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Sample records for atmospheric cherenkov detectors

  1. Future water Cherenkov detectors

    SciTech Connect

    Bergevin, Marc

    2015-05-15

    In these proceedings a review of the current proposed large-scale Warer Cherenkov experiments is given. An argument is made that future water Cherenkov detectors would benefit in the investment in neutron detection technology. A brief overview will be given of proposed water Cherenkov experiments such as HYPER-K and MEMPHYS and other R and D experiments to demonstrate neutron capture in water Cherenkov detectors. Finally, innovation developed in the context of the now defunct LBNE Water R and D option to improve Water Cherenkov technology will be described.

  2. The CLAS Cherenkov detector

    SciTech Connect

    G. Adams; V. Burkert; R. Carl; T. Carstens; V. Frolov; L. Houghtlin; G. Jacobs; M. Kossov; M. Klusman; B. Kross; M. Onuk; J. Napolitano; J. W. Price; C. Riggs; Y. Sharabian; A. Stavinsky; L. C. Smith; W. A. Stephens; P. Stoler; W. Tuzel; K. Ullrich; A. Vlassovc; A. Weisenberger; M. Witkowski; B. Wojtekhowski; P. F. Yergin; C. Zorn

    2001-06-01

    The design, construction, and performance of the CLAS Cerenkov threshold gas detector at Jefferson Lab is described. The detector consists of 216 optical modules. Each module consists of 3 adjustable mirrors, of lightweight composite construction, a Winston light collecting cone, a 5-inch photomultiplier tube, and specially designed magnetic shielding.

  3. Experimental study of the atmospheric neutrino backgrounds for p{yields}e{sup +}{pi}{sup 0} searches in water Cherenkov detectors

    SciTech Connect

    Mine, S.; Casper, D.; Kropp, W.; Smy, M.; Sobel, H.; Vagins, M.; Alcaraz, J. L.; Andringa, S.; Espinal, X.; Fernandez, E.; Jover, G.; Nova, F.; Rodriguez, A.; Sanchez, F.; Aoki, S.; Asakura, K.; Hara, T.; Moriguchi, Y.; Sekiguchi, M.; Suzuki, A.

    2008-02-01

    The atmospheric neutrino background for proton decay via p{yields}e{sup +}{pi}{sup 0} in ring imaging water Cherenkov detectors is studied with an artificial accelerator neutrino beam for the first time. In total, 3.14x10{sup 5} neutrino events corresponding to about 10 megaton-years of atmospheric neutrino interactions were collected by a 1000 ton water Cherenkov detector (KT). The KT charged-current single {pi}{sup 0} production data are well reproduced by simulation programs of neutrino and secondary hadronic interactions used in the Super-Kamiokande (SK) proton decay search. The obtained p{yields}e{sup +}{pi}{sup 0} background rate by the KT data for SK from the atmospheric neutrinos whose energies are below 3 GeV is 1.63{sub -0.33}{sup +0.42}(stat){sub -0.51}{sup +0.45}(syst)(megaton-year){sup -1}. This result is also relevant to possible future, megaton-scale water Cherenkov detectors.

  4. Development of high refractive index Cherenkov detectors

    NASA Astrophysics Data System (ADS)

    Nazzal, Samah Suheil

    High refractive index materials have been investigated for use as Cherenkov media in order to develop a Cherenkov detector with a lower energy threshold. Several materials were surveyed and cubic zirconium was selected for further study. Samples of cubic zirconium were prepared and mated with photomultiplier tubes to form Cherenkov detectors. These detectors were tested using radioactive sources and muons in the laboratory and using protons at the Indiana Cyclotron in order to determine the Cherenkov light yield and to investigate contamination of the Cherenkov signal by scintillation. The results of the experimental tests were analyzed and compared to detailed numerical simulations. It was found that while some scintillation light was produced by ionizing particles in the cubic zirconium, Cherenkov light was detected at levels that make cubic zirconium usable as a Cherenkov detector. During this investigation, it was discovered that while the Cherenkov light signal was prompt with a rapid decay time, the scintillation light signal was slower both in rise time and in decay. This discovery offers the possibility to distinguish the Cherenkov and Scintillation signals.

  5. The BRAHMS ring imaging Cherenkov detector

    NASA Astrophysics Data System (ADS)

    Debbe, R.; Jørgensen, C. E.; Olness, J.; Yin, Z.

    2007-01-01

    A Ring Imaging Cherenkov detector built for the BRAHMS experiment at the Brookhaven RHIC is described. This detector has a high index of refraction gas radiator. Cherenkov light is focused on a photo-multiplier based photon detector with a large spherical mirror. The combination of momentum and ring radius measurement provides particle identification from 2.5 to 35 GeV/ c for pions and kaons and well above 40 GeV/ c for protons during runs that had the radiator index of refraction set at n-1=1700×10-6.

  6. Metamaterials for Cherenkov Radiation Based Particle Detectors

    SciTech Connect

    Tyukhtin, A. V.; Schoessow, P.; Kanareykin, A.; Antipov, S.

    2009-01-22

    Measurement of Cherenkov radiation (CR) has long been a useful technique for charged particle detection and beam diagnostics. We are investigating metamaterials engineered to have refractive indices tailored to enhance properties of CR that are useful for particle detectors and that cannot be obtained using conventional media. Cherenkov radiation in dispersive media with a large refractive index differs significantly from the same effect in conventional detector media, like gases or aerogel. The radiation pattern of CR in dispersive metamaterials presents lobes at very large angles with respect to particle motion. Moreover, the frequency and particle velocity dependence of the radiated energy can differ significantly from CR in a conventional dielectric medium.

  7. Detection of atmospheric Cherenkov radiation using solar heliostat mirrors

    NASA Astrophysics Data System (ADS)

    Ong, R. A.; Bhattacharya, D.; Covault, C. E.; Dixon, D. D.; Gregorich, D. T.; Hanna, D. S.; Oser, S.; Québert, J.; Smith, D. A.; Tümer, O. T.; Zych, A. D.

    1996-10-01

    There is considerable interest world-wide in developing large area atmospheric Cherenkov detectors for ground-based gamma-ray astronomy. This interest stems, in large part, from the fact that the gamma-ray energy region between 20 and 250 GeV is unexplored by any experiment. Atmospheric Cherenkov detectors offer a possible way to explore this region, but large photon collection areas are needed to achieve low energy thresholds. We are developing an experiment using the heliostat mirrors of a solar power plant as the primary collecting element. As part of this development, we built a detector using four heliostat mirrors, a secondary Fresnel lens, and a fast photon detection system. In November 1994, we used this detector to record atmospheric Cherenkov radiation produced by cosmic ray particles showering in the atmosphere. The detected rate of cosmic ray events was consistent with an energy threshold near 1 TeV. The data presented here represent the first detection of atmospheric Cherenkov radiation using solar heliostats viewed from a central tower.

  8. Cherenkov detector for beam quality measurement

    NASA Astrophysics Data System (ADS)

    Orfanelli, S.

    2016-07-01

    A new detector to measure the machine induced background at larger radii has been developed and installed in the CMS experiment at the LHC. It consists of forty modules, each comprising a quartz bar read out by a photomultiplier tube. Since Cherenkov radiation is emitted in a forward cone around the charged particle trajectory, these detectors can distinguish between the arrival directions of the machine induced background and the collision products. The back-end electronics consists of a uTCA readout with excellent time resolution. The installation in the CMS is described and first commissioning measurements with the LHC beams in Run II are presented.

  9. The endcap Cherenkov ring imaging detector at SLD

    SciTech Connect

    Abe, K.; Hasegawa, K.; Hawegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H.; Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dolinsky, S.

    1995-05-01

    The authors present the Cherenkov Ring Imaging Detector in the endcap regions of the SLD detector and report initial performance. The endcap CRID was completed and commissioned in 1993 and is fully operational for the 1994 run. First Cherenkov rings have been observed. The endcap CRID detectors and fluid systems are described and initial operational experience is discussed.

  10. Measurement of the Muon Atmospheric Production Depth with the Water Cherenkov Detectors of the Pierre Auger Observatory

    SciTech Connect

    Molina Bueno, Laura

    2015-09-01

    Ultra-high-energy cosmic rays (UHECR) are particles of uncertain origin and composition, with energies above 1 EeV (1018 eV or 0.16 J). The measured flux of UHECR is a steeply decreasing function of energy. The largest and most sensitive apparatus built to date to record and study cosmic ray Extensive Air Showers (EAS) is the Pierre Auger Observatory. The Pierre Auger Observatory has produced the largest and finest amount of data ever collected for UHECR. A broad physics program is being carried out covering all relevant topics of the field. Among them, one of the most interesting is the problem related to the estimation of the mass composition of cosmic rays in this energy range. Currently the best measurements of mass are those obtained by studying the longitudinal development of the electromagnetic part of the EAS with the Fluorescence Detector. However, the collected statistics is small, specially at energies above several tens of EeV. Although less precise, the volume of data gathered with the Surface Detector is nearly a factor ten larger than the fluorescence data. So new ways to study composition with data collected at the ground are under investigation. The subject of this thesis follows one of those new lines of research. Using preferentially the time information associated with the muons that reach the ground, we try to build observables related to the composition of the primaries that initiated the EAS. A simple phenomenological model relates the arrival times with the depths in the atmosphere where muons are produced. The experimental confirmation that the distributions of muon production depths (MPD) correlate with the mass of the primary particle has opened the way to a variety of studies, of which this thesis is a continuation, with the aim of enlarging and improving its range of applicability. We revisit the phenomenological model which is at the root of the analysis and discuss a new way to improve some aspects of the model. We carry

  11. Cherenkov neutron detector for fusion reaction and runaway electron diagnostics

    SciTech Connect

    Cheon, MunSeong Kim, Junghee

    2015-08-15

    A Cherenkov-type neutron detector was newly developed and neutron measurement experiments were performed at Korea Superconducting Tokamak Advanced Research. It was shown that the Cherenkov neutron detector can monitor the time-resolved neutron flux from deuterium-fueled fusion plasmas. Owing to the high temporal resolution of the detector, fast behaviors of runaway electrons, such as the neutron spikes, could be observed clearly. It is expected that the Cherenkov neutron detector could be utilized to provide useful information on runaway electrons as well as fusion reaction rate in fusion plasmas.

  12. Using Fast Photosensors in Water Cherenkov Neutrino Detectors

    NASA Astrophysics Data System (ADS)

    Xin, Tian

    2013-04-01

    The next generation of neutrino experiments will require massive and/or high resolution detectors to reach the sensitivity needed to measure CP violation in the lepton sector and the neutrino mass hierarchy. The Large-Area Picosecond Photo Detector (LAPPD) Collaboration is developing new methods to fabricate 8in-square thin planar micro channel plate photosensors, which have shown to have excellent spatial and timing resolution. By using these devices in Water Cherenkov detector, people could significantly improve the background rejection and the vertex reconstruction. We present preliminary results on the reconstruction capabilities for single particles in Water Cherenkov detectors.

  13. Multiplexed gas Cherenkov detector for reaction-history measurements

    SciTech Connect

    Mack, J. M.; Caldwell, S. E.; Evans, S. C.; Sedillo, T. J.; Wilson, D. C.; Young, C. S.; Horsfield, C. J.; Griffith, R. L.; Lerche, R. A.

    2006-10-15

    A diagnostic is being designed for the National Ignition Facility, using fusion gamma rays to measure highly time-resolved bang times and deuterium-tritium (d-t) interaction rates for imploding inertial fusion capsules. As a complement to neutron-based methods, gas Cherenkov detectors were chosen for this purpose because of proven ultrahigh bandwidth, thresholding versatility, and minimal time-of-flight dispersion. Gas Cherenkov detector prototypes, involving streak cameras and fast photomultiplier, microchannel plate detectors, are being tested using d-t implosions at the Omega Laser Facility. The possibility of simultaneous streak camera and photomultiplier, microchannel plate recordings of a source in one gas Cherenkov detector instrument is advantageous for reasons of independent measurement and extended reaction-history coverage. A multiplexed gas Cherenkov detector system was demonstrated successfully using electron pulses produced by the Idaho State University linear electron accelerator. A reaction-history diagnostic scheme composed of several types of detectors is proposed. The detectors considered reflect current and improving technology that allows coverage over a significant range of a reaction history generated from National Ignition Facility implosions.

  14. Fast timing and trigger Cherenkov detector for collider experiments

    NASA Astrophysics Data System (ADS)

    Grigoryev, V. A.; Kaplin, V. A.; Karavicheva, T. L.; Konevskikh, A. S.; Kurepin, A. B.; Loginov, V. A.; Melikyan, Yu A.; Morozov, I. V.; Reshetin, A. I.; Serebryakov, D. V.; Shabanov, A. I.; Slupecki, M.; Trzaska, W. H.; Tykmanov, E. M.

    2016-02-01

    Analysis of fast timing and trigger Cherenkov detector's design for its use in collider experiments is presented. Several specific requirements are taken into account - necessity of the radiator's placement as close to the beam pipe as possible along with the requirement of gapless (solid) radiator's design. Characteristics of the Cherenkov detector's laboratory prototype obtained using a pion beam at the CERN Proton Synchrotron are also presented, showing the possibility of obtaining sufficiently high geometrical efficiency along with good enough time resolution (50 ps sigma).

  15. Large size SiPM matrix for Imaging Atmospheric Cherenkov Telescopes applications

    NASA Astrophysics Data System (ADS)

    Ambrosi, G.; Corti, D.; Ionica, M.; Manea, C.; Mariotti, M.; Rando, R.; Reichardt, I.; Schultz, C.

    2016-07-01

    SiPM photo detectors are nowadays commonly used in many applications. For large size telescopes like MAGIC or the future Large Size Telescope (LST) of the Cherenkov Telescope Array (CTA) project, a pixel size of some square centimeters is needed. An analog amplifier and sum stage was built and characterized. A large and compact SiPM matrix prototype, with the associated focusing optics, was assembled into a monolithic light detector with an active area of 3 cm2. The performance of the electronics is tailored for Imaging Atmospheric Cherenkov Telescopes (IACT) applications, with fast signal and adequate signal-to-noise (S/N) ratio.

  16. A ring imaging Cherenkov detector for CLAS12

    SciTech Connect

    Montgomery, Rachel A.

    2013-12-01

    The energy increase of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) to 12 GeV promises to greatly extend the physics reach of its experiments. This will include an upgrade of the CEBAF Large Acceptance Spectrometer (CLAS) to CLAS12, offering unique possibilities to study internal nucleon dynamics. For this excellent hadron identification over the full kinematical range of 3–8 GeV/c is essential. This will be achieved by the installation of a Ring Imaging CHerenkov (RICH) detector. A novel hybrid imaging design incorporating mirrors, aerogel radiators and Hamamatsu H8500 multianode photomultiplier tubes is proposed. Depending on the incident particle track angle, Cherenkov light will either be imaged directly or after two reflections and passes through the aerogel. The detector design is described, along with preliminary results on individual detector components tests and from recent testbeam studies.

  17. Catching GRBs with atmospheric Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Gilmore, R. C.; Primack, J. R.; Bouvier, A.; Otte, A. N.

    2011-08-01

    Fermi has shown GRBs to be a source of >10 GeV photons. We present an estimate of the detection rate of GRBs with a next generation Cherenkov telescope. Our predictions are based on the observed properties of GRBs detected by Fermi, combined with the spectral properties and redshift determinations for the bursts population by instruments operating at lower energies. While detection of VHE emission from GRBs has eluded ground-based instruments thus far, our results suggest that ground-based detection may be within reach of the proposed Cherenkov Telescope Array (CTA), albeit with a low rate, 0.25-0.5/yr. Such a detection would help constrain the emission mechanism of gamma-ray emission from GRBs. Photons at these energies from distant GRBs are affected by the UV-optical background light, and a ground-based detection could also provide a valuable probe of the Extragalactic Background Light (EBL) in place at high redshift.

  18. Silicon photomultiplier based photon detector module as a detector of Cherenkov photons

    NASA Astrophysics Data System (ADS)

    Korpar, Samo; Chagani, Hassan; Dolenec, Rok; Križan, Peter; Pestotnik, Rok; Stanovnik, Aleš

    2010-11-01

    We have constructed and tested a module, consisting of 64 (= 8×8) Hamamatsu MPPC S10362-11-100P silicon photomultipliers, for position sensitive detection of Cherenkov photons. Suitable light concentrators were produced to increase the efficiency and to improve the signal to noise ratio. The results of our measurements indicate that the performance of such a Cherenkov counter with aerogel radiator could meet the requirements of particle identification at the foreseen upgraded Belle detector.

  19. The water Cherenkov detectors of the HAWC Observatory

    NASA Astrophysics Data System (ADS)

    Longo, Megan; Mostafa, Miguel

    2012-10-01

    The High Altitude Water Cherenkov (HAWC) observatory is a very high-energy gamma-ray detector which is currently under construction at 4100 m in Sierra Negra, Mexico. The observatory will be composed of an array of 300 Water Cherenkov Detectors (WCDs). Each WCD consists of a 5 m tall by 7.3 m wide steel tank containing a hermetically sealed plastic bag, called a bladder, which is filled with 200,000 liters of purified water. The detectors are each equipped with four upward-facing photomultiplier tubes (PMTs), anchored to the bottom of the bladder. At Colorado State University (CSU) we have the only full-size prototype outside of the HAWC site. It serves as a testbed for installation and operation procedures for the HAWC observatory. The WCD at CSU has been fully operational since March 2011, and has several components not yet present at the HAWC site. In addition to the four HAWC position PMTs, our prototype has three additional PMTs, including one shrouded (dark) PMT. We also have five scintillator paddles, four buried underneath the HAWC position PMTs, and one freely moving paddle above the volume of water. These extra additions will allow us to work on muon reconstruction with a single WCD. We will describe the analysis being done with the data taken with the CSU prototype, its impact on the HAWC detector, and future plans for the prototype.

  20. The Hadron Blind Ring Imaging Cherenkov Detector

    NASA Astrophysics Data System (ADS)

    Blatnik, Marie; Zajac, Stephanie; Hemmick, Tom

    2013-10-01

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

  1. Cherenkov Counters

    SciTech Connect

    Barbero, Marlon

    2012-04-19

    When a charged particle passes through an optically transparent medium with a velocity greater than the phase velocity of light in that medium, it emits prompt photons, called Cherenkov radiation, at a characteristic polar angle that depends on the particle velocity. Cherenkov counters are particle detectors that make use of this radiation. Uses include prompt particle counting, the detection of fast particles, the measurement of particle masses, and the tracking or localization of events in very large, natural radiators such as the atmosphere, or natural ice fields, like those at the South Pole in Antarctica. Cherenkov counters are used in a number of different fields, including high energy and nuclear physics detectors at particle accelerators, in nuclear reactors, cosmic ray detectors, particle astrophysics detectors and neutrino astronomy, and in biomedicine for labeling certain biological molecules.

  2. Silicon photomultiplier as a detector of Cherenkov photons

    NASA Astrophysics Data System (ADS)

    Korpar, S.; Dolenec, R.; Hara, K.; Iijima, T.; Križan, P.; Mazuka, Y.; Pestotnik, R.; Stanovnik, A.; Yamaoka, M.

    2008-09-01

    A novel photon detector—i.e. the silicon photomultiplier—whose main advantage over conventional photomultiplier tubes is the operation in high magnetic fields, has been tested as a photon detector in a proximity focusing RICH with aerogel radiator. This type of RICH counter is proposed for the upgrade of the Belle detector at the KEK B-factory. Recently produced silicon photomultipliers show less noise and have larger size, which are important issues for a large area photon detector. We measured the single photon pulse height distribution, the timing resolution and the position sensitivity for different silicon photomultipliers (Hamamatsu MPPC HC025, HC050, and HC100). The silicon photomultipliers were then used to detect Cherenkov photons emitted by cosmic ray particles in a proximity focusing aerogel RICH. Various light guides were investigated in order to increase the detection efficiency.

  3. Signal Temporal Profile of a Water Cherenkov Detector

    NASA Astrophysics Data System (ADS)

    Salazar, H.; Martinez, O.; Cotzomi, J.; Moreno, E.; Villaseñor, L.

    2003-07-01

    The suggested existence of temporal structure in the signals of extensive air showers (EAS) for energies greater than 1017 eV at core distances of about 500 m, and its correlation with important parameters of EASs has stimulated us to study this structure for showers with lower energies in an Auger water Cherenkov detector(WCD). Preliminary analysis of experimental data on the widths of signals in a WCD and their correlation with other parameters of the signal are presented. The detector was triggered by the EAS-BUAP array which operates in the region of 1014 - 1016 eV. The distance of the WCD to the EAS core is larger than 30 m.

  4. About a Gadolinium-doped Water Cherenkov LAGUNA Detector

    SciTech Connect

    Labarga, Luis

    2010-11-24

    Water Cherenkov (wC) detectors are extremely powerful apparatuses for scientific research. Nevertheless they lack of neutron tagging capabilities, which translates, mainly, into an inability to identify the anti-matter nature of the reacting incoming anti-neutrino particles. A solution was proposed by R. Beacon and M. Vagins back in 2004: by dissolving in the water a compound with nucleus with very large cross section for neutron capture like the Gadolinium, with a corresponding emission of photons of enough energy to be detected, they can tag thermal neutrons with an efficiency larger than 80%. In this talk we detail the technique and its implications in the measurement capabilities and, as well, the new backgrounds induced. We discuss the improvement on their physics program, also for the case of LAGUNA type detectors. We comment shortly the status of the pioneering R and D program of the Super-Kamiokande Collaboration towards dissolving a Gadolinium compound in its water.

  5. Study of solar activity by measuring cosmic rays with a water Cherenkov detector

    NASA Astrophysics Data System (ADS)

    Bahena Bias, Angélica; Villaseñor, Luis

    2011-04-01

    We report on an indirect study of solar activity by using the Forbush effect which consists on the anti-correlation between the intensity of solar activity and the intensity of secondary cosmic radiation detected at ground level at the Earth. We have used a cylindrical water Cherenkov detector to measure the rate of arrival of secondary cosmic rays in Morelia Mich., Mexico, at 1950 m.a.s.l. We describe the analysis required to unfold the effect of atmospheric pressure and the search for Forbush decreases in our data, the latter correspond to more than one year of continuous data collection.

  6. Optical properties of water for the Yangbajing water cherenkov detector

    NASA Astrophysics Data System (ADS)

    Gao, Shang-qi; Sun, Zhi-bin; Jiang, Yuan-da; Wang, Chao; Du, Ke-ming

    2011-08-01

    Cherenkov radiation is used to study the production of particles during collisions, cosmic rays detections and distinguishing between different types of neutrinos and electrons. The optical properties of water are very important to the research of Cherenkov Effect. Lambert-beer law is a method to study the attenuation of light through medium. In this paper, optical properties of water are investigated by use of a water attenuation performance test system. The system is composed of the light-emitting diode (LED) light source and the photon receiver models. The LED light source model provides a pulse light signal which frequency is 1 kHz and width is 100ns. In photon receiver model, a high sensitivity photomultiplier tube (PMT) is used to detect the photons across the water. Because the output voltage amplitude of PMT is weak which is from 80mv to 120mV, a low noise pre-amplifier is used to improve the detector precise. An effective detector maximum time window of PMT is 100ns for a long lifetime, so a peak holder circuit is used to hold the maximum peak amplitude of PMT for the induced photons signal before the digitalization. In order to reduce the noise of peak holder, a multi-pulse integration is used before the sampling of analog to digital converter. At last, the detector of photons from the light source to the PMT across the water is synchronized to the pulse width of the LED. In order to calculate the attenuation coefficient and attenuation length of water precisely, the attenuation properties of air-to-water boundary is considered in the calculation.

  7. Progress and commissioning of the SLD Cherenkov Ring Imaging Detector

    SciTech Connect

    Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H. . Dept. of Physics); Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S.; Dunwoodie, W.; Hallewell, G.: Kawahara, H.; Kwon, Y.; Leith, D.W.G.S.; Muller, D.; Nagamine, T.; Pavel, T.J.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va'vra, J.; Williams, S.H. (Stanford Linear Accelerator

    1991-11-01

    We report the recent progress of the SLD Cherenkov Ring Imaging Detector. All of the individual components of the device (TPC's, mirrors, liquid radiator trays) have been completed and installed. Almost half of the electronics packages are installed and operational, and the data acquisition system has been commissioned. The liquid C{sub 6}F{sub 14} recirculation system is functioning. The drift gas supply systems are operating well with TMAE, and the gaseous Freon C{sub 5}F{sub 12} recirculator is being brought on-line. Our monitor and control systems are fully functional. The commissioning of all 40 TPCs at full operating voltage has gone very smoothly. The system shows a remarkable immunity to the SLC backgrounds, and yields very clean events, while operating with a single electron sensitivity.

  8. SNM Detection with an Optimized Water Cherenkov Neutron Detector

    DOE PAGESBeta

    Dazeley, S.; Sweany, M.; Bernstein, A.

    2012-07-23

    Special Nuclear Material (SNM) can either spontaneously fission or be induced to do so: either case results in neutron emission. For this reason, neutron detection performs a crucial role in the functionality of Radiation Portal Monitoring (RPM) devices. Since neutrons are highly penetrating and difficult to shield, they could potentially be detected escaping even a well-shielded cargo container. If the shielding were sophisticated, detecting escaping neutrons would require a highly efficient detector with close to full solid angle coverage. In 2008, we reported the successful detection of neutrons with a 250 liter (l) gadolinium doped water Cherenkov prototype—a technology thatmore » could potentially be employed cost effectively with full solid angle coverage. More recently we have built and tested both 1-kl and 3.5-kl versions, demonstrating that very large, cost effective, non-flammable and environmentally benign neutron detectors can be operated efficiently without being overwhelmed by background. In our paper, we present a new design for a modular system of water-based neutron detectors that could be deployed as a real RPM. The modules contain a number of optimizations that have not previously been combined within a single system. We present simulations of the new system, based on the performance of our previous detectors. These simulations indicate that an optimized system such as is presented here could achieve SNM sensitivity competitive with a large 3He-based system. Moreover, the realization of large, cost effective neutron detectors could, for the first time, enable the detection of multiple neutrons per fission from within a large object such as a cargo container. Such a signal would provide a robust indication of the presence of fissioning material, reducing the frequency of false alarms while increasing sensitivity.« less

  9. SNM Detection with an Optimized Water Cherenkov Neutron Detector

    SciTech Connect

    Dazeley, S.; Sweany, M.; Bernstein, A.

    2012-07-23

    Special Nuclear Material (SNM) can either spontaneously fission or be induced to do so: either case results in neutron emission. For this reason, neutron detection performs a crucial role in the functionality of Radiation Portal Monitoring (RPM) devices. Since neutrons are highly penetrating and difficult to shield, they could potentially be detected escaping even a well-shielded cargo container. If the shielding were sophisticated, detecting escaping neutrons would require a highly efficient detector with close to full solid angle coverage. In 2008, we reported the successful detection of neutrons with a 250 liter (l) gadolinium doped water Cherenkov prototype—a technology that could potentially be employed cost effectively with full solid angle coverage. More recently we have built and tested both 1-kl and 3.5-kl versions, demonstrating that very large, cost effective, non-flammable and environmentally benign neutron detectors can be operated efficiently without being overwhelmed by background. In our paper, we present a new design for a modular system of water-based neutron detectors that could be deployed as a real RPM. The modules contain a number of optimizations that have not previously been combined within a single system. We present simulations of the new system, based on the performance of our previous detectors. These simulations indicate that an optimized system such as is presented here could achieve SNM sensitivity competitive with a large 3He-based system. Moreover, the realization of large, cost effective neutron detectors could, for the first time, enable the detection of multiple neutrons per fission from within a large object such as a cargo container. Such a signal would provide a robust indication of the presence of fissioning material, reducing the frequency of false alarms while increasing sensitivity.

  10. Selective Filtration of Gadolinium Trichloride for Use in Neutron Detection in Large Water Cherenkov Detectors

    SciTech Connect

    Vagins, Mark R.

    2013-04-10

    Water Cherenkov detectors have been used for many years as inexpensive, effective detectors for neutrino interactions and nucleon decay searches. While many important measurements have been made with these detectors a major drawback has been their inability to detect the absorption of thermal neutrons. We believe an inexpensive, effective technique could be developed to overcome this situation via the addition to water of a solute with a large neutron cross section and energetic gamma daughters which would make neutrons detectable. Gadolinium seems an excellent candidate especially since in recent years it has become very inexpensive, now less than $8 per kilogram in the form of commercially-available gadolinium trichloride, GdCl{sub 3}. This non-toxic, non-reactive substance is highly soluble in water. Neutron capture on gadolinium yields a gamma cascade which would be easily seen in detectors like Super-Kamiokande. We have been investigating the use of GdCl{sub 3} as a possible upgrade for the Super-Kamiokande detector with a view toward improving its performance as a detector for atmospheric neutrinos, supernova neutrinos, wrong-sign solar neutrinos, reactor neutrinos, proton decay, and also as a target for the coming T2K long-baseline neutrino experiment. This focused study of selective water filtration and GdCl{sub 3} extraction techniques, conducted at UC Irvine, followed up on highly promising benchtop-scale and kiloton-scale work previously carried out with the assistance of 2003 and 2005 Advanced Detector Research Program grants.

  11. Comparative Analysis of Cherenkov Light Detectors in an Oil Drum

    NASA Astrophysics Data System (ADS)

    Niduaza, Rexavalmar; Wedel, Zachary; Castro, Juan; Zavala, Favian; Fan, Sewan; Fatuzzo, Laura

    2014-03-01

    The multi-pixel photon counters (MPPC) has been used in a number of research development in astro-particle physics and particle physics. In an effort to further implement the MPPC detector, we constructed a modular experimental setup using a 16-inch tall acrylic cylinder filled with distilled water as the light producing medium to determine its feasibility as a possible detector for weak Cherenkov light. We have since progressed towards utilizing an oil drum (approximately 30 gallons) as our light-tight container replacing our prototype. In this talk, we would discuss the results regarding our investigation utilizing 1-inch and 3-inch photo-multiplier tubes (PMTs) in an oil drum as we did for our prototype. We would also present our experimental findings comparing our prototype and our oil drum setup using PMTs in coincidence with the MPPC coupled with wavelength-shifting fibers that are submerged in distilled water inside the oil drum vessel. Department of Education grant nymber P031S90007.

  12. Cherenkov detectors for spatial imaging applications using discrete-energy photons

    NASA Astrophysics Data System (ADS)

    Rose, Paul B.; Erickson, Anna S.

    2016-08-01

    Cherenkov detectors can offer a significant advantage in spatial imaging applications when excellent timing response, low noise and cross talk, large area coverage, and the ability to operate in magnetic fields are required. We show that an array of Cherenkov detectors with crude energy resolution coupled with monochromatic photons resulting from a low-energy nuclear reaction can be used to produce a sharp image of material while providing large and inexpensive detector coverage. The analysis of the detector response to relative transmission of photons with various energies allows for reconstruction of material's effective atomic number further aiding in high-Z material identification.

  13. Underground Prototype Water Cherenkov Muon Detector with the Tibet Air Shower Array

    SciTech Connect

    Amenomori, M.; Nanjo, H.; Bi, X. J.; Ding, L. K.; Feng, Zhaoyang; He, H. H.; Hu, H. B.; Lu, H.; Lu, S. L.; Ren, J. R.; Tan, Y. H.; Wang, B.; Wang, H.; Wang, Y.; Wu, H. R.; Zhang, H. M.; Zhang, J. L.; Zhang, Y.; Chen, D.; Kawata, K.

    2008-12-24

    We are planning to build a 10,000 m{sup 2} water-Cherenkov-type muon detector (MD) array under the Tibet air shower (AS) array. The Tibet AS+MD array will have the sensitivity to detect gamma rays in the 100 TeV region by an order of the magnitude better than any other previous existing detectors in the world. In the late fall of 2007, a prototype water Cherenkov muon detector of approximately 100 m{sup 2} was constructed under the existing Tibet AS array. The preliminary data analysis is in good agreement with our MC simulation. We are now ready for further expanding the underground water Cherenkov muon detector.

  14. Use of Cherenkov-type detectors for measurements of runaway electrons in the ISTTOK tokamak

    SciTech Connect

    Plyusnin, V. V.; Fernandes, H.; Silva, C.; Duarte, P.

    2008-10-15

    Gas, fluid, or solid Cherenkov-type detectors have been widely used in high-energy physics for determination of parameters of charged particles, which are moving with relativistic velocities. This paper presents experimental results on the detection of runaway electrons using Cherenkov-type detectors in the ISTTOK tokamak discharges. Such detectors have been specially designed for measurements of energetic electrons in tokamak plasma. The technique based on the use of the Cherenkov-type detectors has enabled the detection of energetic electrons (energies higher than 80 keV) and determination of their spatial and temporal parameters in the ISTTOK discharges. Obtained experimental data were found in adequate agreement to the results of numerical modeling of the runaway electron generation in ISTTOK.

  15. Picosecond Cherenkov detectors for high-energy heavy ion experiments at LHEP/JINR

    NASA Astrophysics Data System (ADS)

    Yurevich, V. I.; Batenkov, O. I.

    2016-07-01

    The modular Cherenkov detectors based on MCP-PMTs are developed for study Au+Au collisions in MPD and BM@N experiments with beams of Nuclotron and future collider NICA in Dubna. The aim of the detector is fast and effective triggering nucleus-nucleus collisions and generation of start signal for TOF detectors. The detector performance is studied with MC simulation and test measurements with a beam of Nuclotron.

  16. Electrostatic design of the barrel CRID (Cherenkov Ring Imaging Detector) and associated measurements

    SciTech Connect

    Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H. . Dept. of Physics); Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.W.G.S.; Muller, D.; Nagamine, T.; Pavel, T.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va'Vra, J. Williams, H. (Stanford Linear Accelerator Center, Menlo Park, CA (US

    1990-04-01

    We report on the electrostatic design and related measurements of the barrel Cherenkov Ring Imaging Detector for the Stanford Large Detector experiment at the Stanford Linear Accelerator Center Linear Collider. We include test results of photon feedback in TMAE-laden gas, distortion measurements in the drift boxes and corona measurements. 13 refs., 21 figs.

  17. The Optical Characterization of Aerogel Tiles for Cherenkov Detectors at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Dittmann, Alexander

    2014-09-01

    The purpose of this project is to determine the scattering and absorption lengths of aerogel tiles of refractive indices ranging from 1.03 to 1.01 produced by Matsushita Electric Works and Japanese Fine Ceramics Center which are used in the Cherenkov detectors at Jefferson Lab. Cerenkov detectors use Cherenkov radiation to detect and identify particles traveling though them. Since light traveling through aerogel is integral to their use as Cherenkov counters, knowledge of aerogel's optical properties is essential. The optical properties measured were the likelihood of a photon being absorbed or scattered as it passed through aerogel. Both properties were tested by shining a collimated beam of light 470 nm LED light through different thicknesses of aerogel: up to 20 tiles each about 1 cm thick. The change in intensity was measured with a 5-inch photomultiplier tube. Scattering has a great effect over large distances and absorption has a very small effect over shorter distances. Scattering was measured first, at aerogel thicknesses of 1-5 cm, absorption measured at distances of 10-20 cm, taking into account the previously calculated scattering. This presentation will consist of the results on the scattering and absorption length of aerogel for use in Jlab's Cherenkov detectors. The purpose of this project is to determine the scattering and absorption lengths of aerogel tiles of refractive indices ranging from 1.03 to 1.01 produced by Matsushita Electric Works and Japanese Fine Ceramics Center which are used in the Cherenkov detectors at Jefferson Lab. Cerenkov detectors use Cherenkov radiation to detect and identify particles traveling though them. Since light traveling through aerogel is integral to their use as Cherenkov counters, knowledge of aerogel's optical properties is essential. The optical properties measured were the likelihood of a photon being absorbed or scattered as it passed through aerogel. Both properties were tested by shining a collimated beam of

  18. Study of wavelength-shifting chemicals for use in large-scale water Cherenkov detectors

    SciTech Connect

    Sweany, M; Bernstein, A; Dazeley, S; Dunmore, J; Felde, J; Svoboda, R; Tripathi, S M

    2011-09-21

    Cherenkov detectors employ various methods to maximize light collection at the photomultiplier tubes (PMTs). These generally involve the use of highly reflective materials lining the interior of the detector, reflective materials around the PMTs, or wavelength-shifting sheets around the PMTs. Recently, the use of water-soluble wavelength-shifters has been explored to increase the measurable light yield of Cherenkov radiation in water. These wave-shifting chemicals are capable of absorbing light in the ultravoilet and re-emitting the light in a range detectable by PMTs. Using a 250 L water Cherenkov detector, we have characterized the increase in light yield from three compounds in water: 4-Methylumbelliferone, Carbostyril-124, and Amino-G Salt. We report the gain in PMT response at a concentration of 1 ppm as: 1.88 {+-} 0.02 for 4-Methylumbelliferone, stable to within 0.5% over 50 days, 1.37 {+-} 0.03 for Carbostyril-124, and 1.20 {+-} 0.02 for Amino-G Salt. The response of 4-Methylumbelliferone was modeled, resulting in a simulated gain within 9% of the experimental gain at 1 ppm concentration. Finally, we report an increase in neutron detection performance of a large-scale (3.5 kL) gadolinium-doped water Cherenkov detector at a 4-Methylumbelliferone concentration of 1 ppm.

  19. Study of timing performance of silicon photomultiplier and application for a Cherenkov detector

    NASA Astrophysics Data System (ADS)

    Ahmed, G. S. M.; Bühler, P.; Marton, J.; Suzuki, K.

    2011-02-01

    Silicon photomultipliers are very versatile photo-detectors due to their high photon detection efficiency, fast response, single photon counting capability, high amplification, and their insensitivity to magnetic fields. At our institute we are studying the performance of these photo-detectors at various operating conditions. On the basis of the experience in the laboratory we built a prototype of a timing Cherenkov detector consisting of a quartz radiator with two 3×3 mm 2 MPPCs S10362-33-100C from Hamamatsu Photonics as photo-detectors. The MPPC sensors were operated with Peltier cooling to minimize thermal noise and to avoid gain drifts. The test measurements at the DA Φ NE Beam-Test Facility (BTF) at the Laboratori Nazionali di Frascati (LNF) with pulsed 490 MeV electrons and the results on timing performance with Cherenkov photons are presented.

  20. Monitor and control systems for the SLD Cherenkov Ring Imaging Detector

    SciTech Connect

    Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dunwoodie, W.; Fernandez, F.; Hallewell, G.; Kawahara, H.; Korff, P.; Kwon, Y.; Leith, D.; Muller, D.; Nagamine, T.; Pavel, T.; Rabinowitz, L.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va'Vra, J.; Williams, S.; Whitaker, J.; Wilson, R.J.; Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; McHugh, S.; Mathys, L.; Morriso

    1989-10-01

    To help ensure the stable long-term operation of a Cherenkov Ring Detector at high efficiency, a comprehensive monitor and control system is being developed. This system will continuously monitor and maintain the correct operating temperatures, and will provide an on-line monitor and maintain the correct operating temperatures, and will provide an on-line monitor of the pressures, flows, mixing, and purity of the various fluids. In addition the velocities and trajectories of Cherenkov photoelectrons drifting within the imaging chambers will be measured using a pulsed uv lamp and a fiberoptic light injection system. 9 refs., 6 figs.

  1. Gamma Ray Measurements at OMEGA with the Newest Gas Cherenkov Detector “GCD-3”

    NASA Astrophysics Data System (ADS)

    McEvoy, A. M.; Herrmann, H. W.; Kim, Y.; Zylstra, A. B.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Sedillo, T. J.; Archuleta, T. N.; Aragonez, R. J.; Malone, R. M.; Horsfield, C. J.; Rubery, M.; Gales, S.; Leatherland, A.; Stoeffl, W.; Gatu Johnson, M.; Shmayda, W. T.; Batha, S. H.

    2016-05-01

    Initial results from the newest Gas Cherenkov Detector (GCD-3) are reported demonstrating improved performance over previous GCD iterations. Increased shielding and lengthening of the Cherenkov photon optical path have resulted in a diminished precursor signal with increased temporal separation between the precursor and the primary DT Cherenkov signal. Design changes resulted in a measured GCD-3 sensitivity comparable to GCD-1 at identical 100 psia CO2 operation. All metal gasket seals and pressure vessel certification to 400 psia operation allow for a GCD-3 lower Cherenkov threshold of 1.8 MeV using the fluorinated gas C2F6 as compared to the 6.3 MeV lower limit of GCD-1 and GCD-2. Calibration data will be used to benchmark GEANT4 and ACCEPT detector models. The GCD-3 acts as a prototype for the Super GCD being fielded at the National Ignition Facility (NIF) as part of the National Diagnostics Plan and will be installed at NIF in early 2016.

  2. Gamma ray measurements at OMEGA with the newest gas Cherenkov Detector “GCD-3”

    DOE PAGESBeta

    McEvoy, A. M.; Herrmann, H. W.; Kim, Y.; Zylstra, A. B.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Sedillo, T. J.; Archuleta, T. N.; et al

    2016-05-01

    Initial results from the newest Gas Cherenkov Detector (GCD-3) are reported demonstrating improved performance over previous GCD iterations. Increased shielding and lengthening of the Cherenkov photon optical path have resulted in a diminished precursor signal with increased temporal separation between the precursor and the primary DT Cherenkov signal. Design changes resulted in a measured GCD-3 sensitivity comparable to GCD-1 at identical 100 psia CO2 operation. All metal gasket seals and pressure vessel certification to 400 psia operation allow for a GCD-3 lower Cherenkov threshold of 1.8 MeV using the fluorinated gas C2F6 as compared to the 6.3 MeV lower limitmore » of GCD-1 and GCD-2. Calibration data will be used to benchmark GEANT4 and ACCEPT detector models. Lastly, the GCD-3 acts as a prototype for the Super GCD being fielded at the National Ignition Facility (NIF) as part of the National Diagnostics Plan and will be installed at NIF in early 2016.« less

  3. Design, transport, and installation of autonomous Cherenkov detectors at high altitude

    NASA Astrophysics Data System (ADS)

    Rubén Calderón Cueva, Mario; Alejandro Vasquez, Nicolas; Martínez, Oscar; Carrera, Edgar; Cazar, Dennis; Audelo, Mario; Mantilla, Cristina; Quishpe, Raquel

    2015-08-01

    Ecuador, as a member of the Latin American Giant Observatory (LAGO), wishes to expand the understanding of astroparticle physics and space weather by the installation of Water Cherenkov detectors at high altitude. The challenge for such devices lies on their transport to the remote areas of operation, the autonomy of their electrical power supply, the robustness of their data transmission system, their remote operation stability, and the reliability of the water integrity for long periods of time. LAGO Ecuador features several studies of gamma ray bursts and high energy astrophysical sources, as well as of space weather. Based on these studies, we develop a feasibility study for the design, installation, operation and maintenance of the aforementioned devices in Papallacta, Chimborazo and Cruz Loma in the Ecuadorean highlands. As the atmospheric absorption, and so the area of detection to be instrumented, is significantly reduced with the altitude, the easy access to locations higher than 4000 m a.s.l. is one of the main advantages of the Ecuadorean Andes for the installation of these facilities.

