming and tedious process using conventional microscope based techniques. A simple inventive apparatus for fast screening and qualitative analysis of CR39 detectors has been developed, enabling efficient selection of data for a more detailed analysis. The system consists simply of a green He-Ne laser and a high-resolution digital single-lens reflex camera. The laser illuminates the edge of the CR39 at grazing incidence and couples into the plastic, acting as a light pipe. Subsequently, the laser illuminates all ion tracks on the surface.more » A high-resolution digital camera is used to photograph the scattered light from the ion tracks, enabling one to quickly determine charge states and energies measured by the Thomson parabola.« less

VIPRAM_L1CMS: a 2-Tier 3D Architecture for Pattern Recognition for Track Finding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoff, J. R.; Joshi, Joshi,S.; Liu, Liu,

In HEP tracking trigger applications, flagging an individual detector hit is not important. Rather, the path of a charged particle through many detector layers is what must be found. Moreover, given the increased luminosity projected for future LHC experiments, this type of track finding will be required within the Level 1 Trigger system. This means that future LHC experiments require not just a chip capable of high-speed track finding but also one with a high-speed readout architecture. VIPRAM_L1CMS is 2-Tier Vertically Integrated chip designed to fulfill these requirements. It is a complete pipelined Pattern Recognition Associative Memory (PRAM) architecture includingmore » pattern recognition, result sparsification, and readout for Level 1 trigger applications in CMS with 15-bit wide detector addresses and eight detector layers included in the track finding. Pattern recognition is based on classic Content Addressable Memories with a Current Race Scheme to reduce timing complexity and a 4-bit Selective Precharge to minimize power consumption. VIPRAM_L1CMS uses a pipelined set of priority-encoded binary readout structures to sparsify and readout active road flags at frequencies of at least 100MHz. VIPRAM_L1CMS is designed to work directly with the Pulsar2b Architecture.« less

A fast method for optical simulation of flood maps of light-sharing detector modules

PubMed Central

Shi, Han; Du, Dong; Xu, JianFeng; Moses, William W.; Peng, Qiyu

2016-01-01

Optical simulation of the detector module level is highly desired for Position Emission Tomography (PET) system design. Commonly used simulation toolkits such as GATE are not efficient in the optical simulation of detector modules with complicated light-sharing configurations, where a vast amount of photons need to be tracked. We present a fast approach based on a simplified specular reflectance model and a structured light-tracking algorithm to speed up the photon tracking in detector modules constructed with polished finish and specular reflector materials. We simulated conventional block detector designs with different slotted light guide patterns using the new approach and compared the outcomes with those from GATE simulations. While the two approaches generated comparable flood maps, the new approach was more than 200–600 times faster. The new approach has also been validated by constructing a prototype detector and comparing the simulated flood map with the experimental flood map. The experimental flood map has nearly uniformly distributed spots similar to those in the simulated flood map. In conclusion, the new approach provides a fast and reliable simulation tool for assisting in the development of light-sharing-based detector modules with a polished surface finish and using specular reflector materials. PMID:27660376

A fast method for optical simulation of flood maps of light-sharing detector modules

DOE PAGES

Shi, Han; Du, Dong; Xu, JianFeng; ...

2015-09-03

Optical simulation of the detector module level is highly desired for Position Emission Tomography (PET) system design. Commonly used simulation toolkits such as GATE are not efficient in the optical simulation of detector modules with complicated light-sharing configurations, where a vast amount of photons need to be tracked. Here, we present a fast approach based on a simplified specular reflectance model and a structured light-tracking algorithm to speed up the photon tracking in detector modules constructed with polished finish and specular reflector materials. We also simulated conventional block detector designs with different slotted light guide patterns using the new approachmore » and compared the outcomes with those from GATE simulations. And while the two approaches generated comparable flood maps, the new approach was more than 200–600 times faster. The new approach has also been validated by constructing a prototype detector and comparing the simulated flood map with the experimental flood map. The experimental flood map has nearly uniformly distributed spots similar to those in the simulated flood map. In conclusion, the new approach provides a fast and reliable simulation tool for assisting in the development of light-sharing-based detector modules with a polished surface finish and using specular reflector materials.« less

[Construction of Lactobacillus rhamnosus GG particles surface display system].

PubMed

Su, Runyu; Nie, Boyao; Yuan, Shengling; Tao, Haoxia; Liu, Chunjie; Yang, Bailiang; Wang, Yanchun

2017-01-25

To describe a novel particles surface display system which is consisted of gram-positive enhancer matrix (GEM) particles and anchor proteins for bacteria-like particles vaccines, we treated Lactobacillus rhamnosus GG bacteria with 10% heated-TCA for preparing GEM particles, and then identified the harvested GEM particles by electron microscopy, RT-PCR and SDS-PAGE. Meanwhile, Escherichia coli was induced to express hybrid proteins PA3-EGFP and P60-EGFP, and GEM particles were incubated with them. Then binding of anchor proteins were determined by Western blotting, transmission electron microscopy, fluorescence microscopy and spectrofluorometry. GEM particles preserved original size and shape, and proteins and DNA contents of GEM particles were released substantially. The two anchor proteins both had efficiently immobilized on the surface of GEM. GEM particles that were bounded by anchor proteins were brushy. The fluorescence of GEM particles anchoring PA3 was slightly brighter than P60, but the difference was not significant (P>0.05). GEM particles prepared from L. rhamnosus GG have a good binding efficiency with anchor proteins PA3-EGFP and P60-EGFP. Therefore, this novel foreign protein surface display system could be used for bacteria-like particle vaccines.

Research on anisotropy of fusion-produced protons and neutrons emission from high-current plasma-focus discharges.

PubMed

Malinowski, K; Skladnik-Sadowska, E; Sadowski, M J; Szydlowski, A; Czaus, K; Kwiatkowski, R; Zaloga, D; Paduch, M; Zielinska, E

2015-01-01

The paper concerns fast protons and neutrons from D-D fusion reactions in a Plasma-Focus-1000U facility. Measurements were performed with nuclear-track detectors arranged in "sandwiches" of an Al-foil and two PM-355 detectors separated by a polyethylene-plate. The Al-foil eliminated all primary deuterons, but was penetrable for fast fusion protons. The foil and first PM-355 detector were penetrable for fast neutrons, which were converted into recoil-protons in the polyethylene and recorded in the second PM-355 detector. The "sandwiches" were irradiated by discharges of comparable neutron-yields. Analyses of etched tracks and computer simulations of the fusion-products behavior in the detectors were performed.

Research on anisotropy of fusion-produced protons and neutrons emission from high-current plasma-focus discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malinowski, K., E-mail: karol.malinowski@ncbj.gov.pl; Sadowski, M. J.; Szydlowski, A.

2015-01-15

The paper concerns fast protons and neutrons from D-D fusion reactions in a Plasma-Focus-1000U facility. Measurements were performed with nuclear-track detectors arranged in “sandwiches” of an Al-foil and two PM-355 detectors separated by a polyethylene-plate. The Al-foil eliminated all primary deuterons, but was penetrable for fast fusion protons. The foil and first PM-355 detector were penetrable for fast neutrons, which were converted into recoil-protons in the polyethylene and recorded in the second PM-355 detector. The “sandwiches” were irradiated by discharges of comparable neutron-yields. Analyses of etched tracks and computer simulations of the fusion-products behavior in the detectors were performed.

The histone methyltransferase G9a as a therapeutic target to override gemcitabine resistance in pancreatic cancer

PubMed Central

Pan, Mei-Ren; Hsu, Ming-Chuan; Luo, Chi-Wen; Chen, Li-Tzong; Shan, Yan-Shen; Hung, Wen-Chun

2016-01-01

Gemcitabine (GEM) resistance is a critical issue for pancreatic cancer treatment. The involvement of epigenetic modification in GEM resistance is still unclear. We established a GEM-resistant subline PANC-1-R from the parental PANC-1 pancreatic cancer cells and found the elevation of various chromatin-modifying enzymes including G9a in GEM-resistant cells. Ectopic expression of G9a in PANC-1 cells increased GEM resistance while inactivation of G9a in PANC-1-R cells reduced it. Challenge of PANC-1 cells with GEM increased the expression of stemness markers including CD133, nestin and Lgr5 and promoted sphere forming activity suggesting chemotherapy enriched cancer cells with stem-like properties. Inhibition of G9a in PANC-1-R cells reduced stemness and invasiveness and sensitized the cells to GEM. We revealed interleukin-8 (IL-8) is a downstream effector of G9a to increase GEM resistance. G9a-overexpressing PANC-1-R cells exhibited autocrine IL-8/CXCR1/2 stimulation to increase GEM resistance which could be decreased by anti-IL-8 antibody and G9a inhibitor. IL-8 released by cancer cells also activated pancreatic stellate cell (PSC) to increase GEM resistance. In orthotopic animal model, GEM could not suppress tumor growth of PANC-1-R cells and eventually promoted tumor metastasis. Combination with G9a inhibitor and GEM reduced tumor growth, metastasis, IL-8 expression and PSC activation in animals. Finally, we showed that overexpression of G9a correlated with poor survival and early recurrence in pancreatic cancer patients. Collectively, our results suggest G9a is a therapeutic target to override GEM resistance in the treatment of pancreatic cancer. PMID:27531902

On gravity from SST, geoid from SEASAT, and plate age and fracture zones in the Pacific

NASA Technical Reports Server (NTRS)

Marsh, B. D.; Marsh, J. G.; Williamson, R. G.

1983-01-01

Data from an additional 50 satellite-to-satellite tracking (SST) passes were combined with earlier measurements of the high degree and order (n, m, 12) gravity in the central Pacific. A composite map was produced which shows good agreement with conventional GEM models. Data from the SEASAT altimeter was reduced and found to agree well with both the SST and the GEM fields. The maps are dominated especially in the east, by a pattern of roughly east-west anomalies with a transverse wavelength of about 2000 km. Further comparison with regional bathymetric data shows a remarkably close correlation with plate age. Each anomaly band is framed by those major fracture zones having large offsets. The regular spacing of these fractures seems to account for the fabric in the gravity fields. Other anomalies are accounted for by hot spots. The source of part of these anomalies is in the lithosphere itself. The possible plume size and ascent velocity necessary to supply deep mantle material to the upper mantel without complete thermal equilibration is considered.

Optimization of the microcable and detector parameters towards low noise in the STS readout system

NASA Astrophysics Data System (ADS)

Kasinski, Krzysztof; Kleczek, Rafal; Schmidt, Christian J.

2015-09-01

Successful operation of the Silicon Tracking System requires charge measurement of each hit with equivalent noise charge lower than 1000 e- rms. Detector channels will not be identical, they will be constructed accordingly to the estimated occupancy, therefore for the readout electronics, detector system will exhibit various parameters. This paper presents the simulation-based study on the required microcable (trace width, dielectric material), detector (aluminum strip resistance) and external passives' (decoupling capacitors) parameters in the Silicon Tracking System. Studies will be performed using a front-end electronics (charge sensitive amplifier with shaper) designed for the power budget of 10 mA/channel.

Autoradiography imaging in targeted alpha therapy with Timepix detector.

PubMed

A L Darwish, Ruqaya; Staudacher, Alexander Hugo; Bezak, Eva; Brown, Michael Paul

2015-01-01

There is a lack of data related to activity uptake and particle track distribution in targeted alpha therapy. These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells. Tracking of individual alpha particles is possible using the Timepix semiconductor radiation detector. We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. Additionally, the sensitivity of the Timepix detector to monitor variations in tumour uptake based on the necrotic tissue volume was also studied. Compartmental analysis model was used, based on the obtained imaging data, to assess the Th-227 uptake. Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector. The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector. Furthermore, the variations in the uptake based on the tumour necrotic volume have been observed with four times higher uptake for tumours pretreated with chemotherapy than for those without chemotherapy.

Autoradiography Imaging in Targeted Alpha Therapy with Timepix Detector

PubMed Central

AL Darwish, Ruqaya; Staudacher, Alexander Hugo; Bezak, Eva; Brown, Michael Paul

2015-01-01

There is a lack of data related to activity uptake and particle track distribution in targeted alpha therapy. These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells. Tracking of individual alpha particles is possible using the Timepix semiconductor radiation detector. We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. Additionally, the sensitivity of the Timepix detector to monitor variations in tumour uptake based on the necrotic tissue volume was also studied. Compartmental analysis model was used, based on the obtained imaging data, to assess the Th-227 uptake. Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector. The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector. Furthermore, the variations in the uptake based on the tumour necrotic volume have been observed with four times higher uptake for tumours pretreated with chemotherapy than for those without chemotherapy. PMID:25688285

Electronics for CMS Endcap Muon Level-1 Trigger System Phase-1 and HL LHC upgrades

NASA Astrophysics Data System (ADS)

Madorsky, A.

2017-07-01

To accommodate high-luminosity LHC operation at a 13 TeV collision energy, the CMS Endcap Muon Level-1 Trigger system had to be significantly modified. To provide robust track reconstruction, the trigger system must now import all available trigger primitives generated by the Cathode Strip Chambers and by certain other subsystems, such as Resistive Plate Chambers (RPC). In addition to massive input bandwidth, this also required significant increase in logic and memory resources. To satisfy these requirements, a new Sector Processor unit has been designed. It consists of three modules. The Core Logic module houses the large FPGA that contains the track-finding logic and multi-gigabit serial links for data exchange. The Optical module contains optical receivers and transmitters; it communicates with the Core Logic module via a custom backplane section. The Pt Lookup table (PTLUT) module contains 1 GB of low-latency memory that is used to assign the final Pt to reconstructed muon tracks. The μ TCA architecture (adopted by CMS) was used for this design. The talk presents the details of the hardware and firmware design of the production system based on Xilinx Virtex-7 FPGA family. The next round of LHC and CMS upgrades starts in 2019, followed by a major High-Luminosity (HL) LHC upgrade starting in 2024. In the course of these upgrades, new Gas Electron Multiplier (GEM) detectors and more RPC chambers will be added to the Endcap Muon system. In order to keep up with all these changes, a new Advanced Processor unit is being designed. This device will be based on Xilinx UltraScale+ FPGAs. It will be able to accommodate up to 100 serial links with bit rates of up to 25 Gb/s, and provide up to 2.5 times more logic resources than the device used currently. The amount of PTLUT memory will be significantly increased to provide more flexibility for the Pt assignment algorithm. The talk presents preliminary details of the hardware design program.

GEM at 10: a decade's experience with the Guideline Elements Model.

PubMed

Hajizadeh, Negin; Kashyap, Nitu; Michel, George; Shiffman, Richard N

2011-01-01

The Guideline Elements Model (GEM) was developed in 2000 to organize the information contained in clinical practice guidelines using XML and to represent guideline content in a form that can be understood by human readers and processed by computers. In this work, we systematically reviewed the literature to better understand how GEM was being used, potential barriers to its use, and suggestions for improvement. Fifty external and twelve internally produced publications were identified and analyzed. GEM was used most commonly for modeling and ontology creation. Other investigators applied GEM for knowledge extraction and data mining, for clinical decision support for guideline generation. The GEM Cutter software-used to markup guidelines for translation into XML- has been downloaded 563 times since 2000. Although many investigators found GEM to be valuable, others critiqued its failure to clarify guideline semantics, difficulties in markup, and the fact that GEM files are not usually executable.

Gravity model improvement using GEOS-3 (GEM 9 and 10)

NASA Technical Reports Server (NTRS)

Lerch, F. J.; Klosko, S. M.; Laubscher, R. E.; Wagner, C. A.

1977-01-01

The use of collocation permitted GEM 9 to be a larger field than previous derived satellite models, GEM 9 having harmonics complete to 20 x 20 with selected higher degree terms. The satellite data set has approximately 840,000 observations, of which 200,000 are laser ranges taken on 9 satellites equipped with retroreflectors. GEM 10 is complete to 22 x 22 with selected higher degree terms out to degree and order 30 amounting to a total of 592 coefficients. Comparisons with surface gravity and altimeter data indicate a substantial improvement in GEM 9 over previous satellite solutions; GEM 9 is in even closer agreement with surface data than the previously published GEM 6 solution which contained surface gravity. In particular the free air gravity anomalies calculated from GEM 9 and a surface gravity solution are in excellent agreement for the high degree terms.

Analysis Strategy and Selection Procedure for νμ Charged Current Inclusive Interactions using the ^0 Detector (P0D) and the Time Projection Chambers of the T2K Experiment

NASA Astrophysics Data System (ADS)

Reinherz-Aronis, Erez; Clifton, Alex; Das, Raj; Toki, Walter; Johnson, Robert; Marino, Alysia; Yuan, Tianlu

2013-04-01

νμ Charge-Current events are produced and collected by the Near Detectors (ND280) in the Tokai to Kamioka (T2K) experiment. This talk focuses on those interactions that are created in the Pi-Zero detector (PøD) and whose momentum is measured by the Time Projection Chambers (TPC). The description of the analysis event selection is presented which includes Data-Quality cuts, Beam Quality parameters, and Fiducial Volume boundaries which are applied on the beginning of the PøD track. In addition the matching procedure of a TPC track to a PøD track and the optimization of this procedure in presented.

Data-Fusion for a Vision-Aided Radiological Detection System: Sensor dependence and Source Tracking

NASA Astrophysics Data System (ADS)

Stadnikia, Kelsey; Martin, Allan; Henderson, Kristofer; Koppal, Sanjeev; Enqvist, Andreas

2018-01-01

The University of Florida is taking a multidisciplinary approach to fuse the data between 3D vision sensors and radiological sensors in hopes of creating a system capable of not only detecting the presence of a radiological threat, but also tracking it. The key to developing such a vision-aided radiological detection system, lies in the count rate being inversely dependent on the square of the distance. Presented in this paper are the results of the calibration algorithm used to predict the location of the radiological detectors based on 3D distance from the source to the detector (vision data) and the detectors count rate (radiological data). Also presented are the results of two correlation methods used to explore source tracking.

A global station coordinate solution based upon camera and laser data - GSFC 1973

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Douglas, B. C.; Klosko, S. M.

1973-01-01

Results for the geocentric coordinates of 72 globally distributed satellite tracking stations consisting of 58 cameras and 14 lasers are presented. The observational data for this solution consists of over 65,000 optical observations and more than 350 laser passes recorded during the National Geodetic Satellite Program, the 1968 Centre National d'Etudes Spatiales/Smithsonian Astrophysical Observatory (SAO) Program, and International Satellite Geodesy Experiment Program. Dynamic methods were used. The data were analyzed with the GSFC GEM and SAO 1969 Standard Earth Gravity Models. The recent value of GM = 398600.8 cu km/sec square derived at the Jet Propulsion Laboratory (JPL) gave the best results for this combination laser/optical solution. Solutions are made with the deep space solution of JPL (LS-25 solution) including results obtained at GSFC from Mariner-9 Unified B-Band tracking. Datum transformation parameters relating North America, Europe, South America, and Australia are given, enabling the positions of some 200 other tracking stations to be placed in the geocentric system.

A method for (n,alpha) and (n,p) cross section measurements using a lead slowing-down spectrometer

NASA Astrophysics Data System (ADS)

Thompson, Jason Tyler

The need for nuclear data comes from several sources including astrophysics, stockpile stewardship, and reactor design. Photodisintegration, neutron capture, and charged particle out reactions on stable or short-lived radioisotopes play crucial roles during stellar evolution and forming solar isotopic abundances whereas these reactions can affect the safety of our national weapons stockpile or criticality and safety calculations for reactors. Although models can be used to predict some of these values, these predictions are only as good as the experimental data that constrains them. For neutron-induced emission of α particles and protons ((n,α) and (n,p) reactions) at energies below 1 MeV, the experimental data is at best scarce and models must rely on extrapolations from unlike situations, (i.e. different reactions, isotopes, and energies) providing ample room for uncertainty. In this work a new method of measuring energy dependent (n,α) and (n,p) cross sections was developed for the energy range of 0.1 eV - ˜100 keV using a lead slowing-down spectrometer (LSDS). The LSDS provides a ˜10 4 neutron flux increase over the more conventionally used time-of-flight (ToF) methods at equivalent beam conditions, allowing for the measurement of small cross sections (µb’s to mb’s) while using small sample masses (µg’s to mg’s). Several detector concepts were designed and tested, including specially constructed Canberra passivated, implanted, planar silicon (PIPS) detectors; and gas-electron-multiplier (GEM) foils. All designs are compensated to minimize γ-flash problems. The GEM detector was found to function satisfactory for (n,α) measurements, but the PIPS detectors were found to be better suited for (n,p) reaction measurements. A digital data acquisition (DAQ) system was programmed such that background can be measured simultaneously with the reaction cross section. Measurements of the 147Sm(n,α)144Nd and 149 Sm(n,α)146Nd reaction cross sections were performed as proofs of concept. The measurement of 147Sm verified and extended a previous measurement while the measurement of 149Sm is the first over the majority of the 0.1 eV to 100 keV energy region.

Calibration of large area Micromegas detectors using cosmic rays

NASA Astrophysics Data System (ADS)

Biebel, O.; Flierl, B.; Herrmann, M.; Hertenberger, R.; Klitzner, F.; Lösel, P.; Müller, R.; Valderanis, C.; Zibell, A.

2017-06-01

Currently m2-sized micropattern detectors with spatial resolution better than 100 μm and online trigger capability are of big interest for many experiments. Large size in combination with superb spatial resolution and trigger capability implicates that the construction of these detectors is highly sophisticated and imposes strict mechanical tolerances. We developed a method to survey assembled and working detectors on potential deviations of the micro pattern readout structures from design value as well as deformations of the whole detector, using cosmic muons in a tracking facility. The LMU Cosmic Ray Facility consists of two 8 m2 ATLAS Monitored Drift Tube chambers (MDT) for precision muon reference tracking and two segmented trigger hodoscopes with sub-ns time-resolution and additional 10 cm position information along the wires of the MDTs. It provides information on homogeneity in efficiency and pulse height of one or several micropattern detectors installed in between the MDTs. With an angular acceptance of -30° to +30° the comparison of the reference muon tracking with centroidal position determination or time projection chamber like track reconstruction in the micropattern detector allows for calibration in three dimensions. We present results of a m2-sized one-dimensional resistive strip Micromegas detector consisting of two readout boards with in total 2048 strips, read out by 16 APV25 front-end boards. This 16-fold segmentation along the precision direction in combination with a 10-fold segmentation in orthogonal direction by the resolution of the trigger hodoscope, allows for very detailed analysis of the 1 m2 detector under study by subdivision into 160 partitions, each being analyzed separately. We are able to disentangle deviations from the readout strip straightness and global deformation due to the small overpressure caused by the Ar:CO2 (93:7) gas mixture flux. We introduce the alignment and calibration procedure, report on homogeneity in efficiency and pulse height and present results on deformation and performance of the m2-sized Micromegas.

Test beam performance measurements for the Phase I upgrade of the CMS pixel detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dragicevic, M.; Friedl, M.; Hrubec, J.

A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase~I Upgrade of the LHC. The new CMS pixel detector provides four-hit tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. Here in this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency ismore » $$99.95\\pm0.05\\,\\%$$, while the intrinsic spatial resolutions are $$4.80\\pm0.25\\,\\mu \\mathrm{m}$$ and $$7.99\\pm0.21\\,\\mu \\mathrm{m}$$ along the $$100\\,\\mu \\mathrm{m}$$ and $$150\\,\\mu \\mathrm{m}$$ pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.« less

Automatic neutron dosimetry system based on fluorescent nuclear track detector technology.

PubMed

Akselrod, M S; Fomenko, V V; Bartz, J A; Haslett, T L

2014-10-01

For the first time, the authors are describing an automatic fluorescent nuclear track detector (FNTD) reader for neutron dosimetry. FNTD is a luminescent integrating type of detector made of aluminium oxide crystals that does not require electronics or batteries during irradiation. Non-destructive optical readout of the detector is performed using a confocal laser scanning fluorescence imaging with near-diffraction limited resolution. The fully automatic table-top reader allows one to load up to 216 detectors on a tray, read their engraved IDs using a CCD camera and optical character recognition, scan and process simultaneously two types of images in fluorescent and reflected laser light contrast to eliminate false-positive tracks related to surface and volume crystal imperfections. The FNTD dosimetry system allows one to measure neutron doses from 0.1 mSv to 20 Sv and covers neutron energies from thermal to 20 MeV. The reader is characterised by a robust, compact optical design, fast data processing electronics and user-friendly software. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Test beam performance measurements for the Phase I upgrade of the CMS pixel detector

DOE PAGES

Dragicevic, M.; Friedl, M.; Hrubec, J.; ...

2017-05-30

A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase~I Upgrade of the LHC. The new CMS pixel detector provides four-hit tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. Here in this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency ismore » $$99.95\\pm0.05\\,\\%$$, while the intrinsic spatial resolutions are $$4.80\\pm0.25\\,\\mu \\mathrm{m}$$ and $$7.99\\pm0.21\\,\\mu \\mathrm{m}$$ along the $$100\\,\\mu \\mathrm{m}$$ and $$150\\,\\mu \\mathrm{m}$$ pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.« less

[Survivability and morphologic anomalies in higher plants wolffia arrhiza following exposure to heavy ions of the galactic space radiation].

PubMed

Nevzgodina, L V; Kaminskaia, E V; Maksimova, E N; Fatsius, R; Sherrer, K; Shtraukh, V

2000-01-01

Experimental data on the effects of spaceflight factors, space radiation in particular, on higher plant Wolffia arrhiza firstly exposed in the "Bioblock" assembly and measurements made by physical track detectors of heavy ions (HI) are presented. Death of individual Wolffia plants and morphologic anomalies were the basic evaluation criteria. The peculiar feature of this biological object consists in the possibility to reveal delayed effects after 1-2 months since space flight as Wolffia has a high rate of vegetative reproduction. German investigators through microscopic examination of track detectors performed identification of individual plants affected by HI. With specially developed software and a coordinate system of supposition of biolayers and track detectors with the accuracy of 1 micron, tracks and even separate sections of individual HI tracks were determined in biological objects. Thereafter each Wolffia plant hit by HI was examined and data were compared with other variants. As a result, correlation between Wolffia death rate and morphologic anomalies were determined at different times post flight and topography of HI tracks was found. It is hypothesized that morphological anomalies in Walffia were caused by direct hits of plant germs by heavy ions or close passage of particles.

A study of commercially-available polyethylene terephthalate (PET) and polycarbonate as nuclear track detector materials

NASA Astrophysics Data System (ADS)

Espinosa, G.; Golzarri, J. I.; Vazquez-Lopez, C.; Trejo, R.; Lopez, K.; Rickards, J.

2014-07-01

In the study of the sensitivity of materials to be used as nuclear track detectors, it was found that commercial polyethylene terephthalate (PET) from Ciel® water bottles, commercial roof cover polycarbonate, and recycled packaging strips (recycled PET), can be used as nuclear track detectors. These three commercial materials present nuclear tracks when bombarded by 2.27 MeV nitrogen ions produced in a Pelletron particle accelerator, and by fission fragments from a 252Cf source (79.4 and 103.8 MeV), after a chemical etching with a 6.25M KOH solution, or with a 6.25M KOH solution with 20% methanol, both solutions at 60±1°C. As an example, the nitrogen ions deposit approximately 1 keV/nm in the form of ionization and excitation at the surface of PET, as calculated using the SRIM code. The fission fragments deposit up to 9 keV/nm at the surface, in both cases generating sufficient free radicals to initiate the track formation process. However, 5 MeV alpha particles, typical of radon (222Rn) emissions, deposit only 0.12 keV/nm, do not present tracks after the chemical etching process. This valuable information could be very useful for further studies of new materials in nuclear track methodology.

Hyaluronic acid-coated, prodrug-based nanostructured lipid carriers for enhanced pancreatic cancer therapy.

PubMed

Lu, Zhihe; Su, Jingrong; Li, Zhengrong; Zhan, Yuzhu; Ye, Decai

2017-01-01

Gemcitabine (GEM) and Baicalein (BCL) are reported to have anti-tumor effects including pancreatic cancer. Hyaluronic acid (HA) can bind to over-expressed receptors in various kinds of cancer cells. The aim of this study is to develop prodrugs containing HA, BCL and GEM, and construct nanomedicine incorporate GEM and BCL in the core and HA on the surface. This system could target the cancer cells and co-deliver the drugs. GEM-stearic acid lipid prodrug (GEM-SA) and hyaluronic acid-amino acid-baicalein prodrug (HA-AA-BCL) were synthesized. Then, GEM and BCL prodrug-based targeted nanostructured lipid carriers (HA-GEM-BCL NLCs) were prepared by the nanoprecipitation technique. The in vitro cytotoxicity studies of the NLCs were evaluated on AsPC1 pancreatic cancer cell line. In vivo anti-tumor effects were observed on the murine-bearing pancreatic cancer model. HA-GEM-BCL NLCs were effective in entering pancreatic cancer cells over-expressing HA receptors, and showed cytotoxicity of tumor cells in vitro. In vivo study revealed significant tumor growth inhibition ability of HA-GEM-BCL NLCs in murine pancreatic cancer model. It could be concluded that HA-GEM-BCL NLCs could be featured as promising co-delivery, tumor-targeted nanomedicine for the treatment of cancers.

GEMS and New Pre-Accretionally Irradiated RELICT Grains in Interplanetary Dust - The Plot Thickens

NASA Astrophysics Data System (ADS)

Bradley, J.

1995-09-01

The hypothesis that GEMS (glass with embedded metal and sulfides) in interplanetary dust particles (IDPs) might be the long-sought interstellar silicate grains is undergoing close scrutiny [1-3]. GEMS are proposed to be interstellar because: (a) they are abundant in cometary IDPs; (b) they were irradiated prior to incorporation into IDPs; (c) both their size distribution and Oamorphous silicate" microstructures are consistent with those of interstellar silicates; (d) they contain nanometer-sized (superparamagnetic) alpha-iron inclusions, which provides a simple explanation for the observed interstellar grain alignment and polarization [4,5]. Challenges to the GEMS hypothesis include the following: (a) GEMS may have formed and been irradiated in the solar nebula rather than a presolar interstellar environment; (b) non-solar isotope abundances have yet to be measured in GEMS; (c) the irradiation regime required to produce the observed effects in GEMS might be incompatible with the interstellar medium; (b) relationships between GEMS and carbon (e.g. core/mantle) need clarification; (c) major element abundances in GEMS should be consistent with observed interstellar gas phase depletions [2,3]. GEMS may indeed have formed in the solar nebula, in which case they would be the oldest known solar nebula solids [2]. An interstellar origin for GEMS does not require detection of non-solar isotope abundances [6]. Irradiation experiments are in progress to simulate the properties of GEMS. The petrographic relationship between GEMS and carbon in IDPs is being investigated (by examining IDPs embedded and thin-sectioned in carbon-free media). Major element abundances in GEMS are being evaluated in terms on interstellar gas phase abundances. For example, sulfur is not highly depleted in the interstellar gas, implying that it must be significantly depleted in interstellar grains [3]. GEMS are significantly depleted in sulfur relative to solar abundances. Analytical electron microscopic studies of the local petrographic environment of GEMS in IDPs are continuing. There is evidence of a population of relict grains associated with GEMS. Some of these relict grains have distinctive compositions and they appear to have functioned as (pre-existing) depositional substrates while GEMS were being formed. Thus, it may be possible to begin to assign a chronology to the seemingly complex admixture of grains that make up the ultrafine-grained matrices of anhydrous chondritic IDPs. References: [1] Bradley J. P. (1994) Science, 265, 925-929. [2] Flynn G. J. (1994) Nature, 371, 287-288. [3] Martin P. G. (1995) Astrophys. J., 445, L63-L66. [4] Mathis J. S. (1986) Astrophys. J., 308, 281-287. [5] Mathis J. S. (1993) Rept. Prog. Phys., 56, 605-652. [6] Walker R. M. (1994) in Analysis of Interplanetary Dust (M. E. Zolensky et al., eds.), pp. 203-209, AIP Conf. Proc. 310.

Recent developments in track reconstruction and hadron identification at MPD

NASA Astrophysics Data System (ADS)

Mudrokh, A.; Zinchenko, A.

2017-03-01

A Monte Carlo simulation of real detector effects with as many details as possible has been carried out instead of a simplified Geant point smearing approach during the study of the detector performance. Some results of realistic simulation of the MPD TPC (Time Projection Chamber) including digitization in central Au+Au collisions have been obtained. Particle identification (PID) has been tuned to account for modifications in the track reconstruction. Some results on hadron identification in the TPC and TOF (Time Of Flight) detectors with realistically simulated response have been also obtained.

Evaluation of Detector-to-Detector and Mirror Side Differences for Terra MODIS Reflective Solar Bands Using Simultaneous MISR Observations

NASA Technical Reports Server (NTRS)

Wu, Aisheng; Xiong, Xiaoxiong; Angal, A.; Barnes, W.

2011-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) is one of the five Earth-observing instruments on-board the National Aeronautics and Space Administration (NASA) Earth-Observing System(EOS) Terra spacecraft, launched in December 1999. It has 36 spectral bands with wavelengths ranging from 0.41 to 14.4 mm and collects data at three nadir spatial resolutions: 0.25 km for 2 bands with 40 detectors each, 0.5 km for 5 bands with 20 detectors each and 1 km for the remaining 29 bands with 10 detectors each. MODIS bands are located on four separate focal plane assemblies (FPAs) according to their spectral wavelengths and aligned in the cross-track direction. Detectors of each spectral band are aligned in the along-track direction. MODIS makes observations using a two-sided paddle-wheel scan mirror. Its on-board calibrators (OBCs) for the reflective solar bands (RSBs) include a solar diffuser (SD), a solar diffuser stability monitor (SDSM) and a spectral-radiometric calibration assembly (SRCA). Calibration is performed for each band, detector, sub-sample (for sub-kilometer resolution bands) and mirror side. In this study, a ratio approach is applied to MODIS observed Earth scene reflectances to track the detector-to-detector and mirror side differences. Simultaneous observed reflectances from the Multi-angle Imaging Spectroradiometer (MISR), also onboard the Terra spacecraft, are used with MODIS observed reflectances in this ratio approach for four closely matched spectral bands. Results show that the detector-to-detector difference between two adjacent detectors within each spectral band is typically less than 0.2% and, depending on the wavelengths, the maximum difference among all detectors varies from 0.5% to 0.8%. The mirror side differences are found to be very small for all bands except for band 3 at 0.44 mm. This is the band with the shortest wavelength among the selected matching bands, showing a time-dependent increase for the mirror side difference. This study is part of the effort by the MODIS Characterization Support Team (MCST) in order to track the RSB on-orbit performance for MODIS collection 5 data products. To support MCST efforts for future data re-processing, this analysis will be extended to include more spectral bands and temporal coverage.

The HEP.TrkX Project: deep neural networks for HL-LHC online and offline tracking

DOE PAGES

Farrell, Steven; Anderson, Dustin; Calafiura, Paolo; ...

2017-08-08

Particle track reconstruction in dense environments such as the detectors of the High Luminosity Large Hadron Collider (HL-LHC) is a challenging pattern recognition problem. Traditional tracking algorithms such as the combinatorial Kalman Filter have been used with great success in LHC experiments for years. However, these state-of-the-art techniques are inherently sequential and scale poorly with the expected increases in detector occupancy in the HL-LHC conditions. The HEP.TrkX project is a pilot project with the aim to identify and develop cross-experiment solutions based on machine learning algorithms for track reconstruction. Machine learning algorithms bring a lot of potential to this problemmore » thanks to their capability to model complex non-linear data dependencies, to learn effective representations of high-dimensional data through training, and to parallelize easily on high-throughput architectures such as GPUs. This contribution will describe our initial explorations into this relatively unexplored idea space. Furthermore, we will discuss the use of recurrent (LSTM) and convolutional neural networks to find and fit tracks in toy detector data.« less

The HEP.TrkX Project: deep neural networks for HL-LHC online and offline tracking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrell, Steven; Anderson, Dustin; Calafiura, Paolo

Particle track reconstruction in dense environments such as the detectors of the High Luminosity Large Hadron Collider (HL-LHC) is a challenging pattern recognition problem. Traditional tracking algorithms such as the combinatorial Kalman Filter have been used with great success in LHC experiments for years. However, these state-of-the-art techniques are inherently sequential and scale poorly with the expected increases in detector occupancy in the HL-LHC conditions. The HEP.TrkX project is a pilot project with the aim to identify and develop cross-experiment solutions based on machine learning algorithms for track reconstruction. Machine learning algorithms bring a lot of potential to this problemmore » thanks to their capability to model complex non-linear data dependencies, to learn effective representations of high-dimensional data through training, and to parallelize easily on high-throughput architectures such as GPUs. This contribution will describe our initial explorations into this relatively unexplored idea space. Furthermore, we will discuss the use of recurrent (LSTM) and convolutional neural networks to find and fit tracks in toy detector data.« less

The HEP.TrkX Project: deep neural networks for HL-LHC online and offline tracking

NASA Astrophysics Data System (ADS)

Farrell, Steven; Anderson, Dustin; Calafiura, Paolo; Cerati, Giuseppe; Gray, Lindsey; Kowalkowski, Jim; Mudigonda, Mayur; Prabhat; Spentzouris, Panagiotis; Spiropoulou, Maria; Tsaris, Aristeidis; Vlimant, Jean-Roch; Zheng, Stephan

2017-08-01

Particle track reconstruction in dense environments such as the detectors of the High Luminosity Large Hadron Collider (HL-LHC) is a challenging pattern recognition problem. Traditional tracking algorithms such as the combinatorial Kalman Filter have been used with great success in LHC experiments for years. However, these state-of-the-art techniques are inherently sequential and scale poorly with the expected increases in detector occupancy in the HL-LHC conditions. The HEP.TrkX project is a pilot project with the aim to identify and develop cross-experiment solutions based on machine learning algorithms for track reconstruction. Machine learning algorithms bring a lot of potential to this problem thanks to their capability to model complex non-linear data dependencies, to learn effective representations of high-dimensional data through training, and to parallelize easily on high-throughput architectures such as GPUs. This contribution will describe our initial explorations into this relatively unexplored idea space. We will discuss the use of recurrent (LSTM) and convolutional neural networks to find and fit tracks in toy detector data.

