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Sample records for alice time-of-flight detector

  1. Particle identification with the ALICE Time-Of-Flight detector at the LHC

    NASA Astrophysics Data System (ADS)

    Alici, A.

    2014-12-01

    High performance Particle Identification system (PID) is a distinguishing characteristic of the ALICE experiment at the CERN Large Hadron Collider (LHC). Charged particles in the intermediate momentum range are identified in ALICE by the Time-Of-Flight (TOF) detector. The TOF exploits the Multi-gap Resistive Plate Chamber (MRPC) technology, capable of an intrinsic time resolution at the level of few tens of ps with an overall efficiency close to 100% and a large operation plateau. The full system is made of 1593 MRPC chambers with a total area of 141 m2, covering the pseudorapidity interval [-0.9,+0.9] and the full azimuthal angle. The ALICE TOF system has shown very stable operation during the first 3 years of collisions at the LHC. In this paper a summary of the system performance as well as main results with data from collisions will be reported.

  2. The MRPC-based ALICE time-of-flight detector: Status andperformance

    NASA Astrophysics Data System (ADS)

    Alici, A.; ALICE Collaboration

    2013-04-01

    The large time-of-flight (TOF) array is one of the main detectors devoted to charged hadron identification in the mid-rapidity region of the ALICE experiment at the LHC. It allows separation among pions, kaons and protons up to a few GeV/c, covering the full azimuthal angle and -0.9<η<0.9. The TOF exploits the innovative MRPC technology capable of an intrinsic time resolution better than 50 ps with an efficiency close to 100% and a large operational plateau; the full array consists of 1593 MRPCs covering a cylindrical surface of 141 m2. The TOF detector has been efficiently taking data since the first pp collisions recorded in ALICE in December 2009. In this report, the status of the TOF detector and the performance achieved for both pp and Pb-Pb collisions aredescribed.

  3. Status and performance of the ALICE MRPC-based Time-Of-Flight detector

    NASA Astrophysics Data System (ADS)

    Alici, A.

    2012-10-01

    ALICE is the dedicated heavy-ion experiment at the CERN LHC. One of the main detectors devoted to charged hadron identification in the ALICE central barrel is a large Time-Of-Flight (TOF) array; it allows separation among pions, kaons and protons up to a few GeV/c, covering the full azimuthal angle and -0.9 < η < 0.9. The very good performance required for such a system has been achieved by means of the Multigap Resistive Plate Chamber (MRPC) whose intrinsic time resolution is better than 50 ps with an overall efficiency close to 100% and a large operational plateau; the full array consists of 1593 MRPCs covering a cylindrical surface of 141 m2. In this report, the status of the TOF detector and the performance achieved during the 2010 and 2011 data taking periods are reported together with selected physics results obtained with pp and Pb-Pb collisions.

  4. The CDF Time of Flight Detector

    SciTech Connect

    S. Cabrera et al.

    2004-01-06

    A new Time of Flight (TOF) detector based on scintillator bars with fine-mesh photomultipliers at both ends has been in operation since 2001 in the CDF experiment. With a design resolution of 100 ps, the TOF can provide separation between K{sup +-} and {pi}{sup +-} in p{bar p} collisions at the 2{omega} level for low momentum, which enhances b flavor tagging capabilities. Because of its very fast response, the TOF is an excellent triggering device, and it is used to trigger on highly ionizing particles, multiple minimum ionizing particles and cosmic rays. Particle identification is achieved by comparing the time-of-flight of the particle measured by the TOF to the time expected for a given mass hypothesis. In order to obtain the resolution necessary for particle ID, optimal calibrations are critical. This paper describes the TOF detector, its calibration procedure, the achieved resolution, the long term operation performances and some of the first results from data analysis using this detector.

  5. The TORCH time-of-flight detector

    NASA Astrophysics Data System (ADS)

    Harnew, N.; Brook, N.; Castillo García, L.; Cussans, D.; Föhl, K.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Piedigrossi, D.; Rademacker, J.; Ros Garcia, A.; van Dijk, M.

    2016-07-01

    The TORCH time-of-flight detector is being developed to provide particle identification between 2 and 10 GeV/c momentum over a flight distance of 10 m. TORCH is designed for large-area coverage, up to 30 m2, and has a DIRC-like construction. The goal is to achieve a 15 ps time-of-flight resolution per incident particle by combining arrival times from multiple Cherenkov photons produced within quartz radiator plates of 10 mm thickness. A four-year R&D programme is underway with an industrial partner (Photek, UK) to produce 53×53 mm2 Micro-Channel Plate (MCP) detectors for the TORCH application. The MCP-PMT will provide a timing accuracy of 40 ps per photon and it will have a lifetime of up to at least 5 Ccm-2 of integrated anode charge by utilizing an Atomic Layer Deposition (ALD) coating. The MCP will be read out using charge division with customised electronics incorporating the NINO chipset. Laboratory results on prototype MCPs are presented. The construction of a prototype TORCH module and its simulated performance are also described.

  6. Recipes for high resolution time-of-flight detectors

    SciTech Connect

    Anz, S.J. |; Felter, T.E.; Hess, B.V.; Daley, R.S.; Roberts, M.L.; Williams, R.S.

    1995-01-01

    The authors discuss the dynamics, construction, implementation and benefits of a time-of-flight (TOF) detector with count rates an order of magnitude higher and resolution three to four times better than that obtainable with a surface barrier detector. The propose use of design criteria for a time-of-flight detector is outlined, and the determination of a TOF detector`s total relative timing error and how this value determines the mass resolution are illustrated using a graphical analysis. They present simulation and experimental examples employing light ions and discuss advantages and pitfalls of medium-energy heavy ion TOF spectrometry.

  7. Tests and calibration of NIF neutron time of flight detectors.

    PubMed

    Ali, Z A; Glebov, V Yu; Cruz, M; Duffy, T; Stoeckl, C; Roberts, S; Sangster, T C; Tommasini, R; Throop, A; Moran, M; Dauffy, L; Horsefield, C

    2008-10-01

    The National Ignition Facility (NIF) neutron time of flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD(*) implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 1x10(9) to 2x10(19). The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 and 20 m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE). Operational tests of the NTOF detectors were performed on several facilities including the OMEGA laser at LLE and the Titan laser at Lawrence Livermore National Laboratory. Neutron calibrations were carried out on the OMEGA laser. Results of the NTOF detector tests and calibration will be presented.

  8. The diamond time of flight detector of the TOTEM experiment

    NASA Astrophysics Data System (ADS)

    Berretti, Mirko

    2017-02-01

    This contribution describes the design and the performance of a novel timing detector developed by the TOTEM Collaboration. The detector will be installed inside the TOTEM Roman Pots (RPs) and will measure the Time-Of-Flight (TOF) of the protons produced in the central diffractive (CD) interactions at the LHC. In particular, the measurement of the proton TOF allows the determination of the vertex longitudinal position where the protons are produced, thus allowing the protons association with one of the vertices reconstructed by the CMS detectors. The TOF detector is based on single crystal CVD (scCVD) diamond plates and it is designed in order to measure the protons TOF with 50 ps time resolution. To achieve this performance, a dedicated fast and low noise electronics for the signal amplification has been developed. Indeed, while diamond sensors have lower noise and faster signals than silicon sensors, the amount of charge released in the medium is lower. The digitization of the diamond signal is performed sampling the waveform at 10 GSa/s with the SAMPIC chip. The performance of the first TOF detector installed in the LHC in November 2015 will be reported. An overview of the clock distribution system and of the control system which interfaces the timing detectors to the experiment DAQ is finally given.

  9. Time-of-flight detector for heavy ion backscattering spectrometry

    SciTech Connect

    Knapp, J.A.; Banks, J.C.; Doyle, B.L.

    1994-04-01

    This report describes the results of a two-year laboratory directed research and development project to explore advanced concepts in Heavy Ion Backscattering Spectrometry (HIBS), undertaken with the goal of extending the sensitivity of this relatively new technique to levels unattainable by any other existing trace element surface analysis. Improvements in sensitivity are required for the application of HIBS to contamination control in the microelectronics industry. Tools with sensitivity approaching 10{sup 8} atoms/cm{sup 2} are expected to be essential for enabling advanced IC production by the year 2000. During the project the authors developed a new analysis chamber with channeling goniometer and a prototype time-of-flight detector with a demonstrated sensitivity of {approximately} 5 {times} 10{sup 8} atoms/cm{sup 2} for Au on Si and {approximately} 5 {times} 10{sup 10} for Fe, and sufficient mass resolution to separate contributions from Fe and Cu.

  10. AD, the ALICE diffractive detector

    NASA Astrophysics Data System (ADS)

    Tello, Abraham Villatoro

    2017-03-01

    ALICE is one of the four large experiments at the CERN Large Hadron Collider (LHC). As a complement to its Heavy-Ion physics program, ALICE started during Run 1 of LHC an extensive program dedicated to the study of proton-proton diffractive processes. In order to optimize its trigger efficiencies and purities in selecting diffractive events, the ALICE Collaboration installed a very forward AD detector during the Long Shut Down 1 of LHC. This new forward detector system consists of two stations made of two layers of scintillator pads, one station on each side of the interaction point. With this upgrade, ALICE has substantially increased its forward physics coverage, including the double rapidity gap based selection of central production, as well as the measurements of inclusive diffractive cross sections.

  11. The ALICE Pixel Detector

    NASA Astrophysics Data System (ADS)

    Mercado-Perez, Jorge

    2002-07-01

    The present document is a brief summary of the performed activities during the 2001 Summer Student Programme at CERN under the Scientific Summer at Foreign Laboratories Program organized by the Particles and Fields Division of the Mexican Physical Society (Sociedad Mexicana de Fisica). In this case, the activities were related with the ALICE Pixel Group of the EP-AIT Division, under the supervision of Jeroen van Hunen, research fellow in this group. First, I give an introduction and overview to the ALICE experiment; followed by a description of wafer probing. A brief summary of the test beam that we had from July 13th to July 25th is given as well.

  12. Design, construction, characterization and use of a detector to measure time of flight of cosmic rays

    NASA Astrophysics Data System (ADS)

    Araujo, A. C.; Félix, J.

    2016-10-01

    In the study of cosmic rays, measurements of time of flight and momentum have been used to identify incident particles from its physical properties, like mass. In this poster we present the design, construction, characterization, and operation of a detector to measure time of flight of cosmic rays. The device is comprised of three plates of plastic scintillator arranged in vertical straight line, they are coupled to one photomultiplier tube. The analogical output has been connected to a data acquisition system to obtain the number of digital pulses per millisecond. We present preliminary results.

  13. Precision electronics for a system of custom MCPs in the TORCH Time of Flight detector

    NASA Astrophysics Data System (ADS)

    Gao, R.; Brook, N.; Castillo García, L.; Conneely, T.; Cussans, D.; Föhl, K.; Forty, R.; Frei, C.; Gys, T.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; Ros García, A.; Van Dijk, M.

    2017-03-01

    The TORCH detector will provide charged particle pi/K/p identification up to 10 GeV/c, combining Time-of-Flight and Cherenkov techniques to achieve a timing resolution of 70 ps for single photons. Based on a scalable design, a Time-of-Flight electronics readout system has been developed to instrument a novel customized 512-channel Micro Channel Plate (MCP) device. A Gigabit Ethernet-based readout scheme that operates the TORCH demonstration unit consisting of ten such MCPs will be reported. The trigger and clock distribution will also be discussed.

  14. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA.

    PubMed

    Glebov, V Yu; Forrest, C; Knauer, J P; Pruyne, A; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C; Caggiano, J A; Carman, M L; Clancy, T J; Hatarik, R; McNaney, J; Zaitseva, N P

    2012-10-01

    A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D-D and D-T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented.

  15. Detector response in time-of-flight mass spectrometry at high pulse repetition frequencies

    NASA Technical Reports Server (NTRS)

    Gulcicek, Erol E.; Boyle, James G.

    1993-01-01

    Dead time effects in chevron configured dual microchannel plates (MCPs) are investigated. Response times are determined experimentally for one chevron-configured dual MCP-type detector and two discrete dynode-type electron multipliers with 16 and 23 resistively divided stages. All of these detectors are found to be suitable for time-of-flight mass spectrometry (TOF MS), yielding 3-6-ns (FWHM) response times triggered on a single ion pulse. It is concluded that, unless there are viable solutions to overcome dead time disadvantages for continuous dynode detectors, suitable discrete dynode detectors for TOF MS appear to have a significant advantage for high repetition rate operation.

  16. Calibration of time of flight detectors using laser-driven neutron source

    SciTech Connect

    Mirfayzi, S. R.; Kar, S. Ahmed, H.; Green, A.; Alejo, A.; Jung, D.; Krygier, A. G.; Freeman, R. R.; Clarke, R.; Fuchs, J.; Vassura, L.; Kleinschmidt, A.; Roth, M.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Zepf, M.; Borghesi, M.

    2015-07-15

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  17. Calibration of time of flight detectors using laser-driven neutron source

    NASA Astrophysics Data System (ADS)

    Mirfayzi, S. R.; Kar, S.; Ahmed, H.; Krygier, A. G.; Green, A.; Alejo, A.; Clarke, R.; Freeman, R. R.; Fuchs, J.; Jung, D.; Kleinschmidt, A.; Morrison, J. T.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.

    2015-07-01

    Calibration of three scintillators (EJ232Q, BC422Q, and EJ410) in a time-of-flight arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub-MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors is shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  18. A high performance Time-of-Flight detector applied to isochronous mass measurement at CSRe

    NASA Astrophysics Data System (ADS)

    Mei, Bo; Tu, Xiaolin; Wang, Meng; Xu, Hushan; Mao, Ruishi; Hu, Zhengguo; Ma, Xinwen; Yuan, Youjin; Zhang, Xueying; Geng, Peng; Shuai, Peng; Zang, Yongdong; Tang, Shuwen; Ma, Peng; Lu, Wan; Yan, Xinshuai; Xia, Jiawen; Xiao, Guoqing; Guo, Zhongyan; Zhang, Hongbin; Yue, Ke

    2010-12-01

    A high performance Time-of-Flight detector has been designed and constructed for isochronous mass spectrometry at the experimental Cooler Storage Ring (CSRe). The detector has been successfully used in an experiment to measure the masses of the N≈ Z≈33 nuclides near the proton drip-line. Of particular interest is the mass of 65As. A maximum detection efficiency of 70% and a time resolution of 118±8 ps (FWHM) have been achieved in the experiment. The dependence of detection efficiency and signal average pulse height (APH) on atomic number Z has been studied. The potential of APH for Z identification has been discussed.

  19. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA.

    PubMed

    Glebov, V Yu; Forrest, C J; Marshall, K L; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C

    2014-11-01

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D2 neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

  20. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA

    SciTech Connect

    Glebov, V. Yu. Forrest, C. J.; Marshall, K. L.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C.

    2014-11-15

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D{sub 2} neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

  1. TORCH - Cherenkov and Time-of-Flight PID Detector for the LHCb Upgrade at CERN

    NASA Astrophysics Data System (ADS)

    Föhl, K.; Brook, N.; Castillo García, L.; Conneely, T.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Milnes, J.; Piedigrossi, D.; Rademacker, J.; Ros Garcì a, A.; van Dijk, M.

    2016-05-01

    TORCH is a large-area precision time-of-flight detector, based on Cherenkov light production and propagation in a quartz radiator plate, which is read out at its edges. TORCH is proposed for the LHCb experiment at CERN to provide positive particle identification for kaons, and is currently in the Research-and-Development phase. A brief overview of the micro-channel plate photon sensor development, the custom-made electronics, and an introduction to the current test beam activities is given. Optical readout solutions are presented for the potential use of BaBar DIRC bar boxes as part of the TORCH configuration in LHCb.

  2. A silicon photomultiplier readout for time of flight neutron spectroscopy with {gamma}-ray detectors

    SciTech Connect

    Pietropaolo, A.; Gorini, G.; Festa, G.; Andreani, C.; De Pascale, M. P.; Reali, E.; Grazzi, F.; Schooneveld, E. M.

    2009-09-15

    The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of {gamma}-detection based on the new device.

  3. A silicon photomultiplier readout for time of flight neutron spectroscopy with gamma-ray detectors.

    PubMed

    Pietropaolo, A; Gorini, G; Festa, G; Andreani, C; De Pascale, M P; Reali, E; Grazzi, F; Schooneveld, E M

    2009-09-01

    The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of gamma-detection based on the new device.

  4. The CDFII time-of-flight detector and impact on beauty flavor tagging

    SciTech Connect

    C. Grozis et al.

    2002-12-03

    Following the successful RunI from 1992 to 1996, the CDF detector has undergone a major upgrade [1] for the RunII which begun in March 2001. The approval for the addition of a Time-of-Flight detector was granted in January 1999. The installation of the TOF detector was completed in August 2001 and its data has been included in the CDFII readout since then. The primary physics motivation for TOF is to complement and enhance the particle identification capability provided by the central drift chamber (COT) since it distinguishes K{sup {+-}} and {pi}{sup {+-}} in the momentum region of their cross-over in dE=dX. With an expected time-of-flight resolution of 100 ps, the TOF system will be capable of identifying charged kaons from pions by their flight time difference with at least two standard deviation separation up to kaon momenta of 1.6 GeV/c. Such an addition results in an enhancement of the b flavor identification power, crucial to improve the statistical precision in CP violation and B{sub s} mixing measurements.

  5. Time of flight elastic recoil detection analysis with a position sensitive detector

    SciTech Connect

    Siketic, Zdravko; Radovic, Iva Bogdanovic; Jaksic, Milko; Skukan, Natko

    2010-03-15

    A position sensitive detection system based on the microchannel plate detector has been constructed and installed at the existing time of flight (TOF) spectrometer in order to perform a kinematic correction and improve the surface time/depth resolution of elastic recoil detection analysis (ERDA) system. The position resolution of the detector has been tested for different types of ions and anode voltages. TOF spectra of recoiled O ions from SiO{sub 2} and F from CaF{sub 2} were collected in coincidence with position sensitive detector signal. Kinematic correction of TOF spectra improved surface time/depth resolution by {approx}20% for our system; however even higher improvements could be obtained in larger solid angle TOF-ERDA systems.

  6. Optimization of a multi-ring detector for Ps time of flight measurements

    NASA Astrophysics Data System (ADS)

    Di Noto, L.; Benetti, M.; Mariazzi, S.; Dalla Betta, G.-F.; Brusa, R. S.

    2013-06-01

    We have designed a multi-ring detector (MRD) based on Bismuth Germanate (BGO) crystals, coupled to Silicon PhotoMultipliers (SiPM) for measuring the Ps time of flight (TOF). The set-up geometry was optimized by Monte Carlo simulations to take into account at different Ps velocities: (i) the background noise due to backscattered positrons, (ii) the crosstalk between adjacent detectors, (iii) the lifetime of Ps decay. Three parameters were defined to evaluate the different configurations and a figure of merit was obtained. This allows the choice of the best set up configuration for measuring Ps emitted with a particular energy range, optimizing the signal to noise ratio and keeping the acquisition time acceptable.

  7. Barrel time-of-flight detector for the PANDA experiment at FAIR

    NASA Astrophysics Data System (ADS)

    Gruber, L.; Brunner, S. E.; Marton, J.; Orth, H.; Suzuki, K.

    2016-07-01

    The barrel time-of-flight detector for the PANDA experiment at FAIR is foreseen as a Scintillator Tile (SciTil) Hodoscope based on several thousand small plastic scintillator tiles read-out with directly attached Silicon Photomultipliers (SiPMs). The main tasks of the system are an accurate determination of the time origin of particle tracks to avoid event mixing at high collision rates, relative time-of-flight measurements as well as particle identification in the low momentum regime. The main requirements are the use of a minimum material amount and a time resolution of σ < 100 ps. We have performed extensive optimization studies and prototype tests to prove the feasibility of the SciTil design and finalize the R&D phase. In a 2.7 GeV/c proton beam at Forschungszentrum Jülich a time resolution of about 80 ps has been achieved using SiPMs from KETEK and Hamamatsu with an active area of 3 × 3mm2. Employing the Digital Photon Counter from Philips a time resolution of about 30 ps has been reached.

  8. Determination of the event collision time with the ALICE detector at the LHC

    NASA Astrophysics Data System (ADS)

    Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; An, M.; Andrei, C.; Andrews, H. A.; Andronic, A.; Anguelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Anwar, R.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Beltran, L. G. E.; Belyaev, V.; Bencedi, G.; Beole, S.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Boldizsár, L.; Bombara, M.; Bonora, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buhler, P.; Buitron, S. A. I.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Caines, H.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, S.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crkovská, J.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Souza, R. D.; Deisting, A.; Deloff, A.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Di Ruzza, B.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Duggal, A. K.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erhardt, F.; Espagnon, B.; Esumi, S.; Eulisse, G.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Francisco, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gajdosova, K.; Gallio, M.; Galvan, C. D.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Garg, K.; Garg, P.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Gay Ducati, M. B.; Germain, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Graham, K. L.; Greiner, L.; Grelli, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grion, N.; Gronefeld, J. M.; Grosse-Oetringhaus, J. F.; Grosso, R.; Gruber, L.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Guzman, I. B.; Haake, R.; Hadjidakis, C.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, F.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Hladky, J.; Horak, D.; Hosokawa, R.; Hristov, P.; Hughes, C.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Ippolitov, M.; Irfan, M.; Isakov, V.; Islam, M. S.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacak, B.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jahnke, C.; Jakubowska, M. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Mohisin Khan, M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Khatun, A.; Khuntia, A.; Kileng, B.; Kim, D. W.; Kim, D. J.; Kim, D.; Kim, H.; Kim, J. S.; Kim, J.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kundu, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lapidus, K.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lazaridis, L.; Lea, R.; Leardini, L.; Lee, S.; Lehas, F.; Lehner, S.; Lehrbach, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Llope, W.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lupi, M.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzilli, M.; Mazzoni, M. A.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Mhlanga, S.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Mishra, T.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montes, E.; Moreira De Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Münning, K.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Myers, C. J.; Naik, B.; Nair, R.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Natal da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Negrao De Oliveira, R. A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Ohlson, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pacik, V.; Pagano, D.; Pagano, P.; Paić, G.; Pal, S. K.; Palni, P.; Pan, J.; Pandey, A. K.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, J.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Peng, X.; Pereira Da Costa, H.; Peresunko, D.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Poppenborg, H.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Pozdniakov, V.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Rana, D. B.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Ratza, V.; Ravasenga, I.; Read, K. F.; Redlich, K.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rodríguez Cahuantzi, M.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sandoval, A.; Sano, M.; Sarkar, D.; Sarkar, N.; Sarma, P.; Sas, M. H. P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schmidt, M.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sett, P.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Sozzi, F.; Spiriti, E.; Sputowska, I.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Suzuki, K.; Swain, S.; Szabo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thakur, D.; Thomas, D.; Tieulent, R.; Tikhonov, A.; Timmins, A. R.; Toia, A.; Tripathy, S.; Trogolo, S.; Trombetta, G.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Umaka, E. N.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vázquez Doce, O.; Vechernin, V.; Veen, A. M.; Velure, A.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Vértesi, R.; Vickovic, L.; Vigolo, S.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Virgili, T.; Vislavicius, V.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Voscek, D.; Vranic, D.; Vrláková, J.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Willems, G. A.; Williams, M. C. S.; Windelband, B.; Winn, M.; Witt, W. E.; Yalcin, S.; Yang, P.; Yano, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yoon, J. H.; Yurchenko, V.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zmeskal, J.

    2017-02-01

    Particle identification is an important feature of the ALICE detector at the LHC. In particular, for particle identification via the time-of-flight technique, the precise determination of the event collision time represents an important ingredient of the quality of the measurement. In this paper, the different methods used for such a measurement in ALICE by means of the T0 and the TOF detectors are reviewed. Efficiencies, resolution and the improvement of the particle identification separation power of the methods used are presented for the different LHC colliding systems (pp, p-Pb and Pb-Pb) during the first period of data taking of LHC (RUN 1).

  9. Diamond detectors for time-of-flight measurements in laser-generated plasmas

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Margarone, D.; Milani, E.; Verona-Rinati, G.; Prestopino, G.; Tuvè, C.; Potenza, R.; Láska, L.; Krása, J.; Ullschmied, J.

    CVD mono-crystalline diamond thin films deposited on a doped diamond and aluminum backing were employed as detectors of the radiation emitted from the laser-generated plasma. Laser-matter interactions were obtained by the use of an Nd:Yag repetitive laser at INFN-LNS in Catania operating at 1010 W/cm2 pulse intensity, and a high-power iodine PALS laser in Prague operating at 1015 W/cm2 pulse intensity. Plasmas were obtained by ablating Al, Ta, Au, and CF2 bulk targets. Plasma characterization was carried out using diamond detectors and ion collectors placed at different distances and angles in relation to the position of the ablated target. Photons, electrons, and ions hitting the sensible volume of the detector generate electronhole pairs (loosing 13 eV for a pair), resulting in an arising of the voltage signal at the device electrodes, which is proportional to the deposited energy. Diamond detectors can measure UV, X-rays, electrons, and ions. The time-of-flight (TOF) technique was exploited to separate photon, electron, and particle contributions. Because of the high gap of the diamond band structure (5.48 eV), the detectors are blind to visible and IR light from the plasma, which results in very low background current. The TOF diamond spectra were compared with traditional ion collector spectra using the experimental data obtained from the experiments conducted at the Catania and Prague laboratories. The results indicate that the ion energy resolution of the employed diamond detectors is high and that the fast electrons can be detected from a deconvolution procedure applied to the fast photo-peak. Information about the mean energy of soft X-rays could be obtained by analyzing the fast contribute of the spectra acquired by using different absorber films.

  10. CVD Diamond Detectors for Current Mode Neutron Time-of-Flight Spectroscopy at OMEGA/NIF

    SciTech Connect

    Schmid, G J; Friensehner, A F; Glebov, V Y; Hargrove, D R; Hatchett, S P; Izumi, N; Lerche, R A; Phillips, T W; Sangster, T C; Sibernagel, C; Stoeckl, C

    2001-06-19

    As part of a laser fusion diagnostic development program, we have performed pulsed neutron and pulsed laser tests of a CVD diamond detector manufactured from DIAFILM, a commercial grade of CVD diamond. The laser tests were performed at the short pulse UV laser at Bechtel Nevada in Livermore, CA. The pulsed neutrons were provided by DT capsule implosions at the OMEGA laser fusion facility in Rochester, NY. From these tests, we have determined the impulse response to be 250 ps fwhm for an applied E-field of 500 V/mm. Additionally, we have determined the sensitivity to be 2.8 mA/W at 500 V/mm and 4.5 mA/W at 1000 V/mm (2 to 6x times higher than reported values for natural Type IIa diamond). These detector characteristics allow us to conceive of a neutron time-of-flight current mode spectrometer based on CVD diamond. Such an instrument would sit inside the laser fusion target chamber close to TCC, and would record neutron spectra fast enough such that backscattered neutrons and y rays from the target chamber wall would not be a concern. However, the data we have taken show that the Electromagnetic Pulse (EMP) noise could be a limiting factor in performance. Determining the degree to which this noise can be shielded will be an important subject of future tests.

  11. The TORCH time-of-flight detector for particle identification and photon vertex association

    NASA Astrophysics Data System (ADS)

    Castillo García, L.; Brook, N.; Cussans, D.; Föhl, K.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Piedigrossi, D.; Rademacker, J.; Ros García, A.; van Dijk, M.

    2017-02-01

    TORCH (Time Of internally Reflected CHerenkov light) is a novel time-of-flight detector, designed to provide π /K/p particle identification up to 0~ 1 GeV/c momentum and beyond. To achieve this, a time resolution of ~ 15 ps combining information from 0~ 3 detected photons is required over a 10 m flight path. Large areas can be covered with TORCH, nominally up to 30 m2. One such application is for the LHCb experiment, to complement the particle identification capabilities of its RICH detectors. TORCH has a DIRC-like construction with 10 mm-thick synthetic amorphous fused-silica plates as a radiator. Cherenkov photons propagate by total internal reflection to the plate edges and there are focussed onto an array of position-sensitive photodetectors. Custom-built micro-channel plate photo-multipliers (MCP-PMTs) are being developed in collaboration with industry to provide the lifetime, granularity and time resolution to meet the TORCH specifications. In the present paper, laboratory tests of the MCP-PMTs developed for TORCH and its readout electronics are presented. Test beam measurements of a prototype TORCH detector in a low-momentum mixed beam of pions and protons are highlighted. Time resolutions for individual photons approaching 100 ps is achieved, after correction for dispersion effects in the quartz medium. In addition to the particle identification capabilities, the high-precision timing information that TORCH provides could be used at the high-luminosity LHC to associate high-energy photons with the correct primary interaction vertex amongst the many expected.

  12. The Silicon Pixel Detector for ALICE Experiment

    SciTech Connect

    Fabris, D.; Bombonati, C.; Dima, R.; Lunardon, M.; Moretto, S.; Pepato, A.; Bohus, L. Sajo; Scarlassara, F.; Segato, G.; Shen, D.; Turrisi, R.; Viesti, G.; Anelli, G.; Boccardi, A.; Burns, M.; Campbell, M.; Ceresa, S.; Conrad, J.; Kluge, A.; Kral, M.

    2007-10-26

    The Inner Tracking System (ITS) of the ALICE experiment is made of position sensitive detectors which have to operate in a region where the track density may be as high as 50 tracks/cm{sup 2}. To handle such densities detectors with high precision and granularity are mandatory. The Silicon Pixel Detector (SPD), the innermost part of the ITS, has been designed to provide tracking information close to primary interaction point. The assembly of the entire SPD has been completed.

  13. A fast preamplifier concept for SiPM-based time-of-flight PET detectors

    NASA Astrophysics Data System (ADS)

    Huizenga, J.; Seifert, S.; Schreuder, F.; van Dam, H. T.; Dendooven, P.; Löhner, H.; Vinke, R.; Schaart, D. R.

    2012-12-01

    Silicon photomultipliers (SiPMs) offer high gain and fast response to light, making them interesting for fast timing applications such as time-of-flight (TOF) PET. To fully exploit the potential of these photosensors, dedicated preamplifiers that do not deteriorate the rise time and signal-to-noise ratio are crucial. Challenges include the high sensor capacitance, typically >300 pF for a 3 mm×3 mm SiPM sensor, as well as oscillation issues. Here we present a preamplifier concept based on low noise, high speed transistors, designed for optimum timing performance. The input stage consists of a transimpedance common-base amplifier with a very low input impedance even at high frequencies, which assures a good linearity and avoids that the high detector capacitance affects the amplifier bandwidth. The amplifier has a fast timing output as well as a 'slow' energy output optimized for determining the total charge content of the pulse. The rise time of the amplifier is about 300 ps. The measured coincidence resolving time (CRT) for 511 keV photon pairs using the amplifiers in combination with 3 mm×3 mm SiPMs (Hamamatsu MPPC-S10362-33-050C) coupled to 3 mm×3 mm×5 mm LaBr3:Ce and LYSO:Ce crystals equals 95 ps FWHM and 138 ps FWHM, respectively.

  14. CVD Diamond Detectors for Current Mode Neutron Time-of-Flight Spectroscopy at OMEGA/NIF

    SciTech Connect

    G. J. Schmid; V. Yu. Glebov; A. V. Friensehner; D. R. Hargrove; S. P. Hatchett; N. Izumi; R. A. Lerche; T. W. Phillips; T. C. Sangster; C. Silbernagel; C. Stoecki

    2001-07-01

    We have performed pulsed neutron and pulsed laser tests of a CVD diamond detector manufactured from DIAFILM, a commercial grade of CVD diamond. The laser tests were performed at the short pulse UV laser at Bechtel Nevada in Livermore, CA. The pulsed neutrons were provided by DT capsule implosions at the OMEGA laser fusion facility in Rochester, NY. From these tests, we have determined the impulse response to be 250 ps fwhm for an applied E-field of 500 V/mm. Additionally, we have determined the sensitivity to be 2.4 mA/W at 500 V/mm and 4.0 mA/W at 1000 V/mm. These values are approximately 2 to 5x times higher than those reported for natural Type IIa diamond at similar E-field and thickness (1mm). These characteristics allow us to conceive of a neutron time-of-flight current mode spectrometer based on CVD diamond. Such an instrument would sit inside the laser fusion target chamber close to target chamber center (TCC), and would record neutron spectra fast enough such that backscattered neutrons and x-rays from the target chamber wall would not be a concern. The acquired neutron spectra could then be used to extract DD fuel areal density from the downscattered secondary to secondary ratio.

  15. A gas ionisation detector in the axial (Bragg) geometry used for the time-of-flight elastic recoil detection analysis

    SciTech Connect

    Siketić, Zdravko; Skukan, Natko; Bogdanović Radović, Iva

    2015-08-15

    In this paper, time-of-flight elastic recoil detection analysis spectrometer with a newly constructed gas ionization detector for energy detection is presented. The detector is designed in the axial (Bragg) geometry with a 3 × 3 array of 50 nm thick Si{sub 3}N{sub 4} membranes as an entrance window. 40 mbar isobutane gas was sufficient to stop a 30 MeV primary iodine beam as well as all recoils in the detector volume. Spectrometer and detector performances were determined showing significant improvement in the mass and energy resolution, respectively, comparing to the spectrometer with a standard silicon particle detector for an energy measurement.

  16. A gas ionisation detector in the axial (Bragg) geometry used for the time-of-flight elastic recoil detection analysis.

    PubMed

    Siketić, Zdravko; Skukan, Natko; Bogdanović Radović, Iva

    2015-08-01

    In this paper, time-of-flight elastic recoil detection analysis spectrometer with a newly constructed gas ionization detector for energy detection is presented. The detector is designed in the axial (Bragg) geometry with a 3 × 3 array of 50 nm thick Si3N4 membranes as an entrance window. 40 mbar isobutane gas was sufficient to stop a 30 MeV primary iodine beam as well as all recoils in the detector volume. Spectrometer and detector performances were determined showing significant improvement in the mass and energy resolution, respectively, comparing to the spectrometer with a standard silicon particle detector for an energy measurement.

  17. Operational experience with the ALICE pixel detector

    NASA Astrophysics Data System (ADS)

    Mastroserio, A.

    2017-01-01

    The Silicon Pixel Detector (SPD) constitutes the two innermost layers of the Inner Tracking System of the ALICE experiment and it is the closest detector to the interaction point. As a vertex detector, it has the unique feature of generating a trigger signal that contributes to the L0 trigger of the ALICE experiment. The SPD started collecting data since the very first pp collisions at LHC in 2009 and since then it has taken part in all pp, Pb-Pb and p-Pb data taking campaigns. This contribution will present the main features of the SPD, the detector performance and the operational experience, including calibration and optimization activities from Run 1 to Run 2.

  18. Charge injectors of ALICE Silicon Drift Detector

    NASA Astrophysics Data System (ADS)

    Rashevsky, A.; Batigne, G.; Beole, S.; Coli, S.; Crescio, E.; Deremigis, P.; Giraudo, G.; Mazza, G.; Prino, F.; Riccati, L.; Rivetti, A.; Toscano, L.; Tosello, F.; Vacchi, A.; Wheadon, R.; Zampa, G.

    2007-03-01

    Large area, 7.25×8.76 cm2, Silicon Drift Detector (SDD) has been developed for the ALICE experiment at CERN [A. Vacchi, et al., Nucl. Instr. and Meth. A 306 (1991) 187; A. Rashevsky, et al., Nucl. Instr. and Meth. A 461 (2001) 133-138; A. Rashevsky, et al., Nucl. Instr. and Meth. A 485 (2002) 54; P. Burger, C. Piemonte, A. Rashevsky, A. Roncastri, A. Vacchi, INFN/TC-02/07; C. Piemonte, A. Rashevsky, INFN/TC-02/08; C. Piemonte, A. Rashevsky, D. Nouais, INFN/TC-00/04. C. Piemonte, A. Rashevsky, A. Vacchi, ALICE-INT-2002-15, 2002; Inner Tracking System, CERN/LHCC, June 1999]. SDDs form two out of six cylindrical layers of the ALICE inner tracking system. The 260 high-quality SDDs needed to equip these two layers have been selected. One of the detector design elements devoted to allow controlled operating conditions is the on-board arrays of point-like charge injectors [D. Nouais, et al., CERN-ALICE-PUB-99-31; V. Bonvicini, et al., Il Nuovo Cimento 112AN (1-2) (1999) 137-146]. In the case of an SDD they are essential to trace, with the required frequency and precision, the changes in drift velocity induced by temperature variations. In order to ensure operating stability during the 10 years of the ALICE experiment the bias scheme of the charge injectors exploits the electrical properties not only of a detector itself, but also those of the cables mounted onto it, thus constituting a module. Computer simulations of the equivalent circuit revealed a significant improvement of the injection efficiency. Subsequent experimental tests of the first assembled modules confirmed the predicted performances. We report the layout of the charge injectors integrated in the ALICE SDD, as well as test results.

  19. Construction of the optical part of a time-of-flight detector prototype for the AFP detector.

    PubMed

    Nozka, L; Adamczyk, L; Avoni, G; Brandt, A; Buglewicz, P; Cavallaro, E; Chiodini, G; Chytka, L; Ciesla, K; Davis, P M; Dyndal, M; Grinstein, S; Hamal, P; Hrabovsky, M; Janas, K; Jirakova, K; Kocian, M; Komarek, T; Korcyl, K; Lange, J; Mandat, D; Michalek, V; Paz, I Lopez; Northacker, D; Rijssenbeek, M; Seabra, L; Schovanek, P; Staszewski, R; Swierska, P; Sykora, T

    2016-11-28

    We present the construction of the optical part of the ToF (time-of-flight) subdetector prototype for the AFP (ATLAS Forward Proton) detector. The ToF detector in conjunction with a 3D silicon pixel tracker will tag and measure protons originating in central exclusive interactions p + p → p + X + p, where the two outgoing protons are scattered in the very forward directions. The ToF is required to reduce so-called pileup backgrounds that arise from multiple proton interactions in the same bunch crossing at high luminosity. The background can fake the signal of interest, and the extra rejection from the ToF allows the proton tagger to operate at the high luminosity required for measurement of the processes. The prototype detector uses fused silica bars emitting Cherenkov radiation as a relativistic particle passes through it. The emitted Cherenkov photons are detected by a micro-channel plate multi-anode Photomultiplier Tube (MCP-PMT) and processed by fast electronics.

  20. MCP PMT with high time response and linear output current for neutron time-of-flight detectors

    NASA Astrophysics Data System (ADS)

    Dolotov, A. S.; Konovalov, P. I.; Nurtdinov, R. I.

    2016-09-01

    A microchannel plate (MCP) photomultiplier tube (PMT) with a subnanosecond time response and a high linear output current has been developed. PMT is designed for detection of weak pulses of radiation in UV-, visible and nearer-IR ranges and can be used in neutron time-of-flight (nTOF) detectors in experiments on laser compression of thermonuclear fuel. The results of measurements of MCP PMT main parameters are presented: photocathode spectral sensitivity, gain, maximum linear output current, and time response.

  1. Characterization of neutron scatter for the 25-m neutron time of flight detector at the Z Accelerator

    NASA Astrophysics Data System (ADS)

    Norris, Edward; Hahn, Kelly; Chandler, Gordon; Ruiz, Carlos; Styron, Jedediah; Cooper, Gary; Jones, Brent; Torres, Jose; Spencer, Decker; Nelson, Alan

    2016-10-01

    We are investigating neutron scattering effects using Monte Carlo simulations for neutron time of flight (NTOF) detectors fielded at the Z Accelerator at Sandia National Laboratories. For the radial NTOF detector at 25 m, a large scatter distribution is observed during and after primary DD neutron signals produced during inertial-confinement fusion experiments which obfuscates inference of quantities such as ion temperature, yield, and liner areal density. We present comparisons of measurements with simulation results. We also propose improvements to this line-of-sight. Sandia is sponsored by the U.S. DOE's NNSA under contract DE-AC04-94AL85000.

  2. Investigating ion-surface collisions with a niobium superconducting tunnel junction detector in a time-of-flight mass spectrometer

    SciTech Connect

    Westmacott, G.; Zhong, F.; Frank, M.; Friedrich, S.; Labov, S.; Benner, W.H.

    1999-12-01

    The performance of an energy sensitive, niobium superconducting tunnel junction detector is investigated by measuring the pulse height produced by impacting molecular and atomic ions at different kinetic energies. Ions are produced by laser resorption and matrix-assisted laser desorption in a time-of-flight mass spectrometer. Results show that the STJ detector pulse height decreases for increasing molecular ion mass, passes through a minimum at around 2000 Da, and the increases with increasing mass of molecular ions above 2000Da. The detector does not show a decline in sensitivity for high mass ions as is observed with microchannel plate ion detectors. These detector plus height measurements are discussed in terms of several physical mechanisms involved in an ion-surface collision.

  3. Use of a large time-compensated scintillation detector in neutron time-of-flight measurements

    DOEpatents

    Goodman, Charles D.

    1979-01-01

    A scintillator for neutron time-of-flight measurements is positioned at a desired angle with respect to the neutron beam, and as a function of the energy thereof, such that the sum of the transit times of the neutrons and photons in the scintillator are substantially independent of the points of scintillations within the scintillator. Extrapolated zero timing is employed rather than the usual constant fraction timing. As a result, a substantially larger scintillator can be employed that substantially increases the data rate and shortens the experiment time.

  4. Design of Cherenkov bars for the optical part of the time-of-flight detector in Geant4.

    PubMed

    Nozka, L; Brandt, A; Rijssenbeek, M; Sykora, T; Hoffman, T; Griffiths, J; Steffens, J; Hamal, P; Chytka, L; Hrabovsky, M

    2014-11-17

    We present the results of studies devoted to the development and optimization of the optical part of a high precision time-of-flight (TOF) detector for the Large Hadron Collider (LHC). This work was motivated by a proposal to use such a detector in conjunction with a silicon detector to tag and measure protons from interactions of the type p + p → p + X + p, where the two outgoing protons are scattered in the very forward directions. The fast timing detector uses fused silica (quartz) bars that emit Cherenkov radiation as a relativistic particle passes through and the emitted Cherenkov photons are detected by, for instance, a micro-channel plate multi-anode Photomultiplier Tube (MCP-PMT). Several possible designs are implemented in Geant4 and studied for timing optimization as a function of the arrival time, and the number of Cherenkov photons reaching the photo-sensor.

  5. Fusion neutron detector for time-of-flight measurements in z-pinch and plasma focus experiments

    SciTech Connect

    Klir, D.; Kravarik, J.; Kubes, P.; Rezac, K.; Litseva, E.; Tomaszewski, K.; Karpinski, L.; Paduch, M.; Scholz, M.

    2011-03-15

    We have developed and tested sensitive neutron detectors for neutron time-of-flight measurements in z-pinch and plasma focus experiments with neutron emission times in tens of nanoseconds and with neutron yields between 10{sup 6} and 10{sup 12} per one shot. The neutron detectors are composed of a BC-408 fast plastic scintillator and Hamamatsu H1949-51 photomultiplier tube (PMT). During the calibration procedure, a PMT delay was determined for various operating voltages. The temporal resolution of the neutron detector was measured for the most commonly used PMT voltage of 1.4 kV. At the PF-1000 plasma focus, a novel method of the acquisition of a pulse height distribution has been used. This pulse height analysis enabled to determine the single neutron sensitivity for various neutron energies and to calibrate the neutron detector for absolute neutron yields at about 2.45 MeV.

  6. Deuterium-tritium neutron yield measurements with the 4.5 m neutron-time-of-flight detectors at NIF.

    PubMed

    Moran, M J; Bond, E J; Clancy, T J; Eckart, M J; Khater, H Y; Glebov, V Yu

    2012-10-01

    The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator∕photodetector neutron-time-of-flight (nTOF) detectors for measuring deuterium-deuterium (DD) and DT neutron yields. The detectors provided consistent neutron yield (Y(n)) measurements from below 10(9) (DD) to nearly 10(15) (DT). The detectors initially demonstrated detector-to-detector Y(n) precisions better than 5%, but lacked in situ absolute calibrations. Recent experiments at NIF now have provided in situ DT yield calibration data that establish the absolute sensitivity of the 4.5 m differential tissue harmonic imaging (DTHI) detector with an accuracy of ± 10% and precision of ± 1%. The 4.5 m nTOF calibration measurements also have helped to establish improved detector impulse response functions and data analysis methods, which have contributed to improving the accuracy of the Y(n) measurements. These advances have also helped to extend the usefulness of nTOF measurements of ion temperature and downscattered neutron ratio (neutron yield 10-12 MeV divided by yield 13-15 MeV) with other nTOF detectors.

  7. Time-of-Flight Detector System with Low Background Performance for the IBEX-lo Sensor

    NASA Astrophysics Data System (ADS)

    Moebius, E.; Kucharek, H.; Granoff, M.; King, B.; Longworth, S.; Saul, L.; Fuselier, S.; Hertzberg, E.; Livi, S.; Paschalidis, N.; Schlemm, C.; Scheer, J.; Wurz, P.; Wieser, M.

    2006-12-01

    Over the course of the IBEX Mission the IBEX-lo sensor will provide images of energetic neutral H atoms (ENA) from the termination shock in the energy range 10 2000 eV as well as the directional flow distribution of interstellar neutral O in spring and fall. The sensor combines a mechanical collimator to restrict the detectable arrival directions, an atom to negative ion conversion surface, an electrostatic analyzer, post-acceleration of up to 20 keV, and time-of-flight (TOF) mass analysis. In this combination the TOF system provides the necessary mass separation to distinguish different species and effective background suppression through coincidence detection techniques. Because the flux of the heliospheric ENAs is very low and generates rather low count rates a triple coincidence system is used with secondary electrons produced in two consecutive carbon foils, followed by the final detection of the ions in a micro-channelplate. These three signals are combined into three independent TOF measurements. A flight-like engineering test unit of the IBEX-lo TOF subsystem has been built and tested. Meanwhile the flight model of the sensor is in fabrication. It will be shown that the combination of several TOF measurements provides very effective means to suppress background and to identify minor species, whose fluxes are several orders of magnitude below the main species. Results from the testing of the engineering unit will be discussed in the light of the IBEX science objectives.

  8. First characterization of a digital SiPM based time-of-flight PET detector with 1 mm spatial resolution.

    PubMed

    Seifert, Stefan; van der Lei, Gerben; van Dam, Herman T; Schaart, Dennis R

    2013-05-07

    Monolithic scintillator detectors can offer a combination of spatial resolution, energy resolution, timing performance, depth-of-interaction information, and detection efficiency that make this type of detector a promising candidate for application in clinical, time-of-flight (TOF) positron emission tomography (PET). In such detectors the scintillation light is distributed over a relatively large number of photosensor pixels and the light intensity per pixel can be relatively low. Therefore, monolithic scintillator detectors are expected to benefit from the low readout noise offered by a novel photosensor called the digital silicon photomultiplier (dSiPM). Here, we present a first experimental characterization of a TOF PET detector comprising a 24 × 24 × 10 mm(3) LSO:Ce,0.2%Ca scintillator read out by a dSiPM array (DPC-6400-44-22) developed by Philips Digital Photon Counting. A spatial resolution of ~1 mm full-width-at-half-maximum (FWHM) averaged over the entire crystal was obtained (varying from just below 1 mm FWHM in the detector center to ~1.2 mm FWHM close to the edges). Furthermore, the bias in the position estimation at the crystal edges that is typically found in monolithic scintillators is well below 1 mm even in the corners of the crystal.

  9. Experience using an automated fault location system with a time-of-flight wall detector array

    NASA Astrophysics Data System (ADS)

    Olson, D.; Greiman, W.; Hall, D.; Balaban, D.; Day, C.

    1990-08-01

    We describe the architecture of a general purpose monitoring system and give examples of its use with a 300 element detector array in a relativistic heavy ion experiment. The system has a simple and well defined interface between the detector specific parts of the system and those which are independent of any detector specific features. Tracking simple statistics on the fundamental data items (ADC and TDC values) are sufficient to diagnose the higher level components in the system. The monitoring of on-line beam data provides a sensitive monitor of global parameters of the experiment.

  10. Antipodal neutron time of flight (nToF) detectors more than double their diagnostic value

    NASA Astrophysics Data System (ADS)

    Kilkenny, Joseph; Knauer, James; Caggiano, Joseph; Eckart, Mark; Hatarik, Robert; Munro, David; Sayre, Daniel; Spears, Brian

    2014-10-01

    Moments of the neutron-velocity distribution give unique insights to the quality of an inertial confinement fusion (ICF) implosion. The three, 20 m distance nToF detectors on the NIF are being augmented by adding an antipodal detector to each of them. Antipodal pairs of detectors increase the sampling of imploded DT ice but also allow an accurate measurement of the areal density of the odd modes of the compressed ice from the un-scattered yield ratio, and with the two measurements distinguishing center of mass drift velocity from the thermodynamic ion temperature. NNSA Contract Number DE-AC52-07NA27344.

  11. A technique for verifying the input response function of neutron time-of-flight scintillation detectors using cosmic rays

    SciTech Connect

    Bonura, M. A.; Cooper, G. W.; Nelson, A. J.; Styron, J. D.; Ruiz, C. L. Fehl, D. L.; Chandler, G.; Hahn, K. D.; Torres, J. A.

    2014-11-15

    An accurate interpretation of DD or DT fusion neutron time-of-flight (nTOF) signals from current mode detectors employed at the Z-facility at Sandia National Laboratories requires that the instrument response functions (IRF’s) be deconvolved from the measured nTOF signals. A calibration facility that produces detectable sub-ns radiation pulses is typically used to measure the IRF of such detectors. This work, however, reports on a simple method that utilizes cosmic radiation to measure the IRF of nTOF detectors, operated in pulse-counting mode. The characterizing metrics reported here are the throughput delay and full-width-at-half-maximum. This simple approach yields consistent IRF results with the same detectors calibrated in 2007 at a LINAC bremsstrahlung accelerator (Idaho State University). In particular, the IRF metrics from these two approaches and their dependence on the photomultipliers bias agree to within a few per cent. This information may thus be used to verify if the IRF for a given nTOF detector employed at Z has changed since its original current-mode calibration and warrants re-measurement.

  12. A New Neutron Time-of-Flight Detector for DT Yield and Ion-Temperature Measurements on OMEGA

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Forrest, C. J.; Knauer, J. P.; Regan, S. P.; Sangster, T. C.; Stoeckl, C.

    2015-11-01

    A new neutron time-of-flight (nTOF) detector for DT yield and ion-temperature measurements in DT implosions on the OMEGA Laser System was designed, fabricated, tested, and calibrated. The goal of this detector is to provide a second line of sight for DT yield and ion-temperature measurements in the 1 ×1012 to 1014 yield range. The nTOF detector consists of a 40-mm-diam, 20-mm-thick BC-422Q(1%) scintillator coupled with a one-stage Photek PMT-140 photomultiplier tube. To avoid PMT saturation at high yields a neutral density filter ND1 is inserted between the scintillator and PMT. Both the scintillator and PMT are shielded from hard x rays by 5 mm of lead on all sides and 10 mm in the direction of the target. The nTOF detector is located at 15.8 m from target chamber center in the OMEGA Target Bay. The design details and calibration results of this nTOF detector in DT implosions on OMEGA will be presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  13. A technique for verifying the input response function of neutron time-of-flight scintillation detectors using cosmic rays.

    PubMed

    Bonura, M A; Ruiz, C L; Fehl, D L; Cooper, G W; Chandler, G; Hahn, K D; Nelson, A J; Styron, J D; Torres, J A

    2014-11-01

    An accurate interpretation of DD or DT fusion neutron time-of-flight (nTOF) signals from current mode detectors employed at the Z-facility at Sandia National Laboratories requires that the instrument response functions (IRF's) be deconvolved from the measured nTOF signals. A calibration facility that produces detectable sub-ns radiation pulses is typically used to measure the IRF of such detectors. This work, however, reports on a simple method that utilizes cosmic radiation to measure the IRF of nTOF detectors, operated in pulse-counting mode. The characterizing metrics reported here are the throughput delay and full-width-at-half-maximum. This simple approach yields consistent IRF results with the same detectors calibrated in 2007 at a LINAC bremsstrahlung accelerator (Idaho State University). In particular, the IRF metrics from these two approaches and their dependence on the photomultipliers bias agree to within a few per cent. This information may thus be used to verify if the IRF for a given nTOF detector employed at Z has changed since its original current-mode calibration and warrants re-measurement.

  14. A technique for verifying the input response function of neutron time-of-flight scintillation detectors using cosmic raysa)

    NASA Astrophysics Data System (ADS)

    Bonura, M. A.; Ruiz, C. L.; Fehl, D. L.; Cooper, G. W.; Chandler, G.; Hahn, K. D.; Nelson, A. J.; Styron, J. D.; Torres, J. A.

    2014-11-01

    An accurate interpretation of DD or DT fusion neutron time-of-flight (nTOF) signals from current mode detectors employed at the Z-facility at Sandia National Laboratories requires that the instrument response functions (IRF's) be deconvolved from the measured nTOF signals. A calibration facility that produces detectable sub-ns radiation pulses is typically used to measure the IRF of such detectors. This work, however, reports on a simple method that utilizes cosmic radiation to measure the IRF of nTOF detectors, operated in pulse-counting mode. The characterizing metrics reported here are the throughput delay and full-width-at-half-maximum. This simple approach yields consistent IRF results with the same detectors calibrated in 2007 at a LINAC bremsstrahlung accelerator (Idaho State University). In particular, the IRF metrics from these two approaches and their dependence on the photomultipliers bias agree to within a few per cent. This information may thus be used to verify if the IRF for a given nTOF detector employed at Z has changed since its original current-mode calibration and warrants re-measurement.

  15. A combined time-of-flight and depth-of-interaction detector for total-body positron emission tomography

    PubMed Central

    Berg, Eric; Roncali, Emilie; Kapusta, Maciej; Du, Junwei; Cherry, Simon R.

    2016-01-01

    Purpose: In support of a project to build a total-body PET scanner with an axial field-of-view of 2 m, the authors are developing simple, cost-effective block detectors with combined time-of-flight (TOF) and depth-of-interaction (DOI) capabilities. Methods: This work focuses on investigating the potential of phosphor-coated crystals with conventional PMT-based block detector readout to provide DOI information while preserving timing resolution. The authors explored a variety of phosphor-coating configurations with single crystals and crystal arrays. Several pulse shape discrimination techniques were investigated, including decay time, delayed charge integration (DCI), and average signal shapes. Results: Pulse shape discrimination based on DCI provided the lowest DOI positioning error: 2 mm DOI positioning error was obtained with single phosphor-coated crystals while 3–3.5 mm DOI error was measured with the block detector module. Minimal timing resolution degradation was observed with single phosphor-coated crystals compared to uncoated crystals, and a timing resolution of 442 ps was obtained with phosphor-coated crystals in the block detector compared to 404 ps without phosphor coating. Flood maps showed a slight degradation in crystal resolvability with phosphor-coated crystals; however, all crystals could be resolved. Energy resolution was degraded by 3%–7% with phosphor-coated crystals compared to uncoated crystals. Conclusions: These results demonstrate the feasibility of obtaining TOF–DOI capabilities with simple block detector readout using phosphor-coated crystals. PMID:26843254

  16. A combined time-of-flight and depth-of-interaction detector for total-body positron emission tomography

    SciTech Connect

    Berg, Eric Roncali, Emilie; Du, Junwei; Cherry, Simon R.; Kapusta, Maciej

    2016-02-15

    Purpose: In support of a project to build a total-body PET scanner with an axial field-of-view of 2 m, the authors are developing simple, cost-effective block detectors with combined time-of-flight (TOF) and depth-of-interaction (DOI) capabilities. Methods: This work focuses on investigating the potential of phosphor-coated crystals with conventional PMT-based block detector readout to provide DOI information while preserving timing resolution. The authors explored a variety of phosphor-coating configurations with single crystals and crystal arrays. Several pulse shape discrimination techniques were investigated, including decay time, delayed charge integration (DCI), and average signal shapes. Results: Pulse shape discrimination based on DCI provided the lowest DOI positioning error: 2 mm DOI positioning error was obtained with single phosphor-coated crystals while 3–3.5 mm DOI error was measured with the block detector module. Minimal timing resolution degradation was observed with single phosphor-coated crystals compared to uncoated crystals, and a timing resolution of 442 ps was obtained with phosphor-coated crystals in the block detector compared to 404 ps without phosphor coating. Flood maps showed a slight degradation in crystal resolvability with phosphor-coated crystals; however, all crystals could be resolved. Energy resolution was degraded by 3%–7% with phosphor-coated crystals compared to uncoated crystals. Conclusions: These results demonstrate the feasibility of obtaining TOF–DOI capabilities with simple block detector readout using phosphor-coated crystals.

  17. Mechanical Modulation of Phonon-Assisted Field Emission in a Silicon Nanomembrane Detector for Time-of-Flight Mass Spectrometry

    PubMed Central

    Park, Jonghoo; Blick, Robert H.

    2016-01-01

    We demonstrate mechanical modulation of phonon-assisted field emission in a free-standing silicon nanomembrane detector for time-of-flight mass spectrometry of proteins. The impacts of ion bombardment on the silicon nanomembrane have been explored in both mechanical and electrical points of view. Locally elevated lattice temperature in the silicon nanomembrane, resulting from the transduction of ion kinetic energy into thermal energy through the ion bombardment, induces not only phonon-assisted field emission but also a mechanical vibration in the silicon nanomembrane. The coupling of these mechanical and electrical phenomenon leads to mechanical modulation of phonon-assisted field emission. The thermal energy relaxation through mechanical vibration in addition to the lateral heat conduction and field emission in the silicon nanomembrane offers effective cooling of the nanomembrane, thereby allowing high resolution mass analysis. PMID:26861329

  18. Determining time resolution of microchannel plate detectors for electron time-of-flight spectrometers

    SciTech Connect

    Zhang Qi; Zhao Kun; Chang Zenghu

    2010-07-15

    The temporal resolution of a 40 mm diameter chevron microchannel plate (MCP) detector followed by a constant fraction discriminator and a time-to-digital converter was determined by using the third order harmonic of 25 fs Ti:sapphire laser pulses. The resolution was found to deteriorate from 200 to 300 ps as the total voltage applied on the two MCPs increased from 1600 to 2000 V. This was likely due to a partial saturation of the MCP and/or the constant fraction discriminator working with signals beyond its optimum range of pulse width and shape.

  19. A combined segmented anode gas ionization chamber and time-of-flight detector for heavy ion elastic recoil detection analysis

    NASA Astrophysics Data System (ADS)

    Ström, Petter; Petersson, Per; Rubel, Marek; Possnert, Göran

    2016-10-01

    A dedicated detector system for heavy ion elastic recoil detection analysis at the Tandem Laboratory of Uppsala University is presented. Benefits of combining a time-of-flight measurement with a segmented anode gas ionization chamber are demonstrated. The capability of ion species identification is improved with the present system, compared to that obtained when using a single solid state silicon detector for the full ion energy signal. The system enables separation of light elements, up to Neon, based on atomic number while signals from heavy elements such as molybdenum and tungsten are separated based on mass, to a sample depth on the order of 1 μm. The performance of the system is discussed and a selection of material analysis applications is given. Plasma-facing materials from fusion experiments, in particular metal mirrors, are used as a main example for the discussion. Marker experiments using nitrogen-15 or oxygen-18 are specific cases for which the described improved species separation and sensitivity are required. Resilience to radiation damage and significantly improved energy resolution for heavy elements at low energies are additional benefits of the gas ionization chamber over a solid state detector based system.

  20. Time-over-threshold for pulse shape discrimination in a time-of-flight phoswich PET detector.

    PubMed

    Chang, Chen-Ming; Cates, Joshua W; Levin, Craig S

    2017-01-07

    It is well known that a PET detector capable of measuring both photon time-of-flight (TOF) and depth-of-interaction (DOI) improves the image quality and accuracy. Phoswich designs have been realized in PET detectors to measure DOI for more than a decade. However, PET detectors based on phoswich designs put great demand on the readout circuits, which have to differentiate the pulse shape produced by different crystal layers. A simple pulse shape discrimination approach is required to realize the phoswich designs in a clinical PET scanner, which consists of thousands of scintillation crystal elements. In this work, we studied time-over-threshold (ToT) as a pulse shape parameter for DOI. The energy, timing and DOI performance were evaluated for a phoswich detector design comprising [Formula: see text] mm LYSO:Ce crystal optically coupled to [Formula: see text] mm calcium co-doped LSO:Ce,Ca(0.4%) crystal read out by a silicon photomultiplier (SiPM). A DOI accuracy of 97.2% has been achieved for photopeak events using the proposed time-over-threshold (ToT) processing. The energy resolution without correction for SiPM non-linearity was [Formula: see text]% and [Formula: see text]% FWHM at 511 keV for LYSO and LSO crystal layers, respectively. The coincidence time resolution for photopeak events ranges from 164.6 ps to 183.1 ps FWHM, depending on the layer combinations. The coincidence time resolution for inter-crystal scatter events ranges from 214.6 ps to 418.3 ps FWHM, depending on the energy windows applied. These results show great promises of using ToT for pulse shape discrimination in a TOF phoswich detector since a ToT measurement can be easily implemented in readout electronics.

  1. New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector

    NASA Astrophysics Data System (ADS)

    Linnarsson, M. K.; Hallén, A.; Åström, J.; Primetzhofer, D.; Legendre, S.; Possnert, G.

    2012-09-01

    A new beam line for medium energy ion mass scattering (MEIS) has been designed and set up at the Ångström laboratory, Uppsala University, Sweden. This MEIS system is based on a time-of-flight (ToF) concept and the electronics for beam chopping relies on a 4 MHz function generator. Repetition rates can be varied between 1 MHz and 63 kHz and pulse widths below 1 ns are typically obtained by including beam bunching. A 6-axis goniometer is used at the target station. Scattering angle and energy of backscattered ions are extracted from a time-resolved and position-sensitive detector. Examples of the performance are given for three kinds of probing ions, 1H+, 4He+, and 11B+. Depth resolution is in the nanometer range and 1 and 2 nm thick Pt layers can easily be resolved. Mass resolution between nearby isotopes can be obtained as illustrated by Ga isotopes in GaAs. Taking advantage of the large size detector, a direct imaging (blocking pattern) of crystal channels are shown for hexagonal, 4H-SiC. The ToF-MEIS system described in this paper is intended for use in semiconductor and thin film areas. For example, depth profiling in the sub nanometer range for device development of contacts and dielectric interfaces. In addition to applied projects, fundamental studies of stopping cross sections in this medium energy range will also be conducted.

  2. Time-over-threshold for pulse shape discrimination in a time-of-flight phoswich PET detector

    NASA Astrophysics Data System (ADS)

    Chang, Chen-Ming; Cates, Joshua W.; Levin, Craig S.

    2017-01-01

    It is well known that a PET detector capable of measuring both photon time-of-flight (TOF) and depth-of-interaction (DOI) improves the image quality and accuracy. Phoswich designs have been realized in PET detectors to measure DOI for more than a decade. However, PET detectors based on phoswich designs put great demand on the readout circuits, which have to differentiate the pulse shape produced by different crystal layers. A simple pulse shape discrimination approach is required to realize the phoswich designs in a clinical PET scanner, which consists of thousands of scintillation crystal elements. In this work, we studied time-over-threshold (ToT) as a pulse shape parameter for DOI. The energy, timing and DOI performance were evaluated for a phoswich detector design comprising 3~\\text{mm}× 3~\\text{mm}× 10 mm LYSO:Ce crystal optically coupled to 3~\\text{mm}× 3~\\text{mm}× 10 mm calcium co-doped LSO:Ce,Ca(0.4%) crystal read out by a silicon photomultiplier (SiPM). A DOI accuracy of 97.2% has been achieved for photopeak events using the proposed time-over-threshold (ToT) processing. The energy resolution without correction for SiPM non-linearity was 9.7+/- 0.2 % and 11.3+/- 0.2 % FWHM at 511 keV for LYSO and LSO crystal layers, respectively. The coincidence time resolution for photopeak events ranges from 164.6 ps to 183.1 ps FWHM, depending on the layer combinations. The coincidence time resolution for inter-crystal scatter events ranges from 214.6 ps to 418.3 ps FWHM, depending on the energy windows applied. These results show great promises of using ToT for pulse shape discrimination in a TOF phoswich detector since a ToT measurement can be easily implemented in readout electronics.

  3. Electronic Microchannel Plate Particle Detector Design for a CubeSat Time-of-Flight Reflectron Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Pyle, M. L.; Davidson, R.; Swenson, C.; Syrstad, E. A.