  4. Special Nuclear Material Detection with a Water Cherenkov based Detector

    SciTech Connect

    Sweany, M; Bernstein, A; Bowden, N; Dazeley, S; Svoboda, R

    2008-11-10

    Fission events from Special Nuclear Material (SNM), such as highly enriched uranium or plutonium, produce a number of neutrons and high energy gamma-rays. Assuming the neutron multiplicity is approximately Poissonian with an average of 2 to 3, the observation of time correlations between these particles from a cargo container would constitute a robust signature of the presence of SNM inside. However, in order to be sensitive to the multiplicity, one would require a high total efficiency. There are two approaches to maximize the total efficiency; maximizing the detector efficiency or maximizing the detector solid angle coverage. The advanced detector group at LLNL is investigating one way to maximize the detector size. We are designing and building a water Cerenkov based gamma and neutron detector for the purpose of developing an efficient and cost effective way to deploy a large solid angle car wash style detector. We report on our progress in constructing a larger detector and also present preliminary results from our prototype detector that indicates detection of neutrons.

  5. The CLEO-III ring imaging Cherenkov detector

    NASA Astrophysics Data System (ADS)

    Mountain, R. J.; Artuso, M.; Ayad, R.; Azfar, F.; Efimov, A.; Kopp, S.; Majumder, G.; Schuh, S.; Skwarnicki, T.; Stone, S.; Viehhauser, G.; Wang, J. C.; Anderson, S.; Smith, A.; Kubota, Y.; Lipeles, E.; Coan, T.; Staeck, J.; Fadeyev, V.; Volobouev, I.; Ye, J.

    1999-08-01

    The CLEO-III detector upgrade for charged particle identification is discussed. The RICH design uses solid LiF crystal radiators coupled with multi-wire chamber photon detectors, using TEA as the photosensor, and low-noise Viking readout electronics. Results from our beam test at Fermilab are presented.

  6. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detector

    SciTech Connect

    Hellfeld, D.; Dazeley, S.; Bernstein, A.; Marianno, C.

    2015-11-25

    The potential of elastic antineutrino-electron scattering (ν¯e + e → ν¯e + e) in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13 km standoff from a 3.758 GWt light water nuclear reactor. Background was estimated via independent simulations and by appropriately scaling published measurements from similar detectors. Many potential backgrounds were considered, including solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclide and water-borne radon decays, and gamma rays from the photomultiplier tubes, detector walls, and surrounding rock. The detector response was modeled using a GEANT4-based simulation package. The results indicate that with the use of low radioactivity PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. The directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. Lastly, the results provide a list of theoretical conditions that, if satisfied in practice, would enable nuclear reactor antineutrino directionality in a Gd-doped water Cherenkov detector approximately 10 km from a large power reactor.

  7. Instrumentation and performance of the water Cherenkov detector array at Sierra La Negra site

    NASA Astrophysics Data System (ADS)

    Salazar, H.; Alvarez, C.; Martinez, O.; Villasenor, L.; Perez, E.; Grajales, J.; Murrieta, T.

    We present results from the operation of the high mountain array of 4 water Cherenkov detectors located at 4550 m. a.s.l. located at Sierra Negra mountain (N 18 59.1, W 97 18.76 ) near of Puebla city in Mexico. The detectors consist of 4 light-tight cylindrical containers of 4 m2 cross section separated 25m. The vertices of the array form a triangle with one detector in the middle. The detector containers are filled with 5000 l of purified water and have a 5'' photomultiplier (EMI model 9030 A) facing down along the cylindrical axes. The acquisition electronics consists of scalers counting the number of particles every 5 ms, and an osciloscope used to fully record the traces of the four signals coming from the water Cherenkov detectors. The trigger signals correspond to photon candidate coming from a selected direction with an accuracy lower than one degree. Data and preliminary analysis are described corresponding to the last six months when operation of this detector array has been stable.

  8. Large acceptance forward Cherenkov detector for the BRAHMS experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Budick, B.; Beavis, D.; Chasman, C.

    2010-09-01

    A multi-element detector based on Cherenkov radiation in plastic and on photomultiplier tubes has been constructed that is particularly useful in collider experiments. The detector covers the pseudorapidity interval 3.23< η<5.25 with large acceptance for the products of proton-proton and heavy ion collisions. The detector's primary purposes are determining the vertex of the interaction, providing a minimum bias trigger, finding the start time for time of flight (and other timing applications), and monitoring the luminosity. Monte Carlo simulations describe the pulse height response of the detector well, as does an analytic expression that has been developed. The detector performed well in the RHIC experiment BRAHMS.

  9. Evaluation of Multi-Anode Photomultipliers for the CLAS12 Ring-Imaging Cherenkov Detector

    NASA Astrophysics Data System (ADS)

    Samuel, Jenna

    2015-04-01

    Thomas Jefferson National Accelerator Facility has recently upgraded its Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS12) to provide a comprehensive study of the complex internal structure and dynamics of the nucleon. The upgrade includes new detectors such as the Ring Imaging Cherenkov detector (RICH). The RICH will use multi-anode photomultipliers (MAPMTs) for the detection of Cherenkov photons. Our study compared two models of Hamamatsu MAPMTs (H8500 and H12700) under consideration for the CLAS12 RICH in terms of their single photoelectron (SPE) peak, dark current, and crosstalk. The MAPMTs were tested inside a light-tight box, using a low intensity laser to simulate single photoelectron events similar to Cherenkov radiation. The H12700's SPE peaks were on average 78% the width of the H8500's peaks. For both models, the probability of dark current was on the order of 10-4. The probability of crosstalk for H8500s was 1.6 to 2.7 times that for H12700s. The H12700s were deemed better because they had negligible crosstalk and dark current while providing a narrower peak for single photoelectron events. Thomas Jefferson National Accelerator Facility, Science Undergraduate Laboratory Internship.

  10. Design and fabrication of a window for the gas Cherenkov detector 3

    NASA Astrophysics Data System (ADS)

    Fatherley, V. E.; Bingham, D. A.; Cartelli, M. D.; DiDomizio, R. A.; Griego, J. R.; Herrmann, H. W.; Lopez, F. E.; Oertel, J. A.; Pollack, M. J.

    2016-11-01

    The gas Cherenkov detector 3 was designed at Los Alamos National Laboratory for use in inertial confinement fusion experiments at both the Omega Laser Facility and the National Ignition Facility. This instrument uses a low-Z gamma-to-electron convertor plate and high pressure gas to convert MeV gammas into UV/visible Cherenkov photons for fast optical detection. This is a follow-on diagnostic from previous versions, with two notable differences: the pressure of the gas is four times higher, and it allows the use of fluorinated gas, requiring metal seals. These changes force significant changes in the window component, having a unique set of requirements and footprint limitations. The selected solution for this component, a sapphire window brazed into a stainless steel flange housing, is described.

  11. Application of imaging to the atmospheric Cherenkov technique

    NASA Technical Reports Server (NTRS)

    Cawley, M. F.; Fegan, D. J.; Gibbs, K.; Gorham, P. W.; Hillas, A. M.; Lamb, R. C.; Liebing, D. F.; Mackeown, P. K.; Porter, N. A.; Stenger, V. J.

    1985-01-01

    Turver and Weekes proposed using a system of phototubes in the focal plane of a large reflector to give an air Cherenkov camera for gamma ray astronomy. Preliminary results with a 19 element camera have been reported previously. In 1983 the camera was increased to 37 pixels; it has now been routinely operated for two years. A brief physical description of the camera, its mode of operation, and the data reduction procedures are presented. The Monte Carlo simultations on which these are based on also reviewed.

  12. A G-APD based Camera for Imaging Atmospheric Cherenkov Telescopes

    NASA Astrophysics Data System (ADS)

    Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, S.; Commichau, V.; Dorner, D.; Gendotti, A.; Grimm, O.; von Gunten, H.; Hildebrand, D.; Horisberger, U.; Köhne, J.-H.; Krähenbühl, T.; Kranich, D.; Lorenz, E.; Lustermann, W.; Mannheim, K.; Neise, D.; Pauss, F.; Renker, D.; Rhode, W.; Rissi, M.; Ribordy, M.; Röser, U.; Stark, L. S.; Stucki, J.-P.; Tibolla, O.; Viertel, G.; Vogler, P.; Weitzel, Q.

    2011-02-01

    Imaging Atmospheric Cherenkov Telescopes (IACT) for Gamma-ray astronomy are presently using photomultiplier tubes as photo sensors. Geiger-mode avalanche photodiodes (G-APD) promise an improvement in sensitivity and, important for this application, ease of construction, operation and ruggedness. G-APDs have proven many of their features in the laboratory, but a qualified assessment of their performance in an IACT camera is best undertaken with a prototype. This paper describes the design and construction of a full-scale camera based on G-APDs realized within the FACT project (First G-APD Cherenkov Telescope).

  13. Performance of the Two Aerogel Cherenkov Detectors of the JLab Hall A Hadron Spectrometer

    SciTech Connect

    Marrone, Stefano; Wojtsekhowski, Bogdan; Acha Quimper, Armando; Cisbani, Evaristo; Coman, Marius; Cusanno, Francesco; De Jager, Cornelis; De Leo, Raffaele; Gao, Haiyan; Garibaldi, Franco; Higinbotham, Douglas; Iodice, Mauro; LeRose, John; Macchia, D.; Markowitz, Pete; Nappi, E.; Palmisano, F.; Urciuoli, Guido; van der Werf, I.; XIANG, Hong; Xiang, Hong; XIANG, Hong; Xiang, Hong; Zhu, Lingyan

    2009-01-01

    We report on the design and commissioning of two silica aerogel Cherenkov detectors with different refractive indices. In particular, extraordinary performance in terms of the number of detected photoelectrons was achieved through an appropriate choice of PMT type and reflector, along with some design considerations. After four years of operation, the number of detected photoelectrons was found to be noticeably reduced in both detectors as a result of contamination, yellowing, of the aerogel material. Along with the details of the set-up, we illustrate the characteristics of the detectors during different time periods and the probable causes of the contamination. In particular we show that the replacement of the contaminated aerogel and parts of the reflecting material has almost restored the initial performance of the detectors.

  14. 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.

  15. Design and development of a Gadolinium-doped water Cherenkov detector

    NASA Astrophysics Data System (ADS)

    Poudyal, Nabin

    This thesis describes a research and development project for neutron capture and detection in Gadolinium doped water. The Sanford Underground Research Facility (SURF) is exploring rare event physics, such as neutrinoless double beta decay (MAJORANA Project) and dark-matter detection (LUX experiment). The success of these experiments requires a careful study and understanding of background radiation, including flux and energy spectrum. The background radiation from surface contamination, radioactive decays of U-238, Th-232, Rn-222 in the surrounding rocks and muon induced neutrons have a large impact on the success of rare-event physics. The main objective of this R&D project is to measure the neutron flux contributing to ongoing experiments at SURF and suppress it by identification and capture method. For this purpose, we first modeled and designed a detector with Geant4 software. The approximate dimension of the detector is determined. The neutron capture percentage of the detector is estimated using Monte Carlo. The energy response of the detector is simulated. Next, we constructed the experimental detector, an acrylic rectangular tank (60cm x 30cm x 30cm), filled with Gadolinium-doped deionized water. The tank is coated with high efficient reflector and then taped with black electrical tape to make it opaque. The voltage dividers attached to PMTs are covered with mu-metal. Two 5-inch Hamamatsu Photomultiplier tubes were attached on both sides facing the tank to collect the Cherenkov light produced in the water. The detector utilizes the principle of Cherenkov light emission by a charged particle moving through a water at a speed higher than the speed of light in the water, hence it has an inherent energy threshold of Cherenkov photon production. This property reduces the lower energy backgrounds. Event data are obtained using the Data Acquisition hardware, Flash Analog to digital converter, along with Multi Instance Data Acquisition software. Post

  16. Aerogel Cherenkov detector for characterizing the intense flash x-ray source, Cygnus, spectrum

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Herrmann, H. W.; McEvoy, A. M.; Young, C. S.; Hamilton, C.; Schwellenbach, D. D.; Malone, R. M.; Kaufman, M. I.; Smith, A. S.

    2016-11-01

    An aerogel Cherenkov detector is proposed to measure the X-ray energy spectrum from the Cygnus—intense flash X-ray source operated at the Nevada National Security Site. An array of aerogels set at a variety of thresholds between 1 and 3 MeV will be adequate to map out the bremsstrahlung X-ray production of the Cygnus, where the maximum energy of the spectrum is normally around 2.5 MeV. In addition to the Cherenkov radiation from aerogels, one possible competing light-production mechanism is optical transition radiation (OTR), which may be significant in aerogels due to the large number of transitions from SiO2 clusters to vacuum voids. To examine whether OTR is a problem, four aerogel samples were tested using a mono-energetic electron beam (varied in the range of 1-3 MeV) at NSTec Los Alamos Operations. It was demonstrated that aerogels can be used as a Cherenkov medium, where the rate of the light production is about two orders magnitude higher when the electron beam energy is above threshold.

  17. A Water Cherenkov Detector prototype for the HAWC Gamma-Ray Observatory

    NASA Astrophysics Data System (ADS)

    Longo, Megan; Mostafa, Miguel; Salesa Greus, Francisco; Warner, David

    2011-10-01

    A full-size Water Cherenkov Detector (WCD) prototype for the High Altitude Water Cherenkov (HAWC) gamma-ray Observatory was deployed, and is currently being operated at Colorado State University (CSU). The HAWC Observatory will consist of 300 WCDs at the very high altitude (4100m) site in Sierra Negra, Mexico. Each WCD will have 4 baffled upward-facing Photomultiplier Tubes (PMTs) anchored to the bottom of a self made multilayer hermetic plastic bag containing 200,000 liters of purified water, inside a 5m deep by 7.3m diameter steel container. The full size WCD at CSU is the only full size prototype outside of the HAWC site. It is equipped with seven HAWC PMTs and has scintillators both under and above the volume of water. It has been in operation since March 1, 2011. This prototype also has the same laser calibration system that the detectors deployed at the HAWC site will have. The CSU WCD serves as a testbed for the different subsystems before deployment at high altitude, and for optimizing the location of the PMTs, the design of the light collectors, deployment procedures, etc. Simulations of the light inside the detectors and the expected signals in the PMTs can also be benchmarked with this prototype.

  18. The fluid systems for the SLD Cherenkov ring imaging detector. [01

    SciTech Connect

    Abe, K.; Hasegawa, K.; Hasegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H. . Dept. of Physics); Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.W.G.S.; McCulloch, M.; McShurley, D.; Mueller, G.; Muller, D.; Nagamine, T.; Pavel, T.J.; Peterson, H.; Ratcliff, B.; Reif, R.; Rensing, P.; Schultz, D.; Shapiro, S.; Shaw,

    1992-10-01

    We describe the design and operation of the fluid delivery, monitor and control systems for the SLD barrel Cherenkov Ring Imaging Detector (CRID). The systems deliver drift gas (C[sub 2]H[sub 6] + TMAE), radiator gas (C[sub 5]F[sub 12] + N[sub 2]) and radiator liquid (C[sub 6]F[sub 14]). Measured critical quantities such as electron lifetime in the drift gas and ultra-violet (UV) transparencies of the radiator fluids, together with the operational experience, are also reported.

  19. Cherenkov Detector For Measurements Of Fast Electrons In CASTOR-Tokamak

    SciTech Connect

    Jakubowski, L.; Sadowski, M. J.; Stanislawski, J.; Malinowski, K.; Zebrowski, J.; Jakubowski, M.; Weinzettl, V.; Stockel, J.; Vacha, M.; Peterka, M.

    2008-04-07

    The paper reports on capabilities of an improved version of the Cherenkov detector designed for measurements of fast electrons. The described technique enables the identification of electron beams, the measurements of their temporal characteristics, as well as the estimation of their spatial properties to be performed. Results obtained in the last experimental campaign with the CASTOR facility show good measuring capabilities of such a detection system. The radial distributions of fast-electron streams at different plasma densities, as well as the electron fluency dependences on discharge currents and toroidal magnetic fields are also presented.

  20. 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.

  1. Tests of innovative photon detectors and integrated electronics for the large-area CLAS12 ring-imaging Cherenkov detector

    SciTech Connect

    Contalbrigo, Marco

    2015-07-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab. Its aim is to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and a densely packed and highly segmented photon detector. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). Extensive tests have been performed on Hamamatsu H8500 and novel flat multi-anode photomultipliers under development and on various types of silicon photomultipliers. A large scale prototype based on 28 H8500 MA-PMTs has been realized and tested with few GeV/c hadron beams at the T9 test-beam facility of CERN. In addition a small prototype was used to study the response of customized SiPM matrices within a temperature interval ranging from 25 down to –25 °C. The preliminary results of the individual photon detector tests and of the prototype performance at the test-beams are here reported.

  2. Module of silicon photomultipliers as a detector of individual Cherenkov photons

    NASA Astrophysics Data System (ADS)

    Pestotnik, Rok; Dolenec, Rok; Korpar, Samo; Križan, Peter; Stanovnik, Aleš

    2011-05-01

    We have studied the possibility of using silicon photomultipliers as single photon detectors in a proximity focusing RICH with aerogel radiator. Such a counter is considered for the upgrade of the Belle detector. The main advantage of silicon over conventional photomultiplier tubes is their operation in high magnetic fields. Their disadvantage is the relatively high dark noise count rate (≈MHz/mm2) which can be overcome by using a narrow time window in the data acquisition. A module, consisting of 64 (8×8) Hamamatsu MPPC S10362-11-100P silicon photomultipliers, has been designed, constructed and tested with Cherenkov photons emitted in an aerogel radiator by 120 GeV/ c pions from the CERN T4-H6 beam. To increase the signal-to-noise ratio, i.e. to increase the effective surface on which light is detected, light concentrators have been employed.

  3. The atmosphere as particle detector

    NASA Astrophysics Data System (ADS)

    Stanev, T.

    1990-03-01

    The possibility of using an inflatable, gas-filled balloon as a TeV gamma-ray detector on the moon is considered. By taking an atmosphere of Xenon gas there, or by extracting it on the moon, a layman's detector design is presented. In spite of its shortcomings, the exercise illustrates several of the novel features offered by particle physics on the moon.

  4. The atmosphere as particle detector

    SciTech Connect

    Stanev, T. )

    1990-03-15

    The possibility of using an inflatable, gas-filled balloon as a TeV {gamma}-ray detector on the Moon is considered. By taking an atmosphere of Xenon gas there, or by extracting it on the Moon, a layman's detector design is presented. In spite of its shortcomings, the exercise illustrates several of the novel features offered by particle physics on the Moon.

  5. The atmosphere as particle detector

    NASA Technical Reports Server (NTRS)

    Stanev, Todor

    1990-01-01

    The possibility of using an inflatable, gas-filled balloon as a TeV gamma-ray detector on the moon is considered. By taking an atmosphere of Xenon gas there, or by extracting it on the moon, a layman's detector design is presented. In spite of its shortcomings, the exercise illustrates several of the novel features offered by particle physics on the moon.

  6. Understanding fast neutrons utilizing a water Cherenkov detector and a gas-filled detector at the soudan underground laboratory

    NASA Astrophysics Data System (ADS)

    Ghimire, Chiranjibi

    Many experiments are currently searching for Weakly Interactive Massive Particles (WIMPs), a well-motivated class of hypothetical dark matter candidates. These direct dark matter detection experiments are located in deep underground to shield from cosmic-ray muons and the fast neutrons they produce. Fast neutrons are particularly dangerous to WIMP detectors because they can penetrate a WIMP-search experiment's neutron shielding. Once inside, these fast neutrons can interact with high-Z material near the WIMP detector, producing slower neutrons capable of mimicking the expected WIMP signal. My research uses two detectors located in Soudan Underground Laboratory to understand fast neutron production by muons in an underground environment: a water-Cherenkov detector sensitive to fast neutrons; and a gas-filled detector sensitive to charged particles like muons. The different kinds of selection criterion and their efficiencies are reported in this thesis. This thesis estimate the number of high energy neutron-like candidates associated with a nearby muon by using data from both detector systems.

  7. Muon data from a water Cherenkov detector prototype at Colorado State University

    NASA Astrophysics Data System (ADS)

    Longo, Megan; Mostafa, Miguel

    2013-04-01

    The High Altitude Water Cherenkov (HAWC) Observatory is a very high energy gamma-ray experiment currently under construction in Sierra Negra in the state of Puebla, Mexico, at an altitude of 4,100 m a.s.l. The HAWC Observatory will consist of 300 water Cherenkov detectors (WCDs), each instrumented with three 8'' photomultiplier tubes (PMTs) and one 10'' high efficiency (HE) PMT. The PMTs are upward facing, anchored to the bottom of a 5 m deep by 7.3 m diameter steel tank, containing a multilayer hermetic plastic bag holding 200,000 L of purified water. The only full size WCD prototype outside of the HAWC site is located at Colorado State University (CSU) in Fort Collins, CO at an altitude of 1,525 m a.s.l. This prototype is instrumented with six 8'' PMTs, one 10'' HE PMT, and the same laser calibration system, electronics, and data acquisition system as the WCDs at the HAWC site. The CSU prototype is additionally equipped with scintillator paddles both under and above the volume of water, temperature probes (in the water, outside, and in the DAQ room), and one covered PMT. Preliminary results for muon rates and their temperature dependance using data collected with the CSU prototype will be presented.

  8. Note: Measurements of fast electrons in the TORE-SUPRA tokamak by means of modified Cherenkov-type diamond detector

    SciTech Connect

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Jakubowski, M. J.; Malinowski, K.; Mirowski, R.; Lotte, Ph.; Goniche, M.; Gunn, J.; Colledani, G.; Pascal, J.-Y.; Basiuk, V.

    2013-01-15

    The Note reports on experimental studies of ripple born fast electrons within the TORE-SUPRA facility, which were performed by means of a modified measuring head equipped with diamond detectors designed especially for recording the electron-induced Cherenkov radiation. There are presented signals produced by fast electrons in the TORE-SUPRA machine, which were recorded during two experimental campaigns performed in 2010. Shapes of these electron-induced signals are considerably different from those observed during the first measurements carried out by the prototype Cherenkov probe in 2008. An explanation of the observed differences is given.

  9. Extended performance gas Cherenkov detector for gamma-ray detection in high-energy density experiments.

    PubMed

    Herrmann, H W; Kim, Y H; Young, C S; Fatherley, V E; Lopez, F E; Oertel, J A; Malone, R M; Rubery, M S; Horsfield, C J; Stoeffl, W; Zylstra, A B; Shmayda, W T; Batha, S H

    2014-11-01

    A new Gas Cherenkov Detector (GCD) with low-energy threshold and high sensitivity, currently known as Super GCD (or GCD-3 at OMEGA), is being developed for use at the OMEGA Laser Facility and the National Ignition Facility (NIF). Super GCD is designed to be pressurized to ≤400 psi (absolute) and uses all metal seals to allow the use of fluorinated gases inside the target chamber. This will allow the gamma energy threshold to be run as low at 1.8 MeV with 400 psi (absolute) of C2F6, opening up a new portion of the gamma ray spectrum. Super GCD operating at 20 cm from TCC will be ∼400 × more efficient at detecting DT fusion gammas at 16.7 MeV than the Gamma Reaction History diagnostic at NIF (GRH-6m) when operated at their minimum thresholds. PMID:25430303

  10. Monte Carlo validation experiments for the gas Cherenkov detectors at the National Ignition Facility and Omega

    SciTech Connect

    Rubery, M. S.; Horsfield, C. J.; Herrmann, H.; Kim, Y.; Mack, J. M.; Young, C.; Evans, S.; Sedillo, T.; McEvoy, A.; Caldwell, S. E.; Grafil, E.; Stoeffl, W.; Milnes, J. S.

    2013-07-15

    The gas Cherenkov detectors at NIF and Omega measure several ICF burn characteristics by detecting multi-MeV nuclear γ emissions from the implosion. Of primary interest are γ bang-time (GBT) and burn width defined as the time between initial laser-plasma interaction and peak in the fusion reaction history and the FWHM of the reaction history respectively. To accurately calculate such parameters the collaboration relies on Monte Carlo codes, such as GEANT4 and ACCEPT, for diagnostic properties that cannot be measured directly. This paper describes a series of experiments performed at the High Intensity γ Source (HIγS) facility at Duke University to validate the geometries and material data used in the Monte Carlo simulations. Results published here show that model-driven parameters such as intensity and temporal response can be used with less than 50% uncertainty for all diagnostics and facilities.

  11. Monte Carlo validation experiments for the gas Cherenkov detectors at the National Ignition Facility and Omega.

    PubMed

    Rubery, M S; Horsfield, C J; Herrmann, H; Kim, Y; Mack, J M; Young, C; Evans, S; Sedillo, T; McEvoy, A; Caldwell, S E; Grafil, E; Stoeffl, W; Milnes, J S

    2013-07-01

    The gas Cherenkov detectors at NIF and Omega measure several ICF burn characteristics by detecting multi-MeV nuclear γ emissions from the implosion. Of primary interest are γ bang-time (GBT) and burn width defined as the time between initial laser-plasma interaction and peak in the fusion reaction history and the FWHM of the reaction history respectively. To accurately calculate such parameters the collaboration relies on Monte Carlo codes, such as GEANT4 and ACCEPT, for diagnostic properties that cannot be measured directly. This paper describes a series of experiments performed at the High Intensity γ Source (HIγS) facility at Duke University to validate the geometries and material data used in the Monte Carlo simulations. Results published here show that model-driven parameters such as intensity and temporal response can be used with less than 50% uncertainty for all diagnostics and facilities. PMID:23902060

  12. Extended performance gas Cherenkov detector for gamma-ray detection in high-energy density experiments

    SciTech Connect

    Herrmann, H. W. Kim, Y. H.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Batha, S. H.; Malone, R. M.; Rubery, M. S.; Horsfield, C. J.; Stoeffl, W.; Zylstra, A. B.; Shmayda, W. T.

    2014-11-15

    A new Gas Cherenkov Detector (GCD) with low-energy threshold and high sensitivity, currently known as Super GCD (or GCD-3 at OMEGA), is being developed for use at the OMEGA Laser Facility and the National Ignition Facility (NIF). Super GCD is designed to be pressurized to ≤400 psi (absolute) and uses all metal seals to allow the use of fluorinated gases inside the target chamber. This will allow the gamma energy threshold to be run as low at 1.8 MeV with 400 psi (absolute) of C{sub 2}F{sub 6}, opening up a new portion of the gamma ray spectrum. Super GCD operating at 20 cm from TCC will be ∼400 × more efficient at detecting DT fusion gammas at 16.7 MeV than the Gamma Reaction History diagnostic at NIF (GRH-6m) when operated at their minimum thresholds.

  13. Extended performance gas Cherenkov detector for gamma-ray detection in high-energy density experiments.

    PubMed

    Herrmann, H W; Kim, Y H; Young, C S; Fatherley, V E; Lopez, F E; Oertel, J A; Malone, R M; Rubery, M S; Horsfield, C J; Stoeffl, W; Zylstra, A B; Shmayda, W T; Batha, S H

    2014-11-01

    A new Gas Cherenkov Detector (GCD) with low-energy threshold and high sensitivity, currently known as Super GCD (or GCD-3 at OMEGA), is being developed for use at the OMEGA Laser Facility and the National Ignition Facility (NIF). Super GCD is designed to be pressurized to ≤400 psi (absolute) and uses all metal seals to allow the use of fluorinated gases inside the target chamber. This will allow the gamma energy threshold to be run as low at 1.8 MeV with 400 psi (absolute) of C2F6, opening up a new portion of the gamma ray spectrum. Super GCD operating at 20 cm from TCC will be ∼400 × more efficient at detecting DT fusion gammas at 16.7 MeV than the Gamma Reaction History diagnostic at NIF (GRH-6m) when operated at their minimum thresholds.

  14. Extended performance gas Cherenkov detector for gamma-ray detection in high-energy density experimentsa)

    NASA Astrophysics Data System (ADS)

    Herrmann, H. W.; Kim, Y. H.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Malone, R. M.; Rubery, M. S.; Horsfield, C. J.; Stoeffl, W.; Zylstra, A. B.; Shmayda, W. T.; Batha, S. H.

    2014-11-01

    A new Gas Cherenkov Detector (GCD) with low-energy threshold and high sensitivity, currently known as Super GCD (or GCD-3 at OMEGA), is being developed for use at the OMEGA Laser Facility and the National Ignition Facility (NIF). Super GCD is designed to be pressurized to ≤400 psi (absolute) and uses all metal seals to allow the use of fluorinated gases inside the target chamber. This will allow the gamma energy threshold to be run as low at 1.8 MeV with 400 psi (absolute) of C2F6, opening up a new portion of the gamma ray spectrum. Super GCD operating at 20 cm from TCC will be ˜400 × more efficient at detecting DT fusion gammas at 16.7 MeV than the Gamma Reaction History diagnostic at NIF (GRH-6m) when operated at their minimum thresholds.

  15. Progress and commissioning of the SLD Cherenkov Ring Imaging Detector. Revision

    SciTech Connect

    Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H.; Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S.; Dunwoodie, W.; Hallewell, G.: Kawahara, H.; Kwon, Y.; Leith, D.W.G.S.; Muller, D.; Nagamine, T.; Pavel, T.J.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va`vra, J.; Williams, S.H.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Witherell, M.; Yellin, S.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Williams, D.A.; d`Oliveira, A.; Johnson, R.A.; Martinez, J.; Meadows, B.; Nussbaum, M.; Santha, A.K.S.; Shoup, A.; Sokoloff, M.; Stockdale, I.; Whitaker, J.S.; Wilson, R.J.

    1991-11-01

    We report the recent progress of the SLD Cherenkov Ring Imaging Detector. All of the individual components of the device (TPC`s, mirrors, liquid radiator trays) have been completed and installed. Almost half of the electronics packages are installed and operational, and the data acquisition system has been commissioned. The liquid C{sub 6}F{sub 14} recirculation system is functioning. The drift gas supply systems are operating well with TMAE, and the gaseous Freon C{sub 5}F{sub 12} recirculator is being brought on-line. Our monitor and control systems are fully functional. The commissioning of all 40 TPCs at full operating voltage has gone very smoothly. The system shows a remarkable immunity to the SLC backgrounds, and yields very clean events, while operating with a single electron sensitivity.

  16. Measurement of DT fusion and neutron-induced gamma-rays using gas Cherenkov Detector

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Herrmann, H. W.; Evans, S.; Sedillo, T.; Langenbrunner, J. R.; Young, C. S.; Mack, J. M.; McEvoy, A.; Horsfield, C. J.; Rubery, M.; Ali, Z.; Stoeffl, W.

    2010-08-01

    A secondary gamma experiment was carried out using a Gas Cherenkov Detector (GCD) at the OMEGA laser facility. The primary experimental objective was to simulate neutron-induced secondary gamma production (n-γ) from a NIF implosion capsule, hohlraum, and thermo-mechanical package. The high-band width of the GCD enabled us to detect time delayed and Doppler broadened n-γ signals from five different puck materials (Si, SiO2, Al, Al2O3, Cu) placed near target chamber center. These measurements were used for MCNP & ITS ACCEPT code validation purposes. By a simple change of the GCD CO2 gas pressure the system can effectively eliminate signals induced by n-γ reactions and thereby allow quality measurements of DT fusion γ-rays that are produced at NIF (National Ignition Facility).

  17. Comparison of the Response of the UV and visible Cherenkov Telescopes to the Atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Badran, Hussein

    With atmospheric Cherenkov telescopes the experiment is totally at the mercy of the environment; particularly the atmospheric conditions. The effect of the atmospheric conditions on the Cherenkov light flashes is closely investigated for UV and visible cameras. The telescope response for light generated at different altitudes does not have the same variation with the wind speed or cloud thickness. For both cameras measurements can be carried out up to wind speed ~17 m/s without much change of the atmospheric transmittance from light generated close to the observing level and up to 12 m/s for higher elevation and higher zenith angles. The suggested limit for cloud thickness for both cameras is around 0.5 km. A cloud thickness of ~0.9 km can be tolerated for zenith angles less than 30°. The suggested limits are particularly important whenever the spectrum is to be determined from the data. No real change of the response function with the air pressure and temperature was found. The seasonal variation has a slight effect on the telescope response.

  18. SiPM detectors for the ASTRI project in the framework of the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Billotta, Sergio; Marano, Davide; Bonanno, Giovanni; Belluso, Massimiliano; Grillo, Alessandro; Garozzo, Salvatore; Romeo, Giuseppe; Timpanaro, Maria Cristina; Maccarone, Maria Concetta C.; Catalano, Osvaldo; La Rosa, Giovanni; Sottile, Giuseppe; Impiombato, Domenico; Gargano, Carmelo; Giarrusso, Salavtore

    2014-07-01

    The Cherenkov Telescope Array (CTA) is a worldwide new generation project aimed at realizing an array of a hundred ground based gamma-ray telescopes. ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is the Italian project whose primary target is the development of an end-to-end prototype, named ASTRI SST-2M, of the CTA small size class of telescopes devoted to investigation of the highest energy region, from 1 to 100 TeV. Next target is the implementation of an ASTRI/CTA mini-array based on seven identical telescopes. Silicon Photo-Multipliers (SiPMs) are the semiconductor photosensor devices designated to constitute the camera detection system at the focal plane of the ASTRI telescopes. SiPM photosensors are suitable for the detection of the Cherenkov flashes, since they are very fast and sensitive to the light in the 300-700nm wavelength spectrum. Their drawbacks compared to the traditional photomultiplier tubes are high dark count rates, after-pulsing and optical cross-talk contributions, and intrinsic gains strongly dependent on temperature. Nonetheless, for a single pixel, the dark count rate is well below the Night Sky Background, the effects of cross-talk and afterpulses are typically lower than 20%, and the gain can be kept stable against temperature variations by means of adequate bias voltage compensation strategies. This work presents and discusses some experimental results from a large set of measurements performed on the SiPM sensors to be used for the ASTRI SST-2M prototype camera and on recently developed detectors demonstrating outstanding performance for the future evolution of the project in the ASTRI/CTA mini-array.

  19. ``Super'' Gas Cherenkov Detector for Gamma Ray Measurements at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Herrmann, Hans W.; Kim, Y. H.; McEvoy, A. M.; Zylstra, A. B.; Lopez, F. E.; Griego, J. R.; Fatherley, V. E.; Oertel, J. A.; Batha, S. H.; Stoeffl, W.; Church, J. A.; Carpenter, A.; Rubery, M. S.; Horsfield, C. J.; Gales, S.; Leatherland, A.; Hilsabeck, T.; Kilkenny, J. D.; Malone, R. M.; Shmayda, W. T.

    2015-11-01

    New requirements to improve reaction history and ablator areal density measurements at the NIF necessitate improvements in sensitivity, temporal and spectral response relative to the existing Gamma Reaction History diagnostic (GRH-6m) located 6 meters from target chamber center (TCC). A new DIM-based ``Super'' Gas Cherenkov Detector (GCD) will ultimately provide ~ 200x more sensitivity to DT fusion gamma rays, reduce the effective temporal resolution from ~ 100 to ~ 10 ps and lower the energy threshold from 2.9 to 1.8 MeV, relative to GRH-6m. The first phase is to insert the existing coaxial GCD-3 detector into a reentrant well on the NIF chamber which will put it within 4 meters of TCC. This diagnostic platform will allow assessment of the x-ray radiation background environment within the well which will be fed into the shielding design for the follow-on ``Super'' GCD. It will also enable use of a pulse-dilation PMT which has the potential to improve the effective measurement bandwidth by ~ 10x relative to current PMT technology. GCD-3 has been thoroughly tested at the OMEGA Laser Facility and characterized at the High Intensity Gamma Ray Source (HIgS).

  20. CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET

    SciTech Connect

    Somlai-Schweiger, I. Ziegler, S. I.

    2015-04-15

    Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm{sup 3} and 10 × 10 × 10 mm{sup 3}. For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO{sub 4}. Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from

  1. Supernova remnants and pulsar wind nebulae with Imaging Atmospheric Cherenkov Telescopes (IACTs)

    NASA Astrophysics Data System (ADS)

    Eger, Peter

    2015-08-01

    The observation of very-high-energy (VHE, E > 100 GeV) gamma rays is an excellent tool to study the most energetic and violent environments in the Galaxy. This energy range is only accessible with ground-based instruments such as Imaging Atmospheric Cherenkov Telescopes (IACTs) that reconstruct the energy and direction of the primary gamma ray by observing the Cherenkov light from the induced extended air showers in Earths atmosphere. The main goals of Galactic VHE gamma-ray science are the identification of individual sources of cosmic rays (CRs), such as supernova remnants (SNRs), and the study of other extreme astrophysical objects at the highest energies, such as gamma-ray binaries and pulsar wind nebulae (PWNe). One of the main challenges is the discrimination between leptonic and hadronic gamma-ray production channels. To that end, the gamma-ray signal from each individual source needs to be brought into context with the multi-wavelength environment of the astrophysical object in question, particularly with observations tracing the density of the surrounding interstellar medium, or synchrotron radiation from relativistic electrons. In this review presented at the European Cosmic Ray Symposium 2014 (ECRS2014), the most recent developments in the field of Galactic VHE gamma-ray science are highlighted, with particular emphasis on SNRs and PWNe.

  2. The Topo-trigger: a new concept of stereo trigger system for imaging atmospheric Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    López-Coto, R.; Mazin, D.; Paoletti, R.; Blanch Bigas, O.; Cortina, J.

    2016-04-01

    Imaging atmospheric Cherenkov telescopes (IACTs) such as the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes endeavor to reach the lowest possible energy threshold. In doing so the trigger system is a key element. Reducing the trigger threshold is hampered by the rapid increase of accidental triggers generated by ambient light (the so-called Night Sky Background NSB). In this paper we present a topological trigger, dubbed Topo-trigger, which rejects events on the basis of their relative orientation in the telescope cameras. We have simulated and tested the trigger selection algorithm in the MAGIC telescopes. The algorithm was tested using MonteCarlo simulations and shows a rejection of 85% of the accidental stereo triggers while preserving 99% of the gamma rays. A full implementation of this trigger system would achieve an increase in collection area between 10 and 20% at the energy threshold. The analysis energy threshold of the instrument is expected to decrease by ~ 8%. The selection algorithm was tested on real MAGIC data taken with the current trigger configuration and no γ-like events were found to be lost.

  3. Investigating D-T Reaction Spectra with the Gas Cherenkov Detector

    NASA Astrophysics Data System (ADS)

    Huff, Michael A.; Kim, Yong Ho; McEvoy, Aaron; Young, Carlton S.; Mack, Joe M.; Herrmann, Hans W.; Horsfield, Colin J.

    2010-11-01

    In this study, a new analysis of the gamma ray spectra of the D-T fusion reaction using a Gas Cherenkov Detector (GCD) is presented. The D-T reaction is an essential process to understand for the future of fusion science. The reaction produces a He^5* nucleus that usually decays into a He^4 + n. It has been seen that this reaction produces a 16.75 MeV gamma ray .0025% of the time. The Gamma Ray History (GRH) group at Los Alamos proposes that there is an even less often occurrence where a gamma ray of around 12 MeV is produced. As the truth of this statement would affect the future potential yield of fusion reactors using D-T fuel, it is worth investigating. D-T spectra were obtained by detecting the produced gamma ray with the GCD at the University of Rochester OMEGA laser facility. A GCD response curve, calculated by the Monte Carlo modeling software ACCEPT, was used to forward convolve theoretical spectra into what the theoretical curves would have looked like in the GCD data. Results are presented.

  4. Detection of D-^3He Fusion γ-Rays using Gas Cherenkov Detectors

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Herrmann, H. W.; Mack, J. M.; Young, C. S.; Hale, G. M.; Evans, S. C.; Sedillo, T. J.; Cahill, A.; Horsfield, C. J.; Rubery, M. S.; Grafil, E.; Stoeffl, W.; Waugh, C.; Rinderknecht, H. G.; Frenje, J. A.; Petrasso, R. D.; Miller, E. Kirk

    2012-10-01

    The high-energy γ-ray from ^3He(d,γ)^5Li reactions has drawn the attention of the nuclear physics and fusion community as a diagnostic signature to study the ^5Li nuclear structure and the D-^3He fusion reaction. In the past, the D-^3He γ-rays have been measured via accelerator-based beam-target experiments and recently in tokamak-based fusion reactors. In this work, we report the detection of D-^3He fusion γ-rays generated from inertial confinement fusion (ICF) implosions at the OMEGA laser facility. The γ-ray signal observed using Gas Cherenkov Detectors (GCD) is proportional to the independently measured 14.7-MeV fusion proton yield and provides a high-bandwidth alternative to fusion protons for D-^3He burn-history measurements. By comparing γ-rays from D-^3He and D-T implosions, we were able to examine (1) similarities in the γ-ray spectra of D-^3He and D-T and (2) disparities in the γ-to-particle branching ratios of D-^3He and D-T. This experimental work motivates further theoretical investigation of the multichannel ^5Li- and ^5He-system.