CR-39 track detector calibration for H, He, and C ions from 0.1-0.5 MeV up to 5 MeV for laser-induced nuclear fusion product identification.

PubMed

Baccou, C; Yahia, V; Depierreux, S; Neuville, C; Goyon, C; Consoli, F; De Angelis, R; Ducret, J E; Boutoux, G; Rafelski, J; Labaune, C

2015-08-01

Laser-accelerated ion beams can be used in many applications and, especially, to initiate nuclear reactions out of thermal equilibrium. We have experimentally studied aneutronic fusion reactions induced by protons accelerated by the Target Normal Sheath Acceleration mechanism, colliding with a boron target. Such experiments require a rigorous method to identify the reaction products (alpha particles) collected in detectors among a few other ion species such as protons or carbon ions, for example. CR-39 track detectors are widely used because they are mostly sensitive to ions and their efficiency is near 100%. We present a complete calibration of CR-39 track detector for protons, alpha particles, and carbon ions. We give measurements of their track diameters for energy ranging from hundreds of keV to a few MeV and for etching times between 1 and 8 h. We used these results to identify alpha particles in our experiments on proton-boron fusion reactions initiated by laser-accelerated protons. We show that their number clearly increases when the boron fuel is preformed in a plasma state.

Design and performance of the SLD vertex detector: a 307 Mpixel tracking system

NASA Astrophysics Data System (ADS)

Abe, K.; Arodzero, A.; Baltay, C.; Brau, J. E.; Breidenbach, M.; Burrows, P. N.; Chou, A. S.; Crawford, G.; Damerell, C. J. S.; Dervan, P. J.; Dong, D. N.; Emmet, W.; English, R. L.; Etzion, E.; Foss, M.; Frey, R.; Haller, G.; Hasuko, K.; Hertzbach, S. S.; Hoeflich, J.; Huffer, M. E.; Jackson, D. J.; Jaros, J. A.; Kelsey, J.; Lee, I.; Lia, V.; Lintern, A. L.; Liu, M. X.; Manly, S. L.; Masuda, H.; McKemey, A. K.; Moore, T. B.; Nichols, A.; Nagamine, T.; Oishi, N.; Osborne, L. S.; Russell, J. J.; Ross, D.; Serbo, V. V.; Sinev, N. B.; Sinnott, J.; Skarpaas, K. Viii; Smy, M. B.; Snyder, J. A.; Strauss, M. G.; Dong, S.; Suekane, F.; Taylor, F. E.; Trandafir, A. I.; Usher, T.; Verdier, R.; Watts, S. J.; Weiss, E. R.; Yashima, J.; Yuta, H.; Zapalac, G.

1997-02-01

This paper describes the design, construction, and initial operation of SLD's upgraded vertex detector which comprises 96 two-dimensional charge-coupled devices (CCDs) with a total of 307 Mpixel. Each pixel functions as an independent particle detecting element, providing space point measurements of charged particle tracks with a typical precision of 4 μm in each co-ordinate. The CCDs are arranged in three concentric cylinders just outside the beam-pipe which surrounds the e +e - collision point of the SLAC Linear Collider (SLC). The detector is a powerful tool for distinguishing displaced vertex tracks, produced by decay in flight of heavy flavour hadrons or tau leptons, from tracks produced at the primary event vertex. The requirements for this detector include a very low mass structure (to minimize multiple scattering) both for mechanical support and to provide signal paths for the CCDs; operation at low temperature with a high degree of mechanical stability; and high speed CCD readout, signal processing, and data sparsification. The lessons learned in achieving these goals should be useful for the construction of large arrays of CCDs or active pixel devices in the future in a number of areas of science and technology.

Application of a single area array detector for acquistion, tracking and point-ahead in space optical communications

NASA Technical Reports Server (NTRS)

Clark, D. L.; Cosgrove, M.; Vanvranken, R.; Park, H.; Fitzmaurice, M.

1989-01-01

Functions of acquisition, tracking, and point-ahead in space optical communications are being combined into a single system utilizing an area array detector. An analysis is presented of the feasibility concept. The key parameters are: optical power less than 1 pW at 0.86 micrometer, acquisition in less than 30 seconds in an acquisition field of view (FOV) of 1 mrad, tracking with 0.5 microrad rms noise at 1000 Hz update rate, and point ahead transfer function precision of 0.25 microrad over a region of 150 microrad. Currently available array detectors were examined. The most demanding specifications are low output noise, a high detection efficiency, a large number of pixels, and frame rates over 1kHz. A proof of concept (POC) demonstration system is currently being built utilizing the Kodak HS-40 detector (a 128 x 128 photodiode array with a 64 channel CCD readout architecture which can be operated at frame rates as high as 40,000/sec). The POC system implements a windowing scheme and special purpose digital signal processing electronic for matched filter acquisition and tracking algorithms.

Superior therapeutic efficacy of nab-paclitaxel over cremophor-based paclitaxel in locally advanced and metastatic models of human pancreatic cancer.

PubMed

Rajeshkumar, N V; Yabuuchi, Shinichi; Pai, Shweta G; Tong, Zeen; Hou, Shihe; Bateman, Scott; Pierce, Daniel W; Heise, Carla; Von Hoff, Daniel D; Maitra, Anirban; Hidalgo, Manuel

2016-08-09

Albumin-bound paclitaxel (nab-paclitaxel, nab-PTX) plus gemcitabine (GEM) combination has demonstrated efficient antitumour activity and statistically significant overall survival of patients with metastatic pancreatic ductal adenocarcinoma (PDAC) compared with GEM monotherapy. This regimen is currently approved as a standard of care treatment option for patients with metastatic PDAC. It is unclear whether cremophor-based PTX combined with GEM provide a similar level of therapeutic efficacy in PDAC. We comprehensively explored the antitumour efficacy, effect on metastatic dissemination, tumour stroma and survival advantage following GEM, PTX and nab-PTX as monotherapy or in combination with GEM in a locally advanced, and a highly metastatic orthotopic model of human PDAC. Nab-PTX treatment resulted in significantly higher paclitaxel tumour plasma ratio (1.98-fold), robust stromal depletion, antitumour efficacy (3.79-fold) and survival benefit compared with PTX treatment. PTX plus GEM treatment showed no survival gain over GEM monotherapy. However, nab-PTX in combination with GEM decreased primary tumour burden, metastatic dissemination and significantly increased median survival of animals compared with either agents alone. These therapeutic effects were accompanied by depletion of dense fibrotic tumour stroma and decreased proliferation of carcinoma cells. Notably, nab-PTX monotherapy was equivalent to nab-PTX plus GEM in providing survival advantage to mice in a highly aggressive metastatic PDAC model, indicating that nab-PTX could potentially stop the progression of late-stage pancreatic cancer. Our data confirmed that therapeutic efficacy of PTX and nab-PTX vary widely, and the contention that these agents elicit similar antitumour response was not supported. The addition of PTX to GEM showed no survival advantage, concluding that a clinical combination of PTX and GEM may unlikely to provide significant survival advantage over GEM monotherapy and may not be a viable alternative to the current standard-of-care nab-PTX plus GEM regimen for the treatment of PDAC patients.

A review of advances in pixel detectors for experiments with high rate and radiation

NASA Astrophysics Data System (ADS)

Garcia-Sciveres, Maurice; Wermes, Norbert

2018-06-01

The large Hadron collider (LHC) experiments ATLAS and CMS have established hybrid pixel detectors as the instrument of choice for particle tracking and vertexing in high rate and radiation environments, as they operate close to the LHC interaction points. With the high luminosity-LHC upgrade now in sight, for which the tracking detectors will be completely replaced, new generations of pixel detectors are being devised. They have to address enormous challenges in terms of data throughput and radiation levels, ionizing and non-ionizing, that harm the sensing and readout parts of pixel detectors alike. Advances in microelectronics and microprocessing technologies now enable large scale detector designs with unprecedented performance in measurement precision (space and time), radiation hard sensors and readout chips, hybridization techniques, lightweight supports, and fully monolithic approaches to meet these challenges. This paper reviews the world-wide effort on these developments.

The ALICE Transition Radiation Detector: Construction, operation, and performance

NASA Astrophysics Data System (ADS)

Alice Collaboration

2018-02-01

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/ c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection.

An "artificial retina" processor for track reconstruction at the full LHC crossing rate

NASA Astrophysics Data System (ADS)

Abba, A.; Bedeschi, F.; Caponio, F.; Cenci, R.; Citterio, M.; Cusimano, A.; Fu, J.; Geraci, A.; Grizzuti, M.; Lusardi, N.; Marino, P.; Morello, M. J.; Neri, N.; Ninci, D.; Petruzzo, M.; Piucci, A.; Punzi, G.; Ristori, L.; Spinella, F.; Stracka, S.; Tonelli, D.; Walsh, J.

2016-07-01

We present the latest results of an R&D study for a specialized processor capable of reconstructing, in a silicon pixel detector, high-quality tracks from high-energy collision events at 40 MHz. The processor applies a highly parallel pattern-recognition algorithm inspired to quick detection of edges in mammals visual cortex. After a detailed study of a real-detector application, demonstrating that online reconstruction of offline-quality tracks is feasible at 40 MHz with sub-microsecond latency, we are implementing a prototype using common high-bandwidth FPGA devices.

An "artificial retina" processor for track reconstruction at the full LHC crossing rate

DOE PAGES

Abba, A.; F. Bedeschi; Caponio, F.; ...

2015-10-23

Here, we present the latest results of an R&D; study for a specialized processor capable of reconstructing, in a silicon pixel detector, high-quality tracks from high-energy collision events at 40 MHz. The processor applies a highly parallel pattern-recognition algorithm inspired to quick detection of edges in mammals visual cortex. After a detailed study of a real-detector application, demonstrating that online reconstruction of offline-quality tracks is feasible at 40 MHz with sub-microsecond latency, we are implementing a prototype using common high-bandwidth FPGA devices.

Incident angle dependence of proton response of CR-39 (TS-16) track detector

NASA Technical Reports Server (NTRS)

Oda, K.; Csige, I.; Yamauchi, T.; Miyake, H.; Benton, E. V.

1993-01-01

The proton response of the TS-16 type of CR-39 plastic nuclear track detector has been studied with accelerated and fast neutron induced protons in vacuum and in air. The diameters of etched tracks were measured as a function of etching time and the etch rate ratio and the etch induction layer were determined from the growth curve of the diameter using a variable etch rate ratio model. In the case of the accelerated protons in vacuum an anomalous incident angle dependence of the response is observed.

⁶Li-loaded directionally sensitive anti-neutrino detector for possible geo-neutrinographic imaging applications.

PubMed

Tanaka, H K M; Watanabe, H

2014-04-24

Despite the latent and unique benefits of imaging uranium and thorium's distribution in the earth's interior, previously proposed experimental techniques used to identify the incoming geo-neutrino's direction are not applicable to practical imaging due to the high miss-identification in a neutrino's track reconstruction. After performing experimental studies and Monte-Carlo simulations, we confirmed that a significant improvement is possible in neutrino tracking identification with a (6)Li-loaded neutrino detector. For possible imaging applications, we also explore the feasibility of producing geo-neutrinographic images of gigantic magmatic reservoirs and deep structure in the mantle. We anticipate and plan to apply these newly designed detectors to radiographic imaging of the Earth's interior, monitoring of nuclear reactors, and tracking astrophysical sources of neutrinos.

6Li-loaded directionally sensitive anti-neutrino detector for possible geo-neutrinographic imaging applications

PubMed Central

Tanaka, H. K. M.; Watanabe, H.

2014-01-01

Despite the latent and unique benefits of imaging uranium and thorium's distribution in the earth's interior, previously proposed experimental techniques used to identify the incoming geo-neutrino's direction are not applicable to practical imaging due to the high miss-identification in a neutrino's track reconstruction. After performing experimental studies and Monte-Carlo simulations, we confirmed that a significant improvement is possible in neutrino tracking identification with a 6Li-loaded neutrino detector. For possible imaging applications, we also explore the feasibility of producing geo-neutrinographic images of gigantic magmatic reservoirs and deep structure in the mantle. We anticipate and plan to apply these newly designed detectors to radiographic imaging of the Earth's interior, monitoring of nuclear reactors, and tracking astrophysical sources of neutrinos. PMID:24759616

Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

NASA Astrophysics Data System (ADS)

Rinderknecht, H. G.; Rojas-Herrera, J.; Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.; Sio, H.; Sinenian, N.; Rosenberg, M. J.; Li, C. K.; Séguin, F. H.; Petrasso, R. D.; Filkins, T.; Steidle, Jeffrey A.; Steidle, Jessica A.; Traynor, N.; Freeman, C.

2015-12-01

The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1-100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protons with energies in the range 0.5-9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.

Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rinderknecht, H. G.; Rojas-Herrera, J.; Zylstra, A. B.

The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protonsmore » with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. Furthermore, the impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.« less

Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rinderknecht, H. G., E-mail: rinderknecht1@llnl.gov; Rojas-Herrera, J.; Zylstra, A. B.

The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protonsmore » with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.« less

Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

DOE PAGES

Rinderknecht, H. G.; Rojas-Herrera, J.; Zylstra, A. B.; ...

2015-12-23

The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protonsmore » with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. Furthermore, the impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.« less

Compendium of Instrumentation Whitepapers on Frontier Physics Needs for Snowmass 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lipton, R.

2013-01-01

Contents of collection of whitepapers include: Operation of Collider Experiments at High Luminosity; Level 1 Track Triggers at HL-LHC; Tracking and Vertex Detectors for a Muon Collider; Triggers for hadron colliders at the energy frontier; ATLAS Upgrade Instrumentation; Instrumentation for the Energy Frontier; Particle Flow Calorimetry for CMS; Noble Liquid Calorimeters; Hadronic dual-readout calorimetry for high energy colliders; Another Detector for the International Linear Collider; e+e- Linear Colliders Detector Requirements and Limitations; Electromagnetic Calorimetry in Project X Experiments The Project X Physics Study; Intensity Frontier Instrumentation; Project X Physics Study Calorimetry Report; Project X Physics Study Tracking Report; The LHCbmore » Upgrade; Neutrino Detectors Working Group Summary; Advanced Water Cherenkov R&D for WATCHMAN; Liquid Argon Time Projection Chamber (LArTPC); Liquid Scintillator Instrumentation for Physics Frontiers; A readout architecture for 100,000 pixel Microwave Kinetic In- ductance Detector array; Instrumentation for New Measurements of the Cosmic Microwave Background polarization; Future Atmospheric and Water Cherenkov ?-ray Detectors; Dark Energy; Can Columnar Recombination Provide Directional Sensitivity in WIMP Search?; Instrumentation Needs for Detection of Ultra-high Energy Neu- trinos; Low Background Materials for Direct Detection of Dark Matter; Physics Motivation for WIMP Dark Matter Directional Detection; Solid Xenon R&D at Fermilab; Ultra High Energy Neutrinos; Instrumentation Frontier: Direct Detection of WIMPs; nEXO detector R&D; Large Arrays of Air Cherenkov Detectors; and Applications of Laser Interferometry in Fundamental Physics Experiments.« less

Studies on a 300 k pixel detector telescope

NASA Astrophysics Data System (ADS)

Middelkamp, Peter; Antinori, F.; Barberis, D.; Becks, K. H.; Beker, H.; Beusch, W.; Burger, P.; Campbell, M.; Cantatore, E.; Catanesi, M. G.; Chesi, E.; Darbo, G.; D'Auria, S.; Davia, C.; di Bari, D.; di Liberto, S.; Elia, D.; Gys, T.; Heijne, E. H. M.; Helstrup, H.; Jacholkowski, A.; Jæger, J. J.; Jakubek, J.; Jarron, P.; Klempt, W.; Krummenacher, F.; Knudson, K.; Kralik, I.; Kubasta, J.; Lasalle, J. C.; Leitner, R.; Lemeilleur, F.; Lenti, V.; Letheren, M.; Lopez, L.; Loukas, D.; Luptak, M.; Martinengo, P.; Meddeler, G.; Meddi, F.; Morando, M.; Munns, A.; Pellegrini, F.; Pengg, F.; Pospisil, S.; Quercigh, E.; Ridky, J.; Rossi, L.; Safarik, K.; Scharfetter, L.; Segato, G.; Simone, S.; Smith, K.; Snoeys, W.; Vrba, V.

1996-02-01

Four silicon pixel detector planes are combined to form a tracking telescope in the lead ion experiment WA97 at CERN with 290 304 sensitive elements each of 75 μm by 500 μm area. An electronic pulse processing circuit is associated with each individual sensing element and the response for ionizing particles is binary with an adjustable threshold. The noise rate for a threshold of 6000 e- has been measured to be less than 10-10. The inefficient area due to malfunctioning pixels is 2.8% of the 120 cm2. Detector overlaps within one plane have been used to determine the alignment of the components of the plane itself, without need for track reconstruction using external detectors. It is the first time that such a big surface covered with active pixels has been used in a physics experiment. Some aspects concerning inclined particle tracks and time walk have been measured separately in a beam test at the CERN SPS H6 beam.

TRIAC II. A MatLab code for track measurements from SSNT detectors

NASA Astrophysics Data System (ADS)

Patiris, D. L.; Blekas, K.; Ioannides, K. G.

2007-08-01

A computer program named TRIAC II written in MATLAB and running with a friendly GUI has been developed for recognition and parameters measurements of particles' tracks from images of Solid State Nuclear Track Detectors. The program, using image analysis tools, counts the number of tracks and depending on the current working mode classifies them according to their radii (Mode I—circular tracks) or their axis (Mode II—elliptical tracks), their mean intensity value (brightness) and their orientation. Images of the detectors' surfaces are input to the code, which generates text files as output, including the number of counted tracks with the associated track parameters. Hough transform techniques are used for the estimation of the number of tracks and their parameters, providing results even in cases of overlapping tracks. Finally, it is possible for the user to obtain informative histograms as well as output files for each image and/or group of images. Program summaryTitle of program:TRIAC II Catalogue identifier:ADZC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZC_v1_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer: Pentium III, 600 MHz Installations: MATLAB 7.0 Operating system under which the program has been tested: Windows XP Programming language used:MATLAB Memory required to execute with typical data:256 MB No. of bits in a word:32 No. of processors used:one Has the code been vectorized or parallelized?:no No. of lines in distributed program, including test data, etc.:25 964 No. of bytes in distributed program including test data, etc.: 4 354 510 Distribution format:tar.gz Additional comments: This program requires the MatLab Statistical toolbox and the Image Processing Toolbox to be installed. Nature of physical problem: Following the passage of a charged particle (protons and heavier) through a Solid State Nuclear Track Detector (SSNTD), a damage region is created, usually named latent track. After the chemical etching of the detectors in aqueous NaOH or KOH solutions, latent tracks can be sufficiently enlarged (with diameters of 1 μm or more) to become visible under an optical microscope. Using the appropriate apparatus, one can record images of the SSNTD's surface. The shapes of the particle's tracks are strongly dependent on their charge, energy and the angle of incidence. Generally, they have elliptical shapes and in the special case of vertical incidence, they are circular. The manual counting of tracks is a tedious and time-consuming task. An automatic system is needed to speed up the process and to increase the accuracy of the results. Method of solution: TRIAC II is based on a segmentation method that groups image pixels according to their intensity value (brightness) in a number of grey level groups. After the segmentation of pixels, the program recognizes and separates the track from the background, subsequently performing image morphology, where oversized objects or objects smaller than a threshold value are removed. Finally, using the appropriate Hough transform technique, the program counts the tracks, even those which overlap and classifies them according to their shape parameters and brightness. Typical running time: The analysis of an image with a PC (Intel Pentium III processor running at 600 MHz) requires 2 to 10 minutes, depending on the number of observed tracks and the digital resolution of the image. Unusual features of the program: This program has been tested with images of CR-39 detectors exposed to alpha particles. Also, in low contrast images with few or small tracks, background pixels can be recognized as track pixels. To avoid this problem the brightness of the background pixels should be sufficiently higher than that of the track pixels.

New installation for inclined EAS investigations

NASA Astrophysics Data System (ADS)

Zadeba, E. A.; Ampilogov, N. V.; Barbashina, N. S.; Bogdanov, A. G.; Borisov, A. A.; Chernov, D. V.; Dushkin, L. I.; Fakhrutdinov, R. M.; Kokoulin, R. P.; Kompaniets, K. G.; Kozhin, A. S.; Ovchinnikov, V. V.; Ovechkin, A. S.; Petrukhin, A. A.; Shutenko, V. V.; Volkov, N. S.; Vorobjev, V. S.; Yashin, I. I.

2017-06-01

The large-scale coordinate-tracking detector TREK for registration of inclined EAS is being developed in MEPhI. The detector is based on multiwire drift chambers from the neutrino experiment at the IHEP U-70 accelerator. Their key advantages are a large effective area (1.85 m2), a good coordinate and angular resolution with a small number of measuring channels. The detector will be operated as part of the experimental complex NEVOD, in particular, jointly with a Cherenkov water detector (CWD) with a volume of 2000 cubic meters and the coordinate detector DECOR. The first part of the detector named Coordinate-Tracking Unit based on the Drift Chambers (CTUDC), representing two coordinate planes of 8 drift chambers in each, has been developed and mounted on opposite sides of the CWD. It has the same principle of joint operation with the NEVOD-DECOR triggering system and the same drift chambers alignment, so the main features of the TREK detector will be examined. Results of the CTUDC development and a joint operation with NEVOD-DECOR complex are presented.

The design and performance of the ZEUS Central Tracking Detector z-by-timing system

NASA Astrophysics Data System (ADS)

Bailey, D. S.; Foster, B.; Heath, G. P.; Morgado, C. J. S.; Harnew, N.; Khatri, T.; Lancaster, M.; McArthur, I. C.; McFall, J. D.; Nash, J.; Shield, P. D.; Topp-Jorgensen, S.; Wilson, F. F.; Carter, R. C.; Jeffs, M. D.; Milborrow, R.; Morrissey, M. C.; Phillips, D. A.; Quinton, S. P. H.; Westlake, G.; White, D. J.; Lane, J. B.; Nixon, G.; Postranecky, M.

1997-02-01

The ZEUS Central Tracking Detector utilizes a time difference measurement to provide a fast determination of the z coordinate of each hit. The z-by-timing measurement is achieved by using a Time-to-Amplitude Converter which has an intrinsic timing resolution of 36 ps, has pipelined readout, and has a multihit capability of 48 ns. In order to maintain the required sub-nanosecond timing accuracy, the technique incorporates an automated self-calibration system. The readout of the z-by-timing data utilizes a fully customized timing control system which runs synchronously with the HERA beam-crossing clock, and a data acquisition system implemented on a network of Transputers. Three dimensional space-points provided by the z-by-timing system are used as input to all three levels of the ZEUS trigger and for offline track reconstruction. The average z resolution is determined to be 4.4 cm for multi-track events from positron-proton collisions in the ZEUS detector.

Spectral characterization of laser-accelerated protons with CR-39 nuclear track detector.

PubMed

Seimetz, M; Bellido, P; García, P; Mur, P; Iborra, A; Soriano, A; Hülber, T; García López, J; Jiménez-Ramos, M C; Lera, R; Ruiz-de la Cruz, A; Sánchez, I; Zaffino, R; Roso, L; Benlloch, J M

2018-02-01

CR-39 nuclear track material is frequently used for the detection of protons accelerated in laser-plasma interactions. The measurement of track densities allows for determination of particle angular distributions, and information on the kinetic energy can be obtained by the use of passive absorbers. We present a precise method of measuring spectral distributions of laser-accelerated protons in a single etching and analysis process. We make use of a one-to-one relation between proton energy and track size and present a precise calibration based on monoenergetic particle beams. While this relation is limited to proton energies below 1 MeV, we show that the range of spectral measurements can be significantly extended by simultaneous use of absorbers of suitable thicknesses. Examples from laser-plasma interactions are presented, and quantitative results on proton energies and particle numbers are compared to those obtained from a time-of-flight detector. The spectrum end points of continuous energy distributions have been determined with both detector types and coincide within 50-100 keV.

Comment on "The shape and composition of interstellar silicate grains"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, J P; Ishii, H

2007-09-27

In the paper entitled 'The shape and composition of interstellar silicate grains' (A & A, 462, 667-676 (2007)), Min et al. explore non-spherical grain shape and composition in modeling the interstellar 10 and 20 {micro}m extinction features. This progression towards more realistic models is vitally important to enabling valid comparisons between dust observations and laboratory measurements. Min et al. proceed to compare their model results with GEMS (glass with embedded metals and sulfides) from IDPs (interplanetary dust particles) and to discuss the nature and origin of GEMS. Specifically, they evaluate the hypothesis of Bradley (1994) that GEMS are interstellar (IS)more » amorphous silicates. From a comparison of the mineralogy, chemical compositions, and infrared (IR) spectral properties of GEMS with their modeling results, Min et al. conclude: 'GEMS are, in general, not unprocessed leftovers from the diffuse ISM'. This conclusion is based, however, on erroneous and incomplete GEMS data. It is important to clarify first that Bradley (1994) never proposed that GEMS are unprocessed leftovers from the diffuse ISM, nor did he suggest that individual subnanogram mass GEMS are a representative sampling of the enormous mass of silicates in the diffuse ISM. Bradley (1994) simply showed that GEMS properties are consistent with those of IS amorphous silicates. It is widely accepted that circumstellar outflows are important sources of IS silicates, and whether GEMS are processed or not, the circumstellar heritage of some has been rigorously confirmed through measurements of non-solar oxygen (O) isotope abundances (Messenger et al., 2003; Floss et al., 2006). Keller et al. (2000) assert that even GEMS without detectable O isotope anomalies are probably also extrasolar IS silicates because they are embedded in carbonaceous material with non-solar D/H isotopic composition. (Much of the silicate dust in the ISM may be isotopically homogenized (Zhukovska et al., 2007)). Recent measurements show that the elemental compositions of GEMS with non-solar isotopic compositions are 'remarkably similar' to those with solar isotopic compositions (Keller & Messenger, 2007). About 80% of all isotopically anomalous IS silicates identified to date are GEMS with detectable and variable O isotopic memories of a circumstellar ancestry (Messenger, 2007). Bradley (1999) proposed that GEMS are IS silicates from 'a presolar interstellar molecular cloud, presumably the local molecular cloud from which the solar system formed'. Although based on incorrect data (detailed below), Min et al. propose that most GEMS actually formed in the presolar molecular cloud, and they further propose that none of them are IS silicates. IS silicate sources include molecular clouds, circumstellar outflows, supernovae, and even recently discovered black hole winds (Molster & Waters; 2003; Jones, 2005; Zhukovska et al. 2007; Markwick-Kemper et al. 2007). The average IS 10 {micro}m extinction feature observed along lines of sight towards the galactic center (modeled by Min et al.) presumably provides a good average for IS silicates, but it cannot distinguish amorphous silicates originating in the presolar molecular cloud from amorphous silicates originating in other interstellar molecular clouds or indeed other sources of amorphous IS silicates. Even if most GEMS accreted in the presolar molecular cloud, then they must also be representatives of some portion of the IS amorphous silicate population. Laboratory heating experiments indicate it is highly unlikely that GEMS were modified in a protoplanetary accretion disk environment (Brownlee et al. 2005). In summary, Min et al. conclude from their modeling of the shape and composition of IS silicates that the properties of GEMS are generally inconsistent with those of IS silicates. First, it has been rigorously confirmed via ion microprobe measurements that some GEMS are indeed presolar IS silicates. Second, regardless of whether GEMS, or components of GEMS, originated in presolar circumstellar outflows or a presolar molecular cloud they are all IS silicates. Third, key GEMS data reported in Min et al. are inaccurate. Had complete isotopic, chemical, mineralogical and infrared (IR) spectral properties of GEMS been considered, Min et al. may have concluded that the properties of GEMS, although not an exact match, are generally consistent with those of amorphous silicates in the ISM.« less

In-laboratory development of an automatic track counting system for solid state nuclear track detectors

NASA Astrophysics Data System (ADS)

Uzun, Sefa Kemal; Demiröz, Işık; Ulus, İzzet

2017-01-01

In this study, an automatic track counting system was developed for solid state nuclear track detectors (SSNTD). Firstly the specifications of required hardware components were determined, and accordingly the CCD camera, microscope and stage motor table was supplied and integrated. The system was completed by developing parametric software with VB.Net language. Finally a set of test intended for radon activity concentration measurement was applied. According to the test results, the system was enabled for routine radon measurement. Whether the parameters of system are adjusted for another SSNTD application, it could be used for other fields of SSNTD like neutron dosimetry or heavy charged particle detection.

A Search for Optically Faint GEO Debris

DTIC Science & Technology

2011-09-01

M. Lederer NASA Orbital Debris Program Office, Johnson Space Center, Houston, TX Edwin S. Barker LZ Technology, Inc., Houston, TX Heather...fainter optical limits requires use of larger telescopes. Detectors on all small GEO survey instruments are usually CCDs, with peak quantum...CCDs. There are small gaps between the individual CCDs in the detector mosaic. The telescope can track at non-sidereal rates, allowing tracking

A vertex detector for SLD

NASA Astrophysics Data System (ADS)

Damerell, C. J. S.; English, R. L.; Gillman, A. R.; Lintern, A. L.; Phillips, D.; Rong, G.; Sutton, C.; Wickens, F. J.; Agnew, G.; Clarke, P.; Hedges, S.; Watts, S. J.

1989-03-01

The SLAC Linear Collider is currently being commissioned. A second-generation detector for SLC, known as SLD, is now under construction. In the centre of this 4000 ton detector there will be a vertex detector (VXD) consisting of 4 barrels of 2-dimensional CCDs, approximately 250 CCDs in total. This detector will be used as a tracking microscope, able to pinpoint the outgoing tracks with a precision of about 5 μm, and thus to distinguish between particles produced at the primary vertex and those which result from the decay of heavy-flavour quarks (charm, bottom and possibly others) or from the decay of heavy leptons. This paper describes the present state of the VXD project, with particular emphasis on the signal processing procedures which will reduce the 60 million measurements of pixel contents for each event to a manageable level (some tens of kilobytes).

Array-based infra-red detection: an enabling technology for people counting, sensing, tracking, and intelligent detection

NASA Astrophysics Data System (ADS)

Stogdale, Nick; Hollock, Steve; Johnson, Neil; Sumpter, Neil

2003-09-01

A 16x16 element un-cooled pyroelectric detector array has been developed which, when allied with advanced tracking and detection algorithms, has created a universal detector with multiple applications. Low-cost manufacturing techniques are used to fabricate a hybrid detector, intended for economic use in commercial markets. The detector has found extensive application in accurate people counting, detection, tracking, secure area protection, directional sensing and area violation; topics which are all pertinent to the provision of Homeland Security. The detection and tracking algorithms have, when allied with interpolation techniques, allowed a performance much higher than might be expected from a 16x16 array. This paper reviews the technology, with particular attention to the array structure, algorithms and interpolation techniques and outlines its application in a number of challenging market areas. Viewed from above, moving people are seen as 'hot blobs' moving through the field of view of the detector; background clutter or stationary objects are not seen and the detector works irrespective of lighting or environmental conditions. Advanced algorithms detect the people and extract size, shape, direction and velocity vectors allowing the number of people to be detected and their trajectories of motion to be tracked. Provision of virtual lines in the scene allows bi-directional counting of people flowing in and out of an entrance or area. Definition of a virtual closed area in the scene allows counting of the presence of stationary people within a defined area. Definition of 'counting lines' allows the counting of people, the ability to augment access control devices by confirming a 'one swipe one entry' judgement and analysis of the flow and destination of moving people. For example, passing the 'wrong way' up a denied passageway can be detected. Counting stationary people within a 'defined area' allows the behaviour and size of groups of stationary people to be analysed and counted, an alarm condition can also be generated when people stray into such areas.

High throughput on-chip analysis of high-energy charged particle tracks using lensfree imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Wei; Shabbir, Faizan; Gong, Chao

2015-04-13

We demonstrate a high-throughput charged particle analysis platform, which is based on lensfree on-chip microscopy for rapid ion track analysis using allyl diglycol carbonate, i.e., CR-39 plastic polymer as the sensing medium. By adopting a wide-area opto-electronic image sensor together with a source-shifting based pixel super-resolution technique, a large CR-39 sample volume (i.e., 4 cm × 4 cm × 0.1 cm) can be imaged in less than 1 min using a compact lensfree on-chip microscope, which detects partially coherent in-line holograms of the ion tracks recorded within the CR-39 detector. After the image capture, using highly parallelized reconstruction and ion track analysis algorithms running on graphics processingmore » units, we reconstruct and analyze the entire volume of a CR-39 detector within ∼1.5 min. This significant reduction in the entire imaging and ion track analysis time not only increases our throughput but also allows us to perform time-resolved analysis of the etching process to monitor and optimize the growth of ion tracks during etching. This computational lensfree imaging platform can provide a much higher throughput and more cost-effective alternative to traditional lens-based scanning optical microscopes for ion track analysis using CR-39 and other passive high energy particle detectors.« less

Gemcitabine-loaded albumin nanospheres (GEM-ANPs) inhibit PANC-1 cells in vitro and in vivo

NASA Astrophysics Data System (ADS)

Li, Ji; Di, Yang; Jin, Chen; Fu, Deliang; Yang, Feng; Jiang, Yongjian; Yao, Lie; Hao, Sijie; Wang, Xiaoyi; Subedi, Sabin; Ni, Quanxing

2013-04-01

With the development of nanotechnology, special attention has been given to the nanomaterial application in tumor treatment. Here, a modified desolvation-cross-linking method was successfully applied to fabricate gemcitabine-loaded albumin nanospheres (GEM-ANPs), with 110 and 406 nm of mean diameter, respectively. The aim of this study was to assess the drug distribution, side effects, and antitumor activity of GEM-ANPs in vivo. The metabolic viability and flow cytometry analysis revealed that both GEM-ANPs, especially 406-nm GEM-ANPs, could effectively inhibit the metabolism and proliferation and promote the apoptosis of human pancreatic carcinoma (PANC-1) in vitro. Intravenous injection of 406-nm GEM-ANPs exhibited a significant increase of gemcitabine in the pancreas, liver, and spleen of Sprague-Dawley rats ( p < 0.05). Moreover, no signs of toxic side effects analyzed by blood parameter changes were observed after 3 weeks of administration although a high dose (200 mg/kg) of GEM-ANPs were used. Additionally, in PANC-1-induced tumor mice, intravenous injection of 406-nm GEM-ANPs also could effectively reduce the tumor volume by comparison with free gemcitabine. With these findings, albumin nanosphere-loading approach might be efficacious to improve the antitumor activity of gemcitabine, and the efficacy is associated with the size of GEM-ANPs.

Heavy Nucleus Collector (HNC) project for the NASA Long Duration Exposure Facility (LDEF)

NASA Technical Reports Server (NTRS)

Tarle, Gregory

1990-01-01

The primary goal of the heavy nucleus collector (HNC) experiment was to obtain high resolution composition measurements for cosmic ray nuclei in the platinum-lead and actinide region of the periodic table. Secondary objectives include studies of selected groups of elements of lower charge. These goals were to be realized by orbiting a large area array of dielectric nuclear track detectors in space for several years. In this time sufficient actinide nuclei would be collected to determine the nucleosynthetic age of the cosmic radiation and the relative mix of r- and s-process elements in the cosmic ray source. The detector consists of approximately 50 trays assembled in pressurized canisters. Each tray would contain 8 half-stacks (4 stacks total) and an event thermometer which would record the temperature of each event at the time of exposure. Each stack would contain 7 layers of Rodyne-P, CR-39 and Cronar plastic track detectors interleaved with copper stripping foils. Upon return to Earth, detectors would be removed for analysis. Ultraheavy nuclei would have left tracks through the detector sheets that would be made visible after etching in a hot sodium hydroxide solution.

Facilitation of endoglin-targeting cancer therapy by development/utilization of a novel genetically engineered mouse model expressing humanized endoglin (CD105).

PubMed

Toi, Hirofumi; Tsujie, Masanori; Haruta, Yuro; Fujita, Kanako; Duzen, Jill; Seon, Ben K

2015-01-15

Endoglin (ENG) is a TGF-β coreceptor and essential for vascular development and angiogenesis. A chimeric antihuman ENG (hENG) monoclonal antibody (mAb) c-SN6j (also known as TRC105) shows promising safety and clinical efficacy features in multiple clinical trials of patients with various advanced solid tumors. Here we developed a novel genetically engineered mouse model to optimize the ENG-targeting clinical trials. We designed a new targeting vector that contains exons 4-8 of hENG gene to generate novel genetically engineered mice (GEMs) expressing functional human/mouse chimeric (humanized) ENG with desired epitopes. Genotyping of the generated mice confirmed that we generated the desired GEMs. Immunohistochemical analysis demonstrated that humanized ENG protein of the GEMs expresses epitopes defined by 7 of our 8 anti-hENG mAbs tested. Surprisingly the homozygous GEMs develop normally and are healthy. Established breast and colon tumors as well as metastasis and tumor microvessels in the GEMs were effectively suppressed by systemic administration of anti-hENG mAbs. Additionally, test result indicates that synergistic potentiation of antitumor efficacy can be induced by simultaneous targeting of two distinct epitopes by anti-hENG mAbs. Sorafenib and capecitabine also showed antitumor efficacy in the GEMs. The presented novel GEMs are the first GEMs that express the targetable humanized ENG. Test results indicate utility of the GEMs for the clinically relevant studies. Additionally, we generated GEMs expressing a different humanized ENG containing exons 5-6 of hENG gene, and the homozygous GEMs develop normally and are healthy. © 2014 UICC.