    2015-12-01

    Variations of gas density and composition in Earth's thermosphere and ionosphere are key indicators of interactions between different layers of Earth's atmosphere. The nature of interactions between neutral and ion species in the upper atmosphere is an active area of study in Heliophysics and there is much to learn about the dynamic relationship between the ionosphere and neutral thermosphere. Mass Spectrometers are among an array of instruments used to explore Earth's upper atmosphere and other space environments. Normally, these instruments are substantial in size and deployed on larger satellites. Data from these larger instruments generally provides information from a specific point in time at a single location. Studies of atmospheric density and composition with multiple locations for each time point could be performed by CubeSat swarms if proper instrumentation were available to fit CubeSat payload restrictions. The proposed miniaturized time-of-flight (TOF) mass spectrometer (MS) will have a mass resolution and range sufficient for measuring the composition of Earth's thermosphere and ionosphere while operating within the power and space constraints of a CubeSat. The capabilities of this instrument would potentially dramatically reduce the cost of future missions while simultaneously enhancing the science return. The design employs miniaturization of TOF-MS technology, including resolution refinement techniques used for larger instruments and standard concepts for TOF-MS components such as acceleration grids, a Bradbury-Nielsen wire gate, a gridless ion mirror, and microchannel plate detector (MCP). The quality of particle detection is known to have a significant impact on the instrument performance. A signal collector for an MCP detector is being designed to maximize the detection performance and enable the transmission of density and composition data back to Earth.

  4. ALICE Diffractive Detector Control System for RUN-II in the ALICE Experiment

    NASA Astrophysics Data System (ADS)

    Cabanillas, J. C.; Martínez, M. I.; León, I.

    2016-10-01

    The ALICE Diffractive (AD0) detector has been installed and commissioned for the second phase of operation (RUN-II). With this new detector it is possible to achieve better measurements by expanding the range of pseudo-rapidity in which the production of particles can be detected. Specifically the selection of diffractive events in the ALICE experiment which was limited by the range over which rapidity gaps occur. Any new detector should be able to take data synchronously with all other detectors and to be operated through the ALICE central systems. One of the key elements developed for the AD0 detector is the Detector Control System (DCS). The DCS is designed to operate safely and correctly this detector. Furthermore, the DCS must also provide optimum operating conditions for the acquisition and storage of physics data and ensure these are of the highest quality. The operation of AD0 implies the configuration of about 200 parameters, as electronics settings and power supply levels and the generation of safety alerts. It also includes the automation of procedures to get the AD0 detector ready for taking data in the appropriate conditions for the different run types in ALICE. The performance of AD0 detector depends on a certain number of parameters such as the nominal voltages for each photomultiplier tube (PMT), the threshold levels to accept or reject the incoming pulses, the definition of triggers, etc. All these parameters affect the efficiency of AD0 and they have to be monitored and controlled by the AD0 DCS.

  5. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    DOE PAGES

    Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; ...

    2015-05-27

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition,more » comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.« less

  6. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    SciTech Connect

    Waugh, C. J.; Rosenberg, M. J.; Zylstra, A. B.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-27

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

  7. A method for in situ absolute DD yield calibration of neutron time-of-flight detectors on OMEGA using CR-39-based proton detectors

    SciTech Connect

    Waugh, C. J. Zylstra, A. B.; Frenje, J. A.; Séguin, F. H.; Petrasso, R. D.; Rosenberg, M. J.; Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.

    2015-05-15

    Neutron time of flight (nTOF) detectors are used routinely to measure the absolute DD neutron yield at OMEGA. To check the DD yield calibration of these detectors, originally calibrated using indium activation systems, which in turn were cross-calibrated to NOVA nTOF detectors in the early 1990s, a direct in situ calibration method using CR-39 range filter proton detectors has been successfully developed. By measuring DD neutron and proton yields from a series of exploding pusher implosions at OMEGA, a yield calibration coefficient of 1.09 ± 0.02 (relative to the previous coefficient) was determined for the 3m nTOF detector. In addition, comparison of these and other shots indicates that significant reduction in charged particle flux anisotropies is achieved when bang time occurs significantly (on the order of 500 ps) after the trailing edge of the laser pulse. This is an important observation as the main source of the yield calibration error is due to particle anisotropies caused by field effects. The results indicate that the CR-39-nTOF in situ calibration method can serve as a valuable technique for calibrating and reducing the uncertainty in the DD absolute yield calibration of nTOF detector systems on OMEGA, the National Ignition Facility, and laser megajoule.

  8. Development of capacitive multiplexing circuit for SiPM-based time-of-flight (TOF) PET detector

    NASA Astrophysics Data System (ADS)

    Choe, Hyeok-Jun; Choi, Yong; Hu, Wei; Yan, Jianhua; Jung, Jin Ho

    2017-04-01

    There has been great interest in developing a time-of-flight (TOF) PET to improve the signal-to-noise ratio of PET image relative to that of non-TOF PET. Silicon photomultiplier (SiPM) arrays have attracted attention for use as a fast TOF PET photosensor. Since numerous SiPM arrays are needed to construct a modern human PET, a multiplexing method providing both good timing performance and high channel reduction capability is required to develop a SiPM-based TOF PET. The purpose of this study was to develop a capacitive multiplexing circuit for the SiPM-based TOF PET. The proposed multiplexing circuit was evaluated by measuring the coincidence resolving time (CRT) and the energy resolution as a function of the overvoltage using three different capacitor values of 15, 30, and 51 pF. A flood histogram was also obtained and quantitatively assessed. Experiments were performed using a 4× 4 array of 3× 3 mm2 SiPMs. Regarding the capacitor values, the multiplexing circuit using a smaller capacitor value showed the best timing performance. On the other hand, the energy resolution and flood histogram quality of the multiplexing circuit deteriorated as the capacitor value became smaller. The proposed circuit was able to achieve a CRT of 260+/- 4 ps FWHM and an energy resolution of 17.1 % with a pair of 2× 2× 20 mm3 LYSO crystals using a capacitor value of 30 pF at an overvoltage of 3.0 V. It was also possible to clearly resolve a 6× 6 array of LYSO crystals in the flood histogram using the multiplexing circuit. The experiment results indicate that the proposed capacitive multiplexing circuit is useful to obtain an excellent timing performance and a crystal-resolving capability in the flood histogram with a minimal degradation of the energy resolution, as well as to reduce the number of the readout channels of the SiPM-based TOF PET detector.

  9. Development of capacitive multiplexing circuit for SiPM-based time-of-flight (TOF) PET detector.

    PubMed

    Choe, Hyeok-Jun; Choi, Yong; Hu, Wei; Yan, Jianhua; Ho Jung, Jin

    2017-04-07

    There has been great interest in developing a time-of-flight (TOF) PET to improve the signal-to-noise ratio of PET image relative to that of non-TOF PET. Silicon photomultiplier (SiPM) arrays have attracted attention for use as a fast TOF PET photosensor. Since numerous SiPM arrays are needed to construct a modern human PET, a multiplexing method providing both good timing performance and high channel reduction capability is required to develop a SiPM-based TOF PET. The purpose of this study was to develop a capacitive multiplexing circuit for the SiPM-based TOF PET. The proposed multiplexing circuit was evaluated by measuring the coincidence resolving time (CRT) and the energy resolution as a function of the overvoltage using three different capacitor values of 15, 30, and 51 pF. A flood histogram was also obtained and quantitatively assessed. Experiments were performed using a [Formula: see text] array of [Formula: see text] mm(2) SiPMs. Regarding the capacitor values, the multiplexing circuit using a smaller capacitor value showed the best timing performance. On the other hand, the energy resolution and flood histogram quality of the multiplexing circuit deteriorated as the capacitor value became smaller. The proposed circuit was able to achieve a CRT of [Formula: see text] ps FWHM and an energy resolution of 17.1[Formula: see text] with a pair of [Formula: see text] mm(3) LYSO crystals using a capacitor value of 30 pF at an overvoltage of 3.0 V. It was also possible to clearly resolve a [Formula: see text] array of LYSO crystals in the flood histogram using the multiplexing circuit. The experiment results indicate that the proposed capacitive multiplexing circuit is useful to obtain an excellent timing performance and a crystal-resolving capability in the flood histogram with a minimal degradation of the energy resolution, as well as to reduce the number of the readout channels of the SiPM-based TOF PET detector.

  10. The Fast Interaction Trigger detector for the ALICE Upgrade

    NASA Astrophysics Data System (ADS)

    Karavicheva, T. L.; ALICE Collaboration

    2017-01-01

    As a result of the LHC injectors upgrade after the Long Shutdown (2019-2020), the expected Pb-Pb luminosity and collision rate during the so called Runs 3 and 4 will considerably exceed the design parameters for several of the key ALICE detectors systems including the forward trigger detectors. Fast Interaction Trigger (FIT) will be the primary forward trigger, luminosity, and collision time measurement detector. It will also determine multiplicity, centrality, and reaction plane of heavy ion collisions. FIT is expected to match and even exceed the functionality and performance currently secured by three ALICE sub-detectors: the time zero detector (T0), the VZERO system (V0), and the Forward Multiplicity Detector (FMD). FIT will consist of two arrays of Cherenkov radiators with MCP-PMT sensors and of a single, large-size scintillator ring. Because of the presence of the muon spectrometer, the placement of the FIT arrays will be asymmetric: ∼800 mm from the interaction point (IP) on the absorber side and ∼3200 mm from IP on the opposite side. The ongoing beam tests and Monte Carlo studies verify the physics performance and refine the geometry of the FIT arrays. The presentation gives a short description of FIT, triggers and readout requirement for the ALICE Upgrade, a summary of the performance, and the outcome of the simulations and beam tests.

  11. Online processing in the ALICE DAQ The detector algorithms

    NASA Astrophysics Data System (ADS)

    Chapeland, S.; Altini, V.; Carena, F.; Carena, W.; Chibante Barroso, V.; Costa, F.; Divià, R.; Fuchs, U.; Makhlyueva, I.; Roukoutakis, F.; Schossmaier, K.; Soós, C.; Vande Vyvre, P.; von Haller, B.; ALICE Collaboration

    2010-04-01

    ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Some specific calibration tasks are performed regularly for each of the 18 ALICE sub-detectors in order to achieve most accurate physics measurements. These procedures involve events analysis in a wide range of experimental conditions, implicating various trigger types, data throughputs, electronics settings, and algorithms, both during short sub-detector standalone runs and long global physics runs. A framework was designed to collect statistics and compute some of the calibration parameters directly online, using resources of the Data Acquisition System (DAQ), and benefiting from its inherent parallel architecture to process events. This system has been used at the experimental area for one year, and includes more than 30 calibration routines in production. This paper describes the framework architecture and the synchronization mechanisms involved at the level of the Experiment Control System (ECS) of ALICE. The software libraries interfacing detector algorithms (DA) to the online data flow, configuration database, experiment logbook, and offline system are reviewed. The test protocols followed to integrate and validate each sub-detector component are also discussed, including the automatic build system and validation procedures used to ensure a smooth deployment. The offline post-processing and archiving of the DA results is covered in a separate paper.

  12. A novel method for modeling the neutron time of flight detector response in current mode to inertial confinement fusion experiments (invited)

    SciTech Connect

    Nelson, A. J.; Cooper, G. W.; Ruiz, C. L.; Chandler, G. A.; Fehl, D. L.; Hahn, K. D.; Leeper, R. J.; Smelser, R.; Torres, J. A.

    2012-10-15

    A novel method for modeling the neutron time of flight (nTOF) detector response in current mode for inertial confinement fusion experiments has been applied to the on-axis nTOF detectors located in the basement of the Z-Facility. It will be shown that this method can identify sources of neutron scattering, and is useful for predicting detector responses in future experimental configurations, and for identifying potential sources of neutron scattering when experimental set-ups change. This method can also provide insight on how much broadening neutron scattering contributes to the primary signals, which is then subtracted from them. Detector time responses are deconvolved from the signals, allowing a transformation from dN/dt to dN/dE, extracting neutron spectra at each detector location; these spectra are proportional to the absolute yield.

  13. Large aperture at low cost three-dimensional time-of-flight range sensor using scanning micromirrors and synchronous detector switching.

    PubMed

    Bogatscher, Siegwart; Streck, Andreas; Fox, Maik; Meinzer, Sebastian; Heussner, Nico; Stork, Wilhelm

    2014-03-10

    In this article the problem of achieving fast scanning of a time-of-flight range sensor with a large optical receiver aperture at low system cost is targeted. The presented approach to solve this problem consists of a micromirror-based transmitter unit and a receiver unit consisting of a large aperture lens system with a small field of view and a detector array. A concept, which is called synchronous detector switching, is applied to the detector array. Thereby electronic steering of the small receiver field of view is possible. The overall approach is compared to alternative approaches, and the underlying concept of synchronous detector switching is demonstrated experimentally in an implementation of a three-dimensional time-of-flight range sensor. It is theoretically shown that the presented concept is potentially cheaper than the alternative approaches for applications with a field of view of less than 60×60°. After a discussion of the strengths and limitations of the approach, its effect on broader scientific issues is outlined.

  14. The Fast Interaction Trigger Detector of ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Lambert, Keenan; Brown, Shanice; Powell, Calvin; Harton, Austin; Garcia-Solis, Edmundo; Alice-Fit Team

    2017-01-01

    CERN (European Center for Nuclear Research) is a global laboratory that studies proton and heavy ion collisions at the Large Hadron Collider (LHC). ALICE (A Large Ion Collider Experiment) is one of four large experiments at the LHC. ALICE is dedicated to the study of the transition of matter to Quark-Gluon Plasma in heavy ion collisions. The experiment is preparing for the LHC upgrade after the second long shutdown (LS2) in 2019-20. To this end, ALICE is undertaking a major initiative to extend its physics capabilities. Among these improvements is a new Fast Interaction Trigger (FIT). The FIT will be replacing the current T0 and V0 trigger detectors. The purpose of the FIT will be to determine multiplicity, centrality, and reaction plane. The FIT will also serve as the primary forward trigger, luminosity, and collision time detector. This presentation will discuss the FIT upgrade and the results from the performance of the FIT detectors in simulations and test beams that support the current design parameters. This material is based upon work supported by the National Science Foundation under grants NSF-PHY-1407051, NSF-PHY-1305280, NSF-PHY-1613118, and NSF-PHY-1625081.

  15. High performance diagnostics for Time-Of-Flight and X ray measurements in laser produced plasmas, based on fast diamond detectors

    NASA Astrophysics Data System (ADS)

    De Angelis, R.; Consoli, F.; Verona, C.; Di Giorgio, G.; Andreoli, P.; Cristofari, G.; Cipriani, M.; Ingenito, F.; Marinelli, M.; Verona-Rinati, G.

    2016-12-01

    The paper reports about the use of single-crystal Chemical Vapour Deposited (CVD) diamonds as radiation detectors in laser-matter interaction experiments on the ABC laser in ENEA - Frascati. The detectors have been designed and realized by University of Tor Vergata - Rome. The interdigital configuration and the new design of the bias-tee voltage supply units guarantee a fast time response. The detectors are sensitive to soft-X photons and to particles. A remarkable immunity to electromagnetic noise, associated with the laser-target interaction, makes them especially useful for the measurements of the time of flight of fast particles. A novel diamond assembly has been tested in plasmas generated by the ABC laser in the nanosecond regime at intensities I=1013÷ 14 W/cm2, where contributions from X rays, fast electrons and ions could be observed.

  16. Readout strategy of an electro-optical coupled PET detector for time-of-flight PET/MRI.

    PubMed

    Bieniosek, M F; Olcott, P D; Levin, C S

    2013-10-21

    Combining PET with MRI in a single system provides clinicians with complementary molecular and anatomical information. However, existing integrated PET/MRI systems do not have time-of-flight (ToF) PET capabilities. This work describes an MRI-compatible front-end electronic system with ToF capabilities. The approach employs a fast arrival-time pickoff comparator to digitize the timing information, and a laser diode to drive a 10 m fiber-optic cable to optically transmit asynchronous timing information to a photodiode receiver readout system. The FWHM jitter of the comparator and this electo-optical link is 11.5 ps in response to a fast digital pulse. When configured with LYSO scintillation crystals and Hamamatsu MPPC silicon photo-multipliers the comparator and electro-optical link achieved a 511 keV coincidence time resolution of 254.7 ps +/- 8.0 ps FWHM with 3 × 3 × 20 mm(3) crystals and 166.5 +/- 2.5 ps FWHM with 3 × 3 × 5 mm(3) crystals.

  17. Readout strategy of an electro-optical coupled PET detector for time-of-flight PET/MRI

    NASA Astrophysics Data System (ADS)

    Bieniosek, M. F.; Olcott, P. D.; Levin, C. S.

    2013-10-01

    Combining PET with MRI in a single system provides clinicians with complementary molecular and anatomical information. However, existing integrated PET/MRI systems do not have time-of-flight (ToF) PET capabilities. This work describes an MRI-compatible front-end electronic system with ToF capabilities. The approach employs a fast arrival-time pickoff comparator to digitize the timing information, and a laser diode to drive a 10 m fiber-optic cable to optically transmit asynchronous timing information to a photodiode receiver readout system. The FWHM jitter of the comparator and this electo-optical link is 11.5 ps in response to a fast digital pulse. When configured with LYSO scintillation crystals and Hamamatsu MPPC silicon photo-multipliers the comparator and electro-optical link achieved a 511 keV coincidence time resolution of 254.7 ps +/- 8.0 ps FWHM with 3 × 3 × 20 mm3 crystals and 166.5 +/- 2.5 ps FWHM with 3 × 3 × 5 mm3 crystals.

  18. Time-of-Flight Detector System of the IBEX-Lo Sensor with Low Background Performance for Heliospheric ENA Detection

    NASA Astrophysics Data System (ADS)

    Möbius, E.; Fuselier, S.; Granoff, M.; Hertzberg, E.; King, B.; Kucharek, H.; Livi, S.; Longworth, S.; Paschalidis, N.; Saul, L.; Scheer, J.; Schlemm, C.; Wieser, M.; Wurz, P.

    IBEX-lo on the Interstellar Boundary Explorer (IBEX) will image energetic neutral H atoms (ENA) from the termination shock at 10 - 2000 eV and the flow distribution of interstellar O in spring and fall. The sensor combines a mechanical collimator to restrict the detectable arrival directions, an atom to negative ion conversion surface, an electrostatic analyzer, post-acceleration up to 20 keV, and time-of-flight (TOF) analysis, providing species separation and effective background suppression. Because the flux of the heliospheric ENAs is very low a triple coincidence system is used with secondary electrons produced at two consecutive carbon foils, followed by detection of the ions in a micro-channelplate. These signals are combined into three independent TOF measurements. Meanwhile the flight model of the TOF subsystem has been fabricated, tested and calibrated. It will be shown how the combination of several TOF measurements is very effective to suppress background to unprecedented levels and to identify minor species, whose fluxes are several orders of magnitude below the main species. Results from the testing of both the engineering and the flight unit will be discussed in the light of the IBEX science objectives to study the termination shock and the heliosheath.

  19. Absolute x-ray and neutron calibration of CVD-diamond-based time-of-flight detectors for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Rosenthal, A.; Kabadi, N. V.; Sio, H.; Rinderknecht, H.; Gatu Johnson, M.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.; Glebov, V.; Forrest, C.; Knauer, J.

    2016-10-01

    The particle-time-of-flight (pTOF) detector at the National Ignition Facility routinely measures proton and neutron nuclear bang-times in inertial confinement fusion (ICF) implosions. The active detector medium in pTOF is a chemical vapor deposition (CVD) diamond biased to 250 - 1500 V. This work discusses an absolute measurement of CVD diamond sensitivity to continuous neutrons and x-rays. Although the impulse response of the detector is regularly measured on a diagnostic timing shot, absolute sensitivity of the detector's response to neutrons and x-rays has not been fully established. X-ray, DD-n, and DT-n sources at the MIT HEDP Accelerator Facility provide continuous sources for testing. CVD diamond detectors are also fielded on OMEGA experiments to measure sensitivity to impulse DT-n. Implications for absolute neutron yield measurements at the NIF using pTOF detectors will be discussed. This work was supported in part by the U.S. DoE and LLNL.

  20. Production and assembly of the ALICE silicon drift detectors

    NASA Astrophysics Data System (ADS)

    Beolè, S.; Antinori, S.; Coli, S.; Crescio, E.; Falchieri, D.; Arteche Diaz, R.; Di Liberto, S.; Gabrielli, A.; Giraudo, G.; Giubellino, P.; Martoiu, S.; Masetti, G.; Mazza, G.; Mazzoni, M. A.; Meddi, F.; Rashevsky, A.; Riccati, L.; Rivetti, A.; Simonetti, L.; Toscano, L.; Tosello, F.; Urciuoli, G. M.; Vacchi, A.; Wheadon, R.

    2007-01-01

    The ALICE experiment at the LHC will study collisions of heavy-ions at a centre-of-mass energy ˜5.5 TeV per nucleon. The main aim of the experiment is to study in detail the behaviour of nuclear matter at high densities and temperatures, in view of probing deconfinement and chiral symmetry restoration. Silicon Drift Detectors (SDDs) have been selected to equip the two intermediate layers of the ALICE Inner Tracking System (ITS) [ALICE Collaboration, Technical Design Report, CERN/LHCC 99-12], since they couple a very good multi-track capability with dE/dx information and excellent spatial resolution as described in [E. Gatti, P. Rehak, Nucl. Instr. and Meth. A 225 (1984) 608; S. Beolé, et al., Nucl. Instr. and Meth. A 377 (1996) 393; S. Beolé, et al., Il Nuovo Cimento 109A (9) (1996)]. In this paper we describe the different components of the SDD system as well as the different procedure of the system assembly.

  1. Efficiency and rate capability studies of the time-of-flight detector for isochronous mass measurements of stored short-lived nuclei with the FRS-ESR facility

    NASA Astrophysics Data System (ADS)

    Kuzminchuk-Feuerstein, Natalia; Fabian, Benjamin; Diwisch, Marcel; Plaß, Wolfgang R.; Geissel, Hans; Ayet San Andrés, Samuel; Dickel, Timo; Knöbel, Ronja; Scheidenberger, Christoph; Sun, Baohua; Weick, Helmut

    2016-06-01

    A time-of-flight (TOF) detector is used for Isochronous Mass Spectrometry (IMS) with the projectile fragment separator FRS and the heavy-ion storage ring ESR. Exotic nuclei are spatially separated in flight with the FRS at about 70% of the speed of light and are injected into the ESR. The revolution times of the stored ions circulating in the ESR are measured with a thin transmission foil detector. When the ions penetrate the thin detector foil, secondary electrons (SEs) are emitted from the surface and provide the timing information in combination with microchannel plate (MCP) detectors. The isochronous transport of the SEs is performed by perpendicular superimposed electric and magnetic fields. The detection efficiency and the rate capability of the TOF detector have been studied in simulations and experiments. As a result the performance of the TOF detector has been improved substantially: (i) The SE collection efficiency was doubled by use of an optimized set of electric and magnetic field values; now SEs from almost the full area of the foil are transmitted to the MCP detectors. (ii) The rate capability of the TOF detector was improved by a factor of four by the use of MCPs with 5 μm pore size. (iii) With these MCPs and a carbon foil with a reduced thickness of 10 μg/cm2 the number of recorded revolutions in the ESR has been increased by nearly a factor of 10. The number of recorded revolutions determine the precision of the IMS experiments. Heavy-ion measurements were performed with neon ions at 322 MeV/u and uranium fission fragments at about 370 MeV/u. In addition, measurements with an alpha source were performed in the laboratory with a duplicate of the TOF detector.

  2. Experimental studies with two novel silicon detectors for the development of time-of-flight spectrometry of laser-accelerated proton beams

    NASA Astrophysics Data System (ADS)

    Würl, M.; Reinhardt, S.; Rosenfeld, A.; Petasecca, M.; Lerch, M.; Tran, L.; Karsch, S.; Assmann, W.; Schreiber, J.; Parodi, K.

    2017-01-01

    Laser-accelerated proton beams exhibit remarkably different beam characteristics as compared to conventionally accelerated ion beams. About 105 to 107 particles per MeV and msr are accelerated quasi-instantaneously within about 1 ps. The resulting energy spectrum typically shows an exponentially decaying distribution. Our planned approach to determine the energy spectrum of the particles generated in each pulse is to exploit the time-of-flight (TOF) difference of protons with different kinetic energies at 1 m distance from the laser-target interaction. This requires fast and sensitive detectors. We therefore tested two prototype silicon detectors, developed at the Centre for Medical Radiation Physics at the University of Wollongong with a current amplifier, regarding their suitability for TOF-spectrometry in terms of sensitivity and timing properties. For the latter, we illuminated the detectors with short laser pulses, measured the signal current and compared it to the signal of a fast photodiode. The comparison revealed that the timing properties of both prototypes are not yet sufficient for our purpose. In contrast, our results regarding the detectors’ sensitivity are promising. The lowest detectable proton flux at 10 MeV was found to be 25 protons per ns on the detector. With this sensitivity and with a smaller pixelation of the detectors, the timing properties can be improved for new prototypes, making them potential candidates for TOF-spectrometry of laser-accelerated particle beams.

  3. Monte Carlo Simulation Study on the Time Resolution of a PMT-Quadrant-Sharing LSO Detector Block for Time-of-Flight PET.

    PubMed

    Liu, Shitao; Li, Hongdi; Zhang, Yuxuan; Ramirez, Rocio A; Baghaei, Hossain; An, Shaohui; Wang, Chao; Liu, Jiguo; Wong, Wai-Hoi

    2009-01-01

    We developed a detailed Monte Carlo simulation method to study the time resolution of detectors for time-of-flight positron emission tomography (TOF PET). The process of gamma ray interaction in detectors, scintillation light emission and transport inside the detectors, the photoelectron generation and anode signal generation in the photomultiplier tube (PMT), and the electronics process of discriminator are simulated. We tested this simulation method using published experimental data, and found that it can generate reliable results. Using this method, we simulated the time resolution for a 13 × 13 detector block of 4 × 4 × 20 mm(3) lutetium orthosilicate (LSO) crystals coupled to four 2-inch PMTs using PMT-quadrant-sharing (PQS) technology. We analyzed the effects of several factors, including the number of photoelectrons, light transport, transit time spread (TTS), and the depth of interaction (DOI). The simulation results indicated that system time resolution of 360 ps should be possible with currently available fast PMTs. This simulation method can also be used to simulate the time resolution of other detector design method.

  4. A new detector array for diffractive physics in ALICE at the LHC

    SciTech Connect

    Corral, Gerardo Herrera

    2011-07-15

    We discuss some aspects of a new sub-detector for the ALICE experiment at the LHC. This detector would enhance the capabilities of ALICE to study several topics of diffractive as well as of photon induced physics. It consists of four stations of scintillator pads that would tag the diffractive gap more efficiently.

  5. Detection of Large Ions in Time-of-Flight Mass Spectrometry: Effects of Ion Mass and Acceleration Voltage on Microchannel Plate Detector Response

    NASA Astrophysics Data System (ADS)

    Liu, Ranran; Li, Qiyao; Smith, Lloyd M.

    2014-08-01

    In time-of-flight mass spectrometry (TOF-MS), ion detection is typically accomplished by the generation and amplification of secondary electrons produced by ions colliding with a microchannel plate (MCP) detector. Here, the response of an MCP detector as a function of ion mass and acceleration voltage is characterized, for singly charged peptide/protein ions ranging from 1 to 290 kDa in mass, and for acceleration voltages from 5 to 25 kV. A nondestructive inductive charge detector (ICD) employed in parallel with MCP detection provides a reliable reference signal to allow accurate calibration of the MCP response. MCP detection efficiencies were very close to unity for smaller ions at high acceleration voltages (e.g., angiotensin, 1046.5 Da, at 25 kV acceleration voltage), but decreased to ~11% for the largest ions examined (immunoglobulin G (IgG) dimer, 290 kDa) even at the highest acceleration voltage employed (25 kV). The secondary electron yield γ (average number of electrons produced per ion collision) is found to be proportional to mv3.1 (m: ion mass, v: ion velocity) over the entire mass range examined, and inversely proportional to the square root of m in TOF-MS analysis. The results indicate that although MCP detectors indeed offer superlative performance in the detection of smaller peptide/protein species, their performance does fall off substantially for larger proteins, particularly under conditions of low acceleration voltage.

  6. Detection of large ions in time-of-flight mass spectrometry: effects of ion mass and acceleration voltage on microchannel plate detector response.

    PubMed

    Liu, Ranran; Li, Qiyao; Smith, Lloyd M

    2014-08-01

    In time-of-flight mass spectrometry (TOF-MS), ion detection is typically accomplished by the generation and amplification of secondary electrons produced by ions colliding with a microchannel plate (MCP) detector. Here, the response of an MCP detector as a function of ion mass and acceleration voltage is characterized, for singly charged peptide/protein ions ranging from 1 to 290 kDa in mass, and for acceleration voltages from 5 to 25 kV. A nondestructive inductive charge detector (ICD) employed in parallel with MCP detection provides a reliable reference signal to allow accurate calibration of the MCP response. MCP detection efficiencies were very close to unity for smaller ions at high acceleration voltages (e.g., angiotensin, 1046.5 Da, at 25 kV acceleration voltage), but decreased to ~11% for the largest ions examined (immunoglobulin G (IgG) dimer, 290 kDa) even at the highest acceleration voltage employed (25 kV). The secondary electron yield γ (average number of electrons produced per ion collision) is found to be proportional to mv(3.1) (m: ion mass, v: ion velocity) over the entire mass range examined, and inversely proportional to the square root of m in TOF-MS analysis. The results indicate that although MCP detectors indeed offer superlative performance in the detection of smaller peptide/protein species, their performance does fall off substantially for larger proteins, particularly under conditions of low acceleration voltage.

  7. Managing operational documentation in the ALICE Detector Control System

    NASA Astrophysics Data System (ADS)

    Lechman, M.; Augustinus, A.; Bond, P.; Chochula, P.; Kurepin, A.; Pinazza, O.; Rosinsky, P.

    2012-12-01

    ALICE (A Large Ion Collider Experiment) is one of the big LHC (Large Hadron Collider) experiments at CERN in Geneve, Switzerland. The experiment is composed of 18 sub-detectors controlled by an integrated Detector Control System (DCS) that is implemented using the commercial SCADA package PVSSII. The DCS includes over 1200 network devices, over 1,000,000 monitored parameters and numerous custom made software components that are prepared by over 100 developers from all around the world. This complex system is controlled by a single operator via a central user interface. One of his/her main tasks is the recovery of anomalies and errors that may occur during operation. Therefore, clear, complete and easily accessible documentation is essential to guide the shifter through the expert interfaces of different subsystems. This paper describes the idea of the management of the operational documentation in ALICE using a generic repository that is built on a relational database and is integrated with the control system. The experience gained and the conclusions drawn from the project are also presented.

  8. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV.

    PubMed

    Lupone, S; Damoy, S; Husseen, A; Briand, N; Debiossac, M; Tall, S; Roncin, P

    2015-12-01

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  9. Note: A large open ratio, time, and position sensitive detector for time of flight measurements in UHV

    SciTech Connect

    Lupone, S.; Damoy, S.; Husseen, A.; Briand, N.; Debiossac, M.; Tall, S.; Roncin, P.

    2015-12-15

    We report on the construction of an UHV compatible 40 mm active diameter detector based on micro channel plates and assembled directly on the feed-throughs of a DN63CF flange. It is based on the charge division technique and uses a standard 2 inch Si wafer as a collector. The front end electronic is placed directly on the air side of the flange allowing excellent immunity to noise and a very good timing signal with reduced ringing. The important aberrations are corrected empirically providing an absolute positioning accuracy of 500 μm while a 150 μm resolution is measured in the center.

  10. Monolithic single-photon detectors and time-to-digital converters for picoseconds time-of-flight ranging

    NASA Astrophysics Data System (ADS)

    Markovic, Bojan; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2011-03-01

    We present a novel "smart-pixel" able to measure and record in-pixel the time delay (photon timing) between a START (e.g. given by laser excitation, cell stimulus, or LIDAR flash) and a STOP (e.g. arrival of the first returning photon from the fluorescence decay signal or back reflection from an object). Such smart-pixel relies of a SPAD detector and a Timeto- Digital Converter monolithically designed and manufactured in the same chip. Many pixels can be laid out in a rows by columns architecture, to give birth to expandable 2D imaging arrays for picoseconds-level single-photon timing applications. Distance measurements, by means of direct TOF detection (used in LIDAR systems) provided by each pixel, can open the way to the fabrication of single-chip 3D ranging arrays for scene reconstruction and intelligent object recognition. We report on the design and characterization of prototype circuits, fabricated in a 0.35 μm standard CMOS technology containing complete conversion channels, "smart-pixel" and ancillary electronics with 20 μm active area diameter SPAD detector and related quenching circuitry. With a 100 MHz reference clock, the TDC provides timeresolution of 10 ps, dynamic range of 160 ns and very high conversion linearity.

  11. Time and Energy Characterization of a Neutron time of Flight Detector for Re-designing Line of Sight 270 at the Z Pulsed Power Facility.

    SciTech Connect

    Styron, Jedediah D.

    2016-11-01

    This work will focus on the characterization of NTOF detectors fielded on ICF experiments conducted at the Z-experimental facility with emphasis on the MagLif and gas puff campaigns. Three experiments have been proposed. The first experiment will characterize the response of the PMT with respect to the amplitude and width of signals produced by single neutron events. A second experiment will characterize the neutron transit time through the scintillator and the third is to characterize the pulse amplitude for a very specific range of neutron induced charged particle interactions within the scintillator. These experiments will cover incident neutron energies relevant to D-D and D-T fusion reactions. These measurements will be taken as a function of detector bias to cover the entire dynamic range of the detector. Throughout the characterization process, the development of a predictive capability is desired. A new post processing code has been proposed that will calculate a neutron time-of-flight spectrum in units of MeVee. This code will couple the experimentally obtained values and the results obtained with the Monte Carlo code MCNP6. The motivation of this code is to correct for geometry issues when transferring the calibration results from a light lab setting to the Zenvironment. This capability will be used to develop a hypothetical design of LOS270 such that more favorable neutron measurements, requiring less correction, can be made in the future.

  12. Time resolution of time-of-flight detector based on multiple scintillation counters readout by SiPMs

    NASA Astrophysics Data System (ADS)

    Cattaneo, P. W.; De Gerone, M.; Gatti, F.; Nishimura, M.; Ootani, W.; Rossella, M.; Shirabe, S.; Uchiyama, Y.

    2016-08-01

    A new timing detector measuring ∼ 50 MeV / c positrons is under development for the MEG II experiment, aiming at a time resolution σt ∼ 30 ps. The resolution is expected to be achieved by measuring each positron time with multiple counters made of plastic scintillator readout by silicon photomultipliers (SiPMs). The purpose of this work is to demonstrate the time resolution for ∼ 50 MeV / c positrons using prototype counters. Counters with dimensions of 90 × 40 × 5mm3 readout by six SiPMs (three on each 40 × 5mm2 plane) were built with SiPMs from Hamamatsu Photonics and AdvanSiD and tested in a positron beam at the DAΦNE Beam Test Facility. The time resolution was found to improve nearly as the square root of the number of counter hits. A time resolution σt = 26.2 ± 1.3 ps was obtained with eight counters with Hamamatsu SiPMs. These results suggest that the design resolution is achievable in the MEG II experiment.

  13. Performance of timing RPC detectors for relativistic ions and design of a time-of-flight detector (iToF) for the R3B-FAIR experiment for fission and spallation reactions

    SciTech Connect

    Casarejos, E.; Ayyad, Y.; Benlliure, J.; Duran, I.; Paradela, C.; Lopez-Lago, M.; Segade, A.; Vilan, J. A.

    2011-07-01

    Resistive-plate-chambers (RPCs) were proposed to be used to build a time-of-flight detector for relativist heavy ions of the R3B-FAIR experiment, as well as other applications. State-of-the-art reaction codes allow for evaluating the requirements of the detector. The specific needs that working with heavy ions impose about material thicknesses are solved with new design concepts. We built prototypes and investigated the behaviour of RPCs tested with relativistic heavy ions. We measured the efficiency and streamer presence for ions with atomic numbers up to 38. Electron beams were used to study the timing capabilities of the prototypes. (authors)

  14. A novel method for modeling the neutron time of flight (nTOF) detector response in current mode to inertial confinement fusion experiments.

    SciTech Connect

    Nelson, Alan J.; Cooper, Gary Wayne; Ruiz, Carlos L.; Chandler, Gordon Andrew; Fehl, David Lee; Hahn, Kelly Denise; Leeper, Ramon Joe; Smelser, Ruth Marie; Torres, Jose A.

    2013-09-01

    There are several machines in this country that produce short bursts of neutrons for various applications. A few examples are the Zmachine, operated by Sandia National Laboratories in Albuquerque, NM; the OMEGA Laser Facility at the University of Rochester in Rochester, NY; and the National Ignition Facility (NIF) operated by the Department of Energy at Lawrence Livermore National Laboratory in Livermore, California. They all incorporate neutron time of flight (nTOF) detectors which measure neutron yield, and the shapes of the waveforms from these detectors contain germane information about the plasma conditions that produce the neutrons. However, the signals can also be %E2%80%9Cclouded%E2%80%9D by a certain fraction of neutrons that scatter off structural components and also arrive at the detectors, thereby making analysis of the plasma conditions more difficult. These detectors operate in current mode - i.e., they have no discrimination, and all the photomultiplier anode charges are integrated rather than counted individually as they are in single event counting. Up to now, there has not been a method for modeling an nTOF detector operating in current mode. MCNPPoliMiwas developed in 2002 to simulate neutron and gammaray detection in a plastic scintillator, which produces a collision data output table about each neutron and photon interaction occurring within the scintillator; however, the postprocessing code which accompanies MCNPPoliMi assumes a detector operating in singleevent counting mode and not current mode. Therefore, the idea for this work had been born: could a new postprocessing code be written to simulate an nTOF detector operating in current mode? And if so, could this process be used to address such issues as the impact of neutron scattering on the primary signal? Also, could it possibly even identify sources of scattering (i.e., structural materials) that

  15. A highly-segmented ΔE-time-of-flight wall as forward detector of the 4π-system for charged particles at the SIS/ESR accelerator

    NASA Astrophysics Data System (ADS)

    Gobbi, A.; Alard, J. P.; Augustinski, G.; Basrak, Z.; Bastid, N.; Belayev, I. M.; Blaich, Th.; Boccaccio, P.; Bock, R.; Boussange, S.; Buta, A.; Čaplar, R.; Cerruti, C.; Charity, R. J.; Cindro, N.; Coffin, J. P.; Crouau, M.; Daudon, F.; Devin, J. F.; Dupieux, P.; Erö, J.; Fan, Z. G.; Fayard, C.; Fintz, P.; Fodor, Z.; Fraysse, L.; Freifelder, R.; Frolov, S.; Gimenez, E.; Grigorian, Y.; Guillaume, G.; Herrmann, N.; Hildenbrand, K. D.; Hölbling, S.; Hornecker, F.; Houari, A.; Jeong, S. C.; Jorio, M.; Jundt, F.; Kecskeméti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Krämer, M.; Kuhn, C.; Lebedev, A.; Legrand, I.; Maguire, C. F.; Manko, V.; Marquardt, M.; Matulewicz, T.; Mayade, S.; Mgebrishvili, G.; Mösner, J.; Moisa, D.; Montarou, G.; Montbel, I.; Morel, P.; Neubert, W.; Neunlist, R.; Ortlepp, G.; Pelte, D.; Petrovici, M.; Rami, F.; Reisdorf, W.; Saettel, M. A.; Sahuc, E.; Savinel, G.; Seres, Z.; Schüll, D.; Sikora, B.; Simion, V.; Smolyankin, S.; Sodan, U.; Tanaka, M. H.; Teh, K. M.; Tezkratt, R.; Tischler, B.; Trzaska, M.; Vasiliev, M. A.; Vincent, D.; Wagner, P.; Weinert, J.; Wessels, J. P.; Wienold, T.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A. V.

    1993-01-01

    At the SIS/ESR accelerator facility at GSI in Darmstadt the 4π-detector system FOPI is under construction at present. It is designed for the investigation of central collisions of heavy ions in the energy range up to 2 A GeV. As phase I of this detector a forward wall has been built and used in various experiments. It comprizes a total number of 764 scintillators with an additional shell of 188 thin ΔE-detectors in front of it and covers the full azimuth of the polar angles from 1° to 30°. The velocity and the nuclear charge of the fragments are determined by a combined time-of-flight and ΔE measurement.

  16. Test Beam Results for The Fast Interaction Trigger Detector of ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Powell, Calvin; Harton, Austin; Garcia-Solis, Edmundo; Alice-Fit Collaboration

    2016-09-01

    CERN (European Center for Nuclear Research) is a global laboratory that studies proton and heavy ion collisions at the Large Hadron Collider (LHC). ALICE (A Large Ion Collider Experiment) is one of four large experiments at the LHC. ALICE is dedicated to the study of the transition of matter to Quark-Gluon Plasma in heavy ion collisions. In the present ALICE detector, there are two sub-detectors, (the T0 and V0), that provide minimum bias trigger, multiplicity trigger, beam-gas event rejection, collision time for other sub-detectors, online multiplicity and event plane determination. In order to adapt these functionalities to the collision rates expected for the LHC upgrade after 2020, it is planned to replace these systems with a single system, called the Fast Interaction Trigger (FIT). In this poster we describe the FIT upgrade; show the proposed characteristics of the FIT detectors and present test beam performance results that support the current design parameters. This material is based upon work supported by the National Science Foundation under Grants NSF-PHY-1407051 and NSF-PHY-1305280.

  17. Time of flight mass spectrometer

    DOEpatents

    Ulbricht, Jr., William H.

    1984-01-01

    A time-of-flight mass spectrometer is described in which ions are desorbed from a sample by nuclear fission fragments, such that desorption occurs at the surface of the sample impinged upon by the fission fragments. This configuration allows for the sample to be of any thickness, and eliminates the need for complicated sample preparation.

  18. Recent resonance results measured with the ALICE detector at the LHC

    NASA Astrophysics Data System (ADS)

    Yalcin, Serpil; Uysal, Ayben Karasu

    2017-02-01

    Resonances are extremely short lived particles (τ ˜ 10-23 s). Due to their lifetime, they may decay, re-scatter and regenerate between chemical and kinetic freeze-outs. For this reason, they are very significant probes to understand the evolution of the medium and particle production mechanism in heavy ion collisions. Different than other particles, resonance properties such as mass, width and yield can be modified by the medium created in the relativistic collisions. Moreover, comparison of resonances produced in different collisions provide evidences about possible in medium effects and system size dependency of their production. ALICE (A Large Heavy Ion Experiment) is one of the detectors at the LHC specifically designed to investigate the features of the quark gluon plasma (QGP). In this proceeding, the recent ALICE resonance results in pp, p-Pb and Pb-Pb collisions at the LHC energies are presented.

  19. Proposal for Cherenkov Time of Flight Technique with Picosecond Resolution

    SciTech Connect

    S. Majewski; A. Margaryan; L. Tang

    2005-08-05

    A new particle identification device for Jlab 12 GeV program is proposed. It is based on the measurement of time information obtained by means of a new photon detector and time measuring concept. The expected time measurement precision for the Cherenkov time-of-flight detector is about or less than 10 picosecond for Cherenkov radiators with lengths less than 50 cm.

  20. High-dynamic-range neutron time-of-flight detector used to infer the D(t,n)(4)He and D(d,n)(3)He reaction yield and ion temperature on OMEGA.

    PubMed

    Forrest, C J; Glebov, V Yu; Goncharov, V N; Knauer, J P; Radha, P B; Regan, S P; Romanofsky, M H; Sangster, T C; Shoup, M J; Stoeckl, C

    2016-11-01

    Upgraded microchannel-plate-based photomultiplier tubes (MCP-PMT's) with increased stability to signal-shape linearity have been implemented on the 13.4-m neutron time-of-flight (nTOF) detector at the Omega Laser Facility. This diagnostic uses oxygenated xylene doped with diphenyloxazole C15H11NO + p-bis-(o-methylstyryl)-benzene (PPO + bis-MSB) wavelength shifting dyes and is coupled through four viewing ports to fast-gating MCP-PMT's, each with a different gain to allow one to measure the light output over a dynamic range of 1 × 10(6). With these enhancements, the 13.4-m nTOF can measure the D(t,n)(4)He and D(d,n)(3)He reaction yields and average ion temperatures in a single line of sight. Once calibrated for absolute neutron sensitivity, the nTOF detectors can be used to measure the neutron yield from 1 × 10(9) to 1 × 10(14) and the ion temperature with an accuracy approaching 5% for both the D(t,n)(4)He and D(d,n)(3)He reactions.

  1. High-dynamic-range neutron time-of-flight detector used to infer the D(t,n)4He and D(d,n)3He reaction yield and ion temperature on OMEGA

    NASA Astrophysics Data System (ADS)

    Forrest, C. J.; Glebov, V. Yu.; Goncharov, V. N.; Knauer, J. P.; Radha, P. B.; Regan, S. P.; Romanofsky, M. H.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C.

    2016-11-01

    Upgraded microchannel-plate-based photomultiplier tubes (MCP-PMT's) with increased stability to signal-shape linearity have been implemented on the 13.4-m neutron time-of-flight (nTOF) detector at the Omega Laser Facility. This diagnostic uses oxygenated xylene doped with diphenyloxazole C15H11NO + p-bis-(o-methylstyryl)-benzene (PPO + bis-MSB) wavelength shifting dyes and is coupled through four viewing ports to fast-gating MCP-PMT's, each with a different gain to allow one to measure the light output over a dynamic range of 1 × 106. With these enhancements, the 13.4-m nTOF can measure the D(t,n)4He and D(d,n)3He reaction yields and average ion temperatures in a single line of sight. Once calibrated for absolute neutron sensitivity, the nTOF detectors can be used to measure the neutron yield from 1 × 109 to 1 × 1014 and the ion temperature with an accuracy approaching 5% for both the D(t,n)4He and D(d,n)3He reactions.

  2. Reaching 200-ps timing resolution in a time-of-flight and depth-of-interaction positron emission tomography detector using phosphor-coated crystals and high-density silicon photomultipliers.

    PubMed

    Kwon, Sun Il; Ferri, Alessandro; Gola, Alberto; Berg, Eric; Piemonte, Claudio; Cherry, Simon R; Roncali, Emilie

    2016-10-01

    Current research in the field of positron emission tomography (PET) focuses on improving the sensitivity of the scanner with thicker detectors, extended axial field-of-view, and time-of-flight (TOF) capability. These create the need for depth-of-interaction (DOI) encoding to correct parallax errors. We have proposed a method to encode DOI using phosphor-coated crystals. Our initial work using photomultiplier tubes (PMTs) demonstrated the possibilities of the proposed method, however, a major limitation of PMTs for this application is poor quantum efficiency in yellow light, corresponding to the wavelengths of the converted light by the phosphor coating. In contrast, the red-green-blue-high-density (RGB-HD) silicon photomultipliers (SiPMs) have a high photon detection efficiency across the visible spectrum. Excellent coincidence resolving time (CRT; [Formula: see text]) was obtained by coupling RGB-HD SiPMs and [Formula: see text] lutetium fine silicate crystals coated on a third of one of their lateral sides. Events were classified in three DOI bins ([Formula: see text] width) with an average sensitivity of 83.1%. A CRT of [Formula: see text] combined with robust DOI encoding is a marked improvement in the phosphor-coated approach that we pioneered. For the first time, we read out these crystals with SiPMs and clearly demonstrated the potential of the RGB-HD SiPMs for this TOF-DOI PET detector.

  3. Development of a 10 picosecond time-of-flight Counter

    SciTech Connect

    Brandt, Andrew G

    2010-03-18

    This Advanced Detector Research proposal presented a plan to develop an extremely fast time-of-flight detector for measuring the arrival time of beam protons scattered at small angles in high energy hadron colliders, such as the Large Hadron Collider (LHC). The proposed detectors employ a gas or quartz Cerenkov radiator which produce light when a proton passes through them, coupled to a micro-channel plate photomultiplier tube (MCP-PMT) that converts the light to an electrical pulse. The very small jitter of the pulse time provided by the MCP-PMT, combined with downstream electronics that accurately measure the pulse time results in a time-of-flight measurement of unprecedented accuracy. This ADR proposal was extremely successful, culminating in the development of a 10 ps resolution time-of-flight system, about an order of magnitude better than any time-of-flight system previously deployed at a collider experiment. The primary areas of advance were the usage of new radiator geometries providing fast detector signals, using multiple measurements to obtain a superior system resolution, and development of an electronics readout system tuned to maintain the excellent timing afforded by the detector. Test beam and laser tests have improved the knowledge of MCP-PMT’s and enabled the evaluation of the new detector concepts. In addition to being a generally useful detector concept, these fast timing detectors are a major component of proposed upgrades to the LHC ATLAS and CMS detectors, and if deployed could significantly enhance the discovery potential of these detectors, including contributions to the measurement of the properties of the Higgs Boson. In addition to the potential for furthering fundamental understanding of nature, the knowledge gained on MCP-PMT’s could be useful in developing improved versions of these devices which have promise in diverse fields such as biological and medical imaging.

  4. Profiling of components of rhizoma et radix polygoni cuspidati by high-performance liquid chromatography with ultraviolet diode-array detector and ion trap/time-of-flight mass spectrometric detection

    PubMed Central

    Fu, Jinfeng; Wang, Min; Guo, Huimin; Tian, Yuan; Zhang, Zunjian; Song, Rui

    2015-01-01

    Introduction: Rhizoma et Radix Polygoni Cuspidati (Huzhang in Chinese, HZ) is a traditional medicinal plant in China. Many of the components of HZ have been proved to be bioactive while it is difficult to conduct a comprehensive chemical profiling of HZ as a consequence of the absence of efficient separation system and sensitive detective means. We developed a simple and effective method for comprehensive characterization of constituents in HZ. Objective: To develop a simple and effective method to characterize the components in HZ and provide useful information for subsequent metabolic studies of HZ. Materials and Methods: The components in HZ aqueous extract were characterized by using high performance liquid chromatography with UV diode-array detector (HPLC-DAD) and ion trap/time-of-flight mass spectrometric detection (HPLC-IT/TOF). Stilbenes, anthraquinones, gallates and tannins, naphthalenes and some other compounds were identified and confirmed by diagnostic fragment ions with accurate mass measurements, characteristic fragmentation pathways and relevant published literatures. Results: Among the 238 constituents detected in HZ, a total number of 74 constituents were identified unambiguously or tentatively, including 29 compounds reported for the first time in HZ. Conclusion: The identification and structure elucidation of these chemicals provided essential data for quality control and further in vivo metabolic studies of HZ. Key words: Polygonum cuspidatum, HPLC-DAD, HPLC-IT/TOF, qualitative analysis. PMID:26246723

  5. Rapid Identification and Simultaneous Quantification of Multiple Constituents in Nao-Shuan-Tong Capsule by Ultra-Fast Liquid Chromatography/Diode-Array Detector/Quadrupole Time-of-Flight Tandem Mass Spectrometry.

    PubMed

    Li, Panlin; Su, Weiwei; Xie, Chengshi; Zeng, Xuan; Peng, Wei; Liu, Menghua

    2015-07-01

    A rapid and high-sensitive ultra-fast liquid chromatography coupled with a diode-array detector and a quadrupole/time-of-flight mass spectrometry (MS) method was established and validated for the chemical profiling of Nao-shuan-tong capsule (NSTC) and simultaneous quantification of five major constituents. A total of 59 components including monoterpene glycosides, flavonoids, sesquiterpenoids, ketosteroids, thiophenes, organic acids and alkaloids were identified or tentatively characterized in NSTC based on the accurate mass and tandem MS behavior. Five major bioactive constituents were chosen as the chemical indexes of holistic quality evaluation and quantified simultaneously. All calibration curves showed good linear regression (r(2) > 0.9991) in the range 25.2-510, 145-2,900, 1.84-36.8, 2.61-52.2 and 3.25-26.2 μg/mL for gastrodin, paeoniflorin, typhaneoside, β-ecdysterone and isorhamnetin-3-O-neohesperidoside, respectively. It also showed good precision, stability and accuracy for quantification of these five compounds. The limit of detections and limit of quantitations for the analytes ranged from 0.14 to 1.09 μg/mL and from 0.47 to 3.63 μg/mL, respectively. The validated quantification method was applied to analyze 10 batches of commercial NSTC. These results will provide a basis for quality control of the production process and the further pharmacological study in vivo of NSTC.

  6. Evaluation of a pulsed glow discharge time-of-flight mass spectrometer as a detector for gas chromatography and the influence of the glow discharge source parameters on the information volume in chemical speciation analysis.

    PubMed

    Fliegel, Daniel; Fuhrer, Katrin; Gonin, Marc; Günther, Detlef

    2006-09-01

    The figures of merit of a pulsed glow discharge time-of-flight mass spectrometer (GD-TOFMS) as a detector for gas chromatography (GC) analysis were evaluated. The mass resolution for the GD-TOFMS was determined on FWHM in the high mass range (208Pb+) as high as 5,500. Precision of 400 subsequent analyses was calculated on 63Cu+ to be better than 1% RSD with no significant drift over the time of the analysis. Isotope precision based on the 63Cu+/65Cu+ ratio over 400 analyses was 1.5% RSD. The limits of detection for gaseous analytes (toluene in methanol as solvent) were determined to be as low as several hundred ppb or several hundred pg absolute without using any pre-concentration technique. Furthermore, the different GD source parameters like capillary distance, cathode-anode spacing, and GD source pressure with regards to the accessible elemental, structural, and molecular information were evaluated. It was demonstrated that each of these parameters has severe influence on the ratio of elemental, structural, and parent molecular information in chemical speciation analysis.

  7. Analysis and improved characterization of minor antioxidants from leaves of Malus doumeri using a combination of major constituents' knockout with high-performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry.

    PubMed

    Zhao, Huading; Hu, Xin; Chen, Xiaoqin; Shi, Shuyun; Jiang, Xinyu; Liang, Xuejuan; Chen, Wei; Zhang, Shuihan

    2015-06-12

    Due to the complexity of natural products, efficient identification of bioactive compounds, especially for minor compounds, would require a huge effort. Here, we developed an effective strategy based on combining major constituents' knockout with high-performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry (HPLC-DAD-QTOF-MS/MS) to comprehensively identify minor antioxidants in Malus doumeri, one of the longest known and most used tonic plant in Taiwan. First, five major compounds (I-V) in M. doumeri were knocked out by two-step stepwise high-speed countercurrent chromatography (HSCCC). Second, minor antioxidants were screened by 1,1-diphenyl-2-picrylhydrazyl radical-HPLC (DPPH-HPLC) assay. Third, structures of thirty minor antioxidants, including 11 dihydrochalcones, 4 flavanones, 3 flavonols, 2 flavones, 3 aurones and 7 phenolic acids, were unambiguously or tentatively identified by matching their characteristic UV spectra, accurate mass signals and key diagnostic fragment ions with standards or previously reported compounds. Twenty-six of them, as far as was known, were discovered from M. doumeri for the first time. The results indicated that the proposed method was a useful approach to explore minor bioactive compounds from complex natural products.

  8. Time-of-flight measurements

    SciTech Connect

    Atwood, W.B.

    1980-10-01

    Time of flight (TOF) measurements are used in high energy particle physics experiments to: (1) distinguish background from events and (2) identify particle types. An example of background separation is shown. These data come from a coincidence electro-production experiment performed at SLAC. The reaction being studied was e + p ..-->.. e' + p' + X where the e(p) stand for an initial and detected electron (proton) and X is a produced but undetected final state with a mass in the rho meson region. The relative time between the detection of an electron and a proton in two of the spectrometers in End Station A is plotted. Data for two different kinematic settings taken in the experiment are shown. The time resolution has been partially corrected for the various flight paths through the instruments and the difference in time resolutions between the two settings results mainly from the incompleteness of this correction. The signal height above the background depends on the time resolution, ..delta.. tau. The chance background is proportional to the product of the electron counting rate, the proton counting rate, and ..delta.. tau. Smaller ..delta.. tau means that higher electron and proton counting rates may be tolerated and result in a similar signal-to-noise ratio.

  9. Very high Momentum Particle Identification detector for ALICE at the LHC

    SciTech Connect

    Garcia, Edmundo

    2009-04-20

    The anomalies observed at RHIC for the baryon-meson ratios have prompted a number of theoretical works on the nature of the hadrochemistry in the hadronisation stage of the pp collisions and in the evolution of the dense system formed in heavy ion collisions. Although the predictions differ in the theoretical approach, generally a substantial increase in the baryon production is predicted in the range 10-30 GeV/c. This raises the problem of baryon identification to much higher momenta than originally planned in the LHC experiments. After a review of the present status of theoretical predictions we will present the possibilities of a gas ring imaging Cherenkov detector of limited acceptance which would be able to identify track-by-track protons until 26 GeV/c. The physics capabilities of such a detector in conjunction with the ALICE experiment will be contemplated as well as the triggering options to enrich the sample of interesting events with a dedicated trigger or/and using the ALICE Electromagnetic Calorimeter. The use of the electromagnetic calorimeter opens interesting possibility to distinguish quark and gluon jets in gamma--jet events and subsequently the study of the probability of fragmentation in proton, kaon and pion or triggering on jets in the EMCAL. Such a detector would be identify pions until 14 GeV/c kaons from 9 till 14 GeV/c and protons from 18 till 24/GeV/c in a positive way and by absence of signal from 9-18 GeV/c.

  10. Simultaneous qualitative and quantitative determination of phenolic compounds in Aloe barbadensis Mill by liquid chromatography-mass spectrometry-ion trap-time-of-flight and high performance liquid chromatography-diode array detector.

    PubMed

    Wu, Xiaofang; Ding, Wenjing; Zhong, Jiasheng; Wan, Jinzhi; Xie, Zhiyong

    2013-06-01

    An effective and comprehensive method was developed for the simultaneous analysis of phenolic compounds in the dried exudate of Aloe barbadensis Mill by liquid chromatography-mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF) and high performance liquid chromatography-diode array detector (HPLC-DAD). Qualitative analysis of all the compounds presented in A. barbadensis Mill was performed on LCMS-IT-TOF, and the diagnostic fragmentation patterns of different types of phenolic compounds (chromones, phenyl pyrones, naphthalene derivative, anthrones and anthraquinones) were discussed on the basis of ESI-IT-TOF MS of components in A. barbadensis Mill and eleven authentic standards. Under the optimal HPLC-DAD chromatographic conditions, quantification of 11 typical phenolic compounds in 15 batches of A. barbadensis Mill was achieved on an Agilent TC-C18 column using gradient elution with a solvent system of methanol and water at a flow rate of 1.0mLmin(-1) and detected at 230nm. All calibration curves exhibited good linear relationship (r(2)>0.9991). The relative standard deviation values for intraday precision were less than 2% with accuracies between 98.21% and 104.57%. The recoveries of the eleven analytes ranged from 97.53 to 105.00% with RSDs less than 2%. This is the first simultaneous characterization and quantitative determination of multiple phenolic compounds in A. barbadensis Mill from locally grown cultivars in China by LCMS-IT-TOF and HPLC-DAD, which can be applied to standardize the quality of A. barbadensis Mill and the future design of nutraceutical and cosmetic preparations.

  11. Quantitative analysis of nitrogen containing compounds in microalgae based bio-oils using comprehensive two-dimensional gas-chromatography coupled to nitrogen chemiluminescence detector and time of flight mass spectrometer.

    PubMed

    Toraman, Hilal E; Franz, Kristina; Ronsse, Frederik; Van Geem, Kevin M; Marin, Guy B

    2016-08-19

    Insight in the composition of the algae derived bio-oils is crucial for the development of efficient conversion processes and better upgrading strategies for microalgae. Comprehensive two-dimensional gas chromatography (GC×GC) coupled to nitrogen chemiluminescence detector (NCD) and time-of-flight mass spectrometer (TOF-MS) allows to obtain the detailed quantitative composition of the nitrogen containing compounds in the aqueous and the organic fraction of fast pyrolysis bio-oils from microalgae. Normal phase (apolar×mid-polar) and reverse phase column (polar×apolar) combination are investigated to optimize the separation of the detected nitrogen containing compounds. The reverse phase column combination gives the most detailed information in terms of the nitrogen containing compounds. The combined information from the GC×GC-TOF-MS (qualitative) and GC×GC-NCD (quantitative) with the use of a well-chosen internal standard, i.e. caprolactam, enables the identification and quantification of nitrogen containing compounds belonging to 13 different classes: amines, imidazoles, amides, imides, nitriles, pyrazines, pyridines, indoles, pyrazoles, pyrimidines, quinolines, pyrimidinediones and other nitrogen containing compounds which were not assigned to a specific class. The aqueous fraction mostly consists of amines (4.0wt%) and imidazoles (2.8wt%) corresponding to approximately 80wt% of the total identified nitrogen containing compounds. On the other hand, the organic fraction shows a more diverse distribution of nitrogen containing compounds with the majority of the compounds quantified as amides (3.0wt%), indoles (2.0wt%), amines (1.7wt%) and imides (1.3wt%) corresponding to approximately 65wt% of the total identified nitrogen containing compounds.

  12. Sensitive characterization of polyphenolic antioxidants in Polygonatum odoratum by selective solid phase extraction and high performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry.

    PubMed

    Hu, Xin; Zhao, Huading; Shi, Shuyun; Li, Hui; Zhou, Xiaoling; Jiao, Feipeng; Jiang, Xinyu; Peng, Dongming; Chen, Xiaoqin

    2015-08-10

    The complexity of natural products always leads to the co-elution of interfering compounds with bioactive compounds, which then has a detrimental effect on structural elucidation. Here, a new method, based on selective solid phase extraction combined with 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) spiking and high performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry (HPLC-DAD-QTOF-MS/MS), is described for sensitive screening, selective extraction and identification of polyphenolic antioxidants in Polygonatum odoratum. First, 25 polyphenolic antioxidants (1-25) were screened by DPPH spiking with HPLC. Second, polydopamine coated Fe3O4 microspheres (Fe3O4@PDA) were prepared to selectively extract target antioxidants with extraction efficiency from 55% to 100% when the amount of Fe3O4@PDA, extraction time, desorption solvent and time were 10mg, 20 min, acetonitrile, and 5 min. Third, 25 antioxidants (10 cinnamides and 15 homoisoflavanones) were identified by HPLC-DAD-QTOF-MS/MS. Furthermore, the DPPH scavenging activities of purified compounds (IC50, 1.6-32.8 μg/mL) validated the method. Among the identified antioxidants, four of them (12, 13, 18 and 19) were new compounds, four of them (2, 4, 8 and 14) were first obtained from family Liliaceae, five of them (1, 3, 5, 7 and 9) were first reported in genus Polygonatum, while one compound (24) was first identified in this species. The results indicated that the proposed method was an efficient and sensitive approach to explore polyphenolic antioxidants from complex natural products.

  13. Inexpensive Time-of-Flight Velocity Measurements.

    ERIC Educational Resources Information Center

    Everett, Glen E.; Wild, R. L.

    1979-01-01

    Describes a circuit designed to measure time-of-flight velocity and shows how to use it to determine bullet velocity in connection with the ballistic pendulum demonstration of momentum conservation. (Author/GA)

  14. Charged particle production in Pb-Pb collisions at the LHC with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Floris, M.

    2013-08-01

    The ALICE collaboration measured charged particle production in √{sNN} = 2.76 TeV Pb-Pb collisions at the LHC. We report on results on charged particle multiplicity and transverse momentum spectra. All the results are presented as a function of the centrality of the collision, estimated with a Glauber Monte Carlo fit to multiplicity distributions reconstructed in various detectors. The applicability of the Glauber model at LHC energies, the precision of the centrality determination and the related systematic uncertainties are discussed in detail. Particles are tracked in the pseudorapidity window | η | ≲ 0.9 with the silicon Inner Tracking System (ITS) and the Time Projection Chamber (TPC), over the range 0.15

  15. Compensated time of flight telescope for spaceborne cosmic ray measurements

    NASA Technical Reports Server (NTRS)

    Rothermel, H.

    1977-01-01

    A large area time-of-flight telescope has been studied for future application in space-borne cosmic ray experiments. A new compensation technique for propagation delays inside the scintillators has been applied, which is operative in two perpendicular directions. This technique, superior to conventional one-dimensional compensations, allows high rejection probability for upward moving single particles at very short counter distances. Besides mechanical advantages a short counter distance is desirable because it permits a large field of view for the detector. A measurement of light transit times in scintillators is presented and based on it, directionality for shower events is discussed.

  16. The Time-of-Flight trigger at CDF

    SciTech Connect

    Bauer, G.; Mulhearn, M.J.; Paus, Ch.; Schieferdecker, P.; Tether, S.; Lewis, J.D.; Shaw, T.; Acosta, D.; Konigsberg, J.; Madorsky, A.; /Florida U.

    2006-05-01

    The Time-of-Flight (TOF) detector measures the arrival time and deposited energy of charged particles reaching scintillator bars surrounding the central tracking region of the CDF detector. Requiring high ionization in the TOF system provides a unique trigger capability, which has been used for a magnetic monopole search. Other uses, with smaller pulse height thresholds, include a high-multiplicity charged-particle trigger useful for QCD studies and a much improved cosmic ray trigger for calibrating other detector components. Although not designed as input to CDF's global Level 1 trigger, the TOF system has been easily adapted to this role by the addition of 24 cables, new firmware, and four custom TOF trigger boards (TOTRIBs). This article describes the TOF trigger.

  17. Time-of-flight radio location system

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence.

  18. Time-of-flight radio location system

    DOEpatents

    McEwan, T.E.

    1996-04-23

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. 7 figs.

  19. Implementation of the final geometry of the V0A detector for the ALICE experiment in the simulator program AliRoot

    SciTech Connect

    Valencia, L.