  5. Optimal strategies for observation of active galactic nuclei variability with Imaging Atmospheric Cherenkov Telescopes

    NASA Astrophysics Data System (ADS)

    Giomi, Matteo; Gerard, Lucie; Maier, Gernot

    2016-07-01

    Variable emission is one of the defining characteristic of active galactic nuclei (AGN). While providing precious information on the nature and physics of the sources, variability is often challenging to observe with time- and field-of-view-limited astronomical observatories such as Imaging Atmospheric Cherenkov Telescopes (IACTs). In this work, we address two questions relevant for the observation of sources characterized by AGN-like variability: what is the most time-efficient way to detect such sources, and what is the observational bias that can be introduced by the choice of the observing strategy when conducting blind surveys of the sky. Different observing strategies are evaluated using simulated light curves and realistic instrument response functions of the Cherenkov Telescope Array (CTA), a future gamma-ray observatory. We show that strategies that makes use of very small observing windows, spread over large periods of time, allows for a faster detection of the source, and are less influenced by the variability properties of the sources, as compared to strategies that concentrate the observing time in a small number of large observing windows. Although derived using CTA as an example, our conclusions are conceptually valid for any IACTs facility, and in general, to all observatories with small field of view and limited duty cycle.

  6. PROBING THE PULSAR ORIGIN OF THE ANOMALOUS POSITRON FRACTION WITH AMS-02 AND ATMOSPHERIC CHERENKOV TELESCOPES

    SciTech Connect

    Linden, Tim; Profumo, Stefano

    2013-07-20

    Recent observations by PAMELA, Fermi-LAT, and AMS-02 have conclusively indicated a rise in the cosmic-ray positron fraction above 10 GeV, a feature which is impossible to mimic under the paradigm of secondary positron production with self-consistent Galactic cosmic-ray propagation models. A leading explanation for the positron fraction rise is an additional source of electron-positron pairs, for example one or more mature, energetic, and relatively nearby pulsars. We point out that any one of two well-known nearby pulsars, Geminga and Monogem, can satisfactorily provide enough positrons to reproduce AMS-02 observations. A smoking-gun signature of this scenario is an anisotropy in the arrival direction of the cosmic-ray electrons and positrons, which may be detectable by existing, or future, telescopes. The predicted anisotropy level is, at present, consistent with limits from Fermi-LAT and AMS-02. We argue that the large collecting area of atmospheric Cherenkov telescopes (ACTs) makes them optimal tools for detecting such an anisotropy. Specifically, we show that much of the proton and {gamma}-ray background which affects measurements of the cosmic-ray electron-positron spectrum with ACTs may be controlled in the search for anisotropies. We conclude that observations using archival ACT data could already constrain or substantiate the pulsar origin of the positron anomaly, while upcoming instruments (such as the Cherenkov Telescope Array) will provide strong constraints on the source of the rising positron fraction.

  7. Front-end electronics and data acquisition system for imaging atmospheric Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Chen, Y. T.; de La Taille, C.; Suomijärvi, T.; Cao, Z.; Deligny, O.; Dulucq, F.; Ge, M. M.; Lhenry-Yvon, I.; Martin-Chassard, G.; Nguyen Trung, T.; Wanlin, E.; Xiao, G.; Yin, L. Q.; Yun Ky, B.; Zhang, L.; Zhang, H. Y.; Zhang, S. S.; Zhu, Z.

    2015-09-01

    In this paper, a front-end electronics based on an application-specific integrated circuit (ASIC) is presented for the future imaging atmospheric Cherenkov telescopes (IACTs). To achieve this purpose, a 16-channel ASIC chip, PARISROC 2 (Photomultiplier ARray Integrated in SiGe ReadOut Chip) is used in the analog signal processing and digitization. The digitized results are sent to the server by a user-defined User Datagram Protocol/Internet Protocol (UDP/IP) hardcore engine through Ethernet that is managed by a FPGA. A prototype electronics fulfilling the requirements of the Wide Field of View Cherenkov Telescope Array (WFCTA) of the Large High Altitude Air Shower Observatory (LHAASO) project has been designed, fabricated and tested to prove the concept of the design. A detailed description of the development with the results of the test measurements are presented. By using a new input structure and a new configuration of the ASIC, the dynamic range of the circuit is extended. A highly precise-time calibrating algorithm is also proposed, verified and optimized for the mass production. The test results suggest that the proposed electronics design fulfills the general specification of the future IACTs.

  8. SU-E-T-186: Feasibility Study of Glass Cherenkov Detector for Prompt Gamma Detection in Proton Therapy

    SciTech Connect

    Lau, A; Chen, Y; Ahmad, S

    2014-06-01

    Purpose: To simulate a Cherenkov glass detector system utilizing prompt gamma (PG) technique to quantify range uncertainties in proton radiation therapy. Methods: A simulation of high energy photons typically produced in proton interactions with materials incident onto a block of Cherenkov glass was performed with the Geant4 toolkit. The standard electromagnetic package was used along with several decay modules (G4Decay, G4DecayPhysics, and G4RadioactiveDecayPhysics) and the optical photon components (G4OpticalPhysics). Our setup included a pencil beam consisting of a hundred thousand 6 MeV photons (approximately the deexcitation energy released from 16O) incident onto a 2.5 ⊗ 2.5 ⊗ 1.5 cm3 of a Cherenkov glass (7.2 g of In2O3 + 90 g cladding, density of 2.82 g/cm3, Zeff = 33.7, index of refraction 1.56). The energy deposited from incident 6 MeV photons as well as secondary electrons and resulting optical photons were recorded. Results: The energy deposited by 6 MeV photons in glass material showed several peaks that included the photoelectric, the single and double escape peaks. About 11% of incident photons interacted with glass material to deposit energy. Most of the photons collected were in the region of double escape peak (approximately 4.98 MeV). The secondary electron spectrum produced from incident photons showed a high energy peak located near 6 MeV and a sharp peak located ∼120 keV with a continuous distribution between these two points. The resulting Cherenkov photons produced showed a continuous energy distribution between 2 and 5 eV with a slight increase in yield beginning about 3 eV. The amount of Cherenkov photons produced per interacting incident 6 MeV photon was ∼240.7. Conclusion: This study suggests the viability of utilizing the Cherenkov glass material as a possible prompt gamma photon detection device. Future work will include optimization of the detector system to maximize photon detection efficiency.

  9. Characteristics of four-channel Cherenkov-type detector for measurements of runaway electrons in the ISTTOK tokamak

    SciTech Connect

    Plyusnin, V. V.; Duarte, P.; Fernandes, H.; Silva, C.

    2010-10-15

    A diagnostics capable of characterizing the runaway and superthermal electrons has been developing on the ISTTOK tokamak. In previous paper, a use of single-channel Cherenkov-type detector with titanium filter for runaway electron studies in ISTTOK was reported. To measure fast electron populations with different energies, a prototype of a four-channel detector with molybdenum filters was designed. Test-stand studies of filters with different thicknesses (1, 3, 7, 10, 20, 50, and 100 {mu}m) have shown that they should allow the detection of electrons with energies higher than 69, 75, 87, 95, 120, 181, and 260 keV, respectively. First results of measurements with the four-channel detector revealed the possibility to measure reliably different fast electrons populations simultaneously.

  10. Design and construction of the front-end electronics data acquisition for the SLD CRID (Cherenkov Ring Imaging Detector)

    SciTech Connect

    Hoeflich, J.; McShurley, D.; Marshall, D.; Oxoby, G.; Shapiro, S.; Stiles, P. ); Spencer, E. . Inst. for Particle Physics)

    1990-10-01

    We describe the front-end electronics for the Cherenkov Ring Imaging Detector (CRID) of the SLD at the Stanford Linear Accelerator Center. The design philosophy and implementation are discussed with emphasis on the low-noise hybrid amplifiers, signal processing and data acquisition electronics. The system receives signals from a highly efficient single-photo electron detector. These signals are shaped and amplified before being stored in an analog memory and processed by a digitizing system. The data from several ADCs are multiplexed and transmitted via fiber optics to the SLD FASTBUS system. We highlight the technologies used, as well as the space, power dissipation, and environmental constraints imposed on the system. 16 refs., 10 figs.

  11. Atmospheric Neutrinos in the MINOS Far Detector

    SciTech Connect

    Howcroft, Caius Leo Frederick

    2004-12-01

    The phenomenon of flavour oscillations of neutrinos created in the atmosphere was first reported by the Super-Kamiokande collaboration in 1998 and since then has been confirmed by Soudan 2 and MACRO. The MINOS Far Detector is the first magnetized neutrino detector able to study atmospheric neutrino oscillations. Although it was designed to detect neutrinos from the NuMI beam, it provides a unique opportunity to measure the oscillation parameters for neutrinos and anti-neutrinos independently. The MINOS Far Detector was completed in August 2003 and since then has collected 2.52 kton-years of atmospheric data. Atmospheric neutrino interactions contained within the volume of the detector are separated from the dominant background from cosmic ray muons. Thirty seven events are selected with an estimated background contamination of less than 10%. Using the detector's magnetic field, 17 neutrino events and 6 anti-neutrino events are identified, 14 events have ambiguous charge. The neutrino oscillation parameters for vμ and $\\bar{v}$μ are studied using a maximum likelihood analysis. The measurement does not place constraining limits on the neutrino oscillation parameters due to the limited statistics of the data set analysed. However, this thesis represents the first observation of charge separated atmospheric neutrino interactions. It also details the techniques developed to perform atmospheric neutrino analyses in the MINOS Far Detector.

  12. The High Altitude Water Cherenlov (HAWC) Gamma ray Detector Response to Atmospheric Electric Field Variations

    NASA Astrophysics Data System (ADS)

    Lara, A.

    2015-12-01

    The High Altitude Water Cherenkov (HAWC) observatory is located at 4100 m a.s.l. in Mexico. HAWC's primary purpose is the study of both: galactic and extra-galactic sources of high energy gamma rays. HAWC consists of 300 large water Cherenkov detectors (WCD), each instrumented with 4 photo-multipliers (PMTs). The HAWC scaler system records the rates of individual PMTs giving the opportunity of study relatively low energy transients as solar energetic particles, the solar modulation of galactic cosmic rays and possible variations of the cosmic ray rate due to atmospheric electric field changes. In this work, we present the observations of scaler rate enhancements associated with thunderstorm activity observed at the HAWC site.In particular, we present preliminary results of the analysis of the time coincidence of the electric field changes and the scaler enhancements.

  13. Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak

    SciTech Connect

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Malinowski, K.; Mirowski, R.; Lotte, Ph.; Gunn, J.; Pascal, J-Y.; Colledani, G.; Basiuk, V.; Goniche, M.; Lipa, M.

    2010-01-15

    The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.

  14. {gamma}-ray 'bang-time' measurements with a gas-Cherenkov detector for inertial-confinement fusion experiments

    SciTech Connect

    Horsfield, C. J.; Caldwell, S. E.; Christensen, C. R.; Evans, S. C.; Mack, J. M.; Sedillo, T.; Young, C. S.; Glebov, V. Yu.

    2006-10-15

    In a laser driven inertial-confinement fusion experiment, bang time is defined as the time between the laser light impinging the target and the peak of the fusion reactions. Bang time is often used to compare computed predictions to experiment. Large laser facilities, such as NIF and LMJ, which are currently under construction, will produce yields far in excess of any previous inertial-confinement fusion experiment. One of the implications of such high yields is that fusion {gamma} rays, which have branching ratios four orders of magnitude less than that of fusion neutrons, may be used to diagnose bang time. This article describes the first of such {gamma}-ray bang-time measurement made using the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The diagnostic used for this was a gas Cherenkov detector. The experimental setup, data and error analyses, and suggested improvements are presented.

  15. Atmospheric neutrinos observed in underground detectors

    NASA Technical Reports Server (NTRS)

    Gaisser, T. K.; Stanev, T.

    1985-01-01

    Atmospheric neutrinos are produced when the primary cosmic ray beam hits the atmosphere and initiates atmospheric cascades. Secondary mesons decay and give rise to neutrinos. The neutrino production was calculated and compared with the neutrino fluxes detected in underground detectors. Contained neutrino events are characterized by observation of an interaction within the fiducial volume of the detector when the incoming particle is not observed. Both the neutrino flux and the containment requirement restrict the energy of the neutrinos observed in contained interactions to less than several GeV. Neutrinos interact with the rock surrounding the detector but only muon neutrino interactions can be observed, as the electron energy is dissipated too fast in the rock. The direction of the neutrino is preserved in the interaction and at energies above 1 TeV the angular resolution is restricted by the scattering of the muon in the rock. The muon rate reflects the neutrino spectrum above some threshold energy, determined by the detector efficiency for muons.

  16. Prototype of a front-end readout ASIC designed for the Water Cherenkov Detector Array in LHAASO

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Wu, W.; Liu, J.; Liang, Y.; Qin, J.; Yu, L.; Liu, S.; An, Q.

    2015-03-01

    The Large High Altitude Air Shower Observatory is in the R&D phase, in which the Water Cherenkov Detector Array is an important part. The signals of Photo-Multiplier Tubes would vary from single photo electron to 4000 photo electrons, and both high precision charge and time measurement is required. To simplify the signal processing chain, the charge-to-time conversion method is employed. A prototype of the front-end readout ASIC is designed and fabricated in Chartered 0.35 μ m CMOS technology, which integrates time disctrimination and converts the input charge information to pulse widths. With Time-to-Digital Converters, both time and charge can be digitized at the same time. We have conducted initial tests on this chip, and the results indicate that a time resolution better than 0.5 ns is achieved over the full dynamic range (1 ~ 4000 photo electrons, corresponding to 0.75 ~ 3000 pC with the threshold of 0.188 pC); the charge resolution is better than 1% with large input amplitudes (500 ~ 4000 photo electrons), and remains better than 15% with a 1 photo electron input amplitude, which is beyond the application requirement.

  17. Electro-optical characterization of MPPC detectors for the ASTRI Cherenkov telescope camera

    NASA Astrophysics Data System (ADS)

    Marano, D.; Belluso, M.; Bonanno, G.; Billotta, S.; Grillo, A.; Garozzo, S.; Romeo, G.; Catalano, O.; La Rosa, G.; Sottile, G.; Impiombato, D.; Giarrusso, S.

    2014-12-01

    This work addresses a systematic and in-depth electro-optical characterization of the Multi-Pixel Photon Counter (MPPC) sensors constituting the camera detection system at the focal plane of the ASTRI telescope prototype. The paper reports the experimental results of a large set of measurements on the MPPC devices in order to provide a reliable qualification of the detector performance and evaluate its compliance with the telescope focal plane requirements. In particular, breakdown voltage, internal gain, dark count rate, cross-talk and extra-charge probability, and absolute photon detection efficiency measurements are performed on the basic sensor device unit as a function of the detector operating conditions.

  18. Transforming Cherenkov radiation in metamaterials

    NASA Astrophysics Data System (ADS)

    Ginis, Vincent; Danckaert, Jan; Veretennicoff, Irina; Tassin, Philippe

    2015-08-01

    In this contribution, we explore the generation of light in transformation-optical media. When charged particles move through a transformation-optical material with a speed larger than the phase velocity of light in the medium, Cherenkov light is emitted. We show that the emitted Cherenkov cone can be modified with longitudinal and transverse stretching of the coordinates. Transverse coordinates stretching alters only the dimensions of the cone, whereas longitudinal stretching also changes the apparent velocity of the charged particle. These results demonstrate that the geometric formalism of transformation optics can be used not only for the manipulation of light beam trajectories, but also for controlling the emission of light, here for describing the Cherenkov cone in an arbitrary anisotropic medium. Subsequently, we illustrate this point by designing a radiator for a ring imaging Cherenkov radiator. Cherenkov radiators are used to identify unknown elementary particles by determining their mass from the Cherenkov radiation cone that is emitted as they pass through the detector apparatus. However, at higher particle momentum, the angle of the Cherenkov cone saturates to a value independent of the mass of the generating particle, making it difficult to effectively distinguish between different particles. Using our transformation optics description, we show how the Cherenkov cone and the cut-off can be controlled to yield a radiator medium with enhanced sensitivity for particle identification at higher momentum [Phys. Rev. Lett. 113, 167402 (2014)].

  19. MACHETE: A transit imaging atmospheric Cherenkov telescope to survey half of the very high energy γ-ray sky

    NASA Astrophysics Data System (ADS)

    Cortina, J.; López-Coto, R.; Moralejo, A.

    2016-01-01

    Current imaging atmospheric Cherenkov telescopes for very high energy γ-ray astrophysics are pointing instruments with a field of view up to a few tens of sq deg. We propose to build an array of two non-steerable (drift) telescopes. Each of the telescopes would have a camera with a FOV of 5 × 60 sq deg oriented along the meridian. About half of the sky drifts through this FOV in a year. We have performed a Monte Carlo simulation to estimate the performance of this instrument. We expect it to survey this half of the sky with an integral flux sensitivity of ˜0.77% of the steady flux of the Crab Nebula in 5 years, an analysis energy threshold of ˜150 GeV and an angular resolution of ˜0.1°. For astronomical objects that transit over the telescope for a specific night, we can achieve an integral sensitivity of 12% of the Crab Nebula flux in a night, making it a very powerful tool to trigger further observations of variable sources using steerable IACTs or instruments at other wavelengths.

  20. Directional Spherical Cherenkov Detector

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Fralick, Gustave C.; Wrbanek, Susan Y.

    2010-01-01

    A proposed radiation-detecting apparatus would provide information on the kinetic energies, directions, and electric charges of highly energetic incident subatomic particles. The apparatus was originally intended for use in measuring properties of cosmic rays in outer space, but could also be adapted to terrestrial uses -- for example, radiation dosimetry aboard high-altitude aircraft and in proton radiation therapy for treatment of tumors.

  1. Volcanoes muon imaging using Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Catalano, O.; Del Santo, M.; Mineo, T.; Cusumano, G.; Maccarone, M. C.; Pareschi, G.

    2016-01-01

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  2. Underground water Cherenkov muon detector array with the Tibet air shower array for gamma-ray astronomy in the 100 TeV region

    NASA Astrophysics Data System (ADS)

    Amenomori, M.; Ayabe, S.; Bi, X. J.; Chen, D.; Cui, S. W.; Danzengluobu; Ding, L. K.; Ding, X. H.; Feng, C. F.; Feng, Zhaoyang; Feng, Z. Y.; Gao, X. Y.; Geng, Q. X.; Guo, H. W.; He, H. H.; He, M.; Hibino, K.; Hotta, N.; Hu, Haibing; Hu, H. B.; Huang, J.; Huang, Q.; Jia, H. Y.; Kajino, F.; Kasahara, K.; Katayose, Y.; Kato, C.; Kawata, K.; Labaciren; Le, G. M.; Li, A. F.; Li, J. Y.; Lu, H.; Lu, S. L.; Meng, X. R.; Mizutani, K.; Mu, J.; Munakata, K.; Nagai, A.; Nanjo, H.; Nishizawa, M.; Ohnishi, M.; Ohta, I.; Onuma, H.; Ouchi, T.; Ozawa, S.; Ren, J. R.; Saito, T.; Saito, T. Y.; Sakata, M.; Sako, T. K.; Sasaki, T.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Takita, M.; Tan, Y. H.; Tateyama, N.; Torii, S.; Tsuchiya, H.; Udo, S.; Wang, B.; Wang, H.; Wang, X.; Wang, Y. G.; Wu, H. R.; Xue, L.; Yamamoto, Y.; Yan, C. T.; Yang, X. C.; Yasue, S.; Ye, Z. H.; Yu, G. C.; Yuan, A. F.; Yuda, T.; Zhang, H. M.; Zhang, J. L.; Zhang, N. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Yi; Zhaxisangzhu; Zhou, X. X.

    2007-06-01

    We propose to build a large water-Cherenkov-type muon-detector array (Tibet MD array) around the 37 000 m2 Tibet air shower array (Tibet AS array) already constructed at 4300 m above sea level in Tibet, China. Each muon detector is a waterproof concrete pool, 6 m wide × 6 m long × 1.5 m deep in size, equipped with a 20 inch-in-diameter PMT. The Tibet MD array consists of 240 muon detectors set up 2.5 m underground. Its total effective area will be 8640 m2 for muon detection. The Tibet MD array will significantly improve gamma-ray sensitivity of the Tibet AS array in the 100 TeV region (10 1000 TeV) by means of gamma/hadron separation based on counting the number of muons accompanying an air shower. The Tibet AS+MD array will have the sensitivity to gamma rays in the 100 TeV region by an order of magnitude better than any other previous existing detectors in the world.

  3. The cosmic ray proton, helium and CNO fluxes in the 100 TeV energy region from TeV muons and EAS atmospheric Cherenkov light observations of MACRO and EAS-TOP

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Alessandro, B.; Antonioli, P.; Arneodo, F.; Bergamasco, L.; Bertaina, M.; Castagnoli, C.; Castellina, A.; Chiavassa, A.; Cini, G.; D'Ettorre Piazzoli, B.; Di Sciascio, G.; Fulgione, W.; Galeotti, P.; Ghia, P. L.; Iacovacci, M.; Mannocchi, G.; Morello, C.; Navarra, G.; Saavedra, O.; Stamerra, A.; Trinchero, G. C.; Valchierotti, S.; Vallania, P.; Vernetto, S.; Vigorito, C.; Ambrosio, M.; Antolini, R.; Baldini, A.; Barbarino, G. C.; Barish, B. C.; Battistoni, G.; Becherini, Y.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bower, C.; Brigida, M.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, D.; Carboni, M.; Caruso, R.; Cecchini, S.; Cei, F.; Chiarella, V.; Chiarusi, T.; Choudhary, B. C.; Coutu, S.; Cozzi, M.; De Cataldo, G.; Dekhissi, H.; De Marzo, C.; De Mitri, I.; Derkaoui, J.; De Vincenzi, M.; Di Credico, A.; Erriquez, O.; Favuzzi, C.; Forti, C.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giorgini, M.; Grassi, M.; Grillo, A.; Guarino, F.; Gustavino, C.; Habig, A.; Hanson, K.; Heinz, R.; Iarocci, E.; Katsavounidis, E.; Katsavounidis, I.; Kearns, E.; Kim, H.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Levin, D. S.; Lipari, P.; Longley, N. P.; Longo, M. J.; Loparco, F.; Maaroufi, F.; Mancarella, G.; Mandrioli, G.; Margiotta, A.; Marini, A.; Martello, D.; Marzari-Chiesa, A.; Mazziotta, M. N.; Michael, D. G.; Monacelli, P.; Montaruli, T.; Monteno, M.; Mufson, S.; Musser, J.; Nicolò, D.; Nolty, R.; Orth, C.; Osteria, G.; Palamara, O.; Patera, V.; Patrizii, L.; Pazzi, R.; Peck, C. W.; Perrone, L.; Petrera, S.; Popa, V.; Rainò, A.; Reynoldson, J.; Ronga, F.; Satriano, C.; Scapparone, E.; Scholberg, K.; Sciubba, A.; Sioli, M.; Sirri, G.; Sitta, M.; Spinelli, P.; Spinetti, M.; Spurio, M.; Steinberg, R.; Stone, J. L.; Sulak, L. R.; Surdo, A.; Tarlé, G.; Togo, V.; Vakili, M.; Walter, C. W.; Webb, R.; EAS-TOP Collaboration

    2004-06-01

    The primary cosmic ray (CR) proton, helium and CNO fluxes in the energy range 80-300 TeV are studied at the National Gran Sasso Laboratories by means of EAS-TOP (Campo Imperatore, 2005 m a.s.l.) and MACRO (deep underground, 3100 m w.e., the surface energy threshold for a muon reaching the detector being Eμth≈1.3 TeV). The measurement is based on: (a) the selection of primaries based on their energy/nucleon (i.e., with energy/nucleon sufficient to produce a muon with energy larger than 1.3 TeV) and the reconstruction of the shower geometry by means of the muons recorded by MACRO in the deep underground laboratories; (b) the detection of the associated atmospheric Cherenkov light (C.l.) signals by means of the C.l. detector of EAS-TOP. The C.l. density at core distance r>100 m is directly related to the total primary energy E0. Proton and helium ("p + He") and proton, helium and CNO ("p + He + CNO") primaries are thus selected at E0≃80 TeV, and at E0≃250 TeV, respectively. Their flux is measured: J p+ He(80 TeV)=(1.8±0.4)×10 -6 m -2 s -1 sr -1 TeV -1, and J p+ He+ CNO(250 TeV)=(1.1±0.3)×10 -7 m -2 s -1 sr -1 TeV -1, their relative weights being: J p+ He/J p+ He+ CNO(250 TeV)=0.78±0.17 . By using the measurements of the proton spectrum obtained from the direct experiments and hadron flux data in the atmosphere, we obtain for the relative weights of the three components at 250 TeV: Jp: JHe: JCNO=(0.20±0.08):(0.58±0.19):(0.22±0.17). This corresponds to the dominance of helium over proton primaries at 100-1000 TeV, and a possible non-negligible contribution from CNO. The lateral distribution of Cherenkov light in Extensive Air Showers (EASs), which is related to the rate of energy deposit of the primary in the atmosphere, is measured for a selected proton and helium primary beam, and good agreement is found when compared with the one calculated with the CORSIKA/QGSJET simulation model.

  4. Cherenkov Source for PMT Calibrations

    NASA Astrophysics Data System (ADS)

    Kaptanoglu, Tanner; SNO+ at UC Berkeley Collaboration

    2013-10-01

    My research is focused on building a deployable source for PMT calibrations in the SNO+ detector. I work for the SNO+ group at UC Berkeley headed by Gabriel Orebi Gann. SNO+ is an addition to the SNO project, and its main goal is to search for neutrinoless double beta decay. The detector will be monitored by over 9500 photomultiplier tubes (PMTs). In order to characterize the PMTs, several calibration sources are being constructed. One of which, the Cherenkov Source, will provide a well-understood source of non-isotropic light for calibrating the detector response. My goal is to design and construct multiple aspects of the Cherenkov Source. However, there are multiple questions that arose with its design. How do we keep the scintillation light inside the Cherenkov source so it does not contaminate calibration? How do we properly build the Cherenkov source: a hollow acrylic sphere with a neck? Can we maintain a clean source throughout these processes? These are some of the problems I have been working on, and will continue to work on, until the deployment of the source. Additionally, I have worked to accurately simulate the physics inside the source, mainly the energy deposition of alphas.

  5. Status of the development of large area photon detectors based on THGEMs and hybrid MPGD architectures for Cherenkov imaging applications

    NASA Astrophysics Data System (ADS)

    Alexeev, M.; Birsa, R.; Bradamante, F.; Bressan, A.; Büchele, M.; Chiosso, M.; Ciliberti, P.; Torre, S. Dalla; Dasgupta, S.; Denisov, O.; Duic, V.; Finger, M.; Finger, M.; Fischer, H.; Giorgi, M.; Gobbo, B.; Gregori, M.; Herrmann, F.; Königsmann, K.; Levorato, S.; Maggiora, A.; Martin, A.; Menon, G.; Steiger, K.; Novy, J.; Panzieri, D.; Pereira, F. A.; Santos, C. A.; Sbrizzai, G.; Schiavon, P.; Schopferer, S.; Slunecka, M.; Sozzi, F.; Steiger, L.; Sulc, M.; Takekawa, S.; Tessarotto, F.; Veloso, J. F. C. A.; Makke, N.

    2016-07-01

    We report about the development status of large area gaseous single photon detectors based on a novel hybrid concept for RICH applications. The hybrid concept combines Thick Gaseous Electron Multipliers (THGEMs) coupled to CsI, working as a photon sensitive pre-amplification stage, and Micromegas, as a multiplication stage. The most recent achievements within the research and development programme consist in the assembly and study of 300 × 300mm2 hybrid photon detectors, the optimization of front-end electronics, and engineering towards large area detectors. Hybrid detectors with an active area of 300 × 300mm2 have been successfully operated in laboratory conditions and at a CERN PS T10 test beam, achieving effective gains in the order of 105 and good time resolution (σ = 7 ns); APV25 front-end chips have been coupled to the detector resulting in noise levels lower than 1000 electrons; the production and characterization of 300 × 600mm2 THGEMs is ongoing. A set of hybrid detectors with 600 × 600mm2 active area is envisaged to upgrade COMPASS RICH-1 at CERN in 2016.

  6. RF Cherenkov picosecond timing technique for high energy physics applications

    SciTech Connect

    Margaryan, Amur; Hashimoto, Osamu; Majewski, Stanislaw; Tang, Liguang

    2008-09-01

    The Cherenkov time-of-propagation (TOP) detector and Cherenkov time-of-flight (TOF) detector in a ?head-on? geometry based on the recently proposed time measuring technique with radio frequency (RF) phototube are considered. Results of the Monte Carlo simulations are presented.

  7. Cyclotron-Cherenkov and Cherenkov instabilities

    SciTech Connect

    Kho, T.H.; Lin, A.T. . Dept. of Physics)

    1990-06-01

    The effect of the conventional Cherenkov instability on the cyclotron-Cherenkov maser is investigated for the case of a relativistic electron beam propagating along a background magnetic field in a dielectric using particle simulations. Both Cherenkov and cyclotron-Cherenkov instabilities are excited when the phase velocity of light in the dielectric is less than the beam velocity. It is demonstrated in the high-power regime, where the cyclotron-Cherenkov mode has the higher growth rate, that the Cherenkov mode has little effect on the nonlinear efficiency of the cyclotron-Cherenkov mode. High efficiency is possible, affirming previous predictions based on single mode calculations. The effect of beam momentum spread is studied.

  8. On the potential of atmospheric Cherenkov telescope arrays for resolving TeV gamma-ray sources in the Galactic plane

    NASA Astrophysics Data System (ADS)

    Ambrogi, L.; De Oña Wilhelmi, E.; Aharonian, F.

    2016-07-01

    The potential of an array of imaging atmospheric Cherenkov telescopes to detect gamma-ray sources in complex regions has been investigated. The basic characteristics of the gamma-ray instrument have been parameterized using simple analytic representations. In addition to the ideal (Gaussian form) point spread function (PSF), the impact of more realistic non-Gaussian PSFs with tails has been considered. Simulations of isolated point-like and extended sources have been used as a benchmark to test and understand the response of the instrument. The capability of the instrument to resolve multiple sources has been analyzed and the corresponding instrument sensitivities calculated. The results are of particular interest for weak gamma-ray emitters located in crowded regions of the Galactic plane, where the chance of clustering of two or more gamma-ray sources within 1 deg is high.

  9. The Atmospheric Muon Charge Ratio at the MINOS Near Detector

    SciTech Connect

    de Jong, J.K.; /IIT, Chicago /Oxford U.

    2011-11-01

    The magnetized MINOS near detector can accurately determine the charge sign of atmospheric muons, this facilitates a measurement of the atmospheric muon charge ratio. To reduce the systematic error associated with geometric bias and acceptance we have combined equal periods of data obtained with opposite magnetic field polarities. We report a charge ratio of 1.2666 {+-} 0.0015(stat.){sub -0.0088}{sup +0.0096}(syst.) at a mean E{sub {mu},0{sup cos}}({theta}) = 63 GeV. This measurement is consistent with the world average but significantly lower than the earlier observation at the MINOS far detector. This increase is shown to be consistent with the hypothesis that a greater fraction of the observed muons arise from kaon decay within the cosmic ray shower.

  10. Wide-angle cherenkov telescope prototype preliminary data

    NASA Astrophysics Data System (ADS)

    Timofeev, Lev; Anatoly, Ivanov

    2016-07-01

    This report presents an observation method of Cherenkov light from extensive air showers (EAS) generated by cosmic rays (CRs) above 10^16eV and preliminary observations. The interest in Cherenkov light differential detectors of EAS is caused by the possibility to measure the depth of cascade maximum, Xmax, and/or the shower age via angular and temporal distributions of the Cherenkov signal. In particular, it was shown using EAS model simulations that the pulse width measured at the periphery of the shower, r > 300 m, at sea level is pronouncedly connected with Xmax. Cherenkov detector is a wide-angle telescope working in coincidence with scintillation detectors, integral and differential Cherenkov detectors Yakutsk complex EAS.

  11. A study of atmospheric neutrinos with the IMB detector

    NASA Technical Reports Server (NTRS)

    Losecco, J. M.; Bionta, R. M.; Blewitt, G.; Bratton, C. B.; Casper, D.; Chrysicopoulou, P.; Claus, R.; Cortez, B. G.; Errede, S.; Foster, G. W.

    1985-01-01

    A sample of 401 contained neutrino interactions collected in the 3300 metric ton fiducial mass IMB detector was used to study neutrino oscillations, geomagnetic modulation of the flux and to search for point sources. The majority of these events are attributed to neutrino interactions. For the most part, these neutrinos are believed to originate as tertiary products of cosmic ray interactions in the atmosphere. The neutrinos are a mixture of v sub e and v sub micron.

  12. Atmospheric electron neutrinos in the MINOS far detector

    SciTech Connect

    Speakman, Benjamin Phillip

    2007-01-01

    Neutrinos produced as a result of cosmic-ray interactions in the earth's atmosphere offer a powerful probe into the nature of this three-membered family of low-mass, weakly-interacting particles. Ten years ago, the Super-Kamiokande Experiment has confirmed earlier indications that neutrinos undergo lepton-flavor oscillations during propagation, proving that they are massive contrary to the previous Standard Model assumptions. The Soudan Underground Laboratory, located in northern Minnesota, was host to the Soudan2 Experiment, which has made important contributions to atmospheric neutrino research. This same lab has more recently been host to the MINOS far detector, a neutrino detector which serves as the downstream element of an accelerator-based long-baseline neutrino-oscillation experiment. This thesis has examined 418.5 live days of atmospheric neutrino data (fiducial exposure of 4.18 kton-years) collected in the MINOS far detector prior to the activation of the NuMI neutrino beam, with a specific emphasis on the investigation of electron-type neutrino interactions. Atmospheric neutrino interaction candidates have been selected and separated into showering or track-like events. The showering sample consists of 89 observed events, while the track-like sample consists of 112 observed events. Based on the Bartol atmospheric neutrino flux model of Barr et al. plus a Monte Carlo (MC) simulation of interactions in the MINOS detector, the expected yields of showering and track-like events in the absence of neutrino oscillations are 88.0 ± 1.0 and 149.1 ± 1.0 respectively (where the uncertainties reflect only the limited MC statistics). Major systematic uncertainties, especially those associated with the flux model, are cancelled by forming a double ratio of these observed and expected yields: R$data\\atop{trk/shw}$/R$MC\\atop{trk/shw}$ = 0.74$+0.12\\atop{-1.0}$(stat.) ± 0.04 (syst.) This double ratio should be equal to unity in the absence of oscillations, and the

  13. The History of Ground-Based Very High Energy Gamma-Ray Astrophysics with the Atmospheric Air Cherenkov Telescope Technique

    NASA Astrophysics Data System (ADS)

    Mirzoyan, Razmik

    2013-06-01

    In the recent two decades the ground-based technique of imaging atmosphericescopes has established itself as a powerful new discipline in science. As of today some ˜ 150 sources of gamma rays of very different types, of both galactic and extragalactic origin, have been discovered due to this technique. The study of these sources is providing clues to many basic questions in astrophysics, astro-particle physics, physics of cosmic rays and cosmology. The current generation of telescopes, despite the young age of the technique, offers a solid performance. The technique is still maturing, leading to the next generation large instrument known under the name Cherenkov Telescope Array. The latter's sensitivity will be an order of magnitude higher than that of the currently best instruments VERITAS, H.E.S.S. and MAGIC. This article is devoted to outlining the milestones in a long history that step-by-step have given shape to this technique and have brought about today's successful source marathon.

  14. NICHE: The non-imaging Cherenkov array

    NASA Astrophysics Data System (ADS)

    Bergman, Douglas; Krizmanic, John

    2013-02-01

    The accurate measurement of the Cosmic Ray (CR) nuclear composition around and above the Knee (~ 1015.5 eV) has been difficult due to uncertainties inherent to the measurement techniques and/or dependence on hadronic Monte Carlo simulation models required to interpret the data. Measurement of the Cherenkov air shower signal, calibrated with air fluorescence measurements, offers a methodology to provide an accurate measurement of the nuclear composition evolution over a large energy range. NICHE will use an array of widely-spaced, non-imaging Cherenkov counters to measure the amplitude and time-spread of the air shower Cherenkov signal to extract CR nuclear composition measurements and to cross-calibrate the Cherenkov energy and composition measurements with TA/TALE fluorescence and surface detector measurements.

  15. The Lunar Atmosphere as a Cosmic-Ray Detector

    NASA Technical Reports Server (NTRS)

    Wilson, T. L.

    2007-01-01

    The recent discovery of a tenuous sodium (Na) atmosphere on the Moon and Mercury has renewed interest in studying the lunar atmosphere since the physics involved for the two bodies is thought to be of similar nature. Na came as a surprise because it had been missed by in situ UV measurements made during the Apollo program. The new lunar observations involve the visible D1 (5896 ) and D2 (5890 ) wavelengths which are highly efficient at scattering sunlight. Although its lunar source and morphology is still not completely understood, Na is present as a collisionless exosphere - apparently in the form of a cometary-type coma with a tail that can extend hundreds of lunar radii during Leonid showers. The global shape of the atmosphere, in particular for the shaded antisolar side, has been modelled by Smyth. Since planetary atmospheres can be used as cosmic-ray (CR) spectrometers by means of their fluorescence excited by CR-induced air shower particles, the subject of the Moon s atmosphere as a CR detector will be discussed here.

  16. Controlling Cherenkov Radiation with Transformation-Optical Metamaterials

    NASA Astrophysics Data System (ADS)

    Ginis, Vincent; Danckaert, Jan; Veretennicoff, Irina; Tassin, Philippe

    2014-10-01

    In high energy physics, unknown particles are identified by determining their mass from the Cherenkov radiation cone that is emitted as they pass through the detector apparatus. However, at higher particle momentum, the angle of the Cherenkov cone saturates to a value independent of the mass of the generating particle, making it difficult to effectively distinguish between different particles. Here, we show how the geometric formalism of transformation optics can be applied to describe the Cherenkov cone in an arbitrary anisotropic medium. On the basis of these results, we propose a specific anisotropic metamaterial to control Cherenkov radiation, leading to enhanced sensitivity for particle identification at higher momentum.

  17. Performance Characterization of the Atmospheric Velocity Imaging Detector (AVID)

    NASA Astrophysics Data System (ADS)

    Gardiner, J. D.

    2015-12-01

    Central to the improvement of upper atmospheric models is a dramatic expansion in current understanding of the coupling and dynamics within the Ionosphere / Thermosphere (IT) system. Conventional in situ measurement techniques using energy scanning and analog current detection are limited by poor sensitivity and have produced incomplete datasets. The Atmospheric Velocity Imaging Detector (AVID) overcomes the limitations of current instruments through the use of two orthogonally mounted Imaging Dispersive Energy Analyzers (IDEAs) which share a single pulse-counting ion detector. The second-generation IDEA design uses inexpensive and lightweight printed circuit boards, with parallel exposed copper traces connected via resistors to generate a highly uniform deflection field. This arrangement allows AVID to make accurate and sensitive in situ measurements of neutral wind / ion drift velocities, temperature, density, and composition, with no voltage scanning required. We present results from the development progress of AVID, through laboratory testing and characterization of an individual IDEA unit when exposed to angle-resolved hypervelocity ion beams emulating 4.7 eV O and 8.2 eV N2. Through these measurements, the projected performance of the AVID system and recently developed image processing algorithms are compared against SIMION ion trajectory calculations and Monte Carlo simulations.

  18. Development of a custom on-line ultrasonic vapour analyzer/flowmeter for the ATLAS inner detector, with application to gaseous tracking and Cherenkov detectors

    NASA Astrophysics Data System (ADS)

    Bates, R.; Battistin, M.; Berry, S.; Berthoud, J.; Bitadze, A.; Bonneau, P.; Botelho-Direito, J.; Bousson, N.; Boyd, G.; Bozza, G.; Da Riva, E.; Degeorge, C.; DiGirolamo, B.; Doubek, M.; Godlewski, J.; Hallewell, G.; Katunin, S.; Lombard, D.; Mathieu, M.; McMahon, S.; Nagai, K.; Perez-Rodriguez, E.; Rossi, C.; Rozanov, A.; Vacek, V.; Vitek, M.; Zwalinski, L.

    2013-01-01

    Precision sound velocity measurements can simultaneously determine binary gas composition and flow. We have developed an analyzer with custom electronics, currently in use in the ATLAS inner detector, with numerous potential applications. The instrument has demonstrated ~ 0.3% mixture precision for C3F8/C2F6 mixtures and < 10-4 resolution for N2/C3F8 mixtures. Moderate and high flow versions of the instrument have demonstrated flow resolutions of ± 2% of full scale for flows up to 250 l min-1, and ± 1.9% of full scale for linear flow velocities up to 15 m s-1 the latter flow approaching that expected in the vapour return of the thermosiphon fluorocarbon coolant recirculator being built for the ATLAS silicon tracker.

  19. Search for Proton Decay via {ital p} {r_arrow} {ital e}{sup +}{ital {pi}}{sup 0} in a Large Water Cherenkov Detector

    SciTech Connect

    Shiozawa, M.; Fukuda, Y.; Hayakawa, T.; Ichihara, E.; Inoue, K.; Ishihara, K.; Ishino, H.; Itow, Y.; Kajita, T.; Kameda, J.; Kasuga, S.; Kobayashi, K.; Kobayashi, Y.; Koshio, Y.; Miura, M.; Nakahata, M.; Nakayama, S.; Okada, A.; Oketa, M.; Okumura, K.; Ota, M.; Sakurai, N.; Suzuki, Y.; Takeuchi, Y.; Totsuka, Y.; Yamada, S.; Earl, M.; Habig, A.; Kearns, E.; Messier, M.D.; Scholberg, K.; Stone, J.L.; Sulak, L.R.; Walter, C.W.; Goldhaber, M.; Barszczak, T.; Gajewski, W.; Halverson, P.G.; Hsu, J.; Kropp, W.R.; Price, L.R.; Reines, F.; Sobel, H.W.; Vagins, M.R.; Haines, T.J.; Kielczewska, D.; Ganezer, K.S.; Keig, W.E.; Ellsworth, R.W.; Tasaka, S.; Flanagan, J.W.; Kibayashi, A.; Learned, J.G.; Matsuno, S.; Stenger, V.; Takemori, D.; Ishii, T.; Kanzaki, J.; Kobayashi, T.; Nakamura, K.; Nishikawa, K.; Oyama, Y.; Sakai, A.; Sakuda, M.; Sasaki, O.; Echigo, S.; Kohama, M.; Suzuki, A.T.; Haines, T.J.; Blaufuss, E.; and others

    1998-10-01

    We have searched for proton decay via p{r_arrow}e{sup +}{pi}{sup 0} using data from a 25.5 kton{center_dot}yr exposure of the Super-Kamiokande detector. We find no candidate events with an expected background induced by atmospheric neutrinos of 0.1thinspthinspevents. From these data, we set a lower limit on the partial lifetime of the proton {tau}/B{sub p{r_arrow}e{sup +}{pi}{sup 0}} to be 1.6{times}10{sup 33} years at a 90{percent} confidence level. {copyright} {ital 1998} {ital The American Physical Society }

  20. Atmospheric tau neutrinos in a multikiloton liquid argon detector

    SciTech Connect

    Conrad, Janet; Gouvea, Andre de; Shalgar, Shashank; Spitz, Joshua

    2010-11-01

    An ultralarge liquid argon time projection chamber based neutrino detector will have the uncommon ability to detect atmospheric {nu}{sub {tau}}/{nu}{tau} events. This paper discusses the most promising modes for identifying charged current {nu}{sub {tau}}/{nu}{tau}, and shows that, with simple kinematic cuts, {approx}30 {nu}{sub {tau}}+{nu}{tau} interactions can be isolated in a 100 kt{center_dot}yr exposure, with greater than 4{sigma} significance. This sample is sufficient to perform flux-averaged total cross-section and cross-section shape parametrization measurements--the first steps toward using {nu}{sub {tau}}/{nu}{tau} to search for physics beyond the standard model.