The influence of gemfibrozil on malondialdehyde level and paraoxonase 1 activity in wistar and fisher rats.

PubMed

Macan, Marija; Marija, Macan; Konjevoda, Paško; Paško, Konjevoda; Lovric, Jasna; Jasna, Lovrić; Koprivanac, Marijan; Marijan, Koprivanac; Kelava, Marta; Marta, Kelava; Vrkic, Nada; Nada, Vrkić; Bradamante, Vlasta; Vlasta, Bradamante

2011-06-01

There are diverse experimental data about the influence of gemfibrozil (GEM) on the production of hydrogen peroxide (H(2)O(2)) and antioxidant enzymes. We investigated the influence of GEM treatment on the production of malondialdehyde (MDA) level in tissues of normolipidaemic Wistar and Fisher rats which is an index of lipid peroxidation. Because serum paraoxonase 1 (PON1) is an important enzyme with specific protective function on metabolism of lipid peroxides, we examined the influence of GEM on PON1 activity in liver and serum. MDA level and enzyme activities were also determined 10 days after withdrawal of GEM treatment. The significantly increased levels of MDA in liver, kidney and heart of both rat strains were obtained after 3 weeks of GEM treatment. We propose two possibilities for the increase of MDA levels caused by GEM, induction of peroxisome proliferation and activities of enzymes that participated in occurrence of H(2)O(2) and possible reduction of enzyme activities including in H(2)O(2) metabolism. Ten days after withdrawal of GEM treatment, MDA levels in all tissue levels of both rat strains were less in comparison with GEM treatment. GEM caused a significant drop of PON1 activity in serum and liver of Fisher rats, and in liver of Wistar rats. We suggest that GEM, through induction of lipid peroxidation, caused the damage of hepatocytes with consequent reduction of PON1 synthesis. The increase in PON1 activity in serum and tissues of both rat strains 10 days after withdrawal of GEM treatment shows the fast recovery of enzyme synthesis. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

CONKO-005: Adjuvant Chemotherapy With Gemcitabine Plus Erlotinib Versus Gemcitabine Alone in Patients After R0 Resection of Pancreatic Cancer: A Multicenter Randomized Phase III Trial.

PubMed

Sinn, Marianne; Bahra, Marcus; Liersch, Torsten; Gellert, Klaus; Messmann, Helmut; Bechstein, Wolf; Waldschmidt, Dirk; Jacobasch, Lutz; Wilhelm, Martin; Rau, Bettina M; Grützmann, Robert; Weinmann, Arndt; Maschmeyer, Georg; Pelzer, Uwe; Stieler, Jens M; Striefler, Jana K; Ghadimi, Michael; Bischoff, Sven; Dörken, Bernd; Oettle, Helmut; Riess, Hanno

2017-10-10

Purpose Gemcitabine is standard of care in the adjuvant treatment of resectable pancreatic ductal adenocarcinoma (PDAC). The epidermal growth factor receptor tyrosine kinase inhibitor erlotinib in combination with gemcitabine has shown efficacy in the treatment of advanced PDAC and was considered to improve survival in patients with primarily resectable PDAC after R0 resection. Patients and Methods In an open-label, multicenter trial, patients were randomly assigned to one of two study arms: gemcitabine 1,000 mg/m 2 days 1, 8, 15, every 4 weeks plus erlotinib 100 mg once per day (GemErlo) or gemcitabine (Gem) alone for six cycles. The primary end point of the study was to improve disease-free survival (DFS) from 14 to 18 months by adding erlotinib to gemcitabine. Results In all, 436 patients were randomly assigned at 57 study centers between April 2008 and July 2013. A total of 361 instances (83%) of disease recurrence were observed after a median follow-up of 54 months. Median treatment duration was 22 weeks in both arms. There was no difference in median DFS (GemErlo 11.4 months; Gem 11.4 months) or median overall survival (GemErlo 24.5 months; Gem 26.5 months). There was a trend toward long-term survival in favor of GemErlo (estimated survival after 1, 2, and 5 years for GemErlo was 77%, 53%, and 25% v 79%, 54%, and 20% for Gem, respectively). The occurrence or the grade of rash was not associated with a better survival in the GemErlo arm. Conclusion To the best of our knowledge, CONKO-005 is the first study to investigate the combination of chemotherapy and a targeted therapy in the adjuvant treatment of PDAC. GemErlo for 24 weeks did not improve DFS or overall survival over Gem.

Depletion of atmospheric gaseous elemental mercury by plant uptake at Mt. Changbai, Northeast China

NASA Astrophysics Data System (ADS)

Fu, Xuewu; Zhu, Wei; Zhang, Hui; Sommar, Jonas; Yu, Ben; Yang, Xu; Wang, Xun; Lin, Che-Jen; Feng, Xinbin

2016-10-01

There exists observational evidence that gaseous elemental mercury (GEM) can be readily removed from the atmosphere via chemical oxidation followed by deposition in the polar and sub-polar regions, free troposphere, lower stratosphere, and marine boundary layer under specific environmental conditions. Here we report GEM depletions in a temperate mixed forest at Mt. Changbai, Northeast China. The strong depletions occurred predominantly at night during the leaf-growing season and in the absence of gaseous oxidized mercury (GOM) enrichment (GOM < 3 pg m-3). Vertical gradients of decreasing GEM concentrations from layers above to under forest canopy suggest in situ loss of GEM to forest canopy at Mt. Changbai. Foliar GEM flux measurements showed that the foliage of two predominant tree species is a net sink of GEM at night, with a mean flux of -1.8 ± 0.3 ng m2 h-1 over Fraxinus mandshurica (deciduous tree species) and -0.1 ± 0.2 ng m2 h-1 over Pinus Koraiensis (evergreen tree species). Daily integrated GEM δ202Hg, Δ199Hg, and Δ200Hg at Mt. Changbai during 8-18 July 2013 ranged from -0.34 to 0.91 ‰, from -0.11 to -0.04 ‰ and from -0.06 to 0.01 ‰, respectively. A large positive shift in GEM δ202Hg occurred during the strong GEM depletion events, whereas Δ199Hg and Δ200Hg remained essentially unchanged. The observational findings and box model results show that uptake of GEM by forest canopy plays a predominant role in the GEM depletion at Mt. Changbai forest. Such depletion events of GEM are likely to be a widespread phenomenon, suggesting that the forest ecosystem represents one of the largest sinks ( ˜ 1930 Mg) of atmospheric Hg on a global scale.

3D imaging of particle tracks in Solid State Nuclear Track Detectors

NASA Astrophysics Data System (ADS)

Wertheim, D.; Gillmore, G.; Brown, L.; Petford, N.

2009-04-01

Inhalation of radon gas (222Rn) and associated ionizing decay products is known to cause lung cancer in human. In the U.K., it has been suggested that 3 to 5 % of total lung cancer deaths can be linked to elevated radon concentrations in the home and/or workplace. Radon monitoring in buildings is therefore routinely undertaken in areas of known risk. Indeed, some organisations such as the Radon Council in the UK and the Environmental Protection Agency in the USA, advocate a ‘to test is best' policy. Radon gas occurs naturally, emanating from the decay of 238U in rock and soils. Its concentration can be measured using CR?39 plastic detectors which conventionally are assessed by 2D image analysis of the surface; however there can be some variation in outcomes / readings even in closely spaced detectors. A number of radon measurement methods are currently in use (for examples, activated carbon and electrets) but the most widely used are CR?39 solid state nuclear track?etch detectors (SSNTDs). In this technique, heavily ionizing alpha particles leave tracks in the form of radiation damage (via interaction between alpha particles and the atoms making up the CR?39 polymer). 3D imaging of the tracks has the potential to provide information relating to angle and energy of alpha particles but this could be time consuming. Here we describe a new method for rapid high resolution 3D imaging of SSNTDs. A ‘LEXT' OLS3100 confocal laser scanning microscope was used in confocal mode to successfully obtain 3D image data on four CR?39 plastic detectors. 3D visualisation and image analysis enabled characterisation of track features. This method may provide a means of rapid and detailed 3D analysis of SSNTDs. Keywords: Radon; SSNTDs; confocal laser scanning microscope; 3D imaging; LEXT

Use of short-term breath measures to estimate daily methane production by cattle.

PubMed

Velazco, J I; Mayer, D G; Zimmerman, S; Hegarty, R S

2016-01-01

Methods to measure enteric methane (CH4) emissions from individual ruminants in their production environment are required to validate emission inventories and verify mitigation claims. Estimates of daily methane production (DMP) based on consolidated short-term emission measurements are developing, but method verification is required. Two cattle experiments were undertaken to test the hypothesis that DMP estimated by averaging multiple short-term breath measures of methane emission rate did not differ from DMP measured in respiration chambers (RC). Short-term emission rates were obtained from a GreenFeed Emissions Monitoring (GEM) unit, which measured emission rate while cattle consumed a dispensed supplement. In experiment 1 (Expt. 1), four non-lactating cattle (LW=518 kg) were adapted for 18 days then measured for six consecutive periods. Each period consisted of 2 days of ad libitum intake and GEM emission measurement followed by 1 day in the RC. A prototype GEM unit releasing water as an attractant (GEM water) was also evaluated in Expt. 1. Experiment 2 (Expt. 2) was a larger study based on similar design with 10 cattle (LW=365 kg), adapted for 21 days and GEM measurement was extended to 3 days in each of the six periods. In Expt. 1, there was no difference in DMP estimated by the GEM unit relative to the RC (209.7 v. 215.1 g CH(4)/day) and no difference between these methods in methane yield (MY, 22.7 v. 23.7 g CH(4)/kg of dry matter intake, DMI). In Expt. 2, the correlation between GEM and RC measures of DMP and MY were assessed using 95% confidence intervals, with no difference in DMP or MY between methods and high correlations between GEM and RC measures for DMP (r=0.85; 215 v. 198 g CH(4)/day SEM=3.0) and for MY (r=0.60; 23.8 v. 22.1 g CH(4)/kg DMI SEM=0.42). When data from both experiments was combined neither DMP nor MY differed between GEM- and RC-based measures (P>0.05). GEM water-based estimates of DMP and MY were lower than RC and GEM (P<0.05). Cattle accessed the GEM water unit with similar frequency to the GEM unit (2.8 v. 3.5 times/day, respectively) but eructation frequency was reduced from 1.31 times/min (GEM) to once every 2.6 min (GEM water). These studies confirm the hypothesis that DMP estimated by averaging multiple short-term breath measures of methane emission rate using GEM does not differ from measures of DMP obtained from RCs. Further, combining many short-term measures of methane production rate during supplement consumption provides an estimate of DMP, which can be usefully applied in estimating MY.

The ALICE Transition Radiation Detector: Construction, operation, and performance

DOE PAGES

Acharya, S; Adam, J; Adamova, D; ...

2017-09-21

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this article, the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction.more » The triggering capability is demonstrated both for jet, light nuclei, and electron selection.« less

The ALICE Transition Radiation Detector: Construction, operation, and performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acharya, S; Adam, J; Adamova, D

The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this article, the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction.more » The triggering capability is demonstrated both for jet, light nuclei, and electron selection.« less

Instrument performance of a radon measuring system with the alpha-track detection technique.

PubMed

Tokonami, S; Zhuo, W; Ryuo, H; Yonehara, H; Yamada, Y; Shimo, M

2003-01-01

An instrument performance test has been carried out for a radon measuring system made in Hungary. The system measures radon using the alpha-track detection technique. It consists of three parts: the passive detector, the etching unit and the evaluation unit. A CR-39 detector is used as the radiation detector. Alpha-track reading and data analysis are carried out after chemical etching. The following subjects were examined in the present study: (1) radon sensitivity, (2) performance of etching and evaluation processes and (3) thoron sensitivity. The radon sensitivity of 6.9 x 10(-4) mm(-2) (Bq m(-3) d)(-1) was acceptable for practical application. The thoron sensitivity was estimated to be as low as 3.3 x 10(-5) mm(-2) (Bq m(-3) d)(-1) from the experimental study.

Great Explorations in Math and Science[R] (GEMS[R]) Space Science. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2012

2012-01-01

"Great Explorations in Math and Science[R] (GEMS[R]) Space Science" is an instructional sequence for grades 3-5 that covers fundamental concepts, including planetary sizes and distance, the Earth's shape and movement, gravity, and moon phases and eclipses. Part of the "GEMS"[R] core curriculum, "GEMS[R] Space Science"…

Possible Gems and Ultra-Fine Grained Polyphase Units in Comet Wild 2.

NASA Technical Reports Server (NTRS)

Gainsforth, Z.; Butterworth, A. L.; Jilly-Rehak, C. E.; Westphal, A. J.; Brownlee, D. E.; Joswiak, D.; Ogliore, R. C.; Zolensky, M. E.; Bechtel, H. A.; Ebel, D. S.;

On the Origin of GEMS

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.

2004-01-01

GEMS (glass with embedded metal and sulfides) are a major component of anhydrous interplanetary dust particles (IDPs) their physical and chemical characteristics show marked similarities to contemporary interstellar dust. Recent oxygen isotopic measurements confirm that at least a small fraction (less than 5%) of GEMS are demonstrably presolar, while the remainder have ratios that are indistinguishable from solar values. GEMS with solar oxygen isotopic compositions either (1) had their isotopic compositions homogenized through processing in the interstellar medium (ISM), or (2) formed in the early solar system. Isotopic homogenization necessarily implies chemical homogenization, so (interstellar) GEMS compositions should reflect the average composition of dust in the local ISM. We performed a systematic examination of the bulk chemistry of GEMS in primitive IDPs in order to test this hypothesis.

Search for lightly ionizing particles with the MACRO detector

NASA Astrophysics Data System (ADS)

Ambrosio, M.; Antolini, R.; Auriemma, G.; Bakari, D.; Baldini, A.; Barbarino, G. C.; Barish, B. C.; Battistoni, G.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bisi, V.; Bloise, C.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Carboni, M.; Cecchini, S.; Cei, F.; Chiarella, V.; Choudhary, B. C.; Coutu, S.; de Cataldo, G.; Dekhissi, H.; de Marzo, C.; de Mitri, I.; Derkaoui, J.; de Vincenzi, M.; di Credico, A.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giorgini, M.; Grassi, M.; Gray, L.; Grillo, A.; Guarino, F.; Gustavino, C.; Habig, A.; Hanson, K.; Heinz, R.; Iarocci, E.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D. S.; Lipari, P.; Longley, N. P.; Longo, M. J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M. N.; Michael, D. G.; Mikheyev, S.; Miller, L.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolò, D.; Nolty, R.; Orth, C.; Okada, C.; Osteria, G.; Ouchrif, M.; Palamara, O.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C. W.; Perrone, L.; Petrera, S.; Pistilli, P.; Popa, V.; Rainò, A.; Reynoldson, J.; Ronga, F.; Satriano, C.; Satta, L.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Serra, P.; Sioli, M.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J. L.; Sulak, L. R.; Surdo, A.; Tarlè, G.; Togo, V.; Vakili, M.; Vilela, E.; Walter, C. W.; Webb, R.

2000-09-01

A search for lightly ionizing particles has been performed with the MACRO detector. This search was sensitive to particles with charges between 15 e and close to the charge of an electron, with β between approximately 0.25 and 1.0. Unlike previous searches both single track events and tracks buried within high multiplicity muon showers were examined. In a period of approximately one year no candidates were observed. Assuming an isotropic flux, for the single track sample this corresponds to a 90% C.L. upper flux limit Φ<=9.2×10-15 cm-2 s-1 sr-1.

Tracking-Learning-Detection.

PubMed

Kalal, Zdenek; Mikolajczyk, Krystian; Matas, Jiri

2012-07-01

This paper investigates long-term tracking of unknown objects in a video stream. The object is defined by its location and extent in a single frame. In every frame that follows, the task is to determine the object's location and extent or indicate that the object is not present. We propose a novel tracking framework (TLD) that explicitly decomposes the long-term tracking task into tracking, learning, and detection. The tracker follows the object from frame to frame. The detector localizes all appearances that have been observed so far and corrects the tracker if necessary. The learning estimates the detector's errors and updates it to avoid these errors in the future. We study how to identify the detector's errors and learn from them. We develop a novel learning method (P-N learning) which estimates the errors by a pair of "experts": (1) P-expert estimates missed detections, and (2) N-expert estimates false alarms. The learning process is modeled as a discrete dynamical system and the conditions under which the learning guarantees improvement are found. We describe our real-time implementation of the TLD framework and the P-N learning. We carry out an extensive quantitative evaluation which shows a significant improvement over state-of-the-art approaches.

Study of cluster shapes in a monolithic active pixel detector

NASA Astrophysics Data System (ADS)

Maçzewski, ł.; Adamus, M.; Ciborowski, J.; Grzelak, G.; łużniak, P.; Nieżurawski, P.; Żarnecki, A. F.

2009-11-01

Beamstrahlung will constitute an important source of background in a pixel vertex detector at the future International Linear Collider. Electron and positron tracks of this origin impact the pixel planes at angles generally larger than those of secondary hadrons and the corresponding clusters are elongated. We report studies of cluster characteristics using test beam electron tracks incident at various angles on a MIMOSA-5 monolithic active pixel sensor matrix.

Development of Ultra-Fast Silicon Detectors for 4D tracking

NASA Astrophysics Data System (ADS)

Staiano, A.; Arcidiacono, R.; Boscardin, M.; Dalla Betta, G. F.; Cartiglia, N.; Cenna, F.; Ferrero, M.; Ficorella, F.; Mandurrino, M.; Obertino, M.; Pancheri, L.; Paternoster, G.; Sola, V.

2017-12-01

In this contribution we review the progress towards the development of a novel type of silicon detectors suited for tracking with a picosecond timing resolution, the so called Ultra-Fast Silicon Detectors. The goal is to create a new family of particle detectors merging excellent position and timing resolution with GHz counting capabilities, very low material budget, radiation resistance, fine granularity, low power, insensitivity to magnetic field, and affordability. We aim to achieve concurrent precisions of ~ 10 ps and ~ 10 μm with a 50 μm thick sensor. Ultra-Fast Silicon Detectors are based on the concept of Low-Gain Avalanche Detectors, which are silicon detectors with an internal multiplication mechanism so that they generate a signal which is factor ~10 larger than standard silicon detectors. The basic design of UFSD consists of a thin silicon sensor with moderate internal gain and pixelated electrodes coupled to full custom VLSI chip. An overview of test beam data on time resolution and the impact on this measurement of radiation doses at the level of those expected at HL-LHC is presented. First I-V and C-V measurements on a new FBK sensor production of UFSD, 50 μm thick, with B and Ga, activated at two diffusion temperatures, with and without C co-implantation (in Low and High concentrations), and with different effective doping concentrations in the Gain layer, are shown. Perspectives on current use of UFSD in HEP experiments (UFSD detectors have been installed in the CMS-TOTEM Precision Protons Spectrometer for the forward physics tracking, and are currently taking data) and proposed applications for a MIP timing layer in the HL-LHC upgrade are briefly discussed.

Performance verification of the CMS Phase-1 Upgrade Pixel detector

NASA Astrophysics Data System (ADS)

Veszpremi, V.

2017-12-01

The CMS tracker consists of two tracking systems utilizing semiconductor technology: the inner pixel and the outer strip detectors. The tracker detectors occupy the volume around the beam interaction region between 3 cm and 110 cm in radius and up to 280 cm along the beam axis. The pixel detector consists of 124 million pixels, corresponding to about 2 m 2 total area. It plays a vital role in the seeding of the track reconstruction algorithms and in the reconstruction of primary interactions and secondary decay vertices. It is surrounded by the strip tracker with 10 million read-out channels, corresponding to 200 m 2 total area. The tracker is operated in a high-occupancy and high-radiation environment established by particle collisions in the LHC . The current strip detector continues to perform very well. The pixel detector that has been used in Run 1 and in the first half of Run 2 was, however, replaced with the so-called Phase-1 Upgrade detector. The new system is better suited to match the increased instantaneous luminosity the LHC would reach before 2023. It was built to operate at an instantaneous luminosity of around 2×1034 cm-2s-1. The detector's new layout has an additional inner layer with respect to the previous one; it allows for more efficient tracking with smaller fake rate at higher event pile-up. The paper focuses on the first results obtained during the commissioning of the new detector. It also includes challenges faced during the first data taking to reach the optimal measurement efficiency. Details will be given on the performance at high occupancy with respect to observables such as data-rate, hit reconstruction efficiency, and resolution.

Extratropical Cyclones over Southwestern Atlantic Ocean: Present and Future Climates projected by RegCM4

NASA Astrophysics Data System (ADS)

Reboita, Michelle; Rodrigues, Marcelo; da Rocha, Rosmeri

2017-04-01

This study shows some of the climatological features of the extratropical cyclones in present and future climate over Southwestern Atlantic Ocean (SAO). The projections were carried out with Regional Climate Model (RegCM4) nested in HadGEM2-ES global model outputs and using representative concentration pathway 8.5 (RCP8.5) from the CMIP5. The simulations considered the South America domain suggested by CORDEX, horizontal grid spacing of 50 km, 18 sigma-pressure levels in the vertical. An objective tracking scheme based on cyclonic relative vorticity calculated using the wind at 925 hPa was used to identify the cyclones. All cyclones with relative vorticity lower than the -1.5 x 10-5 s-1 and with lifetime higher or equal 24 hours were included in the climatology. Considering the period from 1979 to 2098, RegCM4 and HadGEM2-ES project a negative trend in the frequency of the extratropical cyclones over SAO, with the biggest negative trend occuring in the latitudinal band between 40°S and 57.5°S. This result can be associated with the southward displacement of the baroclinic zone which contributes to the cyclones move to south leaving the region analyzed. The three subregions with largest cyclogenetic activity discussed in the literature (southeast coast of Brazil - RG1, coast of Uruguay and southern Brazil - RG2; east coast of Argentina - RG3) were better reproduced in RegCM4 than in HadGEM2-ES. Therefore, RegCM4 downscaling ads value in the HadGEM2-ES projections. The frequency of cyclones in present (1979-2005) and future climate (2070-2098) is higher in winter and lower in summer. Regarding the mean characteristics of the cyclones (life time, travel distance, velocity, initial relative vorticity and total average vorticity), both models successfully reproduced those obtained in the reanalysis (NCEP1, NCEP2, CFSR, ERA40 and ERA-Interim) and there are no significant differences in the future climate compared with the present.

Optimum data weighting and error calibration for estimation of gravitational parameters

NASA Technical Reports Server (NTRS)

Lerch, F. J.

1989-01-01

A new technique was developed for the weighting of data from satellite tracking systems in order to obtain an optimum least squares solution and an error calibration for the solution parameters. Data sets from optical, electronic, and laser systems on 17 satellites in GEM-T1 (Goddard Earth Model, 36x36 spherical harmonic field) were employed toward application of this technique for gravity field parameters. Also, GEM-T2 (31 satellites) was recently computed as a direct application of the method and is summarized here. The method employs subset solutions of the data associated with the complete solution and uses an algorithm to adjust the data weights by requiring the differences of parameters between solutions to agree with their error estimates. With the adjusted weights the process provides for an automatic calibration of the error estimates for the solution parameters. The data weights derived are generally much smaller than corresponding weights obtained from nominal values of observation accuracy or residuals. Independent tests show significant improvement for solutions with optimal weighting as compared to the nominal weighting. The technique is general and may be applied to orbit parameters, station coordinates, or other parameters than the gravity model.

Preliminary use of nematic liquid crystal adaptive optics with a 2.16-meter reflecting telescope.

PubMed

Cao, Zhaoliang; Mu, Quanquan; Hu, Lifa; Li, Dayu; Peng, Zenghui; Liu, Yonggang; Xuan, Li

2009-02-16

A nematic liquid crystal adaptive optics system (NLC AOS) was assembled for a 2.16-m telescope to correct for atmospheric turbulence. LC AOS was designed and optimized with Zemax optical software. Second, an adaptive correction experiment was performed in the laboratory to test the performance of the NLC AOS. After the correction, the peak to valley (PV) and root mean square (RMS) of the wavefront were down to 0.2 lambda (lambda=633 nm) and 0.05 lambda, respectively. Finally, the star of Pollux (beta Gem) was tracked using the 2.16-m Reflecting Telescope, and real time correction of the atmospheric turbulence was performed with the NLC AOS. After the adaptive correction, the average PV and RMS of the wavefront were reduced from 11 lambda and 2.5 lambda to 2.3 lambda and 0.6 lambda, respectively. Although the intensity distribution of the beta Gem was converged and its peak was sharp, a halo still existed around the peak. These results indicated that the NLC AOS only partially corrected the vertical atmospheric turbulence. The limitations of our NLC AOS are discussed and some proposals are made.

Tracking rare-isotope beams with microchannel plates

DOE PAGES

Rogers, A. M.; Sanetullaev, A.; Lynch, W. G.; ...

2015-06-06

A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival Limes of ions at the reaction target. Furthermore, the current design is an adaptation of an assembly used for low-energy beams (~1.4 MeV/nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm formore » beam intensities up to 5 x 10 5 pps.« less

Tracking rare-isotope beams with microchannel plates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, A. M.; Sanetullaev, A.; Lynch, W. G.

A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival Limes of ions at the reaction target. Furthermore, the current design is an adaptation of an assembly used for low-energy beams (~1.4 MeV/nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm formore » beam intensities up to 5 x 10 5 pps.« less

An automatic analyzer of solid state nuclear track detectors using an optic RAM as image sensor

NASA Astrophysics Data System (ADS)

Staderini, Enrico Maria; Castellano, Alfredo

1986-02-01

An optic RAM is a conventional digital random access read/write dynamic memory device featuring a quartz windowed package and memory cells regularly ordered on the chip. Such a device is used as an image sensor because each cell retains data stored in it for a time depending on the intensity of the light incident on the cell itself. The authors have developed a system which uses an optic RAM to acquire and digitize images from electrochemically etched CR39 solid state nuclear track detectors (SSNTD) in the track count rate up to 5000 cm -2. On the digital image so obtained, a microprocessor, with appropriate software, performs image analysis, filtering, tracks counting and evaluation.

TPC status for MPD experiment of NICA project

NASA Astrophysics Data System (ADS)

Averyanov, A.; Bazhazhin, A.; Chepurnov, V. F.; Chepurnov, V. V.; Cheremukhina, G.; Chernenko, S.; Fateev, O.; Kiriushin, Yu.; Kolesnikov, A.; Korotkova, A.; Levchanovsky, F.; Lukstins, J.; Movchan, S.; Pilyar, A.; Razin, S.; Ribakov, A.; Samsonov, V.; Vereschagin, S.; Zanevsky, Yu.; Zaporozhets, S.; Zruev, V.

2017-06-01

In a frame of the JINR scientific program on study of hot and dense baryonic matter a new accelerator complex Ion Collider fAcility (NICA) based on the Nuclotron-M is under realization. It will operate at luminosity up to 1027 cm-2s-1 for Au79+ ions. Two interaction points are foreseen at NICA for two detectors which will operate simultaneously. One of these detectors, the Multi-Purpose Detector (MPD), is optimized for investigations of heavy-ion collisions. The Time-Projection Chamber (TPC) is the main tracking detector of the MPD central barrel. It is a well-known detector for 3-dimensional tracking and particle identification for high multiplicity events. The conceptual layout of MPD and detailed description of the design and main working parameters of TPC, the readout system based on MWPC and readout electronics as well as the TPC subsystems and tooling for assembling and integration TPC into MPD are presented.

[Effects of Cultivation Soil Properties on the Transport of Genetically Engineered Microorganism in Huabei Plain].

PubMed

Zhang, Jing; Liu, Ping; Liu, Chun; Chen, Xiao-xuan; Zhang, Lei

2015-12-01

The transport of genetically engineered microorganism (GEM) in the soil is considered to be the important factor influencing the enhanced bioremediation of polluted soil. The transport of an atrazine-degrading GEM and its influencing factors were investigated in the saturated cultivation soil of Huabei Plain. The results showed that horizontal infiltration was the main mechanism of GEM transport in the saturated cultivation soil. The transport process could be simulated using the filtration model. Soil properties showed significant effects on pore water flow and GEM transport in saturated soil. When particle size, porosity and sand component of the soil increased, the hydraulic conductivity constant increased and filtration coefficient of GEM decreased in saturated soil, indicating the reduced retention of GEM in the soil. An increase in infiltration flow also increased hydraulic conductivity constant in saturated soil and consequently decreased filtration coefficient of GEM. When hydraulic conductivity constants ranged from 5.02 m · d⁻¹ to 6.70 m · d⁻¹ in the saturated soil, the filtration coefficients of GEM varied from 0.105 to 0.274. There was a significantly negative correlation between them.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graf, Norman A.; /SLAC

Maximizing the physics performance of detectors being designed for the International Linear Collider, while remaining sensitive to cost constraints, requires a powerful, efficient, and flexible simulation, reconstruction and analysis environment to study the capabilities of a large number of different detector designs. The preparation of Letters Of Intent for the International Linear Collider involved the detailed study of dozens of detector options, layouts and readout technologies; the final physics benchmarking studies required the reconstruction and analysis of hundreds of millions of events. We describe the Java-based software toolkit (org.lcsim) which was used for full event reconstruction and analysis. The componentsmore » are fully modular and are available for tasks from digitization of tracking detector signals through to cluster finding, pattern recognition, track-fitting, calorimeter clustering, individual particle reconstruction, jet-finding, and analysis. The detector is defined by the same xml input files used for the detector response simulation, ensuring the simulation and reconstruction geometries are always commensurate by construction. We discuss the architecture as well as the performance.« less

Does GEM-encoding clinical practice guidelines improve the quality of knowledge bases? A study with the rule-based formalism.

PubMed

Georg, Georg; Séroussi, Brigitte; Bouaud, Jacques

2003-01-01

The aim of this work was to determine whether the GEM-encoding step could improve the representation of clinical practice guidelines as formalized knowledge bases. We used the 1999 Canadian recommendations for the management of hypertension, chosen as the knowledge source in the ASTI project. We first clarified semantic ambiguities of therapeutic sequences recommended in the guideline by proposing an interpretative framework of therapeutic strategies. Then, after a formalization step to standardize the terms used to characterize clinical situations, we created the GEM-encoded instance of the guideline. We developed a module for the automatic derivation of a rule base, BR-GEM, from the instance. BR-GEM was then compared to the rule base, BR-ASTI, embedded within the critic mode of ASTI, and manually built by two physicians from the same Canadian guideline. As compared to BR-ASTI, BR-GEM is more specific and covers more clinical situations. When evaluated on 10 patient cases, the GEM-based approach led to promising results.

The determination of the orbit of the Japanese satellite Ajisai and the GEM-T1 and GEM-T2 gravity field models

NASA Technical Reports Server (NTRS)

Sanchez, Braulio V.

1990-01-01

The Japanese Experimental Geodetic Satellite Ajisai was launched on August 12, 1986. In response to the TOPEX-POSEIDON mission requirements, the GSFC Space Geodesy Branch and its associates are producing improved models of the Earth's gravitational field. With the launch of Ajisai, precise laser data is now available which can be used to test many current gravity models. The testing of the various gravity field models show improvements of more than 70 percent in the orbital fits when using GEM-T1 and GEM-T2 relative to results obtained with the earlier GEM-10B model. The GEM-T2 orbital fits are at the 13-cm level (RMS). The results of the tests with the various versions of the GEM-T1 model indicate that the addition of satellite altimetry and surface gravity anomalies as additional data types should improve future gravity field models.

gem-Difluoroolefination of diaryl ketones and enolizable aldehydes with difluoromethyl 2-pyridyl sulfone: new insights into the Julia-Kocienski reaction.

PubMed

Gao, Bing; Zhao, Yanchuan; Hu, Mingyou; Ni, Chuanfa; Hu, Jinbo

2014-06-16

The direct conversion of diaryl ketones and enolizable aliphatic aldehydes into gem-difluoroalkenes has been a long-standing challenge in organofluorine chemistry. Herein, we report efficient strategies to tackle this problem by using difluoromethyl 2-pyridyl sulfone as a general gem-difluoroolefination reagent. The gem-difluoroolefination of diaryl ketones proceeds by acid-promoted Smiles rearrangement of the carbinol intermediate; the gem-difluoroolefination is otherwise difficult to achieve through a conventional Julia-Kocienski olefination protocol under basic conditions due to the retro-aldol type decomposition of the key intermediate. Efficient gem-difluoroolefination of aliphatic aldehydes was achieved by the use of an amide base generated in situ (from CsF and tris(trimethylsilyl)amine), which diminishes the undesired enolization of aliphatic aldehydes and provides a powerful synthetic method for chemoselective gem-difluoroolefination of multi-carbonyl compounds. Our results provide new insights into the mechanistic understanding of the classical Julia-Kocienski reaction. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diagnostic-management system and test pulse acquisition for WEST plasma measurement system

NASA Astrophysics Data System (ADS)

Wojenski, A.; Kasprowicz, G.; Pozniak, K. T.; Byszuk, A.; Juszczyk, B.; Zabolotny, W.; Zienkiewicz, P.; Chernyshova, M.; Czarski, T.; Mazon, D.; Malard, P.

2014-11-01

This paper describes current status of electronics, firmware and software development for new plasma measurement system for use in WEST facility. The system allows to perform two dimensional plasma visualization (in time) with spectrum measurement. The analog front-end is connected to Gas Electron Multiplier detector (GEM detector). The system architecture have high data throughput due to use of PCI-Express interface, Gigabit Transceivers and sampling frequency of ADC integrated circuits. The hardware is based on several years of experience in building X-ray spectrometer system for Joint European Torus (JET) facility. Data streaming is done using Artix7 FPGA devices. The system in basic configuration can work with up to 256 channels, while the maximum number of measurement channels is 2048. Advanced firmware for the FPGA is required in order to perform high speed data streaming and analog signal sampling. Diagnostic system management has been developed in order to configure measurement system, perform necessary calibration and prepare hardware for data acquisition.

MICROROC: MICRO-mesh gaseous structure Read-Out Chip

NASA Astrophysics Data System (ADS)

Adloff, C.; Blaha, J.; Chefdeville, M.; Dalmaz, A.; Drancourt, C.; Dulucq, F.; Espargilière, A.; Gaglione, R.; Geffroy, N.; Jacquemier, J.; Karyotakis, Y.; Martin-Chassard, G.; Prast, J.; Seguin-Moreau, N.; de La Taille, Ch; Vouters, G.

2012-01-01

MICRO MEsh GAseous Structure (MICROMEGAS) and Gas Electron Multipliers (GEM) detectors are two candidates for the active medium of a Digital Hadronic CALorimeter (DHCAL) as part of a high energy physics experiment at a future linear collider (ILC/CLIC). Physics requirements lead to a highly granular hadronic calorimeter with up to thirty million channels with probably only hit information (digital readout calorimeter). To validate the concept of digital hadronic calorimetry with such small cell size, the construction and test of a cubic meter technological prototype, made of 40 planes of one square meter each, is necessary. This technological prototype would contain about 400 000 electronic channels, thus requiring the development of front-end ASIC. Based on the experience gained with previous ASIC that were mounted on detectors and tested in particle beams, a new ASIC called MICROROC has been developped. This paper summarizes the caracterisation campaign that was conducted on this new chip as well as its integration into a large area Micromegas chamber of one square meter.

First results of the silicon telescope using an 'artificial retina' for fast track finding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neri, N.; Abba, A.; Caponio, F.

We present the first results of the prototype of a silicon tracker with trigger capabilities based on a novel approach for fast track finding. The working principle of the 'artificial retina' is inspired by the processing of visual images by the brain and it is based on extensive parallelization of data distribution and pattern recognition. The algorithm has been implemented in commercial FPGAs in three main logic modules: a switch for the routing of the detector hits, a pool of engines for the digital processing of the hits, and a block for the calculation of the track parameters. The architecturemore » is fully pipelined and allows the reconstruction of real-time tracks with a latency less then 100 clock cycles, corresponding to 0.25 microsecond at 400 MHz clock. The silicon telescope consists of 8 layers of single-sided silicon strip detectors with 512 strips each. The detector size is about 10 cm x 10 cm and the strip pitch is 183 μm. The detectors are read out by the Beetle chip, a custom ASICs developed for LHCb, which provides the measurement of the hit position and pulse height of 128 channels. The 'artificial retina' algorithm has been implemented on custom data acquisition boards based on FPGAs Xilinx Kintex 7 lx160. The parameters of the tracks detected are finally transferred to host PC via USB 3.0. The boards manage the read-out ASICs and the sampling of the analog channels. The read-out is performed at 40 MHz on 4 channels for each ASIC that corresponds to a decoding of the telescope information at 1.1 MHz. We report on the first results of the fast tracking device and compare with simulations. (authors)« less

Dst Index in the 2008 GEM Modeling Challenge - Model Performance for Moderate and Strong Magnetic Storms

NASA Technical Reports Server (NTRS)

Rastaetter, Lutz; Kuznetsova, Maria; Hesse, Michael; Chulaki, Anna; Pulkkinen, Antti; Ridley, Aaron J.; Gombosi, Tamas; Vapirev, Alexander; Raeder, Joachim; Wiltberger, Michael James;

Current understanding of the driving mechanisms for spatiotemporal variations of atmospheric speciated mercury: a review

NASA Astrophysics Data System (ADS)

Mao, Huiting; Cheng, Irene; Zhang, Leiming

2016-10-01

Atmospheric mercury (Hg) is a global pollutant and thought to be the main source of mercury in oceanic and remote terrestrial systems, where it becomes methylated and bioavailable; hence, atmospheric mercury pollution has global consequences for both human and ecosystem health. Understanding of spatial and temporal variations of atmospheric speciated mercury can advance our knowledge of mercury cycling in various environments. This review summarized spatiotemporal variations of total gaseous mercury or gaseous elemental mercury (TGM/GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM) in various environments including oceans, continents, high elevation, the free troposphere, and low to high latitudes. In the marine boundary layer (MBL), the oxidation of GEM was generally thought to drive the diurnal and seasonal variations of TGM/GEM and GOM in most oceanic regions, leading to lower GEM and higher GOM from noon to afternoon and higher GEM during winter and higher GOM during spring-summer. At continental sites, the driving mechanisms of TGM/GEM diurnal patterns included surface and local emissions, boundary layer dynamics, GEM oxidation, and for high-elevation sites mountain-valley winds, while oxidation of GEM and entrainment of free tropospheric air appeared to control the diurnal patterns of GOM. No pronounced diurnal variation was found for Tekran measured PBM at MBL and continental sites. Seasonal variations in TGM/GEM at continental sites were attributed to increased winter combustion and summertime surface emissions, and monsoons in Asia, while those in GOM were controlled by GEM oxidation, free tropospheric transport, anthropogenic emissions, and wet deposition. Increased PBM at continental sites during winter was primarily due to local/regional coal and wood combustion emissions. Long-term TGM measurements from the MBL and continental sites indicated an overall declining trend. Limited measurements suggested TGM/GEM increasing from the Southern Hemisphere (SH) to the Northern Hemisphere (NH) due largely to the vast majority of mercury emissions in the NH, and the latitudinal gradient was insignificant in summer probably as a result of stronger meridional mixing. Aircraft measurements showed no significant vertical variation in GEM over the field campaign regions; however, depletion of GEM was observed in stratospherically influenced air masses. In examining the remaining questions and issues, recommendations for future research needs were provided, and among them is the most imminent need for GOM speciation measurements and fundamental understanding of multiphase redox kinetics.