    2008-07-02

    The V0A trigger detector of the ALICE experiment is a scintillator hodoscope of 32 channels that has been designed and constructed by the Mexican groups at the Instituto de Fisica de la UNAM and the CINVESTAV.In this work, the final geometry of the constructed detector and its support frame have been implemented using the geometrical modeler of the Root framework in order to be able to simulate the response and trigger performance of the detector with AliRoot.

  20. Miniature Focusing Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Kanik, Isik; Srivastava, Santosh

    2005-01-01

    -particle detector. The output of the detector is fed to a counting circuit to obtain data on the counting rate as a function of time. Inasmuch as time of flight is directly proportional to the ion mass, a plot of the counting rate versus time of flight is equivalent to a mass spectrum (see Figure 2).

  1. Avalanche photodiode based time-of-flight mass spectrometry

    SciTech Connect

    Ogasawara, Keiichi Livi, Stefano A.; Desai, Mihir I.; Ebert, Robert W.; McComas, David J.; Walther, Brandon C.

    2015-08-15

    This study reports on the performance of Avalanche Photodiodes (APDs) as a timing detector for ion Time-of-Flight (TOF) mass spectroscopy. We found that the fast signal carrier speed in a reach-through type APD enables an extremely short timescale response with a mass or energy independent <2 ns rise time for <200 keV ions (1−40 AMU) under proper bias voltage operations. When combined with a microchannel plate to detect start electron signals from an ultra-thin carbon foil, the APD comprises a novel TOF system that successfully operates with a <0.8 ns intrinsic timing resolution even using commercial off-the-shelf constant-fraction discriminators. By replacing conventional total-energy detectors in the TOF-Energy system, APDs offer significant power and mass savings or an anti-coincidence background rejection capability in future space instrumentation.

  2. Time-of-flight radio location system

    DOEpatents

    McEwan, Thomas E.

    1997-01-01

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. The sample signal in equivalent time is passed through an envelope detection circuit, formed of an absolute value circuit followed by a low pass filter, to convert the sample signal to a unipolar signal to eliminate effects of antenna misorientation.

  3. Time-of-flight radio location system

    DOEpatents

    McEwan, T.E.

    1997-08-26

    A bi-static radar configuration measures the direct time-of-flight of a transmitted RF pulse and is capable of measuring this time-of-flight with a jitter on the order of about one pico-second, or about 0.01 inch of free space distance for an electromagnetic pulse over a range of about one to ten feet. A transmitter transmits a sequence of electromagnetic pulses in response to a transmit timing signal, and a receiver samples the sequence of electromagnetic pulses with controlled timing in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the sequence of electromagnetic pulses such that the time between transmission of pulses in the sequence and sampling by the receiver sweeps over a range of delays. The receive timing signal sweeps over the range of delays in a sweep cycle such that pulses in the sequence are sampled at the pulse repetition rate, and with different delays in the range of delays to produce a sample signal representing magnitude of a received pulse in equivalent time. Automatic gain control circuitry in the receiver controls the magnitude of the equivalent time sample signal. A signal processor analyzes the sample signal to indicate the time-of-flight of the electromagnetic pulses in the sequence. The sample signal in equivalent time is passed through an envelope detection circuit, formed of an absolute value circuit followed by a low pass filter, to convert the sample signal to a unipolar signal to eliminate effects of antenna misorientation. 8 figs.

  4. Time-of-flight Fourier UCN spectrometer

    NASA Astrophysics Data System (ADS)

    Kulin, G. V.; Frank, A. I.; Goryunov, S. V.; Kustov, D. V.; Geltenbort, P.; Jentschel, M.; Lauss, B.; Schmidt-Wellenburg, P.

    2016-05-01

    We describe a new time-of-flight Fourier spectrometer for investigation of UCN diffraction by a moving grating. The device operates in the regime of a discrete set of modulation frequencies. The results of the first experiments show that the spectrometer may be used for obtaining UCN energy spectra in the energy range of 60 - 200 neV with a resolution of about 5 neV. The accuracy of determination of the line position was estimated to be several units of 10-10 eV.

  5. Detection system for high-resolution gamma radiation spectroscopy with neutron time-of-flight filtering

    DOEpatents

    Dioszegi, Istvan; Salwen, Cynthia; Vanier, Peter

    2014-12-30

    A .gamma.-radiation detection system that includes at least one semiconductor detector such as HPGe-Detector, a position-sensitive .alpha.-Detector, a TOF Controller, and a Digitizer/Integrator. The Digitizer/Integrator starts to process the energy signals of a .gamma.-radiation sent from the HPGe-Detector instantly when the HPGe-Detector detects the .gamma.-radiation. Subsequently, it is determined whether a coincidence exists between the .alpha.-particles and .gamma.-radiation signal, based on a determination of the time-of-flight of neutrons obtained from the .alpha.-Detector and the HPGe-Detector. If it is determined that the time-of-flight falls within a predetermined coincidence window, the Digitizer/Integrator is allowed to continue and complete the energy signal processing. If, however, there is no coincidence, the Digitizer/Integrator is instructed to be clear and reset its operation instantly.

  6. (Multi-)strange hadron and light (anti-)nuclei production with ALICE at the LHC

    SciTech Connect

    Lea, Ramona

    2016-01-22

    Thanks to its excellent tracking performance and particle identification capabilities, the ALICE detector allows for the identification of light (anti-)(hyper)nuclei and for the measurement of (multi-)strange particles over a wide range of transverse momentum. Deuterons, {sup 3}He and {sup 4}He and their corresponding anti-nuclei are identified via their specific energy loss in the Time Projection Chamber and the velocity measurement provided by the Time-Of-Flight detector. Strange and multi-strange baryons and mesons as well as (anti-)hypertritons are reconstructed via their topological decays. Detailed measurements of (multi-)strange hadron production in pp, p–Pb and Pb–Pb collision and of light (anti-)nuclei and (anti-)hypertritons in Pb–Pb collisions with ALICE at the LHC are presented. The experimental results will be compared with the predictions of both statistical hadronization and coalescence models.

  7. Study of muon bundles from extensive air showers with the ALICE detector at CERN LHC

    NASA Astrophysics Data System (ADS)

    Shtejer, K.

    2016-05-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic-ray interactions in the upper atmosphere. The large size and excellent tracking capability of the ALICE Time Projection Chamber are exploited to study the muonic component of extensive air showers. We present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. The latest version of the QGSJET hadronic interaction model was used to simulate the development of the resulting air showers. High multiplicity events containing more than 100 reconstructed muons were also studied. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP without satisfactory explanations for the frequency of the highest multiplicity events. We demonstrate that the high muon-multiplicity events observed in ALICE stem from primary cosmic rays with energies above 1016 eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range.

  8. Time of flight system on a chip

    NASA Technical Reports Server (NTRS)

    Paschalidis, Nicholas P. (Inventor)

    2006-01-01

    A CMOS time-of-flight TOF system-on-a-chip SoC for precise time interval measurement with low power consumption and high counting rate has been developed. The analog and digital TOF chip may include two Constant Fraction Discriminators CFDs and a Time-to-Digital Converter TDC. The CFDs can interface to start and stop anodes through two preamplifiers and perform signal processing for time walk compensation (110). The TDC digitizes the time difference with reference to an off-chip precise external clock (114). One TOF output is an 11-bit digital word and a valid event trigger output indicating a valid event on the 11-bit output bus (116).

  9. Time-of-Flight Microwave Camera.

    PubMed

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-10-05

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable "stealth" regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows "camera-like" behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum.

  10. Miniature Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Potember, Richard S.

    1999-01-01

    Major advances must occur to protect astronauts from prolonged periods in near-zero gravity and high radiation associated with extended space travel. The dangers of living in space must be thoroughly understood and methods developed to reverse those effects that cannot be avoided. Six of the seven research teams established by the National Space Biomedical Research Institute (NSBRI) are studying biomedical factors for prolonged space travel to deliver effective countermeasures. To develop effective countermeasures, each of these teams require identification of and quantitation of complex pharmacological, hormonal, and growth factor compounds (biomarkers) in humans and in experimental animals to develop an in-depth knowledge of the physiological changes associated with space travel. At present, identification of each biomarker requires a separate protocol. Many of these procedures are complicated and the identification of each biomarker requires a separate protocol and associated laboratory equipment. To carry all of this equipment and chemicals on a spacecraft would require a complex clinical laboratory; and it would occupy much of the astronauts time. What is needed is a small, efficient, broadband medical diagnostic instrument to rapidly identify important biomarkers for human space exploration. The Miniature Time-Of- Flight Mass Spectrometer Project in the Technology Development Team is developing a small, high resolution, time-of-flight mass spectrometer (TOFMS) to quantitatively measure biomarkers for human space exploration. Virtues of the JHU/APL TOFMS technologies reside in the promise for a small (less than one cubic ft), lightweight (less than 5 kg), low-power (less than 50 watts), rugged device that can be used continuously with advanced signal processing diagnostics. To date, the JHU/APL program has demonstrated mass capability from under 100 to beyond 10,000 atomic mass units (amu) in a very small, low power prototype for biological analysis. Further

  11. Miniaturised Time-of-Flight Mass Spectrometer

    NASA Astrophysics Data System (ADS)

    Rohner, U.; Benz, W.; Whitby, J. A.; Wurz, P.; Schulz, R.; Romstedt, J.

    2004-04-01

    Originally intended for the European Space Agency's BepiColombo mission to Mercury, we have built a series of highly miniaturised laser ablation time of flight mass spectrometers (LMS), suitable for in situ measurements of the elemental and isotopic composition of the surface of airless planetary bodies. The instruments will determine ma jor, minor, and trace element abundances in minerals on a spatial scale of 10 m, and will have sufficient dynamic range and mass resolution to perform useful isotopic measurements in favourable cases. Solid material is simultaneously evaporated and ionised by means of laser ablation, requiring intense pulsed laser radiation. Laser ablation was chosen as the sample introduction technique principally because of its high spatial resolution and the lack of any need for sample preparation. Advantages of the technique include simplicity of the resulting design, speed of measurement, and the ability for depth profiling (potentially important for a regolith in which mineral grains are coated with impact produced glass). Time of flight mass spectrometers are simple, robust devices that couple well to a pulsed ion source and we have previous experience of their construction for space flight, e.g. the ROSINA instrument suite for the ROSETTA mission. For BepiColombo, we have built two prototype instruments, one with a design mass of 500 g and a volume comparable to a beer can intended to be deployed on a static lander, and a smaller cigarettebox sized version with a design mass of 250 g, small enough to be integrated in a rover or robotic arm.

  12. Linear electronic field time-of-flight ion mass spectrometers

    DOEpatents

    Funsten, Herbert O.

    2010-08-24

    Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent atomic ions and emits secondary electrons; an electrode which produces secondary electrons upon contact with a constituent atomic ion in second drift region; a stop detector comprising a first ion detection region and a second ion detection region; and a timing means connected to the pulsed ionization source, to the first ion detection region, and to the second ion detection region.

  13. Highly charged ion based time of flight emission microscope

    DOEpatents

    Barnes, Alan V.; Schenkel, Thomas; Hamza, Alex V.; Schneider, Dieter H.; Doyle, Barney

    2001-01-01

    A highly charged ion based time-of-flight emission microscope has been designed, which improves the surface sensitivity of static SIMS measurements because of the higher ionization probability of highly charged ions. Slow, highly charged ions are produced in an electron beam ion trap and are directed to the sample surface. The sputtered secondary ions and electrons pass through a specially designed objective lens to a microchannel plate detector. This new instrument permits high surface sensitivity (10.sup.10 atoms/cm.sup.2), high spatial resolution (100 nm), and chemical structural information due to the high molecular ion yields. The high secondary ion yield permits coincidence counting, which can be used to enhance determination of chemical and topological structure and to correlate specific molecular species.

  14. Advances in time-of-flight PET

    PubMed Central

    Surti, Suleman; Karp, Joel S.

    2016-01-01

    This paper provides a review and an update on time-of-flight PET imaging with a focus on PET instrumentation, ranging from hardware design to software algorithms. We first present a short introduction to PET, followed by a description of TOF PET imaging and its history from the early days. Next, we introduce the current state-of-art in TOF PET technology and briefly summarize the benefits of TOF PET imaging. This is followed by a discussion of the various technological advancements in hardware (scintillators, photo-sensors, electronics) and software (image reconstruction) that have led to the current widespread use of TOF PET technology, and future developments that have the potential for further improvements in the TOF imaging performance. We conclude with a discussion of some new research areas that have opened up in PET imaging as a result of having good system timing resolution, ranging from new algorithms for attenuation correction, through efficient system calibration techniques, to potential for new PET system designs. PMID:26778577

  15. Time-of-Flight Microwave Camera

    PubMed Central

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-01-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable “stealth” regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz–12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows “camera-like” behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum. PMID:26434598

  16. Time-of-Flight Microwave Camera

    NASA Astrophysics Data System (ADS)

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-10-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable “stealth” regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows “camera-like” behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum.

  17. Combined distance-of-flight and time-of-flight mass spectrometer

    DOEpatents

    Enke, Christie G; Ray, Steven J; Graham, Alexander W; Hieftje, Gary M; Barinaga, Charles J; Koppenaal, David W

    2014-02-11

    A combined distance-of-flight mass spectrometry (DOFMS) and time-of-flight mass spectrometry (TOFMS) instrument includes an ion source configured to produce ions having varying mass-to-charge ratios, a first detector configured to determine when each of the ions travels a predetermined distance, a second detector configured to determine how far each of the ions travels in a predetermined time, and a detector extraction region operable to direct portions of the ions either to the first detector or to the second detector.

  18. A new, highly sensitive time-of-flight mass spectrometer consisting of a flangeon-type conical ion lens system and a proto-type Daly detector for exhaust gas analysis based on the Jet-REMPI technique.

    PubMed

    Suzuki, Tetsuya; Hayashi, Shun-ichi; Ishiuchi, Shun-ichi; Saeki, Morihisa; Fujii, Masaaki

    2005-08-01

    For the analysis of trace amounts of hazardous organic compounds, we developed a new ion detection system for supersonic jet resonance-enhanced multiphoton laser ionization mass spectrometry. High sensitivity and selectivity have been achieved by combining a proto-type Daly detector, a newly designed conical ion lens, and a potential switch that can perform the function of a mass selector. This ion detection system enables us to bring the jet nozzle closer to the ionization point. The detection sensitivity has thus been improved totally by more than 100 times compared with that obtained by the parallel-plate electrodes and micro-channel plate. We succeeded in assembling a flangeon-type ion extraction electrode consisting of a conical ion lens and a potential switch.

  19. Particle identification in ALICE: a Bayesian approach

    NASA Astrophysics Data System (ADS)

    Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Aiola, S.; Akindinov, A.; Alam, S. N.; Albuquerque, D. S. D.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaraz, J. R. M.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arnaldi, R.; Arnold, O. W.; Arsene, I. C.; Arslandok, M.; Audurier, B.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Balasubramanian, S.; Baldisseri, A.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Barth, K.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Benacek, P.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biro, G.; Biswas, R.; Biswas, S.; Bjelogrlic, S.; Blair, J. T.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botta, E.; Bourjau, C.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Butt, J. B.; Buxton, J. T.; Cabala, J.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Carnesecchi, F.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Cerkala, J.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chauvin, A.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Cho, S.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danisch, M. C.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Conti, C.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; Deplano, C.; Dhankher, P.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Drozhzhova, T.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Endress, E.; Engel, H.; Epple, E.; Erazmus, B.; Erdemir, I.; Erhardt, F.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Feuillard, V. J. G.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fronze, G. G.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Gauger, E. F.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; Gonzalez, A. S.; Gonzalez, V.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Grachov, O. A.; Graczykowski, L. K.; Graham, K. L.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gronefeld, J. M.; Grosse-Oetringhaus, J. F.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamon, J. C.; Harris, J. W.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Hellbär, E.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hillemanns, H.; Hippolyte, B.; Horak, D.; Hosokawa, R.; Hristov, P.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Inaba, M.; Incani, E.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacazio, N.; Jacobs, P. M.; Jadhav, M. B.; Jadlovska, S.; Jadlovsky, J.; Jahnke, C.; Jakubowska, M. J.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karayan, L.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Mohisin Khan, M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, D. W.; Kim, D. J.; Kim, D.; Kim, H.; Kim, J. S.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Klewin, S.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kopcik, M.; Kostarakis, P.; Kour, M.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Koyithatta Meethaleveedu, G.; Králik, I.; Kravčáková, A.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kuhn, C.; Kuijer, P. G.; Kumar, A.; Kumar, J.; Kumar, L.; Kumar, S.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Ladron de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, G. R.; Lee, S.; Lehas, F.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; León Vargas, H.; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Luettig, P.; Lunardon, M.; Luparello, G.; Lutz, T. H.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Martin Blanco, J.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; Mcdonald, D.; Meddi, F.; Melikyan, Y.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Moreira De Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Mulligan, J. D.; Munhoz, M. G.; Munzer, R. H.; Murakami, H.; Murray, S.; Musa, L.; Musinsky, J.; Naik, B.; Nair, R.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Natal da Luz, H.; Nattrass, C.; Navarro, S. R.; Nayak, K.; Nayak, R.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Noris, J. C. C.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Orava, R.; Oravec, M.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, D.; Pagano, P.; Paić, G.; Pal, S. K.; Pan, J.; Pandey, A. K.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Patra, R. N.; Paul, B.; Pei, H.; Peitzmann, T.; Pereira Da Costa, H.; Peresunko, D.; Pérez Lara, C. E.; Perez Lezama, E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pimentel, L. O. D. L.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Rami, F.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Read, K. F.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Saarinen, S.; Sadhu, S.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sano, M.; Sarkar, D.; Sarkar, N.; Sarma, P.; Scapparone, E.; Scarlassara, F.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Šefčík, M.; Seger, J. E.; Sekiguchi, Y.; Sekihata, D.; Selyuzhenkov, I.; Senosi, K.; Senyukov, S.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shahzad, M. I.; Shangaraev, A.; Sharma, A.; Sharma, M.; Sharma, M.; Sharma, N.; Sheikh, A. I.; Shigaki, K.; Shou, Q.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Souza, R. D. de; Sozzi, F.; Spacek, M.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Stachel, J.; Stan, I.; Stankus, P.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Suljic, M.; Sultanov, R.; Šumbera, M.; Sumowidagdo, S.; Szabo, A.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Tabassam, U.; Takahashi, J.; Tambave, G. J.; Tanaka, N.; Tarhini, M.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thakur, D.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trombetta, G.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vechernin, V.; Veen, A. M.; Veldhoen, M.; Velure, A.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Watanabe, D.; Watanabe, Y.; Weber, M.; Weber, S. G.; Weiser, D. F.; Wessels, J. P.; Westerhoff, U.; Whitehead, A. M.; Wiechula, J.; Wikne, J.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yang, H.; Yang, P.; Yano, S.; Yasin, Z.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yoon, J. H.; Yurchenko, V.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zardoshti, N.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhang, C.; Zhang, Z.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.

    2016-05-01

    We present a Bayesian approach to particle identification (PID) within the ALICE experiment. The aim is to more effectively combine the particle identification capabilities of its various detectors. After a brief explanation of the adopted methodology and formalism, the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE is studied. PID is performed via measurements of specific energy loss ( d E/d x) and time of flight. PID efficiencies and misidentification probabilities are extracted and compared with Monte Carlo simulations using high-purity samples of identified particles in the decay channels K0S → π-π+, φ→ K-K+, and Λ→ p π- in p-Pb collisions at √{s_{NN}}=5.02 TeV. In order to thoroughly assess the validity of the Bayesian approach, this methodology was used to obtain corrected pT spectra of pions, kaons, protons, and D0 mesons in pp collisions at √{s}=7 TeV. In all cases, the results using Bayesian PID were found to be consistent with previous measurements performed by ALICE using a standard PID approach. For the measurement of D0 → K-π+, it was found that a Bayesian PID approach gave a higher signal-to-background ratio and a similar or larger statistical significance when compared with standard PID selections, despite a reduced identification efficiency. Finally, we present an exploratory study of the measurement of Λc+ → p K-π+ in pp collisions at √{s}=7 TeV, using the Bayesian approach for the identification of its decay products.

  20. High mass resolution isochronous time-of-flight spectrograph for three-dimensional space plasma measurements

    NASA Technical Reports Server (NTRS)

    Moebius, E.; Bochsler, P.; Ghielmetti, A. G.; Hamilton, D. C.

    1990-01-01

    By combining a toroidal electrostatic analyzer with a novel cylindrically symmetric isochronous time-of-flight mass spectrometer, an instrument was developed that simultaneously determines the three-dimensional distribution function of ions and differentiates species. The ion mass is determined to high resolution (M/Delta-M greater than 50) from the time of flight within a harmonic field configuration defined by hyperboloid equipotential surfaces. A second conventional time-of-flight channel makes use of particles leaving the thin entrance foil as neutrals. An additional solid state detector in which the neutrals are stopped allows the total energy and thereby the ionic charge of the incident ions to be determined as well. Information from the neutral and the ion channels can be combined to determine the total mass of an incident molecular ion and the mass of one atomic fragment.

  1. A 3D profile function suitable for integration of neutron time-of-flight single crystal diffraction peaks

    NASA Astrophysics Data System (ADS)

    Gutmann, Matthias J.

    2017-03-01

    A 3D profile function is presented suitable to integrate reflections arising in time-of-flight (TOF) single crystal neutron diffraction experiments. In order to account for the large asymmetry of the peak shape in the TOF direction, a 3D Gaussian ellipsoid in the pixel (x, z) and time-of-flight coordinates is convoluted with a rising and falling exponential along the time-of-flight direction. An analytic expression is derived, making it suitable for least-squares fitting. The application of this function in detector space or reciprocal space is straightforward.

  2. Studies of Electronic Stopping Powers Using Time of Flight Spectrometry

    SciTech Connect

    Zhang, Yanwen; Weber, William J.

    2004-06-01

    Determination of electronic stopping powers using Time of Flight (ToF) spectrometry have been demonstrated by measuring energy loss of He, O, and Al particles based on a ToF Elastic Recoil Detection Analysis (ERDA) set-up. In transmission geometry, the energy loss of the particles in self-supported stopping foils of C, Si and SiC is measured over a continuous range of energies using the ToF spectrometer. This study emphasizes the difference of the stopping power determination with and without dependence on the Si detector calibration over a wide energy range. By calibrating the Si detector for each channel over the measured energy region, the improved approach eliminates much of the error associated with pulsed height defects and measurement uncertainties of less than 4% are achieved. Stopping powers from this study are compared with limited experimental data from the literature and SRIM (The Stopping and Range of Ions in Matter) 2000 and 2003 predictions. In general, the predicted values are in reasonable agreement with the experimental data, and an improved accuracy of SRIM 2003 over SRIM 2000 can be observed in some cases. Furthermore, Braggs rule is valid in SiC for O and Al over the energy region studied.

  3. Electronics for a Picosecond Time-of-flight Measurement

    SciTech Connect

    Brandt, Andrew Gerhart; Rijssenbeek, Michael

    2014-11-03

    TITLE: Electronics for a Picosecond Time-of-flight Measurement ABSTRACT: Time-of-flight (TOF) detectors have historically been used as part of the particle identification capability of multi-purpose particle physics detectors. An accurate time measurement, combined with a momentum measurement based on the curvature of the track in a magnetic field, is often sufficient to determine the particle's mass, and thus its identity. Such detectors typically have measured the particle flight time extremely precisely, with an uncertainty of one hundred trillionths of a second (also referred to as 100 picoseconds). To put this in perspective it would be like counting all the people on the Earth and getting it right within 1 person! Another use of TOFs is to measure the vertex of the event, which is the location along the beam line where the incoming particles (typically protons) collide. This vertex positon is a well measured quantity for events where the protons collide “head on” as the outgoing particles produced when you blast the proton apart can be used to trace back to a vertex point from which they originated. More frequently the protons just strike a glancing blow and remain intact—in this case they are nearly parallel to the beam and you cannot tell their vertex without this ability to precisely measure the time of flight of the protons. Occasionally both happen in the same event, that is, a central system and two protons are produced. But are they from the same collision, or just a boring background where more than one collision in the same bunch crossing conspire to fake the signal of interest? That’s where the timing of the protons comes into play. The main idea is to measure the time it takes for the two protons to reach TOF detectors positioned equidistant from the center of the main detector. If the vertex is displaced to one side than that detector will measure a shorter time while the other side detector will measure a correspondingly longer time

  4. Performance of the Tachyon Time-of-Flight PET Camera.

    PubMed

    Peng, Q; Choong, W-S; Vu, C; Huber, J S; Janecek, M; Wilson, D; Huesman, R H; Qi, Jinyi; Zhou, Jian; Moses, W W

    2015-02-01

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 × 25 mm(2) side of 6.15 × 6.15 × 25 mm(3) LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. The results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.

  5. Performance of the Tachyon Time-of-Flight PET Camera

    PubMed Central

    Peng, Q.; Choong, W.-S.; Vu, C.; Huber, J. S.; Janecek, M.; Wilson, D.; Huesman, R. H.; Qi, Jinyi; Zhou, Jian; Moses, W. W.

    2015-01-01

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon’s detector module is optimized for timing by coupling the 6.15 × 25 mm2 side of 6.15 × 6.15 × 25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/− ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. The results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3. PMID:26594057

  6. Performance of the Tachyon Time-of-Flight PET Camera

    DOE PAGES

    Peng, Q.; Choong, W. -S.; Vu, C.; ...

    2015-01-23

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 ×25 mm2 side of 6.15 ×6.15 ×25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMAmore » NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- 20 ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. We find that the results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.« less

  7. Performance of the Tachyon Time-of-Flight PET Camera

    SciTech Connect

    Peng, Q.; Choong, W. -S.; Vu, C.; Huber, J. S.; Janecek, M.; Wilson, D.; Huesman, R. H.; Qi, Jinyi; Zhou, Jian; Moses, W. W.

    2015-01-23

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 ×25 mm2 side of 6.15 ×6.15 ×25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- 20 ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. We find that the results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.

  8. The ALICE-HMPID Detector Control System: Its evolution towards an expert and adaptive system

    NASA Astrophysics Data System (ADS)

    De Cataldo, G.; Franco, A.; Pastore, C.; Sgura, I.; Volpe, G.

    2011-05-01

    The High Momentum Particle IDentification (HMPID) detector is a proximity focusing Ring Imaging Cherenkov (RICH) for charged hadron identification. The HMPID is based on liquid C 6F 14 as the radiator medium and on a 10 m 2 CsI coated, pad segmented photocathode of MWPCs for UV Cherenkov photon detection. To ensure full remote control, the HMPID is equipped with a detector control system (DCS) responding to industrial standards for robustness and reliability. It has been implemented using PVSS as Slow Control And Data Acquisition (SCADA) environment, Programmable Logic Controller as control devices and Finite State Machines for modular and automatic command execution. In the perspective of reducing human presence at the experiment site, this paper focuses on DCS evolution towards an expert and adaptive control system, providing, respectively, automatic error recovery and stable detector performance. HAL9000, the first prototype of the HMPID expert system, is then presented. Finally an analysis of the possible application of the adaptive features is provided.

  9. Digitizing data acquisition and time-of-flight pulse processing for ToF-ERDA

    NASA Astrophysics Data System (ADS)

    Julin, Jaakko; Sajavaara, Timo

    2016-01-01

    A versatile system to capture and analyze signals from multi channel plate (MCP) based time-of-flight detectors and ionization based energy detectors such as silicon diodes and gas ionization chambers (GIC) is introduced. The system is based on commercial digitizers and custom software. It forms a part of a ToF-ERDA spectrometer, which has to be able to detect recoil atoms of many different species and energies. Compared to the currently used analogue electronics the digitizing system provides comparable time-of-flight resolution and improved hydrogen detection efficiency, while allowing the operation of the spectrometer be studied and optimized after the measurement. The hardware, data acquisition software and digital pulse processing algorithms to suit this application are described in detail.

  10. Parameters’ Covariance in Neutron Time of Flight Analysis – Explicit Formulae

    SciTech Connect

    Odyniec, M.; Blair, J.

    2014-12-01

    We present here a method that estimates the parameters’ variance in a parametric model for neutron time of flight (NToF). The analytical formulae for parameter variances, obtained independently of calculation of parameter values from measured data, express the variances in terms of the choice, settings, and placement of the detector and the oscilloscope. Consequently, the method can serve as a tool in planning a measurement setup.

  11. Neutron xyz - polarization analysis at a time-of-flight instrument

    SciTech Connect

    Ehlers, Georg; Stewart, John Ross; Andersen, Ken

    2015-01-01

    When implementing a dedicated polarization analysis setup at a neutron time-of-flight instrument with a large area detector, one faces enormous challenges. Nevertheless, significant progress has been made towards this goal over the last few years. This paper addresses systematic limitations of the traditional method that is used to make these measurements, and a possible strategy to overcome these limitations. This will be important, for diffraction as well as inelastic experiments, where the scattering occurs mostly out-of-plane.

  12. A New Neutron Time-of-Flight Array for β-Decay Studies

    NASA Astrophysics Data System (ADS)

    Sénoville, M.; Delaunay, F.; Achouri, N. L.; Pârlog, M.; Orr, N. A.; Cano-Ott, D.; Carniol, B.; Étasse, D.; Fontbonne, C.; Fontbonne, J. M.; Gibelin, J.; Hommet, J.; Laurent, B.; Ledoux, X.; Marqués, F. M.; Martínez, T.; De Séréville, N.

    A new time-of-flight array for β-delayed neutron spectroscopy (En < 5 MeV) is being developed with the aim of improved performance compared to existing arrays. We report on the status of this development, in particular the study of the n-γ discrimination quality with digital electronics, a comparison of several organic scintillators, including new discriminating plastics, as well as the characterisation of detectors with monoenergetic neutrons to measure intrinsic efficiencies and cross-talk probabilities.

  13. A composition analyzer for microparticles using a spark ion source. [using time of flight spectrometers

    NASA Technical Reports Server (NTRS)

    Auer, S. O.; Berg, O. E.

    1975-01-01

    Iron microparticles were fired onto a capacitor-type microparticle detector which responded to an impact with a spark discharge. Ion currents were extracted from the spark and analyzed in a time-of-flight mass spectrometer. The mass spectra showed the element of both detector and particle materials. The total extracted ion currents was typically 10A within a period of 100ns, indicating very efficient vaporization of the particle and ionization of the vapor. Potential applications include research on cosmic dust, atmospheric aerosols and cloud droplets, particles ejected by rocket or jet engines, by machining processes, or by nuclear bomb explosions.

  14. Identification of micro-organisms using superconducting tunnel junctions and time-of-flight mass spectrometry

    SciTech Connect

    Benner, W H; Frank, M; Horn, J M; Labov, S E; Langry, K; Ullom, J

    1999-08-30

    We present time-of-flight measurements of biological material ejected from complete bacterial spores following laser irradiation. Ion impacts are registered on a microchannel plate and on a Superconducting Tunnel Junction (STJ) detector. We compare mass spectra obtained with the two detectors. The STJ has better sensitivity to massive ions and also measures the energy of each ion. We show evidence that spores of different bacillus species produce distinctive mass spectra and associate the observed mass peaks with coat proteins identified through ion-exchange extraction and gel electrophoresis.

  15. Time-of-flight x-ray photoconductivity of HgI/sub 2/

    SciTech Connect

    Kurtz, S.R.; Hughes, R.C.; Ortale, C.; Schnepple, W.F.

    1987-11-15

    Time-of-flight photoconductivity measurements were performed on HgI/sub 2/ using a penetrating, pulsed x-ray source, simulating the operation of photoconductive x-ray detectors. By examining a variety of HgI/sub 2/ samples, a wide range of electron and hole mobilities were observed, but in all cases hole transport was highly localized, limiting the collection of the photocarriers in HgI/sub 2/ detectors. The intrinsic photocarrier generation and recombination processes differed from classical Onsager and Langevin mechanisms observed in low-mobility photoconductors.

  16. Time of flight in MUSE at PIM1 at Paul Scherrer Institute

    NASA Astrophysics Data System (ADS)

    Lin, Wan; Gilman, Ronald; MUSE Collaboration

    2016-09-01

    The MUSE experiment at PIM1 at Paul Scherrer Institute in Villigen, Switzerland, measures elastic scattering of electrons and muons from a liquid hydrogen target. The intent of the experiment is to deduce whether the radius of the proton is the same when determined from the two different particle types. Precision timing is an important aspect of the experiment, used to determine particle types, reaction types, and beam momentum. Here we present results for a test setup measuring time of flight between prototypes of two detector systems to be used in the experiment, compared to Geant4 simulations. The results demonstrate time of flight resolution better than 100 ps, and beam momentum determination at the level of a few tenths of a percent. Douglass Project for Rutgers Women in Math, Science & Engineering, National Science Foundation Grant 1306126 to Rutgers University.

  17. Recent developments in time-of-flight PET.

    PubMed

    Vandenberghe, S; Mikhaylova, E; D'Hoe, E; Mollet, P; Karp, J S

    2016-12-01

    While the first time-of-flight (TOF)-positron emission tomography (PET) systems were already built in the early 1980s, limited clinical studies were acquired on these scanners. PET was still a research tool, and the available TOF-PET systems were experimental. Due to a combination of low stopping power and limited spatial resolution (caused by limited light output of the scintillators), these systems could not compete with bismuth germanate (BGO)-based PET scanners. Developments on TOF system were limited for about a decade but started again around 2000. The combination of fast photomultipliers, scintillators with high density, modern electronics, and faster computing power for image reconstruction have made it possible to introduce this principle in clinical TOF-PET systems. This paper reviews recent developments in system design, image reconstruction, corrections, and the potential in new applications for TOF-PET. After explaining the basic principles of time-of-flight, the difficulties in detector technology and electronics to obtain a good and stable timing resolution are shortly explained. The available clinical systems and prototypes under development are described in detail. The development of this type of PET scanner also requires modified image reconstruction with accurate modeling and correction methods. The additional dimension introduced by the time difference motivates a shift from sinogram- to listmode-based reconstruction. This reconstruction is however rather slow and therefore rebinning techniques specific for TOF data have been proposed. The main motivation for TOF-PET remains the large potential for image quality improvement and more accurate quantification for a given number of counts. The gain is related to the ratio of object size and spatial extent of the TOF kernel and is therefore particularly relevant for heavy patients, where image quality degrades significantly due to increased attenuation (low counts) and high scatter fractions. The

  18. Analytical properties of time-of-flight PET data.

    PubMed

    Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M

    2008-06-07

    We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the 'bow-tie' property of the 2D Radon transform to the time-of-flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data.

  19. Analytical Properties of Time-of-Flight PET Data

    PubMed Central

    Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M.

    2015-01-01

    We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the “bow-tie” property of the 2D Radon transform to the time of flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data. PMID:18460746

  20. Analytical properties of time-of-flight PET data

    NASA Astrophysics Data System (ADS)

    Cho, Sanghee; Ahn, Sangtae; Li, Quanzheng; Leahy, Richard M.

    2008-06-01

    We investigate the analytical properties of time-of-flight (TOF) positron emission tomography (PET) sinograms, where the data are modeled as line integrals weighted by a spatially invariant TOF kernel. First, we investigate the Fourier transform properties of 2D TOF data and extend the 'bow-tie' property of the 2D Radon transform to the time-of-flight case. Second, we describe a new exact Fourier rebinning method, TOF-FOREX, based on the Fourier transform in the time-of-flight variable. We then combine TOF-FOREX rebinning with a direct extension of the projection slice theorem to TOF data, to perform fast 3D TOF PET image reconstruction. Finally, we illustrate these properties using simulated data.

  1. Particle identification using time-of-flight technology for the ALICE experiment

    SciTech Connect

    Schmidt, H.R.

    1995-07-15

    The large multiplicities expected for LHC Pb+Pb collisions require new development in particle identification techniques. Presently, Pestov Spark Counters, low pressure Parallel Plate Chambers and scintillators with photo multiplier readout are under consideration.

  2. Time-of-Flight Mass Measurements of Neutron Rich Nuclides

    NASA Astrophysics Data System (ADS)

    Estrade, A.; Matos, M.; Amthor, A. M.; Becerril, A.; Elliot, T.; Lorusso, G.; Rogers, A.; Schatz, H.; Bazin, D.; Gade, A.; Portillo, M.; Stolz, A.; Galaviz, D.; Pereira, J.; Shapira, D.; Smith, E.; Wallace, M.

    2008-10-01

    Nuclear masses of neutron rich isotopes in the region of Z ˜ 20-30 have been measured using the time-of-flight technique at the National Superconducting Cyclotron Laboratory (NSCL). The masses of 5 isotopes have been measured for the first time, and the precision of several other masses has been improved. The time-of-flight technique has shown the potential to access nuclear masses very far from stability when applied at radioactive beam facilities like the NSCL. Such measurements are important for understanding nuclear structure far from the valley of β-stability, and provide valuable information for astrophysical model calculations of processes involving very unstable nuclides.

  3. ALICE Collaboration

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Böhmer, F. V.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Delagrange, H.; Deloff, A.; Dénes, E.; D'Erasmo, G.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; de Rooij, R.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Di Bari, D.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dørheim, S.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Hilden, T. E.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Esposito, M.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gumbo, M.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hippolyte, B.; Hladky, J.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Innocenti, G. M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Jachołkowski, A.; Jacobs, P. M.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Jusko, A.; Kadyshevskiy, V.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil SVN, M.; Khan, M. M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, S. H.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; Ladron de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; La Pointe, S. L.; La Rocca, P.; Lea, R.; Leardini, L.; Lee, G. R.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; Leoncino, M.; León Monzón, I.; Lévai, P.; Li, S.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Lohner, D.; Loizides, C.; Lopez, X.; López Torres, E.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luparello, G.; Ma, R.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martin Blanco, J.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mlynarz, J.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Morando, M.; Moreira De Godoy, D. A.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Müller, H.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Nattrass, C.; Nayak, K.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Sahoo, P.; Pachmayer, Y.; Pachr, M.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S. K.; Palmeri, A.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Patalakha, D. I.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Pesci, A.; Peskov, V.; Pestov, Y.; Petráček, V.; Petran, M.; Petris, M.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Pohjoisaho, E. H. O.; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Rauf, A. W.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohni, S.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, R.; Sahu, P. K.; Saini, J.; Sakai, S.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Sánchez Rodríguez, F. J.; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Segato, G.; Seger, J. E.; Sekiguchi, Y.; Selyuzhenkov, I.; Senosi, K.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, N.; Sharma, S.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Spacek, M.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Susa, T.; Symons, T. J. M.; Szabo, A.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tarazona Martinez, A.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Vande Vyvre, P.; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, M.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wagner, V.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Weber, S. G.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yang, S.; Yano, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I.-K.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zach, C.; Zaman, A.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, F.; Zhou, Y.; Zhou, Zhuo; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zoccarato, Y.; Zyzak, M.

    2014-11-01

    The ALICE Collaboration would like to thank all its engineers and technicians for their invaluable contributions to the construction of the experiment and the CERN accelerator teams for the outstanding performance of the LHC complex.

  4. MAD - Monitoring ALICE Dataflow

    NASA Astrophysics Data System (ADS)

    Chibante Barroso, V.; Costa, F.; Grigoras, C.; Wegrzynek, A.

    2015-12-01

    ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Following a successful Run 1, which ended in February 2013, the ALICE data acquisition (DAQ) entered a consolidation phase to prepare for Run 2 which will start in the beginning of 2015. A new software tool has been developed by the data acquisition project to improve the monitoring of the experiment's dataflow, from the data readout in the DAQ farm up to its shipment to CERN's main computer centre. This software, called ALICE MAD (Monitoring ALICE Dataflow), uses the MonALISA framework as core module to gather, process, aggregate and distribute monitoring values from the different processes running in the distributed DAQ farm. Data are not only pulled from the data sources to MAD but can also be pushed by dedicated data collectors or the data source processes. A large set of monitored metrics (from the backpressure status on the readout links to event counters in each of the DAQ nodes and aggregated data rates for the whole data acquisition) is needed to provide a comprehensive view of the DAQ status. MAD also injects alarms in the Orthos alarm system whenever abnormal conditions are detected. The MAD web-based GUI uses WebSockets to provide dynamic and on-time status displays for the ALICE shift crew. Designed as a widget-based system, MAD supports an easy integration of new visualization blocks and also customization of the information displayed to the shift crew based on the ALICE activities.

  5. National Ignition Facility (NIF) Neutron time-of-flight (nTOF) Measurements

    SciTech Connect

    Lerche, R A; Glebov, V Y; Moran, M J; McNaney, J M; Kilkenny, J D; Eckart, M; Zacharias, R A; Haslam, J J; Clancy, T J; Yeoman, M F; Warwas, D P; Sangster, T C; Stoeckl, C; Knauer, J; Horsfield, C J

    2010-05-13

    The first three of eighteen neutron time-of-flight (nTOF) channels have been installed at the National Ignition Facility (NIF). The role of these detectors includes yield, temperature, and bang time measurements. This article focuses on nTOF data analysis and quality of results obtained for the first set of experiments to use all 192 NIF beams. Targets produced up to 2 x 10{sup 10} 2.45-MeV neutrons for initial testing of the nTOF detectors. Differences in neutron scattering at the OMEGA laser facility where the detectors were calibrated and at NIF result in different response functions at the two facilities. Monte Carlo modeling shows this difference. The nTOF performance on these early experiments indicates the nTOF system with its full complement of detectors should perform well in future measurements of yield, temperature, and bang time.

  6. Time-of-flight technique for particle identification at energies from 2 to 400 keV/nucleon

    NASA Technical Reports Server (NTRS)

    Gloeckler, G.; Hsieh, K. C.

    1979-01-01

    The time of flight technique for particle identification was extended to 2 keV/nucleon and the size of the start-time detector was reduced considerably by the use of carbon foils of few micrograms/cm square in thickness combined with microchannel plates for detecting secondary electrons. Time of flight telescopes incorporating this start-time device were used to measure the stopping power of a number of low energy heavy ions in thin carbon foils and the charge states of these ions emerging from such foils. Applications for the detection and identification of low energy interplanetary and magnetospheric particles are suggested.

  7. Highly segmented, high resolution time-of-flight system

    SciTech Connect

    Nayak, T.K.; Nagamiya, S.; Vossnack, O.; Wu, Y.D.; Zajc, W.A.; Miake, Y.; Ueno, S.; Kitayama, H.; Nagasaka, Y.; Tomizawa, K.; Arai, I.; Yagi, K

    1991-12-31

    The light attenuation and timing characteristics of time-of-flight counters constructed of 3m long scintillating fiber bundles of different shapes and sizes are presented. Fiber bundles made of 5mm diameter fibers showed good timing characteristics and less light attenuation. The results for a 1.5m long scintillator rod are also presented.

  8. Rocket-borne time-of-flight mass spectrometry

    NASA Technical Reports Server (NTRS)

    Reiter, R. F.

    1976-01-01

    Theoretical and numerical analyses are made of planar, cylindrical and spherical-electrode two-field time-of-flight mass spectrometers in order to optimize their operating conditions. A method is introduced which can improve the resolving power of these instruments by a factor of 7.5. Potential barrier gating in time-of-flight mass spectrometers is also analyzed. Experimental studies of a miniature cylindrical-electrode and a hemispherical-electrode time-of-flight mass spectrometer are presented. Their sensitivity and ability to operate at D-region pressures with an open source make them ideal instruments for D-region ion composition measurements. A sounding rocket experiment package carrying a cylindrical electrode time-of-flight mass spectrometer was launched. The data indicate that essentially 100% of the positive electric charge on positive ions is carried by ions with mass-to-charge ratios greater than 500 below an altitude of 92 km. These heavy charge carriers were present at altitudes up to about 100 km.

  9. 14 CFR 398.7 - Timing of flights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Timing of flights. 398.7 Section 398.7 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) POLICY... reasonableness of the time in view of the purpose for which the local passengers are traveling. If travel...

  10. Application of the Monte Carlo methods and variational procedure for optimizing time-of-flight neutron diffractometer characteristics

    NASA Astrophysics Data System (ADS)

    Khrushchinsky, A. A.; Kuten, S. A.; Viarenich, K. A.; Speransky, P. A.

    2016-05-01

    Based on variational calculus, a procedure for the optimal approximation of detector surface of the time-of-flight neutron diffractometer has been suggested. The exact solution for a point sample and zero thickness detector has been obtained. Using the shape of the detector surface, an optimized Monte Carlo simulation has been performed for the parameters of the spectrometer depending on the sample size and detector thickness, its azimuthal and Bragg's angular dimensions, and taking into account the neutron absorption in the sample and detector.

  11. Picosecond resolution on relativistic heavy ions' time-of-flight measurement

    NASA Astrophysics Data System (ADS)

    Ebran, A.; Taieb, J.; Belier, G.; Chatillon, A.; Laurent, B.; Martin, J.-F.; Pellereau, E.

    2013-11-01

    We developed a time-of-flight measurement system for relativistic heavy ions with a requested resolution of 40 ps Full Width Half Maximum. Such a resolution is mandatory to assign the correct mass number to every fission fragment, identified using the Bρ-ToF-ΔE method with the recoil spectrometer designed for the SOFIA experiment-which hold very recently at GSI. To achieve such a performance, fast plastic scintillators read-out by dedicated photomultiplier tubes were chosen among other possible options. We have led several test-measurements from 2009 to 2011, in order to investigate: the effect of the addition of a quenching molecule in the scintillator's matrix, the influence of the detector's size and the impact of the photomultiplier tube. The contribution of the dedicated electronics is also characterized. Time-of-flight measurements were performed realized with electron pulses and relativistic heavy ions, respectively provided by the LASER driven electron-accelerator (ELSA) at CEA-DAM Ile-de-France and by the SIS18/FRS facility at GSI. The reported results exhibit a time resolution better than 20 ps Full Width Half Maximum reached with the last prototype at GSI with an Uranium beam. These results confirm that the SOFIA experiment should enable the measurement of the relativistic fission fragments' time-of-flight with the requested resolution.

  12. Pattern recognition and PID procedure with the ALICE-HMPID

    NASA Astrophysics Data System (ADS)

    Volpe, Giacomo

    2014-12-01

    The ALICE apparatus is dedicated to the study of pp, p-Pb and Pb-Pb collisions provided by LHC. ALICE has unique particle identification (PID) capabilities among the LHC experiments exploiting different PID techniques, i.e., energy loss, time-of-flight measurements, Cherenkov and transition radiation detection, calorimetry and topological ID. The ALICE-HMPID is devoted to the identification of charged hadrons. It consists of seven identical RICH counters, with liquid C6F14 as Cherenkov radiator (n≈1.299 at λph=175 nm). Photons and charged particles detection is performed by a proportional chamber, coupled with a pad segmented CsI coated photo-cathode. In pp and p-Pb events HMPID provides 3 sigmas separation for pions and kaons up to pT = 3 GeV / c and for protons up to pT = 5 GeV / c. PID is performed by means of photon emission angle measurement, a challenging task in the high multiplicity environment of the most central Pb-Pb collisions. A dedicated algorithm has been implemented to evaluate the Cherenkov angle starting from the bi-dimensional ring pattern on the photons detector, it is based on the Hough Transform Method (HTM) to separate signal from background. In this way HMPID is able to contribute to inclusive hadrons spectra measurement as well as to measurements where high purity PID is required, by means of statistical or track-by-track PID. The pattern recognition, the results from angular resolution studies and the PID strategy with HMPID are presented.

  13. Central Diffraction in ALICE

    SciTech Connect

    Schicker, R.

    2011-07-15

    The ALICE experiment consists of a central barrel in the pseudorapidity range -0.9<{eta}<0.9 and of additional detectors covering about 3 units of pseudorapidity on either side of the central barrel. Such a geometry allows the tagging of single and double gap events. The status of the analysis of such diffractive events in proton-proton collisions at {radical}(s) = 7 TeV is presented.

  14. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    The ALICE Collaboration

    2016-01-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. In this paper, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. This analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density ρμ > 5.9 m-2. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above 1016 eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. The development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.

  15. A compact time-of-flight spectrometer for electrofission studies*

    NASA Astrophysics Data System (ADS)

    Heil, R. D.; Drexler, J.; Huber, K.; Kneissl, U.; Mank, G.; Ries, H.; Ströher, H.; Weber, T.; Wilke, W.

    1985-09-01

    A compact time-of-flight spectrometer for measurements of fission fragment distributions is described. The start detector consists of a channel plate arrangement with an electrostatic mirror. The time resolution of PPACs, serving as stop detectors, has been optimized. Velocity distributions of 252Cf fragments and mean velocities are reported. The results are discussed with respect to planned (e, e'f) coincidence experiments at the Mainz microtron.

  16. Studies for dimuon measurement with ALICE

    SciTech Connect

    Jouan, D.

    1995-07-15

    The idea of measuring dimuon in the ALICE detector is not new, since it already appeared in the Aachen Conference. In the meantime studies were aiming at the use of the two detectors of LHC p-p physics, CMS and ATLAS, already dedicated to dimuon measurement, for these same measurements in heavy ion collisions, whereas the detector dedicated to heavy ions physics at LHC, ALICE, was considering all the other observables. Recently, the interest for dimuon measurements in ALICE was renewed by demands from LHC committee, stiring the activities of a working group in the ALICE collaboration, also associated to a more recent move from new groups. In the following the author briefly describes the interest of measuring dimuons in heavy ion collisions, particularly in ALICE, then the experimental strategy and first estimates of the performances that could be reached with the proposed system.

  17. Integration of neutron time-of-flight single-crystal Bragg peaks in reciprocal space

    SciTech Connect

    Schultz, Arthur J; Joergensen, Mads; Wang, Xiaoping; Mikkelson, Ruth L; Mikkelson, Dennis J; Lynch, Vickie E; Peterson, Peter F; Green, Mark L; Hoffmann, Christina

    2014-01-01

    The intensity of single crystal Bragg peaks obtained by mapping neutron time-of-flight event data into reciprocal space and integrating in various ways are compared. These include spherical integration with a fixed radius, ellipsoid fitting and integrating of the peak intensity and one-dimensional peak profile fitting. In comparison to intensities obtained by integrating in real detector histogram space, the data integrated in reciprocal space results in better agreement factors and more accurate atomic parameters. Furthermore, structure refinement using integrated intensities from one-dimensional profile fitting is demonstrated to be more accurate than simple peak-minus-background integration.

  18. Biomark/Organic Analysis with Time-of-Flight Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Waite, J. Hunter, Jr.

    2004-01-01

    The concept of a Comprehensive 2-Dimensional Gas Chromatography coupled with Time-of-Flight Mass Spectrometry (GCxGC-TOWS) for the analysis of organic compounds has been proven with commercially available instrumentation (LECO Corp). The performance of a GCxGC instrument has been characterized in various stages using two independent breadboard systems. The GCxGC separation systems, including the thermal modulator, have been miniaturized to the size of a benchtop configuration. One breadboard system employs a Flame Ionization Detector (FID), whereas the second breadboard system employs a Time-of-Fight mass spectrometer (TOFWS) as a detection system.

  19. Lanthanum halide scintillators for time-of-flight 3-D pet

    DOEpatents

    Karp, Joel S.; Surti, Suleman

    2008-06-03

    A Lanthanum Halide scintillator (for example LaCl.sub.3 and LaBr.sub.3) with fast decay time and good timing resolution, as well as high light output and good energy resolution, is used in the design of a PET scanner. The PET scanner includes a cavity for accepting a patient and a plurality of PET detector modules arranged in an approximately cylindrical configuration about the cavity. Each PET detector includes a Lanthanum Halide scintillator having a plurality of Lanthanum Halide crystals, a light guide, and a plurality of photomultiplier tubes arranged respectively peripherally around the cavity. The good timing resolution enables a time-of-flight (TOF) PET scanner to be developed that exhibits a reduction in noise propagation during image reconstruction and a gain in the signal-to-noise ratio. Such a PET scanner includes a time stamp circuit that records the time of receipt of gamma rays by respective PET detectors and provides timing data outputs that are provided to a processor that, in turn, calculates time-of-flight (TOF) of gamma rays through a patient in the cavity and uses the TOF of gamma rays in the reconstruction of images of the patient.

  20. KELVIN rare gas time-of-flight program

    SciTech Connect

    Vernon, M.

    1981-03-01

    The purpose of this appendix is to explain in detail the procedure for performing time-of-flight (TOF) calibration measurements. The result of the calibration measurements is to assign a correct length (L) to the path the molecules travel in a particular experimental configuration. In conjunction with time information (t) a velocity distribution (L/t) can then be determined. The program KELVIN is listed.

  1. Time-of-flight direct recoil ion scattering spectrometer

    DOEpatents

    Krauss, Alan R.; Gruen, Dieter M.; Lamich, George J.

    1994-01-01

    A time of flight direct recoil and ion scattering spectrometer beam line (10). The beam line (10) includes an ion source (12) which injects ions into pulse deflection regions (14) and (16) separated by a drift space (18). A final optics stage includes an ion lens and deflection plate assembly (22). The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions (14) and (16).

  2. Time-of-flight direct recoil ion scattering spectrometer

    DOEpatents

    Krauss, A.R.; Gruen, D.M.; Lamich, G.J.

    1994-09-13

    A time-of-flight direct recoil and ion scattering spectrometer beam line is disclosed. The beam line includes an ion source which injects ions into pulse deflection regions and separated by a drift space. A final optics stage includes an ion lens and deflection plate assembly. The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions. 23 figs.

  3. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    SciTech Connect

    Collaboration: ALICE Collaboration

    2016-01-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. In this paper, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. This analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density ρ{sub μ} > 5.9 m{sup −2}. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above 10{sup 16} eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. The development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.

  4. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    SciTech Connect

    Adam, J.

    2016-01-19

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. Here, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. Our analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density rho(mu) > 5.9 m(-2). Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above 10(16) eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. Furthermore, the development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.

  5. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    DOE PAGES

    Adam, J.

    2016-01-19

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. Here, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. Our analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more thanmore » 100 reconstructed muons and corresponding to a muon areal density rho(mu) > 5.9 m(-2). Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above 10(16) eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. Furthermore, the development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.« less

  6. Geometry Survey of the Time-of-Flight Neutron-Elastic Scattering (Antonella) Experiment

    SciTech Connect

    Oshinowo, Babatunde O.; Izraelevitch, Federico

    2016-10-17

    The Antonella experiment is a measurement of the ionization efficiency of nuclear recoils in silicon at low energies [1]. It is a neutron elastic scattering experiment motivated by the search for dark matter particles. In this experiment, a proton beam hits a lithium target and neutrons are produced. The neutron shower passes through a collimator that produces a neutron beam. The beam illuminates a silicon detector. With a certain probability, a neutron interacts with a silicon nucleus of the detector producing elastic scattering. After the interaction, a fraction of the neutron energy is transferred to the silicon nucleus which acquires kinetic energy and recoils. This kinetic energy is then dissipated in the detector producing ionization and thermal energy. The ionization produced is measured with the silicon detector electronics. On the other hand, the neutron is scattered out of the beam. A neutron-detector array (made of scintillator bars) registers the neutron arrival time and the scattering angle to reconstruct the kinematics of the neutron-nucleus interaction with the time-of-flight technique [2]. In the reconstruction equations, the energy of the nuclear recoil is a function of the scattering angle with respect to the beam direction, the time-of-flight of the neutron and the geometric distances between components of the setup (neutron-production target, silicon detector, scintillator bars). This paper summarizes the survey of the different components of the experiment that made possible the off-line analysis of the collected data. Measurements were made with the API Radian Laser Tracker and I-360 Probe Wireless. The survey was completed at the University of Notre Dame, Indiana, USA in February 2015.

  7. Measurement of inclusive jet spectra in pp, p–Pb, and Pb–Pb collisions with the ALICE detector

    NASA Astrophysics Data System (ADS)

    Haake, Rüdiger; ALICE Collaboration

    2017-02-01

    Highly energetic jets are sensitive probes of the kinematic properties and the topology of high energy hadron collisions. Jets are collimated sprays of charged and neutral particles, which are produced in fragmentation of hard scattered partons from an early stage of the collision. In ALICE, jets have been measured in pp, p–Pb, and Pb–Pb collisions at several collision energies. While analyses of Pb–Pb events unveil properties of the hot and dense medium formed in heavy-ion collisions, pp and p–Pb collisions can shed light on hadronization and cold nuclear matter effects in jet production. Additionally, pp and p–Pb collisions serve as a baseline for disentangling hot and cold nuclear matter effects. A possible modification of the initial state is tested in p–Pb analyses. For the extraction of a jet signal, the exact evaluation of the background from the underlying event is an especially important ingredient. Due to the different nature of underlying events, each collision system requires a different analysis technique for removing the effect of the background on the jet sample. The focus of this publication is on the ALICE measurements of nuclear modification factors connecting p–Pb and Pb–Pb events to pp collisions. Furthermore, the radial jet structure is explored by comparing jet spectra reconstructed with different resolution parameters.

  8. Development of the FoCal-E PAD detector and its electronics for the ALICE experiment at the LHC

    NASA Astrophysics Data System (ADS)

    Inaba, Motoi; Chujo, Tatsuya; Hirano, Masahiro

    2016-07-01

    In order to study the initial state of high-energy heavy-ion collisions, a forward calorimeter as an upgrade to the ALICE experiment is in the planning stage. The first beam test of the forward electro-magnetic calorimeter (FoCal-E) prototype was carried out in 2014 at the CERN PS and SPS accelerators. With the aim of reading out a signal from the low-granularity silicon pad sensors of FoCal-E, electronic circuits such as a temperature monitor, a trigger-signal converting-circuit, a trigger-signal processor, an independent regulated power circuit and an isolated high-voltage generator were developed. The electric noise problem was solved by means of both the power circuit and the high-voltage generator, and the signal was successfully read out.

  9. Continuous time-of-flight ion mass spectrometer

    DOEpatents

    Funsten, Herbert O.; Feldman, William C.

    2004-10-19

    A continuous time-of-flight mass spectrometer having an evacuated enclosure with means for generating an electric field located in the evacuated enclosure and means for injecting a sample material into the electric field. A source of continuous ionizing radiation injects ionizing radiation into the electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between arrival of a secondary electron out of said ionized atoms or molecules at a first predetermined location and arrival of a sample ion out of said ionized atoms or molecules at a second predetermined location.

  10. Time-of-Flight Tip-Clearance Measurements

    NASA Technical Reports Server (NTRS)

    Dhadwal, H. S.; Kurkov, A. P.; Janetzke, D. C.

    1999-01-01

    In this paper a time-of-flight probe system incorporating the two integrated fiber optic probes which are tilted equally relative to the probe holder centerline, is applied for the first time to measure the tip clearance of an advanced fan prototype. Tip clearance is largely independent of the signal amplitude and it relies on timing measurement. This work exposes optical effects associated with the fan blade stagger angle that were absent during the original spin-rig experiment on the zero stagger rotor. Individual blade tip clearances were measured with accuracy of +/- 127-mm (+/- 0.005-in). Probe features are discussed and improvements to the design are suggested.

  11. An introduction to quadrupole-time-of-flight mass spectrometry.

    PubMed

    Chernushevich, I V; Loboda, A V; Thomson, B A

    2001-08-01

    A brief introduction is presented to the basic principles and application of a quadrupole-time-of-flight (TOF) tandem mass spectrometer. The main features of reflecting TOF instruments with orthogonal injection of ions are discussed. Their operation and performance are compared with those of triple quadrupoles with electrospray ionization and matrix-assisted laser desorption/ionization (MALDI) TOF mass spectrometers. Examples and recommendations are provided for all major operational modes: mass spectrometry (MS) and tandem MS (MS/MS), precursor ion scans and studies of non-covalent complexes. Basic algorithms for liquid chromatography/MS/MS automation are discussed and illustrated by two applications.

  12. Development of an ion time-of-flight spectrometer for neutron depth profiling

    NASA Astrophysics Data System (ADS)

    Cetiner, Mustafa Sacit

    Ion time-of-flight spectrometry techniques are investigated for applicability to neutron depth profiling. Time-of-flight techniques are used extensively in a wide range of scientific and technological applications including energy and mass spectroscopy. Neutron depth profiling is a near-surface analysis technique that gives concentration distribution versus depth for certain technologically important light elements. The technique uses thermal or sub-thermal neutrons to initiate (n, p) or (n, alpha) reactions. Concentration versus depth distribution is obtained by the transformation of the energy spectrum into depth distribution by using stopping force tables of the projectiles in the substrate, and by converting the number of counts into concentration using a standard sample of known dose value. Conventionally, neutron depth profiling measurements are based on charged particle spectrometry, which employs semiconductor detectors such as a surface barrier detector (SBD) and the associated electronics. Measurements with semiconductor detectors are affected by a number of broadening mechanisms, which result from the interactions between the projectile ion and the detector material as well as fluctuations in the signal generation process. These are inherent features of the detection mechanism that involve the semiconductor detectors and cannot be avoided. Ion time-of-flight spectrometry offers highly precise measurement capabilities, particularly for slow particles. For high-energy low-mass particles, measurement resolution tends to degrade with all other parameters fixed. The threshold for more precise ion energy measurements with respect to conventional techniques, such as direct energy measurement by a surface barrier detector, is directly related to the design and operating parameters of the device. Time-of-flight spectrometry involves correlated detection of two signals by a coincidence unit. In ion time-of-flight spectroscopy, the ion generates the primary input

  13. Quasi-dynamic mode of nanomembranes for time-of-flight mass spectrometry of proteins

    NASA Astrophysics Data System (ADS)

    Park, Jonghoo; Kim, Hyunseok; Blick, Robert H.

    2012-03-01

    Mechanical resonators realized on the nano-scale by now offer applications in mass-sensing of biomolecules with extraordinary sensitivity. The general idea is that perfect mechanical biosensors should be of extremely small size to achieve zeptogram sensitivity in weighing single molecules similar to a balance. However, the small scale and long response time of weighing biomolecules with a cantilever restrict their usefulness as a high-throughput method. Commercial mass spectrometry (MS) such as electro-spray ionization (ESI)-MS and matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF)-MS are the gold standards to which nanomechanical resonators have to live up to. These two methods rely on the ionization and acceleration of biomolecules and the following ion detection after a mass selection step, such as time-of-flight (TOF). Hence, the spectrum is typically represented in m/z, i.e. the mass to ionization charge ratio. Here, we describe the feasibility and mass range of detection of a new mechanical approach for ion detection in time-of-flight mass spectrometry, the principle of which is that the impinging ion packets excite mechanical oscillations in a silicon nitride nanomembrane. These mechanical oscillations are henceforth detected via field emission of electrons from the nanomembrane. Ion detection is demonstrated in MALDI-TOF analysis over a broad range with angiotensin, bovine serum albumin (BSA), and an equimolar protein mixture of insulin, BSA, and immunoglobulin G (IgG). We find an unprecedented mass range of operation of the nanomembrane detector.

  14. Time of flight Laue fiber diffraction studies of perdeuterated DNA

    SciTech Connect

    Forsyth, V.T.; Whalley, M.A.; Mahendrasingam, A.; Fuller, W.

    1994-12-31

    The diffractometer SXD at the Rutherford Appleton Laboratory ISIS pulsed neutron source has been used to record high resolution time-of-flight Laue fiber diffraction data from DNA. These experiments, which are the first of their kind, were undertaken using fibers of DNA in the A conformation and prepared using deuterated DNA in order to minimis incoherent background scattering. These studies complement previous experiments on instrument D19 at the Institute Laue Langevin using monochromatic neutrons. Sample preparation involved drawing large numbers of these deuterated DNA fibers and mounting them in a parallel array. The strategy of data collection is discussed in terms of camera design, sample environment and data collection. The methods used to correct the recorded time-of-flight data and map it into the final reciprocal space fiber diffraction dataset are also discussed. Difference Fourier maps showing the distribution of water around A-DNA calculated on the basis of these data are compared with results obtained using data recorded from hydrogenated A-DNA on D19. Since the methods used for sample preparation, data collection and data processing are fundamentally different for the monochromatic and Laue techniques, the results of these experiments also afford a valuable opportunity to independently test the data reduction and analysis techniques used in the two methods.

  15. Time-of-flight mass spectrometry: Introduction to the basics.

    PubMed

    Boesl, Ulrich

    2017-01-01

    The intention of this tutorial is to introduce into the basic concepts of time-of-flight mass spectrometry, beginning with the most simple single-stage ion source with linear field-free drift region and continuing with two-stage ion sources combined with field-free drift regions and ion reflectors-the so-called reflectrons. Basic formulas are presented and discussed with the focus on understanding the physical relations of geometric and electric parameters, initial distribution of ionic parameters, ion flight times, and ion flight time incertitude. This tutorial is aimed to help the applicant to identify sources of flight time broadening which limit good mass resolution and sources of ion losses which limit sensitivity; it is aimed to stimulate creativity for new experimental approaches by discussing a choice of instrumental options and to encourage those who toy with the idea to build an own time-of-flight mass spectrometer. Large parts of mathematics are shifted into a separate chapter in order not to overburden the text with too many mathematical deviations. Rather, thumb-rule formulas are supplied for first estimations of geometry and potentials when designing a home-built instrument, planning experiments, or searching for sources of flight time broadening. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 36:86-109, 2017.