  1. CPT conservation and atmospheric neutrinos in the MINOS far detector

    SciTech Connect

    Becker, Bernard Raymond

    2006-02-01

    The MINOS Far Detector is a 5400 ton iron calorimeter located at the Soudan state park in Soudan Minnesota. The MINOS far detector can observe atmospheric neutrinos and separate charge current νμ and $\\bar{v}$μ interactions by using a 1.4 T magnetic field to identify the charge of the produced muon. The CPT theorem requires that neutrinos and anti-neutrinos oscillate in the same way. In a fiducial exposure of 5.0 kilo-ton years a total of 41 candidate neutrino events are observed with an expectation of 53.1 ± 7.6(system.) ± 7.2(stat.) unoscillated events or 31.6 ± 4.7(system.) ± 5.6(stat.) events with Δm2 = 2.4 x 10-3 eV2, sin2(2θ) = 1.0 as oscillation parameters. These include 28 events which can have there charge identified with high confidence. These 28 events consist of 18 events consistent with being produced by νμ and 10 events being consistent with being produced by $\\bar{v}$μ. No evidence of CPT violation is observed.

  2. Atmospheric Neutrino Induced Muons in the MINOS Far Detector

    SciTech Connect

    Rahman, Aftabur Dipu

    2007-02-01

    The Main Injector Neutrino Oscillation Search (MINOS) is a long baseline neutrino oscillation experiment. The MINOS Far Detector, located in the Soudan Underground Laboratory in Soudan MN, has been collecting data since August 2003. The scope of this dissertation involves identifying the atmospheric neutrino induced muons that are created by the neutrinos interacting with the rock surrounding the detector cavern, performing a neutrino oscillation search by measuring the oscillation parameter values of Δm$2\\atop{23}$ and sin223, and searching for CPT violation by measuring the charge ratio for the atmospheric neutrino induced muons. A series of selection cuts are applied to the data set in order to extract the neutrino induced muons. As a result, a total of 148 candidate events are selected. The oscillation search is performed by measuring the low to high muon momentum ratio in the data sample and comparing it to the same ratio in the Monte Carlo simulation in the absence of neutrino oscillation. The measured double ratios for the ''all events'' (A) and high resolution (HR) samples are RA = R$data\\atop{low/high}$/R$MC\\atop{low/high}$ = 0.60$+0.11\\atop{-0.10}$(stat) ± 0.08(syst) and RHR = R$data\\atop{low/high}$/R$MC\\atop{low/high}$ = 0.58$+0.14\\atop{-0.11}$(stat) ± 0.05(syst), respectively. Both event samples show a significant deviation from unity giving a strong indication of neutrino oscillation. A combined momentum and zenith angle oscillation fit is performed using the method of maximum log-likelihood with a grid search in the parameter space of Δm2 and sin2 2θ. The best fit point for both event samples occurs at Δm$2\\atop{23}$ = 1.3 x 10-3 eV2, and sin223 = 1. This result is compatible with previous measurements from the Super Kamiokande experiment and Soudan 2 experiments. The MINOS Far Detector is the first underground neutrino

  3. HAWC: The high altitude water Cherenkov observatory

    NASA Astrophysics Data System (ADS)

    Goodman, Jordan A.

    2013-02-01

    The High Altitude Water Cherenkov Observatory (HAWC) is currently being deployed at 4100m above sea level on the Vulcan Sierra Negra near Puebla, Mexico. The HAWC observatory will consist of 250-300 Water Cherenkov Detectors totaling approximately 22,000 m2 of instrumented area. The water Cherenkov technique allows HAWC to have a nearly 100% duty cycle and large field of view, making the HAWC observatory an ideal instrument for the study of transient phenomena. With its large effective area, excellent angular and energy resolutions, and efficient gamma-hadron separation, HAWC will survey the TeV gamma-ray sky, measure spectra of galactic sources from 1 TeV to beyond 100 TeV, and map galactic diffuse gamma ray emission. The science goals, instrument performance and status of the HAWC observatory will be presented.

  4. The High-Altitude Water Cherenkov Observatory: First Light

    NASA Astrophysics Data System (ADS)

    Weisgarber, Thomas

    2013-04-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is under construction at Sierra Negra in the state of Puebla in Mexico. Operation began in September 2012, with the first 30 out of the final 300 water Cherenkov detectors deployed and in data acquisition. The HAWC Observatory is designed to record particle air showers from gamma rays and cosmic rays with TeV energies. Though the detector is only 10% complete, HAWC is already the world's largest water Cherenkov detector in the TeV band. In this presentation, I will summarize the performance of the detector to date and discuss preliminary observations of cosmic-ray and gamma-ray sources. I will also describe deployment plans for the remainder of the detector and outline prospects for TeV observations in the coming year.

  5. Atmospheric neutrino observations in the MINOS far detector

    SciTech Connect

    Chapman, John Derek

    2007-09-01

    This thesis presents the results of atmospheric neutrino observations from a 12.23 ktyr exposure of the 5.42 kt MINOS Far Detector between 1st August 2003 until 1st March 2006. The separation of atmospheric neutrino events from the large background of cosmic muon events is discussed. A total of 277 candidate contained vertex v/$\\bar{v}$μ CC data events are observed, with an expectation of 354.4±47.4 events in the absence of neutrino oscillations. A total of 182 events have clearly identified directions, 77 data events are identified as upward going, 105 data events are identified as downward going. The ratio between the measured and expected up/down ratio is: R$data\\atop{u/d}$/R$MC\\atop{u/d}$ = 0.72$+0.13\\atop{-0.11}$(stat.)± 0.04 (sys.). This is 2.1σ away from the expectation for no oscillations. A total of 167 data events have clearly identified charge, 112 are identified as vμ events, 55 are identified as $\\bar{v}$μ events. This is the largest sample of charge-separated contained-vertex atmospheric neutrino interactions so far observed. The ratio between the measured and expected $\\bar{v}$μ/vμ ratio is: R$data\\atop{$\\bar{v}$v}$/ R$MC\\atop{$\\bar{v}$v}$ = 0.93 $+0.19\\atop{-0.15}$ (stat.) ± 0.12 (sys.). This is consistent with vμ and $\\bar{v}$μ having the same oscillation parameters. Bayesian methods were used to generate a log(L/E) value for each event. A maximum likelihood analysis is used to determine the allowed regions for the oscillation parameters Δm$2\\atop{32}$ and sin223. The likelihood function uses the uncertainty in log(L/E) to bin events in order to extract as much information from the data as possible. This fit rejects the null oscillations hypothesis at the 98% confidence level. A fit to independent vμ and $\\bar{v}$μ oscillation assuming maximal mixing for both is also performed. The projected

  6. Detection of Atmospheric Muon Neutrinoswith the IceCube 9-String Detector

    SciTech Connect

    IceCube Collaboration; Klein, Spencer; Achterberg, A.

    2007-05-12

    The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino detector under construction at the geographic South Pole. The dominant population of neutrinos detected in IceCube is due to meson decay in cosmic-ray air showers. These atmospheric neutrinos are relatively well understood and serve as a calibration and verification tool for the new detector. In 2006, the detector was approximately 10% completed, and we report on data acquired from the detector in this configuration. We observe an atmospheric neutrino signal consistent with expectations, demonstrating that the IceCube detector is capable of identifying neutrino events. In the first 137.4 days of livetime, 234 neutrino candidates were selected with an expectation of 211 {+-} 76.1(syst.) {+-} 14.5(stat.) events from atmospheric neutrinos.

  7. Detecting EHE Cosmic Rays Using Cherenkov Light

    NASA Astrophysics Data System (ADS)

    Bergman, Douglas

    2011-04-01

    Cherenkov light has been used to detect gamma rays in the TeV energy range using an imaging technique and cosmic rays in the PeV energy range using a non-imaging technique. We would like to extend the use of the non-imaging technique up to nearly 1 EeV. At these energies the technique can be used in conjunction with fluorescence detection of cosmic rays, allowing for hybrid reconstruction of shower geometries and cross calibration of energy scales. We envision using an array of Cherenkov detectors as part of the Telescope Array (TA) Low Energy extension (TALE), extending the energy range of the detector down to the Knee of the cosmic ray energy spectrum.

  8. Coherent Cherenkov radiation from cosmic-ray-induced air showers.

    PubMed

    de Vries, K D; van den Berg, A M; Scholten, O; Werner, K

    2011-08-01

    Very energetic cosmic rays entering the atmosphere of Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a new effect: Because of the index of refraction of air, this radiation is collimated in a Cherenkov cone. To express the difference from usual Cherenkov radiation, i.e., the emission from a fast-moving electric charge, we call this magnetically induced Cherenkov radiation. We indicate its signature and possible experimental verification.

  9. Wavelength-shifted Cherenkov radiators

    NASA Technical Reports Server (NTRS)

    Krider, E. P.; Jacobson, V. L.; Pifer, A. E.; Polakos, P. A.; Kurz, R. J.

    1976-01-01

    The scintillation and Cherenkov responses of plastic Cherenkov radiators containing different wavelength-shifting fluors in varying concentrations have been studied in beams of low energy protons and pions. For cosmic ray applications, where large Cherenkov to scintillation ratios are desired, the optimum fluor concentrations are 0.000025 by weight or less.

  10. Compact cosmic ray detector for unattended atmospheric ionization monitoring.

    PubMed

    Aplin, K L; Harrison, R G

    2010-12-01

    Two vertical cosmic ray telescopes for atmospheric cosmic ray ionization event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B's event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located comparison of both telescopes exposed to atmospheric ionization showed a linear relationship between their event rates. PMID:21198037

  11. Compact cosmic ray detector for unattended atmospheric ionization monitoring

    SciTech Connect

    Aplin, K. L.; Harrison, R. G.

    2010-12-15

    Two vertical cosmic ray telescopes for atmospheric cosmic ray ionization event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B's event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located comparison of both telescopes exposed to atmospheric ionization showed a linear relationship between their event rates.

  12. A new air-Cherenkov array at the South Pole

    NASA Astrophysics Data System (ADS)

    Dickinson, J. E.; Gill, J. R.; Hart, S. P.; Hill, G. C.; Hinton, J. A.; Lloyd-Evans, J.; Potter, D.; Pryke, C.; Rochester, K.; Schwarz, R.; Watson, A. A.

    2000-01-01

    VULCAN comprises a 9 element array of air-Cherenkov radiation detectors established at the South Pole. VULCAN operates in coincidence with the air-shower array SPASE-2 and the two Antarctic Muon And Neutrino Detector Arrays, AMANDA A and B, supplementing the data gathered by these instruments with a measurement of the lateral distribution of air-Cherenkov light from extensive air-showers. An overview of the aims and methods of the whole coincidence experiment (SPASE-2, VULCAN and AMANDA) can be found in an accompanying paper (Dickinson et al., Nucl. Instr. and Meth. A (1999), to be published).

  13. Strategy implementation for the CTA Atmospheric monitoring program

    NASA Astrophysics Data System (ADS)

    Doro, Michele; Daniel, Michael; de los Reyes, Raquel; Gaug, Markus; Maccarone, Maria Concetta

    2015-03-01

    The Cherenkov Telescope Array (CTA) is the next generation facility of Imaging Atmospheric Cherenkov Telescopes. It reaches unprecedented sensitivity and energy resolution in very-high-energy gamma-ray astronomy. CTA detects Cherenkov light emitted within an atmospheric shower of particles initiated by cosmic-gamma rays or cosmic rays entering the Earth's atmosphere. From the combination of images the Cherenkov light produces in the telescopes, one is able to infer the primary particle energy and direction. A correct energy estimation can be thus performed only if the local atmosphere is well characterized. The atmosphere not only affects the shower development itself, but also the Cherenkov photon transmission from the emission point in the particle shower, at about 10-20 km above the ground, to the detector. Cherenkov light on the ground is peaked in the UV-blue region, and therefore molecular and aerosol extinction phenomena are important. The goal of CTA is to control systematics in energy reconstruction to better than 10%. For this reason, a careful and continuous monitoring and characterization of the atmosphere is required. In addition, CTA will be operated as an observatory, with data made public along with appropriate analysis tools. High-level data quality can only be ensured if the atmospheric properties are consistently and continuously taken into account. In this contribution, we concentrate on discussing the implementation strategy for the various atmospheric monitoring instruments currently under discussion in CTA. These includes Raman lidars and ceilometers, stellar photometers and others available both from commercial providers and public research centers.

  14. Space Radiation Detector with Spherical Geometry

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D. (Inventor); Fralick, Gustave C. (Inventor); Wrbanek, Susan Y. (Inventor)

    2011-01-01

    A particle detector is provided, the particle detector including a spherical Cherenkov detector, and at least one pair of detector stacks. In an embodiment of the invention, the Cherenkov detector includes a sphere of ultraviolet transparent material, coated by an ultraviolet reflecting material that has at least one open port. The Cherenkov detector further includes at least one photodetector configured to detect ultraviolet light emitted from a particle within the sphere. In an embodiment of the invention, each detector stack includes one or more detectors configured to detect a particle traversing the sphere.

  15. Space Radiation Detector with Spherical Geometry

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D. (Inventor); Fralick, Gustave C. (Inventor); Wrbanek, Susan Y. (Inventor)

    2012-01-01

    A particle detector is provided, the particle detector including a spherical Cherenkov detector, and at least one pair of detector stacks. In an embodiment of the invention, the Cherenkov detector includes a sphere of ultraviolet transparent material, coated by an ultraviolet reflecting material that has at least one open port. The Cherenkov detector further includes at least one photodetector configured to detect ultraviolet light emitted from a particle within the sphere. In an embodiment of the invention, each detector stack includes one or more detectors configured to detect a particle traversing the sphere.

  16. Atmospheric pressure helium afterglow discharge detector for gas chromatography

    DOEpatents

    Rice, Gary; D'Silva, Arthur P.; Fassel, Velmer A.

    1986-05-06

    An apparatus for providing a simple, low-frequency electrodeless discharge system for atmospheric pressure afterglow generation. A single quartz tube through which a gas mixture is passed is extended beyond a concentric electrode positioned thereabout. A grounding rod is placed directly above the tube outlet to permit optical viewing of the discharge between the electrodes.

  17. Atmospheric pressure helium afterglow discharge detector for gas chromatography

    DOEpatents

    Rice, G.; D'Silva, A.P.; Fassel, V.A.

    1985-04-05

    An apparatus for providing a simple, low-frequency, electrodeless discharge system for atmospheric pressure afterglow generation. A single quartz tube through which a gas mixture is passed is extended beyond a concentric electrode positioned thereabout. A grounding rod is placed directly above the tube outlet to permit optical viewing of the discharge between the electrodes.

  18. The Tunka detector complex: from cosmic-ray to gamma-ray astronomy

    NASA Astrophysics Data System (ADS)

    Budnev, N.; Astapov, I.; Barbashina, N.; Bogdanov, A.; Bogorodskii, D.; Boreyko, V.; Büker, M.; Brückner, M.; Chiavassa, A.; Chvalaev, O.; Gress, O.; Gress, T.; Dyachok, A.; Epimakhov, S.; Gafatov, A.; Gorbunov, N.; Grebenyuk, V.; Grinuk, A.; Haungs, A.; Hiller, R.; Horns, D.; Huege, T.; Ivanova, A.; Kalinin, A.; Karpov, N.; Kalmykov, N.; Kazarina, Y.; Kindin, V.; Kirichkov, N.; Kiryuhin, S.; Kleifges, M.; Kokoulin, R.; Komponiest, K.; Konstantinov, A.; Konstantinov, E.; Korobchenko, A.; Korosteleva, E.; Kostunin, D.; Kozhin, V.; Krömer, O.; Kunnas, M.; Kuzmichev, L.; Lenok, V.; Lubsandorzhiev, B.; Lubsandorzhiev, N.; Mirgazov, R.; Mirzoyan, R.; Monkhoev, R.; Nachtigall, R.; Pakhorukov, A.; Panasyuk, M.; Pankov, L.; Petrukhin, A.; Platonov, V.; Poleschuk, V.; Popova, E.; Porelli, A.; Prosin, V.; Ptuskin, V.; Rubtsov, G.; Rühle, C.; Samoliga, V.; Satunin, P.; Savinov, V.; Saunkin, A.; Schröder, F.; Semeney, Yu; Shaibonov (junior, B.; Silaev, A.; Silaev (junior, A.; Skurikhin, A.; Slucka, V.; Spiering, C.; Sveshnikova, L.; Tabolenko, V.; Tkachenko, A.; Tkachev, L.; Tluczykont, M.; Voronin, D.; Wischnewski, R.; Zagorodnikov, A.; Zurbanov, V.; Yashin, I.

    2015-08-01

    TAIGA stands for “Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy” and is a project to build a complex, hybrid detector system for ground-based gamma- ray astronomy from a few TeV to several PeV, and for cosmic-ray studies from 100 TeV to 1 EeV. TAIGA will search for ”PeVatrons” (ultra-high energy gamma-ray sources) and measure the composition and spectrum of cosmic rays in the knee region (100 TeV - 10 PeV) with good energy resolution and high statistics. TAIGA will include Tunka-HiSCORE (an array of wide-angle air Cherenkov stations), an array of Imaging Atmospheric Cherenkov Telescopes, an array of particle detectors, both on the surface and underground, and the TUNKA-133 air Cherenkov array.

  19. Characterization of avalanche photodiodes for lidar atmospheric return signal detectors

    NASA Technical Reports Server (NTRS)

    Antill, C. W., Jr.; Holloway, R. M.

    1988-01-01

    Results are presented from tests to characterize noise, dark current, overload, and gain versus bias, relationships of ten avalanche photodiodes. The advantages of avalanche photodiodes over photomultiplier tubes for given laser wavelengths and return signal amplitudes are outlined. The relationship between responsivity and temperature and dark current and temperature are examined. Also, measurements of the noise equivalent power, the excess noise factor, and linearity are given. The advantages of using avalanche photodiodes in the Lidar Atmospheric Sensing Experiment and the Lidar In-Space Technology Experiment are discussed.

  20. Electron-bombarded CCD detectors for ultraviolet atmospheric remote sensing

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.; Opal, C. B.

    1983-01-01

    Electronic image sensors based on charge coupled devices operated in electron-bombarded mode, yielding real-time, remote-readout, photon-limited UV imaging capability are being developed. The sensors also incorporate fast-focal-ratio Schmidt optics and opaque photocathodes, giving nearly the ultimate possible diffuse-source sensitivity. They can be used for direct imagery of atmospheric emission phenomena, and for imaging spectrography with moderate spatial and spectral resolution. The current state of instrument development, laboratory results, planned future developments and proposed applications of the sensors in space flight instrumentation is described.

  1. Oscillation of Very Low Energy Atmospheric Neutrinos

    SciTech Connect

    Peres, Orlando L. G.

    2010-03-30

    We discuss the oscillation effects of sub-sub-GeV atmospheric neutrinos, the sample with energies E < or approx. 100 MeV. The energy spectra of the e-like events in water Cherenkov detectors are computed and dependence of the spectra on the 2-3 mixing angle, theta{sub 23}, the 1-3 mixing and CP-violation phase are studied.

  2. Massive Cherenkov neutrino facilities…their evolution, their future: Twenty-five years at these International Neutrino Conferences

    NASA Astrophysics Data System (ADS)

    Sulak, Lawrence R.

    2005-06-01

    This review traces the evolution of massive water Cherenkov tracking calorimeters. Pioneering concepts, first presented in this conference a quarter of a century ago, have led to 1) IMB, the first large detector (10kT), which was designed primarily to search for proton decay, and secondarily to be sensitive to supernova neutrinos and atmospheric oscillations, and 2) Dumand, an attempt to initiate the search for TeV astrophysical neutrinos with a prototype for a 1 km3 telescope. The concepts and initial work on IMB influenced subsequent detectors: Kamiokande, Super-K, SNO, and, in part, Kamland. These detectors have to their credit the elucidation of the physics of atmospheric, solar, reactor and supernova neutrinos. With the advent of the K2K beam, controlled accelerator neutrinos confirm the atmospheric studies. The path breaking developments of Dumand now are incorporated in the high-volume Amanda and Antares detectors, as well as their sequels, IceCube and the proposed Cubic Kilometer detector. The future (ultimate?) facilities have new physics challenges: A high-resolution megaton detector, eventually coupled with an intense accelerator neutrino source, is critical for precision studies of neutrino oscillation parameters and for the potential discovery of CP violation in the lepton sector. The Gigaton TeV neutrino telescopes (IceCube and Cubic Kilometer) seek to open high-energy neutrino astronomy, still an elusive goal. (Amanda, IceCube, and UNO, as well as Minos, Icarus and other large neutrino facilities using non-Cherenkov technologies, are treated in other contributions to this volume.)

  3. Characteristics of Cherenkov radiation in naturally occurring ice

    NASA Astrophysics Data System (ADS)

    Mikkelsen, R. E.; Poulsen, T.; Uggerhøj, U. I.; Klein, S. R.

    2016-03-01

    We revisit the theory of Cherenkov radiation in uniaxial crystals. Historically, a number of flawed attempts have been made at explaining this radiation phenomenon, and a consistent error-free description is nowhere available. We apply our calculation to a large modern day telescope—IceCube. Located in Antarctica, this detector makes use of the naturally occurring ice as a medium to generate Cherenkov radiation. However, due to the high pressure at the depth of the detector site, large volumes of hexagonal ice crystals are formed. We calculate how this affects the Cherenkov radiation yield and angular dependence. We conclude that the effect is small, at most about a percent, and would only be relevant in future high-precision instruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For radio-Cherenkov experiments which use the presence of a clear Cherenkov cone to determine the arrival direction, any variation in emission angle will directly and linearly translate into a change in apparent neutrino direction. In closing, we also describe a simple experiment to test this formalism and calculate the impact of anisotropy on light yields from lead tungstate crystals as used, for example, in the CMS calorimeter at the CERN LHC.

  4. A module of silicon photo-multipliers for detection of Cherenkov radiation

    NASA Astrophysics Data System (ADS)

    Korpar, Samo; Chagani, Hassan; Dolenec, Rok; Križan, Peter; Pestotnik, Rok; Stanovnik, Aleš

    2010-02-01

    A module, consisting of 64 (=8×8) Hamamatsu MPPC S10362-11-100P silicon photomultipliers, has been constructed and tested as a position sensitive detector of Cherenkov photons. In order to increase the efficiency, i.e. the effective surface over which Cherenkov light is collected, we have manufactured and tested suitable light guides. In addition to the increase in efficiency, it is shown that such light guides considerably improve the signal-to-noise ratio. The results of our measurements indicate that the performance of such a Cherenkov counter with aerogel radiator could meet the requirements of particle identification at the foreseen upgraded Belle detector.

  5. Measurement of the atmospheric muon flux with the NEMO Phase-1 detector

    NASA Astrophysics Data System (ADS)

    Aiello, S.; Ameli, F.; Amore, I.; Anghinolfi, M.; Anzalone, A.; Barbarino, G.; Battaglieri, M.; Bazzotti, M.; Bersani, A.; Beverini, N.; Biagi, S.; Bonori, M.; Bouhadef, B.; Brunoldi, M.; Cacopardo, G.; Capone, A.; Caponetto, L.; Carminati, G.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coniglione, R.; Cordelli, M.; Costa, M.; D'Amico, A.; De Bonis, G.; De Marzo, C.; De Rosa, G.; De Ruvo, G.; De Vita, R.; Distefano, C.; Falchini, E.; Flaminio, V.; Fratini, K.; Gabrielli, A.; Galatà, S.; Gandolfi, E.; Giacomelli, G.; Giorgi, F.; Giovanetti, G.; Grimaldi, A.; Habel, R.; Imbesi, M.; Kulikovsky, V.; Lattuada, D.; Leonora, E.; Lonardo, A.; Lo Presti, D.; Lucarelli, F.; Marinelli, A.; Margiotta, A.; Martini, A.; Masullo, R.; Migneco, E.; Minutoli, S.; Morganti, M.; Musico, P.; Musumeci, M.; Nicolau, C. A.; Orlando, A.; Osipenko, M.; Papaleo, R.; Pappalardo, V.; Piattelli, P.; Piombo, D.; Raia, G.; Randazzo, N.; Reito, S.; Ricco, G.; Riccobene, G.; Ripani, M.; Rovelli, A.; Ruppi, M.; Russo, G. V.; Russo, S.; Sapienza, P.; Sciliberto, D.; Sedita, M.; Shirokov, E.; Simeone, F.; Sipala, V.; Spurio, M.; Taiuti, M.; Trasatti, L.; Urso, S.; Vecchi, M.; Vicini, P.; Wischnewski, R.

    2010-05-01

    The NEMO Collaboration installed and operated an underwater detector including prototypes of the critical elements of a possible underwater km 3 neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box. The detector was developed to test some of the main systems of the km 3 detector, including the data transmission, the power distribution, the timing calibration and the acoustic positioning systems as well as to verify the capabilities of a single tridimensional detection structure to reconstruct muon tracks. We present results of the analysis of the data collected with the NEMO Mini-Tower. The position of photomultiplier tubes (PMTs) is determined through the acoustic position system. Signals detected with PMTs are used to reconstruct the tracks of atmospheric muons. The angular distribution of atmospheric muons was measured and results compared to Monte Carlo simulations.

  6. The High Altitude Water Cherenkov (HAWC) Observatory

    NASA Astrophysics Data System (ADS)

    Springer, Wayne

    2014-06-01

    The High Altitude Water Cherenkov (HAWC) observatory is a continuously operated, wide field of view detector based upon a water Cherenkov technology developed by the Milagro experiment. HAWC observes, at an elevation of 4100 m on Sierra Negra Mountain in Mexico, extensive air showers initiated by gamma and cosmic rays. The completed detector will consist of 300 closely spaced water tanks each instrumented with four photomultiplier tubes that provide timing and charge information used to reconstruct energy and arrival direction. HAWC has been optimized to observe transient and steady emission from point as well as diffuse sources of gamma rays in the energy range from several hundred GeV to several hundred TeV. Studies in solar physics as well as the properties of cosmic rays will also be performed. HAWC has been making observations at various stages of deployment since completion of 10% of the array in summer 2012. A discussion of the detector design, science capabilities, current construction/commissioning status, and first results will be presented...

  7. Computationally robust and noise resistant numerical detector for the detection of atmospheric infrasound.

    PubMed

    Lee, Dong-Chang; Olson, John V; Szuberla, Curt A L

    2013-07-01

    This work reports on a performance study of two numerical detectors that are particularly useful for infrasound arrays operating under windy conditions. The sum of squares of variance ratios (SSVR1)-proposed for detecting signals with frequency ranging from 1 to 10 Hz-is computed by taking the ratio of the squared sum of eigenvalues to the square of largest eigenvalue of the covariance matrix of the power spectrum. For signals with lower frequency between 0.015 and 0.1 Hz, SSVR2 is developed to reduce the detector's sensitivity to noise. The detectors' performances are graphically compared against the current method, the mean of cross correlation maxima (MCCM), using the receiver operating characteristics curves and three types of atmospheric infrasound, corrupted by Gaussian and Pink noise. The MCCM and SSVR2 detectors were also used to detect microbaroms from the 24 h-long infrasound data. It was found that the two detectors outperform the MCCM detector in both sensitivity and computational efficiency. For mine blasts corrupted by Pink noise (signal-to-noise ratio = -7 dB), the MCCM and SSVR1 detectors yield 62 and 88 % true positives when accepting 20% false positives. For an eight-sensor array, the speed gain is approximately eleven-fold for a 50 s long signal. PMID:23862892

  8. High-Energy Astrophysics with the High Altitude Water Cherenkov (HAWC) Observatory

    NASA Astrophysics Data System (ADS)

    Pretz, John; HAWC Collaboration

    2013-04-01

    The High Altitude Water Cherenkov (HAWC) observatory, under construction at Sierra Negra in the state of Puebla, Mexico, consists of a 22500 square meter area of water Cherenkov detectors: water tanks instrumented with light-sensitive photomultiplier tubes. The experiment is used to detect energetic secondary particles reaching the ground when a 50 GeV to 100 TeV cosmic ray or gamma ray interacts in the atmosphere above the experiment. By timing the arrival of particles on the ground, the direction of the original primary particle may be resolved with an error of between 1.0 (50 GeV) and 0.1 (10 TeV) degrees. Gamma-ray primaries may be distinguished from cosmic ray background by identifying the penetrating particles characteristic of a hadronic particle shower. The instrument is 10% complete and is performing as expected, with 30% of the channels anticipated by the summer of 2013. HAWC will complement existing Imaging Atmospheric Cherenkov Telescopes and space-based gamma-ray telescopes with its extreme high-energy sensitivity and its large field-of-view. The observatory will be used to study particle acceleration in Pulsar Wind Nebulae, Supernova Remnants, Active Galactic Nuclei and Gamma-ray Bursts. Additionally, the instrument can be used to probe dark matter annihilation in halo and sub-halos of the galaxy. We will present the sensitivity of the HAWC instrument in the context of the main science objectives. We will also present the status of the deployment including first data from the instrument and prospects for the future.

  9. Bokeh mirror alignment for Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Ahnen, M. L.; Baack, D.; Balbo, M.; Bergmann, M.; Biland, A.; Blank, M.; Bretz, T.; Bruegge, K. A.; Buss, J.; Domke, M.; Dorner, D.; Einecke, S.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Lustermann, W.; Mannheim, K.; Mueller, S. A.; Neise, D.; Neronov, A.; Noethe, M.; Overkemping, A.-K.; Paravac, A.; Pauss, F.; Rhode, W.; Shukla, A.; Temme, F.; Thaele, J.; Toscano, S.; Vogler, P.; Walter, R.; Wilbert, A.

    2016-09-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with large apertures and high image intensities to map the faint Cherenkov light emitted from cosmic ray air showers onto their image sensors. Segmented reflectors fulfill these needs, and composed from mass production mirror facets they are inexpensive and lightweight. However, as the overall image is a superposition of the individual facet images, alignment remains a challenge. Here we present a simple, yet extendable method, to align a segmented reflector using its Bokeh. Bokeh alig nment does not need a star or good weather nights but can be done even during daytime. Bokeh alignment optimizes the facet orientations by comparing the segmented reflectors Bokeh to a predefined template. The optimal Bokeh template is highly constricted by the reflector's aperture and is easy accessible. The Bokeh is observed using the out of focus image of a near by point like light source in a distance of about 10 focal lengths. We introduce Bokeh alignment on segmented reflectors and demonstrate it on the First Geiger-mode Avalanche Cherenkov Telescope (FACT) on La Palma, Spain.

  10. Separation of scintillation and Cherenkov lights in linear alkyl benzene

    NASA Astrophysics Data System (ADS)

    Li, Mohan; Guo, Ziyi; Yeh, Minfang; Wang, Zhe; Chen, Shaomin

    2016-09-01

    To separate scintillation and Cherenkov lights in water-based liquid scintillator detectors is a desired feature for future neutrino and proton decay experiments. Linear alkyl benzene (LAB) is one important ingredient of a water-based liquid scintillator currently under development. In this paper we report on the separation of scintillation and Cherenkov lights observed in an LAB sample. The rise and decay times of the scintillation light are measured to be (7.7 ± 3.0) ns and (36.6 ± 2.4) ns , respectively, while the full width [-3σ, 3σ] of the Cherenkov light is 12 ns and is dominated by the time resolution of the photomultiplier tubes. The scintillation light yield was measured to be (1.01 ± 0.12) ×103 photons / MeV .

  11. Detection of tau neutrinos by imaging air Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Góra, D.; Bernardini, E.

    2016-09-01

    This paper investigates the potential to detect tau neutrinos in the energy range of 1-1000 PeV searching for very inclined showers with imaging Cherenkov telescopes. A neutrino induced tau lepton escaping from the Earth may decay and initiate an air shower which can be detected by a fluorescence or Cherenkov telescope. We present here a study of the detection potential of Earth-skimming neutrinos taking into account neutrino interactions in the Earth crust, local matter distributions at various detector sites, the development of tau-induced showers in air and the detection of Cherenkov photons with IACTs. We analyzed simulated shower images on the camera focal plane and implemented generic reconstruction chains based on Hillas parameters. We find that present IACTs can distinguish air showers induced by tau neutrinos from the background of hadronic showers in the PeV-EeV energy range. We present the neutrino trigger efficiency obtained for a few configurations being considered for the next-generation Cherenkov telescopes, i.e. the Cherenkov Telescope Array. Finally, for a few representative neutrino spectra expected from astrophysical sources, we compare the expected event rates at running IACTs to what is expected for the dedicated IceCube neutrino telescope.

  12. Desarrollo de un detector de rayos cósmicos de la colaboración LAGO en Buenos Aires - Aplicaciones en meteorología espacial

    NASA Astrophysics Data System (ADS)

    Coppola, M.; Bezzecchi, F.; Gulisano, A. M.; Masías-Meza, J. J.; Areso, O.; Ramelli, M.; Dasso, S.; LAGO Collaboration

    2016-08-01

    The study of low energy cosmic particles allows to analyze several aspects of major interest for space weather. Ground detectors permit to observe secundary particles produced during the cascades developed in the atmosphere. The characterization of a prototype for a water Cherenkov radiation particles detector, in the frame of the LAGO collaboration (Latin American Giant Observatory), is presented in this work. The collaboration plans to install this detector at the LAGO antarctic site. The developed acquisition system and the method used to make the energy callibration of the detector are detailed here, as also corrections for atmospheric effects.

  13. Mechanistic study and optimization of a hydrogen atmosphere flame ionization detector

    SciTech Connect

    Lillie, C.H.

    1985-01-01

    A residual gas analyzer was modified to study ions produced by flames similar to those used in the organometallic and organosilicon selective hydrogen atmosphere flame ionization detectors, HAFID and HAFID-Si, respectively. Flame ions traveled from 1 to 7 cm at atmospheric pressure prior to entering the vacuum chamber. The ions were then extracted and focused using an Einzel lens system into a quadrupole mass spectrometer. The mass spectrometry system was calibrated using the ions produced by a radioactive Ni-63 foil which had nitrogen gas blown over it. Optimization of the system was accomplished by varying parameters while the Ni-63 foil was the ionizing source and then with a hydrogen in air diffusion flame. The mass spectrum from a flame similar in composition to that used in the gas chromatographic flame ionization detector was compared to literature spectra to validate the results. Characterization studies of the HAFID indicated a linear range of two orders of magnitude for organics with a minimum detectable amount of 500 ng for tetradecane. An equal per carbon response pattern similar to that observed in the FID was observed with the HAFID for a homologous n-alkane series. A new detector design that allows the collector to jet tip height to be varied while the detector flame is burning was utilized in the simplex optimization of the detector. A computer program that utilizes variable sized steps in the simplex was developed to determine the next set of conditions to be tested and to determine when the optimum had been reached. A mechanism was developed to account for the selective response of the organometallic and organosilicon selective detectors. The mechanisms were based on the results of the mass spectrometric studies, characterization studies and thermodynamic data obtained from the literature.

  14. Measurement of the atmospheric muon charge ratio using the MINOS near detector

    SciTech Connect

    De Jong, J.K.; /IIT, Chicago

    2007-07-01

    The magnetized MINOS near detector has been collecting charge-separated atmospheric muon events since January 2005. To reduce the systematics due to muon acceptance equal periods of forward and reverse magnetic field data were combined. This has allowed an accurate measurement of the muon charge ratio to be performed with 8.52 days of data. We report a charge ratio of 1.288{+-}0.004(stat.){+-}0.025(syst.) at a mean surface energy of 110 GeV.

  15. The integrated cryogenic system for the atmospheric vertical interferometric detector on FY-4 satellite

    NASA Astrophysics Data System (ADS)

    Wu, Yinong; Liu, EnGuang; Jiang, Zhenhua; Yang, Baoyu; Mu, Yongbin

    2016-05-01

    The cryogenic system for the atmospheric vertical interferometric detector on FY-4 satellite includes a Stirling cryocooler, a radiant cooler, a cryogenic heat pipe and some flexible thermal links as well. These cryogenic elements were integrated together in order to decrease the background radiation and maximize the sensitivity with high efficiency and high reliability. This paper summarizes the cryogenic integration design, technical challenges, and the results of thermal and performance testing.

  16. Effects of atmospheric parameters on radon measurements using alpha-track detectors

    SciTech Connect

    Zhao, C.; Zhuo, W. Fan, D.; Yi, Y.; Chen, B.

    2014-02-15

    The calibration factors of alpha-track radon detectors (ATDs) are essential for accurate determination of indoor radon concentrations. In this paper, the effects of atmospheric parameters on the calibration factors were theoretically studied and partially testified. Based on the atmospheric thermodynamics theory and detection characteristics of the allyl diglycol carbonate (CR-39), the calibration factors for 5 types of ATDs were calculated through Monte Carlo simulations under different atmospheric conditions. Simulation results showed that the calibration factor increased by up to 31% for the ATDs with a decrease of air pressure by 35.5 kPa (equivalent to an altitude increase of 3500 m), and it also increased by up to 12% with a temperature increase from 5 °C to 35 °C, but it was hardly affected by the relative humidity unless the water-vapor condensation occurs inside the detectors. Furthermore, it was also found that the effects on calibration factors also depended on the dimensions of ATDs. It indicated that variations of the calibration factor with air pressure and temperature should be considered for an accurate radon measurement with a large dimensional ATD, and water-vapor condensation inside the detector should be avoided in field measurements.

  17. Effects of atmospheric parameters on radon measurements using alpha-track detectors

    NASA Astrophysics Data System (ADS)

    Zhao, C.; Zhuo, W.; Fan, D.; Yi, Y.; Chen, B.

    2014-02-01

    The calibration factors of alpha-track radon detectors (ATDs) are essential for accurate determination of indoor radon concentrations. In this paper, the effects of atmospheric parameters on the calibration factors were theoretically studied and partially testified. Based on the atmospheric thermodynamics theory and detection characteristics of the allyl diglycol carbonate (CR-39), the calibration factors for 5 types of ATDs were calculated through Monte Carlo simulations under different atmospheric conditions. Simulation results showed that the calibration factor increased by up to 31% for the ATDs with a decrease of air pressure by 35.5 kPa (equivalent to an altitude increase of 3500 m), and it also increased by up to 12% with a temperature increase from 5 °C to 35 °C, but it was hardly affected by the relative humidity unless the water-vapor condensation occurs inside the detectors. Furthermore, it was also found that the effects on calibration factors also depended on the dimensions of ATDs. It indicated that variations of the calibration factor with air pressure and temperature should be considered for an accurate radon measurement with a large dimensional ATD, and water-vapor condensation inside the detector should be avoided in field measurements.

  18. Effects of atmospheric parameters on radon measurements using alpha-track detectors.

    PubMed

    Zhao, C; Zhuo, W; Fan, D; Yi, Y; Chen, B

    2014-02-01

    The calibration factors of alpha-track radon detectors (ATDs) are essential for accurate determination of indoor radon concentrations. In this paper, the effects of atmospheric parameters on the calibration factors were theoretically studied and partially testified. Based on the atmospheric thermodynamics theory and detection characteristics of the allyl diglycol carbonate (CR-39), the calibration factors for 5 types of ATDs were calculated through Monte Carlo simulations under different atmospheric conditions. Simulation results showed that the calibration factor increased by up to 31% for the ATDs with a decrease of air pressure by 35.5 kPa (equivalent to an altitude increase of 3500 m), and it also increased by up to 12% with a temperature increase from 5 °C to 35 °C, but it was hardly affected by the relative humidity unless the water-vapor condensation occurs inside the detectors. Furthermore, it was also found that the effects on calibration factors also depended on the dimensions of ATDs. It indicated that variations of the calibration factor with air pressure and temperature should be considered for an accurate radon measurement with a large dimensional ATD, and water-vapor condensation inside the detector should be avoided in field measurements. PMID:24593337

  19. Cherenkov infrared laser

    SciTech Connect

    Johnson, B.; Walsh, J.

    1985-01-01

    Successful production of microwave radiation by Cherenkov masers has prompted an investigation into their feasibility for submillimeter and far-infrared wavelength generation. A theoretical examination of output parameters such as frequency and small signal gain was conducted for an easily fabricated resonator geometry. The resonator consists of two parallel plates, each with a thin (0.5 to 3 ..mu..m) dielectric coating, separated by 2 mm. This waveguide will support TM modes which are coupled to a relativistic electron beam propagating between the plates. While the interaction of the electrons with the dielectric causes spontaneous Cherenkov emission, the difference between the beam velocity and the phase velocity of the mode causes a bunching of the electrons which is responsible for further stimulated emission. The frequency of the generated radiation is determined by the dispersion relation of the waveguide mode. Gain is calculated assuming the effects of space-charge modes are negligible i.e., operation is in the Compton regime. Results indicate that such a double-slab resonator will provide detectable levels of infrared radiation from a mildly relativistic (3-10 MeV) electron beam. The theoretical analysis is undertaken in preparation for a series of experiments to be conducted at the ENEA facility in Frascati, Italy where a 5 MeV microtron accelerator will be used to produce radiation in the 10- to 100 ..mu..m range. A suitable choice for the dielectric material would be polyethylene, both because of its low dielectric constant (2.2) and its relatively low loss in the infrared. A detailed discussion of the design choices will be presented.