GOSSIP: A vertex detector combining a thin gas layer as signal generator with a CMOS readout pixel array

NASA Astrophysics Data System (ADS)

Campbell, M.; Heijne, E. H. M.; Llopart, X.; Colas, P.; Giganon, A.; Giomataris, Y.; Chefdeville, M.; Colijn, A. P.; Fornaini, A.; van der Graaf, H.; Kluit, P.; Timmermans, J.; Visschers, J. L.; Schmitz, J.

2006-05-01

A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50 μm above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as δ-rays. With a gas layer thickness of only 1 mm, the device could be applied as vertex detector, outperforming all Si-based detectors.

FastSim: A Fast Simulation for the SuperB Detector

NASA Astrophysics Data System (ADS)

Andreassen, R.; Arnaud, N.; Brown, D. N.; Burmistrov, L.; Carlson, J.; Cheng, C.-h.; Di Simone, A.; Gaponenko, I.; Manoni, E.; Perez, A.; Rama, M.; Roberts, D.; Rotondo, M.; Simi, G.; Sokoloff, M.; Suzuki, A.; Walsh, J.

2011-12-01

We have developed a parameterized (fast) simulation for detector optimization and physics reach studies of the proposed SuperB Flavor Factory in Italy. Detector components are modeled as thin sections of planes, cylinders, disks or cones. Particle-material interactions are modeled using simplified cross-sections and formulas. Active detectors are modeled using parameterized response functions. Geometry and response parameters are configured using xml files with a custom-designed schema. Reconstruction algorithms adapted from BaBar are used to build tracks and clusters. Multiple sources of background signals can be merged with primary signals. Pattern recognition errors are modeled statistically by randomly misassigning nearby tracking hits. Standard BaBar analysis tuples are used as an event output. Hadronic B meson pair events can be simulated at roughly 10Hz.

Commissioning of the ATLAS Muon Spectrometer with cosmic rays

NASA Astrophysics Data System (ADS)

Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; Acharya, B. S.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adorisio, C.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahmed, H.; Ahsan, M.; Aielli, G.; Akdogan, T.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Aktas, A.; Alam, M. S.; Alam, M. A.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Aliyev, M.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alviggi, M. G.; Amako, K.; Amelung, C.; Amorim, A.; Amorós, G.; Amram, N.; Anastopoulos, C.; Andeen, T.; Anders, C. F.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angerami, A.; Anghinolfi, F.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonelli, S.; Antos, J.; Antunovic, B.; Anulli, F.; Aoun, S.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Archambault, J. P.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, T.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnault, C.; Artamonov, A.; Arutinov, D.; Asai, M.; Asai, S.; Asfandiyarov, R.; Ask, S.; Åsman, B.; Asner, D.; Asquith, L.; Assamagan, K.; Astbury, A.; Astvatsatourov, A.; Atoian, G.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Austin, N.; Avolio, G.; Avramidou, R.; Axen, D.; Ay, C.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Badescu, E.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, M. D.; Baker, S.; Dos Santos Pedrosa, F. Baltasar; Banas, E.; Banerjee, P.; Banerjee, S.; Banfi, D.; Bangert, A.; Bansal, V.; Baranov, S. P.; Baranov, S.; Barashkou, A.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Bartoldus, R.; Bartsch, D.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Bazalova, M.; Beare, B.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Becerici, N.; Bechtle, P.; Beck, G. A.; Beck, H. P.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bee, C.; Begel, M.; Harpaz, S. Behar; Behera, P. K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellina, F.; Bellomo, M.; Belloni, A.; Belotskiy, K.; Beltramello, O.; Ben Ami, S.; Benary, O.; Benchekroun, D.; Bendel, M.; Benedict, B. H.; Benekos, N.; Benhammou, Y.; Benincasa, G. P.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertin, A.; Besana, M. I.; Besson, N.; Bethke, S.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bitenc, U.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blanchot, G.; Blocker, C.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bocci, A.; Boehler, M.; Boek, J.; Boelaert, N.; Böser, S.; Bogaerts, J. A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bondarenko, V. G.; Bondioli, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borroni, S.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boulahouache, C.; Bourdarios, C.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Braem, A.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brodet, E.; Bromberg, C.; Brooijmans, G.; Brooks, W. K.; Brown, G.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bucci, F.; Buchanan, J.; Buchholz, P.; Buckley, A. G.; Budagov, I. A.; Budick, B.; Büscher, V.; Bugge, L.; Bulekov, O.; Bunse, M.; Buran, T.; Burckhart, H.; Burdin, S.; Burgess, T.; Burke, S.; Busato, E.; Bussey, P.; Buszello, C. P.; Butin, F.; Butler, B.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Byatt, T.; Caballero, J.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Calvet, D.; Camarri, P.; Cameron, D.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Capasso, L.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Caramarcu, C.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, B.; Caron, S.; Carrillo Montoya, G. D.; Carron Montero, S.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Cascella, M.; Castaneda Hernandez, A. M.; Castaneda-Miranda, E.; Castillo Gimenez, V.; Castro, N. F.; Cataldi, G.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Cattani, G.; Caughron, S.; Cauz, D.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chan, K.; Chapman, J. D.; Chapman, J. W.; Chareyre, E.; Charlton, D. G.; Chavda, V.; Cheatham, S.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chen, H.; Chen, S.; Chen, X.; Cheplakov, A.; Chepurnov, V. F.; Cherkaoui El Moursli, R.; Tcherniatine, V.; Chesneanu, D.; Cheu, E.; Cheung, S. L.; Chevalier, L.; Chevallier, F.; Chiarella, V.; Chiefari, G.; Chikovani, L.; Childers, J. T.; Chilingarov, A.; Chiodini, G.; Chizhov, V.; Choudalakis, G.; Chouridou, S.; Christidi, I. A.; Christov, A.; Chromek-Burckhart, D.; Chu, M. L.; Chudoba, J.; Ciapetti, G.; Ciftci, A. K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciobotaru, M. D.; Ciocca, C.; Ciocio, A.; Cirilli, M.; Citterio, M.; Clark, A.; Clark, P. J.; Cleland, W.; Clemens, J. C.; Clement, B.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coggeshall, J.; Cogneras, E.; Colijn, A. P.; Collard, C.; Collins, N. J.; Collins-Tooth, C.; Collot, J.; Colon, G.; Conde Muiño, P.; Coniavitis, E.; Consonni, M.; Constantinescu, S.; Conta, C.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cooper-Smith, N. J.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Costin, T.; Côté, D.; Coura Torres, R.; Courneyea, L.; Cowan, G.; Cowden, C.; Cox, B. E.; Cranmer, K.; Cranshaw, J.; Cristinziani, M.; Crosetti, G.; Crupi, R.; Crépé-Renaudin, S.; Almenar, C. Cuenca; Cuhadar Donszelmann, T.; Curatolo, M.; Curtis, C. J.; Cwetanski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; D'Orazio, A.; da Via, C.; Dabrowski, W.; Dai, T.; Dallapiccola, C.; Dallison, S. J.; Daly, C. H.; Dam, M.; Danielsson, H. O.; Dannheim, D.; Dao, V.; Darbo, G.; Darlea, G. L.; Davey, W.; Davidek, T.; Davidson, N.; Davidson, R.; Davies, M.; Davison, A. R.; Dawson, I.; Daya, R. K.; de, K.; de Asmundis, R.; de Castro, S.; de Castro Faria Salgado, P. E.; de Cecco, S.; de Graat, J.; de Groot, N.; de Jong, P.; de Mora, L.; de Oliveira Branco, M.; de Pedis, D.; de Salvo, A.; de Sanctis, U.; de Santo, A.; de Vivie de Regie, J. B.; de Zorzi, G.; Dean, S.; Dedovich, D. V.; Degenhardt, J.; Dehchar, M.; Del Papa, C.; Del Peso, J.; Del Prete, T.; Dell'Acqua, A.; Dell'Asta, L.; Della Pietra, M.; Della Volpe, D.; Delmastro, M.; Delsart, P. A.; Deluca, C.; Demers, S.; Demichev, M.; Demirkoz, B.; Deng, J.; Deng, W.; Denisov, S. P.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deviveiros, P. O.; Dewhurst, A.; Dewilde, B.; Dhaliwal, S.; Dhullipudi, R.; di Ciaccio, A.; di Ciaccio, L.; di Domenico, A.; di Girolamo, A.; di Girolamo, B.; di Luise, S.; di Mattia, A.; di Nardo, R.; di Simone, A.; di Sipio, R.; Diaz, M. A.; Diblen, F.; Diehl, E. B.; Dietrich, J.; Dietzsch, T. A.; Diglio, S.; Dindar Yagci, K.; Dingfelder, J.; Dionisi, C.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djilkibaev, R.; Djobava, T.; Do Vale, M. A. B.; Do Valle Wemans, A.; Doan, T. K. O.; Dobos, D.; Dobson, E.; Dobson, M.; Doglioni, C.; Doherty, T.; Dolejsi, J.; Dolenc, I.; Dolezal, Z.; Dolgoshein, B. A.; Dohmae, T.; Donega, M.; Donini, J.; Dopke, J.; Doria, A.; Dos Anjos, A.; Dotti, A.; Dova, M. T.; Doxiadis, A.; Doyle, A. T.; Drasal, Z.; Dris, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Dudarev, A.; Dudziak, F.; Dührssen, M.; Duflot, L.; Dufour, M.-A.; Dunford, M.; Duran Yildiz, H.; Dushkin, A.; Duxfield, R.; Dwuznik, M.; Düren, M.; Ebenstein, W. L.; Ebke, J.; Eckweiler, S.; Edmonds, K.; Edwards, C. A.; Egorov, K.; Ehrenfeld, W.; Ehrich, T.; Eifert, T.; Eigen, G.; Einsweiler, K.; Eisenhandler, E.; Ekelof, T.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellinghaus, F.; Ellis, K.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Engelmann, R.; Engl, A.; Epp, B.; Eppig, A.; Erdmann, J.; Ereditato, A.; Eriksson, D.; Ermoline, I.; Ernst, J.; Ernst, M.; Ernwein, J.; Errede, D.; Errede, S.; Ertel, E.; Escalier, M.; Escobar, C.; Espinal Curull, X.; Esposito, B.; Etienvre, A. I.; Etzion, E.; Evans, H.; Fabbri, L.; Fabre, C.; Facius, K.; Fakhrutdinov, R. M.; Falciano, S.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farley, J.; Farooque, T.; Farrington, S. M.; Farthouat, P.; Fassnacht, P.; Fassouliotis, D.; Fatholahzadeh, B.; Fayard, L.; Fayette, F.; Febbraro, R.; Federic, P.; Fedin, O. L.; Fedorko, W.; Feligioni, L.; Felzmann, C. U.; Feng, C.; Feng, E. J.; Fenyuk, A. B.; Ferencei, J.; Ferland, J.; Fernandes, B.; Fernando, W.; Ferrag, S.; Ferrando, J.; Ferrara, V.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferrer, A.; Ferrer, M. L.; Ferrere, D.; Ferretti, C.; Fiascaris, M.; Fiedler, F.; Filipčič, A.; Filippas, A.; Filthaut, F.; Fincke-Keeler, M.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, G.; Fisher, M. J.; Flechl, M.; Fleck, I.; Fleckner, J.; Fleischmann, P.; Fleischmann, S.; Flick, T.; Flores Castillo, L. R.; Flowerdew, M. J.; Martin, T. Fonseca; Formica, A.; Forti, A.; Fortin, D.; Fournier, D.; Fowler, A. J.; Fowler, K.; Fox, H.; Francavilla, P.; Franchino, S.; Francis, D.; Franklin, M.; Franz, S.; Fraternali, M.; Fratina, S.; Freestone, J.; French, S. T.; Froeschl, R.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gadfort, T.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Galea, C.; Gallas, E. J.; Gallo, V.; Gallop, B. J.; Gallus, P.; Galyaev, E.; Gan, K. K.; Gao, Y. S.; Gaponenko, A.; Garcia-Sciveres, M.; García, C.; Navarro, J. E. García; Gardner, R. W.; Garelli, N.; Garitaonandia, H.; Garonne, V.; Gatti, C.; Gaudio, G.; Gautard, V.; Gauzzi, P.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gazis, E. N.; Ge, P.; Gee, C. N. P.; Geich-Gimbel, Ch.; Gellerstedt, K.; Gemme, C.; Genest, M. H.; Gentile, S.; Georgatos, F.; George, S.; Gershon, A.; Ghazlane, H.; Ghodbane, N.; Giacobbe, B.; Giagu, S.; Giakoumopoulou, V.; Giangiobbe, V.; Gianotti, F.; Gibbard, B.; Gibson, A.; Gibson, S. M.; Gilbert, L. 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P.; Poulard, G.; Poveda, J.; Prabhu, R.; Pralavorio, P.; Prasad, S.; Pravahan, R.; Pribyl, L.; Price, D.; Price, L. E.; Prichard, P. M.; Prieur, D.; Primavera, M.; Prokofiev, K.; Prokoshin, F.; Protopopescu, S.; Proudfoot, J.; Prudent, X.; Przysiezniak, H.; Psoroulas, S.; Ptacek, E.; Puigdengoles, C.; Purdham, J.; Purohit, M.; Puzo, P.; Pylypchenko, Y.; Qi, M.; Qian, J.; Qian, W.; Qin, Z.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Quinonez, F.; Raas, M.; Radeka, V.; Radescu, V.; Radics, B.; Rador, T.; Ragusa, F.; Rahal, G.; Rahimi, A. M.; Rajagopalan, S.; Rammensee, M.; Rammes, M.; Rauscher, F.; Rauter, E.; Raymond, M.; Read, A. L.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Reinherz-Aronis, E.; Reinsch, A.; Reisinger, I.; Reljic, D.; Rembser, C.; Ren, Z. L.; Renkel, P.; Rescia, S.; Rescigno, M.; Resconi, S.; Resende, B.; Reznicek, P.; Rezvani, R.; Richards, A.; Richards, R. A.; Richter, R.; Richter-Was, E.; Ridel, M.; Rijpstra, M.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Rios, R. R.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Roa Romero, D. A.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robinson, M.; Robson, A.; Rocha de Lima, J. G.; Roda, C.; Dos Santos, D. Roda; Rodriguez, D.; Garcia, Y. Rodriguez; Roe, S.; Røhne, O.; Rojo, V.; Rolli, S.; Romaniouk, A.; Romanov, V. M.; Romeo, G.; Romero Maltrana, D.; Roos, L.; Ros, E.; Rosati, S.; Rosenbaum, G. A.; Rosselet, L.; Rossetti, V.; Rossi, L. P.; Rotaru, M.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Ruckert, B.; Ruckstuhl, N.; Rud, V. I.; Rudolph, G.; Rühr, F.; Ruggieri, F.; Ruiz-Martinez, A.; Rumyantsev, L.; Rurikova, Z.; Rusakovich, N. A.; Rutherfoord, J. P.; Ruwiedel, C.; Ruzicka, P.; Ryabov, Y. F.; Ryan, P.; Rybkin, G.; Rzaeva, S.; Saavedra, A. F.; Sadrozinski, H. F.-W.; Sadykov, R.; Sakamoto, H.; Salamanna, G.; Salamon, A.; Saleem, M. S.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvachua Ferrando, B. M.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Samset, B. H.; Sandaker, H.; Sander, H. G.; Sanders, M. P.; Sandhoff, M.; Sandhu, P.; Sandstroem, R.; Sandvoss, S.; Sankey, D. P. C.; Sanny, B.; Sansoni, A.; Santamarina Rios, C.; Santoni, C.; Santonico, R.; Saraiva, J. G.; Sarangi, T.; Sarkisyan-Grinbaum, E.; Sarri, F.; Sasaki, O.; Sasao, N.; Satsounkevitch, I.; Sauvage, G.; Savard, P.; Savine, A. Y.; Savinov, V.; Sawyer, L.; Saxon, D. H.; Says, L. P.; Sbarra, C.; Sbrizzi, A.; Scannicchio, D. A.; Schaarschmidt, J.; Schacht, P.; Schäfer, U.; Schaetzel, S.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Schamov, A. G.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schieck, J.; Schioppa, M.; Schlenker, S.; Schmieden, K.; Schmitt, C.; Schmitz, M.; Schott, M.; Schouten, D.; Schovancova, J.; Schram, M.; Schreiner, A.; Schroeder, C.; Schroer, N.; Schroers, M.; Schultes, J.; Schultz-Coulon, H.-C.; Schumacher, J. W.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwemling, Ph.; Schwienhorst, R.; Schwierz, R.; Schwindling, J.; Scott, W. G.; Searcy, J.; Sedykh, E.; Segura, E.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Seliverstov, D. M.; Sellden, B.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Seuster, R.; Severini, H.; Sevior, M. E.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shank, J. T.; Shao, Q. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Sherman, D.; Sherwood, P.; Shibata, A.; Shimojima, M.; Shin, T.; Shmeleva, A.; Shochet, M. J.; Shupe, M. A.; Sicho, P.; Sidoti, A.; Siegert, F.; Siegrist, J.; Sijacki, Dj.; Silbert, O.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S. B.; Simak, V.; Simic, Lj.; Simion, S.; Simmons, B.; Simonyan, M.; Sinervo, P.; Sinev, N. B.; Sipica, V.; Siragusa, G.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjoelin, J.; Sjursen, T. B.; Skovpen, K.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Sloper, J.; Sluka, T.; Smakhtin, V.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, B. C.; Smith, D.; Smith, K. M.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snow, S. W.; Snow, J.; Snuverink, J.; Snyder, S.; Soares, M.; Sobie, R.; Sodomka, J.; Soffer, A.; Solans, C. A.; Solar, M.; Solc, J.; Solfaroli Camillocci, E.; Solodkov, A. A.; Solovyanov, O. V.; Soluk, R.; Sondericker, J.; Sopko, V.; Sopko, B.; Sosebee, M.; Soukharev, A.; Spagnolo, S.; Spanò, F.; Spencer, E.; Spighi, R.; Spigo, G.; Spila, F.; Spiwoks, R.; Spousta, M.; Spreitzer, T.; Spurlock, B.; Denis, R. D. St.; Stahl, T.; Stahlman, J.; Stamen, R.; Stancu, S. N.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Stastny, J.; Stavina, P.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stevenson, K.; Stewart, G. A.; Stockton, M. C.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Strachota, P.; Stradling, A. R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Strube, J.; Stugu, B.; Soh, D. A.; Su, D.; Sugaya, Y.; Sugimoto, T.; Suhr, C.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, X. H.; Sundermann, J. E.; Suruliz, K.; Sushkov, S.; Susinno, G.; Sutton, M. R.; Suzuki, T.; Suzuki, Y.; Sykora, I.; Sykora, T.; Szymocha, T.; Sánchez, J.; Ta, D.; Tackmann, K.; Taffard, A.; Tafirout, R.; Taga, A.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Talby, M.; Talyshev, A.; Tamsett, M. C.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tapprogge, S.; Tardif, D.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tassi, E.; Tatarkhanov, M.; Taylor, C.; Taylor, F. E.; Taylor, G. N.; Taylor, R. P.; Taylor, W.; Teixeira-Dias, P.; Ten Kate, H.; Teng, P. K.; Tennenbaum-Katan, Y. D.; Terada, S.; Terashi, K.; Terron, J.; Terwort, M.; Testa, M.; Teuscher, R. J.; Thioye, M.; Thoma, S.; Thomas, J. P.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, R. J.; Thompson, A. S.; Thomson, E.; Thun, R. P.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Y. A.; Tipton, P.; Tique Aires Viegas, F. J.; Tisserant, S.; Toczek, B.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tomasek, L.; Tomasek, M.; Tomoto, M.; Tompkins, L.; Toms, K.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torrence, E.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Trinh, T. N.; Tripiana, M. F.; Triplett, N.; Trischuk, W.; Trivedi, A.; Trocmé, B.; Troncon, C.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiakiris, M.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tuggle, J. M.; Turecek, D.; Turk Cakir, I.; Turlay, E.; Tuts, P. M.; Twomey, M. S.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ugland, M.; Uhlenbrock, M.; Uhrmacher, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Unno, Y.; Urbaniec, D.; Urkovsky, E.; Urquijo, P.; Urrejola, P.; Usai, G.; Uslenghi, M.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valente, P.; Valentinetti, S.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; van Berg, R.; van der Graaf, H.; van der Kraaij, E.; van der Poel, E.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vari, R.; Varnes, E. W.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vasilyeva, L.; Vassilakopoulos, V. I.; Vazeille, F.; Vellidis, C.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Viehhauser, G. H. A.; Villa, M.; Villani, E. G.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinek, E.; Vinogradov, V. B.; Viret, S.; Virzi, J.; Vitale, A.; Vitells, O.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vlasak, M.; Vlasov, N.; Vogel, A.; Vokac, P.; Volpi, M.; von der Schmitt, H.; von Loeben, J.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorwerk, V.; Vos, M.; Voss, R.; Voss, T. T.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Anh, T. Vu; Vudragovic, D.; Vuillermet, R.; Vukotic, I.; Wagner, P.; Walbersloh, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Wang, C.; Wang, H.; Wang, J.; Wang, S. M.; Warburton, A.; Ward, C. P.; Warsinsky, M.; Wastie, R.; Watkins, P. M.; Watson, A. T.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, A. T.; Waugh, B. M.; Weber, M. D.; Weber, M.; Weber, M. S.; Weber, P.; Weidberg, A. R.; Weingarten, J.; Weiser, C.; Wellenstein, H.; Wells, P. S.; Wen, M.; Wenaus, T.; Wendler, S.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Werth, M.; Werthenbach, U.; Wessels, M.; Whalen, K.; White, A.; White, M. J.; White, S.; Whitehead, S. R.; Whiteson, D.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik, L. A. M.; Wildauer, A.; Wildt, M. A.; Wilkens, H. G.; Williams, E.; Williams, H. H.; Willocq, S.; Wilson, J. A.; Wilson, M. G.; Wilson, A.; Wingerter-Seez, I.; Winklmeier, F.; Wittgen, M.; Wolter, M. W.; Wolters, H.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wraight, K.; Wright, C.; Wright, D.; Wrona, B.; Wu, S. L.; Wu, X.; Wulf, E.; Wynne, B. M.; Xaplanteris, L.; Xella, S.; Xie, S.; Xu, D.; Xu, N.; Yamada, M.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamaoka, J.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, U. K.; Yang, Z.; Yao, W.-M.; Yao, Y.; Yasu, Y.; Ye, J.; Ye, S.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Young, C.; Youssef, S. P.; Yu, D.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zaidan, R.; Zaitsev, A. M.; Zajacova, Z.; Zambrano, V.; Zanello, L.; Zaytsev, A.; Zeitnitz, C.; Zeller, M.; Zemla, A.; Zendler, C.; Zenin, O.; Zenis, T.; Zenonos, Z.; Zenz, S.; Zerwas, D.; Della Porta, G. Zevi; Zhan, Z.; Zhang, H.; Zhang, J.; Zhang, Q.; Zhang, X.; Zhao, L.; Zhao, T.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, N.; Zhou, Y.; Zhu, C. G.; Zhu, H.; Zhu, Y.; Zhuang, X.; Zhuravlov, V.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; Zur Nedden, M.; Zutshi, V.

2010-12-01

The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions.

Tracking Servobridge Detector. Volume 1

DTIC Science & Technology

1976-12-15

34 _ - b[ Section 1 ABSTRACT 1.0 General This report is in three volumes - Volume I describes technically the Tracking Servo Bridge Detector in final...28 4.1.9.2 Typical Pulse Generator ....... ............... ... 29 4.1.10 Unlock Alarm .......... ..................... .... 30 4.1.11.1 DC...46 4.3.8.4 RF Oucput Harmonic Distortion vs. Frequency Plot . . .. 48 4.3.8.5 Generator Input Level Limits vs. Frequency Plot. . . .. 49 4.3.8.6 RF

Gamma-ray tracking method for pet systems

DOEpatents

Mihailescu, Lucian; Vetter, Kai M.

2010-06-08

Gamma-ray tracking methods for use with granular, position sensitive detectors identify the sequence of the interactions taking place in the detector and, hence, the position of the first interaction. The improved position resolution in finding the first interaction in the detection system determines a better definition of the direction of the gamma-ray photon, and hence, a superior source image resolution. A PET system using such a method will have increased efficiency and position resolution.

Cosmic ray positron research and silicon track detector development

NASA Technical Reports Server (NTRS)

Jones, W. Vernon; Wefel, John P.

1991-01-01

The purpose was to conduct research on: (1) position sensing detector systems, particularly those based upon silicon detectors, for use in future balloon and satellite experiments; and (2) positrons, electrons, proton, anti-protons, and helium particles as measured by the NASA NMSU Balloon Magnet Facility.

The Silicon Tracking System of the CBM experiment at FAIR

NASA Astrophysics Data System (ADS)

Teklishyn, Maksym

2018-03-01

The Silicon Tracking System (STS) is the central detector in the Compressed Baryonic Matter (CBM) experiment at FAIR. Operating in the 1Tm dipole magnetic field, the STS will enable pile-up free detection and momentum measurement of the charged particles originating from beam-target nuclear interactions at rates up to 10 MHz. The STS consists of 8 tracking stations based on double-sided silicon micro-strip sensors equipped with fast, self-triggering read-out electronics. With about two million read-out channels, the STS will deliver a high-rate stream of time-stamped data that is transferred to a computing farm for on-line event determination and analysis. The functional building block is a detector module consisting of a sensor, micro-cables and two front-end electronics boards. In this contribution, the development status of the STS components and the system integration is discussed and an outlook on the detector construction is given.

Status of the evidence for a magnetic monopole

NASA Technical Reports Server (NTRS)

Price, P. B.

1975-01-01

The experimental evidence supporting the detection of a moving magnetic monopole, using a balloon-borne array of track detectors, was presented. Although the results cannot be proved to have been produced by a monopole, they do not seem to have been produced by any nucleus. The very high, roughly constant ionization rate inferred from track etch rate measurements in a stack of Lexan detectors implies passage of a minimum-ionizing particle more highly charged than any known nucleus, yet the Cerenkov film detectors indicated a velocity less than about 0.68 times the speed of light and the size of the track in the nuclear emulsion indicated a velocity approximately equal to 0.5 times the speed of light. At this velocity the ionization rate of a highly electrically charged particle would have changed dramatically with pathlength unless its mass to charge ratio were far greater than that of a nucleus.

On analyzing colour constancy approach for improving SURF detector performance

NASA Astrophysics Data System (ADS)

Zulkiey, Mohd Asyraf; Zaki, Wan Mimi Diyana Wan; Hussain, Aini; Mustafa, Mohd. Marzuki

2012-04-01

Robust key point detector plays a crucial role in obtaining a good tracking feature. The main challenge in outdoor tracking is the illumination change due to various reasons such as weather fluctuation and occlusion. This paper approaches the illumination change problem by transforming the input image through colour constancy algorithm before applying the SURF detector. Masked grey world approach is chosen because of its ability to perform well under local as well as global illumination change. Every image is transformed to imitate the canonical illuminant and Gaussian distribution is used to model the global change. The simulation results show that the average number of detected key points have increased by 69.92%. Moreover, the average of improved performance cases far out weight the degradation case where the former is improved by 215.23%. The approach is suitable for tracking implementation where sudden illumination occurs frequently and robust key point detection is needed.

A precision device needs precise simulation: Software description of the CBM Silicon Tracking System

NASA Astrophysics Data System (ADS)

Malygina, Hanna; Friese, Volker; CBM Collaboration

2017-10-01

Precise modelling of detectors in simulations is the key to the understanding of their performance, which, in turn, is a prerequisite for the proper design choice and, later, for the achievement of valid physics results. In this report, we describe the implementation of the Silicon Tracking System (STS), the main tracking device of the CBM experiment, in the CBM software environment. The STS makes uses of double-sided silicon micro-strip sensors with double metal layers. We present a description of transport and detector response simulation, including all relevant physical effects like charge creation and drift, charge collection, cross-talk and digitization. Of particular importance and novelty is the description of the time behaviour of the detector, since its readout will not be externally triggered but continuous. We also cover some aspects of local reconstruction, which in the CBM case has to be performed in real-time and thus requires high-speed algorithms.

Immunogenicity and immunoprotection of porcine circovirus type 2 (PCV2) Cap protein displayed by Lactococcus lactis.

PubMed

Li, Peng-Cheng; Qiao, Xu-Wen; Zheng, Qi-Sheng; Hou, Ji-Bo

2016-01-27

The capsid (Cap) protein, an important immunoprotective protein of porcine circovirus type 2 (PCV2), was expressed on the cell surface of the Gram-positive food-grade bacterium, Lactococcus lactis. Cap protein was fused to the peptidoglycan binding domain (known as the protein anchor domain, PA) of the lactococcal AcmA cell-wall hydrolase. The Cap protein fusion was non-covalently rebound to the surface of non-genetically modified, non-living high-binder L. lactis cells (designated Gram-positive enhancer matrix (GEM) particles). Expression of the recombinant GEM-displaying capsid protein (GEM-PA-Cap) was verified by Western blotting and immunofluorescence and transmission electron microscopy assays. To evaluate the immunogenicity of the recombinant Cap protein (rCap), 20 PCV2-seronegative piglets were immunized with the GEM-PA-Cap subunit vaccine, GEM alone, or phosphate-buffered saline (PBS, challenge control and empty control). Each group consisted of five piglets. The results showed that the level of PCV2-specific antibodies in piglets immunized with the GEM-PA-Cap subunit vaccine was significantly higher than that of the piglets immunized with GEM alone or the control group at all the time points post-vaccination (P<0.01). After challenge with the PCV2 wild-type strain, piglets that received the GEM-PA-Cap subunit vaccine showed significantly higher average daily weight gain (DWG) and shorter fever duration than the other two groups (P<0.001). Furthermore, a significant reduction in the gross lung lesion scores and lymph node lesion scores was noted in the GEM-PA-Cap-immunized group compared with the scores of the GEM or PBS-treated group (P<0.01). The results suggest that recombinant rCap displayed by L. lactis GEM particles provided the piglets with significant immunoprotection from PCV2-associated disease. Thus, the novel GEM-PA-Cap subunit vaccine has potential to be considered an effective and safe candidate vaccine against PCV2 infection in piglets. Copyright © 2015. Published by Elsevier Ltd.

Emissions of mercury in Southern Africa derived from long-term observations at Cape Point, South Africa

NASA Astrophysics Data System (ADS)

Brunke, E.-G.; Ebinghaus, R.; Kock, H. H.; Labuschagne, C.; Slemr, F.

2012-05-01

Mercury emissions in South Africa have so far been estimated only by a bottom-up approach from activities and emission factors for different processes. In this paper we derive GEM/CO (GEM being gaseous elemental mercury, Hg0), GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios from plumes observed during long-term monitoring of these species at Cape Point between March 2007 and December 2009. The average observed GEM/CO, GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios were 2.40 ± 2.65 pg m-3 ppb-1 (n = 47), 62.7 ± 80.2 pg m-3 ppb-1 (n = 44), 3.61 ± 4.66 pg m-3 ppb-1 (n = 46), 35.6 ± 25.4 ppb ppm-1 (n = 52), 20.2 ± 15.5 ppb ppm-1 (n=48), and 0.876 ± 1.106 ppb ppm-1 (n=42), respectively. The observed CO/CO2, CH4/CO2, and CH4/CO emission ratios agree within the combined uncertainties of the observations and emissions with the ratios calculated from EDGAR (version 4.2) CO2, CO, and CH4 inventories for South Africa and Southern Africa (South Africa, Lesotho, Swaziland, Namibia, Botswana, Zimbabwe, and Mozambique) in 2007 and 2008 (inventories for 2009 are not available yet). Total elemental mercury emission of 13.1, 15.2, and 16.1 t Hg yr-1 are estimated independently using the GEM/CO, GEM/CO2, and GEM/CH4 emission ratios and the annual mean CO, CO2, and CH4 emissions, respectively, of South Africa in 2007 and 2008. The average of these independent estimates of 14.8 ± 1.5 t GEM yr-1 is much less than the total emission of 257 t Hg yr-1 from older inventories. Considering that emission of GEM represents only 50-78% of all mercury emissions, our estimates come close to the total mercury emission estimates ranging between 40-50 t Hg yr-1 from more recent inventories.

Track reconstruction and particle identification developments for a study of event-by-event fluctuations in heavy ion collisions at NICA

NASA Astrophysics Data System (ADS)

Mudrokh, A. A.; Zinchenko, A. I.

2017-01-01

A Monte Carlo simulation of heavy ion collisions (Au+Au) has been performed at MPD (Multi Purpose Detector) at NICA (Dubna) for a study of the possible critical point in the phase diagram of the hot nuclear matter. The simulation took into account real detector effects with as many details as possible to properly describe the apparatus response. Particle identification (PID) has been tuned to account for modifications in track reconstruction. Some results on hadron identification in the TPC and TOF (Time Of Flight) detectors with realistically simulated response have been also obtained.

Commissioning of the ATLAS pixel detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

ATLAS Collaboration; Golling, Tobias

2008-09-01

The ATLAS pixel detector is a high precision silicon tracking device located closest to the LHC interaction point. It belongs to the first generation of its kind in a hadron collider experiment. It will provide crucial pattern recognition information and will largely determine the ability of ATLAS to precisely track particle trajectories and find secondary vertices. It was the last detector to be installed in ATLAS in June 2007, has been fully connected and tested in-situ during spring and summer 2008, and is ready for the imminent LHC turn-on. The highlights of the past and future commissioning activities of themore » ATLAS pixel system are presented.« less

Extending the ISC-GEM Global Earthquake Instrumental Catalogue

NASA Astrophysics Data System (ADS)

Di Giacomo, Domenico; Engdhal, Bob; Storchak, Dmitry; Villaseñor, Antonio; Harris, James

2015-04-01

After a 27-month project funded by the GEM Foundation (www.globalquakemodel.org), in January 2013 we released the ISC-GEM Global Instrumental Earthquake Catalogue (1900 2009) (www.isc.ac.uk/iscgem/index.php) as a special product to use for seismic hazard studies. The new catalogue was necessary as improved seismic hazard studies necessitate that earthquake catalogues are homogeneous (to the largest extent possible) over time in their fundamental parameters, such as location and magnitude. Due to time and resource limitation, the ISC-GEM catalogue (1900-2009) included earthquakes selected according to the following time-variable cut-off magnitudes: Ms=7.5 for earthquakes occurring before 1918; Ms=6.25 between 1918 and 1963; and Ms=5.5 from 1964 onwards. Because of the importance of having a reliable seismic input for seismic hazard studies, funding from GEM and two commercial companies in the US and UK allowed us to start working on the extension of the ISC-GEM catalogue both for earthquakes that occurred beyond 2009 and for earthquakes listed in the International Seismological Summary (ISS) which fell below the cut-off magnitude of 6.25. This extension is part of a four-year program that aims at including in the ISC-GEM catalogue large global earthquakes that occurred before the beginning of the ISC Bulletin in 1964. In this contribution we present the updated ISC GEM catalogue, which will include over 1000 more earthquakes that occurred in 2010 2011 and several hundreds more between 1950 and 1959. The catalogue extension between 1935 and 1949 is currently underway. The extension of the ISC-GEM catalogue will also be helpful for regional cross border seismic hazard studies as the ISC-GEM catalogue should be used as basis for cross-checking the consistency in location and magnitude of those earthquakes listed both in the ISC GEM global catalogue and regional catalogues.