  16. Inductively Coupled Plasma Zoom-Time-of-Flight Mass Spectrometry.

    PubMed

    Dennis, Elise A; Ray, Steven J; Enke, Christie G; Hieftje, Gary M

    2016-03-01

    A zoom-time-of-flight mass spectrometer has been coupled to an inductively coupled plasma (ICP) ionization source. Zoom-time-of-flight mass spectrometry (zoom-TOFMS) combines two complementary types of velocity-based mass separation. Specifically, zoom-TOFMS alternates between conventional, constant-energy acceleration (CEA) TOFMS and energy-focused, constant-momentum acceleration (CMA) (zoom) TOFMS. The CMA mode provides a mass-resolution enhancement of 1.5-1.7× over CEA-TOFMS in the current, 35-cm ICP-zoom-TOFMS instrument geometry. The maximum resolving power (full-width at half-maximum) for the ICP-zoom-TOFMS instrument is 1200 for CEA-TOFMS and 1900 for CMA-TOFMS. The CMA mode yields detection limits of between 0.02 and 0.8 ppt, depending upon the repetition rate and integration time-compared with single ppt detection limits for CEA-TOFMS. Isotope-ratio precision is shot-noise limited at approximately 0.2% relative-standard deviation (RSD) for both CEA- and CMA-TOFMS at a 10 kHz repetition rate and an integration time of 3-5 min. When the repetition rate is increased to 43.5 kHz for CMA, the shot-noise limited, zoom-mode isotope-ratio precision is improved to 0.09% RSD for the same integration time.

  17. TITAN's multiple-reflection time-of-flight isobar separator

    NASA Astrophysics Data System (ADS)

    Reiter, Moritz Pascal; Titan Collaboration

    2016-09-01

    At the ISAC facility located at TRIUMF exotic nuclei are produced by the ISOL method. Exotic nuclei are separated by a magnetic separator and transported to TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). TITAN is a system of multiple ion traps for high precision mass measurements and in-trap decay spectroscopy. Although ISAC can deliver some of the highest yields for even many of the most exotic species many measurements suffer from a strong isobaric background. This background often prevents the high precision measurement of the species of interest. To overcome this limitation an additional isobar separator based on the Multiple-Reflection Time-Of-Flight Mass Spectrometry (MR-TOF-MS) technique has been developed for TITAN. Mass selection is achieved using dynamic re-trapping of the species of interest after a time-of-flight analysis in an electrostatic isochronous reflector system. Additionally the MR-TOF-MS will, on its own, enable mass measurements of very short-lived nuclides that are weakly produced. Being able to measure all isobars of a given mass number at the same time the MR-TOF-MS can be used for beam diagnostics or determination of beam compositions. Results from the offline commissioning showing mass resolving power and separation power will be presented.

  18. Determination of Imazaquin and its metabolite by liquid chromatography-quadrupole-time of flight tandem mass.

    PubMed

    Yao, H B; Han, G J; Liu, G X; Xie, Y; Wang, C H

    2010-08-01

    A method consisting of solvent extraction followed by liquid chromatography-quadrupole-time of flight- tandem mass spectrometry analysis was developed for the identification of Imazaquin and its metabolite. The relationships between detector response and sample concentrations showed a high degree of linearity (r > 0.998) over the range 0.03-10 microg/g. The recoveries obtained were in the acceptable range of 86%-104% between spiked. The relative standard deviation of this method was 6.4%-17.1%. A 35-day study of Imazaquin degradation was taken in agricultural soil from Binzhou, China. The degradation followed first order kinetics (C = 0.7672e(-0.0774t)), with half-life of less than 8.5 days. Investigation of the by-products from liquid chromatography-quadrupole-time of flight- tandem mass spectrometry has shown that there were four important metabolites 4-methylene-2-(quinolin-2-yl)-1H-imidazol-5(4H)-one, quinoline-3-carbaldehyde, 1-amino-2,3-dimethyl-1-oxobutan-2-ylium and 1H-[1,2]oxazino[4,5-b]quinolin-1-one in the degradation process. The accurate mass measurements error was 5 ppm in this study. The method was successfully applied to the analysis of imazaquin and its metabolite residues in soil.

  19. Fast neutron measurements at the nELBE time-of-flight facility

    NASA Astrophysics Data System (ADS)

    Junghansa, A. R.; Beyer, R.; Grosse, E.; Hannaske, R.; Kögler, T.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2015-05-01

    The compact neutron-time-of-flight facility nELBE at the superconducting electron accelerator ELBE of Helmholtz-Zentrum Dresden-Rossendorf has been rebuilt. A new enlarged experimental hall with a flight path of up to 10 m is available for neutron time-of-flight experiments in the fast energy range from about 50 keV to 10 MeV. nELBE is intended to deliver nuclear data of fast neutron nuclear interactions e.g. for the transmutation of nuclear waste and improvement of neutron physical simulations of innovative nuclear systems. The experimental programme consists of transmission measurements of neutron total cross sections, elastic and inelastic scattering cross section measurements, and neutron induced fission cross sections. The inelastic scattering to the first few excited states in 56Fe was investigated by measuring the gamma production cross section with an HPGe detector. The neutron induced fission of 242Pu was studied using fast ionisation chambers with large homogeneous actinide deposits.

  20. Time-of-flight Extreme Environment Diffractometer at the Helmholtz-Zentrum Berlin.

    PubMed

    Prokhnenko, Oleksandr; Stein, Wolf-Dieter; Bleif, Hans-Jürgen; Fromme, Michael; Bartkowiak, Maciej; Wilpert, Thomas

    2015-03-01

    The Extreme Environment Diffractometer (EXED) is a new neutron time-of-flight instrument at the BER II research reactor at the Helmholtz-Zentrum Berlin, Germany. Although EXED is a special-purpose instrument, its early construction made it available for users as a general-purpose diffractometer. In this respect, EXED became one of the rare examples, where the performance of a time-of-flight diffractometer at a continuous source can be characterized. In this paper, we report on the design and performance of EXED with an emphasis on the unique instrument capabilities. The latter comprise variable wavelength resolution and wavelength band, control of the incoming beam divergence, the possibility to change the angular positions of detectors and their distance to the sample, and use of event recording and offline histogramming. These features combined make EXED easily tunable to the requirements of a particular problem, from conventional diffraction to small angle neutron scattering. The instrument performance is demonstrated by several reference measurements and user experiments.

  1. Time-of-flight Extreme Environment Diffractometer at the Helmholtz-Zentrum Berlin

    SciTech Connect

    Prokhnenko, Oleksandr Stein, Wolf-Dieter; Bleif, Hans-Jürgen; Fromme, Michael; Bartkowiak, Maciej; Wilpert, Thomas

    2015-03-15

    The Extreme Environment Diffractometer (EXED) is a new neutron time-of-flight instrument at the BER II research reactor at the Helmholtz-Zentrum Berlin, Germany. Although EXED is a special-purpose instrument, its early construction made it available for users as a general-purpose diffractometer. In this respect, EXED became one of the rare examples, where the performance of a time-of-flight diffractometer at a continuous source can be characterized. In this paper, we report on the design and performance of EXED with an emphasis on the unique instrument capabilities. The latter comprise variable wavelength resolution and wavelength band, control of the incoming beam divergence, the possibility to change the angular positions of detectors and their distance to the sample, and use of event recording and offline histogramming. These features combined make EXED easily tunable to the requirements of a particular problem, from conventional diffraction to small angle neutron scattering. The instrument performance is demonstrated by several reference measurements and user experiments.

  2. Status and outlook of the neutron time-of-flight facility n_TOF at CERN

    NASA Astrophysics Data System (ADS)

    Gunsing, F.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Álvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; de Albornoz, A. Carrillo; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Dolfini, R.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Frais-Koelbl, H.; Fujii, K.; Furman, W.; Goncalves, I.; González-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krtička, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Martínez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescher, M.; Wisshak, K.; n TOF Collaboration

    2007-08-01

    The neutron time-of-flight facility n_TOF at CERN, fully operational since 2002, combines a high instantaneous neutron flux with high energy resolution. The wide energy range and the high neutron flux per time-of-flight burst result in a much enhanced signal to background ratio for neutron capture of radioactive isotopes and makes this facility well suited for the measurement of high quality neutron-induced reaction cross-sections. Neutrons are created by spallation reactions induced by a pulsed 20 GeV/c proton beam impinging on a lead target. A 5 cm water slab surrounding the lead target serves as a coolant and at the same time as a moderator of the spallation neutron spectrum, providing a wide energy spectrum from 0.1 eV to about 250 MeV. By the end of 2005, a first phase of data taking has been successfully terminated. Fission and capture experiments have been performed on a variety of isotopes of interest for nuclear astrophysics, advanced nuclear technologies and for basic nuclear physics. The instrumentation developed for this facility consists of parallel plate avalanche counter and fission ionization chamber detectors for the fission experiments and of low mass C6D6 detectors and a 4 pi BaF2 total absorption calorimeter for capture experiments. A new data acquisition system, based on sampling of the detector signals, has been developed to cope with the high count rates and to minimize the effective dead time to only a few tens of nanosecond. A second phase of data taking is planned to start in 2007, after an upgrade of the spallation target. On the longer term, the construction of a flight path at 20 m resulting in an increased neutron flux of about a factor of 100 opens new possibilities.

  3. Accurate Fiber Length Measurement Using Time-of-Flight Technique

    NASA Astrophysics Data System (ADS)

    Terra, Osama; Hussein, Hatem

    2016-06-01

    Fiber artifacts of very well-measured length are required for the calibration of optical time domain reflectometers (OTDR). In this paper accurate length measurement of different fiber lengths using the time-of-flight technique is performed. A setup is proposed to measure accurately lengths from 1 to 40 km at 1,550 and 1,310 nm using high-speed electro-optic modulator and photodetector. This setup offers traceability to the SI unit of time, the second (and hence to meter by definition), by locking the time interval counter to the Global Positioning System (GPS)-disciplined quartz oscillator. Additionally, the length of a recirculating loop artifact is measured and compared with the measurement made for the same fiber by the National Physical Laboratory of United Kingdom (NPL). Finally, a method is proposed to relatively correct the fiber refractive index to allow accurate fiber length measurement.

  4. The time-of-flight wall for the HADES spectrometer

    SciTech Connect

    Agodi, C.; Bassi, A.; Bassini, R.

    1998-06-01

    In the framework of the HADES (High Acceptance DiElectron Spectrometer) collaboration the authors are developing the Time Of Flight (TOF) wall subdetector. In order to efficiently select events with e{sup +}e{sup {minus}} pairs produced in the nuclear matter, the TOF wall must be able to resolve electrons from pions up to 0.5 GeV/c and from protons up to 2 GeV/c. Because the short flight path of about 2m requires a 100--150 ps time resolution, the authors are building a granular system made of scintillator rods readout on both ends by means of photomultipliers, capable of such performance.

  5. Chern numbers hiding in time-of-flight images

    SciTech Connect

    Zhao Erhai; Satija, Indubala I.; Bray-Ali, Noah; Williams, Carl J.; Spielman, I. B.

    2011-12-15

    We present a technique for detecting topological invariants--Chern numbers--from time-of-flight images of ultracold atoms. We show that the Chern numbers of integer quantum Hall states of lattice fermions leave their fingerprints in the atoms' momentum distribution. We analytically demonstrate that the number of local maxima in the momentum distribution is equal to the Chern number in two limiting cases, for large hopping anisotropy and in the continuum limit. In addition, our numerical simulations beyond these two limits show that these local maxima persist for a range of parameters. Thus, an everyday observable in cold atom experiments can serve as a useful tool to characterize and visualize quantum states with nontrivial topology.

  6. Time-of-flight Fourier Spectrometry with UCN

    NASA Astrophysics Data System (ADS)

    Kulin, G. V.; Frank, A. I.; Goryunov, S. V.; Geltenbort, P.; Jentschel, M.; Bushuev, V. A.; Lauss, B.; Schmidt-Wellenburg, Ph.; Panzarella, A.; Fuchs, Y.

    2016-09-01

    The report presents the first experience of using a time-of-flight Fourier spectrometer of ultracold neutrons (UCN). The description of the spectrometer design and first results of its testing are presented. The results of the first experiments show that the spectrometer may be used for obtaining UCN energy spectra in the energy range of 60÷200 neV with a resolution of about 5 neV. The application of TOF Fourier spectrometry technique allowed us to obtain the energy spectra from the diffraction of monochromatic ultracold neutrons on a moving grating. Lines of 0, +1 and +2 diffraction orders were simultaneously recorded, which had previously been impossible to be done by other methods. These results have made it possible to make a comparison with the recent theoretical calculations based on the dynamical theory of neutron diffraction on a moving phase grating.

  7. Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak.

    PubMed

    Cui, Z Q; Chen, Z J; Xie, X F; Peng, X Y; Hu, Z M; Du, T F; Ge, L J; Zhang, X; Yuan, X; Xia, Z W; Hu, L Q; Zhong, G Q; Lin, S Y; Wan, B N; Fan, T S; Chen, J X; Li, X Q; Zhang, G H

    2014-11-01

    The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G.

  8. High-resolution reflecting time-of-flight momentum and energy mapping system

    SciTech Connect

    Wang Chao; Kang Yifan; Weaver, Larry; Chang Zenghu

    2009-07-15

    A new system to map electron momentum and energy is proposed. A reflecting electrode is introduced into a time-of-flight (TOF) system whose decelerating electric field sends all the electrons back to a position-sensitive detector close to but behind the source of the electrons. The longer flying distance that results makes it possible to significantly improve the energy-resolved performance, especially in the higher energy region. The dependence of the new TOF system on its characteristic parameters is analyzed, along with its application to attosecond streak cameras. Experimental results verified a relative energy resolution better than 0.2 eV for 22 eV electrons and also revealed the availability of the improved relative energy resolution smaller than 1.0% for electron energy ranging from 30 to 40 eV.

  9. A Design for a Compact Time-of-Flight Mass Spectrometer

    SciTech Connect

    Manard, M.

    2012-10-01

    The design of a prototype, compact time-of-flight (TOF) mass spectrometer (MS) is described. The system primarily consists of an ion acceleration/focusing/steering assembly (AFSA), an 8 cm field-free region, a 4 cm, dual-stage reflectron and a miniature microchannel plate detector. Consequently, the resulting flight length of the system is 12 cm. The system has been designed with the capability to sample directly from atmosphere at ambient pressures. This is accomplished through the use of an electrodynamic ion funnel, housed in an intermediate-vacuum chamber that is coupled to the inlet of the TOF chamber. TOF spectra were obtained using noble gases (Ar, Kr and Xe) as test chemicals. These measured flight times were used to probe the performance of the instrument. A temporal resolution (tflight/Δt) of approximately 125, acquired using 129Xe+, has been measured for the system.

  10. Calibration and operation of a neutron time-of-flight scintillator array on nova

    SciTech Connect

    Chrien, R.E.; Klare, K.A.; Murphy, T.J.

    1995-12-31

    The Tion diagnostic is a 1020-channel scintillator array on the Nova laser at Livermore. It measures the arrival time of single d-d or d-t neutrons at 27 m from the target with a time resolution of 4 ns. The effect of neutron scattering has been obtained from Monte-Carlo neutron transport simulations and the scattered response is convolved with a gaussian source to fit the data. The data analysis has been checked using targets which produce roughly equal numbers of d-t and d-d counts. The spectrum from Tion is in reasonable agreement with conventional neutron time-of-flight detectors at yields above 3 x 10{sup 8}.

  11. A real time scintillating fiber Time of Flight spectrometer for LINAC photoproduced neutrons

    NASA Astrophysics Data System (ADS)

    Maspero, M.; Berra, A.; Conti, V.; Giannini, G.; Ostinelli, A.; Prest, M.; Vallazza, E.

    2015-03-01

    The use of high-energy (> 8 MeV) LINear ACcelerators (LINACs) for medical cancer treatments causes the photoproduction of secondary neutrons, whose unwanted dose to the patient has to be calculated. The characterization of the neutron spectra is necessary to allow the dosimetric evaluation of the neutron beam contamination. The neutron spectrum in a hospital environment is usually measured with integrating detectors such as bubble dosimeters, Thermo Luminescent Dosimeters (TLDs) or Bonner Spheres, which integrate the information over a time interval and an energy one. This paper presents the development of a neutron spectrometer based on the Time of Flight (ToF) technique in order to perform a real time characterization of the neutron contamination. The detector measures the neutron spectrum exploiting the fact that the LINAC beams are pulsed and arranged in bunches with a rate of 100-300 Hz depending on the beam type and energy. The detector consists of boron loaded scintillating fibers readout by a MultiAnode PhotoMultiplier Tube (MAPMT). A detailed description of the detector and the acquisition system together with the results in terms of ToF spectra and number of neutrons with a Varian Clinac iX are presented.

  12. Time-of-flight thermal flowrate sensor for lab-on-chip applications.

    PubMed

    Berthet, Helene; Jundt, Jacques; Durivault, Jerome; Mercier, Bruno; Angelescu, Dan

    2011-01-21

    We describe a thermal microflowrate sensor for measuring liquid flow velocity in microfluidic channels, which is capable of providing a highly accurate response independent of the thermal and physical properties of the working liquid. The sensor consists of a rectangular channel containing a heater and several temperature detectors microfabricated on suspended silicon bridges. Heat pulses created by the heater are advected downstream by the flow and are detected using the temperature detector bridges. By injecting a pseudo-stochastic thermal signal at the heater and performing a cross correlation between the detected and the injected signals, we can measure the single-pulse response of the system with excellent signal-to-noise ratio and hence deduce the thermal signal time-of-flight from heater to detector. Combining results from several detector bridges allows us to eliminate diffusion effects, and thus calculate the flow velocity with excellent accuracy and linearity over more than two orders of magnitude. The experimental results obtained with several test fluids closely agree with data from finite element analysis. We developed a phenomenological model which supports and explains the observed sensor response. Several fully functional sensor prototypes were built and characterized, proving the feasibility and providing a critical component to microfluidic lab-on-chip applications where accurate flow measurements are of importance.

  13. Development of EndoTOFPET-US, a multi-modal endoscope for ultrasound and time of flight positron emission tomography

    NASA Astrophysics Data System (ADS)

    Pizzichemi, M.

    2014-02-01

    The EndoTOFPET-US project aims at delevoping a multi-modal imaging device that combines Ultrasound with Time-Of-Flight Positron Emission Tomography into an endoscopic imaging device. The goal is to obtain a coincidence time resolution of about 200 ps FWHM and sub-millimetric spatial resolution for the PET head, integrating the components in a very compact detector suitable for endoscopic use. The scanner will be exploited for the clinical test of new bio-markers especially targeted for prostate and pancreatic cancer as well as for diagnostic and surgical oncology. This paper focuses on the status of the Time-Of-Flight Positron Emission Tomograph under development for the EndoTOFPET-US project.

  14. Status of the front-end-electronics for the time-of-flight measurements at the MPD experiment

    NASA Astrophysics Data System (ADS)

    Buryakov, M. G.; Babkin, V. A.; Golovatyuk, V. M.; Volgin, S. V.; Rumyantsev, M. M.

    2016-09-01

    The preamplifier based on the ASIC NINO for the Time of Flight system (TOF) of MPD/NICA was developed and tested. The signal is read from both sides of the strip of the multi gap Resistive Plate Chamber (MRPC). In total there are around 14000 channels of electronics. To measure time of flight of secondary particles from collision of heavy ions on the collider NICA the Time over Threshold (ToT) method is used. According to the bench tests the preamplifier board showed stable work and good time resolution <10 ps for one channel. It was also tested at the test beam facility of the Nuclotron. The time resolution of the TOF detector which used the described preamplifier was reached ˜42 ps.

  15. The ALICE Experiment at the LHC and the Mexican Contribution

    SciTech Connect

    Herrera Corral, G.

    2007-06-19

    The final installation of the detectors that form ALICE has started on year 2005. The first device of ALICE that was completed and set up to work was the Cosmic Ray Detector. The V0A detector will be installed and commissioned on the summer of 2007. These two detectors were designed and built in Mexico. Here we give a very general description of these two devices.

  16. Video Guidance Sensor and Time-of-Flight Rangefinder

    NASA Technical Reports Server (NTRS)

    Bryan, Thomas; Howard, Richard; Bell, Joseph L.; Roe, Fred D.; Book, Michael L.

    2007-01-01

    A proposed video guidance sensor (VGS) would be based mostly on the hardware and software of a prior Advanced VGS (AVGS), with some additions to enable it to function as a time-of-flight rangefinder (in contradistinction to a triangulation or image-processing rangefinder). It would typically be used at distances of the order of 2 or 3 kilometers, where a typical target would appear in a video image as a single blob, making it possible to extract the direction to the target (but not the orientation of the target or the distance to the target) from a video image of light reflected from the target. As described in several previous NASA Tech Briefs articles, an AVGS system is an optoelectronic system that provides guidance for automated docking of two vehicles. In the original application, the two vehicles are spacecraft, but the basic principles of design and operation of the system are applicable to aircraft, robots, objects maneuvered by cranes, or other objects that may be required to be aligned and brought together automatically or under remote control. In a prior AVGS system of the type upon which the now-proposed VGS is largely based, the tracked vehicle is equipped with one or more passive targets that reflect light from one or more continuous-wave laser diode(s) on the tracking vehicle, a video camera on the tracking vehicle acquires images of the targets in the reflected laser light, the video images are digitized, and the image data are processed to obtain the direction to the target. The design concept of the proposed VGS does not call for any memory or processor hardware beyond that already present in the prior AVGS, but does call for some additional hardware and some additional software. It also calls for assignment of some additional tasks to two subsystems that are parts of the prior VGS: a field-programmable gate array (FPGA) that generates timing and control signals, and a digital signal processor (DSP) that processes the digitized video images. The

  17. Chern Numbers Hiding in Time of Flight Images

    NASA Astrophysics Data System (ADS)

    Satija, Indubala; Zhao, Erhai; Ghosh, Parag; Bray-Ali, Noah

    2011-03-01

    Since the experimental realization of synthetic magnetic fields in neural ultracold atoms, transport measurement such as quantized Hall conductivity remains an open challenge. Here we propose a novel and feasible scheme to measure the topological invariants, namely the chern numbers, in the time of flight images. We study both the commensurate and the incommensurate flux, with the later being the main focus here. The central concept underlying our proposal is the mapping between the chern numbers and the size of the dimerized states that emerge when the two-dimensional hopping is tuned to the highly anisotropic limit. In a uncoupled double quantum Hall system exhibiting time reversal invariance, only odd-sized dimer correlation functions are non-zero and hence encode quantized spin current. Finally, we illustrate that inspite of highly fragmented spectrum, a finite set of chern numbers are meaningful. Our results are supported by direct numerical computation of transverse conductivity. NBA acknowledges support from a National Research Council postdoctoral research associateship.

  18. Time-of-flight observation of electron swarm in methane

    SciTech Connect

    Hasegawa, H.; Date, H.; Yoshida, K.; Shimozuma, M.

    2009-06-01

    This paper reports on the evolution of an isolated electron swarm, which is experimentally observed as spatial distributions at every moment. This observation is assumed to directly correspond to the conventional time-of-flight theory. We have measured the spatial distribution of electrons using a double-shutter technique in the drift tube, where a shutter electrode to collect electrons can be slid along the field (E/N) direction in order to capture a relative electron number at a certain range of location. As a typical parameter defined by this spatial distribution, the center-of-mass drift velocity (W{sub r}) is determined for methane gas. The result is compared with the mean-arrival-time drift velocity (W{sub m}) defined from the arriving electron number at fixed positions. We have also performed a theoretical analysis in which a Fourier transformed Boltzmann equation is solved to deduce both of the drift velocities from a dispersion relationship. The difference between W{sub r} and W{sub m} at high E/Ns (above 200 Td) is clearly ascertained in the experimental and theoretical investigations, which is attributable to the occurrence of ionization events.

  19. Update on time-of-flight PET imaging

    PubMed Central

    Surti, Suleman

    2015-01-01

    Time-of-flight (TOF) PET was initially introduced in the early days of PET. TOF PET scanners developed in the 1980s had limited sensitivity and spatial resolution, operated in 2D mode with septa, and used analytic image reconstruction methods. Current generation of TOF PET scanners have the highest sensitivity and spatial resolution ever achieved in commercial whole-body PET, operate in fully-3D mode, and use iterative reconstruction with full system modeling. Previously, it was shown that TOF provides a gain in image signal-to-noise-ratio (SNR) that is proportional to the square root of the object size divided by the system timing resolution. With oncologic studies being the primary application of PET, more recent work has shown that in modern TOF PET scanners there is an improved trade-off between lesion contrast, image noise, and total imaging time, leading to a combination of improved lesion detectability, reduced scan time or injected dose, and more accurate and precise lesion uptake measurement. The benefit of TOF PET is also higher for heavier patients, which leads to a more uniform clinical performance over all patient sizes. PMID:25525181

  20. Time-of-flight photoconductivity in polymer/graphene blends

    NASA Astrophysics Data System (ADS)

    Bratina, Gvido; Pavlica, Egon; Pathipati, Srinivasa Rao; Nawrocki, Robert; Penumala, Raveendra

    2015-03-01

    We have used time-of-flight (TOF) photoconductivity measurements to assess the electric charge transport parameters in thin layers of poly(3-hexyl thiophene-2,5-diyl) (P3HT) mixed with single and multiple-layer graphene nanoflakes. Thin layers were cast from a solution and two co-planar metal electrodes were deposited by vacuum evaporation on top. An electric field was set up between the electrodes A laser pulse was used to photogenerate charge carriers near the biased electrode, and time dependence of the photocurrent (I(t)) was measured at the opposite electrode. I(t) curves were confronted to I(t)s obtained by a Gaussian-disorder Monte Carlo simulations, adapted to thin-film geometry. The simulations included a position-dependent electric field between two coplanar electrodes, which importantly affects the charge carrier transport through the blend between the electrodes. Comparison between the simulated and measured I(t)s resulted in values for charge carrier mobility, average charge velocity and variation of charge velocity. Our results show that the hole mobility in blends is increased by more than an order of magnitude in comparison to the hole mobility of a neat layers of P3HT

  1. The high-resolution time-of-flight spectrometer TOFTOF

    NASA Astrophysics Data System (ADS)

    Unruh, Tobias; Neuhaus, Jürgen; Petry, Winfried

    2007-10-01

    The TOFTOF spectrometer is a multi-disc chopper time-of-flight spectrometer for cold neutrons at the research neutron source Heinz Maier-Leibnitz (FRM II). After five reactor cycles of routine operation the characteristics of the instrument are reported in this article. The spectrometer features an excellent signal to background ratio due to its remote position in the neutron guide hall, an elaborated shielding concept and an s-shaped curved primary neutron guide which acts i.a. as a neutron velocity filter. The spectrometer is fed with neutrons from the undermoderated cold neutron source of the FRM II leading to a total neutron flux of ˜1010n/cm2/s in the continuous white beam at the sample position distributed over a continuous and particularly broad wavelength spectrum. A high energy resolution is achieved by the use of high speed chopper discs made of carbon-fiber-reinforced plastic. In the combination of intensity, resolution and signal to background ratio the spectrometer offers new scientific prospects in the fields of inelastic and quasielastic neutron scattering.

  2. Development of position-sensitive time-of-flight spectrometer for fission fragment research

    SciTech Connect

    Arnold, C. W.; Tovesson, F.; Meierbachtol, K.; Bredeweg, T.; Jandel, M.; Jorgenson, H. J.; Laptev, A.; Rusev, G.; Shields, D. W.; White, M.; Blakeley, R. E.; Mader, D. M.; Hecht, A. A.

    2014-07-09

    A position-sensitive, high-resolution time-of-flight detector for fission fragments has been developed. The SPectrometer for Ion DEtermination in fission Research (SPIDER) is a 2E–2v spectrometer designed to measure the mass of light fission fragments to a single mass unit. The time pick-off detector pairs to be used in SPIDER have been tested with α-particles from 229Th and its decay chain and α-particles and spontaneous fission fragments from 252Cf. Each detector module is comprised of thin electron conversion foil, electrostatic mirror, microchannel plates, and delay-line anodes. Particle trajectories on the order of 700 mm are determined accurately to within 0.7 mm. Flight times were measured with 250 ps resolution FWHM. Computed particle velocities are accurate to within 0.06 mm/ns corresponding to a precision of 0.5%. As a result, an ionization chamber capable of 400 keV energy resolution coupled with the velocity measurements described here will pave the way for modestly efficient measurements of light fission fragments with unit mass resolution.

  3. Development of position-sensitive time-of-flight spectrometer for fission fragment research

    DOE PAGES

    Arnold, C. W.; Tovesson, F.; Meierbachtol, K.; ...

    2014-07-09

    A position-sensitive, high-resolution time-of-flight detector for fission fragments has been developed. The SPectrometer for Ion DEtermination in fission Research (SPIDER) is a 2E–2v spectrometer designed to measure the mass of light fission fragments to a single mass unit. The time pick-off detector pairs to be used in SPIDER have been tested with α-particles from 229Th and its decay chain and α-particles and spontaneous fission fragments from 252Cf. Each detector module is comprised of thin electron conversion foil, electrostatic mirror, microchannel plates, and delay-line anodes. Particle trajectories on the order of 700 mm are determined accurately to within 0.7 mm. Flightmore » times were measured with 250 ps resolution FWHM. Computed particle velocities are accurate to within 0.06 mm/ns corresponding to a precision of 0.5%. As a result, an ionization chamber capable of 400 keV energy resolution coupled with the velocity measurements described here will pave the way for modestly efficient measurements of light fission fragments with unit mass resolution.« less

  4. High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

    SciTech Connect

    Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; Kim, H.; Chen, C.; Kao, C.; Niessen, K.; Zatserklyaniy, A.; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

    2011-02-01

    We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage

  5. Investigation of a Multi-Anode Microchannel Plate PMT for Time-of-Flight PET.

    PubMed

    Choong, Woon-Seng

    2010-09-13

    We report on an investigation of a mulit-anode microchannel plate PMT for time-of-flight PET detector modules. The primary advantages of an MCP lie in its excellent timing properties (fast rise time and low transit time spread), compact size, and reasonably large active area, thus making it a good candidate for TOF applications. In addition, the anode can be segmented into an array of collection electrodes with fine pitch to attain good position sensitivity. In this paper, we investigate using the Photonis Planacon MCP-PMT with a pore size of 10 µm to construct a PET detector module, specifically for time-of-flight applications. We measure the single electron response by exciting the Planacon with pulsed laser diode. We also measure the performance of the Planacon as a PET detector by coupling a 4 mm × 4 mm × 10 mm LSO crystal to individual pixel to study its gain uniformity, energy resolution, and timing resolution. The rise time of the Planacon is 440 ps with pulse duration of about 1 ns. A transit time spread of 120 ps FWHM is achieved. The gain is fairly uniform across the central region of the Planacon, but drops off by as much as a factor of 2.5 around the edges. The energy resolution is fairly uniform across the Planacon with an average value of 18.6±0.7% FWHM. While the average timing resolution of 252±7 ps FWHM is achieved in the central region of the Planacon, it degrades to 280±9 ps FWHM for edge pixels and 316±15 ps FWHM for corner pixels. We compare the results with measurements performed with a fast timing conventional PMT (Hamamatsu R-9800). We find that the R9800, which has significantly higher PDE, has a better timing resolution than the Planacon. Furthermore, we perform detector simulations to calculate the improvement that can be achieved with a higher PDE Planacon. The calculation shows that the Planacon can achieve significantly better timing resolution if it can attain the same PDE as the R-9800, while only a 30% improvement is needed

  6. Development of grazing incidence devices for space-borne time of flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Cadu, A.; Devoto, P.; Louarn, P.; Sauvaud, J.-A.

    2012-04-01

    Time of flight mass spectrometer is widely used to study space plasmas in planetary and solar missions. This space-borne instrument selects ions in function of their energy through an electrostatic analyzer. Particles are then post-accelerated to energies in the range of 20 keV to cross a carbon foil. At the foil exit, electrons are emitted and separated from ion beam in the time of flight section. A first detector (a Micro-Channel Plate or MCP) emits a start signal at electron arrival and a second one emits a stop signal at incident ion end of path. The time difference gives the speed of the particle and its mass can be calculated, knowing its initial energy. However, current instruments suffer from strong limitations. The post acceleration needs very high voltage power supplies which are heavy, have a high power consumption and imply technical constraints for the development. A typical instrument weighs from 5 to 6 kg, includes a 20 kV power supply, consumes a least 5 W and encounters corona effect and electrical breakdown problems. Moreover, despite the particle high energy range, scattering and straggling phenomena in the carbon foil significantly reduce the instrument overall resolution. Some methods, such as electrostatic focus lenses or reflectrons, really improve mass separation but global system efficiency remains very low because of the charge state dependence of such devices. The main purpose of our work is to replace carbon foil by grazing incidence MCP's - also known as MPO's, for Micro Pore Optics - for electron emission. Thus, incident particles would back-scatter onto the channel inner surface with an angle of a few degrees. With this solution, we can decrease dispersion sources and lower the power supplies to post accelerate ions. The result would be a lighter and simpler instrument with a substantial resolution improvement. We have first simulated MPO's behavior with TRIM and MARLOWE Monte-Carlo codes. Energy scattering and output angle computed

  7. High mass resolution isochronous time-of-flight spectrograph for three-dimensional space plasma measurements (abstract)

    SciTech Connect

    Moebius, E. ); Bochsler, P. ); Ghielmetti, A.G. ); Hamilton, D.C. )

    1990-10-01

    By combining a toroidal electrostatic analyzer with a novel cylindrically symmetric isochronous time-of-flight mass spectrometer, we have developed an instrument that simultaneously determines the three-dimensional distribution function of ions and differentiates species. The ion mass is determined to high resolution ({ital M}/{Delta}{ital M}{gt}50) from the time of flight within a harmonic field configuration defined by hyperboloid equipotential surfaces. A second conventional time-of-flight channel makes use of particles leaving the thin entrance foil as neutrals. An additional solid state detector in which the neutrals are stopped allows the total energy and thereby the ionic charge of the incident ions to be determined as well. Information from the neutral and the ion channels can be combined to determine the total mass of an incident molecular ion and the mass of one atomic fragment. This also removes the ambiguity between molecular ions and isotopic species of the same mass. A laboratory prototype has been used to demonstrate the feasibility of the principle of operation.

  8. Sensors for Using Times of Flight to Measure Flow Velocities

    NASA Technical Reports Server (NTRS)

    Fralick, Gutave; Wrbanek, John D.; Hwang, Danny; Turso, James

    2006-01-01

    Thin-film sensors for measuring flow velocities in terms of times of flight are undergoing development. These sensors are very small and can be mounted flush with surfaces of airfoils, ducts, and other objects along which one might need to measure flows. Alternatively or in addition, these sensors can be mounted on small struts protruding from such surfaces for acquiring velocity measurements at various distances from the surfaces for the purpose of obtaining boundary-layer flow-velocity profiles. These sensors are related to, but not the same as, hot-wire anemometers. Each sensor includes a thin-film, electrically conductive loop, along which an electric current is made to flow to heat the loop to a temperature above that of the surrounding fluid. Instantaneous voltage fluctuations in segments of the loop are measured by means of electrical taps placed at intervals along the loop. These voltage fluctuations are caused by local fluctuations in electrical resistance that are, in turn, caused by local temperature fluctuations that are, in turn, caused by fluctuations in flow-induced cooling and, hence, in flow velocity. The differential voltage as a function of time, measured at each pair of taps, is subjected to cross-correlation processing with the corresponding quantities measured at other pairs of taps at different locations on the loop. The cross-correlations yield the times taken by elements of fluid to travel between the pairs of taps. Then the component of velocity along the line between any two pairs of taps is calculated simply as the distance between the pairs of taps divided by the travel time. Unlike in the case of hot-wire anemometers, there is no need to obtain calibration data on voltage fluctuations versus velocity fluctuations because, at least in principle, the correlation times are independent of the calibration data.

  9. LVGEMS Time-of-Flight Mass Spectrometry on Satellites

    NASA Technical Reports Server (NTRS)

    Herrero, Federico

    2013-01-01

    NASA fs investigations of the upper atmosphere and ionosphere require measurements of composition of the neutral air and ions. NASA is able to undertake these observations, but the instruments currently in use have their limitations. NASA has extended the scope of its research in the atmosphere and now requires more measurements covering more of the atmosphere. Out of this need, NASA developed multipoint measurements using miniaturized satellites, also called nanosatellites (e.g., CubeSats), that require a new generation of spectrometers that can fit into a 4 4 in. (.10 10 cm) cross-section in the upgraded satellites. Overall, the new mass spectrometer required for the new depth of atmospheric research must fulfill a new level of low-voltage/low-power requirements, smaller size, and less risk of magnetic contamination. The Low-Voltage Gated Electrostatic Mass Spectrometer (LVGEMS) was developed to fulfill these requirements. The LVGEMS offers a new spectrometer that eliminates magnetic field issues associated with magnetic sector mass spectrometers, reduces power, and is about 1/10 the size of previous instruments. LVGEMS employs the time of flight (TOF) technique in the GEMS mass spectrometer previously developed. However, like any TOF mass spectrometer, GEMS requires a rectangular waveform of large voltage amplitude, exceeding 100 V -- that means that the voltage applied to one of the GEMS electrodes has to change from 0 to 100 V in a time of only a few nanoseconds. Such electronic speed requires more power than can be provided in a CubeSat. In the LVGEMS, the amplitude of the rectangular waveform is reduced to about 1 V, compatible with digital electronics supplies and requiring little power.

  10. Pulse processing routines for neutron time-of-flight data

    NASA Astrophysics Data System (ADS)

    Žugec, P.; Weiß, C.; Guerrero, C.; Gunsing, F.; Vlachoudis, V.; Sabate-Gilarte, M.; Stamatopoulos, A.; Wright, T.; Lerendegui-Marco, J.; Mingrone, F.; Ryan, J. A.; Warren, S. G.; Tsinganis, A.; Barbagallo, M.

    2016-03-01

    A pulse shape analysis framework is described, which was developed for n_TOF-Phase3, the third phase in the operation of the n_TOF facility at CERN. The most notable feature of this new framework is the adoption of generic pulse shape analysis routines, characterized by a minimal number of explicit assumptions about the nature of pulses. The aim of these routines is to be applicable to a wide variety of detectors, thus facilitating the introduction of the new detectors or types of detectors into the analysis framework. The operational details of the routines are suited to the specific requirements of particular detectors by adjusting the set of external input parameters. Pulse recognition, baseline calculation and the pulse shape fitting procedure are described. Special emphasis is put on their computational efficiency, since the most basic implementations of these conceptually simple methods are often computationally inefficient.

  11. Duty cycle and modulation efficiency of two-channel Hadamard transform time-of-flight mass spectrometry.

    PubMed

    Yoon, Oh Kyu; Zuleta, Ignacio A; Kimmel, Joel R; Robbins, Matthew D; Zare, Richard N

    2005-11-01

    Hadamard transform time-of-flight mass spectrometry (HT-TOFMS) is based on the pseudorandom gating of ion packets into a time-of-flight mass-to-charge analyzer. In its typical implementation, the technique is able to monitor continuous ion sources with a 50% duty cycle, independent of all other figures of merit. Recently, we have demonstrated that the duty cycle can be extended to 100% using patterned, two-channel detection. Two-channel HT-TOFMS involves the simultaneous optimization of paired one-channel experiments and imposes more stringent conditions to achieve high-quality spectra. An ion modulation device, known as Bradbury-Nielson Gate (BNG), is central to HT-TOFMS. It is an ideal deflection plate, capable of transmitting or deflecting an ion beam according to a known binary sequence without changing the times-of-flight of the ions. Analytical equations are derived that accurately describe the ion modulation process of the BNG as confirmed by good agreement with SimIon simulations and ion beam imaging experiments. From these expressions, the duty cycle and ion modulation efficiency were calculated for various BNG parameters, ion beam characteristics, and detector dimensions, which permit the optimum conditions to be chosen for the two-channel experiment. We conclude that the outer detector should be three times the maximum deflection angle to detect all deflected ions (100% duty cycle) and that the difference between the modulated ion counts in the sequence elements 0 and 1 should be maximized to achieve high modulation efficiency. This condition is best achieved by tight focusing of the ion beam in the center of the inner detector. When both channels are optimized, the two-channel advantage can be exploited to achieve a further improvement over a single-channel experiment.

  12. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    SciTech Connect

    Herraiz, J. L.; Sitek, A.

    2015-11-15

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data.

  13. Study of Scattered Background Neutron in NIF and Time-of Flight (TOF) to Measure Neutron

    SciTech Connect

    Song, P; Moran, M; Phillips, T; Lerche, R; Koch, J; Eder, D

    2005-08-31

    Some of the planned core diagnostics for National Ignition Facility (NIF) will use neutron time-of-flight (TOF) spectroscopy techniques to gather information for primary neutron yield measurement or neutron imaging. This technique has been widely and routinely used at other laser facilities including Nova and Omega. TOF methods will also be used to observe target fuel areal density <{rho}R> (radial integral of density) via measuring the number of primary 14.1 MeV neutrons that are down-scattered to lower energies by nuclear collisions inside the compressed target core. The substantially larger target chamber size and higher neutron yield for NIF raises issues related to the large number of scattered neutrons produced by high yield deuterium-tritium (D-T) shots at NIF. The effect of primary neutrons scattered by the walls of the massive target chamber and structures both inside and outside the chamber will contribute a significant scattered background signal when trying to determine the number of neutrons down-scattered from the target core. The optimum detector locations outside the target chamber or target bay wall will be proposed. Appropriate collimators at the chamber port and the bay wall (between the neutron source at target chamber center (TCC) and detector) that maximize detection of signal neutrons while minimizing the background from scattered neutrons and neutron induced gamma rays will also be presented.

  14. Sensitivity estimation in time-of-flight list-mode positron emission tomography

    PubMed Central

    Herraiz, J. L.; Sitek, A.

    2015-01-01

    Purpose: An accurate quantification of the images in positron emission tomography (PET) requires knowing the actual sensitivity at each voxel, which represents the probability that a positron emitted in that voxel is finally detected as a coincidence of two gamma rays in a pair of detectors in the PET scanner. This sensitivity depends on the characteristics of the acquisition, as it is affected by the attenuation of the annihilation gamma rays in the body, and possible variations of the sensitivity of the scanner detectors. In this work, the authors propose a new approach to handle time-of-flight (TOF) list-mode PET data, which allows performing either or both, a self-attenuation correction, and self-normalization correction based on emission data only. Methods: The authors derive the theory using a fully Bayesian statistical model of complete data. The authors perform an initial evaluation of algorithms derived from that theory and proposed in this work using numerical 2D list-mode simulations with different TOF resolutions and total number of detected coincidences. Effects of randoms and scatter are not simulated. Results: The authors found that proposed algorithms successfully correct for unknown attenuation and scanner normalization for simulated 2D list-mode TOF-PET data. Conclusions: A new method is presented that can be used for corrections for attenuation and normalization (sensitivity) using TOF list-mode data. PMID:26520759

  15. Highlights from ALICE

    NASA Astrophysics Data System (ADS)

    Giubellino, Paolo

    The LHC has delivered for the first time collisions of Nuclei in November 2010, at an energy of 2.76 TeV per nucleon pair, which represents a jump of more than an order of magnitude over the highest energy nuclear collisions ever studied before. The high energy, the quality of the state-of-the art detectors, and the readiness of the experimental collaborations at the LHC have allowed a rich harvest of important scientific results. In this lecture a short overview will be given of how the results from the LHC, and in particular from the ALICE experiment, have provided new insight on the properties of matter under extreme conditions of temperature and pressure, analogous to the conditions present in the early phases of the evolution of the Universe. Results from the proton-nucleus run, which took place in early 2013, will also be presented. Finally, a very short outlook to the future will be given.

  16. Results from the commissioning of a multi-modal endoscope for ultrasound and time of flight PET

    SciTech Connect

    Bugalho, Ricardo

    2015-07-01

    The EndoTOFPET-US collaboration has developed a multi-modal imaging system combining Ultrasound with Time-of-Flight Positron Emission Tomography into an endoscopic imaging device. The objective of the project is to obtain a coincidence time resolution of about 200 ps FWHM and to achieve about 1 mm spatial resolution of the PET system, while integrating all the components in a very compact detector suitable for endoscopic use. This scanner aims to be exploited for diagnostic and surgical oncology, as well as being instrumental in the clinical test of new biomarkers especially targeted for prostate and pancreatic cancer. (authors)

  17. SYNCHROTRON RADIATION, FREE ELECTRON LASER, APPLICATION OF NUCLEAR TECHNOLOGY, ETC. Physical design of positronium time of flight spectroscopy apparatus

    NASA Astrophysics Data System (ADS)

    Jiang, Xiao-Pan; Zhang, Zi-Liang; Qin, Xiu-Bo; Yu, Run-Sheng; Wang, Bao-Yi

    2010-12-01

    Positronium time of flight spectroscopy (Ps-TOF) is an effective technique for porous material research. It has advantages over other techniques for analyzing the porosity and pore tortuosity of materials. This paper describes a design for Ps-TOF apparatus based on the Beijing intense slow positron beam, supplying a new material characterization technique. In order to improve the time resolution and increase the count rate of the apparatus, the detector system is optimized. For 3 eV o-Ps, the time broadening is 7.66 ns and the count rate is 3 cps after correction.

  18. EndoTOFPET-US - A Miniaturised Calorimeter for Endoscopic Time-of-Flight Positron Emission Tomography

    NASA Astrophysics Data System (ADS)

    Zvolský, Milan; EndoTOFPET-US Collaboration

    2015-02-01

    In the scope of the EndoTOFPET-US project, a novel multimodal device for Ultrasound (US) Endoscopy and Positron Emission Tomography (PET) is being developed. The project aims at detecting and quantifying morphologic and functional markers and developing new biomarkers for pancreas and prostate oncology. Exploiting the Time-of-Flight (TOF) information of the gamma rays allows for a more sensitive, more precise and lower radiation- dose imaging and intervention on small internal structures. The detection of the gamma rays is realised with the help of scintillator crystals with Silicon Photomultiplier (SiPM) read-out, aiming at a coincidence time resolution of 200 ps and a spatial resolution of ≈ 1 mm. For the endoscopic detector, digital SiPMs are utilised for the first time in an instrument planned for clinical applications. The functionality of the instrument as well as the challenges that accompany the high miniaturisation of the endoscopic detector and the asymmetric and variable geometry of the system, are presented. The demands on the system involve the fields of scintillating crystallography, ultra-fast photon detection, highly integrated electronics, system integration as well as image reconstruction. The single detector components have been fully characterised and are performing up to specifications. Two dedicated ASIC chips have been developed for the project. The first PET images have been acquired with a test setup that consists solely of hardware and software developed within the collaboration and demonstrate that the data acquisition and reconstruction chain is operational. In this talk, the characterisation of the single components and the status of the detector integration and comissioning is presented.

  19. High-performance electronics for time-of-flight PET systems.

    PubMed

    Choong, W-S; Peng, Q; Vu, C Q; Turko, B T; Moses, W W

    2013-01-01

    We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr3 crystals respectively.

  20. High-performance electronics for time-of-flight PET systems

    NASA Astrophysics Data System (ADS)

    Choong, W.-S.; Peng, Q.; Vu, C. Q.; Turko, B. T.; Moses, W. W.

    2013-01-01

    We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr3 crystals respectively.

  1. ALICE and The state of matter at LHC

    ScienceCinema

    None

    2016-07-12

    Assembly and installation of ALICE, the LHC heavy ion experiment dedicated to the study of matter at extreme temperature and pressure, is nearing completion and the commissioning of the detector is well under way. A good time to look back, to the making of ALICE, and to look forward, to the first physics with proton and heavy ion beams.

  2. Reconstruction of Time-Resolved Neutron Energy Spectra in Z-Pinch Experiments Using Time-of-flight Method

    SciTech Connect

    Rezac, K.; Klir, D.; Kubes, P.; Kravarik, J.

    2009-01-21

    We present the reconstruction of neutron energy spectra from time-of-flight signals. This technique is useful in experiments with the time of neutron production in the range of about tens or hundreds of nanoseconds. The neutron signals were obtained by a common hard X-ray and neutron fast plastic scintillation detectors. The reconstruction is based on the Monte Carlo method which has been improved by simultaneous usage of neutron detectors placed on two opposite sides from the neutron source. Although the reconstruction from detectors placed on two opposite sides is more difficult and a little bit inaccurate (it followed from several presumptions during the inclusion of both sides of detection), there are some advantages. The most important advantage is smaller influence of scattered neutrons on the reconstruction. Finally, we describe the estimation of the error of this reconstruction.

  3. SENJU: a new time-of-flight single-crystal neutron diffractometer at J-PARC.

    PubMed

    Ohhara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; Kaneko, Koji; Kawasaki, Takuro; Tamura, Itaru; Nakao, Akiko; Hanashima, Takayasu; Munakata, Koji; Moyoshi, Taketo; Kuroda, Tetsuya; Kimura, Hiroyuki; Sakakura, Terutoshi; Lee, Chang-Hee; Takahashi, Miwako; Ohshima, Ken-Ichi; Kiyotani, Tamiko; Noda, Yukio; Arai, Masatoshi

    2016-02-01

    SENJU is a new single-crystal time-of-flight neutron diffractometer installed at BL18 at the Materials and Life Science Experimental Facility of the Japan Accelerator Research Complex (J-PARC). The diffractometer was designed for precise crystal and magnetic structure analyses under multiple extreme sample environments such as low temperature, high pressure and high magnetic field, and for diffraction measurements of small single crystals down to 0.1 mm(3) in volume. SENJU comprises three choppers, an elliptical shape straight supermirror guide, a vacuum sample chamber and 37 scintillator area detectors. The moderator-to-sample distance is 34.8 m, and the sample-to-detector distance is 800 mm. The wavelength of incident neutrons is 0.4-4.4 Å (first frame). Because short-wavelength neutrons are available and the large solid angle around the sample position is covered by the area detectors, a large reciprocal space can be simultaneously measured. Furthermore, the vacuum sample chamber and collimator have been designed to produce a very low background level. Thus, the measurement of a small single crystal is possible. As sample environment devices, a newly developed cryostat with a two-axis (ω and φ axes) goniometer and some extreme environment devices, e.g. a vertical-field magnet, high-temperature furnace and high-pressure cell, are available. The structure analysis of a sub-millimetre size (0.1 mm(3)) single organic crystal, taurine, and a magnetic structure analysis of the antiferromagnetic phase of MnF2 have been performed. These results demonstrate that SENJU can be a powerful tool to promote materials science research.

  4. SENJU: a new time-of-flight single-crystal neutron diffractometer at J-PARC

    PubMed Central

    Ohhara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; Kaneko, Koji; Kawasaki, Takuro; Tamura, Itaru; Nakao, Akiko; Hanashima, Takayasu; Munakata, Koji; Moyoshi, Taketo; Kuroda, Tetsuya; Kimura, Hiroyuki; Sakakura, Terutoshi; Lee, Chang-Hee; Takahashi, Miwako; Ohshima, Ken-ichi; Kiyotani, Tamiko; Noda, Yukio; Arai, Masatoshi

    2016-01-01

    SENJU is a new single-crystal time-of-flight neutron diffractometer installed at BL18 at the Materials and Life Science Experimental Facility of the Japan Accelerator Research Complex (J-PARC). The diffractometer was designed for precise crystal and magnetic structure analyses under multiple extreme sample environments such as low temperature, high pressure and high magnetic field, and for diffraction measurements of small single crystals down to 0.1 mm3 in volume. SENJU comprises three choppers, an elliptical shape straight supermirror guide, a vacuum sample chamber and 37 scintillator area detectors. The moderator-to-sample distance is 34.8 m, and the sample-to-detector distance is 800 mm. The wavelength of incident neutrons is 0.4–4.4 Å (first frame). Because short-wavelength neutrons are available and the large solid angle around the sample position is covered by the area detectors, a large reciprocal space can be simultaneously measured. Furthermore, the vacuum sample chamber and collimator have been designed to produce a very low background level. Thus, the measurement of a small single crystal is possible. As sample environment devices, a newly developed cryostat with a two-axis (ω and φ axes) goniometer and some extreme environment devices, e.g. a vertical-field magnet, high-temperature furnace and high-pressure cell, are available. The structure analysis of a sub-millimetre size (0.1 mm3) single organic crystal, taurine, and a magnetic structure analysis of the antiferromagnetic phase of MnF2 have been performed. These results demonstrate that SENJU can be a powerful tool to promote materials science research. PMID:26937237

  5. Identified charged hadron production in pp, p-Pb and Pb-Pb collisions at LHC energies with ALICE

    NASA Astrophysics Data System (ADS)

    Volpe, Giacomo

    2015-05-01

    The ALICE detector is dedicated to the study of strongly interacting matter in the extremely high temperature and energy density conditions reached in relativistic heavy-ions collisions at the LHC. ALICE has unique particle identification (PID) capabilities among the LHC experiments thanks to the use of the combination of different PID techniques, i.e. energy loss and time of flight measurements, Cherenkov and transition radiation detection, calorimetry and topological ID. The latest results on charged pions, kaons and (anti)protons transverse momentum (pT) spectra, ratios and integrated yields, measured in pp collisions at √s = 7 TeV and √s = 2.76 TeV, Pb-Pb collisions at √sNN = 2.76 TeV and p-Pb collisions at √sNN = 5.02 TeV, will be presented. The nuclear modification factors as a function of pT, for Pb-Pb and p-Pb interactions, will be shown. The results from different colliding systems will be compared. These will also be compared with calculations from hydrodynamical and statistical hadronization models.

  6. STiC — a mixed mode silicon photomultiplier readout ASIC for time-of-flight applications

    NASA Astrophysics Data System (ADS)

    Harion, T.; Briggl, K.; Chen, H.; Fischer, P.; Gil, A.; Kiworra, V.; Ritzert, M.; Schultz-Coulon, H.-C.; Shen, W.; Stankova, V.

    2014-02-01

    STiC is an application specific integrated circuit (ASIC) for the readout of silicon photomultipliers. The chip has been designed to provide a very high timing resolution for time-of-flight applications in medical imaging and particle physics. It is dedicated in particular to the EndoToFPET-US project, which is developing an endoscopic PET detector combined with ultrasound imaging for early pancreas and prostate cancer detection. This PET system aims to provide a spatial resolution of 1 mm and a time-of-flight resolution of 200 ps FWHM. The analog frontend of STiC can use either a differential or single ended connection to the SiPM. The time and energy information of the detector signal is encoded into two time stamps. A special linearized time-over-threshold method is used to obtain a linear relation between the signal charge and the measured signal width, improving the energy resolution. The trigger signals are digitized by an integrated TDC module with a resolution of less than 20 ps. The TDC data is stored in an internal memory and transfered over a 160 MBit/s serial link using 8/10 bit encoding. First coincidence measurements using a 3.1 × 3.1 × 15 mm3 LYSO crystal and a S10362-33-50 Hamamtsu MPPC show a coincidence time resolution of less than 285 ps. We present details on the chip design as well as first characterization measurements.

  7. Status of the ALICE experiment at the LHC

    SciTech Connect

    Herrera Corral, G.

    2008-11-13

    The Large Hadron Collider will provide soon, beams of protons and collisions at high energy to the experiments. ALICE stands for A Large Ion Collider Experiment. It is one of the experiments at the Large Hadron Collider. ALICE will be dedicated to the study of heavy ion collisions. The main goal of ALICE is the observation of the transition of ordinary matter into a plasma of quarks and gluons. ALICE consists of 16 systems of detection. Two of them were designed and constructed in Mexico: i) The V0A detector, located at 3.2 mts. from the interaction point and ii) The cosmic ray detector on the top of the magnet. After a quick review of the LHC and the ALICE experiment we will focus on the description of these systems.

  8. The Time of Flight Upgrade for CLAS at 12 GeV

    SciTech Connect

    Graham, Lewis

    2007-10-26

    The Time of Flight (TOF) system is a detection system within the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson National Accelerator Facility. CLAS, being a magnetic toroidal multi-gap spectrometer, is used in the detection of particles and their varying properties. Jefferson National Accelerator Facility is providing an incoming electron beam of energy 6 GeV that is used to probe the structure and production of these particles. The CLAS detector is currently adapted to energies of up to 6 GeV, but with recent approval it will now upgrade to energies of 12 GeV. CLAS consists of drift chambers to determine the charged particle paths, gas Cherenkov counters for electron discrimination, TOF scintillators for particle identification, and an electromagnetic calorimeter for identifying showering electrons and photons. The TOF system, which is our focus, is composed of scintillation counters at the forward angle, and covers an area of 206 meters squared. Therefore, we look to upgrade and construct the TOF system of CLAS and outline strategies of current construction, purpose for design, and outlook for the TOF system upgrade.

  9. Crystal timing offset calibration method for time of flight PET scanners

    NASA Astrophysics Data System (ADS)

    Ye, Jinghan; Song, Xiyun

    2016-03-01

    In time-of-flight (TOF) positron emission tomography (PET), precise calibration of the timing offset of each crystal of a PET scanner is essential. Conventionally this calibration requires a specially designed tool just for this purpose. In this study a method that uses a planar source to measure the crystal timing offsets (CTO) is developed. The method uses list mode acquisitions of a planar source placed at multiple orientations inside the PET scanner field-of-view (FOV). The placement of the planar source in each acquisition is automatically figured out from the measured data, so that a fixture for exactly placing the source is not required. The expected coincidence time difference for each detected list mode event can be found from the planar source placement and the detector geometry. A deviation of the measured time difference from the expected one is due to CTO of the two crystals. The least squared solution of the CTO is found iteratively using the list mode events. The effectiveness of the crystal timing calibration method is evidenced using phantom images generated by placing back each list mode event into the image space with the timing offset applied to each event. The zigzagged outlines of the phantoms in the images become smooth after the crystal timing calibration is applied. In conclusion, a crystal timing calibration method is developed. The method uses multiple list mode acquisitions of a planar source to find the least squared solution of crystal timing offsets.

  10. Novel time-of-flight spectrometer for the analysis of positron annihilation induced Auger electrons

    SciTech Connect

    Hugenschmidt, Christoph; Legl, Stefan

    2006-10-15

    Positron annihilation induced Auger-electron spectroscopy (PAES) has several advantages over conventional Auger-electron spectroscopy such as extremely high surface sensitivity and outstanding signal-to-noise ratio at the Auger-transition energy. In order to benefit from these prominent features a low-energy positron beam of high intensity is required for surface sensitive PAES studies. In addition, an electron energy analyzer is required, which efficiently detects the Auger electrons with acceptable energy resolution. For this reason a novel time-of-flight (TOF) spectrometer has been developed at the intense positron source NEPOMUC that allows PAES studies within short measurement time. This TOF-PAES setup combines a trochoidal filter and a flight tube in a Faraday cage in order to achieve an improved energy resolution of about 1 eV at high electron energies up to E{approx_equal}1000 eV. The electron flight time is the time between the annihilation radiation at the sample and when the electron hits a microchannel plate detector at the end of the flight tube.

  11. The Time of Flight Upgrade for CLAS at 12 GeV

    SciTech Connect

    Lewis Graham

    2007-10-01

    The Time of Flight (TOF) system is a detection system within the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson National Accelerator Facility. CLAS, being a magnetic toroidal multi-gap spectrometer, is used in the detection of particles and their varying properties. Jefferson National Accelerator Facility is providing an incoming electron beam of energy 6 GeV that is used to probe the structure and production of these particles. The CLAS detector is currently adapted to energies of up to 6 GeV, but with recent approval it will now upgrade to energies of 12 GeV. CLAS consists of drift chambers to determine the charged particle paths, gas Cherenkov counters for electron discrimination, TOF scintillators for particle identification, and an electromagnetic calorimeter for identifying showering electrons and photons. The TOF system, which is our focus, is composed of scintillation counters at the forward angle, and covers an area of 206 meters squared. Therefore, we look to upgrade and construct the TOF system of CLAS and outline strategies of current construction, purpose for design, and outlook for the TOF system upgrade

  12. Combining endoscopic ultrasound with Time-Of-Flight PET: The EndoTOFPET-US Project

    NASA Astrophysics Data System (ADS)

    Frisch, Benjamin

    2013-12-01

    The EndoTOFPET-US collaboration develops a multimodal imaging technique for endoscopic exams of the pancreas or the prostate. It combines the benefits of high resolution metabolic imaging with Time-Of-Flight Positron Emission Tomography (TOF PET) and anatomical imaging with ultrasound (US). EndoTOFPET-US consists of a PET head extension for a commercial US endoscope and a PET plate outside the body in coincidence with the head. The high level of miniaturization and integration creates challenges in fields such as scintillating crystals, ultra-fast photo-detection, highly integrated electronics, system integration and image reconstruction. Amongst the developments, fast scintillators as well as fast and compact digital SiPMs with single SPAD readout are used to obtain the best coincidence time resolution (CTR). Highly integrated ASICs and DAQ electronics contribute to the timing performances of EndoTOFPET. In view of the targeted resolution of around 1 mm in the reconstructed image, we present a prototype detector system with a CTR better than 240 ps FWHM. We discuss the challenges in simulating such a system and introduce reconstruction algorithms based on graphics processing units (GPU).

  13. Fast-neutron Induced Reactions at the nELBE Time-of-flight Facility

    NASA Astrophysics Data System (ADS)

    Junghans, A. R.; Beyer, R.; Elekes, Z.; Grosse, E.; Hannaske, R.; Kögler, T.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2014-05-01

    The compact neutron-time-of-flight facility nELBE at the superconducting electron accelerator ELBE of Helmholtz-Zentrum Dresden-Rossendorf is being rebuilt and extended with a low-background experimental hall. The neutron radiator consists of a liquid lead circuit without additional neutron moderators. The useful neutron spectrum extends from some tens of keV to about 10 MeV. nELBE is intended to deliver cross section data of fast-neutron nuclear interactions e.g. for the transmutation of nuclear waste and improvement of neutron physical simulations of innovative nuclear systems. Before the extension of the facility, the photon production cross section of 56Fe was measured with an HPGe detector and the inelastic neutron scattering cross section to the first few excited states in 56Fe was determined. The neutron total cross sections of Au and Ta were determined in the energy from 200 keV to 7 MeV in a transmission experiment.

  14. TOF (time-of-flight) measurements of pulsed neutrons for texture analysis of low symmetry materials

    SciTech Connect

    Larson, A.C.; Vergamini, P.J.; Lujan, M. Jr. ); Wenk, H.R. . Dept. of Geology and Geophysics)

    1989-01-01

    The single crystal diffractometer at LANSCE, SCD, provides and ideal capability for the study of preferred orientation in geological samples by time-of flight (TOF) measurement of pulsed neutrons. The 2-d position sensitive neutron detector with the large wave length range allows one to measure the complete distribution of intensities for several poles very quickly. Each histogram covers about {pi}{sup 2}/16 radians of reciprocal space and contains information from all possible poles visible with the wave length range used, usually about 0.5 to 5.0{Angstrom}. With this method complete pole figures of many lattice planes can be constructed from only 12 to 20 sample orientations as compared to over 1000 sample settings per lattice plane using conventional diffractometers. Pole figures from measurements of experimentally deformed standard samples of calcite and quartzite with known history of deformation provide information about deformation mechanisms and their temperature/strain history. This information can be applied to interpret preferred orientation of naturally deformed rocks. 6 refs., 10 figs.

  15. Time-of-flight mass spectrographs—From ions to neutral atoms

    NASA Astrophysics Data System (ADS)

    Möbius, E.; Galvin, A. B.; Kistler, L. M.; Kucharek, H.; Popecki, M. A.

    2016-12-01

    After their introduction to space physics in the mid 1980s time-of-flight (TOF) spectrographs have become a main staple in spaceborne mass spectrometry. They have largely replaced magnetic spectrometers, except when extremely high mass resolution is required to identify complex molecules, for example, in the vicinity of comets or in planetary atmospheres. In combination with electrostatic analyzers and often solid state detectors, TOF spectrographs have become key instruments to diagnose space plasma velocity distributions, mass, and ionic charge composition. With a variety of implementation schemes that also include isochronous electric field configurations, TOF spectrographs can respond to diverse science requirements. This includes a wide range in mass resolution to allow the separation of medium heavy isotopes or to simply provide distributions of the major species, such as H, He, and O, to obtain information on source tracers or mass fluxes. With a top-hat analyzer at the front end, or in combination with deflectors for three-axis stabilized spacecraft, the distribution function of ions can be obtained with good time resolution. Most recently, the reach of TOF ion mass spectrographs has been extended to include energetic neutral atoms. After selecting the arrival direction with mechanical collimation, followed by conversion to ions, adapted TOF sensors form a new branch of the spectrograph family tree. We review the requirements, challenges, and implementation schemes for ion and neutral atom spectrographs, including potential directions for the future, while largely avoiding overlap with complementary contributions in this special issue.