  20. The possibilities of Cherenkov telescopes to perform cosmic-ray muon imaging of volcanoes

    NASA Astrophysics Data System (ADS)

    Carbone, Daniele; Catalano, Osvaldo; Cusumano, Giancarlo; Del Santo, Melania; Maccarone, Maria Concetta; Mineo, Teresa; Pareschi, Giovanni; Vercellone, Stefano; Zuccarello, Luciano

    2016-04-01

    Volcanic activity is regulated by the interaction of gas-liquid flow with conduit geometry. Hence, the quantitative understanding of the inner shallow structure of a volcano is mandatory to forecast the occurrence of dangerous stages of activity and mitigate volcanic hazards. Among the techniques used to investigate the underground structure of a volcano, muon imaging offers some advantages, as it provides a fine spatial resolution, and does not require neither spatially dense measurements in active zones, nor the implementation of cost demanding energizing systems, as when electric or active seismic sources are utilized. The principle of muon radiography is essentially the same as X-ray radiography: muons are more attenuated by higher density parts inside the target and thus information about its inner structure are obtained from the differential muon absorption. Up-to-date, muon imaging of volcanic structures has been mainly accomplished with detectors that employ planes of scintillator strips. These telescopes are exposed to different types of background noise (accidental coincidence of vertical shower particles, horizontal high-energy electrons, flux of upward going particles), whose amplitude is high relative to the tiny flux of interest. An alternative technique is based on the detection of the Cherenkov light produced by muons. The latter can be imaged as an annular pattern that contains the information needed to reconstruct both direction and energy of the particle. Cherenkov telescopes have never been utilized to perform muon imaging of volcanoes. Nonetheless, thanks to intrinsic features, they offer the possibility to detect the through-target muon flux with negligible levels of background noise. Under some circumstances, they would also provide a better spatial resolution and acceptance than scintillator-based telescopes. Furthermore, contrarily to the latter systems, Cherenkov detectors allow in-situ measurements of the open-sky energy spectrum of

  1. Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array

    SciTech Connect

    Ahrens, J.; Andres, E.; Bai, X.; Barouch, G.; Barwick, S.W.; Bay, R.C.; Becka, T.; Becker, K.-H.; Bertrand, D.; Binon, F.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Bouhali, O.; Boyce, M.M.; Carius, S.; Chen, A.; Chirkin, D.; Conrad, J.; Cooley, J.; Costa, C.G.S.; Cowen, D.F.; Dalberg, E.; De Clercq, C.; DeYoung, T.; Desiati, P.; Dewulf, J.-P.; Doksus, P.; Edsjo, J.; Ekstrom, P.; Feser, T.; Frere, J.-M.; Gaisser, T.K.; Gaug, M.; Goldschmidt, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Hardtke, R.; Hauschildt, T.; Hellwig, M.; Heukenkamp, H.; Hill, G.C.; Hulth, P.O.; Hundertmark, S.; Jacobsen, J.; Karle, A.; Kim, J.; Koci, B.; Kopke, L.; Kowalski, M.; Lamoureux, J.I.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Loaiza, P.; Lowder, D.M.; Madsen, J.; Marciniewski, P.; Matis, H.S.; McParland, C.P.; Miller, T.C.; Minaeva, Y.; Miocinovic, P.; Mock, P.C.; Morse, R.; Neunhoffer, T.; Niessen, P.; Nygren, D.R.; Ogelman, H.; Olbrechts, Ph.; Perez de los Heros, C.; Pohl, A.C.; Porrata, R.; Price, P.B.; Przybylski, G.T.; Rawlins, K.; Reed, C.; Rhode, W.; Ribordy, M.; Richter, S.; Rodriguez Martino, J.; Romenesko, P.; Ross, D.; Sander, H.-G.; Schmidt, T.; Schneider, D.; Schwarz, R.; Silvestri, A.; Solarz, M.; Spiczak, G.M.; Spiering, C.; Starinsky, N.; Steele, D.; Steffen, P.; Stokstad, R.G.; Streicher, O.; Sudhoff, P.; Sulanke, K.-H.; Taboada, I.; Thollander, L.; Thon, T.; Tilav, S.; Vander Donckt, M.; Walck, C.; Weinheimer, C.; Wiebusch, C.H.; Wiedeman, C.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S.

    2002-05-07

    The Antarctic Muon and Neutrino Detector Array (AMANDA) began collecting data with ten strings in 1997. Results from the first year of operation are presented. Neutrinos coming through the Earth from the Northern Hemisphere are identified by secondary muons moving upward through the array. Cosmic rays in the atmosphere generate a background of downward moving muons, which are about 10{sup 6} times more abundant than the upward moving muons. Over 130 days of exposure, we observed a total of about 300 neutrino events. In the same period, a background of 1.05 x 10{sup 9} cosmic ray muon events was recorded. The observed neutrino flux is consistent with atmospheric neutrino predictions. Monte Carlo simulations indicate that 90 percent of these events lie in the energy range 66 GeV to 3.4 TeV. The observation of atmospheric neutrinos consistent with expectations establishes AMANDA-B10 as a working neutrino telescope.

  2. A study of atmospheric neutrino oscillation using the icecube deepcore detector

    NASA Astrophysics Data System (ADS)

    Gladstone, Laura

    The IceCube detector at the South Pole is a cubic-kilometer-scale neutrino detector designed to observe TeV-range charged particle secondaries from neutrino interactions, and thus do neutrino astronomy. As a main background to the search for astrophysical point sources of neutrinos, IceCube also observes muons and neutrinos from the atmospheric interactions of cosmic rays. By observing a spectrum of atmospheric neutrinos and comparing it to independent predictions of atmospheric fluxes with and without oscillations, IceCube can test various values of oscillation parameters. Neutrino oscillations have been observed experimentally for several decades; IceCube is the first experiment to extend this measurement to the 10-20 GeV energy range. An initial analysis has established that IceCube can see oscillations using the 79-string detector configuration ("IC79"), which was the first year of data that included the DeepCore detector. As a follow-up, this analysis uses a less restrictive event selection and thus a higher total event count, around 3,000 for one year of data. The fit is a Poisson likelihood fit of a two-dimensional rate histogram, using both oscillated length and observed energy. The arrival zenith angle of the muon is used as a proxy for oscillation length. The error contours are dominated by systematic effects more than by statistical limitations of the data. Major systematics include uncertainties in the atmospheric neutrino flux at high energies and uncertainties in the distribution of the cosmic ray muon background. This analysis was designed to produce limits on the mixing angle θ 23 that are competitive with other current experiments, although this is still uncertain as error analysis work is ongoing. Future work will further refine the event selection and systematic error analysis; the statistical methods and software used here are expected to become the IceCube oscillations standard. This thesis also includes background information about the

  3. Microsecond Time Resolution Optical Photometry using a H.E.S.S. Cherenkov Telescope

    SciTech Connect

    Deil, Christoph; Domainko, Wilfried; Hermann, German

    2008-02-22

    We have constructed an optical photometer with microsecond time resolution, which is currently being operated on one of the H.E.S.S. telescopes. H.E.S.S. is an array of four Cherenkov telescopes, each with a 107 m{sup 2} mirror, located in the Khomas highland in Namibia. In its normal mode of operation H.E.S.S. observes Cherenkov light from air showers generated by very high energy gamma-rays in the upper atmosphere. Our detector consists of seven photomultipliers, one in the center to record the lightcurve from the target and six concentric photomultipliers as a veto system to reject disturbing signals e.g. from meteorites or lightning at the horizon. The data acquisition system has been designed to continuously record the signals with zero deadtime. The Crab pulsar has been observed to verify the performance of the instrument and the GPS timing system. Compact galactic targets were observed to search for flares on timescales of a few microseconds to {approx}100 ms. The design and sensitivity of the instrument as well as the data analysis method are presented.

  4. A method of observing cherenkov light from extensive air shower at Yakutsk EAS array

    NASA Astrophysics Data System (ADS)

    Timofeev, Lev; Anatoly, Ivanov

    2016-07-01

    Proposed a new method for measuring the cherenkov light from the extensive air shower (EAS) of cosmic rays (CR), which allows to determine not only the primary particle energy and angle of arrival, but also the parameters of the shower in the atmosphere - the maximum depth and "age". For measurements Cherenkov light produced by EAS is proposed to use a ground network of wide-angle telescopes which are separated from each other by a distance 100-300 m depending on the total number of telescopes operating in the coincidence signals, acting autonomously, or includes a detector of the charged components, radio waves, etc. as part of EAS. In a results such array could developed, energy measurement and CR angle of arrival data on the depth of the maximum and the associated mass of the primary particle generating by EAS. This is particularly important in the study of galactic cosmic ray in E> 10^14 eV, where currently there are no direct measurements of the maximum depth of the EAS.

  5. Fast, Large-Area, Wide-Bandgap UV Photodetector for Cherenkov Light Detection

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Wrbanek, Susan Y.

    2013-01-01

    Due to limited resources available for power and space for payloads, miniaturizing and integrating instrumentation is a high priority for addressing the challenges of manned and unmanned deep space missions to high Earth orbit (HEO), near Earth objects (NEOs), Lunar and Martian orbits and surfaces, and outer planetary systems, as well as improvements to high-altitude aircraft safety. New, robust, and compact detectors allow future instrumentation packages more options in satisfying specific mission goals. A solid-state ultraviolet (UV) detector was developed with a theoretical fast response time and large detection area intended for application to Cherenkov detectors. The detector is based on the wide-bandgap semiconductor zinc oxide (ZnO), which in a bridge circuit can detect small, fast pulses of UV light like those required for Cherenkov detectors. The goal is to replace the role of photomultiplier tubes in Cherenkov detectors with these solid-state devices, saving on size, weight, and required power. For improving detection geometry, a spherical detector to measure high atomic number and energy (HZE) ions from any direction has been patented as part of a larger space radiation detector system. The detector will require the development of solid-state UV photodetectors fast enough (2 ns response time or better) to detect the shockwave of Cherenkov light emitted as the ions pass through a quartz, sapphire, or acrylic ball. The detector must be small enough to fit in the detector system structure, but have an active area large enough to capture enough Cherenkov light from the sphere. The detector is fabricated on bulk single-crystal undoped ZnO. Inter - digitated finger electrodes and contact pads are patterned via photolithography, and formed by sputtered metal of silver, platinum, or other high-conductivity metal.

  6. Atmospheric measurements by Medipix-2 and Timepix Ionizing Radiation Imaging Detectors on BEXUS stratospheric balloon campaigns

    NASA Astrophysics Data System (ADS)

    Urbar, Jaroslav; Scheirich, Jan; Jakubek, Jan

    2010-05-01

    Results of the first two experiments using semiconductor pixel detectors of the Medipix family for cosmic ray imaging in the stratospheric environment are presented. The original detecting device was based on the hybrid pixel detectors of Medipix-2 and Timepix developed at CERN with USB interface developed at Institute of Experimental and Applied Physics of Czech Technical University in Prague. The detectors were used in tracking mode allowing them to operate as an "active nuclear emulsion". The actual flight time of BEXUS7 with Medipix-2 on 8th October 2008 was over 4 hours, with 2 hours at stable floating altitude of 26km. BEXUS9 measurements of similar duration by Timepix, Medipix-2 and ST-6 Geiger telescope instruments took place in arctic atmosphere below 24km altitude on 11th October 2009. This balloon platform is quite ideal for such in-situ measurements. Not only because of the high altitudes reached, but also due to its slow ascent velocity for statistically relevant sampling of the ambient environment for improving cosmic ray induced ionisation rate model inputs. The flight opportunity for BEXUS student projects was provided by Education department of the European Space Agency (ESA) and Eurolaunch - Collaboration of Swedish National Space Board (SNSB) and German Space Agency (DLR). The scientific goal was to check energetic particle type altitudinal dependencies, also testing proper detector calibration by detecting fluxes of ionizing radiation, while evaluating instrumentation endurance and performance.

  7. The High-Altitude Water Cherenkov Observatory

    NASA Astrophysics Data System (ADS)

    Mostafá, Miguel A.

    2014-10-01

    The High-Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV γ-ray experiment under construction at 4,100 m a.s.l. in Mexico. The HAWC observatory will have an order of magnitude better sensitivity, angular resolution, and background rejection than its predecessor, the Milagro experiment. The improved performance will allow us to detect both the transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV γ-ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from γ-ray bursts above 50 GeV. The HAWC observatory will consist of an array of 300 water Cherenkov detectors (WCDs), each with four photomultiplier tubes. This array is currently under construction on the flanks of the Sierra Negra volcano near the city of Puebla, Mexico. The first 30 WCDs (forming an array approximately the size of Milagro) were deployed in Summer 2012, and 100 WCDs will be taking data by May, 2013. We present in this paper the motivation for constructing the HAWC observatory, the status of the deployment, and the first results from the constantly growing array.

  8. 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.

  9. Stimulated Cherenkov emission in gas dynamics

    SciTech Connect

    Kuzelev, M. V. Rukhadze, A. A.

    2008-11-15

    A linear theory is developed for stimulated Cherenkov emission from planar and cylindrical gas flows in gaseous environments. An analogy is demonstrated between Cherenkov emission in gas dynamics and stimulated Cherenkov electromagnetic emission from a charged particle beam in a medium.

  10. Development of a diagnostic technique based on Cherenkov effect for measurements of fast electrons in fusion devices

    SciTech Connect

    Plyusnin, V. V.; Duarte, P.; Fernandes, H.; Silva, C.

    2012-08-15

    A diagnostic technique based on the Cherenkov effect is proposed for detection and characterization of fast (super-thermal and runaway) electrons in fusion devices. The detectors of Cherenkov radiation have been specially designed for measurements in the ISTTOK tokamak. Properties of several materials have been studied to determine the most appropriate one to be used as a radiator of Cherenkov emission in the detector. This technique has enabled the detection of energetic electrons (70 keV and higher) and the determination of their spatial and temporal variations in the ISTTOK discharges. Measurement of hard x-ray emission has also been carried out in experiments for validation of the measuring capabilities of the Cherenkov-type detector and a high correlation was found between the data of both diagnostics. A reasonable agreement was found between experimental data and the results of numerical modeling of the runaway electron generation in ISTTOK.

  11. Design optimization of the proximity focusing RICH with dual aerogel radiator using a maximum-likelihood analysis of Cherenkov rings

    NASA Astrophysics Data System (ADS)

    Pestotnik, R.; Križan, P.; Korpar, S.; Iijima, T.

    2008-09-01

    The use of a sequence of aerogel radiators with different refractive indices in a proximity focusing Cherenkov ring imaging detector has been shown to improve the resolution of the Cherenkov angle. In order to obtain further information on the capabilities of such a detector, a maximum-likelihood analysis has been performed on simulated data, with the simulation being appropriate for the upgraded Belle detector. The results show that by using a sequence of two aerogel layers with different refractive indices, the K/π separation efficiency is improved in the kinematic region above 3 GeV/ c. In the low momentum region, the focusing configuration (with n1 and n2 chosen such that the Cherenkov rings from different aerogel layers at 4 GeV/ c overlap) shows a better performance than the defocusing one (where the two Cherenkov rings are well separated).

  12. Results on the Performance of a Broad Band Focussing Cherenkov Counter

    DOE R&D Accomplishments Database

    Cester, R.; Fitch, V. L.; Montag, A.; Sherman, S.; Webb, R. C.; Witherell, M. S.

    1980-01-01

    The field of ring imaging (broad band differential) Cherenkov detectors has become a very active area of interest in detector development at several high energy physics laboratories. Our group has previously reported on a method of Cherenkov ring imaging for a counter with large momentum and angular acceptance using standard photo multipliers. Recently, we have applied this technique to the design of a set of Cherenkov counters for use in a particle search experiment at Fermi National Accelerator Laboratory (FNAL). This new detector operates over the range 0.998 < ..beta.. < 1.000 in velocity with a delta..beta.. approx. 2 x 10{sup -4}. The acceptance in angle is +- 14 mrad in the horizontal and +- 28 mrad in the vertical. We report here on the performance of this counter.

  13. Josephson-vortex Cherenkov radiation

    SciTech Connect

    Mints, R.G.; Snapiro, I.B.

    1995-10-01

    We predict the Josephson-vortex Cherenkov radiation of an electromagnetic wave. We treat a long one-dimensional Josephson junction. We consider the wavelength of the radiated electromagnetic wave to be much less than the Josephson penetration depth. We use for calculations the nonlocal Josephson electrodynamics. We find the expression for the radiated power and for the radiation friction force acting on a Josephson vortex and arising due to the Cherenkov radiation. We calculate the relation between the density of the bias current and the Josephson vortex velocity.

  14. Cherenkov radiation oscillator without reflectors

    SciTech Connect

    Li, D.; Wang, Y.; Wei, Y.; Yang, Z.; Hangyo, M.; Miyamoto, S.

    2014-05-12

    This Letter presents a Cherenkov radiation oscillator with an electron beam travelling over a finitely thick plate made of negative-index materials. In such a scheme, the external reflectors required in the traditional Cherenkov oscillators are not necessary, since the electromagnetic energy flows backward in the negative-index materials, leading to inherent feedback. We theoretically analyzed the interaction between the electron beam and the electromagnetic wave, and worked out the growth rate and start current through numerical calculations. With the help of particle-in-cell simulation, the theoretical predictions are well demonstrated.

  15. Simulation of the ASTRI two-mirrors small-size telescope prototype for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Bigongiari, C.; Cusumano, G.; Di Pierro, F.; La Parola, V.; Stamerra, A.; Vallania, P.; ASTRI Collaboration; CTA Consortium, the

    2016-05-01

    The Cherenkov Telescope Array (CTA) is a world-wide project to build a new generation ground-based gamma-ray instrument operating in the energy range from some tens of GeV to above 100 TeV. To ensure full sky coverage CTA will consist of two arrays of Imaging Atmospheric Cherenkov Telescopes (IACTs), one in the southern hemisphere and another one in the northern hemisphere. CTA has just completed the design phase and it is entering in the pre-production one that includes the development of telescope precursor mini-arrays. ASTRI is an ongoing project, to develop and install at the southern CTA site one of such mini-arrays composed by nine dual-mirror small size telescopes equipped with an innovative camera based on silicon photomultiplier sensors. The end-to-end telescope prototype, named ASTRI SST-2M, has been recently inaugurated at the Serra La Nave observing station, on Mount Etna, Italy. ASTRI SST-2M expected performance has been carefully studied using a full Monte Carlo simulation of the shower development in the atmosphere and detector response. Simulated data have been analyzed using the traditional Hillas moment analysis to obtain the expected angular and energy resolution. Simulation results, together with the comparison with the available experimental measurements, are shown.

  16. Silica aerogel threshold Cherenkov counters for the JLab Hall A spectrometers: improvements and proposed modifications

    SciTech Connect

    Luigi Lagamba; Evaristo Cisbani; S. Colilli; R. Crateri; R. De Leo; Salvatore Frullani; Franco Garibaldi; F. Giuliani; M. Gricia; Mauro Iodice; Riccardo Iommi; A. Leone; M. Lucentini; A. Mostarda; E. Nappi; Roberto Perrino; L. Pierangeli; F. Santavenere; Guido M. Urciuoli

    2001-10-01

    Recently approved experiments at Jefferson Lab Hall A require a clean kaon identification in a large electron, pion, and proton background environment. To this end, improved performance is required of the silica aerogel threshold Cherenkov counters installed in the focal plane of the two Hall A spectrometers. In this paper we propose two strategies to improve the performance of the Cherenkov counters which presently use a hydrophilic aerogel radiator, and convey Cherenkov photons towards the photomultipliers by means of mirrors with a parabolic shape in one direction and flat in the other. The first strategy is aerogel baking. In the second strategy we propose a modification of the counter geometry by replacing the mirrors with a planar diffusing surface and by displacing in a different way the photomultipliers. Tests at CERN with a 5GeV/c multiparticle beam revealed that both the strategies are able to increase significantly the number of the detected Cherenkov photons and, therefore, the detector performance.

  17. The seasonal and global behavior of water vapor in the Mars atmosphere - Complete global results of the Viking atmospheric water detector experiment

    NASA Technical Reports Server (NTRS)

    Jakosky, B. M.; Farmer, C. B.

    1982-01-01

    A key question regarding the evolution of Mars is related to the behavior of its volatiles. The present investigation is concerned with the global and seasonal abundances of water vapor in the Mars atmosphere as mapped by the Viking Mars Atmospheric Water Detector (MAWD) instrument for almost 1-1/2 Martian years from June 1976 to April 1979. Attention is given to the implications of the observed variations for determining the relative importance of those processes which may be controlling the vapor cycle on a seasonal basis. The processes considered include buffering of the atmosphere water by a surface or subsurface reservior of ground ice, physically adsorbed water, or chemically bound water. Other processes are related to the supply of water from the residual or seasonal north polar ice cap, the redistribution of the vapor resulting from atmospheric circulation, and control of the vapor holding capacity of the atmosphere by the local atmospheric temperatures.

  18. Neutrino Detectors: Challenges and Opportunities

    SciTech Connect

    Soler, F. J. P.

    2011-10-06

    This paper covers possible detector options suitable at future neutrino facilities, such as Neutrino Factories, Super Beams and Beta Beams. The Magnetised Iron Neutrino Detector (MIND), which is the baseline detector at a Neutrino Factory, will be described and a new analysis which improves the efficiency of this detector at low energies will be shown. Other detectors covered include the Totally Active Scintillating Detectors (TASD), particularly relevant for a low energy Neutrino Factory, emulsion detectors for tau detection, liquid argon detectors and megaton scale water Cherenkov detectors. Finally the requirements of near detectors for long-baseline neutrino experiments will be demonstrated.

  19. Measurement of the charge ratio of atmospheric muons with the CMS detector

    SciTech Connect

    Khachatryan, Vardan; et al.

    2010-08-01

    We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 \\pm 0.0032(stat.) \\pm 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments.

  20. GEANT4 simulations of Cherenkov reaction history diagnostics.

    PubMed

    Rubery, M S; Horsfield, C J; Herrmann, H W; Kim, Y; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedilleo, T J; McEvoy, A; Miller, E K; Stoeffl, W; Ali, Z; Toebbe, J

    2010-10-01

    This paper compares the results from a GEANT4 simulation of the gas Cherenkov detector 1 (GCD1) with previous simulations and experimental data from the Omega laser facility. The GCD1 collects gammas emitted during a deuterium-tritium capsule implosion and converts them, through several processes, to Cherenkov light. Photon signals are recorded using subnanosecond photomultiplier tubes, producing burn reaction histories. The GEANT4 GCD1 simulation is first benchmarked against ACCEPT, an integrated tiger series code, with good agreement. The simulation is subsequently compared with data from the Omega laser facility, where experiments have been performed to measure the effects of Hohlraum materials on reaction history signals, in preparation for experiments at the National Ignition Facility. PMID:21033850

  1. GEANT4 simulations of Cherenkov reaction history diagnostics

    SciTech Connect

    Rubery, M. S.; Horsfield, C. J.; Herrmann, H. W.; Kim, Y.; Mack, J. M.; Young, C. S.; Caldwell, S. E.; Evans, S. C.; Sedilleo, T. J.; McEvoy, A.; Miller, E. K.; Stoeffl, W.; Ali, Z.

    2010-10-15

    This paper compares the results from a GEANT4 simulation of the gas Cherenkov detector 1 (GCD1) with previous simulations and experimental data from the Omega laser facility. The GCD1 collects gammas emitted during a deuterium-tritium capsule implosion and converts them, through several processes, to Cherenkov light. Photon signals are recorded using subnanosecond photomultiplier tubes, producing burn reaction histories. The GEANT4 GCD1 simulation is first benchmarked against ACCEPT, an integrated tiger series code, with good agreement. The simulation is subsequently compared with data from the Omega laser facility, where experiments have been performed to measure the effects of Hohlraum materials on reaction history signals, in preparation for experiments at the National Ignition Facility.

  2. GEANT4 simulations of Cherenkov reaction history diagnosticsa)

    NASA Astrophysics Data System (ADS)

    Rubery, M. S.; Horsfield, C. J.; Herrmann, H. W.; Kim, Y.; Mack, J. M.; Young, C. S.; Caldwell, S. E.; Evans, S. C.; Sedilleo, T. J.; McEvoy, A.; Miller, E. K.; Stoeffl, W.; Ali, Z.; Toebbe, J.

    2010-10-01

    This paper compares the results from a GEANT4 simulation of the gas Cherenkov detector 1 (GCD1) with previous simulations and experimental data from the Omega laser facility. The GCD1 collects gammas emitted during a deuterium-tritium capsule implosion and converts them, through several processes, to Cherenkov light. Photon signals are recorded using subnanosecond photomultiplier tubes, producing burn reaction histories. The GEANT4 GCD1 simulation is first benchmarked against ACCEPT, an integrated tiger series code, with good agreement. The simulation is subsequently compared with data from the Omega laser facility, where experiments have been performed to measure the effects of Hohlraum materials on reaction history signals, in preparation for experiments at the National Ignition Facility.

  3. First search for atmospheric and extraterrestrial neutrino-induced cascades with the IceCube detector

    SciTech Connect

    Abbasi, R.; Aguilar, J. A.; Andeen, K.; Baker, M.; BenZvi, S.; Berghaus, P.; Braun, J.; Chirkin, D.; Desiati, P.; Diaz-Velez, J. C.; Dumm, J. P.; Eisch, J.; Gladstone, L.; Grullon, S.; Halzen, F.; Hill, G. C.; Hoshina, K.; Jacobsen, J.; Karle, A.; Kelley, J. L.

    2011-10-01

    We report on the first search for atmospheric and for diffuse astrophysical neutrino-induced showers (cascades) in the IceCube detector using 257 days of data collected in the year 2007-2008 with 22 strings active. A total of 14 events with energies above 16 TeV remained after event selections in the diffuse analysis, with an expected total background contribution of 8.3{+-}3.6. At 90% confidence we set an upper limit of E{sup 2}{Phi}{sub 90%CL}<3.6x10{sup -7} GeV{center_dot}cm{sup -2}{center_dot}s{sup -1}{center_dot}sr{sup -1} on the diffuse flux of neutrinos of all flavors in the energy range between 24 TeV and 6.6 PeV assuming that {Phi}{proportional_to}E{sup -2} and the flavor composition of the {nu}{sub e} ratio {nu}{sub {mu}} ratio {nu}{sub {tau}} flux is 1 ratio 1 ratio 1 at the Earth. The atmospheric neutrino analysis was optimized for lower energies. A total of 12 events were observed with energies above 5 TeV. The observed number of events is consistent with the expected background, within the uncertainties.

  4. An atmospheric muon neutrino disappearance measurement with the MINOS far detector

    SciTech Connect

    Gogos, Jeremy Peter

    2007-12-01

    It is now widely accepted that the Standard Model assumption of massless neutrinos is wrong, due primarily to the observation of solar and atmospheric neutrino flavor oscillations by a small number of convincing experiments. The MINOS Far Detector, capable of observing both the outgoing lepton and associated showering products of a neutrino interaction, provides an excellent opportunity to independently search for an oscillation signature in atmospheric neutrinos. To this end, a MINOS data set from an 883 live day, 13.1 kt-yr exposure collected between July, 2003 and April, 2007 has been analyzed. 105 candidate charged current muon neutrino interactions were observed, with 120.5 ± 1.3 (statistical error only) expected in the absence of oscillation. A maximum likelihood analysis of the observed log(L/E) spectrum shows that the null oscillation hypothesis is excluded at over 96% confidence and that the best fit oscillation parameters are sin223 = 0.95 -0.32 and Δm$2\\atop{23}$ = 0.93$+3.94\\atop{ -0.44}$ x 10-3 eV2. This measurement of oscillation parameters is consistent with the best fit values from the Super-Kamiokande experiment at 68% confidence.

  5. Status and updates from the High Altitude Water Cherenkov (HAWC) Observatory

    NASA Astrophysics Data System (ADS)

    Baughman, B. M.

    2013-06-01

    The High Altitude Water Cherenkov Observatory (HAWC) is currently being deployed on the slopes of Volcan Sierra Negra, Puebla, Mexico. The HAWC observatory will consist of 300 Water Cherenkov Detectors totaling approximately 22,000 m of instrumented area. The water Cherenkov technique allows HAWC to have a nearly 100% duty cycle and large field of view, making the HAWC observatory an ideal instrument for the study of transient phenomena. With its large effective area, excellent angular and energy resolutions, and efficient gamma-hadron separation, HAWC will survey the TeV gamma ray sky, measure spectra of galactic sources from 1 TeV to beyond 100 TeV, and map galactic diffuse gamma ray emission. The science goals and performance of the HAWC observatory as well as how it will complement contemporaneous space and ground-based detectors will be presented.

  6. Angular distribution of Cherenkov radiation from relativistic heavy ions taking into account deceleration in the radiator

    SciTech Connect

    Bogdanov, O. V. Fiks, E. I.; Pivovarov, Yu. L.

    2012-09-15

    Numerical methods are used to study the dependence of the structure and the width of the angular distribution of Vavilov-Cherenkov radiation with a fixed wavelength in the vicinity of the Cherenkov cone on the radiator parameters (thickness and refractive index), as well as on the parameters of the relativistic heavy ion beam (charge and initial energy). The deceleration of relativistic heavy ions in the radiator, which decreases the velocity of ions, modifies the condition of structural interference of the waves emitted from various segments of the trajectory; as a result, a complex distribution of Vavilov-Cherenkov radiation appears. The main quantity is the stopping power of a thin layer of the radiator (average loss of the ion energy), which is calculated by the Bethe-Bloch formula and using the SRIM code package. A simple formula is obtained to estimate the angular distribution width of Cherenkov radiation (with a fixed wavelength) from relativistic heavy ions taking into account the deceleration in the radiator. The measurement of this width can provide direct information on the charge of the ion that passes through the radiator, which extends the potentialities of Cherenkov detectors. The isotopic effect (dependence of the angular distribution of Vavilov-Cherenkov radiation on the ion mass) is also considered.

  7. Design and Fabrication of Cherenkov Counters for the Detection of SNM

    SciTech Connect

    Erickson, Anna S.; Lanza, Richard; Galaitsis, Anthony; Hynes, Michael; Blackburn, Brandon; Bernstein, Adam

    2011-12-13

    The need for large-size detectors for long-range active interrogation (AI) detection of SNM has generated interest in water-based detector technologies. Water Cherenkov Detectors (WCD) were selected for this research because of their transportability, scalability, and an inherent energy threshold. The detector design and analysis was completed using the Geant4 toolkit. It was demonstrated both computationally and experimentally that it is possible to use WCD to detect and characterize gamma rays. Absolute efficiency of the detector (with no energy cuts applied) was determined to be around 30% for a {sup 60}Co source.

  8. Calibration strategies for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Gaug, Markus; Berge, David; Daniel, Michael; Doro, Michele; Förster, Andreas; Hofmann, Werner; Maccarone, Maria C.; Parsons, Dan; de los Reyes Lopez, Raquel; van Eldik, Christopher

    2014-08-01

    The Central Calibration Facilities workpackage of the Cherenkov Telescope Array (CTA) observatory for very high energy gamma ray astronomy defines the overall calibration strategy of the array, develops dedicated hardware and software for the overall array calibration and coordinates the calibration efforts of the different telescopes. The latter include LED-based light pulsers, and various methods and instruments to achieve a calibration of the overall optical throughput. On the array level, methods for the inter-telescope calibration and the absolute calibration of the entire observatory are being developed. Additionally, the atmosphere above the telescopes, used as a calorimeter, will be monitored constantly with state-of-the-art instruments to obtain a full molecular and aerosol profile up to the stratosphere. The aim is to provide a maximal uncertainty of 10% on the reconstructed energy-scale, obtained through various independent methods. Different types of LIDAR in combination with all-sky-cameras will provide the observatory with an online, intelligent scheduling system, which, if the sky is partially covered by clouds, gives preference to sources observable under good atmospheric conditions. Wide-field optical telescopes and Raman Lidars will provide online information about the height-resolved atmospheric extinction, throughout the field-of-view of the cameras, allowing for the correction of the reconstructed energy of each gamma-ray event. The aim is to maximize the duty cycle of the observatory, in terms of usable data, while reducing the dead time introduced by calibration activities to an absolute minimum.

  9. NICHE: Using Cherenkov radiation to extend Telescope Array to sub-PeV energies

    NASA Astrophysics Data System (ADS)

    Bergman, Douglas; Krizmanic, John; Tsunesada, Yoshiki; Abu-Zayyad, Tareq; Belz, John; Thomson, Gordon

    2016-03-01

    The Non-Imaging CHErenkov (NICHE) Array will measure the flux and nuclear composition evolution of cosmic rays (CRs) from below 1 PeV to 1 EeV. NICHE will be co-sited with the Telescope Array (TA) Low Energy (TALE) extension, and will observe events simultaneously with the TALE telescopes acting in imaging-Cherenkov mode. This will be the first hybrid-Cherenkov (simultaneous imaging and non-imaging Cherenkov) measurements of CRs in the Knee region of the CR energy spectrum. NICHE uses easily deployable detectors to measure the amplitude and time-spread of the air-shower Cherenkov signal to achieve an event-by-event measurement of Xmax and energy, each with excellent resolution. First generation detectors are under construction and will form an initial prototype array (j-NICHE) that will be deployed in Summer 2016. In this talk, the NICHE design, array performance, prototype development, and status will be discussed as well as NICHE's ability to measure the cosmic ray nuclear composition as a function of energy.

  10. Cherenkov and scintillation light separation on the TheiaR &D experiment

    NASA Astrophysics Data System (ADS)

    Caravaca, Javier; Land, Benjamin

    2016-03-01

    Identifying by separate the scintillation and Cherenkov light produced in a scintillation medium enables outstanding capabilities for future particle detectors, being the most relevant: allowing particle directionality information in a low energy threshold detector and improved particle identification. The TheiaR &D experiment uses an array of small and fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillation medium, based on the number of produced photoelectrons and the timing information. A charged particle ionizing a scintillation medium produces a prompt Cherenkov cone and late isotropic scintillation light, typically delayed by <1ns. The fast response of our PMTs and DAQ provides a precision well below the ns level, making possible the time separation. Furthermore, the usage of the new developed water-based liquid scintillators (WBLS) provides a medium with a tunable Cherenkov/Scintillation light yield ratio, enhancing the visibility of the dimer Cherenkov light in presence of the scintillation light. Description of the experiment, details of the analysis and preliminary results of the first months of running will be discussed.

  11. Very-High-Energy Astrophysics with the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Mukherjee, Reshmi

    2016-04-01

    The Cherenkov Telescope Array (CTA) will be a new gamma-ray observatory in the energy band ~30 GeV to ~100 TeV, designed to achieve an order of magnitude improvement in sensitivity over the currently operating imaging atmospheric Cherenkov telescopes. CTA will probe known sources with unprecedented sensitivity, angular resolution, and spectral coverage, with the potential of detecting hundreds of new sources. The CTA Consortium will also conduct a number of Key Science Projects, including a Galactic Plane survey and a survey of one quarter of the extragalactic sky. Data taken by CTA will be accessible by members of the wider astronomical community, for the first time in this energy band. This presentation will give an overview of CTA, and its proposed key science program.Submitted with the CTA Consortium

  12. The exposure of the hybrid detector of the Pierre Auger Observatory

    SciTech Connect

    Not Available

    2010-06-01

    The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The 'hybrid' detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.

  13. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Wood, M.; Jogler, T.; Dumm, J.; Funk, S.

    2016-01-01

    We present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies-Cotton (DC) and Schwarzchild-Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30-40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. We attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.

  14. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    DOE PAGESBeta

    Wood, M. D.; Jogler, T.; Dumm, J.; Funk, S.

    2015-06-07

    In this paper, we present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parametersmore » including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. Finally, we attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.« less

  15. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    SciTech Connect

    Wood, M. D.; Jogler, T.; Dumm, J.; Funk, S.

    2015-06-07

    In this paper, we present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. Finally, we attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.

  16. Development of new photon detection device for Cherenkov and fluorescence radiation

    NASA Astrophysics Data System (ADS)

    Aramo, C.; Ambrosio, A.; Ambrosio, M.; Battiston, R.; Castrucci, P.; Cilmo, M.; De Crescenzi, M.; Fiandrini, E.; Guarino, F.; Grossi, V.; Maddalena, P.; Nappi, E.; Passacantando, M.; Pignatel, G.; Santucci, S.; Scarselli, M.; Tinti, A.; Valentini, A.

    2013-06-01

    Recent progress on the development of a new solid state detector allowed the use of finely pixelled photocathodes obtained from silicon semiconductors. SiPM detectors seem to be an ideal tool for the detection of Cherenkov and fluorescence light in spite of their not yet resolved criticism for operating temperature and intrinsic noise. The main disadvantage of SiPM in this case is the poor sensitivity in the wavelength range 300-400 nm, where the Cherenkov light and fluorescence radiation are generated. We report on the possibility to realize a new kind of pixelled photodetector based on the use of silicon substrate with carbon nanotube compounds, more sensitive to the near UV radiation. Also if at the very beginning, the development of such detector appears very promising and useful for astroparticle physics, both in the ground based arrays and in the space experiments. The detectors are ready to be operated in conditions of measurements without signal amplification.

  17. Atmospheric measurements of carbonyl sulfide, dimethyl sulfide, and carbon disulfide using the electron capture sulfur detector

    NASA Technical Reports Server (NTRS)

    Johnson, James E.; Bates, Timothy S.

    1993-01-01

    Measurements of atmospheric dimethyl sulfide (DMS), carbonyl sulfide (COS), and carbon disulfide (CS2) were conducted over the Atlantic Ocean on board the NASA Electra aircraft during the Chemical Instrumentation Test and Evaluation (CITE 3) project using the electron capture sulfur detector (ECD-S). The system employed cryogenic preconcentration of air samples, gas chromatographic separation, catalytic fluorination, and electron capture detection. Samples collected for DMS analysis were scrubbed of oxidants with NaOH impregnated glass fiber filters to preconcentration. The detection limits (DL) of the system for COS, DMS, and CS2 were 5, 5, and 2 ppt, respectively. COS concentrations ranged from 404 to 603 ppt with a mean of 489 ppt for measurements over the North Atlantic Ocean (31 deg N to 41 deg N), and from 395 to 437 ppt with a mean of 419 ppt for measurements over the Tropical Atlantic Ocean (11 deg S to 2 deg N). DMS concentrations in the lower marine boundary layer, below 600-m altitude, ranged from below DL to 150 ppt from flights over the North Atlantic, and from 9 to 104 ppt over the Tropical Atlantic. CS2 concentrations ranged from below DL to 29 ppt over the North Atlantic. Almost all CS2 measurements over the Tropical Atlantic were below DL.

  18. Energy spectrum and chemical composition of cosmic rays between 0.3 and 10 PeV determined from the cherenkov-light and charged-particle distributions in air showers

    NASA Astrophysics Data System (ADS)

    HEGRA-Collaboration; Arqueros, F.; Barrio, J. A.; Bernlöhr, K.; Bojahr, H.; Calle, I.; Contreras, J. L.; Cortina, J.; Deckers, T.; Denninghoff, S.; Fonseca, V.; Gebauer, J.; González, J. C.; Haustein, V.; Heinzelmann, G.; Hohl, H.; Horns, D.; Ibarra, A.; Kestel, M.; Kirstein, O.; Kornmayer, H.; Kranich, D.; Krawczynski, H.; Lindner, A.; Lorenz, E.; Magnussen, N.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Padilla, L.; Petry, D.; Plaga, R.; Prahl, J.; Rauterberg, G.; Rhode, W.; Röhring, A.; Samorski, M.; Schmele, D.; Schröder, F.; Stamm, W.; Wiebel-Sooth, B.; Willmer, M.; Wittek, W.

    2000-07-01

    Measurements of the lateral distribution of Cherenkov photons with the wide-angle atmospheric Cherenkov light detector array AIROBICC and of the charged particle lateral distribution with the scintillator matrix of the HEGRA air-shower detector complex in air showers are reported. They are used in conjunction to determine the energy spectrum and coarse chemical composition of charged cosmic rays in the energy interval from 0.3 PeV to 10 PeV. With the atmospheric shower-front sampling technique these detectors measure the electromagnetic component of an extensive air shower via the lateral density distribution of the shower particles and of the Cherenkov photons. The data are compared with events generated with the CORSIKA program package with the QGSJET hadronic-event generator. Consistency checks performed with primary energy-reconstruction methods based on different shower observables indicate satisfactory agreement between these extensive air shower simulations and the experimental data. This permits to derive results concerning the energy spectrum and composition of charged cosmic rays. The energy spectrum features a so called ``knee'' at an energy of E_knee=3.98+4.66-0.83 (stat) +/- 0.53 (syst) PeV. Power law fits to the differential energy spectrum yield indices of -2.72+0.02-0.03 (stat) +/- 0.07 (syst) below and -3.22+0.47-0.59 (stat) +/- 0.08 (syst) above the knee. The best-fit elongation rate for the whole energy range is determined to 78.3 +/- 1.0 (stat) +/- 6.2 (syst) g/cm2. At the highest energies it seems to decrease slightly. The best-fit fraction of light nuclei decreases from 37 +28-21% (combined statistical and systematic) to 8 +32-8% (combined statistical and systematic) \\ in the energy range discussed here. A detailed study of the systematic errors reveals that a non-changing composition cannot be excluded.

  19. Anomalous Cherenkov spin-orbit sound

    SciTech Connect

    Smirnov, Sergey

    2011-02-15

    The Cherenkov effect is a well-known phenomenon in the electrodynamics of fast charged particles passing through transparent media. If the particle is faster than the light in a given medium, the medium emits a forward light cone. This beautiful phenomenon has an acoustic counterpart where the role of photons is played by phonons and the role of the speed of light is played by the sound velocity. In this case the medium emits a forward sound cone. Here, we show that in a system with spin-orbit interactions in addition to this normal Cherenkov sound there appears an anomalous Cherenkov sound with forward and backward sound propagation. Furthermore, we demonstrate that the transition from the normal to anomalous Cherenkov sound happens in a singular way at the Cherenkov cone angle. The detection of this acoustic singularity therefore represents an alternative experimental tool for the measurement of the spin-orbit coupling strength.

  20. Recent multiwave Cherenkov generator experiments

    SciTech Connect

    Adler, R.; Richter-Sand, R.; Hacker, F.; Walsh, J.; Arman, M.