Temporal distribution and potential sources of atmospheric mercury measured at a high-elevation background station in Taiwan

NASA Astrophysics Data System (ADS)

Sheu, Guey-Rong; Lin, Neng-Huei; Wang, Jia-Lin; Lee, Chung-Te; Ou Yang, Chang-Feng; Wang, Sheng-Hsiang

2010-07-01

Measurements of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate mercury (PHg) have been conducted at Lulin Atmospheric Background Station (LABS) in Taiwan since April 2006. This was the first long-term free tropospheric atmospheric Hg monitoring program in the downwind region of East Asia, which is a major Hg emission source region. Between April 13, 2006 and December 31, 2007, the mean concentrations of GEM, RGM, and PHg were 1.73 ng m -3, 12.1 pg m -3, and 2.3 pg m -3, respectively. A diurnal pattern was observed for GEM with afternoon peaks and nighttime lows, whereas the diurnal pattern of RGM was opposite to that of GEM. Spikes of RGM were frequently observed between midnight and early morning with concurrent decreases in GEM and relative humidity and increases in O 3, suggesting the oxidation of GEM and formation of RGM in free troposphere (FT). Upslope movement of boundary layer (BL) air in daytime and subsidence of FT air at night resulted in these diurnal patterns. Considering only the nighttime data, which were more representative of FT air, the composite monthly mean GEM concentrations ranged between 1.06 and 2.06 ng m -3. Seasonal variation in nighttime GEM was evident, with lower concentrations usually occurring in summer when clean marine air masses prevailed. Between fall and spring, air masses passed the East Asian continent prior to reaching LABS, contributing to the elevated GEM concentrations. Analysis of GEM/CO correlation tends to support the argument. Good GEM/CO correlations were observed in fall, winter, and spring, suggesting influence of anthropogenic emission sources. Our results demonstrate the significance of East Asian Hg emissions, including both anthropogenic and biomass burning emissions, and their long-range transport in the FT. Because of the pronounced seasonal monsoon activity and the seasonal variation in regional wind field, export of the Asian Hg emissions to Taiwan occurs mainly during fall, winter, and spring.

Impaired clinical utility of sequential patient GEM blood gas measurements associated with calibration schedule.

PubMed

Cembrowski, George S; Xu, Qian; Cembrowski, Adam R; Mei, Junyi; Sadrzadeh, Hossein

2017-11-01

Within- and/or between-instrument variation may falsely indicate patient trends or obscure real trends. We employ a methodology that transforms sequential intra-patient results into estimates of biologic and analytic variation. We previously derived realistic biologic variation (s b ) of blood gas (BG) and hematology analytes. We extend this methodology to derive the imprecision of two GEM 4000 BG analyzers. A laboratory data repository provided arterial BG, electrolyte and metabolite results generated by two GEM 4000s on ICU patients in 2012-2013. We tabulated consecutive pairs of intra-patient results separated by increasing time interval between consecutive tests. The average between pair variations were regressed against time with the y-intercept representing the sum of the biologic variation and short term analytic variation: y o 2 =s b 2 +s a 2 . Using an equivalent equation for the Radiometer ABL, the imprecision of the two GEMs was calculated: s aGEM =(y oGEM 2 -y oABL 2 +s aABL 2 ) 1/2 . This analysis was performed for nearly all measurements, regardless of time as well for values obtained over two 12h mutually exclusive periods, starting either at 2am or 2pm. Regression graphs were derived from 1800 patients' blood gas results with least 10,000 data pairs grouped into 2h intervals. The calculated s aGEM exceed the directly measured s aABL with many GEM sigma ratios of biologic variation/analytic variation being close to unity. All of the afternoon s aGEM exceeded their morning counterparts with pH, pCO 2 , K and bicarbonate being statistically significant. For many analytes, the average analytical variation of tandem GEMs approximates the biologic variation, indicating impaired clinical usefulness of tandem sequential measurements. A significant component of this variation is due to increased variation of the GEMs between 2pm and 2am. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

ATLAS FTK a - very complex - custom super computer

NASA Astrophysics Data System (ADS)

Kimura, N.; ATLAS Collaboration

2016-10-01

In the LHC environment for high interaction pile-up, advanced techniques of analysing the data in real time are required in order to maximize the rate of physics processes of interest with respect to background processes. The Fast TracKer (FTK) is a track finding implementation at the hardware level that is designed to deliver full-scan tracks with pT above 1 GeV to the ATLAS trigger system for events passing the Level-1 accept (at a maximum rate of 100 kHz). In order to achieve this performance, a highly parallel system was designed and currently it is being commissioned within in ATLAS. Starting in 2016 it will provide tracks for the trigger system in a region covering the central part of the ATLAS detector, and will be extended to the full detector coverage. The system relies on matching hits coming from the silicon tracking detectors against one billion patterns stored in custom ASIC chips (Associative memory chip - AM06). In a first stage, coarse resolution hits are matched against the patterns and the accepted hits undergo track fitting implemented in FPGAs. Tracks with pT > 1GeV are delivered to the High Level Trigger within about 100 ps. Resolution of the tracks coming from FTK is close to the offline tracking and it will allow for reliable detection of primary and secondary vertexes at trigger level and improved trigger performance for b-jets and tau leptons. This contribution will give an overview of the FTK system and present the status of commissioning of the system. Additionally, the expected FTK performance will be briefly described.

Performance of a Quintuple-GEM Based RICHDetector Prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blatnik, Marie; Dehmelt, Klaus; Deshpande, Abhay

2015-12-17

Cerenkov technology is often the optimal choice for particle identification in high energy particle collision applications. Typically, the most challenging regime is at high pseudorapidity (forward) where particle identification must perform well at high laboratory momenta. For the upcoming electron ion collider (EIC), the physics goals require hadron (π, K, p) identification up to ~50 GeV/c. In this region Cerenkov ring-imaging (RICH) is the most viable solution. The speed of light in a radiator medium is inversely proportional to the refractive index. Hence, for particle identification (PID) reaching out to high momenta a small index of refraction is required. Unfortunately,more » the lowest indices of refraction also result in the lowest light yield ([(dNγ)/dx] ∝ sin2(θC)) driving up the radiator length and thereby the overall detector cost. In this paper we report on a successful test of a compact RICH detector (1 meter radiator) capable of delivering in excess of 10 photoelectrons per ring with a low index radiator gas (CF4). The detector concept is a natural extension of the PHENIX hadron-blind detector (HBD) achieved by adding focusing capability at low wavelength and adequate gain for high efficiency detection of single-electron induced avalanches. Our results indicate that this technology is indeed a viable choice in the forward direction of the EIC. The setup and results are described within.« less

Applications of Gas Imaging Micro-Well Detectors to an Advanced Compton Telescope

NASA Technical Reports Server (NTRS)

Bloser, P. F.; Hunter, S. D.; Ryan, J. M.; McConnell, M. L.; Miller, R. S.; Jackson, T. N.; Bai, B.; Jung, S.

2003-01-01

We present a concept for an Advanced Compton Telescope (ACT) based on the use of pixelized gas micro-well detectors to form a three-dimensional electron track imager. A micro-well detector consists of an array of individual micro-patterned proportional counters opposite a planar drift electrode. When combined with thin film transistor array readouts, large gas volumes may be imaged with very good spatial and energy resolution at reasonable cost. The third dimension is determined by timing the drift of the ionization electrons. The primary advantage of this approach is the excellent tracking of the Compton recoil electron that is possible in a gas volume. Such good electron tracking allows us to reduce the point spread function of a single incident photon dramatically, greatly improving the imaging capability and sensitivity. The polarization sensitivity, which relies on events with large Compton scattering angles, is particularly enhanced. We describe a possible ACT implementation of this technique, in which the gas tracking volume is surrounded by a CsI calorimeter, and present our plans to build and test a small prototype over the next three years.

Investigation of CMOS pixel sensor with 0.18 μm CMOS technology for high-precision tracking detector

NASA Astrophysics Data System (ADS)

Zhang, L.; Fu, M.; Zhang, Y.; Yan, W.; Wang, M.

2017-01-01

The Circular Electron Positron Collider (CEPC) proposed by the Chinese high energy physics community is aiming to measure Higgs particles and their interactions precisely. The tracking detector including Silicon Inner Tracker (SIT) and Forward Tracking Disks (FTD) has driven stringent requirements on sensor technologies in term of spatial resolution, power consumption and readout speed. CMOS Pixel Sensor (CPS) is a promising candidate to approach these requirements. This paper presents the preliminary studies on the sensor optimization for tracking detector to achieve high collection efficiency while keeping necessary spatial resolution. Detailed studies have been performed on the charge collection using a 0.18 μm CMOS image sensor process. This process allows high resistivity epitaxial layer, leading to a significant improvement on the charge collection and therefore improving the radiation tolerance. Together with the simulation results, the first exploratory prototype has bee designed and fabricated. The prototype includes 9 different pixel arrays, which vary in terms of pixel pitch, diode size and geometry. The total area of the prototype amounts to 2 × 7.88 mm2.

Dynamic sea surface topography, gravity and improved orbit accuracies from the direct evaluation of SEASAT altimeter data

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Lerch, F.; Koblinsky, C. J.; Klosko, S. M.; Robbins, J. W.; Williamson, R. G.; Patel, G. B.

1989-01-01

A method for the simultaneous solution of dynamic ocean topography, gravity and orbits using satellite altimeter data is described. A GEM-T1 based gravitational model called PGS-3337 that incorporates Seasat altimetry, surface gravimetry and satellite tracking data has been determined complete to degree and order 50. The altimeter data is utilized as a dynamic observation of the satellite's height above the sea surface with a degree 10 model of dynamic topography being recovered simultaneously with the orbit parameters, gravity and tidal terms in this model. PGS-3337 has a geoid uncertainty of 60 cm root-mean-square (RMS) globally, with the uncertainty over the altimeter tracked ocean being in the 25 cm range. Doppler determined orbits for Seasat, show large improvements, with the sub-30 cm radial accuracies being achieved. When altimeter data is used in orbit determination, radial orbital accuracies of 20 cm are achieved. The RMS of fit to the altimeter data directly gives 30 cm fits for Seasat when using PGS-3337 and its geoid and dynamic topography model. This performance level is two to three times better than that achieved with earlier Goddard earth models (GEM) using the dynamic topography from long-term oceanographic averages. The recovered dynamic topography reveals the global long wavelength circulation of the oceans with a resolution of 1500 km. The power in the dynamic topography recovery is now found to be closer to that of oceanographic studies than for previous satellite solutions. This is attributed primarily to the improved modeling of the geoid which has occurred. Study of the altimeter residuals reveals regions where tidal models are poor and sea state effects are major limitations.

Photodegradation of gemfibrozil in aqueous solution under UV irradiation: kinetics, mechanism, toxicity, and degradation pathways.

PubMed

Ma, Jingshuai; Lv, Wenying; Chen, Ping; Lu, Yida; Wang, Fengliang; Li, Fuhua; Yao, Kun; Liu, Guoguang

2016-07-01

The lipid regulator gemfibrozil (GEM) has been reported to be persistent in conventional wastewater treatment plants. This study investigated the photolytic behavior, toxicity of intermediate products, and degradation pathways of GEM in aqueous solutions under UV irradiation. The results demonstrated that the photodegradation of GEM followed pseudo-first-order kinetics, and the pseudo-first-order rate constant was decreased markedly with increasing initial concentrations of GEM and initial pH. The photodegradation of GEM included direct photolysis via (3)GEM(*) and self-sensitization via ROS, where the contribution rates of degradation were 0.52, 90.05, and 8.38 % for ·OH, (1)O2, and (3)GEM(*), respectively. Singlet oxygen ((1)O2) was evidenced by the molecular probe compound, furfuryl alcohol (FFA), and was identified as the primary reactive species in the photolytic process. The steady-state concentrations of (1)O2 increased from (0.324 ± 0.014) × 10(-12) to (1.021 ± 0.040) × 10(-12) mol L(-1), as the initial concentrations of GEM were increased from 5 to 20 mg L(-1). The second-order rate constant for the reaction of GEM with (1)O2 was calculated to be 2.55 × 10(6) M(-1) s(-1). The primary transformation products were identified using HPLC-MS/MS, and possible photodegradation pathways were proposed by hydroxylation, aldehydes reactions, as well as the cleavage of ether side chains. The toxicity of phototransformation product evaluation revealed that photolysis potentially provides a critical pathway for GEM toxicity reduction in potable water and wastewater treatment facilities.

Study of the material of the ATLAS inner detector for Run 2 of the LHC

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2017-12-07

The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity √s=13 TeV pp collision sample corresponding to around 2.0 nb -1 collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studiedmore » using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation.« less

Study of the material of the ATLAS inner detector for Run 2 of the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaboud, M.; Aad, G.; Abbott, B.

The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity √s=13 TeV pp collision sample corresponding to around 2.0 nb -1 collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studiedmore » using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation.« less

Study of the material of the ATLAS inner detector for Run 2 of the LHC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaboud, M.; Aad, G.; Abbott, B.

The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity √s = 13 TeV pp collision sample corresponding to around 2.0 nb -1 collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel regionmore » is studied using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation.« less

Study of the material of the ATLAS inner detector for Run 2 of the LHC

NASA Astrophysics Data System (ADS)

Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S. H.; AbouZeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adachi, S.; Adamczyk, L.; Adelman, J.; Adersberger, M.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agheorghiesei, C.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akatsuka, S.; Akerstedt, H.; Åkesson, T. P. A.; Akilli, E.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albicocco, P.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Ali, B.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Alshehri, A. A.; Alstaty, M.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Angerami, A.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antel, C.; Antonelli, M.; Antonov, A.; Antrim, D. J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Araujo Ferraz, V.; Arce, A. T. H.; Ardell, R. E.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Armitage, L. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Artz, S.; Asai, S.; Asbah, N.; Ashkenazi, A.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baas, A. E.; Baca, M. J.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagnaia, P.; Bahrasemani, H.; Baines, J. T.; Bajic, M.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balli, F.; Balunas, W. K.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisits, M.-S.; Barkeloo, J. T.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska-Blenessy, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barranco Navarro, L.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bedognetti, M.; Bee, C. P.; Beermann, T. A.; Begalli, M.; Begel, M.; Behr, J. K.; Bell, A. S.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Belyaev, N. L.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez, J.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Beringer, J.; Berlendis, S.; Bernard, N. R.; Bernardi, G.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertram, I. A.; Bertsche, C.; Bertsche, D.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethani, A.; Bethke, S.; Bevan, A. J.; Beyer, J.; Bianchi, R. M.; Biebel, O.; Biedermann, D.; Bielski, R.; Biesuz, N. V.; Biglietti, M.; Bilbao De Mendizabal, J.; Billoud, T. R. V.; Bilokon, H.; Bindi, M.; Bingul, A.; Bini, C.; Biondi, S.; Bisanz, T.; Bittrich, C.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blair, R. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blue, A.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Boerner, D.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bokan, P.; Bold, T.; Boldyrev, A. S.; Bolz, A. E.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Bortfeldt, J.; Bortoletto, D.; Bortolotto, V.; Boscherini, D.; Bosman, M.; Bossio Sola, J. D.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Breaden Madden, W. D.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Briglin, D. L.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Broughton, J. H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruni, A.; Bruni, G.; Bruni, L. S.; Brunt, BH; Bruschi, M.; Bruscino, N.; Bryant, P.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Budagov, I. A.; Buehrer, F.; Bugge, M. K.; Bulekov, O.; Bullock, D.; Burch, T. J.; Burckhart, H.; Burdin, S.; Burgard, C. D.; Burger, A. M.; Burghgrave, B.; Burka, K.; Burke, S.; Burmeister, I.; Burr, J. T. P.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Buzykaev, A. R.; Cabrera Urbán, S.; Caforio, D.; Cairo, V. M.; Cakir, O.; Calace, N.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Callea, G.; Caloba, L. P.; Calvente Lopez, S.; Calvet, D.; Calvet, S.; Calvet, T. P.; Camacho Toro, R.; Camarda, S.; Camarri, P.; Cameron, D.; Caminal Armadans, R.; Camincher, C.; Campana, S.; Campanelli, M.; Camplani, A.; Campoverde, A.; Canale, V.; Cano Bret, M.; Cantero, J.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Carbone, R. M.; Cardarelli, R.; Cardillo, F.; Carli, I.; Carli, T.; Carlino, G.; Carlson, B. T.; Carminati, L.; Carney, R. M. D.; Caron, S.; Carquin, E.; Carrá, S.; Carrillo-Montoya, G. D.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Casper, D. W.; Castelijn, R.; Castillo Gimenez, V.; Castro, N. F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caudron, J.; Cavaliere, V.; Cavallaro, E.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Celebi, E.; Ceradini, F.; Cerda Alberich, L.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chan, S. K.; Chan, W. S.; Chan, Y. L.; Chang, P.; Chapman, J. D.; Charlton, D. G.; Chau, C. C.; Chavez Barajas, C. A.; Che, S.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, S.; Chen, S.; Chen, X.; Chen, Y.; Cheng, H. C.; Cheng, H. J.; Cheplakov, A.; Cheremushkina, E.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Cheung, K.; Chevalier, L.; Chiarella, V.; Chiarelli, G.; Chiodini, G.; Chisholm, A. S.; Chitan, A.; Chiu, Y. H.; Chizhov, M. V.; Choi, K.; Chomont, A. R.; Chouridou, S.; Christodoulou, V.; Chromek-Burckhart, D.; Chu, M. C.; Chudoba, J.; Chuinard, A. J.; Chwastowski, J. J.; Chytka, L.; Ciftci, A. K.; Cinca, D.; Cindro, V.; Cioara, I. A.; Ciocca, C.; Ciocio, A.; Cirotto, F.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, B. L.; Clark, M. R.; Clark, P. J.; Clarke, R. N.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Colasurdo, L.; Cole, B.; Colijn, A. P.; Collot, J.; Colombo, T.; Conde Muiño, P.; Coniavitis, E.; Connell, S. H.; Connelly, I. A.; Constantinescu, S.; Conti, G.; Conventi, F.; Cooke, M.; Cooper-Sarkar, A. M.; Cormier, F.; Cormier, K. J. R.; Corradi, M.; Corriveau, F.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Crawley, S. J.; Creager, R. A.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. A.; Cristinziani, M.; Croft, V.; Crosetti, G.; Cueto, A.; Cuhadar Donszelmann, T.; Cukierman, A. R.; Cummings, J.; Curatolo, M.; Cúth, J.; Czirr, H.; Czodrowski, P.; D'amen, G.; D'Auria, S.; D'eramo, L.; D'Onofrio, M.; Da Cunha Sargedas De Sousa, M. J.; Da Via, C.; Dabrowski, W.; Dado, T.; Dai, T.; Dale, O.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Dandoy, J. R.; Daneri, M. F.; Dang, N. P.; Daniells, A. C.; Dann, N. S.; Danninger, M.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darmora, S.; Dassoulas, J.; Dattagupta, A.; Daubney, T.; Davey, W.; David, C.; Davidek, T.; Davies, M.; Davis, D. R.; Davison, P.; Dawe, E.; Dawson, I.; De, K.; de Asmundis, R.; De Benedetti, A.; De Castro, S.; De Cecco, S.; De Groot, N.; de Jong, P.; De la Torre, H.; De Lorenzi, F.; De Maria, A.; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vasconcelos Corga, K.; De Vivie De Regie, J. B.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dedovich, D. V.; Dehghanian, N.; Deigaard, I.; Del Gaudio, M.; Del Peso, J.; Del Prete, T.; Delgove, D.; Deliot, F.; Delitzsch, C. M.; Dell'Acqua, A.; Dell'Asta, L.; Dell'Orso, M.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delporte, C.; Delsart, P. A.; DeMarco, D. A.; Demers, S.; Demichev, M.; Demilly, A.; Denisov, S. P.; Denysiuk, D.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deterre, C.; Dette, K.; Devesa, M. R.; Deviveiros, P. O.; Dewhurst, A.; Dhaliwal, S.; Di Bello, F. A.; Di Ciaccio, A.; Di Ciaccio, L.; Di Clemente, W. 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G.; McClymont, L. I.; McDonald, E. F.; Mcfayden, J. A.; Mchedlidze, G.; McMahon, S. J.; McNamara, P. C.; McPherson, R. A.; Meehan, S.; Megy, T. J.; Mehlhase, S.; Mehta, A.; Meideck, T.; Meier, K.; Meirose, B.; Melini, D.; Mellado Garcia, B. R.; Mellenthin, J. D.; Melo, M.; Meloni, F.; Menary, S. B.; Meng, L.; Meng, X. T.; Mengarelli, A.; Menke, S.; Meoni, E.; Mergelmeyer, S.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Theenhausen, H. Meyer Zu; Miano, F.; Middleton, R. P.; Miglioranzi, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Milesi, M.; Milic, A.; Miller, D. W.; Mills, C.; Milov, A.; Milstead, D. A.; Minaenko, A. A.; Minami, Y.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Minegishi, Y.; Ming, Y.; Mir, L. M.; Mistry, K. P.; Mitani, T.; Mitrevski, J.; Mitsou, V. A.; Miucci, A.; Miyagawa, P. S.; Mizukami, A.; Mjörnmark, J. 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C.; Ohman, H.; Oide, H.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Oleiro Seabra, L. F.; Olivares Pino, S. A.; Oliveira Damazio, D.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onogi, K.; Onyisi, P. U. E.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Orr, R. S.; Osculati, B.; Ospanov, R.; Garzon, G. Otero y.; Otono, H.; Ouchrif, M.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Owen, M.; Owen, R. E.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Pacheco Rodriguez, L.; Padilla Aranda, C.; Pagan Griso, S.; Paganini, M.; Paige, F.; Palacino, G.; Palazzo, S.; Palestini, S.; Palka, M.; Pallin, D.; Panagiotopoulou, E. St.; Panagoulias, I.; Pandini, C. E.; Panduro Vazquez, J. G.; Pani, P.; Panitkin, S.; Pantea, D.; Paolozzi, L.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, A. J.; Parker, M. A.; Parker, K. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pascuzzi, V. R.; Pasner, J. 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S.; Polychronakos, V.; Pommès, K.; Ponomarenko, D.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Poppleton, A.; Pospisil, S.; Potamianos, K.; Potrap, I. N.; Potter, C. J.; Poulard, G.; Poulsen, T.; Poveda, J.; Pozo Astigarraga, M. E.; Pralavorio, P.; Pranko, A.; Prell, S.; Price, D.; Price, L. E.; Primavera, M.; Prince, S.; Proklova, N.; Prokofiev, K.; Prokoshin, F.; Protopopescu, S.; Proudfoot, J.; Przybycien, M.; Puri, A.; Puzo, P.; Qian, J.; Qin, G.; Qin, Y.; Quadt, A.; Queitsch-Maitland, M.; Quilty, D.; Raddum, S.; Radeka, V.; Radescu, V.; Radhakrishnan, S. K.; Radloff, P.; Rados, P.; Ragusa, F.; Rahal, G.; Raine, J. A.; Rajagopalan, S.; Rangel-Smith, C.; Rashid, T.; Raspopov, S.; Ratti, M. G.; Rauch, D. M.; Rauscher, F.; Rave, S.; Ravinovich, I.; Rawling, J. H.; Raymond, M.; Read, A. L.; Readioff, N. P.; Reale, M.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reed, R. 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A.; Schweiger, H.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Sciandra, A.; Sciolla, G.; Scuri, F.; Scutti, F.; Searcy, J.; Seema, P.; Seidel, S. C.; Seiden, A.; Seixas, J. M.; Sekhniaidze, G.; Sekhon, K.; Sekula, S. J.; Semprini-Cesari, N.; Senkin, S.; Serfon, C.; Serin, L.; Serkin, L.; Sessa, M.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shaikh, N. W.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shaw, S. M.; Shcherbakova, A.; Shehu, C. Y.; Shen, Y.; Sherafati, N.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shipsey, I. P. J.; Shirabe, S.; Shiyakova, M.; Shlomi, J.; Shmeleva, A.; Shoaleh Saadi, D.; Shochet, M. J.; Shojaii, S.; Shope, D. R.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Sicho, P.; Sickles, A. M.; Sidebo, P. E.; Sideras Haddad, E.; Sidiropoulou, O.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silverstein, S. 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J.; Trefzger, T.; Tresoldi, F.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Trofymov, A.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; Truong, L.; Trzebinski, M.; Trzupek, A.; Tsang, K. W.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsui, K. M.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tu, Y.; Tudorache, A.; Tudorache, V.; Tulbure, T. T.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turgeman, D.; Turk Cakir, I.; Turra, R.; Tuts, P. M.; Ucchielli, G.; Ueda, I.; Ughetto, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urban, J.; Urquijo, P.; Urrejola, P.; Usai, G.; Usui, J.; Vacavant, L.; Vacek, V.; Vachon, B.; Vaidya, A.; Valderanis, C.; Valdes Santurio, E.; Valentinetti, S.; Valero, A.; Valéry, L.; Valkar, S.; Vallier, A.; Valls Ferrer, J. 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H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Wagner, P.; Wagner, W.; Wagner-Kuhr, J.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wallangen, V.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, Q.; Wang, R.; Wang, S. M.; Wang, T.; Wang, W.; Wang, W.; Wang, Z.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Washbrook, A.; Watkins, P. M.; Watson, A. T.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, A. F.; Webb, S.; Weber, M. S.; Weber, S. W.; Weber, S. A.; Webster, J. S.; Weidberg, A. R.; Weinert, B.; Weingarten, J.; Weirich, M.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M. D.; Werner, P.; Wessels, M.; Whalen, K.; Whallon, N. L.; Wharton, A. M.; White, A. S.; White, A.; White, M. J.; White, R.; Whiteson, D.; Whitmore, B. W.; Wickens, F. 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M.; Zakharchuk, N.; Zalieckas, J.; Zaman, A.; Zambito, S.; Zanzi, D.; Zeitnitz, C.; Zemaityte, G.; Zemla, A.; Zeng, J. C.; Zeng, Q.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, L.; Zhang, M.; Zhang, P.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Y.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, M.; Zhou, M.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; Zou, R.; zur Nedden, M.; Zwalinski, L.

2017-12-01

The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity √s=13 TeV pp collision sample corresponding to around 2.0 nb-1 collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel region is studied using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation.

Study of the material of the ATLAS inner detector for Run 2 of the LHC

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2017-12-07

The ATLAS inner detector comprises three different sub-detectors: the pixel detector, the silicon strip tracker, and the transition-radiation drift-tube tracker. The Insertable B-Layer, a new innermost pixel layer, was installed during the shutdown period in 2014, together with modifications to the layout of the cables and support structures of the existing pixel detector. The material in the inner detector is studied with several methods, using a low-luminosity √s = 13 TeV pp collision sample corresponding to around 2.0 nb -1 collected in 2015 with the ATLAS experiment at the LHC. In this paper, the material within the innermost barrel regionmore » is studied using reconstructed hadronic interaction and photon conversion vertices. For the forward rapidity region, the material is probed by a measurement of the efficiency with which single tracks reconstructed from pixel detector hits alone can be extended with hits on the track in the strip layers. The results of these studies have been taken into account in an improved description of the material in the ATLAS inner detector simulation, resulting in a reduction in the uncertainties associated with the charged-particle reconstruction efficiency determined from simulation.« less

Precision electron-beam polarimetry at 1 GeV using diamond microstrip detectors

DOE PAGES

Narayan, A.; Jones, D.; Cornejo, J. C.; ...

2016-02-16

We report on the highest precision yet achieved in the measurement of the polarization of a low-energy, O(1 GeV), continuous-wave (CW) electron beam, accomplished using a new polarimeter based on electron-photon scattering, in Hall C at Jefferson Lab. A number of technical innovations were necessary, including a novel method for precise control of the laser polarization in a cavity and a novel diamond microstrip detector that was able to capture most of the spectrum of scattered electrons. The data analysis technique exploited track finding, the high granularity of the detector, and its large acceptance. The polarization of the 180–μA, 1.16-GeVmore » electron beam was measured with a statistical precision of <1% per hour and a systematic uncertainty of 0.59%. This exceeds the level of precision required by the Q weak experiment, a measurement of the weak vector charge of the proton. Proposed future low-energy experiments require polarization uncertainty < 0.4%, and this result represents an important demonstration of that possibility. This measurement is the first use of diamond detectors for particle tracking in an experiment. As a result, it demonstrates the stable operation of a diamond-based tracking detector in a high radiation environment, for two years.« less

An Efficient, FPGA-Based, Cluster Detection Algorithm Implementation for a Strip Detector Readout System in a Time Projection Chamber Polarimeter

NASA Technical Reports Server (NTRS)

Gregory, Kyle J.; Hill, Joanne E. (Editor); Black, J. Kevin; Baumgartner, Wayne H.; Jahoda, Keith

2016-01-01

A fundamental challenge in a spaceborne application of a gas-based Time Projection Chamber (TPC) for observation of X-ray polarization is handling the large amount of data collected. The TPC polarimeter described uses the APV-25 Application Specific Integrated Circuit (ASIC) to readout a strip detector. Two dimensional photoelectron track images are created with a time projection technique and used to determine the polarization of the incident X-rays. The detector produces a 128x30 pixel image per photon interaction with each pixel registering 12 bits of collected charge. This creates challenging requirements for data storage and downlink bandwidth with only a modest incidence of photons and can have a significant impact on the overall mission cost. An approach is described for locating and isolating the photoelectron track within the detector image, yielding a much smaller data product, typically between 8x8 pixels and 20x20 pixels. This approach is implemented using a Microsemi RT-ProASIC3-3000 Field-Programmable Gate Array (FPGA), clocked at 20 MHz and utilizing 10.7k logic gates (14% of FPGA), 20 Block RAMs (17% of FPGA), and no external RAM. Results will be presented, demonstrating successful photoelectron track cluster detection with minimal impact to detector dead-time.

Study of the performance of Micromegas detectors in magnetic field

NASA Astrophysics Data System (ADS)

Dimitrios, Sampsonidis

2018-02-01

Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

Three-Dimensional Visualization of Particle Tracks.

ERIC Educational Resources Information Center

Julian, Glenn M.

1993-01-01

Suggests ways to bring home to the introductory physics student some of the excitement of recent discoveries in particle physics. Describes particle detectors and encourages the use of the Standard Model along with real images of particle tracks to determine three-dimensional views of tracks. (MVL)

Does GEM-Encoding Clinical Practice Guidelines Improve the Quality of Knowledge Bases? A Study with the Rule-Based Formalism

PubMed Central

Georg, Gersende; Séroussi, Brigitte; Bouaud, Jacques

2003-01-01

The aim of this work was to determine whether the GEM-encoding step could improve the representation of clinical practice guidelines as formalized knowledge bases. We used the 1999 Canadian recommendations for the management of hypertension, chosen as the knowledge source in the ASTI project. We first clarified semantic ambiguities of therapeutic sequences recommended in the guideline by proposing an interpretative framework of therapeutic strategies. Then, after a formalization step to standardize the terms used to characterize clinical situations, we created the GEM-encoded instance of the guideline. We developed a module for the automatic derivation of a rule base, BR-GEM, from the instance. BR-GEM was then compared to the rule base, BR-ASTI, embedded within the critic mode of ASTI, and manually built by two physicians from the same Canadian guideline. As compared to BR-ASTI, BR-GEM is more specific and covers more clinical situations. When evaluated on 10 patient cases, the GEM-based approach led to promising results. PMID:14728173

GEMS Revealed: Spectrum Imaging of Aggregate Grains in Interplanetary Dust

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.; Christoffersen, R.

2005-01-01

Anhydrous interplanetary dust particles (IDPs) of cometary origin contain abundant materials that formed in the early solar nebula. These materials were transported outward and subsequently mixed with molecular cloud materials and presolar grains in the region where comets accreted [1]. GEMS (glass with embedded metal and sulfides) grains are a major component of these primitive anhydrous IDPs, along with crystalline Mg-rich silicates, Fe-Ni sulfides, carbonaceous material, and other trace phases. Some GEMS grains (5%) are demonstrably presolar based on their oxygen isotopic compositions [2]. However, most GEMS grains are isotopically solar and have bulk chemical compositions that are incompatible with inferred compositions of interstellar dust, suggesting a solar system origin [3]. An alternative hypothesis is that GEMS grains represent highly irradiated interstellar grains whose oxygen isotopic compositions were homogenized through processing in the interstellar medium (ISM) [4]. We have obtained the first quantitative X-ray maps (spectrum images) showing the distribution of major and minor elements in individual GEMS grains. Nanometer-scale chemical maps provide critical data required to evaluate the differing models regarding the origin of GEMS grains.

Microvesicle removal of anticancer drugs contributes to drug resistance in human pancreatic cancer cells

PubMed Central

Muralidharan-Chari, Vandhana; Kohan, Hamed Gilzad; Asimakopoulos, Alexandros G.; Sudha, Thangirala; Sell, Stewart; Kannan, Kurunthachalam; Boroujerdi, Mehdi; Davis, Paul J.; Mousa, Shaker A.

2016-01-01

High mortality in pancreatic cancer patients is partly due to resistance to chemotherapy. We describe that human pancreatic cancer cells acquire drug resistance by a novel mechanism in which they expel and remove chemotherapeutic drugs from the microenvironment via microvesicles (MVs). Using human pancreatic cancer cells that exhibit varied sensitivity to gemcitabine (GEM), we show that GEM exposure triggers the cancer cells to release MVs in an amount that correlates with that cell line's sensitivity to GEM. The importance of MV-release in gaining drug resistance in GEM-resistant pancreatic cancer cells was confirmed when the inhibition of MV-release sensitized the cells to GEM treatment, both in vitro and in vivo. Mechanistically, MVs remove drugs that are internalized into the cells and that are in the microenvironment. The differences between the drug-resistant and drug-sensitive pancreatic cancer cell lines tested here are explained based on the variable content of influx/efflux proteins present on MVs, which directly dictates the ability of MVs either to trap GEM or to allow GEM to flow back to the microenvironment. PMID:27391262

Muon production height studies with the air shower experiment KASCADE-Grande

NASA Astrophysics Data System (ADS)

Apel, W. D.; Arteaga, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Büttner, C.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; Link, K.; Ludwig, M.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Obenland, R.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schatz, G.; Schieler, H.; Schröder, F.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

2011-01-01

A large area (128 m2) muon tracking detector, located within the KASCADE experiment, has been built with the aim to identify muons (Eμ > 0.8 GeV) and their angular correlation in extensive air showers by track measurements under 18 r.l. shielding. Orientation of the muon track with respect to the shower axis is expressed in terms of the radial and tangential angles, which are the basic tools for all muon investigations with the tracking detector. By means of triangulation the muon production height is determined. Distributions of measured production heights are compared to CORSIKA shower simulations. Analysis of these heights reveals a transition from light to heavy cosmic ray primary particles with increasing shower energy in the energy region of the 'Knee' of the cosmic ray spectrum

Entwicklungsarbeit am Spurendetektor fur das CDF Experiment am Tevatron (in German/English)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartmann, Frank

2000-02-01

Silicon, the element, which revolutionized the development of electronics, is known as an important and multiusable material, dominating todays electronic technology. It's properties are well investigated and today well known. Silicon is used in solar cells, computers and telecommunications. Since the Sixties semiconductors have been used as particle detectors. Initially they were operated in fixed- target experiments as calorimeters and as detectors with a high precision track reconstruction. Since the Eighties they are widely used in collider experiments as silicon microstrip or silicon pixel detectors near the primary vertex. Silicon sensors have a very good intrinsic energy resolution: for everymore » 3.6 eV released by a particle crossing the medium, one electron-hole pair is produced. Compared to 30 eV required to ionize a gas molecule in a gaseous detector, one gets 10 times the number of particles. The average energy loss and high ionized particle number with 390 e V / μm ~ 108 (electron - hole pairs)/ μm is effectively high due to the high density of silicon. These detectors allow a high precision reconstruction of tracks, primary and secondary vertices, which are especially important for b flavour tagging. The Tevatron and its detectors are being upgraded for the next data taking run starting in 2001 (RUN II). The Collider Detector at Fermilab (CDF) [2] for the upcoming Run II and its upgraded components are described in chapter 2. The main upgrade project is the design and construction of a completely new inner tracking system.« less

Measurement of the eta-meson mass using psi(2S) --> etaJ/psi.

PubMed

Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Ge, J Y; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ernst, J; Ecklund, K M; Severini, H; Love, W; Savinov, V; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J

2007-09-21

We measure the mass of the eta meson using psi(2S) --> etaJ/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta --> gamma gamma, 3pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M(eta) = 547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM.

Measurement of the η-Meson Mass Using ψ(2S)→ηJ/ψ

NASA Astrophysics Data System (ADS)

Miller, D. H.; Sanghi, B.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Ge, J. Y.; Hu, D.; Moziak, B.; Napolitano, J.; He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Yang, F.; Artuso, M.; Blusk, S.; Khalil, S.; Li, J.; Menaa, N.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Asner, D. M.; Edwards, K. W.; Naik, P.; Briere, R. A.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Adam, N. E.; Alexander, J. P.; Cassel, D. G.; Duboscq, J. E.; Ehrlich, R.; Fields, L.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Jones, C. D.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Mahlke-Krüger, H.; Mohapatra, D.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Riley, D.; Ryd, A.; Sadoff, A. J.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; Athar, S. B.; Patel, R.; Yelton, J.; Rubin, P.; Eisenstein, B. I.; Karliner, I.; Lowrey, N.; Selen, M.; White, E. J.; Wiss, J.; Mitchell, R. E.; Shepherd, M. R.; Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Zweber, P.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Ernst, J.; Ecklund, K. M.; Severini, H.; Love, W.; Savinov, V.; Lopez, A.; Mehrabyan, S.; Mendez, H.; Ramirez, J.

2007-09-01

We measure the mass of the η meson using ψ(2S)→ηJ/ψ events acquired with the CLEO-c detector operating at the CESR e+e- collider. Using the four decay modes η→γγ, 3π0, π+π-π0, and π+π-γ, we find Mη=547.785±0.017±0.057MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5σ with the much smaller mass obtained by GEM.