  16. Neutron time-of-flight spectroscopy measurement using a waveform digitizer

    NASA Astrophysics Data System (ADS)

    Liu, Long-Xiang; Wang, Hong-Wei; Ma, Yu-Gang; Cao, Xi-Guang; Cai, Xiang-Zhou; Chen, Jin-Gen; Zhang, Gui-Lin; Han, Jian-Long; Zhang, Guo-Qiang; Hu, Ji-Feng; Wang, Xiao-He

    2016-05-01

    The photoneutron source (PNS, phase 1), an electron linear accelerator (linac)-based pulsed neutron facility that uses the time-of-flight (TOF) technique, was constructed for the acquisition of nuclear data from the Thorium Molten Salt Reactor (TMSR) at the Shanghai Institute of Applied Physics (SINAP). The neutron detector signal used for TOF calculation, with information on the pulse arrival time, pulse shape, and pulse height, was recorded by using a waveform digitizer (WFD). By using the pulse height and pulse-shape discrimination (PSD) analysis to identify neutrons and γ-rays, the neutron TOF spectrum was obtained by employing a simple electronic design, and a new WFD-based DAQ system was developed and tested in this commissioning experiment. The DAQ system developed is characterized by a very high efficiency with respect to millisecond neutron TOF spectroscopy. Supported by Strategic Priority Research Program of the Chinese Academy of Science(TMSR) (XDA02010100), National Natural Science Foundation of China(NSFC)(11475245,No.11305239), Shanghai Key Laboratory of Particle Physics and Cosmology (11DZ2260700)

  17. Diting: A polarized time-of-flight neutron reflectometer at CMRR reactor in China

    NASA Astrophysics Data System (ADS)

    Li, Xinxi; Huang, Chaoqiang; Wang, Yan; Chen, Bo; Sun, Guang'ai; Liu, Yaoguang; Gong, Jian; Kang, Wu; Liu, Hangang

    2016-11-01

    A new time-of-flight neutron reflectometer with a polarization option is developed and tested at the Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, China. Its scattering geometry is horizontal. The constructed neutron reflectometer is a multipurpose instrument that can be used for the characterization of a stratified microstructure and hidden interfaces of solid thin films. Diting is designed for both magnetic and nonmagnetic multi-layer thin films. Spin polarization and analysis are achieved by transmission magnetized supermirrors. The sample unit is equipped with an electromagnet, which can provide a vertical magnetic field range of 0-1.2 tesla. The available neutron beam is a white beam with wavelength range of 0.15-1.25 nm, which can be cut into different wavelength resolution neutron pulses by a four-disk chopper. A two-dimensional position-sensitive detector is employed to count the specular and off-specular reflected neutron beam. A minimum reflectivity of 10-6 is measured on this instrument.

  18. Novel time-of-flight spectrometer for the analysis of positron annihilation induced Auger electrons

    NASA Astrophysics Data System (ADS)

    Hugenschmidt, Christoph; Legl, Stefan

    2006-10-01

    Positron annihilation induced Auger-electron spectroscopy (PAES) has several advantages over conventional Auger-electron spectroscopy such as extremely high surface sensitivity and outstanding signal-to-noise ratio at the Auger-transition energy. In order to benefit from these prominent features a low-energy positron beam of high intensity is required for surface sensitive PAES studies. In addition, an electron energy analyzer is required, which efficiently detects the Auger electrons with acceptable energy resolution. For this reason a novel time-of-flight (TOF) spectrometer has been developed at the intense positron source NEPOMUC that allows PAES studies within short measurement time. This TOF-PAES setup combines a trochoidal filter and a flight tube in a Faraday cage in order to achieve an improved energy resolution of about 1eV at high electron energies up to E ≈1000eV. The electron flight time is the time between the annihilation radiation at the sample and when the electron hits a microchannel plate detector at the end of the flight tube.

  19. Development and Applications of Time of Flight Neutron Depth Profiling

    SciTech Connect

    Bingham Cady; Kenan Unlu

    2005-03-17

    The depth profiles of intentional or intrinsic constituents of a sample provide valuable information for the characterization of materials. For example, the subtle differences in spatial distribution and composition of many chemical species in the near surface region and across interfacial boundaries can significantly alter the electronic and optical properties of materials. A number of analytical techniques for depth profiling have been developed during the last two decades. neutron Depth Profiling (NDP) is one of the leading analytical techniques. The NDP is a nondestructive near surface technique that utilizes thermal/cold neutron beam to measure the concentration of specific light elements versus their depth in materials. The depth is obtained from the energy loss of protons, alphas or recoil atoms in substrate materials. Since the charged particle energy determination using surface barrier detector is used for NDP, the depth resolution is highly dependent on the detectors an d detection instruments. The depth resolutions of a few tens of nm are achieved with available NDP facilities in the world. However, the performance of NDP needs to be improved in order to obtain a few A depth resolutions.

  20. Research and development on a sub 100 PICO second time-of-flight system based on silicon avalanche diodes

    SciTech Connect

    Choi, Y.; Hirsch, A.; Hauger, A.; Scharenberg, R.; Tincknell, M.; Rai, G.

    1991-12-31

    Particle identification requires a momentum measurement and a second independent determination either energy loss (dE/dx) or time of flight (TOF). To cover a momentum range from 0.1 GeV/c to 1.5 GeV/c in the STAR detector requires both the dE/dx and TOF techniques. This research is designed to develop the avalanche diode (AVD) detectors for TOF systems and evaluate their performance. The test of a small prototype system would be carried out at Purdue and at accelerator test beam sites. The Purdue group has developed a complete test setup for evaluating the time resolution of the AVD`s which includes fast-slow electronic channels, CAMAC based electronic modules and a temperature controlled environment. The AVDs also need to be tested in a 0.5 tesla magnetic field. The Purdue group would augment this test set up to include a magnetic field.

  1. Concept for a time-of-flight Small Angle Neutron Scattering instrument at the European Spallation Source

    NASA Astrophysics Data System (ADS)

    Jaksch, S.; Martin-Rodriguez, D.; Ostermann, A.; Jestin, J.; Duarte Pinto, S.; Bouwman, W. G.; Uher, J.; Engels, R.; Frielinghaus, H.

    2014-10-01

    A new Small Angle Neutron Scattering instrument is proposed for the European Spallation Source. The pulsed source requires a time-of-flight analysis of the gathered neutrons at the detector. The optimal instrument length is found to be rather large, which allows for a polarizer and a versatile collimation. The polarizer allows for studying magnetic samples and incoherent background subtraction. The wide collimation will host VSANS and SESANS options that increase the resolution of the instrument towards μm and tens of μm, respectively. Two 1 m2 area detectors will cover a large solid angle simultaneously. The expected gains for this new instrument will lie in the range between 20 and 36, depending on the assessment criteria, when compared to up-to-date reactor based instruments. This will open new perspectives for fast kinetics, weakly scattering samples, and multi-dimensional contrast variation studies.

  2. Time of Flight Measurements for Neutrons Produced in Reactions Driven by Laser-Target Interactions at Petawatt level

    NASA Astrophysics Data System (ADS)

    Kisyov, S.; Negoita, F.; Gugiu, M. M.; Higginson, D. P.; Vassura, L.; Borghesi, M.; Bernstein, L.; Bleuel, D. L.; Gobet, F.; Goldblum, B. L.; Green, A.; Hannachi, F.; Kar, S.; Petrascu, H.; Pietreanu, D.; Quentin, L.; Schroer, A.-M.; Tarisien, M.; Versteegen, M.; Willi, O.; Antici, P.; Fuchs, J.

    Short intense pulses of fast neutrons were produced in a two stage laser-driven experiment. Protons were accelerated by means of the Target Normal Sheath Acceleration (TNSA) method using the TITAN facility at the Lawrence Livermore National Laboratory. Neutrons were obtained following interactions of the protons with a secondary lithium fluoride (LiF) target. The properties of the neutron flux were studied using BC-400 plastic scintillation detectors and the neutron time of flight (nTOF) technique. The detector setup and the experimental conditions were simulated with the Geant4 toolkit. The effects of different components of the experimental setup on the nTOF were studied. Preliminary results from a comparison between experimental and simulated nTOF distributions are presented.

  3. Development of analytically capable time-of-flight mass spectrometer with continuous ion introduction

    NASA Astrophysics Data System (ADS)

    Hárs, György; Dobos, Gábor

    2010-03-01

    The present article describes the results and findings explored in the course of the development of the analytically capable prototype of continuous time-of-flight (CTOF) mass spectrometer. Currently marketed pulsed TOF (PTOF) instruments use ion introduction with a 10 ns or so pulse width, followed by a waiting period roughly 100 μs. Accordingly, the sample is under excitation in 10-4 part of the total measuring time. This very low duty cycle severely limits the sensitivity of the PTOF method. A possible approach to deal with this problem is to use linear sinusoidal dual modulation technique (CTOF) as described in this article. This way the sensitivity of the method is increased, due to the 50% duty cycle of the excitation. All other types of TOF spectrometer use secondary electron multiplier (SEM) for detection, which unfortunately discriminates in amplification in favor of the lighter ions. This discrimination effect is especially undesirable in a mass spectrometric method, which targets high mass range. In CTOF method, SEM is replaced with Faraday cup detector, thus eliminating the mass discrimination effect. Omitting SEM is made possible by the high ion intensity and the very slow ion detection with some hundred hertz detection bandwidth. The electrometer electronics of the Faraday cup detector operates with amplification 1010 V/A. The primary ion beam is highly monoenergetic due to the construction of the ion gun, which made possible to omit any electrostatic mirror configuration for bunching the ions. The measurement is controlled by a personal computer and the intelligent signal generator Type Tabor WW 2571, which uses the direct digital synthesis technique for making arbitrary wave forms. The data are collected by a Labjack interface board, and the fast Fourier transformation is performed by the software. Noble gas mixture has been used to test the analytical capabilities of the prototype setup. Measurement presented proves the results of the mathematical

  4. A compact Ultra-High Vacuum (UHV) compatible instrument for time of flight-energy measurements of slow heavy reaction products

    NASA Astrophysics Data System (ADS)

    Kuznetsov, A. V.; van Veldhuizen, E. J.; Westerberg, L.; Lyapin, V. G.; Aleklett, K.; Loveland, W.; Bondorf, J.; Jakobsson, B.; Whitlow, H. J.; El Bouanani, M.

    2000-10-01

    A compact Ultra-High Vacuum (UHV) compatible instrument for time of flight-energy measurements of slow heavy reaction products from nuclear reactions has been designed and tested at the CELSIUS storage ring in Uppsala. The construction is based on MicroChannel Plate (MCP) time detectors of the electron mirror type and silicon p-i-n diodes, and permits the detectors to be stacked side-by-side to achieve large solid angle coverage. This kind of telescope measures the Time of Flight (ToF) and Energy (E) of the particle from which one can reconstruct mass. The combination of an ultra-thin cluster gas-jet target and thin carbon emitter foils allows one to measure heavy residues down to an energy of ˜35 keV/nucleon from the interactions of 400 MeV/nucleon 16O with natXe gas targets.

  5. Strangeness detection in ALICE experiment at LHC

    SciTech Connect

    Safarik, K.

    1995-07-15

    The authors present some parameters of the ALICE detector which concern the detection of strange particles. The results of a simulation for neutral strange particles and cascades, together with estimated rates are presented. They also briefly discuss the detection of charged K-mesons. Finally, they mention the possibility of open charm particle detection.

  6. High-performance multiple-reflection time-of-flight mass spectrometers for research with exotic nuclei and for analytical mass spectrometry

    NASA Astrophysics Data System (ADS)

    Plaß, Wolfgang R.; Dickel, Timo; Ayet San Andres, Samuel; Ebert, Jens; Greiner, Florian; Hornung, Christine; Jesch, Christian; Lang, Johannes; Lippert, Wayne; Majoros, Tamas; Short, Devin; Geissel, Hans; Haettner, Emma; Reiter, Moritz P.; Rink, Ann-Kathrin; Scheidenberger, Christoph; Yavor, Mikhail I.

    2015-11-01

    A class of multiple-reflection time-of-flight mass spectrometers (MR-TOF-MSs) has been developed for research with exotic nuclei at present and future accelerator facilities such as GSI and FAIR (Darmstadt), and TRIUMF (Vancouver). They can perform highly accurate mass measurements of exotic nuclei, serve as high-resolution, high-capacity mass separators and be employed as diagnostics devices to monitor the production, separation and manipulation of beams of exotic nuclei. In addition, a mobile high-resolution MR-TOF-MS has been developed for in situ applications in analytical mass spectrometry ranging from environmental research to medicine. Recently, the MR-TOF-MS for GSI and FAIR has been further developed. A novel RF quadrupole-based ion beam switchyard has been developed that allows merging and splitting of ion beams as well as transport of ions into different directions. It efficiently connects a test and reference ion source and an auxiliary detector to the system. Due to an increase in the kinetic energy of the ions in the time-of-flight analyzer of the MR-TOF-MS, a given mass resolving power is now achieved in less than half the time-of-flight. Conversely, depending on the time-of-flight, the mass resolving power has been increased by a factor of more than two.

  7. Applying of the optical time-of-flight spectroscopy for the paper and pulp characterization

    NASA Astrophysics Data System (ADS)

    Pluciński, Jerzy

    2006-02-01

    The paper presents benefits of optical time-of-flight spectroscopy for the pulp and paper characterization. A semiconductor pulse laser and a streak camera as the photodetector were utilized in experimental part of research described in this paper. Distribution of the time of flight of photons through various kinds of wood pulp (e.g. pulp after mechanical treatment coming both fi-om tree species giving hard and soft wood and pulp after thermo-mechanical treatment) was measured. The pulp samples used in the measurements had consistency ranging from 0 to 5% of dry mass in the suspension. The influence of additives (kaolin, talc and calcium carbonate) present in the suspension on the time of flight distribution of photons was studied as well. Finally, dependence of the time of flight of photons through various kinds of the paper (i.e. newspaper, copy paper, and tissue) on the thickness of the sample was investigated.

  8. Equivalent flaw time-of-flight diffraction sizing with ultrasonic phased arrays

    NASA Astrophysics Data System (ADS)

    Engle, Brady J.; Schmerr, Lester W., Jr.; Sedov, Alexander

    2013-01-01

    Ultrasonic phased array transducers can be used to extend traditional time-of-flight diffraction (TOFD) crack sizing, resulting in more quantitative information about the crack being obtained. Traditional TOFD yields a single length parameter, while the equivalent flaw time-of-flight diffraction crack sizing method (EFTOFD) described here uses data from multiple look-angles to fit an equivalent degenerate ellipsoid to the crack. The size and orientation of the equivalent flaw can be used to estimate the actual crack size.

  9. BGO as a hybrid scintillator / Cherenkov radiator for cost-effective time-of-flight PET.

    PubMed

    Brunner, Stefan E; Schaart, Dennis

    2017-03-30

    Due to detector developments in the last decade, the time-of-flight (TOF) method is now commonly used to improve the quality of positron emission tomography (PET) images. Clinical TOF-PET systems based on L(Y)SO:Ce crystals and silicon photomultipliers (SiPMs) with coincidence resolving times (CRT) between 325 ps and 400 ps FWHM have recently been developed. Before the introduction of L(Y)SO:Ce, BGO was used in many PET systems. In addition to a lower price, BGO offers a superior attenuation coefficient and a higher photoelectric fraction than L(Y)SO:Ce. However, BGO is generally considered an inferior TOF-PET scintillator. In recent years, TOF-PET detectors based on the Cherenkov effect have been proposed. However, the low Cherenkov photon yield in the order of ∽10 photons per event complicates energy discrimination-a severe disadvantage in clinical PET. The optical characteristics of BGO, in particular its high transparency down to 310 nm and its high refractive index of ∽2.15, are expected to make it a good Cherenkov radiator. Here, we study the feasibility of combining event timing based on Cherenkov emission with energy discrimination based on scintillation in BGO, as a potential approach towards a cost-effective TOF-PET detector. Rise time measurements were performed using a time-correlated single photon counting (TCSPC) setup implemented on a digital photon counter (DPC) array, revealing a prompt luminescent component likely to be due to Cherenkov emission. Coincidence timing measurements were performed using BGO crystals with a cross-section of 3 mm × 3 mm and five different lengths between 3 mm and 20 mm, coupled to DPC arrays. Non-Gaussian coincidence spectra with a FWHM of 200 ps were obtained with the 27 mm3 BGO cubes, while FWHM values as good as 330 ps were achieved with the 20 mm long crystals. The FWHM value was found to improve with decreasing temperature, while the FWTM value showed the opposite trend.

  10. Time-of-Flight Mass Spectrometry with a Pulsed Glow Discharge Ionization Source.

    PubMed

    Steiner, R E; Lewis, C L; King, F L

    1997-05-01

    The pulsed glow discharge (GD) plasma source exhibits several characteristics that make it ideally suited for use with time-of-flight mass spectrometry (TOFMS). TOFMS uniquely affords the ability to monitor a narrow temporal window for a time-varying process such as ion formation in the pulsed glow discharge plasma. Pulsed GD-TOFMS exhibited distinct advantages for the direct determination of trace elements in solid state samples. Initially, the pulse-powered GD-TOFMS system used for these investigations exhibited poor resolution. In an effort to improve resolution, a slit was introduced to narrow the ion beam orthogonally entering the extraction region of the TOFMS. In an effort to determine optimal operating conditions, the influence of slit width on TOF performance was investigated. In the course of this study, the slit width was found to influence isotope ratio accuracy as well as resolution. A slit width of 1.0 mm was determined to provide the best compromise between resolution and isotope ratio accuracy. Pulsed GD-TOFMS affords improved sensitivity and selectivity because Penning ionization is enhanced during the time period immediately following the termination of the discharge power. Ions sampled by an extraction pulse applied after power termination also yield a mass spectrum that is free of contributions arising from electron-ionized interferences. This advantage arises because only ions generated via the Penning ionization mechanism persist after the termination of discharge power. Sampling in the "afterpeak" time regime eliminates the saturation of the detector arising from discharge support gas ion signal.

  11. CF NEUTRON TIME OF FLIGHT TRANSMISSION FOR MATERIAL IDENTIFICATION FOR WEAPONS TRAINERS

    SciTech Connect

    Mihalczo, John T; Valentine, Timothy E; Blakeman, Edward D; Pare, Victor

    2011-01-01

    The neutron transmission, elastic scattering, and non elastic reactions can be used to distinguish various isotopes. Neutron transmission as a function of energy can be used in some cases to identify materials in unknown objects. A time tagged californium source that provides a fission spectrum of neutrons is a useful source for neutron time-of-flight (TOF) transmission measurements. Many nuclear weapons trainer units for a particular weapons system (no fissile, but of same weight and center of gravity) in shipping containers were returned to the National Nuclear Security Administration Y-12 National Security Complex in the mid 1990s. Nuclear Materials Identification System (NMIS) measurements with a time tagged californium neutron source were used to verify that these trainers did not contain fissile material. In these blind tests, the time distributions of neutrons through the containers were measured as a function of position to locate the approximate center of the trainer in the container. Measurements were also performed with an empty container. TOF template matching measurements were then performed at this location for a large number of units. In these measurements, the californium source was located on one end of the container and a proton recoil scintillator was located on the other end. The variations in the TOF transmission for times corresponding to 1 to 5 MeV were significantly larger than statistical. Further examination of the time distribution or the energy dependence revealed that these variations corresponded to the variations in the neutron cross section of aluminum averaged over the energy resolution of the californium TOF measurement with a flight path of about 90 cm. Measurements using different thicknesses of aluminum were also performed with the source and detector separated the same distance as for the trainer measurements. These comparison measurements confirmed that the material in the trainers was aluminum, and the total thickness of

  12. ALICE moves into warp drive

    NASA Astrophysics Data System (ADS)

    Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F.; Dénes, E.; Divià, R.; Fuchs, U.; Grigore, A.; Simonetti, G.; Soós, C.; Telesca, A.; Vande Vyvre, P.; von Haller, B.

    2012-12-01

    A Large Ion Collider Experiment (ALICE) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Since its successful start-up in 2010, the LHC has been performing outstandingly, providing to the experiments long periods of stable collisions and an integrated luminosity that greatly exceeds the planned targets. To fully explore these privileged conditions, we aim at maximizing the experiment's data taking productivity during stable collisions. We present in this paper the evolution of the online systems towards helping us understand reasons of inefficiency and address new requirements. This paper describes the features added to the ALICE Electronic Logbook (eLogbook) to allow the Run Coordination team to identify, prioritize, fix and follow causes of inefficiency in the experiment. Thorough monitoring of the data taking efficiency provides reports for the collaboration to portray its evolution and evaluate the measures (fixes and new features) taken to increase it. In particular, the eLogbook helps decision making by providing quantitative input, which can be used to better balance risks of changes in the production environment against potential gains in quantity and quality of physics data. It will also present the evolution of the Experiment Control System (ECS) to allow on-the-fly error recovery actions of the detector apparatus while limiting as much as possible the loss of integrated luminosity. The paper will conclude with a review of the ALICE efficiency so far and the future plans to improve its monitoring.

  13. New Fast Interaction Trigger for ALICE

    NASA Astrophysics Data System (ADS)

    Trzaska, Wladyslaw Henryk

    2017-02-01

    The LHC heavy-ion luminosity and collision rate from 2021 onwards will considerably exceed the design parameters of the present ALICE forward trigger detectors and the introduction of the Muon Forward Tracker (MFT) will significantly reduce the space available for the new trigger detectors. To comply with these conditions a new Fast Interaction Trigger (FIT) will be built. FIT will be the main forward trigger, luminometer, and interaction-time detector. It will also determine multiplicity, centrality, and reaction plane of heavy-ion collisions. FIT will consist of two arrays of Cherenkov quartz radiators with MCP-PMT sensors and of a plastic scintillator ring. By increasing the overall acceptance of FIT, the scintillator will improve centrality and event plane resolution. It will also add sensitivity for the detection of beam-gas events and provide some degree of redundancy. FIT is currently undergoing an intense R&D and prototyping period. It is scheduled for installation in ALICE during 2020.

  14. Simulations for a Multi-Reflection Time-of-Flight Mass Spectrometer at the University of Notre Dame

    NASA Astrophysics Data System (ADS)

    Kelly, James M.; Nicoloff, Catherine; Schultz, Bradley E.; Brodeur, Maxime

    2016-09-01

    A multi-reflection time-of-flight mass spectrometer (MR-ToF) has been built at the University of Notre Dame. The MR-ToF will provide isobarically pure ion bunches to experiments at Argonne National Laboratory's (ANL) future ``N = 126 Factory'', a unique facility capable of producing very neutron-rich nuclei around the N = 126 shell closure. Prior to its installation at ANL, the MR-ToF is being evaluated in an off-line test setup consisting of a surface ion source, a Bradbury-Nielsen Gate (BNG) to chop the beam before injection into the MR-ToF, and a micro-channel plate detector to record the resulting bunches. The series of simulations investigating the feasibility of this bunching method, as well as the injection of these bunches into the MR-ToF, will be presented. This work is supported by the National Science Foundation.

  15. Second generation fusion neutron time-of-flight spectrometer at optimized rate for fully digital data acquisition

    SciTech Connect

    Zhang, X. E-mail: jnke1@icloud.com Fan, T.; Yuan, X.; Xie, X.; Chen, Z.; Källne, J.; Gorini, G.; Nocente, M.

    2014-04-15

    The progress on high-rate event recording of data is taken as starting point to revisit the design of fusion neutron spectrometers based on the TOF (time-of-flight) technique. The study performed was aimed at how such instruments for optimized rate (TOFOR) can be further developed to enhance the plasma diagnostic capabilities based on measurement of the 2.5 MeV dd neutron emission from D plasmas, especially the weak spectral components that depend on discrimination of extraneous events. This paper describes a design (TOFOR II) adapted for use with digital wave form recording of all detector pulses providing information on both amplitude (pulse height) and timing. The results of simulations are presented and the performance enhancement is assessed in comparison to the present.

  16. Time of flight and the MUSE experiment in the PIM1 Channel at the Paul Sherrer Institute

    NASA Astrophysics Data System (ADS)

    Lin, Wan; MUSE Collaboration

    2015-10-01

    The MUSE experiment in the PIM1 Channel at the Paul Sherrer Institute in Villigen, Switzerland, measures scattering of electrons and muons from a liquid hydrogen target. The intent of the experiment is to deduce from the scattering probabilities whether the radius of the proton is the same when determined from the scattering of the two different particle types. An important technique for the experiment is precise timing measurements, using high precision scintillators and a beam Cerenkov counter. We will describe the motivations for the precise timing measurement. We will present results for the timing measurements from prototype experimental detectors. We will also present results from a simulation program, Geant4, that was used to calculate energy loss corrections to the time of flight determined between the beam Cherenkov counter and the scintillator. This work is supported in part by the U.S. National Science Foundation Grant PHY 1306126 and the Douglass Project for Women in Math, Science, and Engineering.

  17. Current status of a time-of-flight single crystal neutron diffractometer SENJU at J-PARC

    NASA Astrophysics Data System (ADS)

    Tamura, I.; Oikawa, K.; Kawasaki, T.; Ohhara, T.; Kaneko, K.; Kiyanagi, R.; Kimura, H.; Takahashi, M.; Kiyotani, T.; Arai, M.; Noda, Y.; Ohshima, K.

    2012-02-01

    SENJU is a state-of-the-art single crystal time-of-flight Laue diffractometer in Materials and Life Science Experimental Facility at Japan Proton Accelerator Research Complex (J-PARC). The diffractometer is designed for precise crystal and magnetic structure analyses under multiple extreme conditions, such as low temperature, high-pressure, high-magnetic field. Measurements using small sample less than 1.0 mm3 will be also realized, which allows us to study wide variety of materials. SENJU is using a poisoned decoupled moderator to obtain peak profiles of Bragg reflection, and intensity distributions of superlattice reflections and diffuse scatterings with good accuracy. At the beginning, the diffractometer will have 31 two-dimensional scintillator detectors to cover wide area of reciprocal lattice space by a single measurement. The instrument is currently under construction and is scheduled to start on-beam commissioning in February 2012.

  18. Automatic layout of integrated-optic time-of-flight circuits

    NASA Astrophysics Data System (ADS)

    Fogg, Ruth D.

    1996-11-01

    This work describes the architecture and algorithms used in the computer-aided design tool developed for the automatic layout of integrated-optic, time-of-flight circuit designs. As in VLSI circuit layout, total wire length and chip area minimization are the goals in the layout of time-of-flight circuits. However, there are two major differences between the layout of time of flight circuits and VLSI circuits. First, the interconnection lengths of time-of-flight designs are exactly specified in order to achieve the necessary delays for signal synchronization. SEcondly, the switching elements are 120 times longer than they are wide. This highly astigmatic aspect ratio causes severe constraints on how and where the switches are placed. Assuming the continued development of corner turning mirrors allows the use of a parallel, row-based device placement architecture and a rectangular, fixed-grid track system for the connecting paths. The layout process proceeds in two steps. The first step involves the use of a partial circuit graph representation to place the elements in rows, oriented in the direction of the signal flow. After iterative improvement of the placement, the second step proceeds with the routing of the connecting paths. The main problem in the automatic layout of time-of-flight circuits is achieving the correct path lengths without overlapping previously routed paths. This problem is solved by taking advantage of a certain degree of variability present in each path, allowing the use of simple heuristics to circumvent previously routed paths.

  19. Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET.

    PubMed

    Jacobsen, A S; Salewski, M; Eriksson, J; Ericsson, G; Hjalmarsson, A; Korsholm, S B; Leipold, F; Nielsen, S K; Rasmussen, J; Stejner, M

    2014-11-01

    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR.

  20. Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

    SciTech Connect

    Jacobsen, A. S. Salewski, M.; Korsholm, S. B.; Leipold, F.; Nielsen, S. K.; Rasmussen, J.; Stejner, M.; Eriksson, J.; Ericsson, G.; Hjalmarsson, A.

    2014-11-15

    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR.

  1. The ROTAX/DIFF time-of-flight diffractometer at ISIS

    NASA Astrophysics Data System (ADS)

    Tietze-Jaensch, H.; Kockelmann, W.; Schmidt, W.; Will, G.

    1997-02-01

    We report on the setup of the ROTAX instrument as a conventional angle-dispersive time-of-flight diffractometer. This utilisation of the instrument not only provides a powerful and very versatile tool for many bread-and-butter applications in crystallographic and magnetic structure determination but also exploits the methods of single-crystal diffraction of quasi-Laue and diffuse scattering. White beam neutron time-of-flight diffraction expands to a very economic way of obtaining pole figures for texture analysis in bulk-material and earth sciences. Generally speaking, an overall gain-factor of 5-10 is practically achieved compared to an equivalent constant wavelength instrument.

  2. Single-photon pulsed-light indirect time-of-flight 3D ranging.

    PubMed

    Bellisai, S; Bronzi, D; Villa, F A; Tisa, S; Tosi, A; Zappa, F

    2013-02-25

    "Indirect" time-of-flight is one technique to obtain depth-resolved images through active illumination that is becoming more popular in the recent years. Several methods and light timing patterns are used nowadays, aimed at improving measurement precision with smarter algorithms, while using less and less light power. Purpose of this work is to present an indirect time-of-flight imaging camera based on pulsed-light active illumination and a 32 × 32 single-photon avalanche diode array with an improved illumination timing pattern, able to increase depth resolution and to reach single-photon level sensitivity.

  3. Results from (anti-)(hyper-)nuclei production and searches for exotic bound states with ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Sharma, Natasha

    2016-12-01

    The excellent particle identification capabilities of the ALICE detector, using the time projection chamber and the time-of-flight detector, allow the detection of light nuclei and anti-nuclei. Furthermore, the high tracking resolution provided by the inner tracking system enables the separation of primary nuclei from those coming from the decay of heavier systems. This allows for the reconstruction of decays such as the hypertriton mesonic weak decay (H3Λ →3He +π-), the decay of a hypothetical bound state of a Λn into a deuteron and pion or the H-dibaryon decaying into a Λ, a proton and a π-. An overview of the production of stable nuclei and anti-nuclei in proton-proton, proton-lead and, in particular, lead-lead collisions is presented. Hypernuclei production rates in Pb-Pb are also shown, together with the upper limits estimated on the production of hypothetical exotica candidates. The results are compared with predictions for the production in thermal (statistical) and coalescence models.

  4. Alice Occultation - Gladstone

    NASA Video Gallery

    This animation shows how the count rate observed by New Horizons’ Alice instrument decreases as Pluto’s atmosphere passes in front of the sun. The decreasing count rate is due to the ultraviolet s...

  5. Direct time-of-flight for quantitative, real-time in-beam PET: a concept and feasibility study.

    PubMed

    Crespo, Paulo; Shakirin, Georgy; Fiedler, Fine; Enghardt, Wolfgang; Wagner, Andreas

    2007-12-07

    We extrapolate the impact of recent detector and scintillator developments, enabling sub-nanosecond coincidence timing resolution (tau), onto in-beam positron emission tomography (in-beam PET) for monitoring charged-hadron radiation therapy. For tau < or = 200 ps full width at half maximum, the information given by the time-of-flight (TOF) difference between the two opposing gamma-rays enables shift-variant, artefact-free in-beam tomographic imaging by means of limited-angle, dual-head detectors. We present the corresponding fast, TOF-based and backprojection-free, 3D reconstruction algorithm that, coupled with a real-time data acquisition and a fast detector encoding scheme, allows the sampled beta+-activity to be visualized in the object during the course of the irradiation. Despite the very low statistics scenario typical of in-beam PET, real-treatment simulations show that in-beam TOF-PET enables high-precision images to be obtained in real-time, either with closed-ring or with fixed, dual-head in-beam TOF-PET systems. The latter greatly alleviates the installation of in-beam PET at radiotherapeutic sites.

  6. A multichannel time-of-flight system for observation of energetic ions of multispecies generated from relativistic laser plasma

    SciTech Connect

    Matsukado, K.; Fujimoto, M.; Takahashi, H.; Kawada, Y.; Ohsuka, S.; Aoshima, S.

    2010-02-15

    A multichannel time-of-flight (TOF) system was constructed to observe the ions generated from relativistic laser plasma, where the ions have polychromatic energies and multiple species. The TOF system is composed of a ten-channel scintillation detector array and an electromagnet that generates a magnetic field of 0-1.24 T. The magnet field enables us to analyze protons, deuterons, and full-stripped carbon ions to 50, 25, and 150 MeV, respectively. The system experimentally identified protons of 0.27-1.6 MeV energy and ions of a half specific charge (deuterons of 0.3-0.8 MeV and full-stripped carbons of 1.8-4.8 MeV). The measured TOF values agree well with the calculated values within the designed accuracy; {+-}2.5 ns for protons and {+-}5 ns for the others (d or C{sup 6+}) on each detector channel. Comparison of ion numbers detected by a track detector (CR-39) and the TOF system enabled us to obtain the number of ions detected on each scintillation counter with less than 16% error.

  7. Optimizing light transport in scintillation crystals for time-of-flight PET: an experimental and optical Monte Carlo simulation study.

    PubMed

    Berg, Eric; Roncali, Emilie; Cherry, Simon R

    2015-06-01

    Achieving excellent timing resolution in gamma ray detectors is crucial in several applications such as medical imaging with time-of-flight positron emission tomography (TOF-PET). Although many factors impact the overall system timing resolution, the statistical nature of scintillation light, including photon production and transport in the crystal to the photodetector, is typically the limiting factor for modern scintillation detectors. In this study, we investigated the impact of surface treatment, in particular, roughening select areas of otherwise polished crystals, on light transport and timing resolution. A custom Monte Carlo photon tracking tool was used to gain insight into changes in light collection and timing resolution that were observed experimentally: select roughening configurations increased the light collection up to 25% and improved timing resolution by 15% compared to crystals with all polished surfaces. Simulations showed that partial surface roughening caused a greater number of photons to be reflected towards the photodetector and increased the initial rate of photoelectron production. This study provides a simple method to improve timing resolution and light collection in scintillator-based gamma ray detectors, a topic of high importance in the field of TOF-PET. Additionally, we demonstrated utility of our Monte Carlo simulation tool to accurately predict the effect of altering crystal surfaces on light collection and timing resolution.

  8. Dolly and Alice.

    PubMed

    Burk, Dan L

    2015-11-01

    The opinion of the United States Court of Appeals for the Federal Circuit, In re Roslin Institute, rejecting patent claims to mammals cloned from somatic cells, was rendered about a month before the United States Supreme Court's decision in Alice Corp. v. CLS Bank International. The Alice opinion explicitly sets out the standard for determining whether an invention falls within statutory patentable subject matter. Thus one is thus left to wonder what the Roslin opinion might have looked like had it been decided only a few weeks later, after the Alice decision was published, with the benefit of the Supreme Court's further direction on patentable subject matter. In this essay I explore whether in hindsight the Alice standard might have dictated a different outcome in Roslin, suggesting how the two-part test articulated by the Supreme Court in Alice might apply to a 'products of nature' analysis for cloned mammals. Drawing on that analysis, I then use the Roslin case as a vehicle to highlight certain issues with the Supreme Court's current subject matter jurisprudence as applied to biotechnology. By juxtaposing Dolly with Alice, it becomes clear that the Supreme Court has revivified a number of dormant biotechnology patent problems in the guise of subject matter analysis.

  9. Dolly and Alice

    PubMed Central

    Burk, Dan L.

    2015-01-01

    The opinion of the United States Court of Appeals for the Federal Circuit, In re Roslin Institute, rejecting patent claims to mammals cloned from somatic cells, was rendered about a month before the United States Supreme Court's decision in Alice Corp. v. CLS Bank International. The Alice opinion explicitly sets out the standard for determining whether an invention falls within statutory patentable subject matter. Thus one is thus left to wonder what the Roslin opinion might have looked like had it been decided only a few weeks later, after the Alice decision was published, with the benefit of the Supreme Court's further direction on patentable subject matter. In this essay I explore whether in hindsight the Alice standard might have dictated a different outcome in Roslin, suggesting how the two-part test articulated by the Supreme Court in Alice might apply to a ‘products of nature’ analysis for cloned mammals. Drawing on that analysis, I then use the Roslin case as a vehicle to highlight certain issues with the Supreme Court's current subject matter jurisprudence as applied to biotechnology. By juxtaposing Dolly with Alice, it becomes clear that the Supreme Court has revivified a number of dormant biotechnology patent problems in the guise of subject matter analysis. PMID:27774214

  10. Depth profiling of boron in ultra-shallow junction devices using time-of-flight neutron depth profiling (TOF-NDP)

    NASA Astrophysics Data System (ADS)

    Çetiner, Sacit M.; Ünlü, Kenan

    2007-08-01

    In conventional neutron depth profiling (NDP), residual energies of particles are measured directly by using a semiconductor detector. The measured depth resolution is a function of the material composition as well as a function of the energy resolution of the detector and precision of the measurement electronics. The uncertainty from the substrate is inevitable. However, for relatively thin layers, the predominant uncertainty factor in depth resolution is the metallic layer in front of the semiconductor-charged particle detector. The effect of the layer introduces additional straggling to the particle. Time-of-flight neutron depth profiling (TOF-NDP) is presented to eliminate the need to use semiconductor detectors. Particle energy can be determined from the particle arrival time. Energy resolution improvement achieved with TOF-NDP makes it possible to obtain concentration vs. depth profile of boron in ultra-shallow junction devices.

  11. How Constant Momentum Acceleration Decouples Energy and Space Focusing in Distance-of-Flight and Time-of-Flight Mass Spectrometries

    SciTech Connect

    Dennis, Elise; Gundlach-Graham, Alexander W.; Enke, Chris; Ray, Steven J.; Carado, Anthony J.; Barinaga, Charles J.; Koppenaal, David W.; Hieftje, Gary M.

    2013-05-01

    Time-of-flight (TOF) and distance-of-flight (DOF) mass spectrometers require means for focusing ions at the detector(s) because of initial dispersions of position and energy at the time of their acceleration. Time-of-flight mass spectrometers ordinarily employ constant energy acceleration (CEA), which creates a space-focus plane at which the initial spatial dispersion is corrected. In contrast, constant-momentum acceleration (CMA), in conjunction with an ion mirror, provides focus of the initial energy dispersion at the energy focus time for ions of all m/z at their respective positions along the flight path. With CEA, the initial energy dispersion is not simultaneously correctable as its effect on ion velocity is convoluted with that of the spatial dispersion. The initial spatial dispersion with CMA remains unchanged throughout the field-free region of the flight path, so spatial dispersion can be reduced before acceleration. Improved focus is possible when each dispersion can be addressed independently. With minor modification, a TOF mass spectrometer can be operated in CMA mode by treating the TOF detector as though it were a single element in the array of detectors that would be used in a DOF mass spectrometer. Significant improvement in mass resolution is thereby achieved, albeit over a narrow range of m/z values. In this paper, experimental and theoretical results are presented that illustrate the energy-focusing capabilities of both DOF and TOF mass spectrometry.

  12. Sensitivity Upgrades to the Idaho Accelerator Center Neutron Time of Flight Spectrometer

    SciTech Connect

    Thompson, S. J.; Kinlaw, M. T.; Harmon, J. F.; Wells, D. P.; Hunt, A. W.

    2007-10-26

    Past experiments have shown that discrimination between between fissionable and non-fissionable materials is possible using an interrogation technique that monitors for high energy prompt fission neutrons. Several recent upgrades have been made to the neutron time of flight spectrometer at the Idaho Accelerator Center with the intent of increasing neutron detection sensitivity, allowing for system use in nonproliferation and security applications.

  13. Estimating time and time-lag in time-of-flight velocimetry

    NASA Technical Reports Server (NTRS)

    Lading, L.

    1983-01-01

    Estimating time and time-lag in time-of-flight velocimeters is investigated. Statistics of a filtered Poisson point process is given. A Maximum Likelihood Estimator is compared with suboptimum estimators in terms of robustness. For a dominating background combined spatial and temporal processing can improve the robustness compared with purely temporal processing. Schemes for the spatial filters are given.

  14. Time-of-Flight Experiments in Molecular Motion and Electron-Atom Collision Kinematics

    ERIC Educational Resources Information Center

    Donnelly, Denis P.; And Others

    1971-01-01

    Describes a set of experiments for an undergraduate laboratory which demonstrates the relationship between velocity, mass, and temperature in a gas. The experimental method involves time-of-flight measurements on atoms excited to metastable states by electron impact. Effects resulting from recoil in the electron-atom collision can also be…

  15. Characterization of nanoparticles by matrix assisted laser desorption ionization time-of-flight mass spectrometry.

    PubMed

    Ramalinga, Uma; Clogston, Jeffrey D; Patri, Anil K; Simpson, John T

    2011-01-01

    Determining the molecular weight of nanoparticles can be challenging. The molecular weight characterization of dendrimers, for example, with varying covalent and noncovalent modifications is critical to their use as therapeutics. As such, we describe in this chapter a protocol for the analysis of these molecules by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS).

  16. Multiple wavelength time-of-flight sensor based on time-correlated single-photon counting

    NASA Astrophysics Data System (ADS)

    Buller, Gerald S.; Harkins, Ross D.; McCarthy, Aongus; Hiskett, Philip A.; MacKinnon, Gordon R.; Smith, George R.; Sung, Raymond; Wallace, Andrew M.; Lamb, Robert A.; Ridley, Kevin D.; Rarity, John G.

    2005-08-01

    This article describes a time-of-flight sensor based on multiple pulsed laser sources which utilizes time-correlated single-photon counting. The sensor has demonstrated good performance at ranges of up to 17 km in daylight conditions. Analysis techniques were developed to examine the returns from targets containing more than one scattering surface.

  17. Four-Spot Time-Of-Flight Laser Anemometer For Turbomachinery

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.; Skoch, Gary J.

    1995-01-01

    Two-color, four-spot time-of-flight laser anemometer designed for measuring flow velocity within narrow confines of small centrifugal compressor. Apparatus well suited for measuring fast (typical speeds 160 to 700 m/s), highly turbulent gas flows in turbomachinery. Other potential applications include measurement of gas flows in pipelines and in flows from explosions.

  18. The time-of-flight system on the Goddard medium energy gamma-ray telescope

    NASA Technical Reports Server (NTRS)

    Ross, R. W.; Chesney, J. R.

    1979-01-01

    A scintillation counter time of flight system, incorporated into the Goddard 50 cm by 50 cm spark chamber gamma ray telescope is described. The system, which utilizes constant fractions timing and particle position compensation and digitizes up to 10 ns time differences to six bit accuracy in less than 500 ns is analyzed. The performance of this system during balloon flight is discussed.

  19. Identification of Bacteria Using Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry

    ERIC Educational Resources Information Center

    Kedney, Mollie G.; Strunk, Kevin B.; Giaquinto, Lisa M.; Wagner, Jennifer A.; Pollack, Sidney; Patton, Walter A.

    2007-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS or simply MALDI) has become ubiquitous in the identification and analysis of biomacromolecules. As a technique that allows for the molecular weight determination of otherwise nonvolatile molecules, MALDI has had a profound impact in the molecular…

  20. Laser desorption time-of-flight mass spectrometer DNA analyzer. Final report

    SciTech Connect

    Chen, C.H.W.; Martin, S.A.

    1997-02-01

    The objective of this project is the development of a laser desorption time-of-flight mass spectrometer DNA analyzer which can be broadly used for biomedical research. Tasks include: pulsed ion extraction to improve resolution; two-component matrices to enhance ionization; and solid phase DNA purification.

  1. Time-of-Flight Measurement of the Speed of Sound in a Metal Bar

    ERIC Educational Resources Information Center

    Ganci, Salvatore

    2016-01-01

    A simple setup was designed for a "time-of-flight" measurement of the sound speed in a metal bar. The experiment requires low cost components and is very simple to understand by students. A good use of it is as a demonstration experiment.

  2. Proceedings of the 1986 workshop on advanced time-of-flight neutron powder diffraction

    SciTech Connect

    Lawson, A.C.; Smith, K.

    1986-09-01

    This report contains abstracts of talks and summaries of discussions from a small workshop held to discuss the future of time-of-flight neutron powder diffraction and its implementation at the Los Alamos Neutron Scattering Center. 47 refs., 3 figs.

  3. Time-of-Flight Measurement of the Speed of Sound in Water

    ERIC Educational Resources Information Center

    Ganci, Salvatore

    2016-01-01

    A simple setup is designed to investigate a "time-of-flight" measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

  4. Time-of-flight system for a CTOF prototype counter with fine-mesh and standard photomultipliers

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Viacheslav; Chebotarev, Sergey; Dho, Hoseog; Jang, Jonghyuk; Kim, Andrey; Kim, Wooyoung; Milman, Evgeniy; Ni, Andrey

    2012-02-01

    The upgrade of Continuous Electron Beam Accelerator Facility (CEBAF) is undergo since 2010. The updated CEBAF Large Acceptance Spectrometer (CLAS12) detector is being developed for the JLab upgrade program up to 12 GeV. One of the important component of CLAS12 will be the central time-of-flight system (CTOF). The CTOF will provide detection and identification of charged particles emitted at central angles from 40° to 130°. The design goal is to achieve a time-of-flight resolution σ TOF = 50 ps. This study evaluated the timing properties of the CTOF prototype counter. The performance of the upgraded prototype 3 × 3.2 × 66 cm3 scintillation bar of BC-408, coupled to fine-mesh R5924-70 and R7761-70 Hamamatsu photomultipliers via acrylic light guides, has been measured by using two different methods: cosmic rays at Kyungpook National University (KNU), and proton beams at the MC-50 cyclotron of the Korea Institute of Radiological & Medical Sciences (KIRAMS). The gain and the timing resolution of fine-mesh PMs were compared with a conventional Hamamatsu R2083 PM. In the cosmic-ray test, the TOF resolutions were measured to be σ FM-PM = 79 ± 0.75 stat ± 4 syst ps and σ R2083 = 73 ± 1.3 stat ± 4 syst ps for fine-mesh and ordinary photomultipliers, respectively. With proton beams, these values were σ FM-PM = 39.1 ± 0.55 ps and σ R2083 = 35.0 ± 0.54 ps at count rate 0.15 MHz. These remained constant at higher count rates up to 1.5 MHz. The average ratio of the fine-mesh to the ordinary PM resolutions was 1.123 ± 0.02.

  5. Automatic layout of integrated-optics time-of-flight circuits

    NASA Astrophysics Data System (ADS)

    Kennett-Fogg, Ruth D.

    1995-04-01

    This work describes the architecture and algorithms used in the computer aided design tool developed for the automatic layout of integrated optic, time of flight circuit designs. This is similar to the layout of electronic VLSI circuits, where total wire length and chip area minimization are the major goals. Likewise, total wire length and chip area minimization are also the goals in the layout of time of flight circuits. However, there are two major differences between the layout of time of flight circuits and VLSI circuits. First, the interconnection lengths of time of flight designs are exactly specified in order to achieve the necessary delays for signal synchronization. Secondly, the switching elements are 120 times longer than they are wide. This highly astigmatic aspect ratio causes severe constraints on how and where the switches are placed. The assumed development of integrated corner turning mirrors allows the use of a parallel, row based device placement architecture and a rectangular, fixed grid track system for the connecting paths. The layout process proceeds in two steps. The first step involves the use of a partial circuit graph representation to place the elements in rows, oriented in the direction of the signal flow. After iterative improvement of the placement, the second step proceeds with the routing of the connecting paths. The main problem in the automatic layout of time of flight circuits is achieving the correct path lengths without overlapping previously routed paths. This problem is solved by taking advantage of a certain degree of variability present in each path, allowing the use of simple heuristics to circumvent previously routed paths.

  6. Evaluation of the Laser Ablation of Transition Metals/Metal Compounds by Time-of-Flight and Optical Spectroscopy

    DTIC Science & Technology

    1993-01-01

    METAL COMPOUNDS BY TIME- OF -FLIGHT AND OPTICAL SPECTROSCOPY Terry L. Thiem, Lyn R. Watson, James A. Gardner, Rainer A. Dressier, Richard H. Salter and...AD-A267 275 77:.>- June 30, 1993 Reprint Evaluation of tie Laser Ablation of Transition Metals/ Metal Compounds by Time- of -Flight and Optical ...are generated as measured using time- of -flight spectroscopy . The energy range can be controlled with the laser power, similar to studies conducted on

  7. Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectra of poly(butylene adipate).

    PubMed

    Rizzarelli, Paola; Puglisi, Concetto; Montaudo, Giorgio

    2006-01-01

    Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS/MS) was employed to analyze four poly(butylene adipate) (PBAd) oligomers and to investigate their fragmentation pathways as a continuation of our work on the MALDI-TOF/TOF-MS/MS study of synthetic polymers. MALDI-TOF/TOF-MS/MS analysis was performed on oligomers terminated by carboxyl and hydroxyl groups, methyl adipate and hydroxyl groups, dihydroxyl groups, and dicarboxyl groups. The sodium adducts of these oligomers were selected as precursor ions. Different end groups do not influence the fragmentation of sodiated polyester oligomers and similar series of product ions were observed in all the MALDI-TOF/TOF-MS/MS spectra. According to the structures of the most abundant product ions identified in the present work, three fragmentation pathways have been proposed to occur most frequently in PBAd: beta-hydrogen-transfer rearrangement, leading to the selective cleavage of the --O--CH(2)-- bonds; --CH(2)--CH(2)-- (beta--beta) bond cleavage in the adipate moiety; and ester bond scission.

  8. LGB neutron detector

    NASA Astrophysics Data System (ADS)

    Quist, Nicole

    2012-10-01

    The double pulse signature of the Gadolinium Lithium Borate Cerium doped plastic detector suggests its effectiveness for analyzing neutrons while providing gamma ray insensitivity. To better understand this detector, a californium gamma/neutron time of flight facility was constructed in our lab. Reported here are efforts to understand the properties and applications of the LGB detector with regards to neutron spectroscopy.

  9. Measuring time of flight of fusion products in an inertial electrostatic confinement fusion device for spatial profiling of fusion reactions

    SciTech Connect

    Donovan, D. C.; Boris, D. R.; Kulcinski, G. L.; Santarius, J. F.; Piefer, G. R.

    2013-03-15

    A new diagnostic has been developed that uses the time of flight (TOF) of the products from a nuclear fusion reaction to determine the location where the fusion reaction occurred. The TOF diagnostic uses charged particle detectors on opposing sides of the inertial electrostatic confinement (IEC) device that are coupled to high resolution timing electronics to measure the spatial profile of fusion reactions occurring between the two charged particle detectors. This diagnostic was constructed and tested by the University of Wisconsin-Madison Inertial Electrostatic Confinement Fusion Group in the IEC device, HOMER, which accelerates deuterium ions to fusion relevant energies in a high voltage ({approx}100 kV), spherically symmetric, electrostatic potential well [J. F. Santarius, G. L. Kulcinski, R. P. Ashley, D. R. Boris, B. B. Cipiti, S. K. Murali, G. R. Piefer, R. F. Radel, T. E. Radel, and A. L. Wehmeyer, Fusion Sci. Technol. 47, 1238 (2005)]. The TOF diagnostic detects the products of D(d,p)T reactions and determines where along a chord through the device the fusion event occurred. The diagnostic is also capable of using charged particle spectroscopy to determine the Doppler shift imparted to the fusion products by the center of mass energy of the fusion reactants. The TOF diagnostic is thus able to collect spatial profiles of the fusion reaction density along a chord through the device, coupled with the center of mass energy of the reactions occurring at each location. This provides levels of diagnostic detail never before achieved on an IEC device.

  10. Towards arrays of smart-pixels for time-correlated single photon counting and time of flight application

    NASA Astrophysics Data System (ADS)

    Markovic, Bojan; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2011-01-01

    We present a novel "smart-pixel" able to detect single photons and to measure and record in-pixel the time delay between a START pulse (e.g., laser excitation, cell stimulus, or LIDAR flash) and a STOP pulse given by the detection of a single photon (e. g., fluorescence decay signal or back reflection from an object). This smart-pixel represents the basic building block of SPAD arrays aimed at time-correlated single photon counting (TCSPC) applications (like FLIM, FCS, FRET), but also at photon timing and direct Time-of-Flight (dTOF) measurements for 3D ranging applications (e.g., in LIDAR systems). The pixel comprises a Single-Photon Avalanche Diode (SPAD) detector, an analog sensing and driving electronics, and a Time-to-Digital Converter monolithically designed and manufactured into the same chip. We report on the design and characterization of prototype circuits, fabricated in a 0.35 μm standard CMOS technology containing complete conversion channels, smart-pixels and ancillary electronics with 20 μm active area diameter SPAD detectors and related quenching circuitry. With a 100 MHz reference clock, the TDC provides a time-resolution of 10 ps, a dynamic range of 160 ns and very high conversion linearity.

  11. Analysis of low molecular weight acids by negative mode matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    PubMed

    Shroff, Rohit; Muck, Alexander; Svatos, Ales

    2007-01-01

    Free 9-aminoacridine base is demonstrated to be a suitable matrix for negative mode matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOFMS) analysis of a wide range of low molecular weight organic acids including aliphatic (from acetic to palmitic acid), aromatic acids, phytohormones (e.g. jasmonic and salicylic acids), and amino acids. Low limits of quantitation in the femtomolar range (jasmonic - 250 fmol; caffeic - 160 fmol and salicylic - 12.5 fmol) and linear detector response over two concentration orders in the pico- and femtomolar range are extremely encouraging for the direct study of such acids in complex biological matrices.

  12. LVDS tester: a systematic test of cable signal transmission at the ALICE experiment

    NASA Astrophysics Data System (ADS)

    Barnby, L.; Bhasin, A.; Bombara, M.; Evans, D.; Jones, G. T.; Jones, P. G.; Jovanović, P.; Jusko, A.; Kour, R.; Králik, I.; Krivda, M.; Lazzeroni, C.; Lietava, R.; Matthews, Z. L.; Navin, S.; Palaha, A.; Petrov, P.; Platt, R.; Šándor, L.; Scott, P.; Urbán, J.; Villalobos Baillie, O.; Tapia Takaki, J. D.

    2010-12-01

    In the ALICE experiment, the Low-Voltage Differential Signalling (LVDS) format is used for the transmission of trigger inputs from the detectors to the Central Trigger Processor (CTP), the L0 trigger outputs from Local Trigger Units (LTU) boards back to the detectors and the BUSY inputs from the sub-detectors to the CTP. ALICE has designed a set-up, called the LVDS transmission tester, that aims to measure various transmission quality parameters and the bit-error rate (BER) for long period runs in an automatic way. In this paper, this method is described and the conclusions from these tests for the ALICE LVDS cables are discussed.

  13. Invited Article: Characterization of background sources in space-based time-of-flight mass spectrometers

    SciTech Connect

    Gilbert, J. A.; Gershman, D. J.; Gloeckler, G.; Lundgren, R. A.; Zurbuchen, T. H.; Orlando, T. M.; McLain, J.; Steiger, R. von

    2014-09-15

    For instruments that use time-of-flight techniques to measure space plasma, there are common sources of background signals that evidence themselves in the data. The background from these sources may increase the complexity of data analysis and reduce the signal-to-noise response of the instrument, thereby diminishing the science value or usefulness of the data. This paper reviews several sources of background commonly found in time-of-flight mass spectrometers and illustrates their effect in actual data using examples from ACE-SWICS and MESSENGER-FIPS. Sources include penetrating particles and radiation, UV photons, energy straggling and angular scattering, electron stimulated desorption of ions, ion-induced electron emission, accidental coincidence events, and noise signatures from instrument electronics. Data signatures of these sources are shown, as well as mitigation strategies and design considerations for future instruments.

  14. Invited article: Characterization of background sources in space-based time-of-flight mass spectrometers.

    PubMed

    Gilbert, J A; Gershman, D J; Gloeckler, G; Lundgren, R A; Zurbuchen, T H; Orlando, T M; McLain, J; von Steiger, R

    2014-09-01

    For instruments that use time-of-flight techniques to measure space plasma, there are common sources of background signals that evidence themselves in the data. The background from these sources may increase the complexity of data analysis and reduce the signal-to-noise response of the instrument, thereby diminishing the science value or usefulness of the data. This paper reviews several sources of background commonly found in time-of-flight mass spectrometers and illustrates their effect in actual data using examples from ACE-SWICS and MESSENGER-FIPS. Sources include penetrating particles and radiation, UV photons, energy straggling and angular scattering, electron stimulated desorption of ions, ion-induced electron emission, accidental coincidence events, and noise signatures from instrument electronics. Data signatures of these sources are shown, as well as mitigation strategies and design considerations for future instruments.

  15. Study of ultrasonic thermometry based on ultrasonic time-of-flight measurement

    NASA Astrophysics Data System (ADS)

    Jia, Ruixi; Xiong, Qingyu; Wang, Lijie; Wang, Kai; Shen, Xuehua; Liang, Shan; Shi, Xin

    2016-03-01

    Ultrasonic thermometry is a kind of acoustic pyrometry and it has been evolving as a new temperature measurement technology for various environment. However, the accurate measurement of the ultrasonic time-of-flight is the key for ultrasonic thermometry. In this paper, we study the ultrasonic thermometry technique based on ultrasonic time-of-flight measurement with a pair of ultrasonic transducers for transmitting and receiving signal. The ultrasonic transducers are installed in a single path which ultrasonic travels. In order to validate the performance of ultrasonic thermometry, we make a contrast about the absolute error between the measured temperature value and the practical one. With and without heater source, the experimental results indicate ultrasonic thermometry has high precision of temperature measurement.

  16. A Metrological Based Realization of Time-of-Flight Diffraction Technique

    NASA Astrophysics Data System (ADS)

    Mayworm, Ruan C.; Alvarenga, Andre V.; Costa-Felix, Rodrigo P. B.

    Time-of-Flight Diffraction (ToFD) is a technique of non-destructive testing by ultrasound used for detecting faults and discontinuities in different components. The development and implementation of this technique was based on ISO 16828:2012 (Non-Destructive testing - Ultrasonic Testing - Time-of-Flight Diffraction Technique as a method for Detection and Sizing of Discontinuities). Controlling the different characteristics of the system, from the specification of the ultrasonic characteristics, to the imaging technique, was possible to identify the sources of uncertainty and estimate the ToFD measurement uncertainty. For a 25 mm deep stainless steel test object, expanded uncertainties less than 0.5%(0.093 mm) was achieved with ToFD. For larger ultrasonic paths, the technique is able to depict even lower uncertainties, regarding some care are taken in the ultrasonic measurement setup.

  17. Time-of-flight measurement with femtosecond pulses for high precision ranging lidar

    NASA Astrophysics Data System (ADS)

    Lee, J.; Kim, Y.-J.; Lee, K.; Lee, S.; Kim, S.-W.

    2010-10-01

    The time-of-flight of light pulses has long been used as a direct measure of distance, but the state-of-the-art measurement precision using conventional light pulses or microwaves reaches only several hundreds of micromeres. This is due to the bandwidth limit of the photodetectors available today, which is in the picosecond range at best. Here, we improve the time-of-flight precision to the nanometer regime by timing femtosecond pulses through phase-locking control of the pulse repetition rate using the optical cross-correlation technique that exploits a second-harmonic birefringence crystal and a balance photodetector. The enhanced capability is maintained at long range without periodic ambiguity, being well suited to terrestrial lidar applications such as geodetic surveying, range finders and absolute altimeters. This method could also be applied to future space missions of formation-flying satellites for synthetic aperture imaging and remote experiments related to the general relativity theory.

  18. Nitrogen depth profiling using recoil-nucleus time-of-flight spectrometry

    SciTech Connect

    Welsh, J.F. Jr.; Schweikert, E.A.

    1994-12-31

    Neutron depth profiling (NDP) has been shown to be an effective research tool for the profiling of light elements. Significant increases in sensitivity like those realized at the cold neutron NDP facility at the National Institute of Standards and Technology (NIST) reactor continue to advance the technique. Previous work has also shown that the depth resolution of NDP could be improved by measuring (via time of flight) the kinetic energies of recoil nuclei emitted during (n,p) and (n, {alpha}) reactions. The purpose of this work was to extend the technique of recoil-nucleus time-of-flight (TOF) NDP (RN-TOF-NDP) to the profiling of nitrogen in silicon nitride using the {sup 14}N(n,p) {sup 14}C reaction.

  19. A compact time-of-flight mass spectrometer for ion source characterization

    SciTech Connect

    Chen, L. Wan, X.; Jin, D. Z.; Tan, X. H.; Huang, Z. X.; Tan, G. B.

    2015-03-15

    A compact time-of-flight mass spectrometer with overall dimension of about 413 × 250 × 414 mm based on orthogonal injection and angle reflection has been developed for ion source characterization. Configuration and principle of the time-of-flight mass spectrometer are introduced in this paper. The mass resolution is optimized to be about 1690 (FWHM), and the ion energy detection range is tested to be between about 3 and 163 eV with the help of electron impact ion source. High mass resolution and compact configuration make this spectrometer useful to provide a valuable diagnostic for ion spectra fundamental research and study the mass to charge composition of plasma with wide range of parameters.

  20. Ambient aerosol analysis using aerosol-time-of-flight mass spectrometry

    SciTech Connect

    Prather, K.A.; Noble, C.A.; Liu, D.Y.; Silva, P.J.; Fergenson, D.F.

    1996-10-01

    We have recently developed a technique, Aerosol-Time-of-Flight Mass Spectrometry (ATOFMS), which is capable of real-time determination of the aerodynamic size and chemical composition of individual aerosol particles. In order to obtain such information, the techniques of aerodynamic particle sizing and time-of-flight mass spectrometry are combined in a single instrument. ATOFMS is being used for the direct analysis of ambient aerosols with the goal of establishing correlations between particle size and chemical composition. Currently, measurements are being made to establish potential links between the presence of particular types of particles with such factors as the time of day, weather conditions, and concentration levels of gaseous smog components such as NO{sub x} and ozone. This data will be used to help establish a better understanding of tropospheric gas-aerosol processes. This talk will discuss the operating principles of ATOFMS as well as present the results of ambient analysis studies performed in our laboratory.

  1. Time of flight measurements of unirradiated and irradiated nuclear graphite under cyclic compressive load

    NASA Astrophysics Data System (ADS)

    Bodel, W.; Atkin, C.; Marsden, B. J.

    2017-04-01

    The time-of-flight technique has been used to investigate the stiffness of nuclear graphite with respect to the grade and grain direction. A loading rig was developed to collect time-of-flight measurements during cycled compressive loading up to 80% of the material's compressive strength and subsequent unloading of specimens along the axis of the applied stress. The transmission velocity (related to Young's modulus), decreased with increasing applied stress; and depending on the graphite grade and orientation, the modulus then increased, decreased or remained constant upon unloading. These tests were repeated while observing the microstructure during the load/unload cycles. Initial decreases in transmission velocity with compressive load are attributed to microcrack formation within filler and binder phases. Three distinct types of behaviour occur on unloading, depending on the grade, irradiation, and loading direction. These different behaviours can be explained in terms of the material microstructure observed from the microscopy performed during loading.

  2. Limitation of Time-of-Flight Resolution in the Ultra High Mass Range

    PubMed Central

    Lee, Jeonghoon

    2011-01-01

    In this work, we have examined the reason for the deterioration of resolution and mass accuracy of time-of-flight mass analyzers with increasing mass after the expansion induced kinetic energy has been eliminated by collisional cooling in an ion guide. Theoretically, removing the expansion–induced kinetic energy by collisional cooling permits the ions to travel along the ion guide axes without significant deviation so that they can be injected into the analyzer in a well-collimated ion beam with well-defined kinetic energy. If the ions can be injected into an orthogonal acceleration time-of-flight mass analyzer (oa-TOF) in this manner, high resolution mass analysis can be obtained regardless of mass or m/z. Unfortunately, high resolution did not result. It is our contention that the effusive expansion out of the first ion guide yields dispersive axial ejection that reduces TOF resolving power with increasing mass not m/z. PMID:21728303

  3. Comparison between triple quadrupole, time of flight and hybrid quadrupole time of flight analysers coupled to liquid chromatography for the detection of anabolic steroids in doping control analysis.

    PubMed

    Pozo, Oscar J; Van Eenoo, Peter; Deventer, Koen; Elbardissy, Hisham; Grimalt, Susana; Sancho, Juan V; Hernandez, Felix; Ventura, Rosa; Delbeke, Frans T

    2011-01-17

    Triple quadrupole (QqQ), time of flight (TOF) and quadrupole-time of flight (QTOF) analysers have been compared for the detection of anabolic steroids in human urine. Ten anabolic steroids were selected as model compounds based on their ionization and the presence of endogenous interferences. Both qualitative and quantitative analyses were evaluated. QqQ allowed for the detection of all analytes at the minimum required performance limit (MRPL) established by the World Anti-Doping Agency (between 2 and 10 ng mL(-1) in urine). TOF and QTOF approaches were not sensitive enough to detect some of the analytes (3'-hydroxy-stanozolol or the metabolites of boldenone and formebolone) at the established MRPL. Although a suitable accuracy was obtained, the precision was unsatisfactory (RSD typically higher than 20%) for quantitative purposes irrespective of the analyser used. The methods were applied to 30 real samples declared positives either for the misuse of boldenone, stanozolol and/or methandienone. Most of the compounds were detected by every technique, however QqQ was necessary for the detection of some metabolites in a few samples. Finally, the possibility to detect non-target steroids has been explored by the use of TOF and QTOF. The use of this approach revealed that the presence of boldenone and its metabolite in one sample was due to the intake of androsta-1,4,6-triene-3,17-dione. Additionally, the intake of methandienone was confirmed by the post-target detection of a long-term metabolite.

  4. Implementation of a new type of time-of-flight laser anemometer

    NASA Technical Reports Server (NTRS)

    Wernet, M. P.; Edwards, R. V.