    1994-12-31

    The initial operating characteristics of the North Star Research Corporation (NSRC) multiwave generator experiment are discussed. The first radiation from the NSRC apparatus has now been observed and the immediate goal is to optimize the power output by providing a beam which is better matched to the field profile (a thinner beam propagating closer to the vanes). When this has been accomplished a detailed comparison of the performance of MWCG/MWDG (multiwave diffraction generator/multiwave Cherenkov generator) structures with BWO structures of the same interaction length will be undertaken.

  1. Cherenkov maser at millimeter wavelengths

    SciTech Connect

    Garate, E.P.; Walsh

    1985-12-01

    The dispersion relation for the transverse magnetic modes (TM/sub 0n/) of a partially filled, dielectric-lined, cylindrical waveguide driven by a cold relativistic electron beam is derived. The effect of a gap between the electron beam and the dielectric liner is included. The dispersion relation is then used to calculate the growth rate for the Cherenkov instability in the collective tenuous-beam limit. Expressions are developed for the minimum current necessary for oscillation threshold and for the power output of the Cerenkov maser in the collective regime.

  2. Calibration and performance of the photon sensor response of FACT — the first G-APD Cherenkov telescope

    NASA Astrophysics Data System (ADS)

    Biland, A.; Bretz, T.; Buß, J.; Commichau, V.; Djambazov, L.; Dorner, D.; Einecke, S.; Eisenacher, D.; Freiwald, J.; Grimm, O.; von Gunten, H.; Haller, C.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Horisberger, U.; Knoetig, M. L.; Krähenbühl, T.; Lustermann, W.; Lyard, E.; Mannheim, K.; Meier, K.; Mueller, S.; Neise, D.; Overkemping, A.-K.; Paravac, A.; Pauss, F.; Rhode, W.; Röser, U.; Stucki, J.-P.; Steinbring, T.; Temme, F.; Thaele, J.; Vogler, P.; Walter, R.; Weitzel, Q.

    2014-10-01

    The First G-APD Cherenkov Telescope (FACT) is the first in-operation test of the performance of silicon photo detectors in Cherenkov Astronomy. For more than two years it is operated on La Palma, Canary Islands (Spain), for the purpose of long-term monitoring of astrophysical sources. For this, the performance of the photo detectors is crucial and therefore has been studied in great detail. Special care has been taken for their temperature and voltage dependence implementing a correction method to keep their properties stable. Several measurements have been carried out to monitor the performance. The measurements and their results are shown, demonstrating the stability of the gain below the percent level. The resulting stability of the whole system is discussed, nicely demonstrating that silicon photo detectors are perfectly suited for the usage in Cherenkov telescopes, especially for long-term monitoring purpose.

  3. Sensivity studies for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Collado, Tarek Hassan

    2015-06-01

    Since the creation of the first telescope in the 17th century, every major discovery in astrophysics has been the direct consequence of the development of novel observation techniques, opening new windows in the electromagnetic spectrum. After Karl Jansky discovered serendipitously the first radio source in 1933, Grote Reber built the first parabolic radio telescope in his backyard, planting the seed of a whole new field in astronomy. Similarly, new technologies in the 1950s allowed the establishment of other fields, such as the infrared, ultraviolet or the X-rays. The highest energy end of the electromagnetic spectrum, the γ-ray range, represents the last unexplored window for astronomers and should reveal the most extreme phenomena that take place in the Universe. Given the technical complexity of γ-ray detection and the extremely relative low fluxes, γ-ray astronomy has undergone a slower development compared to other wavelengths. Nowadays, the great success of consecutive space missions together with the development and refinement of new detection techniques from the ground, has allowed outstanding scientific results and has brought gamma-ray astronomy to a worthy level in par with other astronomy fields. This work is devoted to the study and improvement of the future Cherenkov Telescope Array (CTA), the next generation of ground based γ-ray detectors, designed to observe photons with the highest energies ever observed from cosmic sources.

  4. PyFACT: Python and FITS analysis for Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Raue, Martin; Deil, Christoph

    2012-12-01

    Ground-based very-high energy (VHE; E>100 GeV) gamma-ray astronomy is growing from being conducted by small teams in closed collaborations into a full-fledged branch of astronomy with open observatories. This is best illustrated by the number of known sources: it increased by one order of magnitude in the past ten years, from 10 in the year 2000 to more than 100 in 2010. It is expected that this trend will continue with the next-generation instrument Cherenkov Telescope Array (CTA). This transformation has a profound impact on the data format and analysis of Imaging Atmospheric Cherenkov Telescopes (IACTs). Up to now, IACT data analysis was an internal task performed by specialists with no public access to the data or software. In the future, a large community of VHE astronomers from different scientific topics should be enabled to work with the data. Ease of use, compatibility, and integration with existing astronomy standards and tools will be key. In this contribution, a collection of Python tools for the analysis of data in FITS format (PyFACT; Python and FITS Analysis for Cherenkov Telescopes) is presented, which connects with existing tools like xspec, sherpa, and ds9. The package is available as open source (https://github.com/mraue/pyfact, comments and contributions welcome). Advantages of the chosen ansatz are discussed and implications for future observatories and data archival are presented.

  5. Normalized and asynchronous mirror alignment for Cherenkov telescopes

    NASA Astrophysics Data System (ADS)

    Ahnen, M. L.; Baack, D.; Balbo, M.; Bergmann, M.; Biland, A.; Blank, M.; Bretz, T.; Bruegge, K. A.; Buss, J.; Domke, M.; Dorner, D.; Einecke, S.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Lustermann, W.; Mannheim, K.; Mueller, S. A.; Neise, D.; Neronov, A.; Noethe, M.; Overkemping, A.-K.; Paravac, A.; Pauss, F.; Rhode, W.; Shukla, A.; Temme, F.; Thaele, J.; Toscano, S.; Vogler, P.; Walter, R.; Wilbert, A.

    2016-09-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with large apertures and high image intensities to map the faint Cherenkov light emitted from cosmic ray air showers onto their image sensors. Segmented reflectors fulfill these needs, and as they are composed from mass production mirror facets they are inexpensive and lightweight. However, as the overall image is a superposition of the individual facet images, alignment is a challenge. Here we present a computer vision based star tracking alignment method, which also works for limited or changing star light visibility. Our method normalizes the mirror facet reflection intensities to become independent of the reference star's intensity or the cloud coverage. Using two CCD cameras, our method records the mirror facet orientations asynchronously of the telescope drive system, and thus makes the method easy to integrate into existing telescopes. It can be combined with remote facet actuation, but does not require one to work. Furthermore, it can reconstruct all individual mirror facet point spread functions without moving any mirror. We present alignment results on the 4 m First Geiger-mode Avalanche Cherenkov Telescope (FACT).

  6. First detection of Cherenkov light from cosmic-particle-induced air showers by Geiger-mode avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Biland, A.; Britvitch, I.; Lorenz, E.; Otte, N.; Pauss, F.; Renker, D.; Ritt, S.; Roeser, U.; Schneebeli, M.

    2007-10-01

    We report on first tests of Geiger-mode APDs (G-APD) to detect Cherenkov light from cosmic particle induced air showers. The motivation for this study stems from the requirement to improve the sensitivity of large imaging atmospheric Cherenkov telescopes (IACT) by replacing the photomultipliers (PMT) by high detection efficiency G-APDs. Three tests have been carried out, confirming sufficiently high light sensitivity of blue-sensitive G-APDs as future replacement of PMTs in IACTs.

  7. Distributed beam loss monitor based on the Cherenkov effect in an optical fiber

    NASA Astrophysics Data System (ADS)

    Maltseva, Yu; Emanov, F. A.; Petrenko, A. V.; Prisekin, V. G.

    2015-05-01

    This review discusses a distributed beam loss monitor which is based on the Cherenkov effect in an optical fiber and which has been installed at the VEPP-5 Injection Complex at the Budker Institute of Nuclear Physics. The principle of the device operation consists in detecting the Cherenkov radiation generated in an optical fiber by relativistic charged particles that are produced in an electromagnetic shower when highly relativistic beam particles (electrons or positrons) hit the accelerator vacuum chamber wall. Our experiments used a photomultiplier tube (PMT) to detect the Cherenkov light. Knowing when the PMT signal arrives tells us where the beam loss occurs. Using a 20-m-long optical fiber allowed a detector spatial resolution of 3 m. The way to improve the resolution is to optimize the monitor working conditions and optical fiber and PMT parameters, potentially leading to a resolution of as fine as 0.5 m according to our estimates.

  8. First light of the UV-Detector of the ATMOSUV-CanSat (Atmospheric Thunderstorms's Monitor Optical Signal & UV)

    NASA Astrophysics Data System (ADS)

    Navarro González, Javier; Calvo Diaz-Aldagalán, David; Connell, Paul; Montanya, Joan; Fabró, Ferran; Carrió, Fernando; Blay, Pere; Espinós Morato, Hector; Eyles, Chris; Reglero, Víctor

    2015-04-01

    The ATMOSUV-CanSat is a proposal of small instrument aimed to study the Optical and UV counterpart emission from upper atmosphere high-energy phenomena like TGF (Terrestrial Gamma-ray Flash) process. It could be used also as a complementary ground monitor facility in the study of thunderstorms at high altitude in the atmosphere. The main goal is to perform complementary observations to that of the MXGS/ASIM (Modular X-ray and Gamma-ray Sensor in the Atmosphere-Space Interactions Monitor) mission, at ISS (International Space Station). The detector is planed to be flight during severe thunderstorms and take measurements of air conditions and to perform fast imaging with high temporal accuracy. We expect to measure UV emission and optical signal, complementary temperature, pressure, and accurate 3D location could be obtained also. Here we present preliminary results of a prototype of the UV-Detector ATMOSUVCanSat. The prototype detector has been used for high-speed directional ultraviolet detection from controlled electrical discharges up to 1MV.

  9. Scientific verification of High Altitude Water Cherenkov observatory

    NASA Astrophysics Data System (ADS)

    Marinelli, Antonio; Sparks, Kathryne; Alfaro, Ruben; González, María Magdalena; Patricelli, Barbara; Fraija, Nissim

    2014-04-01

    The High Altitude Water Cherenkov (HAWC) observatory is a TeV gamma-ray and cosmic-ray detector currently under construction at an altitude of 4100 m close to volcano Sierra Negra in the state of Puebla, Mexico. The HAWC [1] observatory is an extensive air-shower array composed of 300 optically isolated water Cherenkov detectors (WCDs). Each WCD contains ~200,000 l of filtered water and four upward-facing photomultiplier tubes. In Fall 2014, when the HAWC observatory will reach an area of 22,000 m2, the sensitivity will be 15 times higher than its predecessor Milagro [2]. Since September 2012, more than 30 WCDs have been instrumented and taking data. This first commissioning phase has been crucial for the verification of the data acquisition and event reconstruction algorithms. Moreover, with the increasing number of instrumented WCDs, it is important to verify the data taken with different configuration geometries. In this work we present a comparison between Monte Carlo simulation and data recorded by the experiment during 24 h of live time between 14 and 15 April of 2013 when 29 WCDs were active.

  10. Studies of Multi-Anode PMTs for a Ring Imaging Cherenkov for CLAS12

    NASA Astrophysics Data System (ADS)

    Lendacky, Andrew; Benmokhtar, Fatiha; Kubarovsky, Valery; Kim, Andrey

    2015-10-01

    At Thomas Jefferson National Accelerator Facility (TJNAF), the CLAS12 detector in Hall B is undergoing an upgrade. A Ring Imaging Cherenkov (R.I.C.H) detector is being built to improve particle identification in the 3-8 GeV/c momentum range. Approximately four hundred Hamamatsu H121700 Multi-Anode Photomultiplier Tubes (MA-PMTs) are being used in this detector to measure photons emitted through Cherenkov Radiation. These MA-PMTs' characteristics are being tested and measured, and I will be presenting my work about the crosstalk study. Crosstalk is the occurrence of incident light striking one area of the photocathode, but is additionally measured in nearby areas. By using a Class 3b laser in the 470 nm wavelength, and an optical density resembling the single photon emission spectrum, the crosstalk for the H121700 MA-PMTs are measured and categorized into a database for future reference.

  11. Cherenkov and Scintillation Properties of Cubic Zirconium

    NASA Technical Reports Server (NTRS)

    Christl, M.J.; Adams, J.H.; Parnell, T.A.; Kuznetsov, E.N.

    2008-01-01

    Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

  12. Data compression for the first G-APD Cherenkov Telescope

    NASA Astrophysics Data System (ADS)

    Ahnen, M. L.; Balbo, M.; Bergmann, M.; Biland, A.; Bretz, T.; Buß, J.; Dorner, D.; Einecke, S.; Freiwald, J.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Lustermann, W.; Lyard, E.; Mannheim, K.; Meier, K.; Mueller, S.; Neise, D.; Neronov, A.; Overkemping, A.-K.; Paravac, A.; Pauss, F.; Rhode, W.; Steinbring, T.; Temme, F.; Thaele, J.; Toscano, S.; Vogler, P.; Walter, R.; Wilbert, A.

    2015-09-01

    The FACT telescope on the Canaries island of La Palma is the first Imaging Atmospheric Cherenkov Telescope (IACT) to use solid state photomultipliers. It generates up to 2 TB of data per night which motivated us to investigate how to reduce the volume of data. Reducing the throughput enables us to efficiently acquire, store and process the observations data. This document presents the conclusions of this work, along with the implementation of the custom compression algorithm and I/O layer that is currently in use to operate the telescope.

  13. Digital FDIRC: A focused differential internal reflection Cherenkov imaged by SiPM arrays

    NASA Astrophysics Data System (ADS)

    Marrocchesi, P. S.; Bagliesi, M. G.; Basti, A.; Bigongiari, G.; Bonechi, S.; Brogi, P.; Checchia, C.; Collazuol, G.; Maestro, P.; Morsani, F.; Piemonte, C.; Stolzi, F.; Suh, J. E.; Sulaj, A.

    2016-07-01

    A prototype of an Internal Reflection Cherenkov, equipped with a SiO2 (fused silica) radiator bar optically connected to a cylindrical mirror, was tested at CERN SPS in March 2015 with a beam of relativistic ions obtained from fragmentation of primary argon nuclei at energies 13, 19 and 30 GeV/n. The detector, designed to identify cosmic nuclei, features an imaging focal plane of dimensions ~ 4 cm × 3 cm equipped with 16 arrays of NUV-SiPM (near-ultraviolet sensitive silicon photon avalanche detector) for a total of 1024 sensitive elements. The outstanding performance of the photodetectors (with negligible background in between adjacent photopeaks) allowed us to apply the technique of photon counting to the Cherenkov light collected on the focal plane. Thanks to the fine granularity of the array elements, the Cherenkov pattern was recorded together with the total number of detected photoelectrons increasing as Z2 as a function of the atomic number Z. In this paper, we report the performance of the SiPM arrays and the excellent resolution achieved by the digital Cherenkov prototype in the charge identification of the elements present in the beam.

  14. Diffraction effects in Cherenkov radiation. Technical report

    SciTech Connect

    Neighbours, J.R.; Buskirk, F.R.

    1983-06-01

    Previous work has shown that microwave Cherenkov radiation from periodic electron bunches occurs at harmonics of the bunch frequency and that the radiation is not necessarily confined to a narrow region centered about the expected Cherenkov angle. This report continues the investigation of the spreading of the radiation and presents the results of numerical calculations of the radiated power per unit solid angle and the total radiated power for physically realizable conditions.

  15. Astroparticle Physics: Detectors for Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Salazar, Humberto; Villaseñor, Luis

    2006-09-01

    We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the measurement of the muon lifetime and the ratio of positive to negative muons in the natural background of cosmic ray muons at 2000 m.a.s.l. Next we describe the detection of decaying and crossing muons in a water Cherenkov detector as well as a technique to separate isolated particles. We also describe the detection of isolated muons and electrons in a liquid scintillator detector and their separation. Next we describe the detection of extensive air showers (EAS) with a hybrid detector array consisting of water Cherenkov and liquid scintillator detectors, located at the campus of the University of Puebla. Finally we describe work in progress to detect EAS at 4600 m.a.s.l. with a water Cherenkov detector array and a fluorescence telescope at the Sierra Negra mountain.

  16. 110th anniversary of the birth of P A Cherenkov (Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 17 December 2014)

    NASA Astrophysics Data System (ADS)

    2015-05-01

    A scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held on 17 December 2014 at the conference hall of the Lebedev Physical Institute, RAS, devoted to the 110th anniversary of the birth of Academician P A Cherenkov. The agenda posted on the website of the Physical Sciences Division RAS http://www.gpad.ac.ru comprised the following reports: (1) Bashmakov Yu A (Lebedev Physical Institute, RAS, Moscow) "Prehistory of discovery"; (2) Kadmensky S G (Voronezh State University, Voronezh) "Cherenkov radiation as a serendipity phenomenon"; (3) Denisov S P (Russian Federation State Scientific Center 'Institute for High Energy Physics' of National Research Center 'Kurchatov Institute', Protvino, Moscow region) "Use of Cherenkov counters in accelerator experiments"; (4) Petrukhin A A (National Research Nuclear University 'MEPhI', Moscow) "Cherenkov NEVOD water detector"; (5) Dremin I M (Lebedev Physical Institute, RAS, Moscow) "Cherenkov radiation from gluons in a nuclear medium"; (6) Domogatsky G V (Institute for Nuclear Research, RAS, Moscow) "Cherenkov detectors for high-energy neutrino astrophysics"; (7) Kravchenko E A (Budker Institute of Nuclear Physics, SB RAS, Novosibirsk) "Cherenkov detectors with aerogel radiators"; (8) Malinovski E I (Institute for Nuclear Research, RAS, Moscow) "Cherenkov total absorption spectrometers for high-energy electrons and photons"; (9) Maltseva Yu I (Budker Institute of Nuclear Physics, SB RAS, Novosibirsk) "Distributed beam loss monitor based on the Cherenkov effect in an optical fiber". Papers based on oral reports 1-4, 6-9 are presented below. Some aspects of report 5 can be found in the review by I M Dremin and A V Leonidov published in 2010 in Physics-Uspekhi (Vol. 53, p. 1123). • Cherenkov radiation: from discovery to RICH, Yu A Bashmakov Physics-Uspekhi, 2015, Volume 58, Number 5, Pages 467-471 • Cherenkov radiation as a serendipitous phenomenon, S G Kadmensky Physics

  17. Asymmetric Cherenkov acoustic reverse in topological insulators

    NASA Astrophysics Data System (ADS)

    Smirnov, Sergey

    2014-09-01

    A general phenomenon of the Cherenkov radiation known in optics or acoustics of conventional materials is a formation of a forward cone of, respectively, photons or phonons emitted by a particle accelerated above the speed of light or sound in those materials. Here we suggest three-dimensional topological insulators as a unique platform to fundamentally explore and practically exploit the acoustic aspect of the Cherenkov effect. We demonstrate that by applying an in-plane magnetic field to a surface of a three-dimensional topological insulator one may suppress the forward Cherenkov sound up to zero at a critical magnetic field. Above the critical field the Cherenkov sound acquires pure backward nature with the polar distribution differing from the forward one generated below the critical field. Potential applications of this asymmetric Cherenkov reverse are in the design of low energy electronic devices such as acoustic ratchets or, in general, in low power design of electronic circuits with a magnetic field control of the direction and magnitude of the Cherenkov dissipation.

  18. ELECTRON–MUON IDENTIFICATION BY ATMOSPHERIC SHOWER AND ELECTRON BEAM IN A NEW EAS DETECTOR CONCEPT

    SciTech Connect

    Iori, M.; Denizli, H.; Yilmaz, A.; Ferrarotto, F.; Russ, J.

    2015-03-10

    We present results demonstrating the time resolution and μ/e separation capabilities of a new concept  for an EAS detector capable of measuring cosmic rays arriving with large zenith angles. This kind of detector has been designed to be part of a large area (several square kilometer) surface array designed to measure ultra high energy (10–200 PeV) τ neutrinos using the Earth-skimming technique. A criterion to identify electron-gammas is also shown and the particle identification capability is tested by measurements in coincidence with the KASKADE-GRANDE experiment in Karlsruhe, Germany.

  19. Results from the SLD barrel CRID detector

    SciTech Connect

    Abe, K.; Antilogus, P. |; Aston, D.

    1993-11-01

    We report on operational experience with and experimental performance of the SLD barrel Cherenkov Ring Imaging Detector from the 1992 and 1993 physics runs. The liquid (C{sub 6}F{sub 14}) and gas (C{sub 5}F{sub 12}) radiator recirculation systems have performed well, and the drift gas supply system has operated successfully with TMAE for three years. Cherenkov rings have been observed from both the liquid and gas radiators. The number and angular resolution of Cherenkov photons have been measured, and found to be close to design specifications.

  20. Strange meson spectroscopy in K[omega] and K[phi] at 11 GeV/c and Cherenkov ring imaging at SLD

    SciTech Connect

    Kwon, Youngjoon.

    1993-01-01

    This thesis consists of two independent parts; development of Cherenkov Ring Imaging Detector (CRID) system and analysis of high-statistics data of strange meson reactions from the LASS spectrometer. Part 1: The CRID system is devoted to charged particle identification in the SLAC Large Detector (SLD) to study e[sup +]e[sup [minus

  1. [Gas chromatography with a Pulsed discharge helium ionization detector for measurement of molecular hydrogen(H2) in the atmosphere].

    PubMed

    Luan, Tian; Fang, Shuang-xi; Zhou, Ling-xi; Wang, Hong-yang; Zhang, Gen

    2015-01-01

    A high precision GC system with a pulsed discharge helium ionization detector was set up based on the commercial Agilent 7890A gas chromatography. The gas is identified by retention time and the concentration is calculated through the peak height. Detection limit of the system is about 1 x 10(-9) (mole fraction, the same as below). The standard deviation of 140 continuous injections with a standard cylinder( concentration is roughly 600 x 10(-9)) is better than 0.3 x 10(-9). Between 409.30 x 10(-9) and 867.74 x 10(-9) molecular hydrogen mole fractions and peak height have good linear response. By using two standards to quantify the air sample, the precision meets the background molecular hydrogen compatibility goal within the World Meteorological Organization/Global Atmosphere Watch (WMO/GAW) program. Atmospheric molecular hydrogen concentration at Guangzhou urban area was preliminarily measured by this method from January to November 2013. The results show that the atmospheric molecular hydrogen mole fraction varies from 450 x 10(-9) to 700 x 10(-9) during the observation period, with the lowest value at 14:00 (Beijing time, the same as below) and the peak value at 20:00. The seasonal variation of atmospheric hydrogen at Guangzhou area was similar with that of the same latitude stations in northern hemisphere.

  2. The Cherenkov Telescope Array For Very High-Energy Astrophysics

    NASA Astrophysics Data System (ADS)

    Kaaret, Philip

    2015-08-01

    The field of very high energy (VHE) astrophysics had been revolutionized by the results from ground-based gamma-ray telescopes, including the current imaging atmospheric Cherenkov telescope (IACT) arrays: HESS, MAGIC and VERITAS. A worldwide consortium of scientists from 29 countries has formed to propose the Cherenkov Telescope Array (CTA) that will capitalize on the power of this technique to greatly expand the scientific reach of ground-based gamma-ray telescopes. CTA science will include key topics such as the origin of cosmic rays and cosmic particle acceleration, understanding extreme environments in regions close to neutron stars and black holes, and exploring physics frontiers through, e.g., the search for WIMP dark matter, axion-like particles and Lorentz invariance violation. CTA is envisioned to consist of two large arrays of Cherenkov telescopes, one in the southern hemisphere and one in the north. Each array will contain telescopes of different sizes to provide a balance between cost and array performance over an energy range from below 100 GeV to above 100 TeV. Compared to the existing IACT arrays, CTA will have substantially better angular resolution and energy resolution, will cover a much wider energy range, and will have up to an order of magnitude better sensitivity. CTA will also be operated as an open observatory and high-level CTA data will be placed into the public domain; these aspects will enable broad participation in CTA science from the worldwide scientific community to fully capitalize on CTA's potential. This talk will: 1) review the scientific motivation and capabilities of CTA, 2) provide an overview of the technical design and the status of prototype development, and 3) summarize the current status of the project in terms of its proposed organization and timeline. The plans for access to CTA data and opportunities to propose for CTA observing time will be highlighed.Presented on behalf of the CTA Consortium.

  3. Measurement of the atmospheric muon flux at 3500 m depth with the NEMO Phase-2 detector

    NASA Astrophysics Data System (ADS)

    Distefano, C.; Aiello, S.; Ameli, F.; Anghinolfi, M.; Barbarino, G.; Barbarito, E.; Barbato, F.; Beverini, N.; Biagi, S.; Bouhadef, B.; Bozza, C.; Cacopardo, G.; Calamai, M.; Calì, C.; Capone, A.; Caruso, F.; Ceres, A.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coniglione, R.; Costa, M.; Cuttone, G.; D'Amato, C.; D'Amico, A.; De Bonis, G.; De Luca, V.; Deniskina, N.; De Rosa, G.; Di Capua, F.; Fermani, P.; Flaminio, V.; Fusco, L. A.; Garufi, F.; Giordano, V.; Gmerk, A.; Grasso, R.; Grella, G.; Hugon, C.; Imbesi, M.; Kulikovskiy, V.; Larosa, G.; Lattuada, D.; Leismueller, K. P.; Leonora, E.; Litrico, P.; Lonardo, A.; Longhitano, F.; Lo Presti, D.; Maccioni, E.; Margiotta, A.; Martini, A.; Masullo, R.; Migliozzi, P.; Migneco, E.; Miraglia, A.; Mollo, C. M.; Mongelli, M.; Morganti, M.; Musico, P.; Musumeci, M.; Nicolau, C. A.; Orlando, A.; Papaleo, R.; Pellegrino, C.; Pellegriti, M. G.; Perrina, C.; Piattelli, P.; Pugliatti, C.; Pulvirenti, S.; Orselli, A.; Raffaelli, F.; Randazzo, N.; Riccobene, G.; Rovelli, A.; Sanguineti, M.; Sapienza, P.; Sciacca, V.; Sgura, I.; Simeone, F.; Sipala, V.; Speziale, F.; Spina, M.; Spitaleri, A.; Spurio, M.; Stellacci, S. M.; Taiuti, M.; Terreni, G.; Trasatti, L.; Trovato, A.; Ventura, C.; Vicini, P.; Viola, S.; Vivolo, D.

    2016-07-01

    In March 2013, the Nemo Phase-2 tower was successfully deployed at 80 km off-shore Capo Passero (Italy) at 3500 m depth. The tower operated continuously until August 2014. We present the results of the atmospheric muon analysis from the data collected in 411 days of live time. The zenith-angle distribution of atmospheric muons was measured and results compared with Monte Carlo simulations. The associated depth intensity relation was then measured and compared with previous measurements and theoretical predictions.

  4. On-site mirror facet condensation measurements for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Dipold, J.; Medina, M. C.; García, B.; Rasztocky, E.; Mancilla, A.; Maya, J.; Larrarte, J. J.; de Souza, V.

    2016-09-01

    The Imaging Atmospheric Cherenkov Technique (IACT) has provided very important discoveries in Very High Energy (VHE) γ-ray astronomy for the last two decades, being exploited mainly by experiments such as H.E.S.S., MAGIC and VERITAS. The same technique will be used by the next generation of γ-ray telescopes, Cherenkov Telescope Array - CTA, which is conceived to be an Observatory composed by two arrays strategically placed in both hemispheres, one in the Northern and one in the Southern. Each site will consist of several tens of Cherenkov telescopes of different sizes and will be equipped with about 10000 m2 of reflective surface. Because of its large size, the reflector of a Cherenkov telescope is composed of many individual mirror facets. Cherenkov telescopes operate without any protective system from weather conditions therefore it is important to understand how the reflective surfaces behave under different environmental conditions. This paper describes a study of the behavior of the mirrors in the presence of water vapor condensation. The operational time of a telescope is reduced by the presence of condensation on the mirror surface, therefore, to control and to monitor the formation of condensation is an important issue for IACT observatories. We developed a method based on pictures of the mirrors to identify the areas with water vapor condensation. The method is presented here and we use it to estimate the time and area two mirrors had condensation when exposed to the environmental conditions in the Argentinean site. The study presented here shows important guidelines in the selection procedure of mirror technologies and shows an innovative monitoring tool to be used in future Cherenkov telescopes.

  5. Detection of Cherenkov light from air showers with Geiger-APDs

    NASA Astrophysics Data System (ADS)

    Otte, A.N. Britvich, I.; Biland, A.; Goebel, F.; Lorenz, E.; Pauss, F.; Renker, D.; Röser, U.; Schweizer, T.

    We have detected Cherenkov light from air showers with Geiger-mode APDs (G-APDs). G-APDs are novel semiconductor photon-detectors which offer several advantages compared to conventional photomultiplier tubes in the field of air shower detection. Folded with the Cherenkov spectrum the response of G-APDs is up to a factor of three higher if compared with classical photomultipliers. Moreover they offer high gain (~105-106) at low operation voltages (<100 V). Under operation they can withstand excessive and prolonged exposure to bright light and are also mechanical robust. Dark count rates of some G-APDs are below the level of light coming from the night sky. Furthermore G-APDs can be mass-produced which allows to considerably reduce the costs of these sensors. According to the present state of the development of G-APD they promise to be a major progress for gamma-ray astronomy. Here we report on the detection of Cherenkov light from air showers with G-APD. We discuss first test results and the advantages and problems of G-APDs in Cherenkov telescopes.

  6. IR detectors for the Infrared Atmospheric Sounding Interferometer (IASI) instrument payload for the METOP-1 ESA polar platform

    NASA Astrophysics Data System (ADS)

    Royer, Michel; Lorans, Dominique; Bischoff, Isabelle; Giotta, Dominique; Wolny, Michel

    1994-12-01

    IASI is an Infrared Atmospheric Sounding Interferometer devoted to the operational meteorology and to atmospheric studies and is to be installed on board the second ESA Polar Platform called METOP-1, planned to be launched in the year 2000. The main purpose of this high performance instrument is to record temperature and humidity profiles. The required lifetime is 4 years. This paper presents the characteristics of the LW IR detection arrays for the IASI spectrometer which consist of HgCdTe de- tectors. SAT has to develop the Engineering Model, Qualification Model and Fight Models of detectors, each having 4 pixels and AR-coated microlenses in a dedicated space housing equipped with a flexible line and a connector. An array is composed of HgCdTe photoconductive detectors. For this long wavelength the array is sensitive from 8.26 micrometers to 15.5 micrometers . The detectors, with sensitive areas of 900 x 900 micrometers 2, are 100 K operating with passive cooling. High quality HgCdTe material is a key feature for the manufacturing of high performance photoconductive detectors. Therefore epitaxial HgCdTe layers are used in this project. These epilayers are grown at CEA/LETI on lattice matched CdZnTe substrates, by Te-rich liquid phase epitaxy, based on a slider technique. The Cd content in the layer is carefully adjusted to meet the required cut off wavelength on the devices. After growth of the epilayers, the samples are annealed under Hg pressure in order to convert them into N type mate- rials. The electrical transport properties of the liquid phase epitaxied wafers are, at 100 K, mobility (mu) over 150,000 cm2/V.s and electrical concentration N of 1.5 1015 cm-3, the residual doping level being 1014 cm-3 at low temperature. On these materials the feasibility study of long wavelength HgCdTe photoconductors has been achieved with the following results: the responsivity is 330 V/W. The bias voltage is Vp=300 mV for a 4 mW limitation of power for each element. The

  7. Controllable passive detectors for study of the radiation environment in space and the atmosphere.

    PubMed

    Akopova, A B

    1998-01-01

    We propose to study the radiation environment on board different flight vehicles: cosmos-type satellites, orbital stations, Space Shuttles and civil (sonic and supersonic) aircraft. These investigations will be carried out with single type of passive detector, namely, nuclear photoemulsions (NPE) with adjustable threshold of particle detection within broad range of linear energy transfer (LET) that is done by means of the technique of selective development of NPE exposed in space. These investigations will allow, one to determine: integral spectra of LET of charged particles of cosmic ray (CR) over a wide range from 2.0 to 5 x 10(4) MeV/cm in biological tissue; differential energy spectra of fast neutrons (1-20 MeV); estimation of absorbed and equivalent doses from charged and neutral component CR; charge and energy spectra of low energy nuclei (E < or = 100 MeV) with Z > or = 2 having in view the extreme hazard radiation to biological objects and microelectronic schemes taken on board inside and outside of these different flight vehicles with exposures from several days to several months. The investigation of radiation environment on board the airplanes depending on the flight parameters will be conducted using emulsions of different sensitivity without any controlling of threshold sensitivity (Akopova et al., 1996). The proposed detector can be used in the joint experiments on the new International Cosmic Station "Alpha".

  8. Determination of the characteristic limits and responses of nuclear track detectors in mixed radon and thoron atmospheres.

    PubMed

    Röttger, Annette; Honig, Anja; Schrammel, Dieter; Strauss, Heinrich F

    2016-03-01

    Closed nuclear track detectors are widely used for the determination of Rn-222 exposures. There are also partial open systems available, which are specially designed for the determination of the exposure to Rn-220, which is a relevant exposure in special workplaces or in specific regions of the world. This paper presents data and a detail analysis of how to determine the cross-correlation by calibration in pure Rn-222 and pure Rn-220 atm. By these means calibration coefficients for the analysis of real mixed atmospheres can be obtained. The respective decision threshold, detection limit and limits of the confidence interval were determined according to ISO 11929 (ISO 11929:2010, 2010). The exposure of detectors was performed at the radon reference chamber and the thoron progeny chamber of the Physikalisch-Technische Bundesanstalt (PTB). The analysis of track response was done at Parc RGM, while the analytical routines were developed in the Leibniz University Hanover, Institute Radioökologie und Strahlenschutz IRS at the working Group AK SIGMA (Arbeitskreis Nachweisgrenzen).

  9. Evaluation of selected detector systems for products formed in the atmospheric hydrolysis of uranium hexafluoride

    SciTech Connect

    Bostick, W.D.; Bostick, D.T.

    1987-03-01

    Sensitive detection of UF/sub 6/ hydrolysis products, either by discontinuous sampling or by continuous or near real-time monitoring, is an important safety consideration for DOE contractors handling large quantities of UF/sub 6/. Automated continuous or rapid intermittent remote sensing of these reaction products can provide an alarm signal when a preselected threshold value has been exceeded (absolute response) or when a significant emission excursion has occurred (rate of change of response). This report evaluates the performance of selected devices for the detection of airborne materials formed in the release of liquid UF/sub 6/ (approx. =1.3 g) into an enclosed volume of 6 m/sup 3/; these experiments were initiated on October 23, 1986. The detection principles investigated are: photometric, gas detector tubes, and electrochemical sensor.

  10. Fluid systems for RICH detectors

    NASA Astrophysics Data System (ADS)

    Ullaland, O.

    2005-11-01

    The optical properties of the radiator media are of prime importance in Ring Imaging Cherenkov detectors. The main requirements for the radiator fluid are a stable refractive index and a photon absorption as low as possible. We will in this note cover some of the cleaning procedures which are required together with distillation and similar separation procedures. Thin film membranes have been introduced during the last decade. They have proven particularly interesting in separating air from some Cherenkov fluids. We will also discuss the use of molecular sieves.

  11. Photon detectors

    SciTech Connect

    Va`vra, J.

    1995-10-01

    J. Seguinot and T. Ypsilantis have recently described the theory and history of Ring Imaging Cherenkov (RICH) detectors. In this paper, I will expand on these excellent review papers, by covering the various photon detector designs in greater detail, and by including discussion of mistakes made, and detector problems encountered, along the way. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photo-electrons. For gaseous devices, this requires the correct choice of gas gain in order to prevent breakdown and wire aging, together with the use of low noise electronics having the maximum possible amplification. In addition, the detector must be constructed of materials which resist corrosion due to photosensitive materials such as, the detector enclosure must be tightly sealed in order to prevent oxygen leaks, etc. The most critical step is the selection of the photocathode material. Typically, a choice must be made between a solid (CsI) or gaseous photocathode (TMAE, TEA). A conservative approach favors a gaseous photocathode, since it is continuously being replaced by flushing, and permits the photon detectors to be easily serviced (the air sensitive photocathode can be removed at any time). In addition, it can be argued that we now know how to handle TMAE, which, as is generally accepted, is the best photocathode material available as far as quantum efficiency is concerned. However, it is a very fragile molecule, and therefore its use may result in relatively fast wire aging. A possible alternative is TEA, which, in the early days, was rejected because it requires expensive CaF{sub 2} windows, which could be contaminated easily in the region of 8.3 eV and thus lose their UV transmission.

  12. A search for neutrino-induced electromagnetic showers in the 2008 combined IceCube and AMANDA detectors

    NASA Astrophysics Data System (ADS)

    Rutledge, Douglas Lowery

    The Antarctic Muon and Neutrino Detector Array (AMANDA) and its successor experiment, IceCube, are both Cherenkov detectors deployed very near the geographic South Pole. The Cherenkov technique uses the light emitted by charged particles that travel faster than the propagation velocity of light in the detector medium. This can be used to detect the daughter particles from the interaction in the ice of neutrinos of all flavors. The topology of neutrino interaction events is strongly dependent on the neutrino flavor, allowing separate measurements to be made. Electrons resulting from neutrino interactions leave spherical events by depositing all of their energy within a small region. Events of this type are often referred to as "Cascades." Muons propagate over long distances, leaving Cherenkov light distributed over a line. The principal event topology for taus is called "Double Bangs," with two spatially separated cascades. There are many potential benefits to running a search for neutrino-induced cascades using the combined readout from both the IceCube and the AMANDA detectors. AMANDA is sensitive to lower energies, owing to its denser distribution of PMTs. IceCube has a much larger volume, allowing it to make better measurements of the background. This allows for better background rejection techniques, and thus a higher final signal rate. This work presents a search for cascades from the atmospheric neutrino flux using the combined data from AMANDA's Transient Waveform Recorder (TWR) data acquisition system, and IceCube's 40 string detector configuration. After the 200 Hz background rate is removed the final measured rate of cascade candidates is 2.5 x 10-7 Hz+3.8x10-7-9.9x10 -8 Hz(stat) +/- 9.8 x 10-8 Hz(syst). The dataset used in this work was collected over 187 days from April to November in 2008.

  13. Tachyonic Cherenkov radiation from supernova remnants

    NASA Astrophysics Data System (ADS)

    Tomaschitz, Roman

    2015-12-01

    The subexponential decay observed in the γ-ray spectral maps of supernova remnants is explained in terms of tachyonic Cherenkov emission from a relativistic electron population. The tachyonic radiation densities of an electronic spinor current are derived, the total density as well as the transversal and longitudinal polarization components, taking account of electron recoil. Tachyonic flux quantization subject to dispersive and dissipative permeabilities is discussed, the matrix elements of the transversal and longitudinal Poynting vectors of the Maxwell-Proca field are obtained, Cherenkov emission angles and radiation conditions are derived. The spectral energy flux of an ultra-relativistic electron plasma is calculated, a tachyonic Cherenkov fit to the high-energy (1 GeV to 30 TeV) γ-ray spectrum of the Crab Nebula is performed, and estimates of the linear polarization degree are given. The spectral tail shows subexponential Weibull decay, which can be modeled with a frequency-dependent tachyon mass in the dispersion relations. Tachyonic flux densities interpolate between exponential and power-law spectral decay, which is further illustrated by Cherenkov fits to the γ-ray spectra of the supernova remnants IC 443 and W44. Subexponential spectral decay is manifested in double-logarithmic spectral maps as curved Weibull or straight power-law slope.

  14. Cherenkov-Raman maser. Doctoral thesis

    SciTech Connect

    Busby, K.O.

    1980-05-01

    The first observations of coherent microwave radiation resulting from Cherenkov-Raman backscattering have been made and are reported. An extensive experimental investigation of vacuum Raman backscattering has also been made. Theoretical models are presented to calculate the frequency and the gain at interaction for both the Raman and the Cerenkov-Raman backscattering interactions. Experimental data are compared to theoretical predictions.

  15. The nonlinear CWFA (Cherenkov Wakefield Accelerator)

    SciTech Connect

    Schoessow, P.

    1989-01-01

    The possible use of nonlinear media to enhance the performance of the Cherenkov Wakefield Accelerator (CWFA) is considered. Numerical experiments have been performed using a new wakefield code which demonstrate larger gradients and transformer ratios in the nonlinear CWFA than are obtained in the linear case. 7 refs., 3 figs.

  16. Performance study of wavelength shifting acrylic plastic for Cherenkov light detection

    NASA Astrophysics Data System (ADS)

    Beckford, B.; De la Puente, A.; Fujii, Y.; Hashimoto, O.; Kaneta, M.; Kanda, H.; Maeda, K.; Matsumura, A.; Nakamura, S. N.; Perez, N.; Reinhold, J.; Tang, L.; Tsukada, K.

    2014-01-01

    The collection efficiency for Cherenkov light incident on a wavelength shifting plate (WLS) has been determined during a beam test at the Proton Synchrotron facility located in the National Laboratory for High Energy Physics (KEK), Tsukuba, Japan. The experiment was conducted in order to determine the detector's response to photoelectrons converted from photons produced by a fused silica radiator; this allows for an approximation of the detector's quality. The yield of the photoelectrons produced through internally generated Cherenkov light as well as light incident from the radiator was measured as a function of the momentum of the incident hadron beam. The yield is proportional to sin2θc, where θc is the opening angle of the Cherenkov light created. Based on estimations and results from similar conducted tests, where the collection efficiency was roughly 39%, the experimental result was expected to be around 40% for internally produced light from the WLS. The results of the experiment determined the photon collection response efficiency of the WLS to be roughly 62% for photons created in a fused silica radiator and 41% for light created in the WLS.

  17. Performance of the CAPRICE98 balloon-borne gas-RICH detector

    NASA Astrophysics Data System (ADS)

    Bergström, D.; Boezio, M.; Carlson, P.; Francke, T.; Grinstein, S.; Weber, N.; Suffert, M.; Hof, M.; Kremer, J.; Menn, W.; Simon, M.; Stephens, S. A.; Ambriola, M.; Bellotti, R.; Cafagna, F.; Castellano, M.; Ciacio, F.; Circella, M.; De Marzo, C.; Finetti, N.; Papini, P.; Piccardi, S.; Spillantini, P.; Bartalucci, S.; Ricci, M.; Bidoli, V.; Casolino, M.; De Pascale, M. P.; Morselli, A.; Picozza, P.; Sparvoli, R.; Barbiellini, G.; Schiavon, P.; Vacchi, A.; Zampa, N.; Mitchell, J. W.; Ormes, J. F.; Streitmatter, R. E.; Bravar, U.; Stochaj, S. J.