Automatic HDL firmware generation for FPGA-based reconfigurable measurement and control systems with mezzanines in FMC standard

NASA Astrophysics Data System (ADS)

Wojenski, Andrzej; Kasprowicz, Grzegorz; Pozniak, Krzysztof T.; Romaniuk, Ryszard

2013-10-01

The paper describes a concept of automatic firmware generation for reconfigurable measurement systems, which uses FPGA devices and measurement cards in FMC standard. Following sections are described in details: automatic HDL code generation for FPGA devices, automatic communication interfaces implementation, HDL drivers for measurement cards, automatic serial connection between multiple measurement backplane boards, automatic build of memory map (address space), automatic generated firmware management. Presented solutions are required in many advanced measurement systems, like Beam Position Monitors or GEM detectors. This work is a part of a wider project for automatic firmware generation and management of reconfigurable systems. Solutions presented in this paper are based on previous publication in SPIE.

Automated scanning of plastic nuclear track detectors using the Minnesota star scanner

NASA Technical Reports Server (NTRS)

Fink, P. J.; Waddington, C. J.

1986-01-01

The problems found in an attempt to adapt an automated scanner of astronomical plates, the Minnesota Automated Dual Plate Scanner (APS), to locating and measuring the etch pits produced by ionizing particles in plastic nuclear track detectors (CR-39) are described. A visual study of these pits was made to determine the errors introduced in determining positions and shapes. Measurements made under a low power microscope were compared with those from the APS.

Simulation study of pixel detector charge digitization

NASA Astrophysics Data System (ADS)

Wang, Fuyue; Nachman, Benjamin; Sciveres, Maurice; Lawrence Berkeley National Laboratory Team

2017-01-01

Reconstruction of tracks from nearly overlapping particles, called Tracking in Dense Environments (TIDE), is an increasingly important component of many physics analyses at the Large Hadron Collider as signatures involving highly boosted jets are investigated. TIDE makes use of the charge distribution inside a pixel cluster to resolve tracks that share one of more of their pixel detector hits. In practice, the pixel charge is discretized using the Time-over-Threshold (ToT) technique. More charge information is better for discrimination, but more challenging for designing and operating the detector. A model of the silicon pixels has been developed in order to study the impact of the precision of the digitized charge distribution on distinguishing multi-particle clusters. The output of the GEANT4-based simulation is used to train neutral networks that predict the multiplicity and location of particles depositing energy inside one cluster of pixels. By studying the multi-particle cluster identification efficiency and position resolution, we quantify the trade-off between the number of ToT bits and low-level tracking inputs. As both ATLAS and CMS are designing upgraded detectors, this work provides guidance for the pixel module designs to meet TIDE needs. Work funded by the China Scholarship Council and the Office of High Energy Physics of the U.S. Department of Energy under contract DE-AC02-05CH11231.

The Silicon Tracking System of the CBM Experiment at FAIR

NASA Astrophysics Data System (ADS)

Heuser, Johann M.

The Compressed Baryonic Matter (CBM) experiment at FAIR will conduct a systematic research program to explore the phase diagram of strongly interacting matter at highest net baryon densities and moderate temperatures. These conditions are to be created in collisions of heavy-ion beams with nuclear targets in the projectile beam energy range of 2 to 45 GeV/nucleon, initially coming from the SIS 100 synchrotron (up to 14 GeV/nucleon) and in a next step from SIS 300 enabling studies at the highest net baryon densities. Collision rates up to 107 per second are required to produce very rare probes with unprecedented statistics in this energy range. Their signatures are complex. These conditions call for detector systems designed to meet the extreme requirements in terms of rate capability, momentum and spatial resolution, and a novel data acquisition and trigger concept which is not limited by latency but by throughput. In the paper we describe the concept and development status of CBM's central detector, the Silicon Tracking System (STS). The detector realizes a large, highly granular and redundant detector system with fast read-out, and lays specific emphasis on low material budget in its physics aperture to achieve for charged particle tracks a momentum resolution of δp/p ≈ 1% at p > 1 GeV/c, at >95% track reconstruction efficiency. The detector employs 1220 highly segmented double-sided silicon micro-strip sensors of 300 µm thickness, mounted into 896 modular structures of various types that are aggregated on 106 low-mass carbon fiber ladders of different sizes that build up the tracking stations. The read-out electronics with its supply and cooling infrastructure is arranged at the periphery of the ladders, and provides a total channel count of 1.8 million. The signal transmission from the silicon sensors to the electronics is realized through ultra-thin multi-line aluminum-polyimide cables of up to half a meter length. The electronics generates a free-streaming data flow of digitized time-stamped detector information that is sent via data aggregation boards to the first-level event selector, a computing farm for on-line event reconstruction. The power dissipated by the detector's read-out electronics, amounting to about 2 times 20 kW in two layers at the top and bottom of the detector, will be removed by a particularly efficient and space-saving bi-phase CO2 cooling. The system integration of the detector takes respect of operating the sensors in a thermal enclosure at -5 °C, to limit leakage currents originating from radiation damage, and allows for maintenance to the detector components, in particular the sensors, if they should exceed an exposure to more than 1014 1 MeV neq/cm2. The detector system is developed and built by a CBM project team comprising institutes from Germany, Russia, Poland and Ukraine.

STED microscopy visualizes energy deposition of single ions in a solid-state detector beyond diffraction limit

NASA Astrophysics Data System (ADS)

Niklas, M.; Henrich, M.; Jäkel, O.; Engelhardt, J.; Abdollahi, A.; Greilich, S.

2017-05-01

Fluorescent nuclear track detectors (FNTDs) allow for visualization of single-particle traversal in clinical ion beams. The point spread function of the confocal readout has so far hindered a more detailed characterization of the track spots—the ion’s characteristic signature left in the FNTD. Here we report on the readout of the FNTD by optical nanoscopy, namely stimulated emission depletion microscopy. It was firstly possible to visualize the track spots of carbon ions and protons beyond the diffraction limit of conventional light microscopy with a resolving power of approximately 80 nm (confocal: 320 nm). A clear discrimination of the spatial width, defined by the full width half maximum of track spots from particles (proton and carbon ions), with a linear energy transfer (LET) ranging from approximately 2-1016 keV µm-1 was possible. Results suggest that the width depends on LET but not on particle charge within the uncertainties. A discrimination of particle type by width thus does not seem possible (as well as with confocal microscopy). The increased resolution, however, could allow for refined determination of the cross-sectional area facing substantial energy deposition. This work could pave the way towards development of optical nanoscopy-based analysis of radiation-induced cellular response using cell-fluorescent ion track hybrid detectors.

Correlation of Particle Traversals with Clonogenic Survival Using Cell-Fluorescent Ion Track Hybrid Detector.

PubMed

Dokic, Ivana; Niklas, Martin; Zimmermann, Ferdinand; Mairani, Andrea; Seidel, Philipp; Krunic, Damir; Jäkel, Oliver; Debus, Jürgen; Greilich, Steffen; Abdollahi, Amir

2015-01-01

Development of novel approaches linking the physical characteristics of particles with biological responses are of high relevance for the field of particle therapy. In radiobiology, the clonogenic survival of cells is considered the gold standard assay for the assessment of cellular sensitivity to ionizing radiation. Toward further development of next generation biodosimeters in particle therapy, cell-fluorescent ion track hybrid detector (Cell-FIT-HD) was recently engineered by our group and successfully employed to study physical particle track information in correlation with irradiation-induced DNA damage in cell nuclei. In this work, we investigated the feasibility of Cell-FIT-HD as a tool to study the effects of clinical beams on cellular clonogenic survival. Tumor cells were grown on the fluorescent nuclear track detector as cell culture, mimicking the standard procedures for clonogenic assay. Cell-FIT-HD was used to detect the spatial distribution of particle tracks within colony-initiating cells. The physical data were associated with radiation-induced foci as surrogates for DNA double-strand breaks, the hallmark of radiation-induced cell lethality. Long-term cell fate was monitored to determine the ability of cells to form colonies. We report the first successful detection of particle traversal within colony-initiating cells at subcellular resolution using Cell-FIT-HD.

16 CFR 23.25 - Misuse of the word “gem.”

Code of Federal Regulations, 2014 CFR

2014-01-01

... stones possess the necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those...

16 CFR 23.25 - Misuse of the word “gem.”

Code of Federal Regulations, 2013 CFR

2013-01-01

... stones possess the necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those...

16 CFR 23.25 - Misuse of the word “gem.”

Code of Federal Regulations, 2011 CFR

2011-01-01

... stones possess the necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those...

16 CFR 23.25 - Misuse of the word “gem.”

Code of Federal Regulations, 2012 CFR

2012-01-01

... stones possess the necessary qualifications to properly be termed “gems.” Imitation diamonds and other imitation stones should not be described as “gems.” Not all diamonds or natural stones, including those...

Gravitational induction

NASA Astrophysics Data System (ADS)

Bini, Donato; Cherubini, Christian; Chicone, Carmen; Mashhoon, Bahram

2008-11-01

We study the linear post-Newtonian approximation to general relativity known as gravitoelectromagnetism (GEM); in particular, we examine the similarities and differences between GEM and electrodynamics. Notwithstanding some significant differences between them, we find that a special nonstationary metric in GEM can be employed to show explicitly that it is possible to introduce gravitational induction within GEM in close analogy with Faraday's law of induction and Lenz's law in electrodynamics. Some of the physical implications of gravitational induction are briefly discussed.

Simulacrum or Corporeal Manifestations in Antarctic Muon and Neutrino Detector Array

NASA Astrophysics Data System (ADS)

Liubarsky, Igor Romanovic

To date, Antarctic Muon and Neutrino Detector Array (AMANDA) collaboration has successfully deployed 382 optical modules at various depths in the South Polar ice sheet. The last 216 optical modules were put in place during the 1996-7 austral summer. This deployment completed a 10-stringed detector at depth between 1500-2000m (AMANDA-B). The detector has been operating successfully and taking data at a rate of 92Hz. However, due to the remoteness of location and the limited bandwidth for satellite transmission, only 5% of the latest data can be transmitted from the South Pole to the collaboration. Before the end of the 1996-7 antarctic season 6GBytes of data were carried to the rest of the world by hand. Since this data was taken while detector calibration was still being performed, it is far from ideal. Yet this sample, to date, represents the largest amount of the data taken by the 10 string detector available for analysis. A total of 11.8 hours of raw data was analysed, comprising 3,380,739 events. Of that number 2,951,118 were AMANDA-B triggers. After calibration and noise cleaning, the number of confirmed AMANDA-B triggers was further reduced to 2,880,391. From this data set a fraction of events were reconstructed without any filtering on the reconstructed direction of the final track. This resulted in 103,168 reconstructed tracks from all zenith angles. However, the full set of 2,880,391 triggers was used to reconstruct tracks, selecting only those that yielded an up-going muon. The procedure produced 25,122 tracks. Various quality criteria was then utilised to discriminate real up-going tracks from fake events mimicked by down-going muons. No real up-going events were found. My personal contribution to the AMANDA experiment has been in three main areas: hardware; I have built 40 of the first AMANDA-A modules; software; I have written subroutines for the University of Wisconsin-Madison AMANDA group's Monte Carlo; data analysis; I have analysed the early 10 string AMANDA-B data.

tkLayout: a design tool for innovative silicon tracking detectors

NASA Astrophysics Data System (ADS)

Bianchi, G.

2014-03-01

A new CMS tracker is scheduled to become operational for the LHC Phase 2 upgrade in the early 2020's. tkLayout is a software package developed to create 3d models for the design of the CMS tracker and to evaluate its fundamental performance figures. The new tracker will have to cope with much higher luminosity conditions, resulting in increased track density, harsher radiation exposure and, especially, much higher data acquisition bandwidth, such that equipping the tracker with triggering capabilities is envisaged. The design of an innovative detector involves deciding on an architecture offering the best trade-off among many figures of merit, such as tracking resolution, power dissipation, bandwidth, cost and so on. Quantitatively evaluating these figures of merit as early as possible in the design phase is of capital importance and it is best done with the aid of software models. tkLayout is a flexible modeling tool: new performance estimates and support for different detector geometries can be quickly added, thanks to its modular structure. Besides, the software executes very quickly (about two minutes), so that many possible architectural variations can be rapidly modeled and compared, to help in the choice of a viable detector layout and then to optimize it. A tracker geometry is generated from simple configuration files, defining the module types, layout and materials. Support structures are automatically added and services routed to provide a realistic tracker description. The tracker geometries thus generated can be exported to the standard CMS simulation framework (CMSSW) for full Monte Carlo studies. tkLayout has proven essential in giving guidance to CMS in studying different detector layouts and exploring the feasibility of innovative solutions for tracking detectors, in terms of design, performance and projected costs. This tool has been one of the keys to making important design decisions for over five years now and has also enabled project engineers and simulation experts to focus their efforts on other important or specific issues. Even if tkLayout was designed for the CMS tracker upgrade project, its flexibility makes it experiment-agnostic, so that it could be easily adapted to model other tracking detectors. The technology behind tkLayout is presented, as well as some of the results obtained in the context of the CMS silicon tracker design studies.

Simulation of the West African monsoon onset using the HadGEM3-RA regional climate model

NASA Astrophysics Data System (ADS)

Diallo, Ismaïla; Bain, Caroline L.; Gaye, Amadou T.; Moufouma-Okia, Wilfran; Niang, Coumba; Dieng, Mame D. B.; Graham, Richard

2014-08-01

The performance of the Hadley Centre Global Environmental Model version 3 regional climate model (HadGEM3-RA) in simulating the West African monsoon (WAM) is investigated. We focus on performance for monsoon onset timing and for rainfall totals over the June-July-August (JJA) season and on the model's representation of the underlying dynamical processes. Experiments are driven by the ERA-Interim reanalysis and follow the CORDEX experimental protocol. Simulations with the HadGEM3 global model, which shares a common physical formulation with HadGEM3-RA, are used to gain insight into the causes of HadGEM3-RA simulation errors. It is found that HadGEM3-RA simulations of monsoon onset timing are realistic, with an error in mean onset date of two pentads. However, the model has a dry bias over the Sahel during JJA of 15-20 %. Analysis suggests that this is related to errors in the positioning of the Saharan heat low, which is too far south in HadGEM3-RA and associated with an insufficient northward reach of the south-westerly low-level monsoon flow and weaker moisture convergence over the Sahel. Despite these biases HadGEM3-RA's representation of the general rainfall distribution during the WAM appears superior to that of ERA-Interim when using Global Precipitation Climatology Project or Tropical Rain Measurement Mission data as reference. This suggests that the associated dynamical features seen in HadGEM3-RA can complement the physical picture available from ERA-Interim. This approach is supported by the fact that the global HadGEM3 model generates realistic simulations of the WAM without the benefit of pseudo-observational forcing at the lateral boundaries; suggesting that the physical formulation shared with HadGEM3-RA, is able to represent the driving processes. HadGEM3-RA simulations confirm previous findings that the main rainfall peak near 10°N during June-August is maintained by a region of mid-tropospheric ascent located, latitudinally, between the cores of the African Easterly Jet and Tropical Easterly Jet that intensifies around the time of onset. This region of ascent is weaker and located further south near 5°N in the driving ERA-Interim reanalysis, for reasons that may be related to the coarser resolution or the physics of the underlying model, and this is consistent with a less realistic latitudinal rainfall profile than found in the HadGEM3-RA simulations.

Emissions of mercury in southern Africa derived from long-term observations at Cape Point, South Africa

NASA Astrophysics Data System (ADS)

Brunke, E.-G.; Ebinghaus, R.; Kock, H. H.; Labuschagne, C.; Slemr, F.

2012-08-01

Mercury emissions in South Africa have so far been estimated only by a bottom-up approach from activities and emission factors for different processes. In this paper we derive GEM/CO (GEM being gaseous elemental mercury, Hg0), GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios from plumes observed during long-term monitoring of these species at Cape Point between March 2007 and December 2009. The average observed GEM/CO, GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios were 2.40 ± 2.65 pg m-3 ppb-1 (n = 47), 62.7 ± 80.2 pg m-3 ppm-1 (n = 44), 3.61 ± 4.66 pg m-3 ppb-1 (n = 46), 35.6 ± 25.4 ppb ppm-1 (n = 52), 20.2 ± 15.5 ppb ppm-1 (n = 48), and 0.876 ± 1.106 ppb ppb-1 (n = 42), respectively. The observed CO/CO2, CH4/CO2, and CH4/CO emission ratios agree within the combined uncertainties of the observations and emissions with the ratios calculated from EDGAR (version 4.2) CO2, CO, and CH4 inventories for South Africa and southern Africa (South Africa, Lesotho, Swaziland, Namibia, Botswana, Zimbabwe, and Mozambique) in 2007 and 2008 (inventories for 2009 are not available yet). Total elemental mercury emission of 13.1, 15.2, and 16.1 t Hg yr-1 are estimated independently using the GEM/CO, GEM/CO2, and GEM/CH4 emission ratios and the annual mean CO, CO2, and CH4 emissions, respectively, of South Africa in 2007 and 2008. The average of these independent estimates of 14.8 t GEM yr-1 is much less than the total emission of 257 t Hg yr-1 shown by older inventories which are now considered to be wrong. Considering the uncertainties of our emission estimate, of the emission inventories, and the fact that emission of GEM represents 50-78 % of all mercury emissions, our estimate is comparable to the currently cited GEM emissions in 2004 and somewhat smaller than emissions in 2006. A further increase of mercury emissions due to increasing electricity consumption will lead to a more pronounced difference. A quantitative assessment of the difference and its significance, however, will require emission inventories for the years of observations (2007-2009) as well as better data on the speciation of the total mercury emissions in South Africa.

Measurement of the atmospheric muon flux with the NEMO Phase-1 detector

NASA Astrophysics Data System (ADS)

Aiello, S.; Ameli, F.; Amore, I.; Anghinolfi, M.; Anzalone, A.; Barbarino, G.; Battaglieri, M.; Bazzotti, M.; Bersani, A.; Beverini, N.; Biagi, S.; Bonori, M.; Bouhadef, B.; Brunoldi, M.; Cacopardo, G.; Capone, A.; Caponetto, L.; Carminati, G.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coniglione, R.; Cordelli, M.; Costa, M.; D'Amico, A.; De Bonis, G.; De Marzo, C.; De Rosa, G.; De Ruvo, G.; De Vita, R.; Distefano, C.; Falchini, E.; Flaminio, V.; Fratini, K.; Gabrielli, A.; Galatà, S.; Gandolfi, E.; Giacomelli, G.; Giorgi, F.; Giovanetti, G.; Grimaldi, A.; Habel, R.; Imbesi, M.; Kulikovsky, V.; Lattuada, D.; Leonora, E.; Lonardo, A.; Lo Presti, D.; Lucarelli, F.; Marinelli, A.; Margiotta, A.; Martini, A.; Masullo, R.; Migneco, E.; Minutoli, S.; Morganti, M.; Musico, P.; Musumeci, M.; Nicolau, C. A.; Orlando, A.; Osipenko, M.; Papaleo, R.; Pappalardo, V.; Piattelli, P.; Piombo, D.; Raia, G.; Randazzo, N.; Reito, S.; Ricco, G.; Riccobene, G.; Ripani, M.; Rovelli, A.; Ruppi, M.; Russo, G. V.; Russo, S.; Sapienza, P.; Sciliberto, D.; Sedita, M.; Shirokov, E.; Simeone, F.; Sipala, V.; Spurio, M.; Taiuti, M.; Trasatti, L.; Urso, S.; Vecchi, M.; Vicini, P.; Wischnewski, R.

2010-05-01

The NEMO Collaboration installed and operated an underwater detector including prototypes of the critical elements of a possible underwater km 3 neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box. The detector was developed to test some of the main systems of the km 3 detector, including the data transmission, the power distribution, the timing calibration and the acoustic positioning systems as well as to verify the capabilities of a single tridimensional detection structure to reconstruct muon tracks. We present results of the analysis of the data collected with the NEMO Mini-Tower. The position of photomultiplier tubes (PMTs) is determined through the acoustic position system. Signals detected with PMTs are used to reconstruct the tracks of atmospheric muons. The angular distribution of atmospheric muons was measured and results compared to Monte Carlo simulations.

Recent technological developments on LGAD and iLGAD detectors for tracking and timing applications

NASA Astrophysics Data System (ADS)

Pellegrini, G.; Baselga, M.; Carulla, M.; Fadeyev, V.; Fernández-Martínez, P.; García, M. Fernández; Flores, D.; Galloway, Z.; Gallrapp, C.; Hidalgo, S.; Liang, Z.; Merlos, A.; Moll, M.; Quirion, D.; Sadrozinski, H.; Stricker, M.; Vila, I.

2016-09-01

This paper reports the latest technological development on the Low Gain Avalanche Detector (LGAD) and introduces a new architecture of these detectors called inverse-LGAD (iLGAD). Both approaches are based on the standard Avalanche Photo Diodes (APD) concept, commonly used in optical and X-ray detection applications, including an internal multiplication of the charge generated by radiation. The multiplication is inherent to the basic n++-p+-p structure, where the doping profile of the p+ layer is optimized to achieve high field and high impact ionization at the junction. The LGAD structures are optimized for applications such as tracking or timing detectors for high energy physics experiments or medical applications where time resolution lower than 30 ps is required. Detailed TCAD device simulations together with the electrical and charge collection measurements are presented through this work.

Energy straggling eliminated as a limitation to charge resolution of transmission detectors. [used for particle identification

NASA Technical Reports Server (NTRS)

Tarle, G.; Ahlen, S. P.; Price, P. B.

1981-01-01

It is pointed out that detectors of the energy loss of penetrating charged particles are widely used for particle identification. These measurements are hampered, however, by fluctuations in the amount of energy deposited within the detector. It is shown that this limitation can be overcome with a new nuclear track detector, CR-39(DOP), and that the charge resolution of this detector exceeds that of any other, including semiconductor diodes.

SU-G-JeP3-10: Update On a Real-Time Treatment Guidance System Using An IR Navigation System for Pleural PDT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, M; Penjweini, R; Zhu, T

Purpose: Photodynamic therapy (PDT) is used in conjunction with surgical debulking of tumorous tissue during treatment for pleural mesothelioma. One of the key components of effective PDT is uniform light distribution. Currently, light is monitored with 8 isotropic light detectors that are placed at specific locations inside the pleural cavity. A tracking system with real-time feedback software can be utilized to improve the uniformity of light in addition to the existing detectors. Methods: An infrared (IR) tracking camera is used to monitor the movement of the light source. The same system determines the pleural geometry of the treatment area. Softwaremore » upgrades allow visualization of the pleural cavity as a two-dimensional volume. The treatment delivery wand was upgraded for ease of light delivery while incorporating the IR system. Isotropic detector locations are also displayed. Data from the tracking system is used to calculate the light fluence rate delivered. This data is also compared with in vivo data collected via the isotropic detectors. Furthermore, treatment volume information will be used to form light dose volume histograms of the pleural cavity. Results: In a phantom study, the light distribution was improved by using real-time guidance compared to the distribution when using detectors without guidance. With the tracking system, 2D data can be collected regarding light fluence rather than just the 8 discrete locations inside the pleural cavity. Light fluence distribution on the entire cavity can be calculated at every time in the treatment. Conclusion: The IR camera has been used successfully during pleural PDT patient treatment to track the motion of the light source and provide real-time display of 2D light fluence. It is possible to use the feedback system to deliver a more uniform dose of light throughout the pleural cavity.« less

Toward improved guideline quality: using the COGS statement with GEM.

PubMed

Shiffman, Richard N; Michel, Georges

2004-01-01

The Conference on Guideline Standardization (COGS) was convened to create a standardized documentation checklist for clinical practice guidelines in an effort to promote guideline quality and facilitate implementation. The statement was created by a multidisciplinary panel using a rigorous consensus development methodology. The Guideline Elements Model (GEM) provides a standardized approach to representing guideline documents using XML. In this work, we demonstrate the sufficiency of GEM for describing COGS components. Using the mapping between COGS and GEM elements we built an XSLT application to examine a guideline's adherence (or non-adherence) to the COGS checklist. Once a guideline has been marked up according to the GEM hierarchy, its knowledge content can be reused in multiple ways.

Muon trackers for imaging a nuclear reactor

NASA Astrophysics Data System (ADS)

Kume, N.; Miyadera, H.; Morris, C. L.; Bacon, J.; Borozdin, K. N.; Durham, J. M.; Fuzita, K.; Guardincerri, E.; Izumi, M.; Nakayama, K.; Saltus, M.; Sugita, T.; Takakura, K.; Yoshioka, K.

2016-09-01

A detector system for assessing damage to the cores of the Fukushima Daiichi nuclear reactors by using cosmic-ray muon tomography was developed. The system consists of a pair of drift-tube tracking detectors of 7.2× 7.2-m2 area. Each muon tracker consists of 6 x-layer and 6 y-layer drift-tube detectors. Each tracker is capable of measuring muon tracks with 12 mrad angular resolutions, and is capable of operating under 50-μ Sv/h radiation environment by removing gamma induced background with a novel time-coincidence logic. An estimated resolution to observe nuclear fuel debris at Fukushima Daiichi is 0.3 m when the core is imaged from outside the reactor building.

Characterizing transient noise in the LIGO detectors

NASA Astrophysics Data System (ADS)

Nuttall, L. K.

2018-05-01

Data from the LIGO detectors typically contain many non-Gaussian noise transients which arise due to instrumental and environmental conditions. These non-Gaussian transients can be an issue for the modelled and unmodelled transient gravitational-wave searches, as they can mask or mimic a true signal. Data quality can change quite rapidly, making it imperative to track and find new sources of transient noise so that data are minimally contaminated. Several examples of transient noise and the tools used to track them are presented. These instances serve to highlight the diverse range of noise sources present at the LIGO detectors during their second observing run. This article is part of a discussion meeting issue `The promises of gravitational-wave astronomy'.

Comparative verification between GEM model and official aviation terminal forecasts

NASA Technical Reports Server (NTRS)

Miller, Robert G.

1988-01-01

The Generalized Exponential Markov (GEM) model uses the local standard airways observation (SAO) to predict hour-by-hour the following elements: temperature, pressure, dew point depression, first and second cloud-layer height and amount, ceiling, total cloud amount, visibility, wind, and present weather conditions. GEM is superior to persistence at all projections for all elements in a large independent sample. A minute-by-minute GEM forecasting system utilizing the Automated Weather Observation System (AWOS) is under development.

Self-Delivery Nanoparticles of Amphiphilic Methotrexate-Gemcitabine Prodrug for Synergistic Combination Chemotherapy via Effect of Deoxyribonucleotide Pools.

PubMed

Wang, Yao; Huang, Ping; Hu, Minxi; Huang, Wei; Zhu, Xinyuan; Yan, Deyue

2016-11-16

The distinct and complementary biochemical mechanisms of folic acid analog methotrexate (MTX) and cytidine analog gemcitabine (GEM) make their synergistic combination effective. Unfortunately, such a combination faces severe pharmacokinetic problems and several transportation barriers. To overcome these problems, a new strategy of amphiphilic small molecule prodrug (ASMP) is developed to improve their synergistic combination effect. The ASMP was prepared by the amidation of the hydrophilic GEM with the hydrophobic MTX at a fixed ratio. Owing to its inherent amphiphilicity, the MTX-GEM ASMP self-assembled into stable nanoparticles (ASMP-NPs) with high drug loading capacity (100%), in which the MTX and GEM could self-deliver without any carriers and release synchronously in cancer cells. In vitro studies showed that the MTX-GEM ASMP-NPs could greatly improve the synergistic combination effects by the reason of arresting more S phase of the cell cycle and reducing levels of deoxythymidine triphosphate (dTTP), deoxyadenosine triphosphate (dATP), and deoxycytidine triphosphate (dCTP). The stronger synergistic effects caused the higher cell cytotoxicity and apoptotic ratio, and circumvented the multidrug resistance (MDR) of tumor cells. Additionally, MTX-GEM ASMP-NPs could achieve the same anticancer effect with the greatly reduced dosage compared with the free drugs according to the dose-reduction index (DRI) values of MTX and GEM in MTX-GEM ASMP-NPs, which may be beneficial for reducing the side effects.

Novel Micromegas trackers

NASA Astrophysics Data System (ADS)

Sabatie, Franck

2017-09-01

The latest development in Micromegas trackers includes the Micromegas Vertex Tracker (MVT) soon to be installed in Jefferson Lab Hall B, in the CLAS12 central tracking system. The MVT is composed of 6 cylindrical layers and 6 flat disks of resistive bulk Micromegas detectors. They have been designed to withstand the high particle flux environment and the high magnetic field using a low material budget of less than 0.5% of a radiation length per detector. The MVT is read out using front-end electronics based on the ``Dream'' Asic developed at CEA Saclay/Irfu. The low material budget requirements and very stringent space restrictions of the central tracking system surrounded by a 5T solenoid prevent the use of on-detector frontend electronics. The ability of the Dream chip to work with high-capacitance detectors allows deploying the electronics some 2 m away using flat micro-coaxial cables. After a short introduction to Micromegas detectors and the state-of-the-art achievements in this technology, I will focus on the CLAS12 MVT detector system, from the fabrication techniques to the readout electronics. Possible future developments will briefly be presented as well.

Tracking performance of a single-crystal and a polycrystalline diamond pixel-detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menasce, D.; et al.

2013-06-01

We present a comparative characterization of the performance of a single-crystal and a polycrystalline diamond pixel-detector employing the standard CMS pixel readout chips. Measurements were carried out at the Fermilab Test Beam Facility, FTBF, using protons of momentum 120 GeV/c tracked by a high-resolution pixel telescope. Particular attention was directed to the study of the charge-collection, the charge-sharing among adjacent pixels and the achievable position resolution. The performance of the single-crystal detector was excellent and comparable to the best available silicon pixel-detectors. The measured average detection-efficiency was near unity, ε = 0.99860±0.00006, and the position-resolution for shared hits was aboutmore » 6 μm. On the other hand, the performance of the polycrystalline detector was hampered by its lower charge collection distance and the readout chip threshold. A new readout chip, capable of operating at much lower threshold (around 1 ke $-$), would be required to fully exploit the potential performance of the polycrystalline diamond pixel-detector.« less

Gaseous elemental mercury (GEM) fluxes over canopy of two typical subtropical forests in south China

NASA Astrophysics Data System (ADS)

Yu, Qian; Luo, Yao; Wang, Shuxiao; Wang, Zhiqi; Hao, Jiming; Duan, Lei

2018-01-01

Mercury (Hg) exchange between forests and the atmosphere plays an important role in global Hg cycling. The present estimate of global emission of Hg from natural source has large uncertainty, partly due to the lack of chronical and valid field data, particularly for terrestrial surfaces in China, the most important contributor to global atmospheric Hg. In this study, the micrometeorological method (MM) was used to continuously observe gaseous elemental mercury (GEM) fluxes over forest canopy at a mildly polluted site (Qianyanzhou, QYZ) and a moderately polluted site (Huitong, HT, near a large Hg mine) in subtropical south China for a full year from January to December in 2014. The GEM flux measurements over forest canopy in QYZ and HT showed net emission with annual average values of 6.67 and 0.30 ng m-2 h-1, respectively. Daily variations of GEM fluxes showed an increasing emission with the increasing air temperature and solar radiation in the daytime to a peak at 13:00, and decreasing emission thereafter, even as a GEM sink or balance at night. High temperature and low air Hg concentration resulted in the high Hg emission in summer. Low temperature in winter and Hg absorption by plant in spring resulted in low Hg emission, or even adsorption in the two seasons. GEM fluxes were positively correlated with air temperature, soil temperature, wind speed, and solar radiation, while it is negatively correlated with air humidity and atmospheric GEM concentration. The lower emission fluxes of GEM at the moderately polluted site (HT) when compared with that in the mildly polluted site (QYZ) may result from a much higher adsorption fluxes at night in spite of a similar or higher emission fluxes during daytime. This shows that the higher atmospheric GEM concentration at HT restricted the forest GEM emission. Great attention should be paid to forests as a crucial increasing Hg emission source with the decreasing atmospheric GEM concentration in polluted areas because of Hg emission abatement in the future.

Limitations and opportunities of whole blood bilirubin measurements by GEM premier 4000®.

PubMed

Wang, Li; Albert, Arianne Y K; Jung, Benjamin; Hadad, Keyvan; Lyon, Martha E; Basso, Melanie

2017-03-29

Neonatal hyperbilirubinemia has traditionally been screened by either total serum bilirubin or transcutaneous bilirubin. Whole blood bilirubin (TwB) by the GEM Premier 4000® blood gas analyzer (GEM) is a relatively new technology and it provides fast bilirubin results with a small sample volume and can measure co-oximetry and other analytes. Our clinical study was to evaluate the reliability of TwB measured by the GEM and identify analytical and clinical factors that may contribute to possible bias. 440 consecutive healthy newborn samples that had plasma bilirubin ordered for neonatal hyperbilirubinemia screening were included. TwB was first measured using the GEM, after which the remainder of the blood was spun and plasma neonatal bilirubin was measured using the VITROS 5600® (VITROS). 62 samples (14%) were excluded from analysis due to failure in obtaining GEM results. Passing-Bablok regression suggested that the GEM results were negatively biased at low concentrations of bilirubin and positively biased at higher concentrations relative to the VITROS results (y = 1.43x-61.13). Bland-Altman plots showed an overall negative bias of the GEM bilirubin with a wide range of differences compared to VITROS. Both hemoglobin concentration and hemolysis affected the accuracy of the GEM results. Clinically, male infants had higher mean bilirubin levels, and infants delivered by caesarean section had lower hemoglobin levels. When comparing the number of results below the 40th percentile and above the 95th percentile cut-offs in the Bhutani nomogram which would trigger discharge or treatment, GEM bilirubin exhibited poor sensitivity and poor specificity in contrast to VITROS bilirubin. An imperfect correlation was observed between whole blood bilirubin measured on the GEM4000® and plasma bilirubin on the VITROS 5600®. The contributors to the observed differences between the two instruments were specimen hemolysis and the accuracy of hemoglobin measurements, the latter of which affects the calculation of plasma-equivalent bilirubin. Additionally, the lack of standardization of total bilirubin calibration particularly in newborn specimens, may also account for some of the disagreement in results.

Track reconstruction for the Mu3e experiment based on a novel Multiple Scattering fit

NASA Astrophysics Data System (ADS)

Kozlinskiy, Alexandr

2017-08-01

The Mu3e experiment is designed to search for the lepton flavor violating decay μ+ → e+e+e-. The aim of the experiment is to reach a branching ratio sensitivity of 10-16. In a first phase the experiment will be performed at an existing beam line at the Paul-Scherrer Institute (Switzerland) providing 108 muons per second, which will allow to reach a sensitivity of 2 · 10-15. The muons with a momentum of about 28 MeV/c are stopped and decay at rest on a target. The decay products (positrons and electrons) with energies below 53MeV are measured by a tracking detector consisting of two double layers of 50 μm thin silicon pixel sensors. The high granularity of the pixel detector with a pixel size of 80 μm × 80 μm allows for a precise track reconstruction in the high multiplicity environment of the Mu3e experiment, reaching 100 tracks per reconstruction frame of 50 ns in the final phase of the experiment. To deal with such high rates and combinatorics, the Mu3e track reconstruction uses a novel fit algorithm that in the simplest case takes into account only the multiple scattering, which allows for a fast online tracking on a GPU based filter farm. An implementation of the 3-dimensional multiple scattering fit based on hit triplets is described. The extension of the fit that takes into account energy losses and pixel size is used for offline track reconstruction. The algorithm and performance of the offline track reconstruction based on a full Geant4 simulation of the Mu3e detector are presented.

GPU-accelerated track reconstruction in the ALICE High Level Trigger

NASA Astrophysics Data System (ADS)

Rohr, David; Gorbunov, Sergey; Lindenstruth, Volker; ALICE Collaboration

2017-10-01

ALICE (A Large Heavy Ion Experiment) is one of the four major experiments at the Large Hadron Collider (LHC) at CERN. The High Level Trigger (HLT) is an online compute farm which reconstructs events measured by the ALICE detector in real-time. The most compute-intensive part is the reconstruction of particle trajectories called tracking and the most important detector for tracking is the Time Projection Chamber (TPC). The HLT uses a GPU-accelerated algorithm for TPC tracking that is based on the Cellular Automaton principle and on the Kalman filter. The GPU tracking has been running in 24/7 operation since 2012 in LHC Run 1 and 2. In order to better leverage the potential of the GPUs, and speed up the overall HLT reconstruction, we plan to bring more reconstruction steps (e.g. the tracking for other detectors) onto the GPUs. There are several tasks running so far on the CPU that could benefit from cooperation with the tracking, which is hardly feasible at the moment due to the delay of the PCI Express transfers. Moving more steps onto the GPU, and processing them on the GPU at once, will reduce PCI Express transfers and free up CPU resources. On top of that, modern GPUs and GPU programming APIs provide new features which are not yet exploited by the TPC tracking. We present our new developments for GPU reconstruction, both with a focus on the online reconstruction on GPU for the online offline computing upgrade in ALICE during LHC Run 3, and also taking into account how the current HLT in Run 2 can profit from these improvements.

The software peculiarities of pattern recognition in track detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Starkov, N.

The different kinds of nuclear track recognition algorithms are represented. Several complicated samples of use them in physical experiments are considered. The some processing methods of complicated images are described.

Registration of alpha particles in Makrofol-E nuclear track detectors

NASA Astrophysics Data System (ADS)

Rammah, Y. S.; Abdalla, Ayman M.; Ashraf, O.; Ashry, A. H.

2016-06-01

Fast detection of alpha particles in the range from 1 to 5 MeV in Makrofol-E polycarbonate nuclear track detectors (PCTDs) using a new chemical etchant was investigated. 252Cf and 241Am-thin open sources were used for irradiating Makrofol-E detectors with fission fragments and alpha particles in air at normal pressure and temperature (NPT). A chain of experimental work has been carried out using new etchants to register alpha particle in short time in Makrofol-E polycarbonate detectors. The etching efficiency were exhibited a clear dependence on the amount of methanol in the etching solution and etching time. The optimized chemical condition obtained at this stage of development for 200 μm Makrofol-E detectors are (8 ml of 10 N NaOH + 2 ml CH3OH) etching solutions at 60 °C for 3 h. In this study; it is possible to observe energy detection windows for Makrofol-E detectors according to applied etching duration. Makrofol-E introduced the characteristic Bragg peak, which indicates the advantages of this detector as alpha spectrometer. Consequently, the suggested new etchant can be developed for heavy ions detection and monitoring radon levels and its daughters.