    1986-01-01

    A new time-of-flight (TOF) laser anemometer system utilizing a spatial lead-lag filter for bipolar pulse generation has been constructed and tested. This new TOF has been modified to enable measurements in turbulent flows near walls. Good results have been obtained as close as 100 microns from a surface, with a 140-mm focal length final lens. Lading's theory for the behavior of the measurement variance has been confirmed for this configuration.

  5. Fully digital data acquisition system for the neutron time-of-flight spectrometer TOFOR at JET.

    PubMed

    Skiba, M; Weiszflog, M; Hjalmarsson, A; Ericsson, G; Hellesen, C; Conroy, S; Andersson-Sundén, E; Eriksson, J; Binda, F

    2012-10-01

    A prototype of a fully digital data acquisition system based on 1 Gsps 12 bit digitizers for the TOFOR fusion neutron spectrometer at JET is assessed. The prototype system enables the use of geometry-based background discrimination techniques, which are modeled, evaluated, and compared to experimental data. The experimental results are in line with the models and show a significant improvement in signal-to-background ratio in measured time-of-flight spectrum compared to the existing data acquisition system.

  6. Semen quality detection using time of flight and acoustic wave sensors

    SciTech Connect

    Newton, M. I.; Evans, C. R.; Simons, J. J.; Hughes, D. C.

    2007-04-09

    The authors report a real-time technique for assessing the number of motile sperm in a semen sample. The time of flight technique uses a flow channel with detection at the end of the channel using quartz crystal microbalances. Data presented suggest that a simple rigid mass model may be used in interpreting the change in resonant frequency using an effective mass for the sperm.

  7. Implementation of a new type of time-of-flight laser anemometer.

    PubMed

    Wernet, M P; Edwards, R V

    1986-03-01

    A new time-of-flight (TOF) laser anemometer system utilizing a spatial lead-lag filter for bipolar pulse generation has been constructed and tested. This new TOF has been modified to enable measurements in turbulent flows near walls. Good results have been obtained as close as 100 microm from a surface, with a 140-mm focal length final lens. Lading's theory for the behavior of the measurement variance has been confirmed for this configuration.

  8. Neutron-induced fission measurements at the time-of-flight facility nELBE

    SciTech Connect

    Kögler, T.; Junghans, A. R.; Massarczyk, R.; Schwengner, R.; Wagner, A.

    2015-05-18

    Neutron-induced fission of ²⁴²Pu is studied at the photoneutron source nELBE. The relative fast neutron fission cross section was determined using actinide fission chambers in a time-of-flight experiment. A good agreement of present nuclear data with evalua- tions has been achieved in the range of 100 keV to 10 MeV.

  9. Contactless flow measurement in liquid metal using electromagnetic time-of-flight method

    NASA Astrophysics Data System (ADS)

    Dubovikova, Nataliia; Resagk, Christian; Karcher, Christian; Kolesnikov, Yuri

    2016-05-01

    Measuring flow rates of liquid metal flows is of utmost importance in industrial applications such as metal casting, in order to ensure process efficiency and product quality. A non-contact method for flow rate control is described here. The method is known as time-of-flight Lorentz force velocimetry (LFV) and determines flow rate through measurement of Lorentz force that act on magnet systems that are placed close to the flow. In this method, a vortex generator is used to generate an eddy in the flow, with two magnet systems separated by a known distance placed downstream of the vortex generator. Each of the magnet systems has a force sensor attached to them which detects the passing of the eddy through its magnetic field as a significant perturbation in the force signal. The flow rate is estimated from the time span between the perturbations in the two force signals. In this paper, time-of-flight LFV technique is demonstrated experimentally for the case of liquid metal flow in a closed rectangular duct loop that is driven by an electromagnetic pump. A liquid metal alloy of gallium (Ga), indium (In) and tin (Sn)—GaInSn—is used as the working fluid. In contrast to prior works, for the first time, three-dimensional strain gauge force sensors were used for measuring Lorentz force to investigate the effect of flow disturbances in different directions for flow measurements by the time-of-flight LFV method. A prototype time-of-flight LFV flowmeter is developed, the operation of which in laboratory conditions is characterised by different experiments.

  10. The time-of-flight spectrometer with cold neutrons at the FRM-II

    NASA Astrophysics Data System (ADS)

    Zirkel, A.; Roth, S.; Schneider, W.; Neuhaus, J.; Petry, W.

    2000-03-01

    We are presenting a design study of the new cold-time-of-flight spectrometer to be built at the FRM-II. Monte Carlo techniques were used to optimize the flux at the sample position and to calculate the elastic energy resolution. A doubly focusing neutron guide is used to enhance the intensity on the sample. Magnetic bearings and carbon fiber composite disks will give access to very high chopper speeds, thereby considerably increasing the overall performance of the instrument.

  11. Acetazolamide challenge for three-dimensional time-of-flight MR angiography of the brain

    SciTech Connect

    Mandai, Kenji; Sueyoshi, Kenji; Fukunaga, Ryuzo; Nukada, Masaru; Ohtani, Fumio; Araki, Yutaka; Tsukaguchi, Isao; Abe, Hiroshi )

    1994-04-01

    We compared three-dimensional time-of-flight MR angiograms obtained before and after acetazolamide administration to evaluate whether use of this drug could improve visualization of small peripheral intracranial arteries and atherosclerotic stenosis. For evaluation of small peripheral arteries, 10 patients with clinical diagnosis of ischemic cerebrovascular disease and 10 healthy volunteers were investigated, and for evaluation of stenosis, another 6 patients were investigated. Vascular images were obtained by three-dimensional time-of-flight MR angiography. After a baseline scan, 17 mg/kg acetazolamide was injected intravenously and the second scan was performed 20 minutes later. Several small peripheral arteries that had not been seen on the baseline images were visible on the acetazolamide images without any augmentation of the background signals. Stenotic lesions in the main trunks of the major cerebral arteries were detected more clearly on acetazolamide images. Acetazolamide improves visualization of small peripheral intracranial arteries and sensitivity in detecting atherosclerotic stenosis in the main trunk of major cerebral artery by three-dimensional time-of-flight MR angiography without changing MR apparatus and software. 15 refs., 5 figs., 2 tabs.

  12. Nanometer scale elemental analysis in the helium ion microscope using time of flight spectrometry.

    PubMed

    Klingner, N; Heller, R; Hlawacek, G; von Borany, J; Notte, J; Huang, J; Facsko, S

    2016-03-01

    Time of flight backscattering spectrometry (ToF-BS) was successfully implemented in a helium ion microscope (HIM). Its integration introduces the ability to perform laterally resolved elemental analysis as well as elemental depth profiling on the nm scale. A lateral resolution of ≤54nm and a time resolution of Δt≤17ns(Δt/t≤5.4%) are achieved. By using the energy of the backscattered particles for contrast generation, we introduce a new imaging method to the HIM allowing direct elemental mapping as well as local spectrometry. In addition laterally resolved time of flight secondary ion mass spectrometry (ToF-SIMS) can be performed with the same setup. Time of flight is implemented by pulsing the primary ion beam. This is achieved in a cost effective and minimal invasive way that does not influence the high resolution capabilities of the microscope when operating in standard secondary electron (SE) imaging mode. This technique can thus be easily adapted to existing devices. The particular implementation of ToF-BS and ToF-SIMS techniques are described, results are presented and advantages, difficulties and limitations of this new techniques are discussed.

  13. Upgrade of the ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    Kushpil, Svetlana; ALICE Collaboration

    2016-02-01

    ALICE detector was constructed to study the properties of hot and dense hadronic matter formed in relativistic nuclear collisions. During the second long LHC shutdown in 2019-2020, the collaboration plans to upgrade the current vertex detector, the Inner Tracking System (ITS), in order to increase the reconstruction accuracy of secondary vertices and to lower the threshold of particle transverse momentum measurement. The upgrade strategy of ITS is based on the application of new Monolithic Active Pixel Sensors (MAPS) designed in 0.18 μm CMOS technology. The 50 μm thick chip consists of a single silicon die incorporating a 0.18 μm high-resistivity silicon epitaxial layer (sensor active volume) and matrix of charge collection diodes (pixels) with readout electronics. Radiation hardness of the upgraded ITS is one of the crucial moments in the overall performance of the system. A wide set of MAPS structures with different read-out circuits was produced and is being studied by the ALICE collaboration to optimize the pixel sensor functionality. An overview of the ALICE ITS upgrade and the expected performance improvement will be presented together with selected results from a campaign that includes several irradiation and beam tests.

  14. Single transmission-line readout method for silicon photomultiplier based time-of-flight and depth-of-interaction PET

    NASA Astrophysics Data System (ADS)

    Ko, Guen Bae; Lee, Jae Sung

    2017-03-01

    We propose a novel single transmission-line readout method for whole-body time-of-flight positron emission tomography applications, without compromising on performance. The basic idea of the proposed multiplexing method is the addition of a specially prepared tag signal ahead of the scintillation pulse. The tag signal is a square pulse that encodes photon arrival time and channel information. The 2D position of a silicon photomultiplier (SiPM) array is encoded by the specific width and height of the tag signal. A summing amplifier merges the tag and scintillation signals of each channel, and the final output signal can be acquired with a one-channel digitizer. The feasibility and performance of the proposed method were evaluated using a 1:1 coupled detector consisting of 4  ×  4 array of LGSO crystals and 16 channel SiPM. The sixteen 3 mm LGSO crystals were clearly separated in the crystal-positioning map with high reliability. The average energy resolution and coincidence resolving time were 11.31  ±  0.55% and 264.7  ±  10.7 ps, respectively. We also proved that the proposed method does not degrade timing performance with increasing multiplexing ratio. The two types of LGSO crystals (L0.95GSO and L0.20GSO) in phoswich detector were also clearly identified with the high-reliability using pulse shape discrimination, thanks to the well-preserved pulse shape information. In conclusion, the proposed multiplexing method allows decoding of the 3D interaction position of gamma rays in the scintillation detector with single-line readout.

  15. Single transmission-line readout method for silicon photomultiplier based time-of-flight and depth-of-interaction PET.

    PubMed

    Ko, Guen Bae; Lee, Jae Sung

    2017-01-18

    We propose a novel single transmission-line readout method for whole-body time-of-flight positron emission tomography applications, without compromising on performance. The basic idea of the proposed multiplexing method is the addition of a specially prepared tag signal ahead of the scintillation pulse. The tag signal is a square pulse that encodes photon arrival time and channel information. The 2D position of a silicon photomultiplier (SiPM) array is encoded by the specific width and height of the tag signal. A summing amplifier merges the tag and scintillation signals of each channel, and the final output signal can be acquired with a one-channel digitizer. The feasibility and performance of the proposed method were evaluated using a 1:1 coupled detector consisting of 4  ×  4 array of LGSO crystals and 16 channel SiPM. The sixteen 3 mm LGSO crystals were clearly separated in the crystal-positioning map with high reliability. The average energy resolution and coincidence resolving time were 11.31  ±  0.55% and 264.7  ±  10.7 ps, respectively. We also proved that the proposed method does not degrade timing performance with increasing multiplexing ratio. The two types of LGSO crystals (L0.95GSO and L0.20GSO) in phoswich detector were also clearly identified with the high-reliability using pulse shape discrimination, thanks to the well-preserved pulse shape information. In conclusion, the proposed multiplexing method allows decoding of the 3D interaction position of gamma rays in the scintillation detector with single-line readout.

  16. (A new time of flight) Acoustic flow meter using wide band signals and adaptive beamforming techniques

    NASA Astrophysics Data System (ADS)

    Murgan, I.; Ioana, C.; Candel, I.; Anghel, A.; Ballester, J. L.; Reeb, B.; Combes, G.

    2016-11-01

    In this paper we present the result of our research concerning the improvement of acoustic time of flight flow metering for water pipes. Current flow meters are based on the estimation of direct time of flight by matched filtering of the received and emitted signals by acoustic transducers. Currently, narrow band signals are used, as well as a single emitter/receptor transducer configuration. Although simple, this configuration presents a series of limitations such as energy losses due to pipe wall/water interface, pressure/flow transients, sensitivity to flow induced vibrations, acoustic beam deformations and shift due to changes in flow velocity and embedded turbulence in the flow. The errors associated with these limitations reduce the overall robustness of existing flow meters, as well as the measured flow rate range and lower accuracy. In order to overcome these limitations, two major innovations were implemented at the signal processing level. The first one concerns the use of wide band signals that optimise the power transfer throughout the acoustic path and also increase the number of velocity/flow readings per second. Using wide band signals having a high duration-bandwidth product increases the precision in terms of time of flight measurements and, in the same time, improves the system robustness. The second contribution consists in the use of a multiple emitter - multiple receivers configuration (for one path) in order to compensate the emitted acoustic beam shift, compensate the time of flight estimation errors and thus increase the flow meter's robustness in case of undesired effects such as the “flow blow” and transient/rapid flow rate/velocity changes. Using a new signal processing algorithm that take advantage of the controlled wide band content coming from multiple receivers, the new flow meters achieves a higher accuracy in terms of flow velocity over a wider velocity range than existing systems. Tests carried out on real scale experimental

  17. Alice in Debitland.

    ERIC Educational Resources Information Center

    Board of Governors of the Federal Reserve System, Washington, DC.

    Designed for the general public and possibly suitable also for high school economics students, this booklet examines the Electronic Fund Transfer Act (EFT), which protects consumers who use debit cards for the electronic transfer of funds. This commercially adapted version of the character in "Alice in Wonderland," uses a story-teller…

  18. Upgrade of the ALICE Inner Tracking System

    NASA Astrophysics Data System (ADS)

    Belikov, Iouri

    2016-10-01

    A Large Ion Collider Experiment (ALICE) is built to study the properties of the strongly interacting matter created in heavy-ion collisions at the LHC. With the upgrade of its Inner Tracking System (ITS), the ALICE experiment is going to increase the rate of data taking by almost two orders of magnitude. At the same time, the precision of secondary vertex reconstruction will become by at least a factor 3 better than it currently is. In this talk, we briefly show some selected physics results motivating the upgrade of the ITS, describe the design goals and the layout of the new detector, and highlight a few important measurements that will be realized after the completion of this upgrade.

  19. Determination of absorption changes from moments of distributions of times of flight of photons: optimization of measurement conditions for a two-layered tissue model

    NASA Astrophysics Data System (ADS)

    Liebert, Adam; Wabnitz, Heidrun; Elster, Clemens

    2012-05-01

    Time-resolved near-infrared spectroscopy allows for depth-selective determination of absorption changes in the adult human head that facilitates separation between cerebral and extra-cerebral responses to brain activation. The aim of the present work is to analyze which combinations of moments of measured distributions of times of flight (DTOF) of photons and source-detector separations are optimal for the reconstruction of absorption changes in a two-layered tissue model corresponding to extra- and intra-cerebral compartments. To this end we calculated the standard deviations of the derived absorption changes in both layers by considering photon noise and a linear relation between the absorption changes and the DTOF moments. The results show that the standard deviation of the absorption change in the deeper (superficial) layer increases (decreases) with the thickness of the superficial layer. It is confirmed that for the deeper layer the use of higher moments, in particular the variance of the DTOF, leads to an improvement. For example, when measurements at four different source-detector separations between 8 and 35 mm are available and a realistic thickness of the upper layer of 12 mm is assumed, the inclusion of the change in mean time of flight, in addition to the change in attenuation, leads to a reduction of the standard deviation of the absorption change in the deeper tissue layer by a factor of 2.5. A reduction by another 4% can be achieved by additionally including the change in variance.

  20. Physical and clinical performance of the mCT time-of-flight PET/CT scanner

    NASA Astrophysics Data System (ADS)

    Jakoby, B. W.; Bercier, Y.; Conti, M.; Casey, M. E.; Bendriem, B.; Townsend, D. W.

    2011-04-01

    Time-of-flight (TOF) measurement capability promises to improve PET image quality. We characterized the physical and clinical PET performance of the first Biograph mCT TOF PET/CT scanner (Siemens Medical Solutions USA, Inc.) in comparison with its predecessor, the Biograph TruePoint TrueV. In particular, we defined the improvements with TOF. The physical performance was evaluated according to the National Electrical Manufacturers Association (NEMA) NU 2-2007 standard with additional measurements to specifically address the TOF capability. Patient data were analyzed to obtain the clinical performance of the scanner. As expected for the same size crystal detectors, a similar spatial resolution was measured on the mCT as on the TruePoint TrueV. The mCT demonstrated modestly higher sensitivity (increase by 19.7 ± 2.8%) and peak noise equivalent count rate (NECR) (increase by 15.5 ± 5.7%) with similar scatter fractions. The energy, time and spatial resolutions for a varying single count rate of up to 55 Mcps resulted in 11.5 ± 0.2% (FWHM), 527.5 ± 4.9 ps (FWHM) and 4.1 ± 0.0 mm (FWHM), respectively. With the addition of TOF, the mCT also produced substantially higher image contrast recovery and signal-to-noise ratios in a clinically-relevant phantom geometry. The benefits of TOF were clearly demonstrated in representative patient images.

  1. First spatial separation of a heavy ion isomeric beam with a multiple-reflection time-of-flight mass spectrometer

    NASA Astrophysics Data System (ADS)

    Dickel, T.; Plaß, W. R.; Ayet San Andres, S.; Ebert, J.; Geissel, H.; Haettner, E.; Hornung, C.; Miskun, I.; Pietri, S.; Purushothaman, S.; Reiter, M. P.; Rink, A.-K.; Scheidenberger, C.; Weick, H.; Dendooven, P.; Diwisch, M.; Greiner, F.; Heiße, F.; Knöbel, R.; Lippert, W.; Moore, I. D.; Pohjalainen, I.; Prochazka, A.; Ranjan, M.; Takechi, M.; Winfield, J. S.; Xu, X.

    2015-05-01

    211Po ions in the ground and isomeric states were produced via 238U projectile fragmentation at 1000 MeV/u. The 211Po ions were spatially separated in flight from the primary beam and other reaction products by the fragment separator FRS. The ions were energy-bunched, slowed-down and thermalized in a gas-filled cryogenic stopping cell (CSC). They were then extracted from the CSC and injected into a high-resolution multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). The excitation energy of the isomer and, for the first time, the isomeric-to-ground state ratio were determined from the measured mass spectrum. In the subsequent experimental step, the isomers were spatially separated from the ions in the ground state by an ion deflector and finally collected with a silicon detector for decay spectroscopy. This pioneering experimental result opens up unique perspectives for isomer-resolved studies. With this versatile experimental method new isomers with half-lives longer than a few milliseconds can be discovered and their decay properties can be measured with highest sensitivity and selectivity. These experiments can be extended to studies with isomeric beams in nuclear reactions.

  2. A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

    SciTech Connect

    Arrell, C. A. Ojeda, J.; Mourik, F. van; Chergui, M.; Sabbar, M.; Gallmann, L.; Keller, U.; Okell, W. A.; Witting, T.; Siegel, T.; Diveki, Z.; Hutchinson, S.; Tisch, J. W.G.; Marangos, J. P.; Chapman, R. T.; Cacho, C.; Rodrigues, N.; Turcu, I. C.E.; Springate, E.

    2014-10-01

    We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10⁻¹ mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

  3. 63Cu(n ,γ ) cross section measured via 25 keV activation and time of flight

    NASA Astrophysics Data System (ADS)

    Weigand, M.; Beinrucker, C.; Couture, A.; Fiebiger, S.; Fonseca, M.; Göbel, K.; Heftrich, M.; Heftrich, T.; Jandel, M.; Käppeler, F.; Krása, A.; Lederer, C.; Lee, H. Y.; Plag, R.; Plompen, A.; Reifarth, R.; Schmidt, S.; Sonnabend, K.; Ullmann, J. L.

    2017-01-01

    In the nuclear mass range A ≈60 to 90 of the solar abundance distribution the weak s -process component is the dominant contributor. In this scenario, which is related to massive stars, the overall neutron exposure is not sufficient for the s process to reach mass flow equilibrium. Hence, abundances and isotopic ratios are very sensitive to the neutron capture cross sections of single isotopes, and nucleosynthesis models need accurate experimental data. In this work we report on a new measurement of the 63Cu(n ,γ ) cross section for which the existing experimental data show large discrepancies. The 63Cu(n ,γ ) cross section at kBT =25 keV was determined via activation with a quasistellar neutron spectrum at the Joint Research Centre (JRC) in Geel, and the energy dependence was determined with the time-of-flight technique and the calorimetric 4 π BaF2 detector array DANCE at the Los Alamos National Laboratory. We provide new cross section data for the whole astrophysically relevant energy range.

  4. Blind quantum computation protocol in which Alice only makes measurements

    NASA Astrophysics Data System (ADS)

    Morimae, Tomoyuki; Fujii, Keisuke

    2013-05-01

    Blind quantum computation is a new secure quantum computing protocol which enables Alice (who does not have sufficient quantum technology) to delegate her quantum computation to Bob (who has a full-fledged quantum computer) in such a way that Bob cannot learn anything about Alice's input, output, and algorithm. In previous protocols, Alice needs to have a device which generates quantum states, such as single-photon states. Here we propose another type of blind computing protocol where Alice does only measurements, such as the polarization measurements with a threshold detector. In several experimental setups, such as optical systems, the measurement of a state is much easier than the generation of a single-qubit state. Therefore our protocols ease Alice's burden. Furthermore, the security of our protocol is based on the no-signaling principle, which is more fundamental than quantum physics. Finally, our protocols are device independent in the sense that Alice does not need to trust her measurement device in order to guarantee the security.

  5. Production of pions, kaons and protons in pp collisions at sqrt{s}= 900 GeV with ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Aamodt, K.; Abel, N.; Abeysekara, U.; Abrahantes Quintana, A.; Abramyan, A.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agocs, A. G.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad, A.; Ahmad, N.; Ahn, S. U.; Akimoto, R.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Almaráz Aviña, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Andrei, C.; Andronic, A.; Anelli, G.; Angelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antinori, S.; Antipin, K.; Antończyk, D.; Antonioli, P.; Anzo, A.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arceo, R.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bablok, S.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baldit, A.; Bán, J.; Barbera, R.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Barile, F.; Basile, M.; Basmanov, V.; Bastid, N.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I. G.; Becker, B.; Belikov, I.; Bellwied, R.; Belmont-Moreno, E.; Belogianni, A.; Benhabib, L.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bimbot, L.; Biolcati, E.; Blanc, A.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Bohm, J.; Boldizsár, L.; Bombara, M.; Bombonati, C.; Bondila, M.; Borel, H.; Borisov, A.; Bortolin, C.; Bose, S.; Bosisio, L.; Bossú, F.; Botje, M.; Böttger, S.; Bourdaud, G.; Boyer, B.; Braun, M.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Breitner, T.; Bruckner, G.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo, E.; Camacho, E.; Camerini, P.; Campbell, M.; Canoa Roman, V.; Capitani, G. P.; Romeo, G. Cara; Carena, F.; Carena, W.; Carminati, F.; Casanova Díaz, A.; Caselle, M.; Castillo Castellanos, J.; Castillo Hernandez, J. F.; Catanescu, V.; Cattaruzza, E.; Cavicchioli, C.; Cerello, P.; Chambert, V.; Chang, B.; Chapeland, S.; Charpy, A.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chiavassa, E.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chuman, F.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Cobanoglu, O.; Coffin, J.-P.; Coli, S.; Colla, A.; Conesa Balbastre, G.; Conesa del Valle, Z.; Conner, E. S.; Constantin, P.; Contin, G.; Contreras, J. G.; Corrales Morales, Y.; Cormier, T. M.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Cussonneau, J.; Dainese, A.; Dalsgaard, H. H.; Danu, A.; Das, I.; Dash, A.; Dash, S.; de Barros, G. O. V.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gaspari, M.; de Groot, J.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Remigis, R.; de Rooij, R.; de Vaux, G.; Delagrange, H.; Delgado, Y.; Dellacasa, G.; Deloff, A.; Demanov, V.; Dénes, E.; Deppman, A.; D'Erasmo, G.; Derkach, D.; Devaux, A.; Di Bari, D.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Dialinas, M.; Díaz, L.; Díaz, R.; Dietel, T.; Divià, R.; Djuvsland, Ø.; Dobretsov, V.; Dobrin, A.; Dobrowolski, T.; Dönigus, B.; Domínguez, I.; Don, D. M. M.; Dordic, O.; Dubey, A. K.; Dubuisson, J.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Dutta Majumdar, M. R.; Elia, D.; Emschermann, D.; Engel, H.; Enokizono, A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evrard, S.; Eyyubova, G.; Fabjan, C. W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fateev, O.; Fearick, R.; Fedunov, A.; Fehlker, D.; Fekete, V.; Felea, D.; Fenton-Olsen, B.; Feofilov, G.; Téllez, A. Fernández; Ferreiro, E. G.; Ferretti, A.; Ferretti, R.; Figueredo, M. A. S.; Filchagin, S.; Fini, R.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Fodor, Z.; Foertsch, S.; Foka, P.; Fokin, S.; Formenti, F.; Fragiacomo, E.; Fragkiadakis, M.; Frankenfeld, U.; Frolov, A.; Fuchs, U.; Furano, F.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gallio, M.; Ganoti, P.; Ganti, M. S.; Garabatos, C.; García Trapaga, C.; Gebelein, J.; Gemme, R.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Giraudo, G.; Giubellino, P.; Gladysz-Dziadus, E.; Glasow, R.; Glässel, P.; Glenn, A.; Jiménez, R. Gómez; González Santos, H.; González-Trueba, L. H.; González-Zamora, P.; Gorbunov, S.; Gorbunov, Y.; Gotovac, S.; Gottschlag, H.; Grabski, V.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerra, C.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Gustafsson, H.-A.; Gutbrod, H.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamblen, J.; Han, B. H.; Harris, J. W.; Hartig, M.; Harutyunyan, A.; Hasch, D.; Hasegan, D.; Hatzifotiadou, D.; Hayrapetyan, A.; Heide, M.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Hernández, C.; Herrera Corral, G.; Herrmann, N.; Hetland, K. F.; Hicks, B.; Hiei, A.; Hille, P. T.; Hippolyte, B.; Horaguchi, T.; Hori, Y.; Hristov, P.; Hřivnáčová, I.; Hu, S.; Huang, M.; Huber, S.; Humanic, T. J.; Hutter, D.; Hwang, D. S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Innocenti, P. G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Iwasaki, T.; Jachołkowski, A.; Jacobs, P.; Jančurová, L.; Jangal, S.; Janik, R.; Jena, C.; Jena, S.; Jirden, L.; Jones, G. T.; Jones, P. G.; Jovanović, P.; Jung, H.; Jung, W.; Jusko, A.; Kaidalov, A. B.; Kalcher, S.; Kaliňák, P.; Kalisky, M.; Kalliokoski, T.; Kalweit, A.; Kamal, A.; Kamermans, R.; Kanaki, K.; Kang, E.; Kang, J. H.; Kapitan, J.; Kaplin, V.; Kapusta, S.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Khan, M. M.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kikola, D.; Kileng, B.; Kim, D. J.; Kim, D. S.; Kim, D. W.; Kim, H. N.; Kim, J.; Kim, J. H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S. H.; Kim, S.; Kim, Y.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kliemant, M.; Klovning, A.; Kluge, A.; Knichel, M. L.; Kniege, S.; Koch, K.; Kolevatov, R.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskih, A.; Kornaś, E.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Kral, J.; Králik, I.; Kramer, F.; Kraus, I.; Kravčáková, A.; Krawutschke, T.; Krivda, M.; Krumbhorn, D.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucheriaev, Y.; Kuhn, C.; Kuijer, P. G.; Kumar, L.; Kumar, N.; Kupczak, R.; Kurashvili, P.; Kurepin, A.; Kurepin, A. N.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kutouski, M.; Kvaerno, H.; Kweon, M. J.; Kwon, Y.; La Rocca, P.; Lackner, F.; de Guevara, P. Ladrón; Lafage, V.; Lal, C.; Lara, C.; Larsen, D. T.; Laurenti, G.; Lazzeroni, C.; Le Bornec, Y.; Le Bris, N.; Lee, H.; Lee, K. S.; Lee, S. C.; Lefèvre, F.; Lenhardt, M.; Leistam, L.; Lehnert, J.; Lenti, V.; León, H.; Monzón, I. León; Vargas, H. León; Lévai, P.; Li, X.; Li, Y.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Liu, L.; Loginov, V.; Lohn, S.; Lopez, X.; López Noriega, M.; López-Ramírez, R.; López Torres, E.; Løvhøiden, G.; Lozea Feijo Soares, A.; Lu, S.; Lunardon, M.; Luparello, G.; Luquin, L.; Lutz, J.-R.; Ma, K.; Ma, R.; Madagodahettige-Don, D. M.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Makhlyueva, I.; Mal'Kevich, D.; Malaev, M.; Malagalage, K. J.; Maldonado Cervantes, I.; Malek, M.; Malkiewicz, T.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Martashvili, I.; Martinengo, P.; Martínez Hernández, M. I.; Martínez Davalos, A.; Martínez García, G.; Maruyama, Y.; Marzari Chiesa, A.; Masciocchi, S.; Masera, M.; Masetti, M.; Masoni, A.; Massacrier, L.; Mastromarco, M.; Mastroserio, A.; Matthews, Z. L.; Matyja, A.; Mayani, D.; Mazza, G.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Mendez Lorenzo, P.; Meoni, M.; Mercado Pérez, J.; Mereu, P.; Miake, Y.; Michalon, A.; Miftakhov, N.; Milano, L.; Milosevic, J.; Minafra, F.; Mischke, A.; Miśkowiec, D.; Mitu, C.; Mizoguchi, K.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Mondal, M. M.; Montaño Zetina, L.; Monteno, M.; Montes, E.; Morando, M.; Moretto, S.; Morsch, A.; Moukhanova, T.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Müller, H.; Munhoz, M. G.; Munoz, J.; Musa, L.; Musso, A.; Nandi, B. K.; Nania, R.; Nappi, E.; Navach, F.; Navin, S.; Nayak, T. K.; Nazarenko, S.; Nazarov, G.; Nedosekin, A.; Nendaz, F.; Newby, J.; Nianine, A.; Nicassio, M.; Nielsen, B. S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Nilsson, M. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Novitzky, N.; Nyatha, A.; Nygaard, C.; Nyiri, A.; Nystrand, J.; Ochirov, A.; Odyniec, G.; Oeschler, H.; Oinonen, M.; Okada, K.; Okada, Y.; Oldenburg, M.; Oleniacz, J.; Oppedisano, C.; Orsini, F.; Ortiz Velasquez, A.; Ortona, G.; Oskarsson, A.; Osmic, F.; Österman, L.; Ostrowski, P.; Otterlund, I.; Otwinowski, J.; Øvrebekk, G.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S.; Pal, S. K.; Palaha, A.; Palmeri, A.; Panse, R.; Papikyan, V.; Pappalardo, G. S.; Park, W. J.; Pastirčák, B.; Pastore, C.; Paticchio, V.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pepato, A.; Pereira, H.; Peressounko, D.; Pérez, C.; Perini, D.; Perrino, D.; Peryt, W.; Peschek, J.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A. J.; Petráček, V.; Petridis, A.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Peyré, J.; Piano, S.; Piccotti, A.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piuz, F.; Platt, R.; Płoskoń, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta Lerma, P. L. M.; Poggio, F.; Poghosyan, M. G.; Polák, K.; Polichtchouk, B.; Polozov, P.; Polyakov, V.; Pommeresch, B.; Pop, A.; Posa, F.; Pospíšil, V.; Potukuchi, B.; Pouthas, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Pulvirenti, A.; Punin, A.; Punin, V.; Putiš, M.; Putschke, J.; Quercigh, E.; Rachevski, A.; Rademakers, A.; Radomski, S.; Räihä, T. S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Ramírez Reyes, A.; Rammler, M.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rashevskaya, I.; Rath, S.; Read, K. F.; Real, J. S.; Redlich, K.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R. A.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Cahuantzi, M. Rodriguez; Røed, K.; Röhrich, D.; López, S. Román; Romita, R.; Ronchetti, F.; Rosinský, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, P.; Rubio-Montero, A. J.; Rui, R.; Rusanov, I.; Russo, G.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Saini, J.; Saiz, P.; Sakata, D.; Salgado, C. A.; Salgueiro Domingues da Silva, R.; Salur, S.; Samanta, T.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sano, M.; Sano, S.; Santo, R.; Santoro, R.; Sarkamo, J.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schindler, H.; Schmidt, C.; Schmidt, H. R.; Schossmaier, K.; Schreiner, S.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P. A.; Segato, G.; Semenov, D.; Senyukov, S.; Seo, J.; Serci, S.; Serkin, L.; Serradilla, E.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharkov, G.; Sharma, N.; Sharma, S.; Shigaki, K.; Shimomura, M.; Shtejer, K.; Sibiriak, Y.; Siciliano, M.; Sicking, E.; Siddi, E.; Siemiarczuk, T.; Silenzi, A.; Silvermyr, D.; Simili, E.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.; Snow, H.; Søgaard, C.; Soloviev, A.; Soltveit, H. K.; Soltz, R.; Sommer, W.; Son, C. W.; Son, H.; Song, M.; Soos, C.; Soramel, F.; Soyk, D.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Staley, F.; Stan, E.; Stefanek, G.; Stefanini, G.; Steinbeck, T.; Stenlund, E.; Steyn, G.; Stocco, D.; Stock, R.; Stolpovsky, P.; Strmen, P.; Suaide, A. A. P.; Subieta Vásquez, M. A.; Sugitate, T.; Suire, C.; Šumbera, M.; Susa, T.; Swoboda, D.; Symons, J.; Szanto de Toledo, A.; Szarka, I.; Szostak, A.; Szuba, M.; Tadel, M.; Tagridis, C.; Takahara, A.; Takahashi, J.; Tanabe, R.; Tapia Takaki, J. D.; Taureg, H.; Tauro, A.; Tavlet, M.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Thäder, J.; Tieulent, R.; Tlusty, D.; Toia, A.; Tolyhy, T.; Torcato de Matos, C.; Torii, H.; Torralba, G.; Toscano, L.; Tosello, F.; Tournaire, A.; Traczyk, T.; Tribedy, P.; Tröger, G.; Truesdale, D.; Trzaska, W. H.; Tsiledakis, G.; Tsilis, E.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Turvey, A.; Tveter, T. S.; Tydesjö, H.; Tywoniuk, K.; Ulery, J.; Ullaland, K.; Uras, A.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Vacchi, A.; Vala, M.; Palomo, L. Valencia; Vallero, S.; van der Kolk, N.; Vyvre, P. Vande; van Leeuwen, M.; Vannucci, L.; Vargas, A.; Varma, R.; Vasiliev, A.; Vassiliev, I.; Vasileiou, M.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vetlitskiy, I.; Vickovic, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopianov, A.; Voloshin, K.; Voloshin, S.; Volpe, G.; von Haller, B.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wagner, B.; Wagner, V.; Wallet, L.; Wan, R.; Wang, D.; Wang, Y.; Wang, Y.; Watanabe, K.; Wen, Q.; Wessels, J.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilk, A.; Wilk, G.; Williams, M. C. S.; Willis, N.; Windelband, B.; Xu, C.; Yang, C.; Yang, H.; Yasnopolskiy, S.; Yermia, F.; Yi, J.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yuan, X.; Yurevich, V.; Yushmanov, I.; Zabrodin, E.; Zagreev, B.; Zalite, A.; Zampolli, C.; Zanevsky, Y.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zbroszczyk, H.; Zelnicek, P.; Zenin, A.; Zepeda, A.; Zgura, I.; Zhalov, M.; Zhang, X.; Zhou, D.; Zhou, S.; Zhu, J.; Zichichi, A.; Zinchenko, A.; Zinovjev, G.; Zoccarato, Y.; Zycháček, V.; Zynovyev, M.

    2011-06-01

    The production of π +, π -, K+, K-, p, and overline{p} at mid-rapidity has been measured in proton-proton collisions at sqrt{s} = 900 GeV with the ALICE detector. Particle identification is performed using the specific energy loss in the inner tracking silicon detector and the time projection chamber. In addition, time-of-flight information is used to identify hadrons at higher momenta. Finally, the distinctive kink topology of the weak decay of charged kaons is used for an alternative measurement of the kaon transverse momentum ( p t) spectra. Since these various particle identification tools give the best separation capabilities over different momentum ranges, the results are combined to extract spectra from p t=100 MeV/ c to 2.5 GeV/ c. The measured spectra are further compared with QCD-inspired models which yield a poor description. The total yields and the mean p t are compared with previous measurements, and the trends as a function of collision energy are discussed.

  6. Shotgun collision-induced dissociation of peptides using a time of flight mass analyzer.

    PubMed

    Purvine, Samuel; Eppel, Jason-Thomas; Yi, Eugene C; Goodlett, David R

    2003-06-01

    Parallel collision-induced dissociation (CID) of peptides rather than serial, as is customary, results in loss of the obvious parent-fragment ion lineage available from CID on a single ion. We report proof-of-principle results suggesting the feasibility of parallel peptide CID, referred to here as shotgun CID, for protein identification when using the measured mass accuracies available from a time of flight mass analyzer and currently available search routines such as SEQUEST. Additionally, we report that parent-fragment ion lineage may be reconstructed from information encoded in the chromatographic single ion current traces of peptides.

  7. Time of flight measurement of speed of sound in air with a computer sound card

    NASA Astrophysics Data System (ADS)

    Aljalal, Abdulaziz

    2014-11-01

    A computer sound card and freely available audio editing software are used to measure accurately the speed of sound in air using the time-of-flight method. In addition to speed of sound measurement, inversion behaviour upon reflection from an open and closed end of a pipe is demonstrated. Also, it is demonstrated that the reflection at an open end of a pipe occurs slightly outside the pipe. The equipment needed is readily available to any student with access to a microphone, loudspeaker and computer.

  8. Theory and operation of a three-gate time-of-flight velocity analyzer

    NASA Technical Reports Server (NTRS)

    Martus, K. E.; Orient, O. J.; Hodges, R. R.; Chutjian, A.

    1993-01-01

    Theoretical considerations and test results are presented for a new-type velocity analyzer for incident fast neutral particles, positive ions, and negative ions. Velocity analysis is carried out by means of a pulsed, three-gate time-of-flight (TOF) technique capable of eliminating alias velocities (harmonics) to sixth order. In addition the design and operation are presented of a four-element ion lens system, with small spherical and chromatic aberrations, suitable for interfacing a large-diameter ion beam from the TOF section with a subsequent mass analyzer.

  9. Effect of electron beam pulse width on time-of-flight spectra

    NASA Technical Reports Server (NTRS)

    Misakian, M.; Mumma, M. J.

    1974-01-01

    A simple but useful formula describing the effect of electron gun pulse width on the time of flight (TOF) spectra measured in translational spectroscopy experiments is developed. An approximately monoenergetic pulsed electrostatically focused electron beam traverses a scattering cell filled with a Maxwellian gas. Inelastic electron collisions with the gas produce metastable particles, ions, scattered electrons, and photons which then pass through a collimating slit system at right angles to the electron beam. TOF techniques are used to separate the photon signal from the metastable particle signal and to measure the TOF distribution of the metastable species.

  10. Effect of trapped ions in a gated time-of-flight apparatus

    NASA Technical Reports Server (NTRS)

    Martus, K. E.; Orient, O. J.; Chutjian, A.

    1993-01-01

    A three-mesh gate is used in a time-of-flight (TOF) apparatus to analyze the velocity of positive ions. Test results and a theoretical description are presented of an effect arising from trapping ions between meshes of a two-gate TOF velocity analyzer. The entrapped ions produce a side peak in the TOF spectra corresponding to faster ions. The onset and relative height of the side peak is dependent on the gating voltage and risetime of the pulsing electronics, while the relative intensity depends upon the velocity being sampled and the ratio of the gate width to duration.

  11. TIME-OF-FLIGHT MASS MEASUREMENTS AND THEIR IMPORTANCE FOR NUCLEAR ASTROPHYSICS

    SciTech Connect

    Matos, M.; Shapira, Dan

    2009-01-01

    Atomic masses play an important role in nuclear astrophysics. The lack of experimental values for nuclides of interest has triggered a rapid development of new mass measurement devices around the world, including Time-of-Flight (TOF) mass measurements offering an access to the most exotic nuclides. Recently, the TOF-B rho technique that includes a position measurement for magnetic rigidity correction has been implemented at the NSCL. An experiment with a similar TOF-B rho technique is approved and planned at the next generation radioactive beam facility (RIBF) at RIKEN.

  12. Electron pair emission detected by time-of-flight spectrometers: Recent progress

    SciTech Connect

    Huth, Michael; Schumann, Frank O.; Chiang, Cheng-Tien; Trützschler, Andreas; Kirschner, Jürgen; Widdra, Wolf

    2014-02-10

    We present results for electron coincidence spectroscopy using two time-of-flight (ToF) spectrometers. Excited by electron impact, the energy and momentum distribution of electron pairs emitted from the Cu(111) surface are resolved and a spectral feature related to the Shockley surface state is identified. By combining the two ToF spectrometers with a high-order harmonic generation light source, we demonstrate double photoemission spectroscopy in the laboratory that required synchrotron radiation in the past. Utilizing this setup, we report results for (γ,2e) on NiO(001) on Ag(001) excited with light at 30 eV photon energy.

  13. Time-of-flight velocity analysis of atomic and molecular beams

    NASA Technical Reports Server (NTRS)

    Hagena, O. F.; Varma, A. K.

    1968-01-01

    Conditions required for resolving a given beam speed distribution were evaluated by calculating the time-of-flight (TOF) signal for a finite open time of the beam shutter. Design criteria for a beam chopper and detection system are discussed in terms of the resolution, the range of speeds to be measured, and the optimum signal to noise ratio. A TOF system for detection of high intensity molecular beams with large speed ratios, as well as for low intensity scattered beams, is described. Experimental results are presented.

  14. Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments

    DOE PAGES

    Hatarik, R.; Sayre, D. B.; Caggiano, J. A.; ...

    2015-11-12

    For a long time, neutron time-of-flight diagnostics been used to characterize the neutron spectrum produced by inertial confinement fusion experiments. The primary diagnostic goals are to extract the d+t→n+α (DT) and d+d→n+³He (DD) neutron yields and peak widths, and the amount DT scattering relative to its unscattered yield, which is also known as the down-scatter ratio (DSR). These quantities are used to infer yield weighted plasma conditions, such as ion temperature (Tion) and cold fuel areal density. We explain such novel methodologies used to determine neutron yield, apparent Tion and DSR.

  15. Stopping power measurements with the Time-of-Flight (ToF) technique

    DOE PAGES

    Fontana, Cristiano L.; Chen, Chien-Hung; Crespillo, Miguel L.; ...

    2015-11-10

    In our review of measurements of the stopping power of ions in matter is presented along with new measurements of the stopping powers of O, Si, Ti, and Au ions in self-supporting thin foils of SiO2, Nb2O5, and Ta2O5. Moreover, a Time-of-Flight system at the Ion Beam Materials Laboratory at the University of Tennessee, Knoxville, was used in transmission geometry in order to reduce experimental uncertainties. Finally, the resulting stopping powers show good precision and accuracy and corroborate previously quoted values in the literature. New stopping data are determined.

  16. The sTOF, a Favorable Geometry for a Time-of-Flight Analyzer

    NASA Astrophysics Data System (ADS)

    Murphy, Daniel M.

    2017-02-01

    A new geometry for the flight region in a time-of-flight mass spectrometer is presented. It consists of two opposing electrostatic sectors of about 255° each and straight sections with a length appropriate to the turns. The resulting geometry folds into a compact space. The first-order aberrations for position, angle, and energy are all zero. The transverse focusing properties are also excellent. For an energetic, high-divergence ion source such as laser ablation, the sTOF has higher resolution and ion transmission than a reflectron of similar physical size.

  17. Note: A novel dual-channel time-of-flight mass spectrometer for photoelectron imaging spectroscopy

    SciTech Connect

    Qin Zhengbo; Wu Xia; Tang Zichao

    2013-06-15

    A novel dual-channel time-of-flight mass spectrometer (D-TOFMS) has been designed to select anions in the photoelectron imaging measurements. In this instrument, the radiation laser can be triggered precisely to overlap with the selected ion cloud at the first-order space focusing plane. Compared with that of the conventional single channel TOFMS, the in situ mass selection performance of D-TOFMS is significantly improved. Preliminary experiment results are presented for the mass-selected photodetachment spectrum of F{sup -} to demonstrate the capability of the instrument.

  18. A Low-cost, Lightweight, and Miniaturized Time-of-flight Mass Spectrometer (TOFMS)

    NASA Technical Reports Server (NTRS)

    Srivastava, S. K.

    1993-01-01

    Time-of-flight mass spectrometers (TOFMS) are commonly used for mass analysis and for the measurement of energy distributions of charged particles. For achieving high mass and energy resolution these instruments generally comprise long flight tubes, often as long as a few meters. This necessitates high voltages and a very clean environment. These requirements make them bulky and heavy. We have developed an instrument and calibration techniques that are based on the design principles of TOFMS. However, instead of one long flight tube it consists of a series of cylindrical electrostatic lenses that confine ions under study along the axis of the flight tube.

  19. Time-of-Flight Mass Measurements and Their Importance for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Matoš, M.; Estrade, A.; Amthor, A. M.; Bazin, D.; Becerril, A.; Elliot, T.; Famiano, M.; Gade, A.; Galaviz, D.; Lorusso, G.; Pereira, J.; Portillo, M.; Rogers, A.; Schatz, H.; Shapira, D.; Smith, E.; Stolz, A.; Wallace, M.

    2009-03-01

    Atomic masses play an important role in nuclear astrophysics. The lack of experimental values for nuclides of interest has triggered a rapid development of new mass measurement devices around the world, including Time-of-Flight (TOF) mass measurements offering an access to the most exotic nuclides. Recently, the TOF-Brho technique that includes a position measurement for magnetic rigidity correction has been implemented at the NSCL. An experiment with a similar TOF-Brho technique is approved and planned at the next generation radioactive beam facility (RIBF) at RIKEN.

  20. Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments

    SciTech Connect

    Hatarik, R.; Sayre, D. B.; Caggiano, J. A.; Phillips, T.; Eckart, M. J.; Bond, E. J.; Cerjan, C.; Grim, G. P.; Hartouni, E. P.; Knauer, J. P.; Mcnaney, J. M.; Munro, D. H.

    2015-11-12

    For a long time, neutron time-of-flight diagnostics been used to characterize the neutron spectrum produced by inertial confinement fusion experiments. The primary diagnostic goals are to extract the d+t→n+α (DT) and d+d→n+³He (DD) neutron yields and peak widths, and the amount DT scattering relative to its unscattered yield, which is also known as the down-scatter ratio (DSR). These quantities are used to infer yield weighted plasma conditions, such as ion temperature (Tion) and cold fuel areal density. We explain such novel methodologies used to determine neutron yield, apparent Tion and DSR.

  1. Imaging time-of-flight secondary ion mass spectrometry of solid-phase peptide syntheses.

    PubMed

    Aubagnac, J L; Enjalbal, C; Drouot, C; Combarieu, R; Martinez, J

    1999-07-01

    Imaging time-of-flight secondary ion mass spectrometry (TOF-SIMS) of solid-phase peptide syntheses carried out by the Merrifield and Sheppard strategies is described. Mixtures of resin beads mixed at random from batch syntheses or obtained in combinatorial chemistry by the mix and split technique, where each bead is functionalized by a unique peptide, were analyzed directly without any chemical cleavage of the growing chains to assess the nature of the growing structure on any bead of the mixture without its isolation.

  2. Resolving multipath interference in time-of-flight imaging via modulation frequency diversity and sparse regularization.

    PubMed

    Bhandari, Ayush; Kadambi, Achuta; Whyte, Refael; Barsi, Christopher; Feigin, Micha; Dorrington, Adrian; Raskar, Ramesh

    2014-03-15

    Time-of-flight (ToF) cameras calculate depth maps by reconstructing phase shifts of amplitude-modulated signals. For broad illumination of transparent objects, reflections from multiple scene points can illuminate a given pixel, giving rise to an erroneous depth map. We report here a sparsity-regularized solution that separates K interfering components using multiple modulation frequency measurements. The method maps ToF imaging to the general framework of spectral estimation theory and has applications in improving depth profiles and exploiting multiple scattering.

  3. Quantum time-of-flight measurements: Kicked clock versus continuous clock

    SciTech Connect

    Alonso, Daniel; Sala Mayato, R.; Muga, J.G.

    2003-03-01

    The measurement of time durations or instants of occurrence of events has been frequently modeled 'operationally' by coupling the system of interest to a ''clock.'' According to several of these models, the operational approach is limited at low energies because the perturbation of the clock does not allow to reproduce accurately the corresponding ideal time quantity, defined for the system in isolation. We show that, for a time-of-flight measurement model that can be set to measure dwell or arrival times, these limitations may be overcome by extending the range of energies where the clock works properly using pulsed couplings rather than continuous ones.

  4. Solid Phase Microextraction and Miniature Time-of-Flight Mass Spectrometer

    SciTech Connect

    Hiller, j.m.

    1999-01-26

    A miniature mass spectrometer, based on the time-of-flight principle, has been developed for the detection of chemical warfare agent precursor molecules. The instrument, with minor modifications, could fulfill many of the needs for sensing organic molecules in various Defense Programs, including Enhanced Surveillance. The basic footprint of the instrument is about that of a lunch box. The instrument has a mass range to about 300, has parts-per-trillion detection limits, and can return spectra in less than a second. The instrument can also detect permanent gases and is especially sensitive to hydrogen. In volume, the device could be manufactured for under $5000.

  5. Time-of-flight compressed-sensing ultrafast photography for encrypted three-dimensional dynamic imaging

    NASA Astrophysics Data System (ADS)

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

    2016-02-01

    We applied compressed ultrafast photography (CUP), a computational imaging technique, to acquire three-dimensional (3D) images. The approach unites image encryption, compression, and acquisition in a single measurement, thereby allowing efficient and secure data transmission. By leveraging the time-of-flight (ToF) information of pulsed light reflected by the object, we can reconstruct a volumetric image (150 mm×150 mm×1050 mm, x × y × z) from a single camera snapshot. Furthermore, we demonstrated high-speed 3D videography of a moving object at 75 frames per second using the ToF-CUP camera.

  6. Waveform-Sampling Electronics for a Whole-Body Time-of-Flight PET Scanner

    PubMed Central

    Ashmanskas, W. J.; LeGeyt, B. C.; Newcomer, F. M.; Panetta, J. V.; Ryan, W. A.; Van Berg, R.; Wiener, R. I.; Karp Fellow, J. S.

    2014-01-01

    Waveform sampling is an appealing technique for instruments requiring precision time and pulse-height measurements. Sampling each PMT waveform at oscilloscope-like rates of several gigasamples per second enables one to process PMT signals digitally, which in turn makes it straightforward to optimize timing resolution and amplitude (energy and position) resolution in response to calibration effects, pile-up effects, and other systematic sources of waveform variation. We describe a system design and preliminary implementation that neatly maps waveform-sampling technology onto the LaPET prototype whole-body time-of-flight PET scanner that serves as the platform for testing this new technology. PMID:25484379

  7. Interaction of solar wind ions with thin carbon foils: Calibration of time-of-flight spectrometers

    NASA Astrophysics Data System (ADS)

    Gonin, M.; Buergi, Alfred; Oetliker, M.; Bochsler, P.

    1992-11-01

    With the KAFKA (German acronym for carbon foils collisions analyzer) experiment, charge exchange, energy loss and angular scattering of solar wind ions in thin (1 to 10 microg/sq cm) carbon foils, are studied. Such foils are extensively used in time of flight mass spectrometry. So far, the properties of H, He, B, C, N, O, F, Ne, Na, Mg, Al, Si, S, Cl, Ar, K, Ti, Fe, and Ni and in the 0.5 to 5 keV/u energy range have been investigated.

  8. Time-of-flight detection of ultra-cold atoms using resonant frequency modulation imaging.

    PubMed

    Hardman, K S; Wigley, P B; Everitt, P J; Manju, P; Kuhn, C C N; Robins, N P

    2016-06-01

    Resonant frequency modulation imaging is used to detect free falling ultra-cold atoms. A theoretical comparison of fluorescence imaging (FI) and frequency modulation imaging (FMI) is made, indicating that for low optical depth clouds, FMI accomplished a higher signal-to-noise ratio under conditions necessary for a 200 μm spatially resolved atom interferometer. A 750 ms time-of-flight measurement reveals near atom shot-noise limited number measurements of 2×106 Bose-condensed Rb87 atoms. The detection system is applied to high precision spinor BEC based atom interferometer.

  9. Delayed extraction time-of-flight mass spectrometer with electron impact for PAH studies

    NASA Astrophysics Data System (ADS)

    Najeeb, P. K.; Kadhane, U.

    2017-03-01

    A time-of-flight (ToF) mass spectrometer with a pulsed electron beam as well as pulsed extraction of the recoil ions, with variable delay is reported. The effectiveness of this technique is highlighted by studying the statistical decay of mono-cations over microsecond time scales. Various details of the design and operation are discussed in the context of electron impact ionization and fragmentation of naphthalene (C10H8). The temporal behavior of acetylene (C2H2) and diacetylene (C4H2) loss is observed and compared with the associated Arrhenius decay constant, internal energy and plasmon excitation energy.

  10. In situ analysis of thin film deposition processes using time-of-flight (TOF) ion beam analysis methods

    SciTech Connect

    Im, J. |; Krauss, A.R.; Gruen, D.M.; Lin, Y.; Schultz, J.A.; Auciello, O.H.; Chang, R.P.H.

    1995-05-01

    Non-destructive, in situ methods for characterization of thin film growth phenomena is key to understand thin film growth processes and to develop more reliable deposition procedures, especially for complex layered structures involving multi-phase materials. However, surface characterization methods that use either electrons (e.g. AES or XPS) or low energy ions (SIMS) require an UHV environment and utilize instrumentation which obstructs line of sight access to the substrate and are therefore incompatible with line of sight deposition methods and thin film deposition processes which introduce gas, either part of the deposition or in order to produce the desired phase. We have developed a means of differentially pumping both the ion beam source and detectors of a TOF ion beam surface analysis spectrometer that does not interfere with the deposition process and permits compositional and structural analysis of the growing film in the present system, at pressures up to several mTorr. Higher pressures are feasible with modified source-detector geometry. In order to quantify the sensitivity of Ion Scattering Spectroscopy (ISS) and Direct Recoil Spectroscopy (DRS), we have measured the signal intensity for stabilized clean metals in a variety of gas environments as a function of the ambient gas species and pressure, and ion beam species and kinetic energy. Results are interpreted in terms of collision cross sections which are compared with known gas phase scattering data and provide an apriori basis for the evaluation of time-of-flight ion scattering and recoil spectroscopies (ToF-ISARS) for various industrial processing environments which involve both inert and reactive cases. The cross section data for primary ion-gas molecule and recoiled atom-gas molecule interactions are also provided. from which the maximum operating pressure in any experimental configuration can be obtained.

  11. Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    SciTech Connect

    Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; Di Fulvio, A.; Clarke, S. D.; Pozzi, S. A.; Febbraro, M.

    2016-03-02

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. x 3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and E1315) this scintillator can provide good pulse shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene -based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition E1301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light -response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective ( x 10 to x 100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. Here, as we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse -selected beam (as needed for time-of-flight) is not available.

  12. Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    DOE PAGES

    Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; ...

    2016-03-02

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. x 3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and E1315) this scintillator can provide good pulse shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene -based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is muchmore » safer for many applications. In addition E1301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light -response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective ( x 10 to x 100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. Here, as we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse -selected beam (as needed for time-of-flight) is not available.« less

  13. Deuterated-xylene (xylene-d10; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

    NASA Astrophysics Data System (ADS)

    Becchetti, F. D.; Raymond, R. S.; Torres-Isea, R. O.; Di Fulvio, A.; Clarke, S. D.; Pozzi, S. A.; Febbraro, M.

    2016-06-01

    In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. ×3 in. deuterated-xylene organic liquid scintillator (C8D10; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C6D6; NE230, BC537, and EJ315) this scintillator can provide good pulse-shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene-based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition EJ301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light-response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective (×10 to ×100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. As we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse-selected beam (as needed for time-of-flight) is not available.

  14. Overview of recent ALICE results

    NASA Astrophysics Data System (ADS)

    Lakomov, Igor

    2016-10-01

    ALICE is one of the four largest LHC experiments. It is dedicated to the study of the properties of the deconfined state of matter formed at large energy densities in heavy-ion collisions — the Quark-Gluon Plasma. The ALICE Collaboration also participated in the pp and p-Pb data-taking periods at the LHC. An overview of recent ALICE results is presented for three collision systems: pp, p-Pb and Pb-Pb.

  15. Time-of-Flight Polarized Neutron Reflectometry on PLATYPUS: Status and Future Developments

    NASA Astrophysics Data System (ADS)

    Saerbeck, T.; Cortie, D. L.; Brück, S.; Bertinshaw, J.; Holt, S. A.; Nelson, A.; James, M.; Lee, W. T.; Klose, F.

    Time-of-flight (ToF) polarized neutron reflectometry enables the detailed investigation of depth-resolved magnetic structures in thin film and multilayer magnetic systems. The general advantage of the time-of-flight mode of operation over monochromatic instruments is a decoupling of spectral shape and polarization of the neutron beam with variable resolution. Thus, a wide Q-range can be investigated using a single angle of incidence, with resolution and flux well-adjusted to the experimental requirement. Our paper reviews the current status of the polarization equipment of the ToF reflectometer PLATYPUS and presents first results obtained on stratified Ni80Fe20/α-Fe2O3 films, revealing the distribution of magnetic moments in an exchange bias system. An outlook on the future development of the PLATYPUS polarization system towards the implementation of a polarized 3He cell is presented and discussed with respect to the efficiency and high Q-coverage up to 1 Å-1 and 0.15 Å-1 in the vertical and lateral momentum transfer, respectively.

  16. The multipurpose time-of-flight neutron reflectometer “Platypus” at Australia's OPAL reactor

    NASA Astrophysics Data System (ADS)

    James, M.; Nelson, A.; Holt, S. A.; Saerbeck, T.; Hamilton, W. A.; Klose, F.

    2011-03-01

    In this manuscript we describe the major components of the Platypus time-of-flight neutron reflectometer at the 20 MW OPAL reactor in Sydney, Australia. Platypus is a multipurpose spectrometer for the characterisation of solid thin films, materials adsorbed at the solid-liquid interface and free-liquid surfaces. It also has the capacity to study magnetic thin films using spin-polarised neutrons. Platypus utilises a white neutron beam ( λ=2-20 Å) that is pulsed using boron-coated disc chopper pairs; thus providing the capacity to tailor the wavelength resolution of the pulses to suit the system under investigation. Supermirror optical components are used to focus, deflect or spin-polarise the broad bandwidth neutron beams, and typical incident spectra are presented for each configuration. A series of neutron reflectivity datasets are presented, indicating the quality and flexibility of this spectrometer. Minimum reflectivity values of <10 -7 are observed; while maximum thickness values of 325 nm have been measured for single-component films and 483 nm for a multilayer system. Off-specular measurements have also been made to investigate in-plane features as opposed to those normal to the sample surface. Finally, the first published studies conducted using the Platypus time-of-flight neutron reflectometer are presented.

  17. Slow light and chromatic temporal dispersion in photonic crystal waveguides using femtosecond time of flight.

    PubMed

    Finlayson, C E; Cattaneo, F; Perney, N M B; Baumberg, J J; Netti, M C; Zoorob, M E; Charlton, M D B; Parker, G J

    2006-01-01

    We report time-of-flight experiments on photonic-crystal waveguide structures using optical Kerr gating of a femtosecond white-light supercontinuum. These photonic-crystal structures, based on engineered silicon-nitride slab waveguides, possess broadband low-loss guiding properties, allowing the group velocity dispersion of optical pulses to be directly tracked as a function of wavelength. This dispersion is shown to be radically disrupted by the spectral band gaps associated with the photonic-crystal periodicity. Increased time-of-flight effects, or "slowed light," are clearly observed at the edges of band gaps in agreement with two-dimensional plane-wave theoretical models of group velocity dispersion. A universal model for slow light in such photonic crystals is proposed, which shows that slow light is controlled predominantly by the detuning from, and the size of, the photonic band gaps. Slowed light observed up to time delays of approximately 1 ps, corresponds to anomalous dispersion of approximately 3.5 ps/nm per mm of the photonic crystal structure. From the decreasing intensity of time-gated slow light as a function of time delay, we estimate the characteristic losses of modes which are guided in the spectral proximity of the photonic band gaps.

  18. TOFPET 2: A high-performance circuit for PET time-of-flight

    NASA Astrophysics Data System (ADS)

    Di Francesco, Agostino; Bugalho, Ricardo; Oliveira, Luis; Rivetti, Angelo; Rolo, Manuel; Silva, Jose C.; Varela, Joao

    2016-07-01

    We present a readout and digitization ASIC featuring low-noise and low-power for time-of flight (TOF) applications using SiPMs. The circuit is designed in standard CMOS 110 nm technology, has 64 independent channels and is optimized for time-of-flight measurement in Positron Emission Tomography (TOF-PET). The input amplifier is a low impedance current conveyor based on a regulated common-gate topology. Each channel has quad-buffered analogue interpolation TDCs (time binning 20 ps) and charge integration ADCs with linear response at full scale (1500 pC). The signal amplitude can also be derived from the measurement of time-over-threshold (ToT). Simulation results show that for a single photo-electron signal with charge 200 (550) fC generated by a SiPM with (320 pF) capacitance the circuit has 24 (30) dB SNR, 75 (39) ps r.m.s. resolution, and 4 (8) mW power consumption. The event rate is 600 kHz per channel, with up to 2 MHz dark counts rejection.

  19. TOF plotter—a program to perform routine analysis time-of-flight mass spectral data

    NASA Astrophysics Data System (ADS)

    Knippel, Brad C.; Padgett, Clifford W.; Marcus, R. Kenneth

    2004-03-01

    The main article discusses the operation and application of the program to mass spectral data files. This laboratory has recently reported the construction and characterization of a linear time-of-flight mass spectrometer (ToF-MS) utilizing a radio frequency glow discharge ionization source. Data acquisition and analysis was performed using a digital oscilloscope and Microsoft Excel, respectively. Presently, no software package is available that is specifically designed for time-of-flight mass spectral analysis that is not instrument dependent. While spreadsheet applications such as Excel offer tremendous utility, they can be cumbersome when repeatedly performing tasks which are too complex or too user intensive for macros to be viable. To address this situation and make data analysis a faster, simpler task, our laboratory has developed a Microsoft Windows-based software program coded in Microsoft Visual Basic. This program enables the user to rapidly perform routine data analysis tasks such as mass calibration, plotting and smoothing on x- y data sets. In addition to a suite of tools for data analysis, a number of calculators are built into the software to simplify routine calculations pertaining to linear ToF-MS. These include mass resolution, ion kinetic energy and single peak identification calculators. A detailed description of the software and its associated functions is presented followed by a characterization of its performance in the analysis of several representative ToF-MS spectra obtained from different GD-ToF-MS systems.

  20. Identification of rolling circulating tumor cells using photoacoustic time-of-flight method

    NASA Astrophysics Data System (ADS)

    Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Galanzha, Ekaterina I.; Zharov, Vladimir P.

    2013-03-01

    Existing optical techniques for in vivo measurement of blood flow velocity are not quite applicable for determination of velocity of individual cells or nanoparticles. A time-of-flight photoacoustic (PA) technique can solve this problem by measuring the transient PA signal width, which is related to the cell velocity passing the laser beam. This technique was demonstrated in vivo using an animal (mouse) model by estimating the velocity of nanoparticles, and red and white blood cells labeled with conjugated gold nanorods (GNRs) in the bloodstream. Here we describe the features and the parameters of novel modifications to the PA time-of-flight method and its new application for real-time monitoring of circulating tumor cells (CTCs), such as B16F10 melanoma. This method provided, for the first time, identification of rolling CTCs in analogy to rolling white blood cells and CTC aggregates. Specifically, monitoring of PA signal widths from CTCs in mouse ear microvessels revealed double maxima in peak-width histograms associated with the fast moving portion of CTCs in central flow and slowly rolling CTCs in analogy to white blood cells. We also developed a two-parameter plot representing PA peak amplitude and peak widths. This method allowed identification of fast-moving individual CTCs, CTC aggregates, and rolling CTCs. The discovery of rolling CTCs in relatively large blood vessels indicates a higher probability of CTC extravasations, further increasing the possibility of metastasis through rolling mechanism in addition to mechanical capturing of CTCs in small vessels.

  1. Evaluating the capability of time-of-flight cameras for accurately imaging a cyclically loaded beam

    NASA Astrophysics Data System (ADS)

    Lahamy, Hervé; Lichti, Derek; El-Badry, Mamdouh; Qi, Xiaojuan; Detchev, Ivan; Steward, Jeremy; Moravvej, Mohammad

    2015-05-01

    Time-of-flight cameras are used for diverse applications ranging from human-machine interfaces and gaming to robotics and earth topography. This paper aims at evaluating the capability of the Mesa Imaging SR4000 and the Microsoft Kinect 2.0 time-of-flight cameras for accurately imaging the top surface of a concrete beam subjected to fatigue loading in laboratory conditions. Whereas previous work has demonstrated the success of such sensors for measuring the response at point locations, the aim here is to measure the entire beam surface in support of the overall objective of evaluating the effectiveness of concrete beam reinforcement with steel fibre reinforced polymer sheets. After applying corrections for lens distortions to the data and differencing images over time to remove systematic errors due to internal scattering, the periodic deflections experienced by the beam have been estimated for the entire top surface of the beam and at witness plates attached. The results have been assessed by comparison with measurements from highly-accurate laser displacement transducers. This study concludes that both the Microsoft Kinect 2.0 and the Mesa Imaging SR4000s are capable of sensing a moving surface with sub-millimeter accuracy once the image distortions have been modeled and removed.