    2001-05-01

    A RICH counter using a gas radiator of C 4F 10 and a photosensitive MWPC with pad readout has been developed, tested in particle beam at CERN and used in the CAPRICE98 balloon-borne experiment. The MWPC was operated with a TMAE and ethane mixture at atmospheric pressure and used a cathode pad plane to give an unambiguous image of the Cherenkov light. The induced signals in the pad plane were read out using the AMPLEX chip and CRAMS. The good efficiency of the Cherenkov light collection, the efficient detection of the weak signal from single UV photons together with a low noise level in the electronics of the RICH detector, resulted in a large number of detected photoelectrons per event. For β≃1 charge one particles, an average of 12 photoelectrons per event were detected. The reconstructed Cherenkov angle of 50 mrad for a β≃1 particle had a resolution of 1.2 mrad (rms). The RICH was flown with the CAPRICE98 magnetic spectrometer and was the first RICH counter ever used in a balloon-borne experiment capable of identifying charge one particles at energies above 5 GeV. The RICH provided an identification of cosmic ray antiprotons up to the highest energies ever studied (about 50 GeV of total energy). The spectrometer was flown on 28-29 May 1998 from Fort Sumner, New Mexico, USA.

  18. Evolution of ground-based gamma-ray astronomy from the early days to the Cherenkov Telescope Arrays

    NASA Astrophysics Data System (ADS)

    Hillas, A. M.

    2013-03-01

    Most of what we know of cosmic gamma rays has come from spacecraft, but at energies above tens of GeV it has become possible to make observations with ground-based detectors of enormously greater collecting area. In recent years one such detector type, the cluster of imaging air Cherenkov telescopes, has reached a very productive state, whilst several alternative approaches have been explored, including converted solar power collectors and novel high-altitude particle shower detectors which promised to extend the energy range covered. Key examples of development from 1952 to 2011 are followed, noting the problems and discoveries that stimulated the current work, explaining the logic of the alternative approaches that were taken. The merits of the current major Cherenkov observatories and of other viable detectors are examined and compared, with examples of the astrophysical information they are beginning to provide. The detectors are still evolving, as we still do not understand the processes onto which the gamma rays provide a window. These include the acceleration of Galactic cosmic rays (in particular, the wide-band spectra of radiation from some individual supernova remnants are still hard to interpret), the highly relativistic and variable jets from active galactic nuclei, and aspects of the electrodynamics of pulsars. Larger groups of Cherenkov telescopes still offer the possibility of an increase in power of the technique for resolvable Galactic sources especially.

  19. A First EGRET-UNID-Related Agenda for Cherenkov Telescopes

    NASA Astrophysics Data System (ADS)

    Petry, Dirk

    The next generation of Imaging Atmospheric Cherenkov Telescopes (IACTs) will open the regime between ≈ 30 GeV and 200 GeV to ground-based gamma observations with unprecedented point source sensitivity and source location accuracy. I examine the prospects of observing the unidentified objects (UNIDs) of the Third EGRET Catalog using the IACT observatories currently under construction by the CANGAROO, HESS, MAGIC and VERITAS collaborations. Assuming a modest spectral steepening similar to that observed in the inverse Compton component of the Crab Nebula spectrum and taking into account the sensitivity of the instruments and its zenith angle dependence, a detailed list of 78 observable objects is derived which is then further constrained to 38 prime candidates. The characteristics of this agenda are discussed.

  20. Charge-separated atmospheric neutrino-induced muons in the MINOS far detector

    SciTech Connect

    Adamson, P.; Andreopoulos, Constantinos V.; Arms, Kregg E.; Armstrong, Stephen Randolph; Auty, D.J.; Avvakumov, S.; Ayres, David S.; Baller, Bruce R.; Barish, Barry C.; Barnes, P.D., Jr.; Barr, Giles David; /Oxford U. /Western Washington U.

    2007-01-01

    We found 140 neutrino-induced muons in 854.24 live days in the MINOS far detector, which has an acceptance for neutrino-induced muons of 6.91 x 10{sup 6} cm{sup 2} sr. We looked for evidence of neutrino disappearance in this data set by computing the ratio of the number of low momentum muons to the sum of the number of high momentum and unknown momentum muons for both data and Monte Carlo expectation in the absence of neutrino oscillations. The ratio of data and Monte Carlo ratios, R, is R = 0.65{sub 0.12}{sup +0.15}(stat) {+-} 0.09(syst), a result that is consistent with an oscillation signal. A fit to the data for the oscillation parameters sin{sup 2} 2{theta}{sub 23} and {Delta}m{sub 23}{sup 2} excludes the null oscillation hypothesis at the 94% confidence level. We separated the muons into {mu}{sup -} and {mu}{sup +} in both the data and Monte Carlo events and found the ratio of the total number of {mu}{sup -} to {mu}{sup +} in both samples. The ratio of those ratios, {cflx R}{sub CPT}, is a test of CPT conservation. The result {cflx R}{sub CPT} = 0.72{sub -0.18}{sup +0.24}(stat){sub -0.04}{sup +0.08}(syst), is consistent with CPT conservation.

  1. A new high-density detector for atmospheric neutrinos. Towards neutrino stoichiometry

    NASA Astrophysics Data System (ADS)

    Aglietta, M.; Ambrosio, M.; Aprile, E.; Bologna, G.; Bonesini, M.; Bencivenni, G.; Calvi, M.; Castellina, A.; Curioni, A.; Fulgione, W.; Ghia, P. L.; Gustavino, C.; Kokoulin, R. P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Negri, P.; Paganoni, M.; Periale, L.; Petrukhin, A. A.; Picchi, P.; Pullia, A.; Ragazzi, S.; Redaelli, N.; Satta, L.; Tabarelli de Fatis, T.; Terranova, F.; Tonazzo, A.; Trinchero, G.; Vallania, P.; Villone, B.

    2000-05-01

    A high-density calorimeter, consisting of magnetised iron planes interleaved by RPCs, as tracking and timing devices, is a good candidate for a next generation experiment on atmospheric neutrinos. With 34 kt of mass and in four years of data taking, this experiment will be sensitive to vμ → vχ oscillation with Δm2 > 6 × 10 -5 and mixing near to maximal and fuly cover the region of oscillation parameters suggested by Super-Kamiokande results. Moreover, the experimental method will enable to measure the oscillation parameters from the modulation of the {L}/{E} spectrum ( vμ disappearance). For Δm2 > 3 × 10 -3 eV 2, this experiment can also establish whether the oscillation occurs into a tau or a sterile neutrino, by looking for an excess of muon-less events at high energies produced by upward-going tau neutrinos ( vτ appearance).

  2. The DarkSide-50 outer detectors

    NASA Astrophysics Data System (ADS)

    Westerdale, S.; Agnes, P.; Agostino, L.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Arisaka, K.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Bottino, B.; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadonati, L.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Covone, G.; D’Angelo, D.; D’Incecco, M.; Davini, S.; De Cecco, S.; De Deo, M.; De Vincenzi, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Foster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giganti, C.; Goretti, A. M.; Granato, F.; Grandi, L.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K. R.; Hungerford, E. V.; Aldo, Ianni; Andrea, Ianni; James, I.; Jollet, C.; Keeter, K.; Kendziora, C. L.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Lombardi, P.; Luitz, S.; Ma, Y.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montanari, D.; Monte, A.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Savarese, C.; Segreto, E.; Semenov, D. A.; Shields, E.; Singh, P. N.; DSkorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Vishneva, A.; Vogelaar, B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xu, J.; Yang, C.; Yoo, J.; Zavatarelli, S.; Zec, A.; Zhong, W.; Zhu, C.; Zuzel, G.; The DarkSide Collaboration

    2016-05-01

    DarkSide-50 is a dark matter detection experiment searching for Weakly Interacting Massive Particles (WIMPs), in Gran Sasso National Laboratory. For experiments like DarkSide-50, neutrons are one of the primary backgrounds that can mimic WIMP signals. The experiment consists of three nested detectors: a liquid argon time projection chamber surrounded by two outer detectors. The outermost detector is a 10 m by 11 m cylindrical water Cherenkov detector with 80 PMTs, designed to provide shielding and muon vetoing. Inside the water Cherenkov detector is the 4 m diameter spherical boron-loaded liquid scintillator veto, with a cocktail of pseudocumene, trimethyl borate, and PPO wavelength shifter, designed to provide shielding, neutron vetoing, and in situ measurements of the TPC backgrounds. We present design and performance details of the DarkSide-50 outer detectors.

  3. Study of atmospheric neutrino interactions and search for nucleon decay in Soudan 2

    SciTech Connect

    Leeson, W.R.

    1995-12-14

    Contained event samples, including 30 single-track muon-like events, 35 single-shower electron-like events, and 34 multiprong events, have been obtained from a 1.0 kiloton-year exposure of the Soudan 2 detector. A sample of 15 multiprong events which are partially contained has also been isolated. Properties of these events are used to examine the verity of the atmospheric neutrino flavor ratio anomaly as reported by the Kamiokande and IMB-3 water Cherenkov experiments. The compatibility of the Soudan data with each of two `new physics` explanations for the anomaly, namely proton decay and neutrino oscillations, is investigated. We examine background processes which have not been explicitly treated by the water Cherenkov detectors. Chapters discuss underground non-accelerator particle physics, the atmospheric neutrino anomaly and its interpretation, the Soudan 2 detector and event selection, reconstruction of neutrino events, rock event contamination in Soudan `quasi-elastic` samples, contained multiprong events in Soudan 2, neutrino flavor composition of the multiprong sample, partially contained events in Soudan 2, nucleon decay in Soudan 2, and a summary and discussion. 12 refs., 124 figs., 28 tabs., 7 appendices.

  4. Incidence of rough and irregular atmospheric ice particles from Small Ice Detector 3 measurements

    NASA Astrophysics Data System (ADS)

    Ulanowski, Z.; Kaye, P. H.; Hirst, E.; Greenaway, R. S.; Cotton, R. J.; Hesse, E.; Collier, C. T.

    2013-09-01

    The knowledge of properties of ice crystals such as size, shape, concavity and roughness is critical in the context of radiative properties of ice and mixed phase clouds. Limitations of current cloud probes to measure these properties can be circumvented by acquiring two-dimensional light scattering patterns instead of particle images. Such patterns were obtained in situ for the first time using the Small Ice Detector 3 (SID-3) probe during several flights in a variety of mid-latitude mixed phase and cirrus clouds. The patterns are analyzed using several measures of pattern texture, selected to reveal the magnitude of particle roughness or complexity. The retrieved roughness is compared to values obtained from a range of well-characterized test particles in the laboratory. It is found that typical in situ roughness corresponds to that found in the rougher subset of the test particles, and sometimes even extends beyond the most extreme values found in the laboratory. In this study we do not differentiate between small-scale, fine surface roughness and large-scale crystal complexity. Instead, we argue that both can have similar manifestations in terms of light scattering properties and also similar causes. Overall, the in situ data is consistent with ice particles with highly irregular or rough surfaces being dominant. Similar magnitudes of roughness were found in growth and sublimation zones of cirrus. The roughness was found to be negatively correlated with the halo ratio, but not with other thermodynamic or microphysical properties found in situ. Slightly higher roughness was observed in cirrus forming in clean oceanic airmasses than in a continental, polluted one. Overall, the roughness and complexity is expected to lead to increased shortwave cloud reflectivity, in comparison with cirrus composed of more regular, smooth ice crystal shapes. These findings put into question suggestions that climate could be modified through aerosol seeding to reduce cirrus cover

  5. Incidence of rough and irregular atmospheric ice particles from Small Ice Detector 3 measurements

    NASA Astrophysics Data System (ADS)

    Ulanowski, Z.; Kaye, P. H.; Hirst, E.; Greenaway, R. S.; Cotton, R. J.; Hesse, E.; Collier, C. T.

    2014-02-01

    The knowledge of properties of ice crystals such as size, shape, concavity and roughness is critical in the context of radiative properties of ice and mixed-phase clouds. Limitations of current cloud probes to measure these properties can be circumvented by acquiring two-dimensional light-scattering patterns instead of particle images. Such patterns were obtained in situ for the first time using the Small Ice Detector 3 (SID-3) probe during several flights in a variety of mid-latitude mixed-phase and cirrus clouds. The patterns are analysed using several measures of pattern texture, selected to reveal the magnitude of particle roughness or complexity. The retrieved roughness is compared to values obtained from a range of well-characterized test particles in the laboratory. It is found that typical in situ roughness corresponds to that found in the rougher subset of the test particles, and sometimes even extends beyond the most extreme values found in the laboratory. In this study we do not differentiate between small-scale, fine surface roughness and large-scale crystal complexity. Instead, we argue that both can have similar manifestations in terms of light-scattering properties and also similar causes. Overall, the in situ data are consistent, with ice particles with highly irregular or rough surfaces being dominant. Similar magnitudes of roughness were found in growth and sublimation zones of cirrus. The roughness was found to be negatively correlated with the halo ratio, but not with other thermodynamic or microphysical properties found in situ. Slightly higher roughness was observed in cirrus forming in clean oceanic air masses than in a continental, polluted one. Overall, the roughness and complexity are expected to lead to increased shortwave cloud reflectivity, in comparison with cirrus composed of more regular, smooth ice crystal shapes. These findings put into question suggestions that climate could be modified through aerosol seeding to reduce cirrus

  6. Gaseous Radiation Detectors

    NASA Astrophysics Data System (ADS)

    Sauli, Fabio

    2014-06-01

    1. Introduction; 2. Electromagnetic interactions of charged particles with matter; 3. Interactions of photons and neutrons with matter; 4. Drift and diffusion of charges in gases; 5. Collisional excitations and charge multiplication in uniform fields; 6. Parallel plate counters; 7. Proportional counters; 8. Multiwire proportional chambers; 9. Drift chambers; 10. Time projection chambers; 11. Multitube arrays; 12. Resistive plate chambers; 13. Micro-pattern gas detectors; 14. Cherenkov ring imaging; 15. Miscellaneous detectors and applications; 16. Time degeneracy and aging; Further reading; References; Index.

  7. The mechanism of Vavilov-Cherenkov radiation

    NASA Astrophysics Data System (ADS)

    Kobzev, A. P.

    2010-05-01

    The mechanism of generation of Vavilov-Cherenkov radiation is discussed in this article. The developers of the theory of the Vavilov-Cherenkov effect, I.E. Tamm and I.M. Frank, attributed this effect to their discovery of a new mechanism of radiation when a charged particle moves uniformly and rectilinearly in the medium. As such a mechanism presupposes the violation of the laws of conservation of energy and momentum, they proposed the abolition of these laws to account for the Vavilov-Cherenkov radiation mechanism. This idea has received a considerably wide acceptance in the creation of other theories, for example, transition radiation theory. In this paper, the radiation mechanism for the charge constant motion is demonstrated to be incorrect, because it contradicts not only the laws of conservation of energy and momentum, but also the very definitions of uniform and rectilinear motion (Newton's First Law). A consistent explanation of the Vavilov-Cherenkov radiation microscopic mechanism that does not contradict the basic laws is proposed. It is shown that the radiation arises from the interaction of the moving charge with bound charges that are spaced fairly far away from its trajectory. The Vavilov-Cherenkov radiation mechanism bears a slowing down character, but it differs fundamentally from bremsstrahlung, primarily because the Vavilov-Cherenkov radiation onset results from a two-stage process. First, the moving particle polarizes the medium; then, the already polarized atoms radiate coherently, provided that the particle velocity exceeds the phase speed of light in the medium. If the particle velocity is less than the phase speed of light in the medium, the polarized atoms return energy to the outgoing particle. In this case, radiation is not observed. Special attention is given to the relatively constant particle velocity as the condition of the coherent composition of waves. However, its motion cannot be designated as a uniform and rectilinear one in the

  8. Development of Laser, Detector, and Receiver Systems for an Atmospheric CO2 Lidar Profiling System

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Singh, Upendra

    2008-01-01

    A ground-based Differential Absorption Lidar (DIAL) is being developed with the capability to measure range-resolved and column amounts of atmospheric CO2. This system is also capable of providing high-resolution aerosol profiles and cloud distributions. It is being developed as part of the NASA Earth Science Technology Office s Instrument Incubator Program. This three year program involves the design, development, evaluation, and fielding of a ground-based CO2 profiling system. At the end of a three-year development this instrument is expected to be capable of making measurements in the lower troposphere and boundary layer where the sources and sinks of CO2 are located. It will be a valuable tool in the validation of NASA Orbiting Carbon Observatory (OCO) measurements of column CO2 and suitable for deployment in the North American Carbon Program (NACP) regional intensive field campaigns. The system can also be used as a test-bed for the evaluation of lidar technologies for space-application. This DIAL system leverages 2-micron laser technology developed under a number of NASA programs to develop new solid-state laser technology that provides high pulse energy, tunable, wavelength-stabilized, and double-pulsed lasers that are operable over pre-selected temperature insensitive strong CO2 absorption lines suitable for profiling of lower tropospheric CO2. It also incorporates new high quantum efficiency, high gain, and relatively low noise phototransistors, and a new receiver/signal processor system to achieve high precision DIAL measurements.

  9. Reverse surface-polariton cherenkov radiation.

    PubMed

    Tao, Jin; Wang, Qi Jie; Zhang, Jingjing; Luo, Yu

    2016-01-01

    The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections. PMID:27477061

  10. Pulsar prospects for the Cherenkov telescope array

    NASA Astrophysics Data System (ADS)

    Hassan, T.; Bonnefoy, S.; López, M.; Mirabal, N.; Barrio, J. A.; Contreras, J. L.; de los Reyes, R.; Wilhelmi, E. O.; Rudak, B.; CTA Consortium

    2012-12-01

    In the last few years, the Fermi-LAT telescope has discovered over a 100 pulsars at energies above 100 MeV, increasing the number of known gamma-ray pulsars by an order of magnitude. In parallel, imaging Cherenkov telescopes, such as MAGIC and VERITAS, have detected for the first time VHE pulsed gamma-rays from the Crab pulsar. Such detections have revealed that the Crab VHE spectrum follows a power-law up to at least 400 GeV, challenging most theoretical models, and opening wide possibilities of detecting more pulsars from the ground with the future Cherenkov Telescope Array (CTA). In this contribution, we study the capabilities of CTA for detecting Fermi pulsars. For this, we extrapolate their spectra with "Crab-like" power-law tails in the VHE range, as suggested by the latest MAGIC and VERITAS results.

  11. Reverse surface-polariton cherenkov radiation

    NASA Astrophysics Data System (ADS)

    Tao, Jin; Wang, Qi Jie; Zhang, Jingjing; Luo, Yu

    2016-08-01

    The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections.

  12. Reverse surface-polariton cherenkov radiation.

    PubMed

    Tao, Jin; Wang, Qi Jie; Zhang, Jingjing; Luo, Yu

    2016-01-01

    The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections.

  13. Reverse surface-polariton cherenkov radiation

    PubMed Central

    Tao, Jin; Wang, Qi Jie; Zhang, Jingjing; Luo, Yu

    2016-01-01

    The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections. PMID:27477061

  14. Coaxial configuration of the dielectric Cherenkov maser

    SciTech Connect

    Gavate, E.P.; Fisher, A. . Dept. of Physics); Main, W.G. . Lab. for Plasma Research)

    1990-10-01

    The linearized Lorentz force, continuity equation, and Maxwell's equations are used to calculate the system dispersion relation for a coaxial configuration of the dielectric Cherenkov maser. The system consists of two coaxial conductors lined with dielectric and an annular relativistic electron beam, which propagates between the two liners. Using the linearized dispersion relation, the growth rate for the beam-TM{sub on} waveguide mode instability is calculated in the strong-coupling tenuous beam limit.

  15. Roughness tolerances for Cherenkov telescope mirrors

    NASA Astrophysics Data System (ADS)

    Tayabaly, K.; Spiga, D.; Canestrari, R.; Bonnoli, G.; Lavagna, M.; Pareschi, G.

    2015-09-01

    The Cherenkov Telescope Array (CTA) is a forthcoming international ground-based observatory for very high-energy gamma rays. Its goal is to reach sensitivity five to ten times better than existing Cherenkov telescopes such as VERITAS, H.E.S.S. or MAGIC and extend the range of observation to energies down to few tens of GeV and beyond 100 TeV. To achieve this goal, an array of about 100 telescopes is required, meaning a total reflective surface of several thousands of square meters. Thence, the optimal technology used for CTA mirrors' manufacture should be both low-cost (~1000 euros/m2) and allow high optical performances over the 300-550 nm wavelength range. More exactly, a reflectivity higher than 85% and a PSF (Point Spread Function) diameter smaller than 1 mrad. Surface roughness can significantly contribute to PSF broadening and limit telescope performances. Fortunately, manufacturing techniques for mirrors are now available to keep the optical scattering well below the geometrically-predictable effect of figure errors. This paper determines first order surface finish tolerances based on a surface microroughness characterization campaign, using Phase Shift Interferometry. That allows us to compute the roughness contribution to Cherenkov telescope PSF. This study is performed for diverse mirror candidates (MAGIC-I and II, ASTRI, MST) varying in manufacture technologies, selected coating materials and taking into account the degradation over time due to environmental hazards.

  16. Development of a mid-sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array

    SciTech Connect

    Cameron, Robert A.

    2012-06-28

    The Cherenkov Telescope Array (CTA) is a ground-based observatory for very high-energy (10 GeV to 100 TeV) gamma rays, planned for operation starting in 2018. It will be an array of dozens of optical telescopes, known as Atmospheric Cherenkov Telescopes (ACTs), of 8 m to 24 m diameter, deployed over an area of more than 1 square km, to detect flashes of Cherenkov light from showers initiated in the Earth's atmosphere by gamma rays. CTA will have improved angular resolution, a wider energy range, larger fields of view and an order of magnitude improvement in sensitivity over current ACT arrays such as H.E.S.S., MAGIC and VERITAS. Several institutions have proposed a research and development program to eventually contribute 36 medium-sized telescopes (9 m to 12 m diameter) to CTA to enhance and optimize its science performance. The program aims to construct a prototype of an innovative, Schwarzschild-Couder telescope (SCT) design that will allow much smaller and less expensive cameras and much larger fields of view than conventional Davies-Cotton designs, and will also include design and testing of camera electronics for the necessary advances in performance, reliability and cost. We report on the progress of the mid-sized SCT development program.

  17. Active optics system of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Gardiol, Daniele; Capobianco, Gerardo; Fantinel, Daniela; Giro, Enrico; Lessio, Luigi; Loreggia, Davide; Rodeghiero, Gabriele; Russo, Federico; Volpicelli, Antonio C.

    2014-07-01

    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) SST-2M is an end-to-end prototype of Small Size class of Telescope for the Cherenkov Telescope Array. It will apply a dual mirror configuration to Imaging Atmospheric Cherenkov Telescopes. The 18 segments composing the primary mirror (diameter 4.3 m) are equipped with an active optics system enabling optical re-alignment during telescope slew. The secondary mirror (diameter 1.8 m) can be moved along three degrees of freedom to perform focus and tilt corrections. We describe the kinematic model used to predict the system performance as well as the hardware and software design solution that will be implemented for optics control.

  18. Design and operation of FACT - the first G-APD Cherenkov telescope

    NASA Astrophysics Data System (ADS)

    Anderhub, H.; Backes, M.; Biland, A.; Boccone, V.; Braun, I.; Bretz, T.; Buß, J.; Cadoux, F.; Commichau, V.; Djambazov, L.; Dorner, D.; Einecke, S.; Eisenacher, D.; Gendotti, A.; Grimm, O.; von Gunten, H.; Haller, C.; Hildebrand, D.; Horisberger, U.; Huber, B.; Kim, K.-S.; Knoetig, M. L.; Köhne, J.-H.; Krähenbühl, T.; Krumm, B.; Lee, M.; Lorenz, E.; Lustermann, W.; Lyard, E.; Mannheim, K.; Meharga, M.; Meier, K.; Montaruli, T.; Neise, D.; Nessi-Tedaldi, F.; Overkemping, A.-K.; Paravac, A.; Pauss, F.; Renker, D.; Rhode, W.; Ribordy, M.; Röser, U.; Stucki, J.-P.; Schneider, J.; Steinbring, T.; Temme, F.; Thaele, J.; Tobler, S.; Viertel, G.; Vogler, P.; Walter, R.; Warda, K.; Weitzel, Q.; Zänglein, M.

    2013-06-01

    The First G-APD Cherenkov Telescope (FACT) is designed to detect cosmic gamma-rays with energies from several hundred GeV up to about 10 TeV using the Imaging Atmospheric Cherenkov Technique. In contrast to former or existing telescopes, the camera of the FACT telescope is comprised of solid-state Geiger-mode Avalanche Photodiodes (G-APD) instead of photomultiplier tubes for photo detection. It is the first full-scale device of its kind employing this new technology. The telescope is operated at the Observatorio del Roque de los Muchachos (La Palma, Canary Islands, Spain) since fall 2011. This paper describes in detail the design, construction and operation of the system, including hardware and software aspects. Technical experiences gained after one year of operation are discussed and conclusions with regard to future projects are drawn.

  19. The NA62 RICH detector

    SciTech Connect

    Cassese, A.

    2011-07-01

    The NA62 experiment is designed to measure the very rare kaon decay K{sup +} {yields} {pi}{sup +} at the CERN SPS with a 10% accuracy. The Standard Model prediction for the Branching Ratio is (8.5 {+-} 0.7) x 10{sup -11}. One of the challenging aspect of the experiment is the suppression of the K{sup +} {yields} {mu}{sup +} v{sub {mu}} background at the 10{sup -12} level. To satisfy this requirement a Ring Imaging Cherenkov Detector (RICH), able to separate {pi}{sup {+-}} from {mu}{sup {+-}} in the momentum range between 15 and 35 GeV/c, with a {mu}, rejection factor better than 10{sup -2}, is needed. The RICH must also have a time resolution of about 100 ps to disentangle accidental time associations of beam particles with pions. The RICH will have a very long focal length (17 m) and will be filled with Ne gas at atmospheric pressure. Two test beams were held at CERN in 2007 and 2009 with a RICH prototype. The results of the two test beams will be presented: the {mu}, mis-identification probability is found to be about 0.7% and the time resolution better than 100 ps in the whole momentum range. (authors)

  20. Joint measurement of the atmospheric muon flux through the Puy de Dome volcano with plastic scintillators and Resistive Plate Chambers detectors

    DOE PAGESBeta

    Ambrosino, F.; Anastasio, A.; Bross, A.; Bene, S.; Boivin, P.; Bonechi, L.; Carloganu, C.; Ciaranfi, R.; Cimmino, L.; Combaret, Ch.; et al

    2015-11-14

    The muographic imaging of volcanoes relies on the measured transmittance of the atmospheric muon flux through the target. An important bias affecting the result comes from background contamination mimicking a higher transmittance. The MU-RAY and TOMUVOL collaborations measured independently in 2013 the atmospheric muon flux transmitted through the Puy de Dôme volcano using their early prototype detectors, based on plastic scintillators and on Glass Resistive Plate Chambers, respectively. These detectors had three (MU-RAY) or four (TOMUVOL) detection layers of 1 m2 each, tens (MU-RAY) or hundreds (TOMUVOL) of nanosecond time resolution, a few millimeter position resolution, an energy threshold ofmore » few hundreds MeV, and no particle identification capabilities. The prototypes were deployed about 1.3 km away from the summit, where they measured, behind rock depths larger than 1000 m, remnant fluxes of 1.83±0.50(syst)±0.07(stat) m–2 d–1 deg–2 (MU-RAY) and 1.95±0.16(syst)±0.05(stat) m–2 d–1 deg–2 (TOMUVOL), that roughly correspond to the expected flux of high-energy atmospheric muons crossing 600 meters water equivalent (mwe) at 18° elevation. This implies that imaging depths larger than 500 mwe from 1 km away using such prototype detectors suffer from an overwhelming background. These measurements confirm that a new generation of detectors with higher momentum threshold, time-of-flight measurement, and/or particle identification is needed. As a result, the MU-RAY and TOMUVOL collaborations expect shortly to operate improved detectors, suitable for a robust muographic imaging of kilometer-scale volcanoes.« less

  1. Joint measurement of the atmospheric muon flux through the Puy de Dome volcano with plastic scintillators and Resistive Plate Chambers detectors

    SciTech Connect

    Ambrosino, F.; Anastasio, A.; Bross, A.; Bene, S.; Bonechi, L.; Carloganu, C.; Cimmino, L.; Combaret, Ch.; Durand, S.; Fehr, F.; Gailler, L.; Labazuy, Ph.; Laktineh, I.; Masone, V.; Miallier, D.; Mori, N.; Niess, V.; Pla-Dalmau, A.; Portal, A.; Rubinov, P.; Saracino, G.; Scarlini, E.; Strolin, P.; Vulpescu, B.

    2015-11-14

    The muographic imaging of volcanoes relies on the measured transmittance of the atmospheric muon flux through the target. An important bias affecting the result comes from background contamination mimicking a higher transmittance. The MU-RAY and TOMUVOL collaborations measured independently in 2013 the atmospheric muon flux transmitted through the Puy de Dôme volcano using their early prototype detectors, based on plastic scintillators and on Glass Resistive Plate Chambers, respectively. These detectors had three (MU-RAY) or four (TOMUVOL) detection layers of 1 m2 each, tens (MU-RAY) or hundreds (TOMUVOL) of nanosecond time resolution, a few millimeter position resolution, an energy threshold of few hundreds MeV, and no particle identification capabilities. The prototypes were deployed about 1.3 km away from the summit, where they measured, behind rock depths larger than 1000 m, remnant fluxes of 1.83±0.50(syst)±0.07(stat) m–2 d–1 deg–2 (MU-RAY) and 1.95±0.16(syst)±0.05(stat) m–2 d–1 deg–2 (TOMUVOL), that roughly correspond to the expected flux of high-energy atmospheric muons crossing 600 meters water equivalent (mwe) at 18° elevation. This implies that imaging depths larger than 500 mwe from 1 km away using such prototype detectors suffer from an overwhelming background. These measurements confirm that a new generation of detectors with higher momentum threshold, time-of-flight measurement, and/or particle identification is needed. As a result, the MU-RAY and TOMUVOL collaborations expect shortly to operate improved detectors, suitable for a robust muographic imaging of kilometer-scale volcanoes.

  2. Joint measurement of the atmospheric muon flux through the Puy de Dôme volcano with plastic scintillators and Resistive Plate Chambers detectors

    NASA Astrophysics Data System (ADS)

    Ambrosino, F.; Anastasio, A.; Bross, A.; Béné, S.; Boivin, P.; Bonechi, L.; Cârloganu, C.; Ciaranfi, R.; Cimmino, L.; Combaret, Ch.; D'Alessandro, R.; Durand, S.; Fehr, F.; Français, V.; Garufi, F.; Gailler, L.; Labazuy, Ph.; Laktineh, I.; Lénat, J.-F.; Masone, V.; Miallier, D.; Mirabito, L.; Morel, L.; Mori, N.; Niess, V.; Noli, P.; Pla-Dalmau, A.; Portal, A.; Rubinov, P.; Saracino, G.; Scarlini, E.; Strolin, P.; Vulpescu, B.

    2015-11-01

    The muographic imaging of volcanoes relies on the measured transmittance of the atmospheric muon flux through the target. An important bias affecting the result comes from background contamination mimicking a higher transmittance. The MU-RAY and TOMUVOL collaborations measured independently in 2013 the atmospheric muon flux transmitted through the Puy de Dôme volcano using their early prototype detectors, based on plastic scintillators and on Glass Resistive Plate Chambers, respectively. These detectors had three (MU-RAY) or four (TOMUVOL) detection layers of 1 m2 each, tens (MU-RAY) or hundreds (TOMUVOL) of nanosecond time resolution, a few millimeter position resolution, an energy threshold of few hundreds MeV, and no particle identification capabilities. The prototypes were deployed about 1.3 km away from the summit, where they measured, behind rock depths larger than 1000 m, remnant fluxes of 1.83±0.50(syst)±0.07(stat) m-2 d-1 deg-2 (MU-RAY) and 1.95±0.16(syst)±0.05(stat) m-2 d-1 deg-2 (TOMUVOL), that roughly correspond to the expected flux of high-energy atmospheric muons crossing 600 meters water equivalent (mwe) at 18° elevation. This implies that imaging depths larger than 500 mwe from 1 km away using such prototype detectors suffer from an overwhelming background. These measurements confirm that a new generation of detectors with higher momentum threshold, time-of-flight measurement, and/or particle identification is needed. The MU-RAY and TOMUVOL collaborations expect shortly to operate improved detectors, suitable for a robust muographic imaging of kilometer-scale volcanoes.

  3. First calibration of a Cherenkov beam loss sensor at ALICE using SiPM

    NASA Astrophysics Data System (ADS)

    Intermite, A.; Putignano, M.; Wolski, A.

    2012-06-01

    The need for real-time monitoring of beam losses, including evaluation of their intensity and localization of their exact position, together with the possibility to overcome the limitations due to the reduced space for the diagnostics, makes exploitation of the Cherenkov effect in optical fibres, one of the most suitable candidates for beam loss monitoring. In this article, we report on the first tests of an optical fibre beam loss monitor based on large numerical aperture pure silica fibres and silicon photomultipliers. The tests were carried out at the ALICE accelerator research and development facility, Daresbury Laboratories, UK. In contrast to the results already published where the fibres are longitudinally placed with respect to the accelerator beam path and the losses are multidirectional charged particle showers, for the first time a dedicated set-up with an incident accelerator beam impinging directly on the optical fibre was used for optimizing the collection efficiency of the Cherenkov effect as a function of the incident angle by changing the fibre direction. For this purpose large core fibres were used together with the latest generation silicon detector instead of the standard photomultiplier tubes commonly used for Cherenkov beam loss monitoring. The experiments described in this contribution aim to demonstrate the suitability of the optical fibre sensor for loss monitoring, to optimize the Collection Efficiency (CE) of the Cherenkov photons inside the fibre as a function of the particle incident angle, to calibrate the sensor and calculate its sensitivity, and to understand the limits of temporal resolution of losses from different bunches in the accelerator.

  4. Detection of Shielded Special Nuclear Material With a Cherenkov-Based Transmission Imaging System

    NASA Astrophysics Data System (ADS)

    Rose, Paul; Erickson, Anna; Mayer, Michael; Jovanovic, Igor

    2015-10-01

    Detection of shielded special nuclear material, SSNM, while in transit, offers a unique challenge. Typical cargo imaging systems are Bremsstrahlung-based and cause an abundance of unnecessary signal in the detectors and doses to the cargo contents and surroundings. Active interrogation with dual monoenergetic photons can unveil the illicit material when coupled with a high-contrast imaging system while imparting significantly less dose to the contents. Cherenkov detectors offer speed, resilience, inherent energy threshold rejection, directionality and scalability beyond the capability of most scintillators. High energy resolution is not a priority when using two well separated gamma rays, 4.4 and 15.1 MeV, generated from low energy nuclear reactions such as 11B(d,n- γ)12C. These gamma rays offer a measure of the effective atomic number, Z, of the cargo by taking advantage of the large difference in photon interaction cross sections, Compton scattering and pair production. This imaging system will be coupled to neutron detectors to provide unique signature of SNM by monitoring delayed neutrons. Our experiments confirm that the Cherenkov imaging system can be used with the monoenergetic source to relate transmission and atomic number of the scanned material.

  5. Investigation of Cherenkov Light in an Oil Drum with Cosmic Radiation

    NASA Astrophysics Data System (ADS)

    Wedel, Zachary; Niduaza, Rexavalmar; Castro, Juan; Zavala, Favian; Fan, Sewan; Fatuzzo, Laura

    2014-03-01

    Photomultiplier Tubes (PMTs) have been around for decades and have become well understood in their use as cosmic ray detectors. Multi-Pixel Photon Counters (MPPCs), on the other hand, are still being explored as more viable, cost-effective light detector for counting cosmic rays. To detect cosmic rays by the Cherenkov effect, we placed an acrylic cylinder, with wavelength-shifting fibers coiled around it and filled with distilled water, inside a light-tight box that was able to detect the weak light signals with PMTs (1 and 3 inch), an MPPC (3 mm × 3 mm), and with coincidence between different detectors. Additionally, we utilized an oil drum with approximate volume of 30 gallons as a light-tight vessel to conduct coincidence counts for detecting cosmic rays using the PMTs and MPPCs (3 mm × 3 mm and 1 mm × 1 mm). In this poster presentation, we would present our findings as a comparative analysis between the two different vessels and the efficiency thereof of the same to determine whether or not the MPPC is a viable instrument for detecting cosmic rays that produce Cherenkov light. Department of Education grant number P031S90007.

  6. Cherenkov luminescence imaging in transparent media and the imaging of thin or shallow sources

    PubMed Central

    Komarov, Sergey; Zhou, Dong; Liu, Yongjian; Tai, Yuan-Chuan

    2015-01-01

    Abstract. In this work, we demonstrated the possibility of high spatial resolution Cherenkov luminescence imaging (CLI) for objects in transparent media. We also demonstrated the possibility of the CLI of thin opaque objects using optical transducers. Results demonstrate that submillimeter resolution CLI is achievable for beta-emitting radionuclides, including Br76 that emits positrons of very high energy. The imaging of beta-emitters through scintillation detectors exhibits lower resolution when compared to CLI of the same sources. The application of optical transducers for the CLI was demonstrated using plants labeled with CO112 and phantoms containing beta-emitters. PMID:25789422

  7. Cherenkov emission provides detailed picture of non-thermal electron dynamics in the presence of magnetic islands

    NASA Astrophysics Data System (ADS)

    Causa, F.; Buratti, P.; Esposito, B.; Pucella, G.; Giovannozzi, E.; Jakubowski, L.; Malinowski, K.; Rabinski, M.; Sadowski, M. J.; Zebrowski, J.; the FTU Team

    2015-11-01

    Results from a Cherenkov probe recently installed in FTU are presented on non-thermal electron losses. A range of scenarios are investigated to prove the versatility of the diagnostics by correlation with several other diagnostics, including electron cyclotron emission (ECE), neutron and gamma ray detectors, Mirnov coils and soft x-ray cameras. The data analysed provide useful insights into the dynamics of runaway electron (RE) losses in the presence of magnetic islands, demonstrating the distinct and broad potential of this relatively new diagnostic system. The analysis focuses on the sensitivity of the Cherenkov probe to RE losses in connection with magnetohydrodynamic activity and, generally, with magnetic perturbations and reconnection events. In those cases, the Cherenkov probe signals show that the RE expulsion mechanisms are due to the magnetic perturbation of a magnetic island and its amplitude fluctuations. Importantly, the microsecond resolution of the Cherenkov diagnostics reveals an internal structure of the signal peaks, permitting, for the first time with non-magnetic diagnostics, the detection of high frequency signals linked to perturbations of the magnetic island width, known as beta-induced Alfvèn eigenmodes.

  8. Representations and image classification methods for Cherenkov telescopes

    SciTech Connect

    Malagon, C.; Parcerisa, D. S.; Barrio, J. A.; Nieto, D.

    2008-05-29

    The problem of identifying gamma ray events out of charged cosmic ray background (so called hadrons) in Cherenkov telescopes is one of the key problems in VHE gamma ray astronomy. In this contribution, we present a novel approach to this problem by implementing different classifiers relying on the information of each pixel of the camera of a Cherenkov telescope.

  9. Time calibration with atmospheric muon tracks in the ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Adrián-Martínez, S.; Albert, A.; André, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bogazzi, C.; Bormuth, R.; Bou-Cabo, M.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Dekeyser, I.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Dumas, A.; Eberl, T.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fermani, P.; Flaminio, V.; Folger, F.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Gracia-Ruiz, R.; Gómez-González, J. P.; Graf, K.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herrero, A.; Hößl, J.; Hofestädt, J.; Hugon, C.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kooijman, P.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Lattuada, D.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Martini, S.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Neff, M.; Nezri, E.; Păvălaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Richter, R.; Roensch, K.; Rostovtsev, A.; Saldaña, M.; Samtleben, D. F. E.; Sánchez-Losa, A.; Sanguineti, M.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schulte, S.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Taiuti, M.; Tamburini, C.; Trovato, A.; Tselengidou, M.; Tönnis, C.; Turpin, D.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Visser, E.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.

    2016-05-01

    The ANTARES experiment consists of an array of photomultipliers distributed along 12 lines and located deep underwater in the Mediterranean Sea. It searches for astrophysical neutrinos collecting the Cherenkov light induced by the charged particles, mainly muons, produced in neutrino interactions around the detector. Since at energies of ∼10 TeV the muon and the incident neutrino are almost collinear, it is possible to use the ANTARES detector as a neutrino telescope and identify a source of neutrinos in the sky starting from a precise reconstruction of the muon trajectory. To get this result, the arrival times of the Cherenkov photons must be accurately measured. A to perform time calibrations with the precision required to have optimal performances of the instrument is described. The reconstructed tracks of the atmospheric muons in the ANTARES detector are used to determine the relative time offsets between photomultipliers. Currently, this method is used to obtain the time calibration constants for photomultipliers on different lines at a precision level of 0.5 ns. It has also been validated for calibrating photomultipliers on the same line, using a system of LEDs and laser light devices.

  10. Cherenkov-Vavilov Formulation of X Waves

    SciTech Connect

    Walker, S. C.; Kuperman, W. A.

    2007-12-14

    The field from a supersonic (or equivalently superluminal) point source in uniform motion [i.e., the Cherenkov-Vavilov (CV) effect] is shown to be equivalent to the diffractionless X-wave field. It is demonstrated that the power required to support an X wave is equivalent to the power dissipated by a CV source. In the context of the CV solution, it is clear that any supersonic or superluminal properties exhibited by X waves are purely phase effects. As a consequence, X waves cannot propagate a signal faster than the speed of waves, and thus necessarily obey the law on the finiteness of information transfer.

  11. Cherenkov radiation as a serendipitous phenomenon

    NASA Astrophysics Data System (ADS)

    Kadmensky, S. G.