Muon reconstruction with a geometrical model in JUNO

NASA Astrophysics Data System (ADS)

Genster, C.; Schever, M.; Ludhova, L.; Soiron, M.; Stahl, A.; Wiebusch, C.

2018-03-01

The Jiangmen Neutrino Underground Observatory (JUNO) is a 20 kton liquid scintillator detector currently under construction near Kaiping in China. The physics program focuses on the determination of the neutrino mass hierarchy with reactor anti-neutrinos. For this purpose, JUNO is located 650 m underground with a distance of 53 km to two nuclear power plants. As a result, it is exposed to a muon flux that requires a precise muon reconstruction to make a veto of cosmogenic backgrounds viable. Established muon tracking algorithms use time residuals to a track hypothesis. We developed an alternative muon tracking algorithm that utilizes the geometrical shape of the fastest light. It models the full shape of the first, direct light produced along the muon track. From the intersection with the spherical PMT array, the track parameters are extracted with a likelihood fit. The algorithm finds a selection of PMTs based on their first hit times and charges. Subsequently, it fits on timing information only. On a sample of through-going muons with a full simulation of readout electronics, we report a spatial resolution of 20 cm of distance from the detector's center and an angular resolution of 1.6o over the whole detector. Additionally, a dead time estimation is performed to measure the impact of the muon veto. Including the step of waveform reconstruction on top of the track reconstruction, a loss in exposure of only 4% can be achieved compared to the case of a perfect tracking algorithm. When including only the PMT time resolution, but no further electronics simulation and waveform reconstruction, the exposure loss is only 1%.

A study of amplifying the response of an LR115 solid state track detector by combining it with electret.

PubMed

Nikezić, D; Krstić, D

1995-12-01

Radon progeny are positively charged immediately after formation. A negatively charged electret collects radon progeny atoms which are produced in the diffusion chamber. The detector sensitivity may be increased by using an electret in front of solid state nuclear track detector. Dependence of detection sensitivity on distance between electret and detector LR115 II is studied theoretically and experimentally in this paper. A relatively small fraction of 218Po atoms that formed in the diffusion chamber are collected by the electret. We estimated that the attracted fraction of 218Po was 17% while the attracted fraction of 214Bi-214Po is considerably larger and amounted to approximately 60%. These results confirm previous finding that 218Po atoms discharge quickly after their formation. The comparative radon measurements using diffusion chambers with and without electrets were performed. The amplification of detector sensitivity due to the electret amounted to approximately 80%.

A novel method for quantification of beam's-eye-view tumor tracking performance.

PubMed

Hu, Yue-Houng; Myronakis, Marios; Rottmann, Joerg; Wang, Adam; Morf, Daniel; Shedlock, Daniel; Baturin, Paul; Star-Lack, Josh; Berbeco, Ross

2017-11-01

In-treatment imaging using an electronic portal imaging device (EPID) can be used to confirm patient and tumor positioning. Real-time tumor tracking performance using current digital megavolt (MV) imagers is hindered by poor image quality. Novel EPID designs may help to improve quantum noise response, while also preserving the high spatial resolution of the current clinical detector. Recently investigated EPID design improvements include but are not limited to multi-layer imager (MLI) architecture, thick crystalline and amorphous scintillators, and phosphor pixilation and focusing. The goal of the present study was to provide a method of quantitating improvement in tracking performance as well as to reveal the physical underpinnings of detector design that impact tracking quality. The study employs a generalizable ideal observer methodology for the quantification of tumor tracking performance. The analysis is applied to study both the effect of increasing scintillator thickness on a standard, single-layer imager (SLI) design as well as the effect of MLI architecture on tracking performance. The present study uses the ideal observer signal-to-noise ratio (d') as a surrogate for tracking performance. We employ functions which model clinically relevant tasks and generalized frequency-domain imaging metrics to connect image quality with tumor tracking. A detection task for relevant Cartesian shapes (i.e., spheres and cylinders) was used to quantitate trackability of cases employing fiducial markers. Automated lung tumor tracking algorithms often leverage the differences in benign and malignant lung tissue textures. These types of algorithms (e.g., soft-tissue localization - STiL) were simulated by designing a discrimination task, which quantifies the differentiation of tissue textures, measured experimentally and fit as a power-law in trend (with exponent β) using a cohort of MV images of patient lungs. The modeled MTF and NPS were used to investigate the effect of scintillator thickness and MLI architecture on tumor tracking performance. Quantification of MV images of lung tissue as an inverse power-law with respect to frequency yields exponent values of β = 3.11 and 3.29 for benign and malignant tissues, respectively. Tracking performance with and without fiducials was found to be generally limited by quantum noise, a factor dominated by quantum detective efficiency (QDE). For generic SLI construction, increasing the scintillator thickness (gadolinium oxysulfide - GOS) from a standard 290 μm to 1720 μm reduces noise to about 10%. However, 81% of this reduction is appreciated between 290 and 1000 μm. In comparing MLI and SLI detectors of equivalent individual GOS layer thickness, the improvement in noise is equal to the number of layers in the detector (i.e., 4) with almost no difference in MTF. Further, improvement in tracking performance was slightly less than the square-root of the reduction in noise, approximately 84-90%. In comparing an MLI detector with an SLI with a GOS scintillator of equivalent total thickness, improvement in object detectability is approximately 34-39%. We have presented a novel method for quantification of tumor tracking quality and have applied this model to evaluate the performance of SLI and MLI EPID designs. We showed that improved tracking quality is primarily limited by improvements in NPS. When compared to very thick scintillator SLI, employing MLI architecture exhibits the same gains in QDE, but by mitigating the effect of optical Swank noise, results in more dramatic improvements in tracking performance. © 2017 American Association of Physicists in Medicine.

The drift chamber array at the external target facility in HIRFL-CSR

NASA Astrophysics Data System (ADS)

Sun, Y. Z.; Sun, Z. Y.; Wang, S. T.; Duan, L. M.; Sun, Y.; Yan, D.; Tang, S. W.; Yang, H. R.; Lu, C. G.; Ma, P.; Yu, Y. H.; Zhang, X. H.; Yue, K.; Fang, F.; Su, H.

2018-06-01

A drift chamber array at the External Target Facility in HIRFL-CSR has been constructed for three-dimensional particle tracking in high-energy radioactive ion beam experiments. The design, readout, track reconstruction program and calibration procedures for the detector are described. The drift chamber array was tested in a 311 AMeV 40Ar beam experiment. The detector performance based on the measurements of the beam test is presented. A spatial resolution of 230 μm is achieved.

The Remote Detection of Alpha-Radioactive Nucleus Decay

NASA Astrophysics Data System (ADS)

Gurkovskiy, Boris; Miroshnichenko, Vladimir; Onishchenko, Evgeny; Simakov, Andrey; Streil, Thomas

Results of the new device design for the alpha-radiation remote detection are presented. Negative ions from the alpha particle tracks are detected by the discharge wire counter opened to air. Ion clusters being transferred from the particle tracks to the detector volume by an air flux. The detector works in a counting mode that provides sharp selectivity and accuracy of measurements. The basic parameters of the device are: detecting distance -0.5 m; measurement time -30 s; the square sensitivity -0.05 Bq/cm2.

3D Observation of GEMS by Electron Tomography

NASA Technical Reports Server (NTRS)

Matsuno, Junya; Miyake, Akira; Tsuchiyama, Akira; Nakamura-Messenger, Keiko; Messenger, Scott

2014-01-01

Amorphous silicates in chondritic porous interplanetary dust particles (CP-IDPs) coming from comets are dominated by glass with embedded metal and sulfides (GEMS). GEMS grains are submicron-sized rounded objects (typically 100-500) nm in diameter) with anaometer-sized (10-50 nm) Fe-Ni metal and sulfide grains embedded in an amorphous silicate matrix. Several formation processes for GEMS grains have been proposed so far, but these models are still being debated [2-5]. Bradley et al. proposed that GEMS grains are interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk and that they are amorphiation products of crystalline silicates in the interstellar medium by sputter-deposition of cosmic ray irradiation, similar to space weathering [2,4]. This consideration is based on the observation of nano-sized crystals (approximately 10 nm) called relict grains in GEMS grains and their shapes are pseudomorphs to the host GEMS grains. On the other hand, Keller and Messenger proposed that most GEMS formed in the protoplanetary disk as condensates from high temperature gas [3,5]. This model is based on the fact that most GEMS grains have solar isotopic compositions and have extremely heterogeneous and non-solar elemental compositions. Keller and Messenger (2011) also reported that amorphous silicates in GEMS grains are surrounded by sulfide grains, which formed as sulfidization of metallic iron grains located on the GEMS surface. The previous studies were performed with 2D observation by using transmission electron microscopy (TEM) or scanning TEM (STEM). In order to understand the structure of GEMS grains described above more clearly, we observed 3D structure of GEMS grains by electron tomography using a TEM/STEM (JEM-2100F, JEOL) at Kyoto University. Electron tomography gives not only 3D structures but also gives higher spatial resolution (approximately a few nm) than that in conventional 2D image, which is restricted by sample thickness ) approx. or greater than 50 nm). Three cluster IDPs (L2036AA5 cluster4, L2009L8 cluster 13 and W726A2) were used for the observations. ID W726A2 was collected without silicon oil, which is ordinary used to collect IDPs, so this sample has no possibility of contaminations caused by silicon oil or solvent to rinse it [6]. The samples were embedded in epoxy risin and sliced into ultrathin sections (50-300 nm) using an ultramicotome. The sections were observed by BF-TEM and HAADF-STEM (high angle annular dark field-scanning TEM) modes. Images were obtained by rotating the sample tilt angle over a range of +/- 65 deg in 1 deg steps. The obtained images were reconstructed to slice images. Mineral phases in the slice images were estimated by comparing with a 2D elemental map obtained by an EDS (energy dispersive X-ray spectroscopy) system equipped in the TEM/STEM. Careful examination of the slice images confirmed that iron grains are embedded in the amorphous silicate matrix of the GEMS grains, but sulfide grains were mainly present on the surface of the amorphous silicate. These results are consistent with the model that GEMS grains formed as condensates [3,5], although more data are needed to conclude the origin of GEMS grains. The present study is the first successful example adapting the electron tomography to the IDPs. This type of analysis will be important for planetary material sciences in the future.

Natural and anthropogenic atmospheric mercury in the European Arctic: a speciation study

NASA Astrophysics Data System (ADS)

Steen, A. O.; Berg, T.; Dastoor, A. P.; Durnford, D. A.; Hole, L. R.; Pfaffhuber, K. A.

2010-11-01

It is agreed that gaseous elemental mercury (GEM) is converted to reactive gaseous mercury (RGM) during springtime Atmospheric Mercury Depletion Event (AMDE). RGM is associated with aerosols (PHg) provided that there are sufficient aerosols available for the conversion from RGM to PHg to occur. This study reports the longest time series of GEM, RGM and PHg concentrations from a European Arctic site. From 27 April 2007 until 31 December 2008 composite GEM, RGM and PHg measurements were conducted in Ny-Ålesund (78°54' N, 11°53' E). The average concentrations of the complete dataset were 1.62±0.3 ng m-3, 8±13 pgm-3 and 8±25 pgm-3 for GEM, RGM and PHg, respectively. The study revealed a clear seasonal distribution of GEM, RGM and PHg previously undiscovered. For the complete dataset the atmospheric mercury distribution was 99% GEM, whereas RGM and PHg constituted <1%. Increased PHg concentration occurred exclusively from March through April, and constituted on average 75% of the reactive mercury species in the respective period. RGM was suggested as the precursor for the PHg existence, but long range transportation of PHg has to be taken into consideration. Surprisingly, RGM was not solely formed during the spring AMDE season. Environment Canada's Global/Regional Atmospheric Heavy Metal model (GRAHM) suggested that in situ oxidation of GEM by ozone may be producing the increased RGM concentrations from March through August. Most likely, in situ oxidation of GEM by BrO produced the observed RGM from March through August. The AMDEs occurred from late March until mid June and were thought to be of non-local origin, with GEM being transported to the study site by a wide variety of air masses. With some exceptions, no clear meteorological regime was associated with the GEM, RGM and PHg concentrations.

Gemfibrozil, a lipid-lowering drug, upregulates IL-1 receptor antagonist in mouse cortical neurons: implications for neuronal self-defense.

PubMed

Corbett, Grant T; Roy, Avik; Pahan, Kalipada

2012-07-15

Chronic inflammation is becoming a hallmark of several neurodegenerative disorders and accordingly, IL-1β, a proinflammatory cytokine, is implicated in the pathogenesis of neurodegenerative diseases. Although IL-1β binds to its high-affinity receptor, IL-1R, and upregulates proinflammatory signaling pathways, IL-1R antagonist (IL-1Ra) adheres to the same receptor and inhibits proinflammatory cell signaling. Therefore, upregulation of IL-1Ra is considered important in attenuating inflammation. The present study underlines a novel application of gemfibrozil (gem), a Food and Drug Administration-approved lipid-lowering drug, in increasing the expression of IL-1Ra in primary mouse and human neurons. Gem alone induced an early and pronounced increase in the expression of IL-1Ra in primary mouse cortical neurons. Activation of type IA p110α PI3K and Akt by gem and abrogation of gem-induced upregulation of IL-1Ra by inhibitors of PI3K and Akt indicate a role of the PI3K-Akt pathway in the upregulation of IL-1Ra. Gem also induced the activation of CREB via the PI3K-Akt pathway, and small interfering RNA attenuation of CREB abolished the gem-mediated increase in IL-1Ra. Furthermore, gem was able to protect neurons from IL-1β insult. However, small interfering RNA knockdown of neuronal IL-1Ra abrogated the protective effect of gem against IL-1β, suggesting that this drug increases the defense mechanism of cortical neurons via upregulation of IL-1Ra. Taken together, these results highlight the importance of the PI3K-Akt-CREB pathway in mediating gem-induced upregulation of IL-1Ra in neurons and suggest gem as a possible therapeutic treatment for propagating neuronal self-defense in neuroinflammatory and neurodegenerative disorders.

Complete Tem-Tomography: 3D Structure of Gems Cluster

NASA Technical Reports Server (NTRS)

Matsuno, J.; Miyake, A.; Tsuchiyama, A.; Messenger, S.; Nakamura-Messenger, K.

2015-01-01

GEMS (glass with embedded metal and sulfide) grains in interplanetary dust particles (IDPs) are considered to be one of the ubiquitous and fundamental building blocks of solids in the Solar System. They have been considered to be interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk but the elemental and isotopic composition measurements suggest that most of them have been formed in the protoplanetary disk as condensates from high temperature gas. This formation model is also supported by the formation of GEMS-like grains with respect to the size, mineral assemblage, texture and infrared spectrum by condensation experiments from mean GEMS composition materials. Previous GEMS studies were performed only with 2D observation by transmission electron microscopy (TEM) or scanning TEM (STEM). However, the 3D shape and structure of GEMS grains and the spatial distribution of Fe/FeS's has critical information about their formation and origin. Recently, the 3D structure of GEMS grains in ultrathin sections of cluster IDPs was revealed by electron tomography using a TEM/STEM (JEM-2100F, JEOL). However, CT images of thin sections mounted on Cu grids acquired by conventional TEM-tomography are limited to low tilt angles (e. g., less than absolute value of 75 deg. In fact, previous 3D TEM observations of GEMS were affected by some artifacts related to the limited tilt range in the TEM used. Complete tomographic images should be acquired by rotating the sample tilt angle over a range of more than absolute value of 80 deg otherwise the CT images lose their correct structures. In order to constrain the origin and formation process of GEMS grains more clearly, we performed complete electron tomography for GEMS grains. Here we report the sample preparation method we have developed for this study, and the preliminary results.

Crystal Identification in Dual-Layer-Offset DOI-PET Detectors Using Stratified Peak Tracking Based on SVD and Mean-Shift Algorithm

NASA Astrophysics Data System (ADS)

Wei, Qingyang; Dai, Tiantian; Ma, Tianyu; Liu, Yaqiang; Gu, Yu

2016-10-01

An Anger-logic based pixelated PET detector block requires a crystal position map (CPM) to assign the position of each detected event to a most probable crystal index. Accurate assignments are crucial to PET imaging performance. In this paper, we present a novel automatic approach to generate the CPMs for dual-layer offset (DLO) PET detectors using a stratified peak tracking method. In which, the top and bottom layers are distinguished by their intensity difference and the peaks of the top and bottom layers are tracked based on a singular value decomposition (SVD) and mean-shift algorithm in succession. The CPM is created by classifying each pixel to its nearest peak and assigning the pixel with the crystal index of that peak. A Matlab-based graphical user interface program was developed including the automatic algorithm and a manual interaction procedure. The algorithm was tested for three DLO PET detector blocks. Results show that the proposed method exhibits good performance as well as robustness for all the three blocks. Compared to the existing methods, our approach can directly distinguish the layer and crystal indices using the information of intensity and offset grid pattern.

Limitation of Gravitational Wave Detector Niobè Sensitivity by the Frequency Tracking Noise

NASA Astrophysics Data System (ADS)

Frajuca, Carlos; Bortoli, Fabio Da Silva

The gravity wave detector at the University of Western Australia was based on a bending flap of 0.45kg tuned near the fundamental resonant frequency of a 1.5ton resonant-bar of 710Hz at a temperature of 5K. The displacement of the bending flap was monitored with a 9.5GHz superconducting re-entrant cavity transducer. The performance of the transducer is related to the development of a low noise microwave pump oscillator to drive the transducer. This work studies the influence of the frequency tracking noise of Niobè. It had a burst sensitivity of h ≈ 7 × 10-19 with a long term operation from 1993 to early 1998. It had the lowest observed noise temperature. Using the characteristics of the detector, NIOBÈ should had reached a much better sensitivity that the one measure. It seems that the noise introduced in the system by the frequency tracking device was not taken into account at the time of operation, this noise gives a value of ≈ 2.5 × 10-18m/(Hz)-1/2, what is the value that limited the detector sensitivity to the one measured at the time of operation.

The development and evaluation of mini-GEMs - short, focused, online e-learning videos in geriatric medicine.

PubMed

Garside, Mark J; Fisher, James M; Blundell, Adrian G; Gordon, Adam L

2018-01-01

Mini Geriatric E-Learning Modules (Mini-GEMs) are short, focused, e-learning videos on geriatric medicine topics, hosted on YouTube, which are targeted at junior doctors working with older people. This study aimed to explore how these resources are accessed and used. The authors analyzed the viewing data from 22 videos published over the first 18 months of the Mini-GEM project. We conducted a focus group of U.K. junior doctors considering their experiences with Mini-GEMS. The Mini-GEMs were viewed 10,291 times over 18 months, equating to 38,435 minutes of total viewing time. The average viewing time for each video was 3.85 minutes. Learners valued the brevity and focused nature of the Mini-GEMs and reported that they watched them in a variety of settings to supplement clinical experiences and consolidate learning. Watching the videos led to an increase in self-reported confidence in managing older patients. Mini-GEMs can effectively disseminate clinical teaching material to a wide audience. The videos are valued by junior doctors due to their accessibility and ease of use.

Dosimetry in radiobiological studies with the heavy ion beam of the Warsaw cyclotron

NASA Astrophysics Data System (ADS)

Kaźmierczak, U.; Banaś, D.; Braziewicz, J.; Czub, J.; Jaskóła, M.; Korman, A.; Kruszewski, M.; Lankoff, A.; Lisowska, H.; Malinowska, A.; Stępkowski, T.; Szefliński, Z.; Wojewódzka, M.

2015-12-01

The aim of this study was to verify various dosimetry methods in the irradiation of biological materials with a 12C ion beam at the Heavy Ion Laboratory of the University of Warsaw. To this end the number of ions hitting the cell nucleus, calculated on the basis of the Si-detector system used in the set-up, was compared with the number of ion tracks counted in irradiated Solid State Nuclear Track Detectors and with the number of ion tracks detected in irradiated Chinese Hamster Ovary cells processed for the γ-H2AX assay. Tests results were self-consistent and confirmed that the system serves its dosimetric purpose.

Proton Radiography With Timepix Based Time Projection Chambers.

PubMed

Biegun, Aleksandra K; Visser, Jan; Klaver, Tom; Ghazanfari, Nafiseh; van Goethem, Marc-Jan; Koffeman, Els; van Beuzekom, Martin; Brandenburg, Sytze

2016-04-01

The development of a proton radiography system to improve the imaging of patients in proton beam therapy is described. The system comprises gridpix based time projection chambers, which are based on the Timepix chip designed by the Medipix collaboration, for tracking the protons. This type of detector was chosen to have minimal impact on the actual determination of the proton tracks by the tracking detectors. To determine the residual energy of the protons, a BaF 2 crystal with a photomultiplier tube is used. We present data taken in a feasibility experiment with phantoms that represent tissue equivalent materials found in the human body. The obtained experimental results show a good agreement with the performed simulations.

Muon Energy Calibration of the MINOS Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyagawa, Paul S.

MINOS is a long-baseline neutrino oscillation experiment designed to search for conclusive evidence of neutrino oscillations and to measure the oscillation parameters precisely. MINOS comprises two iron tracking calorimeters located at Fermilab and Soudan. The Calibration Detector at CERN is a third MINOS detector used as part of the detector response calibration programme. A correct energy calibration between these detectors is crucial for the accurate measurement of oscillation parameters. This thesis presents a calibration developed to produce a uniform response within a detector using cosmic muons. Reconstruction of tracks in cosmic ray data is discussed. This data is utilized tomore » calculate calibration constants for each readout channel of the Calibration Detector. These constants have an average statistical error of 1.8%. The consistency of the constants is demonstrated both within a single run and between runs separated by a few days. Results are presented from applying the calibration to test beam particles measured by the Calibration Detector. The responses are calibrated to within 1.8% systematic error. The potential impact of the calibration on the measurement of oscillation parameters by MINOS is also investigated. Applying the calibration reduces the errors in the measured parameters by ~ 10%, which is equivalent to increasing the amount of data by 20%.« less

Test beam demonstration of silicon microstrip modules with transverse momentum discrimination for the future CMS tracking detector

NASA Astrophysics Data System (ADS)

Adam, W.; Bergauer, T.; Brondolin, E.; Dragicevic, M.; Friedl, M.; Frühwirth, R.; Hoch, M.; Hrubec, J.; König, A.; Steininger, H.; Treberspurg, W.; Waltenberger, W.; Alderweireldt, S.; Beaumont, W.; Janssen, X.; Lauwers, J.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Beghin, D.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Luetic, J.; Maerschalk, T.; Marinov, A.; Postiau, N.; Randle-Conde, A.; Seva, T.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Wang, Q.; Yang, Y.; Zenoni, F.; Zhang, F.; Abu Zeid, S.; Blekman, F.; De Bruyn, I.; De Clercq, J.; D'Hondt, J.; Deroover, K.; Lowette, S.; Moortgat, S.; Moreels, L.; Python, Q.; Skovpen, K.; Van Mulders, P.; Van Parijs, I.; Bakhshiansohi, H.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; Delaere, C.; Delcourt, M.; De Visscher, S.; Francois, B.; Giammanco, A.; Jafari, A.; Cabrera Jamoulle, J.; De Favereau De Jeneret, J.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Michotte, D.; Musich, M.; Piotrzkowski, K.; Quertenmont, L.; Szilasi, N.; Vidal Marono, M.; Wertz, S.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Härkönen, J.; Lampén, T.; Luukka, P.; Peltola, T.; Tuominen, E.; Tuovinen, E.; Eerola, P.; Baulieu, G.; Boudoul, G.; Caponetto, L.; Combaret, C.; Contardo, D.; Dupasquier, T.; Gallbit, G.; Lumb, N.; Mirabito, L.; Perries, S.; Vander Donckt, M.; Viret, S.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bonnin, C.; Brom, J.-M.; Chabert, E.; Chanon, N.; Charles, L.; Conte, E.; Fontaine, J.-Ch.; Gross, L.; Hosselet, J.; Jansova, M.; Tromson, D.; Autermann, C.; Feld, L.; Karpinski, W.; Kiesel, K. M.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Pierschel, G.; Preuten, M.; Rauch, M.; Schael, S.; Schomakers, C.; Schulz, J.; Schwering, G.; Wlochal, M.; Zhukov, V.; Pistone, C.; Fluegge, G.; Kuensken, A.; Pooth, O.; Stahl, A.; Aldaya, M.; Asawatangtrakuldee, C.; Beernaert, K.; Bertsche, D.; Contreras-Campana, C.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Gallo, E.; Garay Garcia, J.; Hansen, K.; Haranko, M.; Harb, A.; Hauk, J.; Keaveney, J.; Kalogeropoulos, A.; Kleinwort, C.; Lohmann, W.; Mankel, R.; Maser, H.; Mittag, G.; Muhl, C.; Mussgiller, A.; Pitzl, D.; Reichelt, O.; Savitskyi, M.; Schuetze, P.; Walsh, R.; Zuber, A.; Biskop, H.; Buhmann, P.; Centis-Vignali, M.; Garutti, E.; Haller, J.; Hoffmann, M.; Klanner, R.; Matysek, M.; Perieanu, A.; Scharf, Ch.; Schleper, P.; Schmidt, A.; Schwandt, J.; Sonneveld, J.; Steinbrück, G.; Vormwald, B.; Wellhausen, J.; Abbas, M.; Amstutz, C.; Barvich, T.; Barth, Ch.; Boegelspacher, F.; De Boer, W.; Butz, E.; Casele, M.; Colombo, F.; Dierlamm, A.; Freund, B.; Hartmann, F.; Heindl, S.; Husemann, U.; Kornmeyer, A.; Kudella, S.; Muller, Th.; Printz, M.; Simonis, H. J.; Steck, P.; Weber, M.; Weiler, Th.; Anagnostou, G.; Asenov, P.; Assiouras, P.; Daskalakis, G.; Kyriakis, A.; Loukas, D.; Paspalaki, L.; Siklér, F.; Veszprémi, V.; Bhardwaj, A.; Dalal, R.; Jain, G.; Ranjan, K.; Dutta, S.; Chowdhury, S. Roy; Bakhshiansohl, H.; Behnamian, H.; Khakzad, M.; Naseri, M.; Cariola, P.; Creanza, D.; De Palma, M.; De Robertis, G.; Fiore, L.; Franco, M.; Loddo, F.; Sala, G.; Silvestris, L.; Maggi, G.; My, S.; Selvaggi, G.; Albergo, S.; Costa, S.; Di Mattia, A.; Giordano, F.; Potenza, R.; Saizu, M. A.; Tricomi, A.; Tuve, C.; Barbagli, G.; Brianzi, M.; Ciaranfi, R.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Latino, G.; Lenzi, P.; Meschini, M.; Paoletti, S.; Russo, L.; Scarlini, E.; Sguazzoni, G.; Strom, D.; Viliani, L.; Ferro, F.; Lo Vetere, M.; Robutti, E.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Malvezzi, S.; Manzoni, R. A.; Menasce, D.; Moroni, L.; Pedrini, D.; Azzi, P.; Bacchetta, N.; Bisello, D.; Dall'Osso, M.; Pozzobon, N.; Tosi, M.; De Canio, F.; Gaioni, L.; Manghisoni, M.; Nodari, B.; Riceputi, E.; Re, V.; Traversi, G.; Comotti, D.; Ratti, L.; Alunni Solestizi, L.; Biasini, M.; Bilei, G. M.; Cecchi, C.; Checcucci, B.; Ciangottini, D.; Fanò, L.; Gentsos, C.; Ionica, M.; Leonardi, R.; Manoni, E.; Mantovani, G.; Marconi, S.; Mariani, V.; Menichelli, M.; Modak, A.; Morozzi, A.; Moscatelli, F.; Passeri, D.; Placidi, P.; Postolache, V.; Rossi, A.; Saha, A.; Santocchia, A.; Storchi, L.; Spiga, D.; Androsov, K.; Azzurri, P.; Arezzini, S.; Bagliesi, G.; Basti, A.; Boccali, T.; Borrello, L.; Bosi, F.; Castaldi, R.; Ciampa, A.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Magazzu, G.; Martini, L.; Mazzoni, E.; Messineo, A.; Moggi, A.; Morsani, F.; Palla, F.; Palmonari, F.; Raffaelli, F.; Rizzi, A.; Savoy-Navarro, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Bellan, R.; Costa, M.; Covarelli, R.; Da Rocha Rolo, M.; Demaria, N.; Rivetti, A.; Dellacasa, G.; Mazza, G.; Migliore, E.; Monteil, E.; Pacher, L.; Ravera, F.; Solano, A.; Fernandez, M.; Gomez, G.; Jaramillo Echeverria, R.; Moya, D.; Gonzalez Sanchez, F. J.; Vila, I.; Virto, A. L.; Abbaneo, D.; Ahmed, I.; Albert, E.; Auzinger, G.; Berruti, G.; Bianchi, G.; Blanchot, G.; Bonnaud, J.; Caratelli, A.; Ceresa, D.; Christiansen, J.; Cichy, K.; Daguin, J.; D'Auria, A.; Detraz, S.; Deyrail, D.; Dondelewski, O.; Faccio, F.; Frank, N.; Gadek, T.; Gill, K.; Honma, A.; Hugo, G.; Jara Casas, L. M.; Kaplon, J.; Kornmayer, A.; Kottelat, L.; Kovacs, M.; Krammer, M.; Lenoir, P.; Mannelli, M.; Marchioro, A.; Marconi, S.; Mersi, S.; Martina, S.; Michelis, S.; Moll, M.; Onnela, A.; Orfanelli, S.; Pavis, S.; Peisert, A.; Pernot, J.-F.; Petagna, P.; Petrucciani, G.; Postema, H.; Rose, P.; Tropea, P.; Troska, J.; Tsirou, A.; Vasey, F.; Vichoudis, P.; Verlaat, B.; Zwalinski, L.; Bachmair, F.; Becker, R.; di Calafiori, D.; Casal, B.; Berger, P.; Djambazov, L.; Donega, M.; Grab, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meinhard, M.; Perozzi, L.; Roeser, U.; Starodumov, A.; Tavolaro, V.; Wallny, R.; Zhu, D.; Amsler, C.; Bösiger, K.; Caminada, L.; Canelli, F.; Chiochia, V.; de Cosa, A.; Galloni, C.; Hreus, T.; Kilminster, B.; Lange, C.; Maier, R.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Taroni, S.; Yang, Y.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Kaestli, H.-C.; Kotlinski, D.; Langenegger, U.; Meier, B.; Rohe, T.; Streuli, S.; Chen, P.-H.; Dietz, C.; Grundler, U.; Hou, W.-S.; Lu, R.-S.; Moya, M.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Jacob, J.; Seif El Nasr-Storey, S.; Cole, J.; Hoad, C.; Hobson, P.; Morton, A.; Reid, I. D.; Auzinger, G.; Bainbridge, R.; Dauncey, P.; Fulcher, J.; Hall, G.; James, T.; Magnan, A.-M.; Pesaresi, M.; Raymond, D. M.; Uchida, K.; Braga, D.; Coughlan, J. A.; Harder, K.; Jones, L.; Ilic, J.; Murray, P.; Prydderch, M.; Tomalin, I. R.; Garabedian, A.; Heintz, U.; Narain, M.; Nelson, J.; Sagir, S.; Speer, T.; Swanson, J.; Tersegno, D.; Watson-Daniels, J.; Chertok, M.; Conway, J.; Conway, R.; Flores, C.; Lander, R.; Pellett, D.; Ricci-Tam, F.; Squires, M.; Thomson, J.; Yohay, R.; Burt, K.; Ellison, J.; Hanson, G.; Olmedo, M.; Si, W.; Yates, B. R.; Gerosa, R.; Sharma, V.; Vartak, A.; Yagil, A.; Zevi Della Porta, G.; Dutta, V.; Gouskos, L.; Incandela, J.; Kyre, S.; Mullin, S.; Qu, H.; White, D.; Dominguez, A.; Bartek, R.; Cumalat, J. P.; Ford, W. T.; Jensen, F.; Johnson, A.; Krohn, M.; Leontsinis, S.; Mulholland, T.; Stenson, K.; Wagner, S. R.; Apresyan, A.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chramowicz, J.; Christian, D.; Cooper, W. E.; Deptuch, G.; Derylo, G.; Gingu, C.; Grünendahl, S.; Hasegawa, S.; Hoff, J.; Howell, J.; Hrycyk, M.; Jindariani, S.; Johnson, M.; Kahlid, F.; Lei, C. M.; Lipton, R.; Lopes De Sá, R.; Liu, T.; Los, S.; Matulik, M.; Merkel, P.; Nahn, S.; Prosser, A.; Rivera, R.; Schneider, B.; Sellberg, G.; Shenai, A.; Spiegel, L.; Tran, N.; Uplegger, L.; Voirin, E.; Berry, D. R.; Chen, X.; Ennesser, L.; Evdokimov, A.; Evdokimov, O.; Gerber, C. E.; Hofman, D. J.; Makauda, S.; Mills, C.; Sandoval Gonzalez, I. D.; Alimena, J.; Antonelli, L. J.; Francis, B.; Hart, A.; Hill, C. S.; Parashar, N.; Stupak, J.; Bortoletto, D.; Bubna, M.; Hinton, N.; Jones, M.; Miller, D. H.; Shi, X.; Tan, P.; Baringer, P.; Bean, A.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Wilson, G.; Ivanov, A.; Mendis, R.; Mitchell, T.; Skhirtladze, N.; Taylor, R.; Anderson, I.; Fehling, D.; Gritsan, A.; Maksimovic, P.; Martin, C.; Nash, K.; Osherson, M.; Swartz, M.; Xiao, M.; Acosta, J. G.; Cremaldi, L. M.; Oliveros, S.; Perera, L.; Summers, D.; Bloom, K.; Claes, D. R.; Fangmeier, C.; Gonzalez Suarez, R.; Monroy, J.; Siado, J.; Hahn, K.; Sevova, S.; Sung, K.; Trovato, M.; Bartz, E.; Gershtein, Y.; Halkiadakis, E.; Kyriacou, S.; Lath, A.; Nash, K.; Osherson, M.; Schnetzer, S.; Stone, R.; Walker, M.; Malik, S.; Norberg, S.; Ramirez Vargas, J. E.; Alyari, M.; Dolen, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Kharchilava, A.; Nguyen, D.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; McDermott, K.; Mirman, N.; Rinkevicius, A.; Ryd, A.; Salvati, E.; Skinnari, L.; Soffi, L.; Tao, Z.; Thom, J.; Tucker, J.; Zientek, M.; Akgün, B.; Ecklund, K. M.; Kilpatrick, M.; Nussbaum, T.; Zabel, J.; Betchart, B.; Covarelli, R.; Demina, R.; Hindrichs, O.; Petrillo, G.; Eusebi, R.; Patel, R.; Perloff, A.; Ulmer, K. A.; Delannoy, A. G.; D'Angelo, P.; Johns, W.

2018-03-01

A new CMS Tracker is under development for operation at the High Luminosity LHC from 2026 onwards. It includes an outer tracker based on dedicated modules that will reconstruct short track segments, called stubs, using spatially coincident clusters in two closely spaced silicon sensor layers. These modules allow the rejection of low transverse momentum track hits and reduce the data volume before transmission to the first level trigger. The inclusion of tracking information in the trigger decision is essential to limit the first level trigger accept rate. A customized front-end readout chip, the CMS Binary Chip (CBC), containing stub finding logic has been designed for this purpose. A prototype module, equipped with the CBC chip, has been constructed and operated for the first time in a 4 GeemVem/emc positron beam at DESY. The behaviour of the stub finding was studied for different angles of beam incidence on a module, which allows an estimate of the sensitivity to transverse momentum within the future CMS detector. A sharp transverse momentum threshold around 2 emVem/emc was demonstrated, which meets the requirement to reject a large fraction of low momentum tracks present in the LHC environment on-detector. This is the first realistic demonstration of a silicon tracking module that is able to select data, based on the particle's transverse momentum, for use in a first level trigger at the LHC . The results from this test are described here.

Method and apparatus for detecting gem-polyhalogenated hydrocarbons

DOEpatents

Anderson, deceased, William G.; Anderson, legal representative, Johanna S.

1990-01-01

A method and optrode for detecting gem polyhalogenated hydrocarbons in a sample fluid based on a single phase Fujiwara reaction as provided. The method comprises contacting a reaction mixture with a sample fluid which contains the gem-polyhalogenated hydrocarbons. The reaction mixture comprises an aqueous solution of pyridine or derivative thereof and a hindered nitrogen base. Upon contact a fluorescent and/or chromgenic reaction product forms whose fluorescence and/or absorbance is related to the concentration of gem-polyhalogenated hydrocarbons in the sample fluid.

Synthesis of GEMS from Shock-accelerated Crystalline Dust in Superbubbles: Model and Predictions

NASA Technical Reports Server (NTRS)

Westphal, Andrew J.; Bradley, John P.

2005-01-01

GEMS (Glass Embedded with Metals and Sulfides) are highly enigmatic yet common components of anhydrous IDPs. We have recently proposed a model of GEMS formation from shock-accelerated crystalline dust in superbubbles[1] which explains the three most perplexing properties of GEMS: pseudomorphism[2], their chemistry[3], and their size range. In this Abstract, we briefly review the main points of the model, and suggest tests that will either prove or rule out this hypothesis.

Two new sources of reactive gaseous mercury in the free troposphere

NASA Astrophysics Data System (ADS)

Timonen, H.; Ambrose, J. L.; Jaffe, D. A.