  2. Breath Analysis Using a Time-of-Flight Camera and Pressure Belts.

    PubMed

    Zalud, Ludek; Kotova, Marketa; Kocmanová, Petra; Dobsak, Petr; Kolarova, Jana

    2016-06-01

    The proper way of breathing is important for everyone. Healthy people often do not follow respiration until breathing problems start-during stress or during sport activity in physiological cases. More serious cases are stroke, injury, or surgery of the chest and others. So, learning to breathe correctly and/or breathing diagnosis is considerable for many reasons. Two novel methods of breath analysis suitable for diagnostics and rehabilitation are presented. The first technique utilizes pressure belts fastened to the patient's belly and chest, and the second method relies on a SwissRanger SR-4000 time-of-flight camera. The measurement principles are described together with the advantages and disadvantages of the applied techniques. The SwissRanger camera depth calibration is proposed to facilitate better results during the breath analysis. The methods are tested on a group of students to provide a comparison of their individual performances. As it was demonstrated, presented methods proved to work reliably. The method based on time-of-flight camera seems to be more suitable for diagnosis, while the method based on pressure belts is more suitable for rehabilitation and biofeedback applications.

  3. Structural measurements on several alamethicin peptides by the time-of-flight correlation technique

    NASA Astrophysics Data System (ADS)

    Poppe-Schriemer, N.; Ens, W.; O'Neil, J. D.; Spicer, V.; Standing, K. G.; Westmore, J. B.; Yee, A. A.

    1995-05-01

    Time-of-flight correlation methods have been used to determine the primary structure of the major component in a nonstandard preparation of alamethicins, and to give some sequence information about minor components. The peptide (MW [approximate] 2000 u) is blocked at the N terminus with an acetyl group and has a primary alcohol rather than a carboxyl group at the C terminus, so the usual wet chemical sequencing methods cannot be applied. Upon bombardment with 25 keVI- ions, the peptide, deposited on the surface of a solid target, produces both molecular ions and prompt fragment ions (i.e. ions formed at or very near the surface of the target). After acceleration, these ions may undergo metastable decay as they pass along the flight tube of a reflecting time-of-flight mass spectrometer. Measurement of the correlations between the neutral and charged daughters from these decompositions determines the decay pattern of each ion, which in turn yields definitive information about the sequence of the original peptide. All events are recorded on magnetic tape and analyzed off-line, so a single run on the spectrometer provides information on the decay of every ion produced at the target, i.e. information similar to that obtainable from a complete set of daughter ion scans on a multiple sector or triple quadrupole instrument.

  4. Pharmaceutical metabolite profiling using quadrupole/ion mobility spectrometry/time-of-flight mass spectrometry.

    PubMed

    Chan, Eric C Y; New, Lee Sun; Yap, Chun Wei; Goh, Lin Tang

    2009-02-01

    The use of hybrid quadrupole ion mobility spectrometry time-of-flight mass spectrometry (Q/IMS/TOFMS) in the metabolite profiling of leflunomide (LEF) and acetaminophen (APAP) is presented. The IMS drift times (T(d)) of the drugs and their metabolites were determined in the IMS/TOFMS experiments and correlated with their exact monoisotopic masses and other in silico generated structural properties, such as connolly molecular area (CMA), connolly solvent-excluded volume (CSEV), principal moments of inertia along the X, Y and Z Cartesian coordinates (MI-X, MI-Y and MI-Z), inverse mobility and collision cross-section (CCS). The correlation of T(d) with these parameters is presented and discussed. IMS/TOF tandem mass spectrometry experiments (MS(2) and MS(3)) were successfully performed on the N-acetyl-p-benzoquinoneimine glutathione (NAPQI-GSH) adduct derived from the in vitro microsomal metabolism of APAP. As comparison, similar experiments were also performed using hybrid triple quadrupole linear ion trap mass spectrometry (QTRAPMS) and quadrupole time-of-flight mass spectrometry (QTOFMS). The abilities to resolve the product ions of the metabolite within the drift tube and fragment the ion mobility resolved product ions in the transfer travelling wave-enabled stacked ring ion guide (TWIG) demonstrated the potential applicability of the Q/IMS/TOFMS technique in pharmaceutical metabolite profiling.

  5. Tagging of Isobars Using Energy Loss and Time-of-flight Measurements

    SciTech Connect

    Shapira, D.

    2001-11-02

    The technique for tagging isobars in a mixed beam by measuring energy loss by time-of-flight has been tested. With this method, isobar separation should improve by allowing more energy loss (thicker absorber), but only if one can control absorber homogeneity. Measurements of beam energy toss and energy spread obtained under such conditions were shown to be close to predicted values using both collisional and charge exchange contributions to energy straggling. The calculation of energy straggling allows us to study the efficacy of this method for isobar separation when applied to different mass ranges and beam energies. Separation in a most difficult case, an analyzed beam of A = 132 isobars at energies near 3 MeV/A has been demonstrated. The time-of-flight information can be added on line as an additional tag to the data stream for events of interest. Such event by event tagging enables one to study the effect of differences in isobaric mixture in the beam on the reaction outcome even when isobar separation is not complete.

  6. Electric field measurement in the ionosphere using the time-of-flight technique

    SciTech Connect

    Nakamura, Masato; Hayakawa, Hajime; Tsuruda, Koichiro )

    1989-05-01

    The first successful electric field measurement in the ionosphere using the time-of-flight technique with a lithium ion beam was carried out on a S-520 sounding rocket launched from Kagoshima Space Center, Japan on January 15, 1987. The purpose of this experiment was to prove the validity of the time-of-flight technique when it is applied to the measurement of the dc electric field in the ionosphere. A time-coded ion beam was ejected from the rocket in the direction perpendicular to the Earth's magnetic field. The beam returned to the rocket twice per rocket spin when the initial beam direction was nearly perpendicular to the electric field. The electric field and the magnetic field were derived from the travel time of these return lithium ions. The accuracy of the electric field determination was {plus minus} 0.3 mV/m. The direction of the electric field was obtained from the direction of the returning ion beam after about one ion gyration. The main constituent of the measured electric field was a V {times} B field due to the rocket motion across the geomagnetic field. The ambient field was less than 1 mV/m. The magnetic field was measured with an accuracy of {plus minus} 2.7 nT in this experiment.

  7. Recent Advances and Future Advances in Time-of-Flight PET

    PubMed Central

    Moses, William W.

    2007-01-01

    Simple theory predicts that the statistical noise variance in PET can be reduced by an order of magnitude by using time-of-flight (TOF) information. This reduction can be obtained by improving the coincidence timing resolution, and so would be achievable in clinical, whole body studies using with PET systems that differ little from existing cameras. The potential impact of this development is large, especially for oncology studies in large patients, where it is sorely needed. TOF PET was extensively studied in the 1980’s but died away in the 1990’s, as it was impossible to reliably achieve sufficient timing resolution without sacrificing other important PET performance aspects, such as spatial resolution and efficiency. Recent advances in technology (scintillators, photodetectors, and high speed electronics) have renewed interest in TOF PET, which is experiencing a rebirth. However, there is still much to be done, both in instrumentation development and evaluating the true benefits of TOF in modern clinical PET. This paper looks at what has been accomplished and what needs to be done before time-of-flight PET can reach its full potential. PMID:18836513

  8. A constant-momentum/energy-selector time-of-flight mass spectrometer.

    PubMed

    Santacruz, C P; Håkansson, P; Barofsky, D F; Piyadasa, C K G

    2007-01-01

    A matrix assisted laser desorption/ionization time-of-flight mass spectrometer has been built with an ion source that can be operated in either constant-energy or constant-momentum acceleration modes. A decreasing electric field distribution in the ion-accelerating region makes it possible to direct ions onto a space-focal plane in either modes of operation. Ions produced in the constant-momentum mode have velocities and, thus, flight times that are linearly dependent on mass and kinetic energies that are inversely dependent on mass. The linear mass dispersion doubles mass resolving power of ions accelerated with space-focusing conditions in constant-momentum mode. The mass-dependent kinetic energy is exploited to disperse ions according to mass in a simple kinetic energy filter constructed from two closely spaced, oblique ion reflectors. Focusing velocity of ions of the same mass can substantially improve ion selection for subsequent post source decay or tandem time-of-flight analyses.

  9. Time-frequency energy density precipitation method for time-of-flight extraction of narrowband Lamb wave detection signals.

    PubMed

    Zhang, Y; Huang, S L; Wang, S; Zhao, W

    2016-05-01

    The time-of-flight of the Lamb wave provides an important basis for defect evaluation in metal plates and is the input signal for Lamb wave tomographic imaging. However, the time-of-flight can be difficult to acquire because of the Lamb wave dispersion characteristics. This work proposes a time-frequency energy density precipitation method to accurately extract the time-of-flight of narrowband Lamb wave detection signals in metal plates. In the proposed method, a discrete short-time Fourier transform is performed on the narrowband Lamb wave detection signals to obtain the corresponding discrete time-frequency energy density distribution. The energy density values at the center frequency for all discrete time points are then calculated by linear interpolation. Next, the time-domain energy density curve focused on that center frequency is precipitated by least squares fitting of the calculated energy density values. Finally, the peak times of the energy density curve obtained relative to the initial pulse signal are extracted as the time-of-flight for the narrowband Lamb wave detection signals. An experimental platform is established for time-of-flight extraction of narrowband Lamb wave detection signals, and sensitivity analysis of the proposed time-frequency energy density precipitation method is performed in terms of propagation distance, dispersion characteristics, center frequency, and plate thickness. For comparison, the widely used Hilbert-Huang transform method is also implemented for time-of-flight extraction. The results show that the time-frequency energy density precipitation method can accurately extract the time-of-flight with relative error of <1% and thus can act as a universal time-of-flight extraction method for narrowband Lamb wave detection signals.

  10. Time-frequency energy density precipitation method for time-of-flight extraction of narrowband Lamb wave detection signals

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Huang, S. L.; Wang, S.; Zhao, W.

    2016-05-01

    The time-of-flight of the Lamb wave provides an important basis for defect evaluation in metal plates and is the input signal for Lamb wave tomographic imaging. However, the time-of-flight can be difficult to acquire because of the Lamb wave dispersion characteristics. This work proposes a time-frequency energy density precipitation method to accurately extract the time-of-flight of narrowband Lamb wave detection signals in metal plates. In the proposed method, a discrete short-time Fourier transform is performed on the narrowband Lamb wave detection signals to obtain the corresponding discrete time-frequency energy density distribution. The energy density values at the center frequency for all discrete time points are then calculated by linear interpolation. Next, the time-domain energy density curve focused on that center frequency is precipitated by least squares fitting of the calculated energy density values. Finally, the peak times of the energy density curve obtained relative to the initial pulse signal are extracted as the time-of-flight for the narrowband Lamb wave detection signals. An experimental platform is established for time-of-flight extraction of narrowband Lamb wave detection signals, and sensitivity analysis of the proposed time-frequency energy density precipitation method is performed in terms of propagation distance, dispersion characteristics, center frequency, and plate thickness. For comparison, the widely used Hilbert-Huang transform method is also implemented for time-of-flight extraction. The results show that the time-frequency energy density precipitation method can accurately extract the time-of-flight with relative error of <1% and thus can act as a universal time-of-flight extraction method for narrowband Lamb wave detection signals.

  11. Upgrade of the ALICE inner tracking system

    NASA Astrophysics Data System (ADS)

    Rossegger, Stefan

    2013-12-01

    The Inner Tracking System (ITS) is the key ALICE detector for the study of heavy flavor production at LHC. Heavy flavor can be studied via the identification of short-lived hadrons containing heavy quarks which have a mean proper decay length in the order of 100-300 μm. To accomplish this task, the ITS is composed of six cylindrical layers of silicon detectors (two pixel, two drift and two strip) with a radial coverage from 3.9 to 43 cm and an average material budget of 1.1% X0 per layer. In order to enhance the ALICE physics capabilities, and, in particular, the tracking performance for heavy-flavor detection, the possibility of an ITS upgrade has been studied in great detail. It will make use of the spectacular progress made in the field of imaging sensors over the last 10 years as well as the possibility to install a smaller radius beampipe. The upgraded detector will have greatly improved features in terms of the impact parameter resolution, standalone tracking efficiency at low pt, momentum resolution and readout capabilities. The usage of the most recent monolithic and/or hybrid pixel detector technologies allows the improvement of the detector material budget and the intrinsic spatial resolution both by a factor of three with respect to the present ITS. The installation of a smaller beam-pipe reduces the distance between the first detector layer and the interaction vertex. Under these assumptions, simulations show that an overall improvement of the impact parameter resolution by a factor of three is possible. The Conceptual Design Report for the Upgrade of the ALICE ITS, which covers the design and performance requirements, the upgrade options, as well as the necessary R&D efforts, was made public in September 2012. An intensive R&D program has been launched to review the different technological options under consideration. The new detector should be ready to be installed during the long LHC shutdown period scheduled in 2017-2018.

  12. Methodology for the neutron time of flight measurement of 120-GeV proton-induced reactions on a thick copper target

    DOE PAGES

    Sanami, T.; Iwamoto, Y.; Kajimoto, T.; ...

    2011-12-06

    Our methodology for the time-of-flight measurement of the neutron energy spectrum for a high-energy proton-beam-induced reaction was established at the Fermilab Test Beam Facility of the Fermi National Accelerator Laboratory. The 120-GeV proton beam with 3 × 105 protons/spill was prepared for event-by-event counting of incident protons and emitted neutrons for time-of-flight energy determination. An NE213 organic liquid scintillator (12.7 cm in diameter by 12.7 cm in length) was employed with a veto plastic scintillator and a pulse-shape discrimination technique to identify neutrons. Raw waveforms of NE213, veto and beam detectors were recorded to discriminate the effects of multi-proton beammore » events by considering different time windows. The neutron energy spectrum ranging from 10 to 800 MeV was obtained for a 60-cm-long copper target at 90° with respect to the beam axis. Finally our obtained spectrum was consistent with that deduced employing the conventional unfolding technique as well as that obtained in a 40-GeV/c thin-target experiment.« less

  13. Light output function and assembly of the time-of-flight enhanced diagnostics neutron spectrometer plastic scintillators for background reduction by double kinematic selection at EAST

    SciTech Connect

    Peng, X. Y.; Chen, Z. J.; Zhang, X.; Hu, Z. M.; Du, T. F.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Yuan, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.; Gorini, G.; Nocente, M.; Tardocchi, M.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.

    2014-11-15

    The 2.5 MeV neutron spectrometer TOFED (Time-Of-Flight Enhanced Diagnostics) has been constructed to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas on EAST. The instrument has a double-ring structure which, in combination with pulse shape digitization, allows for a dual kinematic selection in the time-of-flight/recoil proton energy (tof/E{sub p}) space, thus improving the spectrometer capability to resolve fast ion signatures in the neutron spectrum, in principle up to a factor ≈100. The identification and separation of features from the energetic ions in the neutron spectrum depends on the detailed knowledge of the instrument response function, both in terms of the light output function of the scintillators and the effect of undesired multiple neutron scatterings in the instrument. This work presents the determination of the light output function of the TOFED plastic scintillator detectors and their geometrical assembly. Results from dedicated experiments with γ-ray sources and quasi-monoenergetic neutron beams are presented. Implications on the instrument capability to perform background suppression based on double kinematic selection are discussed.

  14. Methodology for the neutron time of flight measurement of 120-GeV proton-induced reactions on a thick copper target

    SciTech Connect

    Sanami, T.; Iwamoto, Y.; Kajimoto, T.; Shigyo, N.; Hagiwara, M.; Lee, H. S.; Ramberg, E.; Coleman, R.; Soha, A.; Jensen, D.; Leveling, A.; Mokhov, N. V.; Boehnlein, D.; Vaziri, K.; Ishibashi, K.; Sakamoto, Y.; Nakashima, H.

    2011-12-06

    Our methodology for the time-of-flight measurement of the neutron energy spectrum for a high-energy proton-beam-induced reaction was established at the Fermilab Test Beam Facility of the Fermi National Accelerator Laboratory. The 120-GeV proton beam with 3 × 105 protons/spill was prepared for event-by-event counting of incident protons and emitted neutrons for time-of-flight energy determination. An NE213 organic liquid scintillator (12.7 cm in diameter by 12.7 cm in length) was employed with a veto plastic scintillator and a pulse-shape discrimination technique to identify neutrons. Raw waveforms of NE213, veto and beam detectors were recorded to discriminate the effects of multi-proton beam events by considering different time windows. The neutron energy spectrum ranging from 10 to 800 MeV was obtained for a 60-cm-long copper target at 90° with respect to the beam axis. Finally our obtained spectrum was consistent with that deduced employing the conventional unfolding technique as well as that obtained in a 40-GeV/c thin-target experiment.

  15. Light output function and assembly of the time-of-flight enhanced diagnostics neutron spectrometer plastic scintillators for background reduction by double kinematic selection at EAST

    NASA Astrophysics Data System (ADS)

    Peng, X. Y.; Chen, Z. J.; Zhang, X.; Hu, Z. M.; Du, T. F.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Yuan, X.; Gorini, G.; Nocente, M.; Tardocchi, M.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.

    2014-11-01

    The 2.5 MeV neutron spectrometer TOFED (Time-Of-Flight Enhanced Diagnostics) has been constructed to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas on EAST. The instrument has a double-ring structure which, in combination with pulse shape digitization, allows for a dual kinematic selection in the time-of-flight/recoil proton energy (tof/Ep) space, thus improving the spectrometer capability to resolve fast ion signatures in the neutron spectrum, in principle up to a factor ≈100. The identification and separation of features from the energetic ions in the neutron spectrum depends on the detailed knowledge of the instrument response function, both in terms of the light output function of the scintillators and the effect of undesired multiple neutron scatterings in the instrument. This work presents the determination of the light output function of the TOFED plastic scintillator detectors and their geometrical assembly. Results from dedicated experiments with γ-ray sources and quasi-monoenergetic neutron beams are presented. Implications on the instrument capability to perform background suppression based on double kinematic selection are discussed.

  16. NOTE: LaBr3:Ce and SiPMs for time-of-flight PET: achieving 100 ps coincidence resolving time

    NASA Astrophysics Data System (ADS)

    Schaart, Dennis R.; Seifert, Stefan; Vinke, Ruud; van Dam, Herman T.; Dendooven, Peter; Löhner, Herbert; Beekman, Freek J.

    2010-04-01

    The use of time-of-flight (TOF) information in positron emission tomography (PET) enables significant improvement in image noise properties and, therefore, lesion detection. Silicon photomultipliers (SiPMs) are solid-state photosensors that have several advantages over photomultiplier tubes (PMTs). SiPMs are small, essentially transparent to 511 keV gamma rays and insensitive to magnetic fields. This enables novel detector designs aimed at e.g. compactness, high resolution, depth-of-interaction (DOI) correction and MRI compatibility. The goal of the present work is to study the timing performance of SiPMs in combination with LaBr3:Ce(5%), a relatively new scintillator with promising characteristics for TOF-PET. Measurements were performed with two, bare, 3 mm × 3 mm × 5 mm LaBr3:Ce(5%) crystals, each coupled to a 3 mm × 3 mm SiPM. Using a 22Na point source placed at various positions in between the two detectors, a coincidence resolving time (CRT) of ~100 ps FWHM for 511 keV annihilation photon pairs was achieved, corresponding to a TOF positioning resolution of ~15 mm FWHM. At the same time, pulse height spectra with well-resolved full-energy peaks were obtained. To our knowledge this is the best CRT reported for SiPM-based scintillation detectors to date. It is concluded that SiPM-based scintillation detectors can provide timing resolutions at least as good as detectors based on PMTs.

  17. Toward Respiratory Assessment Using Depth Measurements from a Time-of-Flight Sensor

    PubMed Central

    Sharp, Charles; Soleimani, Vahid; Hannuna, Sion; Camplani, Massimo; Damen, Dima; Viner, Jason; Mirmehdi, Majid; Dodd, James W.

    2017-01-01

    Introduction: There is increasing interest in technologies that may enable remote monitoring of respiratory disease. Traditional methods for assessing respiratory function such as spirometry can be expensive and require specialist training to perform and interpret. Remote, non-contact tracking of chest wall movement has been explored in the past using structured light, accelerometers and impedance pneumography, but these have often been costly and clinical utility remains to be defined. We present data from a 3-Dimensional time-of-flight camera (found in gaming consoles) used to estimate chest volume during routine spirometry maneuvres. Methods: Patients were recruited from a general respiratory physiology laboratory. Spirometry was performed according to international standards using an unmodified spirometer. A Microsoft Kinect V2 time-of-flight depth sensor was used to reconstruct 3-dimensional models of the subject's thorax to estimate volume-time and flow-time curves following the introduction of a scaling factor to transform measurements to volume estimates. The Bland-Altman method was used to assess agreement of model estimation with simultaneous recordings from the spirometer. Patient characteristics were used to assess predictors of error using regression analysis and to further explore the scaling factors. Results: The chest volume change estimated by the Kinect camera during spirometry tracked respiratory rate accurately and estimated forced vital capacity (FVC) and vital capacity to within ± <1%. Forced expiratory volume estimation did not demonstrate acceptable limits of agreement, with 61.9% of readings showing >150 ml difference. Linear regression including age, gender, height, weight, and pack years of smoking explained 37.0% of the variance in the scaling factor for volume estimation. This technique had a positive predictive value of 0.833 to detect obstructive spirometry. Conclusion: These data illustrate the potential of 3D time-of-flight cameras

  18. Toward Respiratory Assessment Using Depth Measurements from a Time-of-Flight Sensor.

    PubMed

    Sharp, Charles; Soleimani, Vahid; Hannuna, Sion; Camplani, Massimo; Damen, Dima; Viner, Jason; Mirmehdi, Majid; Dodd, James W

    2017-01-01

    Introduction: There is increasing interest in technologies that may enable remote monitoring of respiratory disease. Traditional methods for assessing respiratory function such as spirometry can be expensive and require specialist training to perform and interpret. Remote, non-contact tracking of chest wall movement has been explored in the past using structured light, accelerometers and impedance pneumography, but these have often been costly and clinical utility remains to be defined. We present data from a 3-Dimensional time-of-flight camera (found in gaming consoles) used to estimate chest volume during routine spirometry maneuvres. Methods: Patients were recruited from a general respiratory physiology laboratory. Spirometry was performed according to international standards using an unmodified spirometer. A Microsoft Kinect V2 time-of-flight depth sensor was used to reconstruct 3-dimensional models of the subject's thorax to estimate volume-time and flow-time curves following the introduction of a scaling factor to transform measurements to volume estimates. The Bland-Altman method was used to assess agreement of model estimation with simultaneous recordings from the spirometer. Patient characteristics were used to assess predictors of error using regression analysis and to further explore the scaling factors. Results: The chest volume change estimated by the Kinect camera during spirometry tracked respiratory rate accurately and estimated forced vital capacity (FVC) and vital capacity to within ± <1%. Forced expiratory volume estimation did not demonstrate acceptable limits of agreement, with 61.9% of readings showing >150 ml difference. Linear regression including age, gender, height, weight, and pack years of smoking explained 37.0% of the variance in the scaling factor for volume estimation. This technique had a positive predictive value of 0.833 to detect obstructive spirometry. Conclusion: These data illustrate the potential of 3D time-of-flight cameras

  19. Neutral meson production measurements with the ALICE at the LHC

    NASA Astrophysics Data System (ADS)

    Ganoti, Paraskevi

    2017-03-01

    Identified hadron spectra are considered to be sensitive to the transport properties of strongly interacting matter produced in high-energy nucleus-nucleus collisions. π0 and η mesons in ALICE are identified via their two-photon decays by using calorimeters and the central tracking system. In the latter, photons are measured via their conversion to electron-positron pairs in the material of the inner ALICE barrel tracking detectors. The measured production spectra in pp, p-Pb and Pb-Pb collisions at mid-rapidity and over a wide pT range will be presented in the available Large Hadron Collider (LHC) energies of Run I. The resulting nuclear modification factor RAA at different centrality classes shows a clear pattern of strong suppression in the hot QCD medium with respect to pp collisions. Comparison of the ALICE results on neutral mesons with lower-energy experiments is also discussed.

  20. The Impact II, a Very High-Resolution Quadrupole Time-of-Flight Instrument (QTOF) for Deep Shotgun Proteomics.

    PubMed

    Beck, Scarlet; Michalski, Annette; Raether, Oliver; Lubeck, Markus; Kaspar, Stephanie; Goedecke, Niels; Baessmann, Carsten; Hornburg, Daniel; Meier, Florian; Paron, Igor; Kulak, Nils A; Cox, Juergen; Mann, Matthias

    2015-07-01

    Hybrid quadrupole time-of-flight (QTOF) mass spectrometry is one of the two major principles used in proteomics. Although based on simple fundamentals, it has over the last decades greatly evolved in terms of achievable resolution, mass accuracy, and dynamic range. The Bruker impact platform of QTOF instruments takes advantage of these developments and here we develop and evaluate the impact II for shotgun proteomics applications. Adaption of our heated liquid chromatography system achieved very narrow peptide elution peaks. The impact II is equipped with a new collision cell with both axial and radial ion ejection, more than doubling ion extraction at high tandem MS frequencies. The new reflectron and detector improve resolving power compared with the previous model up to 80%, i.e. to 40,000 at m/z 1222. We analyzed the ion current from the inlet capillary and found very high transmission (>80%) up to the collision cell. Simulation and measurement indicated 60% transfer into the flight tube. We adapted MaxQuant for QTOF data, improving absolute average mass deviations to better than 1.45 ppm. More than 4800 proteins can be identified in a single run of HeLa digest in a 90 min gradient. The workflow achieved high technical reproducibility (R2 > 0.99) and accurate fold change determination in spike-in experiments in complex mixtures. Using label-free quantification we rapidly quantified haploid against diploid yeast and characterized overall proteome differences in mouse cell lines originating from different tissues. Finally, after high pH reversed-phase fractionation we identified 9515 proteins in a triplicate measurement of HeLa peptide mixture and 11,257 proteins in single measurements of cerebellum-the highest proteome coverage reported with a QTOF instrument so far.

  1. The Impact II, a Very High-Resolution Quadrupole Time-of-Flight Instrument (QTOF) for Deep Shotgun Proteomics*

    PubMed Central

    Beck, Scarlet; Michalski, Annette; Raether, Oliver; Lubeck, Markus; Kaspar, Stephanie; Goedecke, Niels; Baessmann, Carsten; Hornburg, Daniel; Meier, Florian; Paron, Igor; Kulak, Nils A.; Cox, Juergen; Mann, Matthias

    2015-01-01

    Hybrid quadrupole time-of-flight (QTOF) mass spectrometry is one of the two major principles used in proteomics. Although based on simple fundamentals, it has over the last decades greatly evolved in terms of achievable resolution, mass accuracy, and dynamic range. The Bruker impact platform of QTOF instruments takes advantage of these developments and here we develop and evaluate the impact II for shotgun proteomics applications. Adaption of our heated liquid chromatography system achieved very narrow peptide elution peaks. The impact II is equipped with a new collision cell with both axial and radial ion ejection, more than doubling ion extraction at high tandem MS frequencies. The new reflectron and detector improve resolving power compared with the previous model up to 80%, i.e. to 40,000 at m/z 1222. We analyzed the ion current from the inlet capillary and found very high transmission (>80%) up to the collision cell. Simulation and measurement indicated 60% transfer into the flight tube. We adapted MaxQuant for QTOF data, improving absolute average mass deviations to better than 1.45 ppm. More than 4800 proteins can be identified in a single run of HeLa digest in a 90 min gradient. The workflow achieved high technical reproducibility (R2 > 0.99) and accurate fold change determination in spike-in experiments in complex mixtures. Using label-free quantification we rapidly quantified haploid against diploid yeast and characterized overall proteome differences in mouse cell lines originating from different tissues. Finally, after high pH reversed-phase fractionation we identified 9515 proteins in a triplicate measurement of HeLa peptide mixture and 11,257 proteins in single measurements of cerebellum—the highest proteome coverage reported with a QTOF instrument so far. PMID:25991688

  2. Time-of-flight mobility and trapping results for ZnSe.

    NASA Technical Reports Server (NTRS)

    Heaton, J. L., III; Hammond, G. H.; Goldner, R. B.

    1972-01-01

    Results of measurements of time-of-flight mobility and trapping for zinc selenide. The data were obtained at room temperature for electric fields in the range from 30,000 to 800,000 V/cm. A relatively constant hole mobility (about 50 sq cm/V sec) was found for the entire range of investigated fields. The electron mobility was approximately constant (about 400 sq cm/V sec) up to approximately equal to 300,000 V/cm, above which the drift velocity remained constant. No obvious negative differential mobility was observed, even though the Gunn effect has been reported for the field range investigated. Trapping and detrapping times in the vicinity of 1 nsec are reported for both holes and electrons. The field dependence of the electron-trapping times is unusual and remains unexplained.

  3. Campaign 1.7 Pu Aging. Development of Time of Flight Secondary Ion Mass Spectroscopy

    SciTech Connect

    Venhaus, Thomas J.

    2015-09-09

    The first application of Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) to an aged plutonium surface has resulted in a rich set of surface chemistry data, as well as some unexpected results. FY15 was highlighted by not only the first mapping of hydrogen-containing features within the metal, but also a prove-in series of experiments using the system’s Sieverts Reaction Cell. These experiments involved successfully heating the sample to ~450 oC for nearly 24 hours while the sample was dosed several times with hydrogen, followed by an in situ ToF-SIMS analysis. During this year, the data allowed for better and more consistent identification of the myriad peaks that result from the SIMS sputter process. In collaboration with the AWE (U.K), the system was also fully aligned for sputter depth profiling for future experiments.

  4. Analyzing neutron time-of-flight spectra from the National Ignition Facility using moments

    NASA Astrophysics Data System (ADS)

    Hatarik, R.; Field, J.; Eckart, M.; Grim, G.; Hartouni, E. P.; Moore, A.; Munro, D.; Sayre, D.

    2016-10-01

    The neutron spectrum produced by an indirectly driven implosion at the National Ignition Facility (NIF) provides valuable insight into the performance of the capsule. There are four neutron time-of-flight (nTOF) spectrometers being used at the NIF which can simultaneously measure DD and DT fusion neutrons on NIF shots. The width of theses peaks have been traditionally associated with the temperature of the plasma, recent work shows that it has to be considered a combination of flow and temperature distributions. This leads to a deviation from a pure gaussian shape of a single temperature static plasma and the presence of higher order moments in the neutron spectrum. The current status of the analysis of neutron spectra from the nTOF diagnostics at the NIF will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  5. High precision electric gate for time-of-flight ion mass spectrometers

    NASA Technical Reports Server (NTRS)

    Sittler, Edward C. (Inventor)

    2011-01-01

    A time-of-flight mass spectrometer having a chamber with electrodes to generate an electric field in the chamber and electric gating for allowing ions with a predetermined mass and velocity into the electric field. The design uses a row of very thin parallel aligned wires that are pulsed in sequence so the ion can pass through the gap of two parallel plates, which are biased to prevent passage of the ion. This design by itself can provide a high mass resolution capability and a very precise start pulse for an ion mass spectrometer. Furthermore, the ion will only pass through the chamber if it is within a wire diameter of the first wire when it is pulsed and has the right speed so it is near all other wires when they are pulsed.

  6. Denoising and Multivariate Analysis of Time-Of-Flight SIMS Images

    SciTech Connect

    Wickes, Bronwyn; Kim, Y.; Castner, David G.

    2003-08-30

    Time-of-flight SIMS (ToF-SIMS) imaging offers a modality for simultaneously visualizing the spatial distribution of different surface species. However, the utility of ToF-SIMS datasets may be limited by their large size, degraded mass resolution and low ion counts per pixel. Through denoising and multivariate image analysis, regions of similar chemistries may be differentiated more readily in ToF-SIMS image data. Three established denoising algorithms down-binning, boxcar and wavelet filtering were applied to ToF-SIMS images of different surface geometries and chemistries. The effect of these filters on the performance of principal component analysis (PCA) was evaluated in terms of the capture of important chemical image features in the principal component score images, the quality of the principal component

  7. Time of flight spectrometer for background-free positron annihilation induced Auger electron spectroscopy.

    PubMed

    Mukherjee, S; Shastry, K; Anto, C V; Joglekar, P V; Nadesalingam, M P; Xie, S; Jiang, N; Weiss, A H

    2016-03-01

    We describe a novel spectrometer designed for positron annihilation induced Auger electron spectroscopy employing a time-of-flight spectrometer. The spectrometer's new configuration enables us to implant monoenergetic positrons with kinetic energies as low as 1.5 eV on the sample while simultaneously allowing for the detection of electrons emitted from the sample surface at kinetic energies ranging from ∼500 eV to 0 eV. The spectrometer's unique characteristics made it possible to perform (a) first experiments demonstrating the direct transition of a positron from an unbound scattering state to a bound surface state and (b) the first experiments demonstrating that Auger electron spectra can be obtained down to 0 eV without the beam induced secondary electron background obscuring the low energy part of the spectra. Data are presented which show alternative means of estimating positron surface state binding energy and background-free Auger spectra.

  8. Invited article: polarization "down under": the polarized time-of-flight neutron reflectometer PLATYPUS.

    PubMed

    Saerbeck, T; Klose, F; Le Brun, A P; Füzi, J; Brule, A; Nelson, A; Holt, S A; James, M

    2012-08-01

    This review presents the implementation and full characterization of the polarization equipment of the time-of-flight neutron reflectometer PLATYPUS at the Australian Nuclear Science and Technology Organisation (ANSTO). The functionality and efficiency of individual components are evaluated and found to maintain a high neutron beam polarization with a maximum of 99.3% through polarizing Fe/Si supermirrors. Neutron spin-flippers with efficiencies of 99.7% give full control over the incident and scattered neutron spin direction over the whole wavelength spectrum available in the instrument. The first scientific experiments illustrate data correction mechanisms for finite polarizations and reveal an extraordinarily high reproducibility for measuring magnetic thin film samples. The setup is now fully commissioned and available for users through the neutron beam proposal system of the Bragg Institute at ANSTO.

  9. Porosity detection in ceramic armor tiles via ultrasonic time-of-flight

    SciTech Connect

    Margetan, Frank J.; Richter, Nathaniel; Jensen, Terrence

    2011-06-23

    Some multilayer armor panels contain ceramic tiles as one constituent, and porosity in the tiles can affect armor performance. It is well known that porosity in ceramic materials leads to a decrease in ultrasonic velocity. We report on a feasibility study exploring the use of ultrasonic time-of-flight (TOF) to locate and characterize porous regions in armor tiles. The tiles in question typically have well-controlled thickness, thus simplifying the translation of TOF data into velocity data. By combining UT velocity measurements and X-ray absorption measurements on selected specimens, one can construct a calibration curve relating velocity to porosity. That relationship can then be used to translate typical ultrasonic C-scans of TOF-versus-position into C-scans of porosity-versus-position. This procedure is demonstrated for pulse/echo, focused-transducer inspections of silicon carbide (SiC) ceramic tiles.

  10. Detection of chlorobenzene derivatives using vacuum ultraviolet ionization time-of-flight mass spectrometry.

    PubMed

    Tonokura, Kenichi; Nakamura, Tomohisa; Koshi, Mitsuo

    2003-08-01

    Vacuum ultraviolet single-photon ionization time-of-flight mass spectrometry (VUV-SPI-TOFMS) has been applied for the detection of chlorobenzene, o-dichlorobenzene, and o-chlorophenol as surrogates for polychlorinated dibenzo-p-dioxine/furans (PCDD/F). The photoionization mass spectra of these compounds appear to be fragmentation free in the ionization processes by the VUV-SPI at 10.2 eV (121.6 nm). Quantum chemical calculations support no fragmentation in the photoionization of chlorobenzene derivatives at around 10 eV. The absolute photoionization cross-sections of chlorobenzene, o-dichlorobenzene, and o-chlorophenol were estimated at 10.2 eV. The photoionization cross-section is an important parameter in the detection of chlorobenzene derivatives by the single-photon ionization technique. The detection limit for chlorobenzene is on the order of tenth parts-per-billion volume (ppbv) in the present experimental setup.

  11. Laser time-of-flight measurement based on time-delay estimation and fitting correction

    NASA Astrophysics Data System (ADS)

    Li, Chao; Chen, Qian; Gu, Guohua; Qian, Weixian

    2013-07-01

    We describe a method based on multichannel time-delay estimation with linear fitting correction for laser time-of-flight (TOF) measurement. The laser TOF measurement system is constructed with a laser source, a stop receiver channel, a reference receiver multichannel, an analog to digital converter (ADC) sampling unit, and a digital signal processing unit. Limited by the sampling rate, the precision of laser TOF measurement is restricted no more than the ADC sampling period in conventional methods. As this problem is considered, multichannel correlation time-delay estimation with linear fitting correction is devised. It is shown that the measuring precision is better than 2 ns with multichannel time-delay estimation and not influenced by signal-to-noise ratio. The experimental results demonstrate that the proposed method is effective and stable.

  12. Laser time-of-flight measurement based on multi-channel time delay estimation

    NASA Astrophysics Data System (ADS)

    Li, Chao; Chen, Qian; Gu, Guohua; Man, Tian

    2013-03-01

    In this paper, a novel method based on multichannel time delay estimation with linear fitting correction for laser time-of-flight (TOF) measurement is described. The laser TOF measurement system is constructed with a laser source, a stop receiver channel, a reference receiver multichannel, an ADC sampling unit and a digital signal processing unit. Limited by the sampling rate, the precision of laser TOF measurement is restricted no more than the ADC sampling period in conventional methods. As this problem is considered, multi-channel correlation time delay estimation with linear fitting correction is devised. It is shown that the measuring precision is better than 2ns with multi-channel time delay estimation and not influenced by SNR. The experimental results demonstrate that the proposed method is effective and stable.

  13. Asymmetric band flipping for time-of-flight neutron diffraction data

    SciTech Connect

    Whitfield, Pamela S.; Coelho, Alan A.

    2016-08-24

    Charge flipping with powder diffraction data is known to produce a result more reliably with high-resolution data,i.e.visible reflections at smalldspacings. This data are readily accessible with the neutron time-of-flight technique but the assumption that negative scattering density is nonphysical is no longer valid where elements with negative scattering lengths are present. The concept of band flipping was introduced in the literature, where a negative threshold is used in addition to a positive threshold during the flipping. But, it was not tested with experimental data at the time. Finallly, band flipping has been implemented inTOPAStogether with the band modification of low-density elimination and tested with experimental powder and Laue single-crystal neutron data.

  14. Stopping power measurements with the Time-of-Flight (ToF) technique

    SciTech Connect

    Fontana, Cristiano L.; Chen, Chien-Hung; Crespillo, Miguel L.; Graham, Joseph T.; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-11-10

    In our review of measurements of the stopping power of ions in matter is presented along with new measurements of the stopping powers of O, Si, Ti, and Au ions in self-supporting thin foils of SiO2, Nb2O5, and Ta2O5. Moreover, a Time-of-Flight system at the Ion Beam Materials Laboratory at the University of Tennessee, Knoxville, was used in transmission geometry in order to reduce experimental uncertainties. Finally, the resulting stopping powers show good precision and accuracy and corroborate previously quoted values in the literature. New stopping data are determined.

  15. A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source

    SciTech Connect

    Stone, M. B.; Abernathy, D. L.; Ehlers, G.; Garlea, O.; Podlesnyak, A.; Winn, B.; Niedziela, J. L.; DeBeer-Schmitt, L.; Graves-Brook, M.; Granroth, G. E.; Kolesnikov, A. I.

    2014-04-15

    The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave-vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments are not exclusive and overlap significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

  16. Asymmetric band flipping for time-of-flight neutron diffraction data

    DOE PAGES

    Whitfield, Pamela S.; Coelho, Alan A.

    2016-08-24

    Charge flipping with powder diffraction data is known to produce a result more reliably with high-resolution data,i.e.visible reflections at smalldspacings. This data are readily accessible with the neutron time-of-flight technique but the assumption that negative scattering density is nonphysical is no longer valid where elements with negative scattering lengths are present. The concept of band flipping was introduced in the literature, where a negative threshold is used in addition to a positive threshold during the flipping. But, it was not tested with experimental data at the time. Finallly, band flipping has been implemented inTOPAStogether with the band modification of low-densitymore » elimination and tested with experimental powder and Laue single-crystal neutron data.« less

  17. Delayed bunching for multi-reflection time-of-flight mass separation

    SciTech Connect

    Rosenbusch, M.; Marx, G.; Schweikhard, L.; Wienholtz, F.; Chauveau, P.; Delahaye, P.

    2015-06-29

    Many experiments are handicapped when the ion sources do not only deliver the ions of interest but also contaminations, i.e., unwanted ions of similar mass. In the recent years, multi-reflection time-of-flight mass separation has become a promising method to isolate the ions of interest from the contaminants, in particular for measurements with low-energy short-lived nuclides. To further improve the performance of multi-reflection mass separators with respect to the limitations by space-charge effects, the simultaneously trapped ions are spatially widely distributed in the apparatus. Thus, the ions can propagate with reduced Coulomb interactions until, finally, they are bunched by a change in the trapping conditions for high-resolution mass separation. Proof-of-principle measurements are presented.

  18. Invited Article: Polarization ``Down Under'': The polarized time-of-flight neutron reflectometer PLATYPUS

    NASA Astrophysics Data System (ADS)

    Saerbeck, T.; Klose, F.; Le Brun, A. P.; Füzi, J.; Brule, A.; Nelson, A.; Holt, S. A.; James, M.

    2012-08-01

    This review presents the implementation and full characterization of the polarization equipment of the time-of-flight neutron reflectometer PLATYPUS at the Australian Nuclear Science and Technology Organisation (ANSTO). The functionality and efficiency of individual components are evaluated and found to maintain a high neutron beam polarization with a maximum of 99.3% through polarizing Fe/Si supermirrors. Neutron spin-flippers with efficiencies of 99.7% give full control over the incident and scattered neutron spin direction over the whole wavelength spectrum available in the instrument. The first scientific experiments illustrate data correction mechanisms for finite polarizations and reveal an extraordinarily high reproducibility for measuring magnetic thin film samples. The setup is now fully commissioned and available for users through the neutron beam proposal system of the Bragg Institute at ANSTO.

  19. Data acquisition system with pulse height capability for the TOFED time-of-flight neutron spectrometer

    SciTech Connect

    Chen, Z. J.; Peng, X. Y.; Zhang, X.; Du, T. F.; Hu, Z. M.; Cui, Z. Q.; Ge, L. J.; Xie, X. F.; Yuan, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.; Gorini, G.; Nocente, M.; Tardocchi, M.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.

    2014-11-15

    A new time-of-flight neutron spectrometer TOFED has been constructed for installation at Experimental Advanced Superconducting Tokamak. A data acquisition system combining measurements of flight time and energy from the interaction of neutrons with the TOFED scintillators has been developed. The data acquisition system can provide a digitizing resolution better than 1.5% (to be compared with the >10% resolution of the recoil particle energy in the plastic scintillators) and a time resolution <1 ns. At the same time, it is compatible with high count rate event recording, which is an essential feature to investigate phenomena occurring on time scales faster than the slowing down time (≈100 ms) of the beam ions in the plasma. Implications of these results on the TOFED capability to resolve fast ion signatures in the neutron spectrum from EAST plasmas are discussed.

  20. Data acquisition system with pulse height capability for the TOFED time-of-flight neutron spectrometer.

    PubMed

    Chen, Z J; Peng, X Y; Zhang, X; Du, T F; Hu, Z M; Cui, Z Q; Ge, L J; Xie, X F; Yuan, X; Gorini, G; Nocente, M; Tardocchi, M; Hu, L Q; Zhong, G Q; Lin, S Y; Wan, B N; Li, X Q; Zhang, G H; Chen, J X; Fan, T S

    2014-11-01

    A new time-of-flight neutron spectrometer TOFED has been constructed for installation at Experimental Advanced Superconducting Tokamak. A data acquisition system combining measurements of flight time and energy from the interaction of neutrons with the TOFED scintillators has been developed. The data acquisition system can provide a digitizing resolution better than 1.5% (to be compared with the >10% resolution of the recoil particle energy in the plastic scintillators) and a time resolution <1 ns. At the same time, it is compatible with high count rate event recording, which is an essential feature to investigate phenomena occurring on time scales faster than the slowing down time (≈100 ms) of the beam ions in the plasma. Implications of these results on the TOFED capability to resolve fast ion signatures in the neutron spectrum from EAST plasmas are discussed.

  1. Integrated multi-channel receiver for a pulsed time-of-flight laser radar

    NASA Astrophysics Data System (ADS)

    Jiang, Yan; Liu, Ruqing; Zhu, Jingguo

    2015-04-01

    An integrated multi-channel receiver for a pulsed time-of-flight (TOF) laser rangefinder has been designed in this paper. The receiver chip as an important component of the laser radar device has been implemented in a 0.18um CMOS process. It consists of sixteen channels and every channel includes preamplifier, amplifier stages, high-pass filter and a timing discriminator which contains a timing comparator and a noise comparator. Each signal paths is independent of other channels. Based on the simulations, the bandwidth and transimpedance of the amplifier channel are 652MHz, 99dBΩ. Under the simulation condition of TT corner and 27°C, the propagation delay of the discriminator is 2.15ns and the propagation delay dispersion is 223ps. The power consumption during continuous measurement is 810mW, and the operating temperature range of the device is -10~60°C.

  2. Quantum fluctuations and condensate fraction during time-of-flight expansion

    SciTech Connect

    Fang Shiang; Lee, Ray-Kuang; Wang, Daw-Wei

    2010-09-15

    The quantum fluctuation effects in the time-of-flight (TOF) experiment for a condensate released from an optical-lattice potential is studied within the truncated Wigner approximation. By investigating both the spatial and momentum density distributions, we find that the condensate fraction decreases monotonically in time and hence cannot be measured in the standard TOF image. We then propose a semiquantitative analysis for such dynamical quantum-depletion process. Our study shows a universal algebraic decay of the true condensate fraction, and has a very good agreement with numerical results. We also discuss possible methods to determine the condensate fraction inside the optical lattice, and its implication to the TOF experiments in higher dimensional systems.

  3. Objective Error Criterion for Evaluation of Mapping Accuracy Based on Sensor Time-of-Flight Measurements.

    PubMed

    Barshan, Billur

    2008-12-15

    An objective error criterion is proposed for evaluating the accuracy of maps of unknown environments acquired by making range measurements with different sensing modalities and processing them with different techniques. The criterion can also be used for the assessment of goodness of fit of curves or shapes fitted to map points. A demonstrative example from ultrasonic mapping is given based on experimentally acquired time-of-flight measurements and compared with a very accurate laser map, considered as absolute reference. The results of the proposed criterion are compared with the Hausdorff metric and the median error criterion results. The error criterion is sufficiently general and flexible that it can be applied to discrete point maps acquired with other mapping techniques and sensing modalities as well.

  4. Development of a correction method for the time-of-flight prompt gamma-ray analysis

    NASA Astrophysics Data System (ADS)

    Huang, M.; Toh, Y.; Ebihara, M.; Kimura, A.; Nakamura, S.

    2017-03-01

    A new analytical technique, time-of-flight prompt gamma-ray analysis, has been developed at the Japan Proton Accelerator Research Complex. In order to apply it to accurate elemental analysis, a set of Fe and Au reference samples were measured to examine the several factors which affect the number of detected events. It was found that major contributing factors included attenuations of neutrons and gamma rays in the sample, live-time fraction and signal pile-up correction. A simulation model was built for the estimation of neutron and gamma-ray attenuations. A simple empirical formula was proposed to calculate the signal pile-up correction factor. The whole correction method has proven to be accurate and reliable.

  5. Atom-atom correlations in time-of-flight imaging of ultracold bosons in optical lattices

    SciTech Connect

    Zaleski, T. A.; Kopec, T. K.

    2011-11-15

    We study the spatial correlations of strongly interacting bosons in a ground state, confined in a two-dimensional square and a three-dimensional cubic lattice. Using the combined Bogoliubov method and the quantum rotor approach, we map the Hamiltonian of strongly interacting bosons onto U(1) phase action in order to calculate the atom-atom correlations' decay along the principal axis and a diagonal of the lattice-plane direction as a function of distance. Lower tunneling rates lead to quicker decays of the correlations, whose character becomes exponential. Finally, correlation functions allow us to calculate quantities that are directly bound to experimental outcomes, namely time-of-flight absorption images and resulting visibility. Our results contain all the characteristic features present in experimental data (transition from Mott insulating blob to superfluid peaks, etc.), emphasizing the usability of the proposed approach.

  6. Studies of polyisobutylene using time-of-flight secondary ion mass spectrometry (TOF-SIMS)

    NASA Astrophysics Data System (ADS)

    Xu, Keyang; Proctor, Andrew; Hercules, David M.

    1995-05-01

    A series of polyisobutylenes (PIBs) with average molecular weights from 800 to 4 × 105 were analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The PIB spectra consist of a sequence of repeating patterns. Four clusters are observed within each pattern. Each cluster corresponds to several species, which are neutral fragments generated from polymer chain scission, cationized by a silver ion. The species formed have various numbers of double bonds and/or rings, and are separated by two mass units. The data indicate that the average molecular weight of PIB affects the ion formation. It changes the relative cluster intensities in a pattern, and also varies the cluster structures. More fragment-ion species can be detected from a high molecular weight polymer, and the unsaturated fragments are predominant. In addition to the large fragments, small fragment ions also provide information about some structurally important features.

  7. New high-resolution electrostatic ion mass analyzer using time of flight

    NASA Technical Reports Server (NTRS)

    Hamilton, D. C.; Gloeckler, G.; Ipavich, F. M.; Lundgren, R. A.; Sheldon, R. B.

    1990-01-01

    The design of a high-resolution ion-mass analyzer is described, which is based on an accurate measurement of the time of flight (TOF) of ions within a region configured to produce a harmonic potential. In this device, the TOF, which is independent of ion energy, is determined from a start pulse from secondary electrons produced when the ion passes through a thin carbon foil at the entrance of the TOF region and at a stop pulse from the ion striking a microchannel plate upon exciting the region. A laboratory prototype instrument called 'VMASS' was built and was tested at the Goddard Space Flight Center electrostatic accelerator, showing a good mass resolution of the instrument. Sensors of the VMASS type will form part of the WIND Solar Wind and Suprathermal Ion experiment, the Soho mission, and the Advanced Composition Explorer.

  8. A design for a high resolution very-low-Q time-of flight diffractometer.

    SciTech Connect

    Hjelm, R. P.

    1998-09-29

    The design of a high resolution view low-Q time of flight diffractometer was motivated by the anticipated need to perform small-angle neutron scattering measurements at far lower momentum transfer and higher precision than currently available at either pulsed or steady state sources. In addition, it was recognized that flexibility in the configuration of the instrument and ease in which data is acquired are important. The design offers two configurations, a high intensity/very low Q geometry employing a focusing mirror and a medium to high Q-precision/low Q configuration using standard pinhole collimation geometry. The quality of the mirror optics is very important to the performance of the high intensity/very low Q configuration. We believe that the necessary technology exists to fabricate the high quality mirror optics required for the instrument.

  9. A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source.

    PubMed

    Stone, M B; Niedziela, J L; Abernathy, D L; DeBeer-Schmitt, L; Ehlers, G; Garlea, O; Granroth, G E; Graves-Brook, M; Kolesnikov, A I; Podlesnyak, A; Winn, B

    2014-04-01

    The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave-vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments are not exclusive and overlap significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

  10. A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source

    SciTech Connect

    Stone, Matthew B; Niedziela, Jennifer L; Abernathy, Douglas L; Debeer-Schmitt, Lisa M; Garlea, Vasile O; Granroth, Garrett E; Graves-Brook, Melissa K; Ehlers, Georg; Kolesnikov, Alexander I; Podlesnyak, Andrey A; Winn, Barry L

    2014-04-01

    The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments is not exclusive and overlaps significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

  11. Quantitative analysis of biomolecules by time-of-flight secondary-ion mass spectrometry: Fundamental considerations

    SciTech Connect

    Muddiman, D.C.; Nicola, A.J.; Proctor, A.

    1995-12-31

    Static Time-of-Flight Secondary-Ion Mass Spectrometry (TOF-SIMS) has been applied to investigate an extensive assortment of analytical systems; from semiconductors to DNA sequencing. Recently, the TOF-SIMS method has been successfully applied to real biological systems. This report focuses on some important aspects that must be taken into consideration when conducting measurements on biomaterials in order to observe the potential the TOF-SIMS method affords. The current data are presented using Cyclosporin A (CsA, 1202 Da) and cocaine (303 Da) as model compounds. CsA is observed in the TOF-SIMS mass spectrum predominately as a Ag-cationized species and cocaine as a protonated species; thus, they are complementary probe molecules.

  12. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography

    PubMed Central

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

    2015-01-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834

  13. Joint Temperature-Lasing Mode Compensation for Time-of-Flight LiDAR Sensors

    PubMed Central

    Alhashimi, Anas; Varagnolo, Damiano; Gustafsson, Thomas

    2015-01-01

    We propose an expectation maximization (EM) strategy for improving the precision of time of flight (ToF) light detection and ranging (LiDAR) scanners. The novel algorithm statistically accounts not only for the bias induced by temperature changes in the laser diode, but also for the multi-modality of the measurement noises that is induced by mode-hopping effects. Instrumental to the proposed EM algorithm, we also describe a general thermal dynamics model that can be learned either from just input-output data or from a combination of simple temperature experiments and information from the laser’s datasheet. We test the strategy on a SICK LMS 200 device and improve its average absolute error by a factor of three. PMID:26690445

  14. Development of picoseconds Time of Flight systems in Meson Test Beam Facility at Fermilab

    SciTech Connect

    Ronzhin, A.; Albrow, M.; Demarteau, M.; Los, S.; Malik, S.; Pronko, S.; Ramberg, E.; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez

    2010-11-01

    The goal of the work is to develop time of flight (TOF) system with about 10 picosecond time resolution in real beam line when start and stop counters separated by some distance. We name the distance as 'base' for the TOF. This 'real' TOF setup is different from another one when start and stop counters located next to each other. The real TOF is sensitive to beam momentum spread, beam divergence, etc. Anyway some preliminary measurements are useful with close placement of start and stop counter. We name it 'close geometry'. The work started about 2 years ago at Fermilab Meson Test Beam Facility (MTBF). The devices tested in 'close geometry' were Microchannel Plate Photomultipliers (MCP PMT) with Cherenkov radiators. TOF counters based on Silicon Photomultipliers (SiPms) with Cherenkov radiators also in 'close geometry' were tested. We report here new results obtained with the counters in the MTBF at Fermilab, including beam line data.

  15. Laser Time-of-Flight Mass Spectrometry for Future In Situ Planetary Missions

    NASA Technical Reports Server (NTRS)

    Getty, S. A.; Brinckerhoff, W. B.; Cornish, T.; Ecelberger, S. A.; Li, X.; Floyd, M. A. Merrill; Chanover, N.; Uckert, K.; Voelz, D.; Xiao, X.; Tawalbeh, R.; Glenar, D.; Elsila, J. E.; Callahan, M.

    2012-01-01

    Laser desorption/ionization time-of-flight mass spectrometry (LD-TOF-MS) is a versatile, low-complexity instrument class that holds significant promise for future landed in situ planetary missions that emphasize compositional analysis of surface materials. Here we describe a 5kg-class instrument that is capable of detecting and analyzing a variety of analytes directly from rock or ice samples. Through laboratory studies of a suite of representative samples, we show that detection and analysis of key mineral composition, small organics, and particularly, higher molecular weight organics are well suited to this instrument design. A mass range exceeding 100,000 Da has recently been demonstrated. We describe recent efforts in instrument prototype development and future directions that will enhance our analytical capabilities targeting organic mixtures on primitive and icy bodies. We present results on a series of standards, simulated mixtures, and meteoritic samples.

  16. High precision laser ranging by time-of-flight measurement of femtosecond pulses

    NASA Astrophysics Data System (ADS)

    Lee, Joohyung; Lee, Keunwoo; Lee, Sanghyun; Kim, Seung-Woo; Kim, Young-Jin

    2012-06-01

    Time-of-flight (TOF) measurement of femtosecond light pulses was investigated for laser ranging of long distances with sub-micrometer precision in the air. The bandwidth limitation of the photo-detection electronics used in timing femtosecond pulses was overcome by adopting a type-II nonlinear second-harmonic crystal that permits the production of a balanced optical cross-correlation signal between two overlapping light pulses. This method offered a sub-femtosecond timing resolution in determining the temporal offset between two pulses through lock-in control of the pulse repetition rate with reference to the atomic clock. The exceptional ranging capability was verified by measuring various distances of 1.5, 60 and 700 m. This method is found well suited for future space missions based on formation-flying satellites as well as large-scale industrial applications for land surveying, aircraft manufacturing and shipbuilding.

  17. Laser ranging by time-of-flight measurement of femtosecond light pulses

    NASA Astrophysics Data System (ADS)

    Kim, Young-Jin

    2014-04-01

    Time-of-flight (TOF) measurement of femtosecond light pulses was investigated for laser ranging of long distances with sub-micrometer precision in the air. The bandwidth limitation of the photo-detection electronics used in timing femtosecond pulses was overcome by adopting a type-II nonlinear second-harmonic crystal that permits producing the balanced optical cross-correlation signal between two overlapped light pulses. This method offered a sub-femtosecond timing resolution in determining the temporal offset between two pulses through lock-in control of the pulse repetition rate with reference to the atomic clock. The exceptional ranging capability was verified by measuring various distances from 1.5 m to 700 m. This method is found suited for terrestrial land surveying and space missions of formation-flying satellites.

  18. Recovering three-dimensional shape around a corner using ultrafast time-of-flight imaging

    NASA Astrophysics Data System (ADS)

    Velten, Andreas; Willwacher, Thomas; Gupta, Otkrist; Veeraraghavan, Ashok; Bawendi, Moungi G.; Raskar, Ramesh

    2012-03-01

    The recovery of objects obscured by scattering is an important goal in imaging and has been approached by exploiting, for example, coherence properties, ballistic photons or penetrating wavelengths. Common methods use scattered light transmitted through an occluding material, although these fail if the occluder is opaque. Light is scattered not only by transmission through objects, but also by multiple reflection from diffuse surfaces in a scene. This reflected light contains information about the scene that becomes mixed by the diffuse reflections before reaching the image sensor. This mixing is difficult to decode using traditional cameras. Here we report the combination of a time-of-flight technique and computational reconstruction algorithms to untangle image information mixed by diffuse reflection. We demonstrate a three-dimensional range camera able to look around a corner using diffusely reflected light that achieves sub-millimetre depth precision and centimetre lateral precision over 40 cm×40 cm×40 cm of hidden space.

  19. Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography

    NASA Astrophysics Data System (ADS)

    Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

    2015-10-01

    Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium.

  20. MONSTER: a time of flight spectrometer for β-delayed neutron emission measurements

    NASA Astrophysics Data System (ADS)

    Garcia, A. R.; Martínez, T.; Cano-Ott, D.; Castilla, J.; Guerrero, C.; Marín, J.; Martínez, G.; Mendoza, E.; Ovejero, M. C.; Reillo, E. M.; Santos, C.; Tera, F. J.; Villamarín, D.; Nolte, R.; Agramunt, J.; Algora, A.; Tain, J. L.; Banerjee, K.; Bhattacharya, C.; Pentillä, H.; Rinta-Antila, S.; Gorelov, D.

    2012-05-01

    The knowledge of the β-decay properties of nuclei contributes decisively to our understanding of nuclear phenomena: the β-delayed neutron emission of neutron rich nuclei plays an important role in the nucleosynthesis r-process and constitutes a probe for nuclear structure of very neutron rich nuclei providing information about the high energy part of the full beta strength (Sβ) function. In addition, β-delayed neutrons are essential for the control and safety of nuclear reactors. In order to determine the neutron energy spectra and emission probabilities from neutron precursors a MOdular Neutron time-of-flight SpectromeTER (MONSTER) has been proposed for the DESPEC experiment at the future FAIR facility. The design of MONSTER and status of its construction are reported in this work.

  1. Automated Gain Control Ion Funnel Trap for Orthogonal Time-of-Flight Mass Spectrometry

    PubMed Central

    Ibrahim, Yehia M.; Belov, Mikhail E.; Liyu, Andrei V.; Smith, Richard D.

    2009-01-01

    Time-of-flight mass spectrometry (TOF MS) is increasingly used in proteomics research. Herein, we report on the development and characterization of a TOF MS instrument with improved sensitivity equipped with an electrodynamic ion funnel trap (IFT) that employs an automated gain control (AGC) capability. The IFT-TOF MS was coupled to a reversed-phase capillary liquid chromatography (RPLC) separation and evaluated in experiments with complex proteolytic digests. When applied to a global tryptic digest of Shewanella oneidensis proteins, an order-of-magnitude increase in sensitivity compared to that of the conventional continuous mode of operation was achieved due to efficient ion accumulation prior to TOF MS analysis. As a result of this sensitivity improvement and related improvement in mass measurement accuracy, the number of unique peptides identified in the AGC-IFT mode was 5-fold greater than that obtained in the continuous mode. PMID:18512944

  2. Standardization of time-of-flight laser ionization mass spectrometry analysis of minerals

    NASA Astrophysics Data System (ADS)

    Dimov, S. S.; Chryssoulis, S. L.

    1998-03-01

    The standardization of the time-of-flight laser ionization mass spectrometry (TOF-LIMS) analysis of mineral surfaces is an important step towards providing reproducible quantitative data. This paper reports the search for experimental conditions and instrumental configurations that provide efficient ionization for all elements of the sample. For that purpose, an investigation of the neutral emission dynamics and the ion yields for the most important elements, as a function of laser power densities, the relative time delay between the ablation and postionization processes, and the sample matrix, was performed. In order to standardize the procedure, an empirical protocol was established, based on the use of optimized system parameters to monitor the ion yield from a library of standard reference samples.

  3. A miniature laser ablation time-of-flight mass spectrometer for in situ planetary exploration

    NASA Astrophysics Data System (ADS)

    Rohner, Urs; Whitby, James A.; Wurz, Peter

    2003-12-01

    We report the development and testing of a miniature mass spectrometer and ion source intended to be deployed on an airless planetary surface to measure the elemental and isotopic composition of rocks and soils. Our design concentrates at this stage on the proposed BepiColombo mission to the planet Mercury. The mass analyser is an axially symmetric reflectron time-of-flight design. The ion source utilizes a laser induced plasma, which is directly coupled into the mass analyser. Laser ablation gives high spatial resolution, and avoids the need for sample preparation. Our prototype instrument has a demonstrated mass resolution m/Dgrm (FWHM) in excess of 600 and a predicted dynamic range of better than four orders of magnitude. Isotopic fractionation effects are found to be minor. We estimate that a flight instrument would have a mass of 500 g (including all electronics), a volume of 650 cm3 and could operate on 3 W power.

  4. Probing nanoparticles and nanoparticle-conjugated biomolecules using time-of-flight secondary ion mass spectrometry.

    PubMed

    Kim, Young-Pil; Shon, Hyun Kyong; Shin, Seung Koo; Lee, Tae Geol

    2015-01-01

    Bio-conjugated nanoparticles have emerged as novel molecular probes in nano-biotechnology and nanomedicine and chemical analyses of their surfaces have become challenges. The time-of-flight (TOF) secondary ion mass spectrometry (SIMS) has been one of the most powerful surface characterization techniques for both nanoparticles and biomolecules. When combined with various nanoparticle-based signal enhancing strategies, TOF-SIMS can probe the functionalization of nanoparticles as well as their locations and interactions in biological systems. Especially, nanoparticle-based SIMS is an attractive approach for label-free drug screening because signal-enhancing nanoparticles can be designed to directly measure the enzyme activity. The chemical-specific imaging analysis using SIMS is also well suited to screen nanoparticles and nanoparticle-biomolecule conjugates in complex environments. This review presents some recent applications of nanoparticle-based TOF-SIMS to the chemical analysis of complex biological systems.

  5. Depth profiling and imaging capabilities of an ultrashort pulse laser ablation time of flight mass spectrometer

    PubMed Central

    Cui, Yang; Moore, Jerry F.; Milasinovic, Slobodan; Liu, Yaoming; Gordon, Robert J.; Hanley, Luke

    2012-01-01

    An ultrafast laser ablation time-of-flight mass spectrometer (AToF-MS) and associated data acquisition software that permits imaging at micron-scale resolution and sub-micron-scale depth profiling are described. The ion funnel-based source of this instrument can be operated at pressures ranging from 10−8 to ∼0.3 mbar. Mass spectra may be collected and stored at a rate of 1 kHz by the data acquisition system, allowing the instrument to be coupled with standard commercial Ti:sapphire lasers. The capabilities of the AToF-MS instrument are demonstrated on metal foils and semiconductor wafers using a Ti:sapphire laser emitting 800 nm, ∼75 fs pulses at 1 kHz. Results show that elemental quantification and depth profiling are feasible with this instrument. PMID:23020378

  6. On the numerical corrections of time-of-flight neutron powder diffraction data.

    SciTech Connect

    Avdeev, M.; Jorgensen, J.; Short, S.; Von Dreele, R.

    2007-08-01

    Time-of-flight neutron powder diffraction data for NIST Standard Reference Materials have been used to study the adequacy of the peak profile model obtained from a convolution of back-to-back exponentials with a pseudo-Voigt function that is widely used in Rietveld refinement. It is shown that, while the empirical models for d-spacing (wavelength) dependence of Gaussian and Lorentzian components of the pseudo-Voigt function and rise exponent are satisfactory, the behavior of the decay exponent and peak positions demonstrate significant deviations, which can be corrected by numerical methods. The practical side of this process as implemented in GSAS and FULLPROF and the effect of the corrections on the Rietveld analysis results are discussed.

  7. A novel principle for an ion mirror design in time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Scherer, S.; Altwegg, K.; Balsiger, H.; Fischer, J.; Jäckel, A.; Korth, A.; Mildner, M.; Piazza, D.; Reme, H.; Wurz, P.

    2006-03-01

    A novel design for a gridless two-stage ion mirror, or reflectron, for time-of-flight mass spectrometry (TOFMS) will be presented. The development of this novel design was driven by the stringent engineering requirements for the ion mirror's utilization by the reflectron time-of-flight (RTOF) sensor in the Rosetta orbiter spectrometer for ion and neutral analysis (ROSINA) instrument package of the Rosetta cometary mission launched by the European Space Agency in March 2004. The reflectron consists of ceramic and titanium alloy components joined by brazing and welding processes. The device serves as both the mechanical structure and as an ultra-high-vacuum (UHV) enclosure for the TOFMS system. The electrostatic fields of the reflectron are generated along two individually adjustable sections of a resistor helix applied to the inner surface of a ceramic cylinder. This design allows for increased homogeneity of the electrostatic fields, and minimizes fringe fields close to the cylindrical boundary of the reflectron structure. Thus, the usable inner diameter of ion flight path for a given outer diameter is maximized; a feature required by spacecraft constraints. An additional electrostatic lens in front of the reflectron allows the geometrical alteration of the shape of the ion beam, and its direction with regard to the ion optical axis. This makes it possible to switch the operation of the TOFMS system between a single-reflection and a triple-reflection mode, the latter using an additional ion mirror. Typically, mass resolutions of up to 5000 at full width at half maximum (FWHM) have been achieved in the triple-reflection mode for an overall sensor dimension of 1 m. Experimental results in the single-reflection mode and in the triple-reflection mode will be presented. Environmental constraints for space applications will also be discussed.

  8. C60 SIMS with a Hybrid-Quadrupole Orthogonal time-of-flight Mass Spectrometer

    PubMed Central

    Carado, Anthony; Passarelli, M. K.; Kozole, Joseph; Wingate, J. E.; Winograd, Nicholas; Loboda, A. V.

    2009-01-01

    A hybrid quadrupole orthogonal time-of-flight mass spectrometer optimized for MALDI and electrospray ionization has been equipped with a C60 cluster ion source. This configuration is shown to exhibit a number of characteristics that improve the performance of traditional time-of-flight secondary ion mass spectrometry (SIMS) experiments for the analysis of complex organic materials, and potentially, for chemical imaging. Specifically, the primary ion beam is operated as a continuous rather than a pulsed beam, resulting in up to 4 orders of magnitude greater ion fluence on the target. The secondary ions are extracted at very low voltage into 8 millitorr of N2 gas introduced for collisional focusing and cooling purposes. This extraction configuration is shown to yield secondary ions that rapidly lose memory of the mechanism of their birth, yielding tandem mass spectra that are identical for SIMS and MALDI. With implementation of ion trapping, the extraction efficiency is shown to be equivalent to that found in traditional TOF-SIMS machines. Examples are given, for a variety of substrates that illustrate mass resolution of 12,000–15,600 with mass range for inorganic compounds to m/z 40,000. Preliminary chemical mapping experiments show that with added sensitivity, imaging in the MS/MS mode of operation is straightforward. In general, the combination of MALDI and SIMS is shown to add capabilities to each technique, providing a robust platform for TOF-SIMS experiments that already exists in a large number of laboratories. PMID:18844371

  9. Characterization of a compact filament-driven multicusp ion source for low energy time-of-flight Rutherford backscattering spectrometry application

    NASA Astrophysics Data System (ADS)

    Dangtip, S.; Junphong, P.; Ano, V.; Lekprasert, B.; Suwannakachorn, D.; Thongnopparat, N.; Vilaithong, T.

    2004-05-01

    Because of the limited pulse height energy resolution of a detector, conventional Rutherford backscattering spectrometry (RBS) requires an energy of the incident α particle to be in the MeV region. At Chiang Mai University we have researched the possibility of utilizing a 280 keV nanosecond pulse of helium ions for RBS applications. We have chosen a compact filament-driven multicusp ion source of 2.6 cm in diameter and 8 cm in length being investigated for the time-of-flight RBS applications. In this article, we present the general ion source performance using helium, nitrogen, and argon for generating the discharge plasma. The general ion source characteristics have been measured and analyzed. The measurements also include the extractable ion current and the ion beam emittance. We have performed beam extraction calculations with a computer simulation code KOBRA. Results of the measurements and calculations will be presented and discussed.

  10. High mass resolution, high angular acceptance time-of-flight mass spectroscopy for planetary missions under the Planetary Instrument Definition and Development Program (PIDDP)

    NASA Technical Reports Server (NTRS)

    Young, David T.

    1991-01-01

    This final report covers three years and several phases of work in which instrumentation for the Planetary Instrument Definition and Development Program (PIDDP) were successfully developed. There were two main thrusts to this research: (1) to develop and test methods for electrostatically scanning detector field-of-views, and (2) to improve the mass resolution of plasma mass spectrometers to M/delta M approximately 25, their field-of-view (FOV) to 360 degrees, and their E-range to cover approximately 1 eV to 50 keV. Prototypes of two different approaches to electrostatic scanning were built and tested. The Isochronous time-of-flight (TOF) and the linear electric field 3D TOF devices were examined.

  11. Real-time 3D video utilizing a compressed sensing time-of-flight single-pixel camera

    NASA Astrophysics Data System (ADS)

    Edgar, Matthew P.; Sun, Ming-Jie; Gibson, Graham M.; Spalding, Gabriel C.; Phillips, David B.; Padgett, Miles J.

    2016-09-01

    Time-of-flight 3D imaging is an important tool for applications such as remote sensing, machine vision and autonomous navigation. Conventional time-of-flight three-dimensional imaging systems that utilize a raster scanned laser to measure the range of each pixel in the scene sequentially, inherently have acquisition times that scale directly with the resolution. Here we show a modified time-of-flight 3D camera employing structured illumination, which uses a visible camera to enable a novel compressed sensing technique, minimising the acquisition time as well as providing a high-resolution reflectivity map for image overlay. Furthermore, a quantitative assessment of the 3D imaging performance is provided.

  12. HYSPEC : A CRYSTAL TIME OF FLIGHT HYBRID SPECTROMETER FOR THE SPALLATION NEUTRON SOURCE.

    SciTech Connect

    SHAPIRO,S.M.; ZALIZNYAK,I.A.

    2002-12-30

    This document lays out a proposal by the Instrument Development Team (IDT) composed of scientists from leading Universities and National Laboratories to design and build a conceptually new high-flux inelastic neutron spectrometer at the pulsed Spallation Neutron Source (SNS) at Oak Ridge. This instrument is intended to supply users of the SNS and scientific community, of which the IDT is an integral part, with a platform for ground-breaking investigations of the low-energy atomic-scale dynamical properties of crystalline solids. It is also planned that the proposed instrument will be equipped with a polarization analysis capability, therefore becoming the first polarized beam inelastic spectrometer in the SNS instrument suite, and the first successful polarized beam inelastic instrument at a pulsed spallation source worldwide. The proposed instrument is designed primarily for inelastic and elastic neutron spectroscopy of single crystals. In fact, the most informative neutron scattering studies of the dynamical properties of solids nearly always require single crystal samples, and they are almost invariably flux-limited. In addition, in measurements with polarization analysis the available flux is reduced through selection of the particular neutron polarization, which puts even more stringent limits on the feasibility of a particular experiment. To date, these investigations have mostly been carried out on crystal spectrometers at high-flux reactors, which usually employ focusing Bragg optics to concentrate the neutron beam on a typically small sample. Construction at Oak Ridge of the high-luminosity spallation neutron source, which will provide intense pulsed neutron beams with time-averaged fluxes equal to those at medium-flux reactors, opens entirely new opportunities for single crystal neutron spectroscopy. Drawing upon experience acquired during decades of studies with both crystal and time-of-flight (TOF) spectrometers, the IDT has developed a conceptual

  13. Detectors

    DOEpatents

    Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore; Bounds, John Alan; Allander, Krag

    2002-01-01

    The apparatus and method provide techniques through which both alpha and beta emission determinations can be made simultaneously using a simple detector structure. The technique uses a beta detector covered in an electrically conducting material, the electrically conducting material discharging ions generated by alpha emissions, and as a consequence providing a measure of those alpha emissions. The technique also offers improved mountings for alpha detectors and other forms of detectors against vibration and the consequential effects vibration has on measurement accuracy.

  14. Alice in Wonderland syndrome

    PubMed Central

    2016-01-01

    Abstract Purpose of review: To summarize the literature on Alice in Wonderland syndrome (AIWS), a disorder characterized by distortions of visual perception, the body schema, and the experience of time. Recent findings: On the basis of 169 published case descriptions, the etiology of AIWS is divided into 8 main groups, with neurologic disorders affecting mostly adults and elderly patients and encephalitides affecting mostly patients aged ≤18 years. Symptoms of AIWS are also experienced in the general population, with up to 30% of adolescents reporting nonclinical symptoms. Summary: In clinical cases of AIWS, auxiliary investigations (including blood tests, EEG, and brain MRI) are strongly advised. Treatment should be directed at the suspected underlying condition, although reassurance that the symptoms themselves are not harmful seems to suffice in about 50% of the cases. International classifications such as the DSM and ICD should consider placing the syndrome on their research agenda. PMID:27347442

  15. The PERDaix detector

    NASA Astrophysics Data System (ADS)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman; Kirn, Thomas; Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhöver, Jens

    2012-12-01

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246×400×859 mm3, a geometrical acceptance of 32 cm2sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  16. Impulse responses of visible phototubes used in National Ignition Facility neutron time of flight diagnostics

    NASA Astrophysics Data System (ADS)

    Datte, P. S.; Eckart, M.; Moore, A. S.; Thompson, W.; Vergel de Dios, G.

    2016-11-01

    Neutron-induced visible scintillation in neutron time of flight (NToF) diagnostics at the National Ignition Facility (NIF) is measured with 40 mm single stage micro-channel plate photomultipliers and a 40 mm vacuum photodiode, outside the neutron line of sight. In NIF experiments with 14 MeV neutron yields above Y > 10 × 1015 these tubes are configured to deliver of order 1 nC of charge in the nominally 5 ns NToF into a 50 Ω load. We have examined a number of 40 mm tubes manufactured by Photek Ltd. of St. Leonards on Sea, UK, to determine possible changes in the instrument impulse response as a function of signal charge delivered in 1 ns. Precision NToF measurements at approximately 20 m require that we characterize changes in the impulse response moments to <40 ps for the first central moment and ˜2% rms for the square root of the second central moment with ˜500 ps value. Detailed results are presented for three different diode configurations.

  17. Facile time-of-flight methods for characterizing pulsed superfluid helium droplet beams

    SciTech Connect

    He, Yunteng; Zhang, Jie; Li, Yang; Freund, William M.; Kong, Wei

    2015-08-15

    We present two facile time-of-flight (TOF) methods of detecting superfluid helium droplets and droplets with neutral dopants. Without an electron gun and with only a heated filament and pulsed electrodes, the electron impact ionization TOF mass spectrometer can resolve ionized helium clusters such as He{sub 2}{sup +} and He{sub 4}{sup +}, which are signatures of superfluid helium droplets. Without ionizing any helium atoms, multiphoton non-resonant laser ionization of CCl{sub 4} doped in superfluid helium droplets at 266 nm generates complex cluster ions of dopant fragments with helium atoms, including (He){sub n}C{sup +}, (He){sub n}Cl{sup +}, and (He){sub n}CCl{sup +}. Using both methods, we have characterized our cryogenic pulsed valve—the Even-Lavie valve. We have observed a primary pulse with larger helium droplets traveling at a slower speed and a rebound pulse with smaller droplets at a faster speed. In addition, the pickup efficiency of dopant is higher for the primary pulse when the nozzle temperature is higher than 13 K, and the total time duration of the doped droplet pulse is only on the order of 20 μs. These results stress the importance of fast and easy characterization of the droplet beam for sensitive measurements such as electron diffraction of doped droplets.

  18. LSO background radiation as a transmission source using time of flight

    NASA Astrophysics Data System (ADS)

    Rothfuss, Harold; Panin, Vladimir; Moor, Andrew; Young, John; Hong, Inki; Michel, Christian; Hamill, James; Casey, Michael

    2014-09-01

    LSO scintillators (Lu2Sio5:Ce) have a background radiation which originates from the isotope Lu-176 that is present in natural occurring lutetium. The decay that occurs in this isotope is a beta decay that is in coincidence with cascade gamma emissions with energies of 307,202 and 88 keV. The coincidental nature of the beta decay with the gamma emissions allow for separation of emission data originating from a positron annihilation event from transmission type data from the Lu-176 beta decay. By using the time of flight information, and information of the chord length between two LSO pixels in coincidence as a result of a beta emission and emitted gamma, a second time window can be set to observe transmission events simultaneously to emission events. Using the time when the PET scanner is not actively acquiring positron emission data, a continuous blank can be acquired and used to reconstruct a transmission image. With this blank and the measured transmission data, a transmission image can be reconstructed. This reconstructed transmission image can be used to perform emission data corrections such as attenuation correction and scatter corrections or starting images for algorithms that estimate emission and attenuation simultaneously. It is observed that the flux of the background activity is high enough to create useful transmission images with an acquisition time of 10 min.

  19. Time-of-flights and traps: from the Histone Code to Mars*

    PubMed Central

    Swatkoski, Stephen; Becker, Luann; Evans-Nguyen, Theresa

    2011-01-01

    Two very different analytical instruments are featured in this perspective paper on mass spectrometer design and development. The first instrument, based upon the curved-field reflectron developed in the Johns Hopkins Middle Atlantic Mass Spectrometry Laboratory, is a tandem time-of-flight mass spectrometer whose performance and practicality are illustrated by applications to a series of research projects addressing the acetylation, deacetylation and ADP-ribosylation of histone proteins. The chemical derivatization of lysine-rich, hyperacetylated histones as their deuteroacetylated analogs enables one to obtain an accurate quantitative assessment of the extent of acetylation at each site. Chemical acetylation of histone mixtures is also used to determine the lysine targets of sirtuins, an important class of histone deacetylases (HDACs), by replacing the deacetylated residues with biotin. Histone deacetylation by sirtuins requires the co-factor NAD+, as does the attachment of ADP-ribose. The second instrument, a low voltage and low power ion trap mass spectrometer known as the Mars Organic Mass Analyzer (MOMA), is a prototype for an instrument expected to be launched in 2018. Like the tandem mass spectrometer, it is also expected to have applicability to environmental and biological analyses and, ultimately, to clinical care. PMID:20530839

  20. Liquid chromatography quadrupole time-of-flight mass spectrometry selective determination of ochratoxin A in wine.

    PubMed

    Rodríguez-Cabo, T; Rodríguez, I; Ramil, M; Cela, R

    2016-05-15

    The performance of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) for ochratoxin A (OTA) determination in wine is evaluated for the first time. Sample preparation was optimized to obtain quantitative recoveries at the same time that the efficiency of electrospray ionization (ESI) remained unaltered between sample extracts and calibration standards. Under final conditions, samples (20 mL) were concentrated using a reversed-phase solid-phase extraction (SPE) cartridge, followed by OTA elution with 1 mL of ethyl acetate. The absolute recoveries of the method, established against calibration standards, were 91-121% and 90-113% (without and with internal standard correction, respectively), for wines fortified at 3 concentration levels. The attained LOQ (0.05 ng mL(-1)) remained below the maximum permitted OTA concentration (2 ng mL(-1)) in dry wines. The method was applied to different samples, with OTA being found in some dessert wines at concentrations below 1 ng mL(-1). The ethyl ester of OTA (OTC) could be identified in the same wine samples from its accurate full product ion spectra.

  1. Measuring time-of-flight in an ultrasonic LPS system using generalized cross-correlation.

    PubMed

    Villladangos, José Manuel; Ureña, Jesús; García, Juan Jesús; Mazo, Manuel; Hernández, Alvaro; Jiménez, Ana; Ruíz, Daniel; De Marziani, Carlos

    2011-01-01

    In this article, a time-of-flight detection technique in the frequency domain is described for an ultrasonic local positioning system (LPS) based on encoded beacons. Beacon transmissions have been synchronized and become simultaneous by means of the DS-CDMA (direct-sequence code Division multiple access) technique. Every beacon has been associated to a 255-bit Kasami code. The detection of signal arrival instant at the receiver, from which the distance to each beacon can be obtained, is based on the application of the generalized cross-correlation (GCC), by using the cross-spectral density between the received signal and the sequence to be detected. Prior filtering to enhance the frequency components around the carrier frequency (40 kHz) has improved estimations when obtaining the correlation function maximum, which implies an improvement in distance measurement precision. Positioning has been achieved by using hyperbolic trilateration, based on the time differences of arrival (TDOA) between a reference beacon and the others.

  2. Implementation of Dipolar Resonant Excitation Collision Induced Dissociation with Ion Mobility/Time-of-Flight MS

    SciTech Connect

    Webb, Ian K.; Chen, Tsung-Chi; Danielson, William F.; Ibrahim, Yehia M.; Tang, Keqi; Anderson, Gordon A.; Smith, Richard D.

    2014-01-28

    Under and overfragmentation are significant hurdles to the data independent “bottom-up” approach to proteomics. Another challenge to the data independent approach is the convolution of fragments from different peptides that coelute in reverse-phase liquid chromatography/mass spectrometry (RPLC/MS). The ion mobility/collision induced dissociation/time-of flight mass spectrometry (IMS/CID/TOF MS) approach gives drift-time aligned fragment ions that have the same arrival time distributions as precursor ions, greatly aiding in fragment and peptide ion identification. We have modified an IMS/TOF MS platform to allow for resonant excitation CID experiments. Resonant excitation CID leads to highly efficient, mass-resolved fragmentation without additional excitation of product ions, alleviating the overfragmentation problem. The ability to apply resonant waveforms in mobility-resolved windows has been demonstrated with a peptide mixture yielding fragmentation over a range of mass-to-charge (m/z) ratios within a single IMS separation experiment.

  3. Facile time-of-flight methods for characterizing pulsed superfluid helium droplet beams.

    PubMed

    He, Yunteng; Zhang, Jie; Li, Yang; Freund, William M; Kong, Wei

    2015-08-01

    We present two facile time-of-flight (TOF) methods of detecting superfluid helium droplets and droplets with neutral dopants. Without an electron gun and with only a heated filament and pulsed electrodes, the electron impact ionization TOF mass spectrometer can resolve ionized helium clusters such as He2(+) and He4(+), which are signatures of superfluid helium droplets. Without ionizing any helium atoms, multiphoton non-resonant laser ionization of CCl4 doped in superfluid helium droplets at 266 nm generates complex cluster ions of dopant fragments with helium atoms, including (He)(n)C(+), (He)(n)Cl(+), and (He)(n)CCl(+). Using both methods, we have characterized our cryogenic pulsed valve—the Even-Lavie valve. We have observed a primary pulse with larger helium droplets traveling at a slower speed and a rebound pulse with smaller droplets at a faster speed. In addition, the pickup efficiency of dopant is higher for the primary pulse when the nozzle temperature is higher than 13 K, and the total time duration of the doped droplet pulse is only on the order of 20 μs. These results stress the importance of fast and easy characterization of the droplet beam for sensitive measurements such as electron diffraction of doped droplets.

  4. Context-aware fall detection using inertial sensors and time-of-flight transceivers.

    PubMed

    Shastry, Mahesh C; Asgari, Meysam; Wan, Eric A; Leitschuh, Joseph; Preiser, Nicholas; Folsom, Jon; Condon, John; Cameron, Michelle; Jacobs, Peter G

    2016-08-01

    Automatic detection of falls is important for enabling people who are older to safely live independently longer within their homes. Current automated fall detection systems are typically designed using inertial sensors positioned on the body that generate an alert if there is an abrupt change in motion. These inertial sensors provide no information about the context of the person being monitored and are prone to false positives that can limit their ongoing usage. We describe a fall-detection system consisting of a wearable inertial measurement unit (IMU) and an RF time-of-flight (ToF) transceiver that ranges with other ToF beacons positioned throughout a home. The ToF ranging enables the system to track the position of the person as they move around a home. We describe and show results from three machine learning algorithms that integrate context-related position information with IMU based fall detection to enable a deeper understanding of where falls are occurring and also to improve the specificity of fall detection. The beacons used to localize the falls were able to accurately track to within 0.39 meters of specific waypoints in a simulated home environment. Each of the three algorithms was evaluated with and without the context-based false alarm detection on simulated falls done by 3 volunteer subjects in a simulated home. False positive rates were reduced by 50% when including context.

  5. LSO background radiation as a transmission source using time of flight.

    PubMed

    Rothfuss, Harold; Panin, Vladimir; Moor, Andrew; Young, John; Hong, Inki; Michel, Christian; Hamill, James; Casey, Michael

    2014-09-21

    LSO scintillators (Lu2Sio5:Ce) have a background radiation which originates from the isotope Lu-176 that is present in natural occurring lutetium. The decay that occurs in this isotope is a beta decay that is in coincidence with cascade gamma emissions with energies of 307,202 and 88 keV. The coincidental nature of the beta decay with the gamma emissions allow for separation of emission data originating from a positron annihilation event from transmission type data from the Lu-176 beta decay. By using the time of flight information, and information of the chord length between two LSO pixels in coincidence as a result of a beta emission and emitted gamma, a second time window can be set to observe transmission events simultaneously to emission events. Using the time when the PET scanner is not actively acquiring positron emission data, a continuous blank can be acquired and used to reconstruct a transmission image. With this blank and the measured transmission data, a transmission image can be reconstructed. This reconstructed transmission image can be used to perform emission data corrections such as attenuation correction and scatter corrections or starting images for algorithms that estimate emission and attenuation simultaneously. It is observed that the flux of the background activity is high enough to create useful transmission images with an acquisition time of 10 min.

  6. Multiple-reflection time-of-flight mass spectrometry for in situ applications

    NASA Astrophysics Data System (ADS)

    Dickel, T.; Plaß, W. R.; Lang, J.; Ebert, J.; Geissel, H.; Haettner, E.; Jesch, C.; Lippert, W.; Petrick, M.; Scheidenberger, C.; Yavor, M. I.

    2013-12-01

    Multiple-reflection time-of-flight mass spectrometers (MR-TOF-MS) have recently been installed at different low-energy radioactive ion beam facilities. They are used as isobar separators with high ion capacity and as mass spectrometers with high mass resolving power and accuracy for short-lived nuclei. Furthermore, MR-TOF-MS have a huge potential for applications in other fields, such as chemistry, biology, medicine, space science, and homeland security. The development, commissioning and results of an MR-TOF-MS is presented, which serves as proof-of-principle to show that very high mass resolving powers (∼105) can be achieved in a compact device (length ∼30 cm). Based on this work, an MR-TOF-MS for in situ application has been designed. For the first time, this device combines very high mass resolving power (>105), mobility, and an atmospheric pressure inlet in one instrument. It will enable in situ measurements without sample preparation at very high mass accuracy. Envisaged applications of this mobile MR-TOF-MS are discussed.

  7. Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments

    NASA Astrophysics Data System (ADS)

    Hatarik, R.; Sayre, D. B.; Caggiano, J. A.; Phillips, T.; Eckart, M. J.; Bond, E. J.; Cerjan, C.; Grim, G. P.; Hartouni, E. P.; Knauer, J. P.; Mcnaney, J. M.; Munro, D. H.

    2015-11-01

    Neutron time-of-flight diagnostics have long been used to characterize the neutron spectrum produced by inertial confinement fusion experiments. The primary diagnostic goals are to extract the d + t → n + α (DT) and d + d → n + 3He (DD) neutron yields and peak widths, and the amount DT scattering relative to its unscattered yield, also known as the down-scatter ratio (DSR). These quantities are used to infer yield weighted plasma conditions, such as ion temperature (Tion) and cold fuel areal density. We report on novel methodologies used to determine neutron yield, apparent Tion, and DSR. These methods invoke a single temperature, static fluid model to describe the neutron peaks from DD and DT reactions and a spline description of the DT spectrum to determine the DSR. Both measurements are performed using a forward modeling technique that includes corrections for line-of-sight attenuation and impulse response of the detection system. These methods produce typical uncertainties for DT Tion of 250 eV, 7% for DSR, and 9% for the DT neutron yield. For the DD values, the uncertainties are 290 eV for Tion and 10% for the neutron yield.

  8. Matrix assisted laser desorption time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology.

    PubMed

    Angeletti, Silvia

    2016-09-06

    The microbiological management of patients with suspected bacterial infection includes the identification of the pathogen and the determination of the antibiotic susceptibility. These traditional approaches, based on the pure culture of the microorganism, require at least 36-48h. A new method, Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS), has been recently developed to profile bacterial proteins from whole cell extracts and obtain a bacterial fingerprint able to discriminate microorganisms from different genera and species. By whole cell-mass spectrometry, microbial identification can be achieved within minutes from cultured isolate, rather than traditional phenotypic or genotypic characterizations. From the year 2009 an explosion of applications of this technology has been observed with promising results. Several studies have been performed and showed that MALDI-TOF represents a reliable alternative method for rapid bacteria and fungi identification in clinical setting. A future area of expansion is represented by the application of MALDI-TOF technology to the antibiotic susceptibility test. In conclusion, the revision of the literature available up to date demonstrated that MALDI-TOF MS represents an innovative technology for the rapid and accurate identification of bacterial and fungal isolates in clinical settings. By an earlier microbiological diagnosis, MALDI-TOF MS contributes to a reduced mortality and hospitalization time of the patients and consequently has a significant impact on cost savings and public health.

  9. Multiplexed Ion Mobility Spectrometry - Orthogonal Time-Of-Flight Mass Spectrometry

    SciTech Connect

    Belov, Mikhail E.; Buschbach, Michael A.; Prior, David C.; Tang, Keqi; Smith, Richard D.

    2007-03-15

    Ion mobility spectrometry (IMS) coupled to orthogonal time-of-flight mass spectrometry (TOF) has shown significant promise for the characterization of complex biological mixtures. The enormous complexity of biological samples (e.g. from proteomics) and the need for both biological and technical analysis replicates imposes major challenges for multidimensional separation platforms in regard to both sensitivity and sample throughput. A major potential attraction of the IMS-TOF MS platform is separation speeds exceeding that of conventional condensed-phase separations by orders of magnitude. Known limitations of the IMS-TOF MS platforms that presently mitigate this attraction include the need for extensive signal averaging due to factors that include significant ion losses in the IMS-TOF interface and an ion utilization efficiency of less than ~1% with continuous ion sources (e.g. ESI). We have developed a new multiplexed ESI-IMS-TOF mass spectrometer that enables lossless ion transmission through the IMS-TOF as well as a utilization efficiency of >50% for ions from the ESI source. Initial results with a mixture of peptides show a ~10-fold increase in signal-to-noise ratio with the multiplexed approach compared to a signal averaging approach, with no reduction in either IMS or TOF MS resolution.

  10. Depth Errors Analysis and Correction for Time-of-Flight (ToF) Cameras.

    PubMed

    He, Ying; Liang, Bin; Zou, Yu; He, Jin; Yang, Jun

    2017-01-05

    Time-of-Flight (ToF) cameras, a technology which has developed rapidly in recent years, are 3D imaging sensors providing a depth image as well as an amplitude image with a high frame rate. As a ToF camera is limited by the imaging conditions and external environment, its captured data are always subject to certain errors. This paper analyzes the influence of typical external distractions including material, color, distance, lighting, etc. on the depth error of ToF cameras. Our experiments indicated that factors such as lighting, color, material, and distance could cause different influences on the depth error of ToF cameras. However, since the forms of errors are uncertain, it's difficult to summarize them in a unified law. To further improve the measurement accuracy, this paper proposes an error correction method based on Particle Filter-Support Vector Machine (PF-SVM). Moreover, the experiment results showed that this method can effectively reduce the depth error of ToF cameras to 4.6 mm within its full measurement range (0.5-5 m).

  11. Laser desorption time-of-flight mass spectrometry of ultraviolet photo-processed ices

    SciTech Connect

    Paardekooper, D. M. Bossa, J.-B.; Isokoski, K.; Linnartz, H.

    2014-10-01

    A new ultra-high vacuum experiment is described that allows studying photo-induced chemical processes in interstellar ice analogues. MATRI²CES - a Mass Analytical Tool to study Reactions in Interstellar ICES applies a new concept by combining laser desorption and time-of-flight mass spectrometry with the ultimate goal to characterize in situ and in real time the solid state evolution of organic compounds upon UV photolysis for astronomically relevant ice mixtures and temperatures. The performance of the experimental setup is demonstrated by the kinetic analysis of the different photoproducts of pure methane (CH₄) ice at 20 K. A quantitative approach provides formation yields of several new species with up to four carbon atoms. Convincing evidence is found for the formation of even larger species. Typical mass resolutions obtained range from M/ΔM ~320 to ~400 for CH₄ and argon, respectively. Additional tests show that the typical detection limit (in monolayers) is ⩽0.02 ML, substantially more sensitive than the regular techniques used to investigate chemical processes in interstellar ices.

  12. Development and characterization of an aircraft aerosol time-of-flight mass spectrometer.

    PubMed

    Pratt, Kerri A; Mayer, Joseph E; Holecek, John C; Moffet, Ryan C; Sanchez, Rene O; Rebotier, Thomas P; Furutani, Hiroshi; Gonin, Marc; Fuhrer, Katrin; Su, Yongxuan; Guazzotti, Sergio; Prather, Kimberly A

    2009-03-01

    Vertical and horizontal profiles of atmospheric aerosols are necessary for understanding the impact of air pollution on regional and global climate. To gain further insight into the size-resolved chemistry of individual atmospheric particles, a smaller aerosol time-of-flight mass spectrometer (ATOFMS) with increased data acquisition capabilities was developed for aircraft-based studies. Compared to previous ATOFMS systems, the new instrument has a faster data acquisition rate with improved ion transmission and mass resolution, as well as reduced physical size and power consumption, all required advances for use in aircraft studies. In addition, real-time source apportionment software allows the immediate identification and classification of individual particles to guide sampling decisions while in the field. The aircraft (A)-ATOFMS was field-tested on the ground during the Study of Organic Aerosols in Riverside, CA (SOAR) and aboard an aircraft during the Ice in Clouds Experiment-Layer Clouds (ICE-L). Initial results from ICE-L represent the first reported aircraft-based single-particle dual-polarity mass spectrometry measurements and provide an increased understanding of particle mixing state as a function of altitude. Improved ion transmission allows for the first single-particle detection of species out to approximately m/z 2000, an important mass range for the detection of biological aerosols and oligomeric species. In addition, high time resolution measurements of single-particle mixing state are demonstrated and shown to be important for airborne studies where particle concentrations and chemistry vary rapidly.

  13. Development of a compact laser-based single photon ionization time-of-flight mass spectrometer

    NASA Astrophysics Data System (ADS)

    Tonokura, Kenichi; Kanno, Nozomu; Yamamoto, Yukio; Yamada, Hiroyuki

    2010-02-01

    We have developed a compact, laser-based, single photon ionization time-of-flight mass spectrometer (SPI-TOF-MS) for on-line monitoring of trace organic species. To obtain the mass spectrum, we use a nearly fragmentation-free SPI technique with 10.5 eV (118 nm) vacuum ultraviolet laser pulses generated by frequency tripling of the third harmonic of an Nd:YAG laser. The instrument can be operated in a linear TOF-MS mode or a reflectron TOF-MS mode in the coaxial design. We designed ion optics to optimize detection sensitivity and mass resolution. For data acquisition, the instrument is controlled using LabVIEW control software. The total power requirement for the vacuum unit, control electronics unit, ion optics, and detection system is approximately 100 W. We achieve a detection limit of parts per billion by volume (ppbv) for on-line trace analysis of several organic compounds. A mass resolution of 800 at about 100 amu is obtained for reflectron TOF-MS mode in a 0.35 m long instrument. The application of on-line monitoring of diesel engine exhaust was demonstrated.

  14. Time-of-Flight Mass Measurements for Nuclear Processes in Neutron Star Crusts

    NASA Astrophysics Data System (ADS)

    Estradé, A.; Matoš, M.; Schatz, H.; Amthor, A. M.; Bazin, D.; Beard, M.; Becerril, A.; Brown, E. F.; Cyburt, R.; Elliot, T.; Gade, A.; Galaviz, D.; George, S.; Gupta, S. S.; Hix, W. R.; Lau, R.; Lorusso, G.; Möller, P.; Pereira, J.; Portillo, M.; Rogers, A. M.; Shapira, D.; Smith, E.; Stolz, A.; Wallace, M.; Wiescher, M.

    2011-10-01

    We present results from time-of-flight nuclear mass measurements at the National Superconducting Cyclotron Laboratory that are relevant for neutron star crust models. The masses of 16 neutron-rich nuclei in the scandium-nickel range were determined simultaneously, with the masses of V61, Cr63, Mn66, and Ni74 measured for the first time with mass excesses of -30.510(890)MeV, -35.280(650)MeV, -36.900(790)MeV, and -49.210(990)MeV, respectively. With these results the locations of the dominant electron capture heat sources in the outer crust of accreting neutron stars that exhibit super bursts are now experimentally constrained. We find the experimental Q value for the Fe66→Mn66 electron capture to be 2.1 MeV (2.6σ) smaller than predicted, resulting in the transition occurring significantly closer to the neutron star surface.

  15. Experimental evaluation of a simple lesion detection task with time-of-flight PET

    NASA Astrophysics Data System (ADS)

    Surti, S.; Karp, J. S.

    2009-01-01

    A new generation of high-performance, time-of-flight (TOF) PET scanners have recently been developed. In earlier works, the gain with TOF information was derived as a reduction of noise in the reconstructed image, or essentially a gain in scanner sensitivity. These derivations were applicable to analytical reconstruction techniques and 2D PET imaging. In this work, we evaluate the gain measured in the clinically relevant task of lesion detection with TOF information in fully 3D PET scanners using iterative reconstruction algorithms. We performed measurements in a fully 3D TOF PET scanner using spherical lesions in uniform, cylindrical phantom. Lesion detectability was estimated for 10 mm diameter lesions using a non-prewhitening matched filter signal-to-noise-ratio (NPW SNR) as the metric. Our results show that the use of TOF information leads to increased lesion detectability, which is achieved with less number of iterations of the reconstruction algorithm. These phantom results indicate that clinically, TOF PET will allow reduced scan times and improved lesion detectability, especially in large patients.

  16. Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments

    SciTech Connect

    Hatarik, R. Sayre, D. B.; Caggiano, J. A.; Phillips, T.; Eckart, M. J.; Bond, E. J.; Cerjan, C.; Grim, G. P.; Hartouni, E. P.; Mcnaney, J. M.; Munro, D. H.; Knauer, J. P.

    2015-11-14

    Neutron time-of-flight diagnostics have long been used to characterize the neutron spectrum produced by inertial confinement fusion experiments. The primary diagnostic goals are to extract the d + t → n + α (DT) and d + d → n + {sup 3}He (DD) neutron yields and peak widths, and the amount DT scattering relative to its unscattered yield, also known as the down-scatter ratio (DSR). These quantities are used to infer yield weighted plasma conditions, such as ion temperature (T{sub ion}) and cold fuel areal density. We report on novel methodologies used to determine neutron yield, apparent T{sub ion}, and DSR. These methods invoke a single temperature, static fluid model to describe the neutron peaks from DD and DT reactions and a spline description of the DT spectrum to determine the DSR. Both measurements are performed using a forward modeling technique that includes corrections for line-of-sight attenuation and impulse response of the detection system. These methods produce typical uncertainties for DT T{sub ion} of 250 eV, 7% for DSR, and 9% for the DT neutron yield. For the DD values, the uncertainties are 290 eV for T{sub ion} and 10% for the neutron yield.

  17. Exploiting sparsity in time-of-flight range acquisition using a single time-resolved sensor.

    PubMed

    Kirmani, Ahmed; Colaço, Andrea; Wong, Franco N C; Goyal, Vivek K

    2011-10-24

    Range acquisition systems such as light detection and ranging (LIDAR) and time-of-flight (TOF) cameras operate by measuring the time difference of arrival between a transmitted pulse and the scene reflection. We introduce the design of a range acquisition system for acquiring depth maps of piecewise-planar scenes with high spatial resolution using a single, omnidirectional, time-resolved photodetector and no scanning components. In our experiment, we reconstructed 64 × 64-pixel depth maps of scenes comprising two to four planar shapes using only 205 spatially-patterned, femtosecond illuminations of the scene. The reconstruction uses parametric signal modeling to recover a set of depths present in the scene. Then, a convex optimization that exploits sparsity of the Laplacian of the depth map of a typical scene determines correspondences between spatial positions and depths. In contrast with 2D laser scanning used in LIDAR systems and low-resolution 2D sensor arrays used in TOF cameras, our experiment demonstrates that it is possible to build a non-scanning range acquisition system with high spatial resolution using only a standard, low-cost photodetector and a spatial light modulator.

  18. Development of a portable time-of-flight membrane inlet mass spectrometer for environmental analysis

    NASA Astrophysics Data System (ADS)

    White, A. J.; Blamire, M. G.; Corlett, C. A.; Griffiths, B. W.; Martin, D. M.; Spencer, S. B.; Mullock, S. J.

    1998-02-01

    The benefits of on-site analysis of environmental pollutants are well known, with such techniques increasing sample throughput and reducing the overall cost of pollution level monitoring. This article describes a transportable time-of-flight (TOF) mass spectrometer, based upon a converging, annular TOF (CAT) arrangement. The instrument, the transportable CAT or T-CAT is battery powered and self-contained. The vacuum chamber is never vented and is kept at a very low pressure, even during analysis. Sample gases are admitted to the mass spectrometer via a membrane inlet system. Data collection and analysis are accomplished via a portable PC. The T-CAT is capable of detection limits approaching those of more conventional, nonportable design. The device shows reasonable linearity over wide concentration ranges. Initial results indicate that the T-CAT will be capable of use in a wide range of applications, particularly for environmental monitoring. This article describes the features of the T-CAT, and presents initial results from the membrane inlet/T-CAT system.

  19. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    PubMed Central

    Huang, Yunguang; Li, Jinxu; Tang, Bin; Zhu, Liping; Hou, Keyong; Li, Haiyang

    2015-01-01

    A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear. PMID:26587023

  20. Improved streamlines and time-of-flight for streamline simulation on irregular grids

    NASA Astrophysics Data System (ADS)

    Hægland, H.; Dahle, H. K.; Eigestad, G. T.; Lie, K.-A.; Aavatsmark, I.

    2007-04-01

    Streamline methods have shown to be effective for reservoir simulation. For a regular grid, it is common to use the semi-analytical Pollock's method to obtain streamlines and time-of-flight coordinates (TOF). The usual way of handling irregular grids is by trilinear transformation of each grid cell to a unit cube together with a linear flux interpolation scaled by the Jacobian. The flux interpolation allows for fast integration of streamlines, but is inaccurate even for uniform flow. To improve the tracing accuracy, we introduce a new interpolation method, which we call corner-velocity interpolation. Instead of interpolating the velocity field based on discrete fluxes at cell edges, the new method interpolates directly from reconstructed point velocities given at the corner points in the grid. This allows for reproduction of uniform flow, and eliminates the influence of cell geometries on the velocity field. Using several numerical examples, we demonstrate that the new method is more accurate than the standard tracing methods.

  1. Simultaneous reconstruction of activity and attenuation in time-of-flight PET.

    PubMed

    Rezaei, Ahmadreza; Defrise, Michel; Bal, Girish; Michel, Christian; Conti, Maurizio; Watson, Charles; Nuyts, Johan

    2012-12-01

    In positron emission tomography (PET) and single photon emission tomography (SPECT), attenuation correction is necessary for quantitative reconstruction of the tracer distribution. Previously, several attempts have been made to estimate the attenuation coefficients from emission data only. These attempts had limited success, because the problem does not have a unique solution, and severe and persistent "cross-talk" between the estimated activity and attenuation distributions was observed. In this paper, we show that the availability of time-of-flight (TOF) information eliminates the cross-talk problem by destroying symmetries in the associated Fisher information matrix. We propose a maximum-a-posteriori reconstruction algorithm for jointly estimating the attenuation and activity distributions from TOF PET data. The performance of the algorithm is studied with 2-D simulations, and further illustrated with phantom experiments and with a patient scan. The estimated attenuation image is robust to noise, and does not suffer from the cross-talk that was observed in non-TOF PET. However, some constraining is still mandatory, because the TOF data determine the attenuation sinogram only up to a constant offset.

  2. Time-of-flight electron energy loss spectroscopy using TM110 deflection cavities.

    PubMed

    Verhoeven, W; van Rens, J F M; van Ninhuijs, M A W; Toonen, W F; Kieft, E R; Mutsaers, P H A; Luiten, O J

    2016-09-01

    We demonstrate the use of two TM110 resonant cavities to generate ultrashort electron pulses and subsequently measure electron energy losses in a time-of-flight type of setup. The method utilizes two synchronized microwave cavities separated by a drift space of 1.45 m. The setup has an energy resolution of 12 ± 2 eV FWHM at 30 keV, with an upper limit for the temporal resolution of 2.7 ± 0.4 ps. Both the time and energy resolution are currently limited by the brightness of the tungsten filament electron gun used. Through simulations, it is shown that an energy resolution of 0.95 eV and a temporal resolution of 110 fs can be achieved using an electron gun with a higher brightness. With this, a new method is provided for time-resolved electron spectroscopy without the need for elaborate laser setups or expensive magnetic spectrometers.

  3. Time-of-flight electron energy loss spectroscopy using TM110 deflection cavities

    PubMed Central

    Verhoeven, W.; van Rens, J. F. M.; van Ninhuijs, M. A. W.; Toonen, W. F.; Kieft, E. R.; Mutsaers, P. H. A.; Luiten, O. J.

    2016-01-01

    We demonstrate the use of two TM110 resonant cavities to generate ultrashort electron pulses and subsequently measure electron energy losses in a time-of-flight type of setup. The method utilizes two synchronized microwave cavities separated by a drift space of 1.45 m. The setup has an energy resolution of 12 ± 2 eV FWHM at 30 keV, with an upper limit for the temporal resolution of 2.7 ± 0.4 ps. Both the time and energy resolution are currently limited by the brightness of the tungsten filament electron gun used. Through simulations, it is shown that an energy resolution of 0.95 eV and a temporal resolution of 110 fs can be achieved using an electron gun with a higher brightness. With this, a new method is provided for time-resolved electron spectroscopy without the need for elaborate laser setups or expensive magnetic spectrometers. PMID:27704035

  4. Depth Errors Analysis and Correction for Time-of-Flight (ToF) Cameras

    PubMed Central

    He, Ying; Liang, Bin; Zou, Yu; He, Jin; Yang, Jun

    2017-01-01

    Time-of-Flight (ToF) cameras, a technology which has developed rapidly in recent years, are 3D imaging sensors providing a depth image as well as an amplitude image with a high frame rate. As a ToF camera is limited by the imaging conditions and external environment, its captured data are always subject to certain errors. This paper analyzes the influence of typical external distractions including material, color, distance, lighting, etc. on the depth error of ToF cameras. Our experiments indicated that factors such as lighting, color, material, and distance could cause different influences on the depth error of ToF cameras. However, since the forms of errors are uncertain, it’s difficult to summarize them in a unified law. To further improve the measurement accuracy, this paper proposes an error correction method based on Particle Filter-Support Vector Machine (PF-SVM). Moreover, the experiment results showed that this method can effectively reduce the depth error of ToF cameras to 4.6 mm within its full measurement range (0.5–5 m). PMID:28067767

  5. Time-of-flight mass measurements for nuclear processes in neutron star crusts

    SciTech Connect

    Estrade, Alfredo; Matos, M.; Schatz, Hendrik; Amthor, A. M.; Bazin, D.; Beard, Mary; Becerril, A.; Brown, Edward; Elliot, T; Gade, A.; Galaviz, D.; George, S.; Gupta, Sanjib; Hix, William Raphael; Lau, Rita; Moeller, Peter; Pereira, J.; Portillo, M.; Rogers, A. M.; Shapira, Dan; Smith, E.; Stolz, A.; Wallace, M.; Wiescher, Michael

    2011-01-01

    The location of electron capture heat sources in the crust of accreting neutron stars depends on the masses of extremely neutron-rich nuclei. We present first results from a new implementation of the time-of-flight technique to measure nuclear masses of rare isotopes at the National Supercon- ducting Cyclotron Laboratory. The masses of 16 neutron-rich nuclei in the Sc Ni element range were determined simultaneously, improving the accuracy compared to previous data in 12 cases. The masses of 61V, 63Cr, 66Mn, and 74Ni were measured for the first time with mass excesses of 30.510(890) MeV, 35.280(650) MeV, 36.900(790) MeV, and 49.210(990) MeV, respectively. With the measurement of the 66Mn mass, the location of the two dominant heat sources in the outer crust of accreting neutron stars, which exhibit so called superbursts, is now experimentally constrained. We find that the location of the 66Fe 66Mn electron capture transition occurs sig- nificantly closer to the surface than previously assumed because our new experimental Q-value is 2.1 MeV smaller than predicted by the FRDM mass model. The results also provide new insights into the structure of neutron-rich nuclei around N = 40.

  6. Precise pulsed time-of-flight laser range finder for industrial distance measurements

    NASA Astrophysics Data System (ADS)

    Kilpelä, Ari; Pennala, Riku; Kostamovaara, Juha

    2001-04-01

    A pulsed time-of-flight laser range finder with a 1 GHz avalanche photo diode (APD) receiver and a laser pulser with ˜35 ps pulse width has been developed and tested. The receiver channel is constructed using a silicon ASIC chip and a commercially available silicon APD placed on a hybrid ceramic susbstrate. The laser pulser utilizes a single heterostructure laser operating in Q-switching mode. It is shown that the single-shot precision of the complete laser range finder is ˜2.1 mm (σ value) at best. The nonaccuracy in the distance range of 0.5-34.5 m was ˜±2 mm excluding errors caused by the statistical variations and long-term instability. The single-shot precision is clearly better than the single-shot precision of the earlier laser range finders with ˜100-200 MHz bandwidths. Also, two types of optics, coaxial and paraxial, were tested. The linearity of the coaxial optics was better, especially with a long (4 m) receiver fiber. Some possible applications of the laser range finder utilizing ps level pulses are, for example, fast three-dimensional vision in industrial environments and structure analysis of materials.

  7. In-home hierarchical posture classification with a time-of-flight 3D sensor.

    PubMed

    Diraco, Giovanni; Leone, Alessandro; Siciliano, Pietro

    2014-01-01

    A non-invasive technique for posture classification suitable to be used in several in-home scenarios is proposed and preliminary validation results are presented. 3D point cloud sequences were acquired using a single time-of-flight sensor working in a privacy preserving modality and they were processed with a low power embedded PC. In order to satisfy different application requirements (e.g. covered distance range, processing speed and discrimination capabilities), a twofold discrimination approach was investigated in which features were hierarchically arranged from coarse to fine by exploiting both topological and volumetric representations. The topological representation encoded the intrinsic topology of the body's shape using a skeleton-based structure, thus guaranteeing invariance to scale, rotations and postural changes and achieving a high level of detail with a moderate computational cost. On the other hand, using the volumetric representation features were described in terms of 3D cylindrical histograms working within a wider range of distances in a faster way and also guaranteeing good invariance properties. The discrimination capabilities were evaluated in four different real-home scenarios related with the fields of ambient assisted living and homecare, namely "dangerous event detection", "anomalous behaviour detection", "activities recognition" and "natural human-ambient interaction". For each mentioned scenario, the discrimination capabilities were evaluated in terms of invariance to viewpoint changes, representation capabilities and classification performance, achieving promising results. The two feature representation approaches exhibited complementary characteristics showing high reliability with classification rates greater than 97%.

  8. Fast fingerprinting of arson accelerants by proton transfer reaction time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Whyte, Christopher; Wyche, Kevin P.; Kholia, Mitesh; Ellis, Andrew M.; Monks, Paul S.

    2007-06-01

    Current techniques for the forensic analysis of fire debris as a means to detect the presence of arson accelerants normally use off-line sampling with the collection of accelerant vapours on activated charcoal strips and further pre-chemistry prior to analysis. An alternative method for the direct detection of arson accelerants that requires no sample pre-treatment is described here. The analysis uses proton transfer reaction mass spectrometry (PTR-MS), incorporating a time-of-flight mass spectrometer for rapid multichannel compound detection. It is demonstrated that using PTR-MS volatile organic compound (VOC) fingerprints of a given fire accelerant can be collected by simple head space analysis of accelerant burned materials. Using a set of the four most common arson accelerants and four common household building materials, characteristic VOC fingerprints are shown to provide successful identification of the accelerant used to burn each material. There is the potential to develop this methodology for the rapid screening of large numbers of samples.

  9. Acoustic tweezers via sub–time-of-flight regime surface acoustic waves

    PubMed Central

    Collins, David J.; Devendran, Citsabehsan; Ma, Zhichao; Ng, Jia Wei; Neild, Adrian; Ai, Ye

    2016-01-01

    Micrometer-scale acoustic waves are highly useful for refined optomechanical and acoustofluidic manipulation, where these fields are spatially localized along the transducer aperture but not along the acoustic propagation direction. In the case of acoustic tweezers, such a conventional acoustic standing wave results in particle and cell patterning across the entire width of a microfluidic channel, preventing selective trapping. We demonstrate the use of nanosecond-scale pulsed surface acoustic waves (SAWs) with a pulse period that is less than the time of flight between opposing transducers to generate localized time-averaged patterning regions while using conventional electrode structures. These nodal positions can be readily and arbitrarily positioned in two dimensions and within the patterning region itself through the imposition of pulse delays, frequency modulation, and phase shifts. This straightforward concept adds new spatial dimensions to which acoustic fields can be localized in SAW applications in a manner analogous to optical tweezers, including spatially selective acoustic tweezers and optical waveguides. PMID:27453940

  10. Bayesian Time-of-Flight for Realtime Shape, Illumination and Albedo.

    PubMed

    Adam, Amit; Dann, Christoph; Yair, Omer; Mazor, Shai; Nowozin, Sebastian

    2016-05-12

    We propose a computational model for shape, illumination and albedo inference in a pulsed time-of-flight (TOF) camera. In contrast to TOF cameras based on phase modulation, our camera enables general exposure profiles. This results in added flexibility and requires novel computational approaches. To address this challenge we propose a generative probabilistic model that accurately relates latent imaging conditions to observed camera responses. While principled, realtime inference in the model turns out to be infeasible, and we propose to employ efficient non-parametric regression trees to approximate the model outputs. As a result we are able to provide, for each pixel, at video frame rate, estimates and uncertainty for depth, effective albedo, and ambient light intensity. These results we present are state-of-the-art in depth imaging. The flexibility of our approach allows us to easily enrich our generative model. We demonstrate this by extending the original single-path model to a two-path model, capable of describing some multipath effects. The new model is seamlessly integrated in the system at no additional computational cost. Our work also addresses the important question of optimal exposure design in pulsed TOF systems. Finally, for benchmark purposes and to obtain realistic empirical priors of multipath and insights into this phenomena, we propose a physically accurate simulation of multipath phenomena.

  11. Multi-capillary-column proton-transfer-reaction time-of-flight mass spectrometry.

    PubMed

    Ruzsanyi, Veronika; Fischer, Lukas; Herbig, Jens; Ager, Clemes; Amann, Anton

    2013-11-05

    Proton-transfer-reaction time-of-flight mass-spectrometry (PTR-TOFMS) exhibits high selectivity with a resolution of around 5000 m/Δm. While isobars can be separated with this resolution, discrimination of isomeric compounds is usually not possible. The coupling of a multi-capillary column (MCC) with a PTR-TOFMS overcomes these problems as demonstrated in this paper for the ketone isomers 3-heptanone and 2-methyl-3-hexanone and for different aldehydes. Moreover, fragmentation of compounds can be studied in detail which might even improve the identification. LODs for compounds tested are in the range of low ppbv and peak positions of the respective separated substances show good repeatability (RSD of the peak positions <3.2%). Due to its special characteristics, such as isothermal operation, compact size, the MCC setup is suitable to be installed inside the instrument and the overall retention time for a complete spectrum is only a few minutes: this allows near real-time measurements in the optional MCC mode. In contrast to other methods that yield additional separation, such as the use of pre-cursor ions other than H3O(+), this method yields additional information without increasing complexity.

  12. Rapid identification of triphenylmethane dyes by ion mobility time-of-flight mass spectrometry.

    PubMed

    Sysoev, Alexey A; Poteshin, Sergey S; Chernyshev, Denis M; Sysoev, Alexander A

    2016-01-01

    An ion mobility time-of-flight mass spectrometry (IM-TOFMS)-based method has been preliminarily investigated for the identification of triphenylmethane ballpoint pen dyes on paper. The dyes were sampled from one-year-old ballpoint pen ink entries. The entries were written on paper documents stored in the dark in a bookcase. Sample solutions were prepared by extraction of dyes in a vial. Basic violet 2, Methyl violet 6B, Methyl violet 2B and Crystal violet were characterized by IM-TOFMS. Since the ballpoint ink dyes contain ionic compounds, the studied compounds were expected to form stable peaks in the atmospheric pressure drift tube ion mobility spectrometry, and this was experimentally verified. The studied dyes produce [M - Cl](+) ions in electrospray and form stable individual mass-selective reduced mobility peaks. The values of the characteristic reduced mobility are: 1.187 cm(2)/(V·s) for Basic violet 2 (m/z 330.20), 1.165 cm(2)/(V·s) for Methyl violet 6B (m/z 344.21), 1.156 cm(2)/(V·s) for Methyl violet 2B (m/z 358.23), 1.123 cm(2)/(V·s) for Crystal violet (m/z 372.24). IM-TOFMS is expected to be a promising tool for fast and reliable analysis of dyes in complex matrixes.

  13. Laser desorption time-of-flight mass spectrometry of vacuum UV photo-processed methanol ice

    NASA Astrophysics Data System (ADS)

    Paardekooper, D. M.; Bossa, J.-B.; Linnartz, H.

    2016-07-01

    Context. Methanol in the interstellar medium mainly forms upon sequential hydrogenation of solid CO. With typical abundances of up to 15% (with respect to water) it is an important constituent of interstellar ices where it is considered as a precursor in the formation of large and complex organic molecules (COMs), e.g. upon vacuum UV (VUV) photo-processing or exposure to cosmic rays. Aims: This study aims at detecting novel complex organic molecules formed during the VUV photo-processing of methanol ice in the laboratory using a technique more sensitive than regular surface diagnostic tools. In addition, the formation kinetics of the main photo-products of methanol are unravelled for an astronomically relevant temperature (20 K) and radiation dose. Methods: The VUV photo-processing of CH3OH ice is studied by applying laser desorption post-ionisation time-of-flight mass spectrometry (LDPI TOF-MS), and analysed by combining molecule-specific fragmentation and desorption features. Results: The mass spectra correspond to fragment ions originating from a number of previously recorded molecules and from new COMs, such as the series (CO)xH, with x = 3 and y < 3x-1, to which prebiotic glycerin belongs. The formation of these large COMs has not been reported in earlier photolysis studies and suggests that such complex species may form in the solid state under interstellar conditions.

  14. Multi-capillary-column proton-transfer-reaction time-of-flight mass spectrometry☆

    PubMed Central

    Ruzsanyi, Veronika; Fischer, Lukas; Herbig, Jens; Ager, Clemes; Amann, Anton

    2013-01-01

    Proton-transfer-reaction time-of-flight mass-spectrometry (PTR-TOFMS) exhibits high selectivity with a resolution of around 5000 m/Δm. While isobars can be separated with this resolution, discrimination of isomeric compounds is usually not possible. The coupling of a multi-capillary column (MCC) with a PTR-TOFMS overcomes these problems as demonstrated in this paper for the ketone isomers 3-heptanone and 2-methyl-3-hexanone and for different aldehydes. Moreover, fragmentation of compounds can be studied in detail which might even improve the identification. LODs for compounds tested are in the range of low ppbv and peak positions of the respective separated substances show good repeatability (RSD of the peak positions <3.2%). Due to its special characteristics, such as isothermal operation, compact size, the MCC setup is suitable to be installed inside the instrument and the overall retention time for a complete spectrum is only a few minutes: this allows near real-time measurements in the optional MCC mode. In contrast to other methods that yield additional separation, such as the use of pre-cursor ions other than H3O+, this method yields additional information without increasing complexity. PMID:24119758

  15. Lattice thermal expansion effects in pure and doped cordierite by time-of-flight neutron diffraction

    SciTech Connect

    Predecki, P.K.; Haas, J.; Faber, J. Jr.; Hitterman, R.L.

    1985-10-01

    The thermal expansion behavior of pure, Ge-doped and Li-doped hexagonal cordierites with respective compositions: 2Mg0 2Al2O3 5SiO2, 2Mg0 2Al2O3 4SiO2 GeO2, and 2Mg0 (2+x)Al2O3 (5-2x)SiO2 xLi2O with x = .174, was investigated using time-of-flight neutron powder diffraction at temperatures from 22 to 750C in vacuum. The data were refined in space group P6/mcc using the Rietveld method. The lattice thermal expansion curves of all 3 samples were quite similar. The negative c axis expansion is asociated with (1) displacement of the T2 cations generally toward the c axis channels and (2) changes in the distortion of the coupled T1/M tetrahedra/octahedra in the structure. Both contributions were present in all 3 samples but the first was more dominant in the Ge doped sample. The nature and origin of the distortions in T1 and M are discussed.

  16. Impulse responses of visible phototubes used in National Ignition Facility neutron time of flight diagnostics.

    PubMed

    Datte, P S; Eckart, M; Moore, A S; Thompson, W; Vergel de Dios, G

    2016-11-01

    Neutron-induced visible scintillation in neutron time of flight (NToF) diagnostics at the National Ignition Facility (NIF) is measured with 40 mm single stage micro-channel plate photomultipliers and a 40 mm vacuum photodiode, outside the neutron line of sight. In NIF experiments with 14 MeV neutron yields above Y > 10 × 10(15) these tubes are configured to deliver of order 1 nC of charge in the nominally 5 ns NToF into a 50 Ω load. We have examined a number of 40 mm tubes manufactured by Photek Ltd. of St. Leonards on Sea, UK, to determine possible changes in the instrument impulse response as a function of signal charge delivered in 1 ns. Precision NToF measurements at approximately 20 m require that we characterize changes in the impulse response moments to <40 ps for the first central moment and ∼2% rms for the square root of the second central moment with ∼500 ps value. Detailed results are presented for three different diode configurations.

  17. Probing the oligomeric structure of an enzyme by electrospray ionization time-of-flight mass spectrometry.

    PubMed

    Fitzgerald, M C; Chernushevich, I; Standing, K G; Whitman, C P; Kent, S B

    1996-07-09

    Electrospray ionization time-of-flight (ESI-TOF) mass spectrometry was used to study the quaternary structure of 4-oxalocrotonate tautomerase (EC 5.3.2; 4OT), and four analogues prepared by total chemical synthesis. Wild-type 4OT is a hexamer of 62 amino acid subunits and contains no cysteine residues. The analogues were: (desPro1)4OT, a truncated construct in which Pro1 was deleted; (Cpc1)4OT in which Pro1 was replaced with cyclopentane carboxylate; a derivative [Met(O)45]4OT in which Met45 was oxidized to the sulfoxide; and an analogue (Nle45)4OT in which Met45 was replaced with norleucine. ESI of (Nle45)4OT, (Cpc1)4OT, and 4OT from solution conditions under which the native enzyme was fully active (5 mM ammonium bicarbonate buffer, pH 7.5) gave the intact hexamer as the major species detected by TOF mass spectrometry. In contrast, analysis of [Met(O)45]4OT and (desPro1)4OT under similar conditions yielded predominantly monomer ions. The ESI-TOF measurements were consistent with structural data obtained from circular dichroism spectroscopy. In the context of kinetic data collected for 4OT and these analogues, ESI-TOF mass spectrometry also provided important evidence for the structural and mechanistic significance of the catalytically important Pro1 residue in 4OT.

  18. Higher-Pressure Ion Funnel Trap Interface for Orthogonal Time-of-Flight Mass Spectrometry

    PubMed Central

    Ibrahim, Yehia; Belov, Mikhail E.; Tolmachev, Aleksey V.; Prior, David C.; Smith, Richard D.

    2008-01-01

    A combined electrodynamic ion funnel and ion trap coupled to an orthogonal acceleration (oa)-time-of-flight mass spectrometer (oa-TOF MS) was developed and characterized. The ion trap was incorporated through the use of added terminal electrodynamic ion funnel electrodes enabling control over the axial DC gradient in the trap section. The ion trap operates efficiently at a pressure of 1 Torr, and measurements indicate a maximum charge capacity of ~3×107 charges. An order of magnitude increase in sensitivity was observed in the analysis of low concentration peptides mixtures with oa-TOF MS in the trapping mode as compared to the continuous regime. A signal increase in the trapping mode was accompanied by reduction in the background chemical noise, due to more efficient desolvation of e.g., solvent related clusters. Controlling the ion trap ejection time was found to result in efficient removal of singly charged species and improving signal-to-noise ratio (S/N) for the multiply charged analytes. PMID:17850113

  19. Probing the oligomeric structure of an enzyme by electrospray ionization time-of-flight mass spectrometry.

    PubMed Central

    Fitzgerald, M C; Chernushevich, I; Standing, K G; Whitman, C P; Kent, S B

    1996-01-01

    Electrospray ionization time-of-flight (ESI-TOF) mass spectrometry was used to study the quaternary structure of 4-oxalocrotonate tautomerase (EC 5.3.2; 4OT), and four analogues prepared by total chemical synthesis. Wild-type 4OT is a hexamer of 62 amino acid subunits and contains no cysteine residues. The analogues were: (desPro1)4OT, a truncated construct in which Pro1 was deleted; (Cpc1)4OT in which Pro1 was replaced with cyclopentane carboxylate; a derivative [Met(O)45]4OT in which Met45 was oxidized to the sulfoxide; and an analogue (Nle45)4OT in which Met45 was replaced with norleucine. ESI of (Nle45)4OT, (Cpc1)4OT, and 4OT from solution conditions under which the native enzyme was fully active (5 mM ammonium bicarbonate buffer, pH 7.5) gave the intact hexamer as the major species detected by TOF mass spectrometry. In contrast, analysis of [Met(O)45]4OT and (desPro1)4OT under similar conditions yielded predominantly monomer ions. The ESI-TOF measurements were consistent with structural data obtained from circular dichroism spectroscopy. In the context of kinetic data collected for 4OT and these analogues, ESI-TOF mass spectrometry also provided important evidence for the structural and mechanistic significance of the catalytically important Pro1 residue in 4OT. PMID:8692908

  20. Charge state separation for protein applications using a quadrupole time-of-flight mass spectrometer.

    PubMed

    Chernushevich, I V; Fell, L M; Bloomfield, N; Metalnikov, P S; Loboda, A V

    2003-01-01

    A novel method for separating ions according to their charge state using a quadrupole time-of-flight mass spectrometer is presented. The benefits of charge state separation are particularly apparent in protein identification applications at low femtomole concentration levels, where in conventional TOF MS spectra peptide ions are often lost in a sea of chemical noise. When doubly and triply charged tryptic peptide ions need to be filtered from singly charged background ions, the latter are suppressed by two to three orders of magnitude, while from 10-50% of multiply charged ions remain. The suppression of chemical noise reduces the need for chromatography and can make this experimental approach the electrospray equivalent of conventional MALDI peptide maps. If unambiguous identification cannot be achieved, MS/MS experiments are performed on the precursor ions identified through charge separation, while the previously described Q2-trapping duty cycle enhancement is tuned for approximately 1.4 of the precursor m/z to enhance intensities of ions with m/z values above that of the precursor. The resulting product ion spectra contain few fragments of impurities and provide quick and unambiguous identification through database search. The multiple charge separation technique requires minimal tuning and may become a useful tool for analysis of complex mixtures.