2012-11-01

Mercury (Hg) is a neurotoxin that bioaccumulates in the food chain. Mercury is emitted to the atmosphere primarily in its elemental form, which has a long lifetime allowing global transport. It is known that atmospheric oxidation of gaseous elemental mercury (GEM) generates reactive gaseous mercury (RGM) which plays an important role in the atmospheric mercury cycle by enhancing the rate of mercury deposition to ecosystems. However, the primary GEM oxidants, and the sources and chemical composition of RGM are poorly known. Using speciated mercury measurements conducted at the Mt. Bachelor Observatory since 2005 we present two previously unidentified sources of RGM to the free troposphere (FT). Firstly, we observed elevated RGM concentrations, large RGM/GEM-ratios, and anti-correlation between RGM and GEM during Asian long-rang transport events, demonstrating that RGM is formed from GEM by in-situ oxidation in some anthropogenic pollution plumes in the FT. During the Asian pollution events the measured RGM/GEM-ratios reached peak values, up to ~0.20, which are significantly larger than ratios typically measured (RGM/GEM < 0.05) in the Asian source region. Secondly, we observed very high RGM levels - the highest reported in the FT - in clean air masses that were processed upwind of Mt. Bachelor Observatory over the Pacific Ocean. The high RGM concentrations (up to 700 pg m-3), high RGM/GEM-ratios (up to 1), and very low ozone levels during these events provide the first observational evidence indicating significant GEM oxidation in the lower FT. The identification of these processes changes our conceptual understanding of the formation and distribution of oxidized Hg in the global atmosphere.

Genetic consultation embedded in a gynecologic oncology clinic improves compliance with guideline-based care.

PubMed

Senter, Leigha; O'Malley, David M; Backes, Floor J; Copeland, Larry J; Fowler, Jeffery M; Salani, Ritu; Cohn, David E

2017-10-01

Analyze the impact of embedding genetic counseling services in gynecologic oncology on clinician referral and patient uptake of cancer genetics services. Data were reviewed for a total of 737 newly diagnosed epithelial ovarian cancer patients seen in gynecologic oncology at a large academic medical center including 401 from 11/2011-7/2014 (a time when cancer genetics services were provided as an off-site consultation). These data were compared to data from 8/2014-9/2016 (n=336), when the model changed to the genetics embedded model (GEM), incorporating a cancer genetic counselor on-site in the gynecologic oncology clinic. A statistically significant difference in proportion of patients referred pre- and post-GEM was observed (21% vs. 44%, p<0.0001). Pre-GEM, only 38% of referred patients were actually scheduled for genetics consultation and post-GEM 82% were scheduled (p<0.00001). The difference in the time from referral to scheduling in genetics was also statistically significant (3.92months pre-GEM vs. 0.79months post-GEM, p<0.00001) as was the time from referral to completion of genetics consultation (2.52months pre-GEM vs. 1.67months post-GEM, p<0.01). Twenty-five percent of patients referred post GEM were seen by the genetic counselor on the same day as the referral. Providing cancer genetics services on-site in gynecologic oncology and modifying the process by which patients are referred and scheduled significantly increases referral to cancer genetics and timely completion of genetics consultation, improving compliance with guideline-based care. Practice changes are critical given the impact of genetic test results on treatment and familial cancer risks. Copyright © 2017 Elsevier Inc. All rights reserved.

SONTRAC: A solar neutron track chamber detector

NASA Technical Reports Server (NTRS)

Frye, G. M., Jr.; Jenkins, T. L.; Owens, A.

1985-01-01

The recent detection on the solar maximum mission (SMM) satellite of high energy neutrons emitted during large solar flares has provided renewed incentive to design a neutron detector which has the sensitivity, energy resolution, and time resolution to measure the neutron time and energy spectra with sufficient precision to improve our understanding of the basic flare processes. Over the past two decades a variety of neutron detectors has been flown to measure the atmospheric neutron intensity above 10 MeV and to search for solar neutrons. The SONTRAC (Solar Neutron Track Chamber) detector, a new type of neutron detector which utilizes n-p scattering and has a sensitivity 1-3 orders of magnitude greater than previous instruments in the 20-200 MeV range is described. The energy resolution is 1% for neutron kinetic energy, T sub n 50 MeV. When used with a coded aperture mask at 50 m (as would be possible on the space station) an angular resolution of approx. 4 arc sec could be achieved, thereby locating the sites of high energy nuclear interactions with an angular precision comparable to the existing x-ray experiments on SMM. The scintillation chamber is investigated as a track chamber for high energy physics, either by using arrays of scintillating optical fibers or by optical imaging of particle trajectories in a block of scintillator.

Indoor concentration of radon, thoron and their progeny around granite regions in the state of Karnataka, India.

PubMed

Sannappa, J; Ningappa, C

2014-03-01

An extensive studies on the indoor activity concentrations of thoron, radon and their progeny in the granite region in the state of Karnataka, India, has been carried out since, 2007 in the scope of a lung cancer epidemiological study using solid-state nuclear track detector-based double-chamber dosemeters (LR-115, type II plastic track detector). Seventy-four dwellings of different types were selected for the measurement. The dosemeters containing SSNTD detectors were fixed 2 m above the floor. After an exposure time of 3 months (90 d), films were etched to reveal tracks. From the track density, the concentrations of radon and thoron were evaluated. The value of the indoor concentration of thoron and radon in the study area varies from 16 to 170 Bq m(-3) and 18 to 300 Bq m(-3) with medians of 66 and 82.3 Bq m(-3), respectively, and that of their progeny varies from 1.8 to 24 mWL with a median of 3.6 mWL and 1.6 to 19.6 mWL, respectively. The concentrations of indoor thoron, radon and their progeny and their equivalent effective doses are discussed.

The < ln A > study with the Muon tracking detector in the KASCADE-Grande experiment - comparison of hadronic interaction models

NASA Astrophysics Data System (ADS)

Łuczak, P.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Curcio, C.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

2015-08-01

With the KASCADE-Grande Muon Tracking Detector it was possible to measure with high accuracy directions of EAS muons with energy above 0.8 GeV and up to 700 m distance from the shower centre. Reconstructed muon tracks allow investigation of muon pseudorapidity (η) distributions. These distributions are nearly identical to the pseudorapidity distributions of their parent mesons produced in hadronic interactions. Comparison of the η distributions from measured and simulated showers can be used to test the quality of the high energy hadronic interaction models. The pseudorapidity distributions reflect the longitudinal development of EAS and, as such, are sensitive to the mass of the cosmic ray primary particles. With various parameters of the η distribution, obtained from the Muon Tracking Detector data, it is possible to calculate the average logarithm of mass of the primary cosmic ray particles. The results of the < ln A > analysis in the primary energy range 1016 eV-1017 eV with the 1st quartile and the mean value of the distributions will be presented for the QGSJet-II-2, QGSJet-II-4, EPOS 1.99 and EPOS LHC models in combination with the FLUKA model.

CR-39 track detector calibration for H, He, and C ions from 0.1-0.5 MeV up to 5 MeV for laser-induced nuclear fusion product identification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baccou, C., E-mail: claire.baccou@polytechnique.edu; Yahia, V.; Labaune, C.

Laser-accelerated ion beams can be used in many applications and, especially, to initiate nuclear reactions out of thermal equilibrium. We have experimentally studied aneutronic fusion reactions induced by protons accelerated by the Target Normal Sheath Acceleration mechanism, colliding with a boron target. Such experiments require a rigorous method to identify the reaction products (alpha particles) collected in detectors among a few other ion species such as protons or carbon ions, for example. CR-39 track detectors are widely used because they are mostly sensitive to ions and their efficiency is near 100%. We present a complete calibration of CR-39 track detectormore » for protons, alpha particles, and carbon ions. We give measurements of their track diameters for energy ranging from hundreds of keV to a few MeV and for etching times between 1 and 8 h. We used these results to identify alpha particles in our experiments on proton-boron fusion reactions initiated by laser-accelerated protons. We show that their number clearly increases when the boron fuel is preformed in a plasma state.« less

LDEF Experiment P0006 Linear Energy Transfer Spectrum Measurement (LETSME) quick look report

NASA Technical Reports Server (NTRS)

1990-01-01

A preliminary analysis of the various passive radiation detector materials included in the P0006 LETSME experiment flown on LDEF (Long Duration Exposure Facility) is presented. It consists of four tasks: (1) readout and analysis of thermoluminescent detectors (TLD); (2) readout and analysis of fission foil/mica detectors; (3) readout and analysis of (6)LiF/CR-39 detectors; and (4) preliminary processing and readout of CR-39 and polycarbonate plastic nuclear track detectors (PNTD).

Chopper-stabilized phase detector

NASA Technical Reports Server (NTRS)

Hopkins, P. M.

1978-01-01

Phase-detector circuit for binary-tracking loops and other binary-data acquisition systems minimizes effects of drift, gain imbalance, and voltage offset in detector circuitry. Input signal passes simultaneously through two channels where it is mixed with early and late codes that are alternately switched between channels. Code switching is synchronized with polarity switching of detector output of each channel so that each channel uses each detector for half time. Net result is that dc offset errors are canceled, and effect of gain imbalance is simply change in sensitivity.

Silicon pixel-detector R&D for CLIC

NASA Astrophysics Data System (ADS)

Nürnberg, A.

2016-11-01

The physics aims at the future CLIC high-energy linear e+e- collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of a few μm, ultra-low mass (~ 0.2%X0 per layer for the vertex region and ~ 1%X0 per layer for the outer tracker), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ~ 10 ns time stamping capabilities. A highly granular all-silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints. For the vertex-detector region, hybrid pixel detectors with small pitch (25 μm) and analog readout are explored. For the outer tracking region, both hybrid concepts and fully integrated CMOS sensors are under consideration. The feasibility of ultra-thin sensor layers is validated with Timepix3 readout ASICs bump bonded to active edge planar sensors with 50 μm to 150 μm thickness. Prototypes of CLICpix readout ASICs implemented in 6525 nm CMOS technology with 25 μm pixel pitch have been produced. Hybridisation concepts have been developed for interconnecting these chips either through capacitive coupling to active HV-CMOS sensors or through bump-bonding to planar sensors. Recent R&D achievements include results from beam tests with all types of hybrid assemblies. Simulations based on Geant4 and TCAD are used to validate the experimental results and to assess and optimise the performance of various detector designs.

Representing Misalignments of the STAR Geometry Model using AgML

NASA Astrophysics Data System (ADS)

Webb, Jason C.; Lauret, Jérôme; Perevotchikov, Victor; Smirnov, Dmitri; Van Buren, Gene

2017-10-01

The STAR Heavy Flavor Tracker (HFT) was designed to provide high-precision tracking for the identification of charmed hadron decays in heavy-ion collisions at RHIC. It consists of three independently mounted subsystems, providing four precision measurements along the track trajectory, with the goal of pointing decay daughters back to vertices displaced by less than 100 microns from the primary event vertex. The ultimate efficiency and resolution of the physics analysis will be driven by the quality of the simulation and reconstruction of events in heavy-ion collisions. In particular, it is important that the geometry model properly accounts for the relative misalignments of the HFT subsystems, along with the alignment of the HFT relative to STARs primary tracking detector, the Time Projection Chamber (TPC). The Abstract Geometry Modeling Language (AgML) provides a single description of the STAR geometry, generating both our simulation (GEANT 3) and reconstruction geometries (ROOT). AgML implements an ideal detector model, while misalignments are stored separately in database tables. These have historically been applied at the hit level. Simulated detector hits are projected from their ideal position along the track’s trajectory, until they intersect the misaligned detector volume, where the struck detector element is calculated for hit digitization. This scheme has worked well as hit errors have been negligible compared with the size of sensitive volumes. The precision and complexity of the HFT detector require us to apply misalignments to the detector volumes themselves. In this paper we summarize the extension of the AgML language and support libraries to enable the static misalignment of our reconstruction and simulation geometries, discussing the design goals, limitations and path to full misalignment support in ROOT/VMC-based simulation.

Development of a high efficiency personal/environmental radon dosimeter using polycarbonate detectors.

PubMed

Taheri, M; Jafarizadeh, M; Baradaran, S; Zainali, Gh

2006-12-01

Passive radon dosimeters, based on alpha particle etched track detectors, are widely used for the assessment of radon exposure. These methods are often applied in radon dosimetry for long periods of time. In this research work, we have developed a highly efficient method of personal/environmental radon dosimetry that is based upon the detection of alpha particles from radon daughters, (218)Po and (214)Po, using a polycarbonate detector (PC). The radon daughters are collected on the filter surface by passing a fixed flow of air through it and the PC detector, placed at a specified distance from the filter, is simultaneously exposed to alpha particles. After exposure, the latent tracks on the detector are made to appear by means of an electrochemical etching process; these are proportional to the radon dose. The air flow rate and the detector-filter distance are the major factors that can affect the performance of the dosimeter. The results obtained in our experimental investigations have shown that a distance of 1.5 cm between the detector and the filter, an absorber layer of Al with a thickness of 12 microm and an air flow rate of 4 l min(-1) offer the best design parameters for a high efficiency radon dosimeter. Then, the designed dosimeter was calibrated against different values of radon exposures and the obtained sensitivity was found to be 2.1 (tracks cm(-2)) (kBq h m(-3))(-1). The most important advantages of this method are that it is reliable, fast and convenient when used for radon dose assessment. In this paper, the optimized parameters of the dosimeter structure and its calibration procedure are presented and discussed.

Gamma-ray momentum reconstruction from Compton electron trajectories by filtered back-projection

DOE PAGES

Haefner, A.; Gunter, D.; Plimley, B.; ...

2014-11-03

Gamma-ray imaging utilizing Compton scattering has traditionally relied on measuring coincident gamma-ray interactions to map directional information of the source distribution. This coincidence requirement makes it an inherently inefficient process. We present an approach to gamma-ray reconstruction from Compton scattering that requires only a single electron tracking detector, thus removing the coincidence requirement. From the Compton scattered electron momentum distribution, our algorithm analytically computes the incident photon's correlated direction and energy distributions. Because this method maps the source energy and location, it is useful in applications, where prior information about the source distribution is unknown. We demonstrate this method withmore » electron tracks measured in a scientific Si charge coupled device. While this method was demonstrated with electron tracks in a Si-based detector, it is applicable to any detector that can measure electron direction and energy, or equivalently the electron momentum. For example, it can increase the sensitivity to obtain energy and direction in gas-based systems that suffer from limited efficiency.« less

Development of Resistive Electrode Gas Electron Multiplier (RE-GEM)

NASA Technical Reports Server (NTRS)

Yoshikawa, A.; Tamagawa, T.; Iwahashi, T.; Asami, F.; Takeuchi, Y.; Hayato, A.; Hamagaki, H.; Gunji, T.; Akimoto, R.; Nukariya, A.;

Gaseous Elemental Mercury (GEM) Emissions from Snow Surfaces in Northern New York

PubMed Central

Maxwell, J. Alexander; Holsen, Thomas M.; Mondal, Sumona

2013-01-01

Snow surface-to-air exchange of gaseous elemental mercury (GEM) was measured using a modified Teflon fluorinated ethylene propylene (FEP) dynamic flux chamber (DFC) in a remote, open site in Potsdam, New York. Sampling was conducted during the winter months of 2011. The inlet and outlet of the DFC were coupled with a Tekran Model 2537A mercury (Hg) vapor analyzer using a Tekran Model 1110 two port synchronized sampler. The surface GEM flux ranged from −4.47 ng m−2 hr−1 to 9.89 ng m−2 hr−1. For most sample periods, daytime GEM flux was strongly correlated with solar radiation. The average nighttime GEM flux was slightly negative and was not well correlated with any of the measured meteorological variables. Preliminary, empirical models were developed to estimate GEM emissions from snow surfaces in northern New York. These models suggest that most, if not all, of the Hg deposited with and to snow is reemitted to the atmosphere. PMID:23874951

Divergent Mechanistic Routes for the Formation of gem-Dimethyl Groups in the Biosynthesis of Complex Polyketides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poust, S; Phelan, RM; Deng, K

The gem-dimethyl groups in polyketide-derived natural products add steric bulk and, accordingly, lend increased stability to medicinal compounds, however, our ability to rationally incorporate this functional group in modified natural products is limited. In order to characterize the mechanism of gem-dimethyl group formation, with a goal toward engineering of novel compounds containing this moiety, the gem-dimethyl group producing polyketide synthase (PKS) modules of yersiniabactin and epothilone were characterized using mass spectrometry. The work demonstrated, contrary to the canonical understanding of reaction order in PKSs, that methylation can precede condensation in gem-dimethyl group producing PKS modules. Experiments showed that both PKSsmore » are able to use dimethylmalonyl acyl carrier protein (ACP) as an extender unit. Interestingly, for epothilone module8, use of dimethylmalonyl-ACP appeared to be the sole route to form a gem-dimethylated product, while the yersiniabactin PKS could methylate before or after ketosynthase condensation.« less

Gaseous elemental mercury (GEM) emissions from snow surfaces in northern New York.

PubMed

Maxwell, J Alexander; Holsen, Thomas M; Mondal, Sumona

2013-01-01

Snow surface-to-air exchange of gaseous elemental mercury (GEM) was measured using a modified Teflon fluorinated ethylene propylene (FEP) dynamic flux chamber (DFC) in a remote, open site in Potsdam, New York. Sampling was conducted during the winter months of 2011. The inlet and outlet of the DFC were coupled with a Tekran Model 2537A mercury (Hg) vapor analyzer using a Tekran Model 1110 two port synchronized sampler. The surface GEM flux ranged from -4.47 ng m(-2) hr(-1) to 9.89 ng m(-2) hr(-1). For most sample periods, daytime GEM flux was strongly correlated with solar radiation. The average nighttime GEM flux was slightly negative and was not well correlated with any of the measured meteorological variables. Preliminary, empirical models were developed to estimate GEM emissions from snow surfaces in northern New York. These models suggest that most, if not all, of the Hg deposited with and to snow is reemitted to the atmosphere.

Atmospheric Neutrinos in Soudan 2

NASA Astrophysics Data System (ADS)

Goodman, M.; Soudan 2 Collaboration

2001-08-01

Neutrino interactions recorded in a 5.1 fiducial kiloton-year exposure of the Soudan-2 iron tracking calorimeter are analyzed for effects of neutrino oscillations. Using contained single track and single shower events, we update our measurement of the atmospheric / ratio-of-ratios and find . Assuming this anomalously low R-value is the result of flavor disappearance viat o oscillation, we select samples of charged current events which offer good resolution, event-by-event, for Ä reconstruction. Oscillation-weighted Monte Carlo events are fitted to these data events using a ¾ function summed over bins of log´Ä µ. The region allowed in the (× Ò¾ ¾ , ¡Ñ¾) plane at 90% CL is obtained using the Feldman-Cousins procedure: 1 DETECTOR; DATA EXPOSURE The Soudan-2 experiment will soon (July 2001) be completing the taking of data using its fine-grained iron tracking calorimeter of total mass 963 tons. This detector images nonrelativistic as well as relativistic charged particles produced in atmospheric neutrino reactions. It has operated underground at a depth of 2100 meters-water-equivalent on level 27 of the Soudan Mine State Park in northern Minnesota. The calorimeter's modular design enabled data-taking to commence in April 1989 when the detector was one quarter of its full size; assembly of the detector was completed during 1993. Data-taking continued with 85% live time, even though dynamite blasting has been underway nearby for the MINOS cavern excavation since Summer 1999. The total data exposure will be 5.8fiducial kiloton-years (kTy). Results presented here are based upon a 5.1 kTy exposure. The tracking calorimeter operates as a slow-drift (0.6 cm/ s) time projection chamber. Its tracking elements are meterlong plastic drift tubes which are placed into the corruga-

Position sensitive detection of neutrons in high radiation background field.

PubMed

Vavrik, D; Jakubek, J; Pospisil, S; Vacik, J

2014-01-01

We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e(-) radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm(2)) spectroscopic Timepix detector adapted for neutron detection utilizing very thin (10)B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10(-4).

Commissioning of the ATLAS Muon Spectrometer with cosmic rays

DOE PAGES

Aad, G; Abbott, B; Abdallah, J; ...

2010-12-01

The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. Themore » results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions. © 2010 CERN for the benefit of the ATLAS collaboration.« less

Position sensitive detection of neutrons in high radiation background field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vavrik, D., E-mail: vavrik@itam.cas.cz; Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prosecka 76, 190 00 Prague 9; Jakubek, J.

We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e{sup −} radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm{sup 2}) spectroscopic Timepix detector adapted for neutron detection utilizing very thin {sup 10}B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane)more » and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10{sup −4}.« less

The large-area hybrid-optics RICH detector for the CLAS12 spectrometer

DOE PAGES

Mirazita, M.; Angelini, G.; Balossino, I.; ...

2017-01-16

A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadronization and hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and densely packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forwardmore » tracks) or after two mirror reflections (large angle tracks). Finally, the preliminary results of individual detector component tests and of the prototype performance at test-beams are reported here.« less

Aircraft Observations of Mercury over the US: The Nomadss Experiment

NASA Astrophysics Data System (ADS)

Jaffe, D. A.; Ambrose, J. L., II; Gratz, L.; Jaegle, L.; Shah, V.; Selin, N. E.; Song, S.; Giang, A.

2014-12-01

The Nitrogen, Oxidants, Mercury, and Aerosol Distributions, Sources and Sinks (NOMADSS) experiment took place in the summer of 2013. This is one of the first airborne experiments to focus on the sources and chemistry of Hg in the atmosphere. The experiment flew 19 research flights on the NCAR C-130 aircraft, based out of Smyrna, TN. The primary Hg goals for NOMADSS were to constrain emissions of Hg over the U.S. and quantify the distribution and chemistry of Gaseous Elemental Mercury (GEM) and Reactive Mercury (RM) in the troposphere. We measured speciated Hg on the C-130 using the UW-Detector of Oxidized HG species (UW-DOHGS). This instrument has been developed over several years and tested/calibrated with several HgX2 compounds and other compounds to examine possible interferences. In its current configuration, the instrument quantitatively measures HgX2 compounds (HgCl2 and HgBr2) with no interference from O3. During NOMADSS, flight planning was facilitated by use of the NASA GEOS-5 system, which provided forecasts for many relevant tracers. Post-mission analyses are being conducted using the GEOS-Chem Hg model. This provides a key tool to compare current estimates of Hg sources and distribution with aircraft observations. We are using the NOMADSS data for several types of analyses: GEM emissions and concentrations in power plant plumes and downwind of urban centers; Presence of RM in relatively high concentration in several free tropospheric locations; Evaluation and interpretation of the data using the GEOS-Chem Hg model. While there are a number of important results from NOMADSS, the most striking is the high concentrations of RM GOM in some regions of the upper troposphere, significantly higher than calculated by the standard GEOS-Chem simulation. We believe this is most likely due to halogen oxidation. These results suggest higher halogen concentrations or faster oxidation of GEM and thus a substantial rethinking of Hg oxidation in the global atmosphere.

The Effects of HSP27 on Gemcitabine-Resistant Pancreatic Cancer Cell Line Through Snail.

PubMed

Zhang, Song; Zhang, Xiao-qi; Huang, Shu-ling; Chen, Min; Shen, Shan-shan; Ding, Xi-wei; Lv, Ying; Zou, Xiao-ping

2015-10-01

To evaluate the regulation mechanism of heat shock protein 27 (HSP27) on gemcitabine (GEM) resistance of pancreatic cancer cell. The expression vectors pEGFP-C1-HSP27 and the vectors of MicroRNA targeting Snail were introduced into GEM-sensitive pancreatic cancer SW1990 cells, and the vectors of small hairpin RNA targeting HSP27 were transfected into SW1990 and GEM-resistant SW1990/GEM cells. The expressions of HSP27, p-HSP27 (Ser82), Snail, ERCC1, and E-cadherin were evaluated by Western blotting. The sensitivity of transfected cells to GEM was detected by CCK-8 assay and Annexin V-FITC apoptosis assay. As compared to SW1990, SW1990/GEM showed significantly increased expressions of HSP27, p-HSP27, Snail and ERCC1 with decreased expression of E-cadherin. By increasing HSP27 expression, we found increase of Snail and ERCC1 with reduction of E-cadherin expressions, while reduction of HSP27 expression caused reduction of Snail and ERCC1 but increase of E-cadherin expressions. Downregulation of Snail resulted in the reduction of ERCC1 expression and increase of E-cadherin. Furthermore, downregulation of HSP27 or snail caused increased GEM sensitivity of pancreatic cancer cells, and upregulation of HSP27 showed the opposite results. There is an inverse correlation between HSP27 expression and GEM sensitivity of SW1990 cells, which might be realized by regulating E-cadherin and ERCC1 expressions through Snail.

Fission foil detector calibrations with high energy protons

NASA Technical Reports Server (NTRS)

Benton, E. V.; Frank, A. L.

1995-01-01

Fission foil detectors (FFD's) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD's, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutron fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.

Contributions of natural and anthropogenic sources to ambient ammonia in the Athabasca Oil Sands and north-western Canada

NASA Astrophysics Data System (ADS)

Whaley, Cynthia H.; Makar, Paul A.; Shephard, Mark W.; Zhang, Leiming; Zhang, Junhua; Zheng, Qiong; Akingunola, Ayodeji; Wentworth, Gregory R.; Murphy, Jennifer G.; Kharol, Shailesh K.; Cady-Pereira, Karen E.

2018-02-01

Atmospheric ammonia (NH3) is a short-lived pollutant that plays an important role in aerosol chemistry and nitrogen deposition. Dominant NH3 emissions are from agriculture and forest fires, both of which are increasing globally. Even remote regions with relatively low ambient NH3 concentrations, such as northern Alberta and Saskatchewan in northern Canada, may be of interest because of industrial oil sands emissions and a sensitive ecological system. A previous attempt to model NH3 in the region showed a substantial negative bias compared to satellite and aircraft observations. Known missing sources of NH3 in the model were re-emission of NH3 from plants and soils (bidirectional flux) and forest fire emissions, but the relative impact of these sources on NH3 concentrations was unknown. Here we have used a research version of the high-resolution air quality forecasting model, GEM-MACH, to quantify the relative impacts of semi-natural (bidirectional flux of NH3 and forest fire emissions) and direct anthropogenic (oil sand operations, combustion of fossil fuels, and agriculture) sources on ammonia volume mixing ratios, both at the surface and aloft, with a focus on the Athabasca Oil Sands region during a measurement-intensive campaign in the summer of 2013. The addition of fires and bidirectional flux to GEM-MACH has improved the model bias, slope, and correlation coefficients relative to ground, aircraft, and satellite NH3 measurements significantly.By running the GEM-MACH-Bidi model in three configurations and calculating their differences, we find that averaged over Alberta and Saskatchewan during this time period an average of 23.1 % of surface NH3 came from direct anthropogenic sources, 56.6 % (or 1.24 ppbv) from bidirectional flux (re-emission from plants and soils), and 20.3 % (or 0.42 ppbv) from forest fires. In the NH3 total column, an average of 19.5 % came from direct anthropogenic sources, 50.0 % from bidirectional flux, and 30.5 % from forest fires. The addition of bidirectional flux and fire emissions caused the overall average net deposition of NHx across the domain to be increased by 24.5 %. Note that forest fires are very episodic and their contributions will vary significantly for different time periods and regions.This study is the first use of the bidirectional flux scheme in GEM-MACH, which could be generalized for other volatile or semi-volatile species. It is also the first time CrIS (Cross-track Infrared Sounder) satellite observations of NH3 have been used for model evaluation, and the first use of fire emissions in GEM-MACH at 2.5 km resolution.

Cold Fronts in RegCM/HadGEM simulations over South America

NASA Astrophysics Data System (ADS)

Pampuch, Luana; Marcos de Jesus, Eduardo; Porfírio da Rocha, Rosmeri; Ambrizzi, Tércio

2017-04-01

Cold front is one of the most important systems that contribute for precipitation over South America. The representation of this system in climate models is important for a better representation of the precipitation. The Regional Climate Model RegCM is widely used for climate studies in South America, being important to understand how this model represents the cold fronts. A climatology (from 1979-2004) of the number of cold fronts in each season for RegCM4 simulations over South America CORDEX domain nested in HadGEM2-ES. The simulated climatology was compared with ERA-Interim reanalysis cold fronts climatology over the South America and adjacent South Atlantic Ocean. The cold fronts tracking for the model and the reanalysis were performed using an objective methodology based on decrease of air temperature in 925hPa, shift of meridional wind in 925hPa from northern to southern quadrant and increased in sea level pressure. The main differences were observed on summer and winter. On summer the model overestimate the number of cold fronts over southeastern South America and adjacent Atlantic Ocean; and underestimate it over central-south Argentina and Atlantic Ocean. On winter, the signs were opposite of that summer. On autumn and spring the differences were smaller and occurs mainly over all South Atlantic and north Argentina.

An artificial retina processor for track reconstruction at the LHC crossing rate

DOE PAGES

Bedeschi, F.; Cenci, R.; Marino, P.; ...

2017-11-23

The goal of the INFN-RETINA R&D project is to develop and implement a computational methodology that allows to reconstruct events with a large number (> 100) of charged-particle tracks in pixel and silicon strip detectors at 40 MHz, thus matching the requirements for processing LHC events at the full bunch-crossing frequency. Our approach relies on a parallel pattern-recognition algorithm, dubbed artificial retina, inspired by the early stages of image processing by the brain. In order to demonstrate that a track-processing system based on this algorithm is feasible, we built a sizable prototype of a tracking processor tuned to 3 000more » patterns, based on already existing readout boards equipped with Altera Stratix III FPGAs. The detailed geometry and charged-particle activity of a large tracking detector currently in operation are used to assess its performances. Here, we report on the test results with such a prototype.« less

Accelerating CR-39 Track Detector Processing by Utilizing UV

NASA Astrophysics Data System (ADS)

Sparling, Jonathan; Padalino, Stephen; McLean, James; Sangster, Craig; Regan, Sean

2017-10-01

The use of CR-39 plastic as a Solid State Nuclear Track Detector is an effective technique for obtaining data in high energy particle experiments including inertial confinement fusion. To reveal particle tracks after irradiation, CR-39 is chemically etched in NaOH at 80°C, producing micron-scale signal pits at the nuclear track sites. It has been shown that illuminating CR-39 with UV light prior to etching increases bulk and track etch rates, especially when combined with elevated temperature. Spectroscopic analysis for amorphous solids has helped identify which UV wavelengths are most effective at enhancing etch rates. Absorption peaks found in the near infrared range provide for efficient sample heating, and may allow targeting cooperative IR-UV chemistry. Avoiding UV induced noise can be achieved through variations in absorption depths with wavelength. Vacuum drying and water absorption tests allow measurement of the resulting variation of bulk etch rate with depth. Funded in part by the NSF and an Department of Energy Grant through the Lab of Laser Energetics.

An artificial retina processor for track reconstruction at the LHC crossing rate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bedeschi, F.; Cenci, R.; Marino, P.

The goal of the INFN-RETINA R&D project is to develop and implement a computational methodology that allows to reconstruct events with a large number (> 100) of charged-particle tracks in pixel and silicon strip detectors at 40 MHz, thus matching the requirements for processing LHC events at the full bunch-crossing frequency. Our approach relies on a parallel pattern-recognition algorithm, dubbed artificial retina, inspired by the early stages of image processing by the brain. In order to demonstrate that a track-processing system based on this algorithm is feasible, we built a sizable prototype of a tracking processor tuned to 3 000more » patterns, based on already existing readout boards equipped with Altera Stratix III FPGAs. The detailed geometry and charged-particle activity of a large tracking detector currently in operation are used to assess its performances. Here, we report on the test results with such a prototype.« less

Directional Track Selection Technique in CR39 SSNTD for lowyield reaction experiments

NASA Astrophysics Data System (ADS)

Ingenito, Francesco; Andreoli, Pierluigi; Batani, Dimitri; Bonasera, Aldo; Boutoux, Guillaume; Burgy, Frederic; Cipriani, Mattia; Consoli, Fabrizio; Cristofari, Giuseppe; De Angelis, Riccardo; Di Giorgio, Giorgio; Ducret, Jean Eric; Giulietti, Danilo; Jakubowska, Katarzyna

2018-01-01

There is a great interest in the study of p-11B aneutronic nuclear fusion reactions, both for energy production and for determination of fusion cross-sections at low energies. In this context we performed experiments at CELIA in which energetic protons, accelerated by the laser ECLIPSE, were directed toward a solid Boron target. Because of the small cross-sections at these energies the number of expected reactions is low. CR39 Solid-State Nuclear Track Detectors (SSNTD) were used to detect the alpha particles produced. Because of the low expected yield, it is difficult to discriminate the tracks due to true fusion products from those due to natural background in the CR39. To this purpose we developed a methodology of particle recognition according to their direction with respect to the detector normal, able to determine the position of their source. We applied this to the specific experiment geometry, so to select from all the tracks those due to particles coming from the region of interaction between accelerated protons and solid boron target. This technique can be of great help on the analysis of SSNTD in experiments with low yield reactions, but can be also generally applied to any experiment where particles reach the track detector with known directions, and for example to improve the detection limit of particle spectrometers using CR39.

Search for disappearing tracks as a signature of new long-lived particles in proton-proton collisions at $$\\sqrt{s} =$$ 13 TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sirunyan, Albert M; et al.

A search is presented for long-lived charged particles that decay within the CMS detector and produce the signature of a disappearing track. A disappearing track is an isolated track with missing hits in the outer layers of the silicon tracker, little or no energy in associated calorimeter deposits, and no associated hits in the muon detectors. This search uses data collected with the CMS detector in 2015 and 2016 from proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC, corresponding to an integrated luminosity of 38.4 fbmore » $$^{-1}$$. The results of the search are interpreted in the context of the anomaly-mediated supersymmetry breaking model. The data are consistent with the background-only hypothesis. Limits are set on the product of the cross section for direct production of charginos and their branching fraction to a neutralino and a pion, as a function of the chargino mass and lifetime. At 95% confidence level, charginos with masses below 715 (695) GeV are excluded for a lifetime of 3 (7) ns, as are charginos with lifetimes from 0.5 to 60 ns for a mass of 505 GeV. These are the most stringent limits using a disappearing track signature on this signal model for chargino lifetimes above $$\\approx$$0.7 ns.« less

Characterization of single α-tracks by photoresist detection and AFM analysis-focus on biomedical science and technology

NASA Astrophysics Data System (ADS)

Falzone, Nadia; Myhra, Sverre; Chakalova, Radka; Hill, Mark A.; Thomson, James; Vallis, Katherine A.

2013-11-01

The interactions between energetic ions and biological and/or organic target materials have recently attracted theoretical and experimental attention, due to their implications for detector and device technologies, and for therapeutic applications. Most of the attention has focused on detection of the primary ionization tracks, and their effects, while recoil target atom tracks remain largely unexplored. Detection of tracks by a negative tone photoresist (SU-8), followed by standard development, in combination with analysis by atomic force microscopy, shows that both primary and recoil tracks are revealed as conical spikes, and can be characterized at high spatial resolution. The methodology has the potential to provide detailed information about single impact events, which may lead to more effective and informative detector technologies and advanced therapeutic procedures. In comparison with current characterization methods the advantageous features include: greater spatial resolution by an order of magnitude (20 nm) detection of single primary and associated recoil tracks; increased range of fluence (to 2.5 × 109 cm-2) sensitivity to impacts at grazing angle incidence; and better definition of the lateral interaction volume in target materials.

Detectors (5/5)

ScienceCinema

None

2018-02-01

This lecture will serve as an introduction to particle detectors and detection techniques. In the first lecture, a historic overview of particle detector development will be given. In the second lecture, some basic techniques and concepts for particle detection will be discussed. In the third lecture, the interaction of particles with matter, the basis of particle detection, will be presented. The fourth and fifth lectures will discuss different detector types used for particle tracking, energy measurement and particle identification.

Detectors (4/5)

ScienceCinema

None

2018-05-14

This lecture will serve as an introduction to particle detectors and detection techniques. In the first lecture, a historic overview of particle detector development will be given. In the second lecture, some basic techniques and concepts for particle detection will be discussed. In the third lecture, the interaction of particles with matter, the basis of particle detection, will be presented. The fourth and fifth lectures will discuss different detector types used for particle tracking, energy measurement and particle identification.

Muon trackers for imaging a nuclear reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kume, N.; Miyadera, H.; Morris, C. L.

A detector system for assessing damage to the cores of the Fukushima Daiichi nuclear reactors by using cosmic-ray muon tomography was developed. Furthermore, the system consists of a pair of drift-tube tracking detectors of 7.2× 7.2-m 2 area. In each muon tracker there consists 6 x-layer and 6 y-layer drift-tube detectors. Each tracker is capable of measuring muon tracks with 12 mrad angular resolutions, and is capable of operating under 50-μ Sv/h radiation environment by removing gamma induced background with a novel time-coincidence logic. An estimated resolution to observe nuclear fuel debris at Fukushima Daiichi is 0.3 m when themore » core is imaged from outside the reactor building.« less

Muon trackers for imaging a nuclear reactor

DOE PAGES

Kume, N.; Miyadera, H.; Morris, C. L.; ...

2016-09-21

A detector system for assessing damage to the cores of the Fukushima Daiichi nuclear reactors by using cosmic-ray muon tomography was developed. Furthermore, the system consists of a pair of drift-tube tracking detectors of 7.2× 7.2-m 2 area. In each muon tracker there consists 6 x-layer and 6 y-layer drift-tube detectors. Each tracker is capable of measuring muon tracks with 12 mrad angular resolutions, and is capable of operating under 50-μ Sv/h radiation environment by removing gamma induced background with a novel time-coincidence logic. An estimated resolution to observe nuclear fuel debris at Fukushima Daiichi is 0.3 m when themore » core is imaged from outside the reactor building.« less