    2015-05-01

    A brief account is given of P A Cherenkov's Voronezh years, a period during which the future Nobel laureate in physics attended school (in the village of Novaya Chigla near Voronezh) and studied at Voronezh State University. The history of the serendipitous discovery of the radiation which was to be named after him is described and its importance for modern science is discussed. Possible modern approaches are considered to explain — without using the concept of 'cold nuclear synthesis' — some other unexpected experimental results on the nonthermonuclear fusion of light nuclei stimulated by electron beams and by laser and gamma radiations.

  12. Radio telescopes as the detectors of super-high-energy neutrinos

    NASA Technical Reports Server (NTRS)

    Dagkesamansky, R. D.; Zheleznykh, I. M.

    1991-01-01

    The registration of super high energy neutrinos is a very difficult and also very important problem that requires construction of detectors with large effective target masses. Askaryan pointed out the possibility of registering cascades in dense media by the Cherenkov radio emission of an excess of negative charges in the cascades which arose in interaction between high energy particles and the atoms of medium. The telescopes for cosmic high energy neutrino detection by radioemission of cascades induced underground, but whose development continues in the atmosphere were proposed by others. The effective target masses of such detectors could be approx. 10(exp 9) tons and more. The properties of Cherenkov radio emission of cascades and the properties of ice in the Antarctic Region make it possible to propose Radio Antarctic Muon and Neutrino Detection (RAMAND): antennas should be placed on the ice surface of approx. 10 sq km to search for radio signals for neutrino (muon) cascades of energy. It is evident from data given that the largest radio telescopes gives the opportunity for registration of the cascades induced by neutrinos with the energies E is greater than or = 10(exp 20) eV.

  13. Latest news from the High Altitude Water Cherenkov Observatory

    NASA Astrophysics Data System (ADS)

    González Muñoz, A.; HAWC Collaboration

    2016-07-01

    The High Altitude Water Cherenkov Observatory is an air shower detector designed to study very-high-energy gamma rays (∼ 100 GeV to ∼ 100 TeV). It is located in the Pico de Orizaba National Park, Mexico, at an elevation of 4100 m. HAWC started operations since August 2013 with 111 tanks and in April of 2015 the 300 tanks array was completed. HAWC's unique capabilities, with a field of view of ∼ 2 sr and a high duty cycle of 5%, allow it to survey 2/3 of the sky every day. These features makes HAWC an excellent instrument for searching new TeV sources and for the detection of transient events, like gamma-ray bursts. Moreover, HAWC provides almost continuous monitoring of already known sources with variable gamma-ray fluxes in most of the northern and part of the southern sky. These observations will bring new information about the acceleration processes that take place in astrophysical environments. In this contribution, some of the latest scientific results of the observatory will be presented.

  14. Latest news from the High Altitude Water Cherenkov Observatory

    NASA Astrophysics Data System (ADS)

    González Muñoz, A.; HAWC Collaboration

    2016-07-01

    The High Altitude Water Cherenkov Observatory is an air shower detector designed to study very-high-energy gamma rays (˜ 100 GeV to ˜ 100 TeV). It is located in the Pico de Orizaba National Park, Mexico, at an elevation of 4100 m. HAWC started operations since August 2013 with 111 tanks and in April of 2015 the 300 tanks array was completed. HAWC's unique capabilities, with a field of view of ˜ 2 sr and a high duty cycle of 5%, allow it to survey 2/3 of the sky every day. These features makes HAWC an excellent instrument for searching new TeV sources and for the detection of transient events, like gamma-ray bursts. Moreover, HAWC provides almost continuous monitoring of already known sources with variable gamma-ray fluxes in most of the northern and part of the southern sky. These observations will bring new information about the acceleration processes that take place in astrophysical environments. In this contribution, some of the latest scientific results of the observatory will be presented.

  15. [Results of the EGRET Detector Program

    NASA Technical Reports Server (NTRS)

    Carter-Lewis, D. A.

    1998-01-01

    This NASA grant has funded studies of cosmic objects observed by both the EGRET detector aboard the Compton Gamma-ray Observatory and Whipple Gamma-ray imaging telescope. The former has sensitivity up to a few GeV and latter has sensitivity starting at about 200 GeV extending up to beyond 10 TeV. Thus these instruments probe some of the most energetic phenomena in the universe. This program has been in place for several years and led to important results referred to below. The Whipple Observatory Imaging Cherenkov Telescope consists of a 10-meter reflector with a nanosecond photomultiplier-tube camera at the focal plane. During the time period covered by this grant, it had either 109 pixels or 151 pixels on a 1/4 degree hexagonal pattern. As a TeV gamma ray enters the atmosphere, it produces an electron/positron pair initiating an extensive air shower. Cherenkov light from the electrons and positrons in the shower form an image of the shower at the phototube camera. The shape and intensity of this image is used to distinguish gamma-ray initiated showers from cosmic-ray (largely proton and alpha-particle) background showers and to derive an energy estimate for the primary gamma-ray. The Whipple Observatory gamma-ray collaboration pioneered this imaging technique which normally rejects over 99 percent of the cosmic-ray background while keeping over 70 percent of the gamma-ray signal. One of its key features is 2 large collection area which can exceed 50,000 meters. This grant covered primarily correlated observations of Markarian 421 and observations of the Cygnus region. The former resulted in a multiwavelength campaign showing correlations in several wavebands. The TeV data showed dramatic variability with the emission characterized by day-scale flickering and with now well defined steady component.

  16. The camera of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Catalano, Osvaldo; Maccarone, Maria C.; Gargano, Carmelo; La Rosa, Giovanni; Segreto, Alberto; Sottile, Giuseppe; De Caprio, Vincenzo; Russo, Francesco; Capalbi, Milvia; Sangiorgi, Pierluca; Bonanno, Giovanni; Grillo, Alessandro; Garozzo, Salvatore; Marano, Davide; Billotta, Sergio; Romeo, Giuseppe; Stringhetti, Luca; Fiorini, Mauro; La Palombara, Nicola; Incorvaia, Salvatore; Toso, Giorgio; Impiombato, Domenico; Giarrusso, Salvatore

    2014-07-01

    In the context of the Cherenkov Telescope Array observatory project, the ASTRI SST-2M end-to-end prototype telescope, entirely supported by the Italian National Institute of Astrophysics, is designed to detect cosmic primary gamma ray energies from few TeV up to hundreds of TeV. The ASTRI SST-2M prototype camera is part of the challenging synergy of novel optical design, camera sensors, front-end electronics and telescope structure design. The camera is devoted to imaging and recording the Cherenkov images of air showers induced by primary particles into the Earth's atmosphere. In order to match the energy range mentioned above, the camera must be able to trigger events within a few tens of nanoseconds with high detection efficiency. This is obtained by combining silicon photo-multiplier sensors and suitable front-end electronics. Due to the characteristic imprint of the Cherenkov image that is a function of the shower core distance, the signal dynamic range of the pixels and consequently of the front-end electronics must span three orders of magnitude (1:1000 photo-electrons). These and many other features of the ASTRI SST-2M prototype camera will be reported in this contribution together with a complete overview of the mechanical and thermodynamic camera system.

  17. Signal acquisition in Cherenkov-type diagnostics of electron beams within tokamak facilities

    NASA Astrophysics Data System (ADS)

    Rabiński, Marek; Jakubowski, Lech; Sadowski, Marek J.; Żebrowski, Jarosław; Jakubowski, Marcin J.; Malinowski, Karol; Mirowski, Robert

    2015-09-01

    The paper presents feasibility and design studies of Cherenkov-type probes, a development of the measuring head construction designed for different tokamak devices, and in particular the acquisition of optical signals to a data storage system. In order to lower the energy threshold of the electron detection the authors applied radiators with the highest values of the refractive index. Different radiator materials, such as aluminium nitride and CVD diamond were applied. Several versions of measuring heads and different manipulators, e.g., a movable vacuum-tight shaft or a fast-moving reciprocating probe, were manufactured and used. The practical application of the Cherenkov probes required also a consideration of spectral characteristics of optical fibres and photomultipliers. The Cherenkov radiation, as generated inside the radiators, is lead out through separate fibres (optical cables) to the atmospheric pressure side. The emitted radiation in the blue (near ultraviolet) spectrum range should be collected and delivered through appropriate optical cables to a control room, amplified within photomultipliers and recorded in a digital form. In order to investigate an electron energy distribution the multi-channel probes have also been designed and applied.

  18. The Potential of Spaced-based High-Energy Neutrino Measurements via the Airshower Cherenkov Signal

    NASA Technical Reports Server (NTRS)

    Krizmanic, John F.; Mitchell, John W.

    2011-01-01

    Future space-based experiments, such as (Orbiting Wide-angle Light Collectors (OWL) and JEM-EUSO, view large atmospheric and terrestrial neutrino targets. With energy thresholds slightly above 10(exp 19) eV for observing airshowers via air fluorescence, the potential for observing the cosmogenic neutrino flux associated with the GZK effect is limited. However, the forward Cherenkov signal associated with the airshower can be observed at much lower energies. A simulation was developed to determine the Cherenkov signal strength and spatial extent at low-Earth orbit for upward-moving airshowers. A model of tau neutrino interactions in the Earth was employed to determine the event rate of interactions that yielded a tau lepton which would induce an upward-moving airshower observable by a space-based instrument. The effect of neutrino attenuation by the Earth forces the viewing of the Earth's limb to observe the vT-induced Cherenkov airshower signal at above the OWL Cherenkov energy threshold of approximately 10(exp 16.5) eV for limb-viewed events. Furthermore, the neutrino attenuation limits the effective terrestrial neutrino target area to approximately 3 x 10(exp 5) square km at 10(exp 17) eV, for an orbit of 1000 km and an instrumental full Field-of-View of 45 deg. This translates into an observable cosmogenic neutrino event rate of approx. l/year based upon two different models of the cosmogenic neutrino flux, assuming neutrino oscillations and a 10% duty cycle for observation.

  19. A Cherenkov-emission microwave source

    SciTech Connect

    Yoshii, J.; Lai, C.H.; Katsouleas, T.; Hairapetian, G.; Joshi, C.; Mori, W.

    1996-12-31

    In an unmagnetized plasma, there is no Cherenkov emission because the phase velocity {nu}{sub {phi}} of light is greater than c. In a magnetized plasma, the situation is completely changed. There is a rich variety of plasma modes with phase velocities {nu}{sub {phi}} {le} c which can couple to a fast particle. In the magnetized plasma, a fast particle or particle beam excites a Cherenkov wake that has both electrostatic and electromagnetic components. Preliminary simulations indicate that at the vacuum/plasma boundary, the wake couples to a vacuum microwave with an amplitude equal to the electromagnetic component in the plasma. For a weakly magnetized plasma, the amplitude of the outcoupled radiation is approximately {omega}{sub c}/{omega}{sub p} times the amplitude of the wake excited in the plasma by the beam, and the frequency is approximately w{sub p}. Since plasma wakes as high as 100 MeV/m are expected in near-term experiments, the potential for a high-power, coherent microwave to THz source exists. In this talk, a brief overview of the scaling laws will be presented, followed by 1-D and 2-D PIC simulations. Prospects for a tunable microwave source experiment based on this mechanism at the UCLA plasma wakefield accelerator facility will be discussed.

  20. A microwave inverse Cherenkov accelerator (MICA)

    NASA Astrophysics Data System (ADS)

    Zhang, T. B.; Marshall, T. C.

    1996-02-01

    By "inverting" the stimulated Cherenkov effect to stimulated Cherenkov absorption, it is possible to build an electron accelerator device driven by high power microwaves that propagate in a slow-wave TM mode (axial E-field). In this paper, we have solved for the wave dispersion in the structure, found the field distributions, and then used the Lorentz force equations to obtain the motion of a group of electrons distributed in radius and velocity. We find the radial forces are focusing. Electrons in a well-defined filament ( r < 0.5 mm) remain collimated and do not strike the dielectric. By using the 15 MW of rf power available at 2.865 GHz, we can accelerate an electron beam (˜6 MeV, few ps pulses) to energy ˜16 MeV. This results in a relatively compact structure that has the advantage of a smooth-bore design and no need of magnetic focusing. The techniques for improving the dielectric breakdown the surface should permit axial fields in the range of 100-200 kV/cm.

  1. THE DIRC Detector at BaBar

    SciTech Connect

    Ratcliff, Blair N

    1999-10-12

    A dedicated particle identification system based on the Detection of Internally Reflected Cherenkov (DIRC) light will be used in the BaBar detector. We provide an overview of the DIRC concept, design, and expected performance of the production device and a status report on its construction and commissioning. The DIRC is expected to be operating in the BaBar detector on beam line at the PEP-II B Factory in late spring 1999.

  2. Oscillations of very low energy atmospheric neutrinos

    SciTech Connect

    Peres, Orlando L. G.; Smirnov, A. Yu.

    2009-06-01

    There are several new features in the production, oscillations, and detection of the atmospheric neutrinos of low energies E < or approx. 100 MeV. The flavor ratio r of muon to electron neutrino fluxes is substantially smaller than 2 and decreases with energy, a significant part of events is due to the decay of invisible muons at rest, etc. Oscillations in a two-layer medium (atmosphere-Earth) should be taken into account. We derive analytical and semianalytical expressions for the oscillation probabilities of these 'sub-sub-GeV' neutrinos. The energy spectra of the e-like events in water Cherenkov detectors are computed, and the dependence of the spectra on the 2-3 mixing angle {theta}{sub 23}, the 1-3 mixing, and the CP-violation phase are studied. We find that variations of {theta}{sub 23} in the presently allowed region change the number of e-like events by about 15%-20% as well as lead to distortion of the energy spectrum. The 1-3 mixing and CP violation can lead to {approx}10% effects. Detailed study of the sub-sub-GeV neutrinos will be possible in future megaton-scale detectors.

  3. Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams

    SciTech Connect

    Adli, E.; Gessner, S. J.; Corde, S.; Hogan, M. J.; Bjerke, H. H.

    2015-02-09

    We describe a beam profile monitor design based on Cherenkov light emitted from a charged particle beam in an air gap. The main components of the profile monitor are silicon wafers used to reflect Cherenkov light onto a camera lens system. The design allows for measuring large beam sizes, with large photon yield per beam charge and excellent signal linearity with beam charge. Furthermore, the profile monitor signal is independent of the particle energy for ultrarelativistic particles. Different design and parameter considerations are discussed. A Cherenkov light-based profile monitor has been installed at the FACET User Facility at SLAC. Finally, we report on the measured performance of this profile monitor.

  4. Cherenkov maser and Cherenkov laser devices. Final report, 10 September 1979-9 September 1982

    SciTech Connect

    Walsh, J.E.

    1982-12-01

    Four documents, which together serve as a review of experimental verification and the theoretical description of stimulated Cherenkov masers, is presented. Multi-hundred kW power levels have been obtained in the longer mm wavelength range and significant power at wavelengths shorter than 1.5 mm have been observed. The relations between resonator dimensions and beam parameters which determine wavelength, gain, and output power, have been established.

  5. Measurement of atmospheric NO2 and NOx by a small, sensitive diode laser based cavity ring-down detector at 404 nm

    NASA Astrophysics Data System (ADS)

    Fuchs, H.; Dubé, W. P.; Lerner, B. M.; Wagner, N. L.; Williams, E. J.; Brown, S. S.

    2009-04-01

    A new, cavity ring-down detector was developed for the detection of atmospheric NO2 and NOx. NO2 is directly measured by laser diode based cavity ring-down spectroscopy at 404 nm. In contrast to the indirect detection in most commonly used chemiluminescence detectors, the direct measurement of NO2 may be useful especially in cases where NO to NO2 ratios are large such as in freshly emitted plumes from combustion processes. The extinction of ambient air is dominated by the absorption of NO2 so that the instrument does not exhibit significant interferences due to other absorbers such as ozone or water vapor. The limit of detection is 22 pptv (2σ precision) for NO2 at 1 s time resolution. The accuracy of the NO2 measurement is given by the uncertainty of the NO2 absorption cross section to

  6. Calibration of the Cherenkov telescope array using cosmic ray electrons

    NASA Astrophysics Data System (ADS)

    Parsons, R. D.; Hinton, J. A.; Schoorlemmer, H.

    2016-11-01

    Cosmic ray electrons represent a background for gamma-ray observations with Cherenkov telescopes, initiating air-showers which are difficult to distinguish from photon-initiated showers. This similarity, however, and the presence of cosmic ray electrons in every field observed, makes them potentially very useful for calibration purposes. Here we study the precision with which the relative energy scale and collection area/efficiency for photons can be established using electrons for a major next generation instrument such as CTA. We find that variations in collection efficiency on hour timescales can be corrected to better than 1%. Furthermore, the break in the electron spectrum at ∼ 0.9 TeV can be used to calibrate the energy scale at the 3% level on the same timescale. For observations on the order of hours, statistical errors become negligible below a few TeV and allow for an energy scale cross-check with instruments such as CALET and AMS. Cosmic ray electrons therefore provide a powerful calibration tool, either as an alternative to intensive atmospheric monitoring and modelling efforts, or for independent verification of such procedures.

  7. The MINOS detectors

    SciTech Connect

    Habig, A.; Grashorn, E.W.; /Minnesota U., Duluth

    2005-07-01

    The Main Injector Neutrino Oscillation Search (MINOS) experiment's primary goal is the precision measurement of the neutrino oscillation parameters in the atmospheric neutrino sector. This long-baseline experiment uses Fermilab's NuMI beam, measured with a Near Detector at Fermilab, and again 735 km later using a Far Detector in the Soudan Mine Underground Lab in northern Minnesota. The detectors are magnetized iron/scintillator calorimeters. The Far Detector has been operational for cosmic ray and atmospheric neutrino data from July of 2003, the Near Detector from September 2004, and the NuMI beam started in early 2005. This poster presents details of the two detectors.

  8. Search for long-lived heavy charged particles using a ring imaging Cherenkov technique at LHCb

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A., Jr.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casanova Mohr, R.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S. F.; Chiapolini, N.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C. T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Gianì, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. N.; Mitzel, D. S.; Molina Rodriguez, J.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Müller, J.; Müller, K.; Müller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ubeda Garcia, M.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.

    2015-12-01

    A search is performed for heavy long-lived charged particles using 3.0 fb^{-1} of proton-proton collisions collected at √{s} = 7 and 8 TeV with the LHCb detector. The search is mainly based on the response of the ring imaging Cherenkov detectors to distinguish the heavy, slow-moving particles from muons. No evidence is found for the production of such long-lived states. The results are expressed as limits on the Drell-Yan production of pairs of long-lived particles, with both particles in the LHCb pseudorapidity acceptance, 1.8 < η < 4.9. The mass-dependent cross-section upper limits are in the range 2-4 fb (at 95 % CL) for masses between 14 and 309 { GeV/c^2}.

  9. Nonlinear theory of a plasma Cherenkov maser

    SciTech Connect

    Choi, J.S.; Heo, E.G.; Choi, D.I.

    1995-12-31

    The nonlinear saturation state in a plasma Cherenkov maser (PCM) propagating the intense relativistic electron beam through a circular waveguide partially filled with a dense annular plasma, is analyzed from the nonlinear formulation based on the cold fluid-Maxwell equations. We obtain the nonlinear efficiency and the final operation frequency under consideration of the effects of the beam current, the beam energy and the slow wave structure. We show that the saturation mechanism of a PCM instablity is a close correspondence in that of the relativistic two stream instability by the coherent trapping of electrons in a single most-ustable wave. And the optimal conditions in PCM operation are also obtained from performing our nonliear analysis together with computer simulations.

  10. Plasma-filled dielectric Cherenkov maser

    SciTech Connect

    Kosai, H.; Garate, E.P.; Fisher, A. . Dept. of Physics)

    1990-12-01

    The effect of a background plasma on a dielectric Cherenkov maser is examined by solving the linearized, beam-plasma, dielectric-lined waveguide dispersion relation. The results indicate that introduction of the background plasma can produce a higher spatial growth rate for the beam-waveguide instability and can reduce the electric field at the dielectric surface when compared to the system with no background plasma present. Also, it is found that for some sets of waveguide parameters, the TM{sub On} electromagnetic modes can propagate frequencies that are below the background plasma frequency in the system. These modes have a finite cut-off frequency and are different from the Trivelpiece-Gould modes for the system.

  11. Micro-channel plate photon detector studies for the TORCH detector

    NASA Astrophysics Data System (ADS)

    Castillo García, L.; Brook, N.; Cowie, E. N.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Piedigrossi, D.; Van Dijk, M.

    2015-07-01

    The Time Of internally Reflected Cherenkov light (TORCH) detector is under development. Charged particle tracks passing through a 1 cm plate of quartz will generate the Cherenkov photons, and their arrival will be timed by an array of micro-channel plate photon detectors. As part of the TORCH R&D studies, commercial and custom-made micro-channel plate detectors are being characterized. The final photon detectors for this application are being produced in a three-phase program in collaboration with industry. Custom-made single-channel devices with extended lifetime have been manufactured and their performance is being systematically investigated in the laboratory. Optical studies for the preparation of beam and laboratory tests of a TORCH prototype are also underway.

  12. The experimental cascade curves of EAS at E sub 0 10(17) eV obtained by the method of detection of Cherenkov pulse shape

    NASA Technical Reports Server (NTRS)

    Fomin, Y. A.; Kalmykov, G. B.; Khristiansen, M. V.; Motova, M. V.; Nechin, Y. A.; Prosin, V. V.; Zhukov, V. Y.; Efimov, N. N.; Grigoriev, V. M.; Nikiforova, E. S.

    1985-01-01

    The individual cascade curves of EAS with E sub 0 10 to the 17th power eV/I to 3/ were studied by detection of EAS Cherenkov light pulses. The scintillators located at the center of the Yakutsk EAS array within a 500-m radius circle were used to select the showers and to determine the main EAS parameters. The individual cascade curves N(t) were obtained using the EAS Cherenkov light pulses satisfying the following requirements: (1) the signal-to-noise ratio fm/delta sub n 15, (2) the EAS axis-detector distance tau sub 350 m, (3) the zenith angle theta 30 deg, (4) the probability for EAS to be detected by scintillators W 0.8. Condition (1) arises from the desire to reduce the amplitude distortion of Cherenkov pulses due to noise and determines the range of EAS sizes, N(t). The resolution times of the Cherenkov pulse shape detectors are tau sub 0 approx. 23 ns which results in distortion of a pulse during the process of the detection. The distortion of pulses due to the finiteness of tau sub 0 value was estimated. It is shown that the rise time of pulse becomes greater as tau sub 0.5/tau sub 0 ratio decreases.

  13. Conceptual history of the Vavilov-Cherenkov radiation

    SciTech Connect

    Frank, I.M.

    1984-05-01

    The evolution of ideas on the nature of the Vavilov-Cherenkov radiation is discussed. The period between Vavilov's ideas, advanced in 1934, and the formulation of a quantitative theory of the phenomenon in 1937 is surveyed.

  14. Gain and efficiency of a stimulated Cherenkov optical Klystron

    SciTech Connect

    Wang, D.Y.; Fauchet, A.; Pantell, R.H.; Piestrup, M.A.

    1983-03-01

    A scheme for building an optical klystron oscillator based on the stimulated Cherenkov interaction between light and relativistic electrons is presented. The gain and efficiency of such a device as a function of wavelength is discussed.

  15. Constraint on ghost-free bigravity from gravitational Cherenkov radiation

    NASA Astrophysics Data System (ADS)

    Kimura, Rampei; Tanaka, Takahiro; Yamamoto, Kazuhiro; Yamashita, Yasuho

    2016-09-01

    We investigate gravitational Cherenkov radiation in a healthy branch of background solutions in the ghost-free bigravity model. In this model, because of the modification of dispersion relations, each polarization mode can possess subluminal phase velocities, and the gravitational Cherenkov radiation could be potentially emitted from a relativistic particle. In the present paper, we derive conditions for the process of the gravitational Cherenkov radiation to occur and estimate the energy emission rate for each polarization mode. We found that the gravitational Cherenkov radiation emitted even from an ultrahigh energy cosmic ray is sufficiently suppressed for the graviton's effective mass less than 100 eV, and the bigravity model with dark matter coupled to the hidden metric is therefore consistent with observations of high energy cosmic rays.

  16. Observation of seasonal variation of atmospheric multiple-muon events in the MINOS Near and Far Detectors

    NASA Astrophysics Data System (ADS)

    Adamson, P.; Anghel, I.; Aurisano, A.; Barr, G.; Bishai, M.; Blake, A.; Bock, G. J.; Bogert, D.; Cao, S. V.; Castromonte, C. M.; Childress, S.; Coelho, J. A. B.; Corwin, L.; Cronin-Hennessy, D.; de Jong, J. K.; Devan, A. V.; Devenish, N. E.; Diwan, M. V.; Escobar, C. O.; Evans, J. J.; Falk, E.; Feldman, G. J.; Frohne, M. V.; Gallagher, H. R.; Gomes, R. A.; Goodman, M. C.; Gouffon, P.; Graf, N.; Gran, R.; Grzelak, K.; Habig, A.; Hahn, S. R.; Hartnell, J.; Hatcher, R.; Holin, A.; Huang, J.; Hylen, J.; Irwin, G. M.; Isvan, Z.; James, C.; Jensen, D.; Kafka, T.; Kasahara, S. M. S.; Koizumi, G.; Kordosky, M.; Kreymer, A.; Lang, K.; Ling, J.; Litchfield, P. J.; Lucas, P.; Mann, W. A.; Marshak, M. L.; Mayer, N.; McGivern, C.; Medeiros, M. M.; Mehdiyev, R.; Meier, J. R.; Messier, M. D.; Miller, W. H.; Mishra, S. R.; Moed Sher, S.; Moore, C. D.; Mualem, L.; Musser, J.; Naples, D.; Nelson, J. K.; Newman, H. B.; Nichol, R. J.; Nowak, J. A.; O'Connor, J.; Orchanian, M.; Osprey, S.; Pahlka, R. B.; Paley, J.; Patterson, R. B.; Pawloski, G.; Perch, A.; Phan-Budd, S.; Plunkett, R. K.; Poonthottathil, N.; Qiu, X.; Radovic, A.; Rebel, B.; Rosenfeld, C.; Rubin, H. A.; Sanchez, M. C.; Schneps, J.; Schreckenberger, A.; Schreiner, P.; Sharma, R.; Sousa, A.; Tagg, N.; Talaga, R. L.; Thomas, J.; Thomson, M. A.; Tian, X.; Timmons, A.; Tognini, S. C.; Toner, R.; Torretta, D.; Urheim, J.; Vahle, P.; Viren, B.; Weber, A.; Webb, R. C.; White, C.; Whitehead, L.; Whitehead, L. H.; Wojcicki, S. G.; Zwaska, R.; Minos Collaboration

    2015-06-01

    We report the first observation of seasonal modulations in the rates of cosmic ray multiple-muon events at two underground sites, the MINOS Near Detector with an overburden of 225 mwe, and the MINOS Far Detector site at 2100 mwe. At the deeper site, multiple-muon events with muons separated by more than 8 m exhibit a seasonal rate that peaks during the summer, similar to that of single-muon events. In contrast and unexpectedly, the rate of multiple-muon events with muons separated by less than 5-8 m, and the rate of multiple-muon events in the smaller, shallower Near Detector, exhibit a seasonal rate modulation that peaks in the winter.

  17. Observation of seasonal variation of atmospheric multiple-muon events in the MINOS Near and Far Detectors

    SciTech Connect

    Adamson, P.; Bishai, M.; Diwan, M. V.; Isvan, Z.; Ling, J.; Viren, B.

    2015-06-09

    We report the first observation of seasonal modulations in the rates of cosmic ray multiple-muon events at two underground sites, the MINOS Near Detector with an overburden of 225 mwe, and the MINOS Far Detector site at 2100 mwe. At the deeper site, multiple-muon events with muons separated by more than 8 m exhibit a seasonal rate that peaks during the summer, similar to that of single-muon events. Conversely, the rate of multiple-muon events with muons separated by less than 5–8 m, and the rate of multiple-muon events in the smaller, shallower Near Detector, exhibit a seasonal rate modulation that peaks in the winter.

  18. Observation of seasonal variation of atmospheric multiple-muon events in the MINOS Near and Far Detectors

    DOE PAGESBeta

    Adamson, P.; Bishai, M.; Diwan, M. V.; Isvan, Z.; Ling, J.; Viren, B.

    2015-06-09

    We report the first observation of seasonal modulations in the rates of cosmic ray multiple-muon events at two underground sites, the MINOS Near Detector with an overburden of 225 mwe, and the MINOS Far Detector site at 2100 mwe. At the deeper site, multiple-muon events with muons separated by more than 8 m exhibit a seasonal rate that peaks during the summer, similar to that of single-muon events. Conversely, the rate of multiple-muon events with muons separated by less than 5–8 m, and the rate of multiple-muon events in the smaller, shallower Near Detector, exhibit a seasonal rate modulation thatmore » peaks in the winter.« less

  19. Observation of seasonal variation of atmospheric multiple-muon events in the MINOS near and far detectors

    SciTech Connect

    Adamson, P.

    2015-06-09

    We report the first observation of seasonal modulations in the rates of cosmic ray multiple-muon events at two underground sites, the MINOS Near Detector with an overburden of 225 mwe, and the MINOS Far Detector site at 2100 mwe. Thus, at the deeper site, multiple-muon events with muons separated by more than 8 m exhibit a seasonal rate that peaks during the summer, similar to that of single-muon events. In contrast and unexpectedly, the rate of multiple-muon events with muons separated by less than 5–8 m, and the rate of multiple-muon events in the smaller, shallower Near Detector, exhibit a seasonal rate modulation that peaks in the winter.

  20. RICH Detector for Jefferson Labs CLAS12

    NASA Astrophysics Data System (ADS)

    Trotta, Richard; Torisky, Ben; Benmokhtar, Fatiha

    2015-10-01

    Jefferson Lab (Jlab) is performing a large-scale upgrade to its Continuous Electron Beam Accelerator Facility (CEBAF) up to 12GeV beams. The Large Acceptance Spectrometer (CLAS12) in Hall B is being upgraded and a new hybrid Ring Imaging Cherenkov (RICH) detector is being developed to provide better kaon - pion separation throughout the 3 to 8 GeV/c momentum range. This detector will be used for a variety of Semi-Inclusive Deep Inelastic Scattering experiments. Cherenkov light can be accurately detected by a large array of sophisticated Multi-Anode Photomultiplier Tubes (MA-PMT) and heavier particles, like kaons, will span the inner radii. We are presenting our work on the creation of the RICH's geometry within the CLAS12 java framework. This development is crucial for future calibration, reconstructions and analysis of the detector.

  1. Energy calibration of Cherenkov Telescopes using GLAST data

    SciTech Connect

    Bastieri, D.; Busetto, G.; Piano, G.; Rando, R.; Saggion, A.; De Angelis, A.; Longo, F.

    2007-07-12

    We discuss the possibility of using the observations by GLAST of steady gamma sources, as the Crab Nebula and some selected AGNs, to calibrate the Imaging Air Cherenkov Telescopes (IACT) and improve their energy resolution, in particular. We show that at around 100 GeV, exploiting the features in the spectrum of the Crab Nebula, the absolute energy calibration uncertainty of Cherenkov telescopes can be reduced to < 10%.

  2. Electron Beam Diagnostics using Coherent Cherenkov Radiation in Aerogel

    SciTech Connect

    Tikhoplav, R.; Knyazik, A.; Rosenzweig, J. B.; Ruelas, M.

    2009-01-22

    The use of coherent Cherenkov radiation as a diagnostic tool for longitudinal distribution of an electron beam is studied in this paper. Coherent Cherenkov radiation is produced in an aerogel with an index of refraction close to unity. An aerogel spectral properties are experimentally studied and analyzed. This method will be employed for the helical IFEL bunching experiment at Neptune linear accelerator facility at UCLA.

  3. Electron Beam Diagnostics using Coherent Cherenkov Radiation in Aerogel

    NASA Astrophysics Data System (ADS)

    Tikhoplav, R.; Knyazik, A.; Rosenzweig, J. B.; Ruelas, M.

    2009-01-01

    The use of coherent Cherenkov radiation as a diagnostic tool for longitudinal distribution of an electron beam is studied in this paper. Coherent Cherenkov radiation is produced in an aerogel with an index of refraction close to unity. An aerogel spectral properties are experimentally studied and analyzed. This method will be employed for the helical IFEL bunching experiment at Neptune linear accelerator facility at UCLA.

  4. The design and performance of a prototype water Cherenkov optical time-projection chamber

    NASA Astrophysics Data System (ADS)

    Oberla, Eric; Frisch, Henry J.

    2016-04-01

    A first experimental test of tracking relativistic charged particles by 'drifting' Cherenkov photons in a water-based optical time-projection chamber (OTPC) has been performed at the Fermilab Test Beam Facility. The prototype OTPC detector consists of a 77 cm long, 28 cm diameter, 40 kg cylindrical water mass instrumented with a combination of commercial 5.1 × 5.1cm2 micro-channel plate photo-multipliers (MCP-PMT) and 6.7 × 6.7cm2 mirrors. Five MCP-PMTs are installed in two columns along the OTPC cylinder in a small-angle stereo configuration. A mirror is mounted opposite each MCP-PMT on the inner surface of the detector cylinder, effectively increasing the photo-detection efficiency and providing a time-resolved image of the Cherenkov light on the opposing wall. Each MCP-PMT is coupled to an anode readout consisting of thirty 50 Ω microstrips. A 180-channel data acquisition system digitizes the MCP-PMT signals on one end of the microstrips using the PSEC4 waveform sampling-and-digitizing chip operating at a sampling rate of 10.24 Gigasamples-per-second. The single-ended microstrip readout determines the time and position of a photon arrival at the face of the MCP-PMT by recording both the direct signal and the pulse reflected from the unterminated far end of the strip. The detector was installed on the Fermilab MCenter secondary beam-line behind a steel absorber where the primary flux is multi-GeV muons. Approximately 80 Cherenkov photons are detected for a through-going muon track in a total event duration of ~2 ns. By measuring the time-of-arrival and the position of individual photons at the surface of the detector to ≤ 100 ps and a few mm, respectively, we have measured a spatial resolution of ~15 mm for each MCP-PMT track segment, and, from linear fits over the entire track length of ~40 cm, an angular resolution on the track direction of ~60 mrad.

  5. Orthogonal Cherenkov sound in spin-orbit coupled systems

    NASA Astrophysics Data System (ADS)

    Smirnov, Sergey

    2015-06-01

    Conventionally the Cherenkov sound is governed by orbital degrees of freedom and is excited by supersonic particles. Additionally, it usually has a forward nature with a conic geometry known as the Cherenkov cone whose axis is oriented along the supersonic particle motion. Here we predict Cherenkov sound of a unique nature entirely resulting from the electronic spin degree of freedom and demonstrate a fundamentally distinct Cherenkov effect originating from essentially subsonic electrons in two-dimensional gases with both Bychkov-Rashba and Dresselhaus spin-orbit interactions. Specifically, we show that the axis of the conventional forward Cherenkov cone gets a nontrivial quarter-turn and at the same time the sound distribution strongly localizes around this rotated axis being now orthogonal to the subsonic particle motion. Apart from its fundamentally appealing nature, the orthogonal Cherenkov sound could have applications in planar semiconductor technology combining spin and acoustic phenomena to develop, e.g., acoustic amplifiers or sound sources with a flexible spin dependent orientation of the sound propagation.

  6. Orthogonal Cherenkov sound in spin-orbit coupled systems

    PubMed Central

    Smirnov, Sergey

    2015-01-01

    Conventionally the Cherenkov sound is governed by orbital degrees of freedom and is excited by supersonic particles. Additionally, it usually has a forward nature with a conic geometry known as the Cherenkov cone whose axis is oriented along the supersonic particle motion. Here we predict Cherenkov sound of a unique nature entirely resulting from the electronic spin degree of freedom and demonstrate a fundamentally distinct Cherenkov effect originating from essentially subsonic electrons in two-dimensional gases with both Bychkov-Rashba and Dresselhaus spin-orbit interactions. Specifically, we show that the axis of the conventional forward Cherenkov cone gets a nontrivial quarter-turn and at the same time the sound distribution strongly localizes around this rotated axis being now orthogonal to the subsonic particle motion. Apart from its fundamentally appealing nature, the orthogonal Cherenkov sound could have applications in planar semiconductor technology combining spin and acoustic phenomena to develop, e.g., acoustic amplifiers or sound sources with a flexible spin dependent orientation of the sound propagation. PMID:26083355

  7. A simulation study investigating a Cherenkov material for use with the prompt gamma range verification in proton therapy.

    PubMed

    Lau, Andy; Ahmad, Salahuddin; Chen, Yong

    2016-05-01

    In vivo range verification methods will reveal information about the penetration depth into a patient for an incident proton beam. The prompt gamma (PG) method is a promising in vivo technique that has been shown to yield this range information by measuring the escaping MeV photons given a suitable detector system. The majority of current simulations investigating PG detectors utilize common scintillating materials ideal for photons within a low neutron background radiation field using complex geometries or novel designs. In this work we simulate a minimal detector system using a material ideal for MeV photon detection in the presence of a significant neutron field based on the Cherenkov phenomenon. The response of this selected material was quantified for the escaping particles commonly found in proton therapy applications and the feasibility of using the PG technique for this detector material was studied. Our simulations found that the majority of the range information can be determined by detecting photons emitted with a timing window less than ∼50 ns after the interaction of the proton beam with the water phantom and with an energy threshold focusing on the energy range of the de-excitation of 16O photons (∼6 MeV). The Cherenkov material investigated is able to collect these photons and estimate the range with timescales on the order of tens of nanoseconds as well as greatly suppress the signal due to neutron. PMID:27163377

  8. Six-circle diffractometer with atmosphere- and temperature-controlled sample stage and area and line detectors for use in the G2 experimental station at CHESS

    SciTech Connect

    Nowak, D. E.; Blasini, D. R.; Vodnick, A. M.; Blank, B.; Tate, M. W.; Deyhim, A.; Smilgies, D.-M.; Abruna, H.; Gruner, S. M.; Baker, S. P.

    2006-11-15

    A new diffractometer system was designed and built for the G2 experimental station at the Cornell High Energy Synchrotron Source (CHESS). A six-circle {kappa} goniometer, which provides better access to reciprocal space compared to Eulerian cradles, was chosen primarily to perform large angle Bragg diffraction on samples with preferred crystallographic orientations, and can access both horizontal and vertical diffraction planes. A new atmosphere- and temperature-controlled sample stage was designed for thin film thermomechanical experiments. The stage can be operated in ultrahigh vacuum and uses a Be dome x-ray window to provide access to all scattering vectors above a sample's horizon. A novel design minimizes sample displacements during thermal cycling to less than 160 {mu}m over 900 deg. C and the stage is motorized for easy height adjustments, which can be used to compensate for displacements from thermal expansion. A new area detector was built and a new line detector was purchased. Both detectors cover a large region in reciprocal space, providing the ability to measure time-resolved phenomena. A detailed description of the design and technical characteristics is given. Some capabilities of the diffractometer system are illustrated by a strain analysis on a thin metal film and characterization of organic thin films with grazing incidence diffraction. The G2 experimental station, as part of CHESS, is a national user facility and is available to external users by application.

  9. The Energy Spectrum of Atmospheric Neutrinos between 2 and 200 TeV with the AMANDA-II Detector

    SciTech Connect

    IceCube Collaboration; Abbasi, R.

    2010-05-11

    The muon and anti-muon neutrino energy spectrum is determined from 2000-2003 AMANDA telescope data using regularised unfolding. This is the first measurement of atmospheric neutrinos in the energy range 2-200 TeV. The result is compared to different atmospheric neutrino models and it is compatible with the atmospheric neutrinos from pion and kaon decays. No significant contribution from charm hadron decays or extraterrestrial neutrinos is detected. The capabilities to improve the measurement of the neutrino spectrum with the successor experiment IceCube are discussed.

  10. Cherenkov imaging and biochemical sensing in vivo during radiation therapy

    NASA Astrophysics Data System (ADS)

    Zhang, Rongxiao

    While Cherenkov emission was discovered more than eighty years ago, the potential applications of imaging this during radiation therapy have just recently been explored. With approximately half of all cancer patients being treated by radiation at some point during their cancer management, there is a constant challenge to ensure optimal treatment efficiency is achieved with maximal tumor to normal tissue therapeutic ratio. To achieve this, the treatment process as well as biological information affecting the treatment should ideally be effective and directly derived from the delivery of radiation to the patient. The value of Cherenkov emission imaging was examined here, primarily for visualization of treatment monitoring and then secondarily for Cherenkov-excited luminescence for tissue biochemical sensing within tissue. Through synchronized gating to the short radiation pulses of a linear accelerator (200Hz & 3 micros pulses), and applying a gated intensified camera for imaging, the Cherenkov radiation can be captured near video frame rates (30 frame per sec) with dim ambient room lighting. This procedure, sometimes termed Cherenkoscopy, is readily visualized without affecting the normal process of external beam radiation therapy. With simulation, phantoms and clinical trial data, each application of Cherenkoscopy was examined: i) for treatment monitoring, ii) for patient position monitoring and motion tracking, and iii) for superficial dose imaging. The temporal dynamics of delivered radiation fields can easily be directly imaged on the patient's surface. Image registration and edge detection of Cherenkov images were used to verify patient positioning during treatment. Inter-fraction setup accuracy and intra-fraction patient motion was detectable to better than 1 mm accuracy. Cherenkov emission in tissue opens up a new field of biochemical sensing within the tissue environment, using luminescent agents which can be activated by this light. In the first study of

  11. Expected performance of the ASTRI mini-array in the framework of the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Di Pierro, F.; Bigongiari, C.; Stamerra, A.; Vallania, P.; ASTRI Collaboration; CTA Consortium, the

    2016-05-01

    The Cherenkov Telescope Array (CTA) Observatory is a world-wide project for the ground-based study of the sources of the highest energy photons. By adopting telescopes of three different size categories it will cover the wide energy range from tens of GeV up to hundreds of TeV, limited only by the source physical properties and the gamma absorption by the extragalactic background light. The full sky coverage will be assured by two arrays, one in each hemisphere. An array of small size telescopes (SSTs), covering the highest energy region (3-100 TeV), the region most flux limited for current imaging atmospheric Cherenkov telescopes, is planned to be deployed at the southern CTA site in the first phase of the CTA project. The ASTRI collaboration has developed a prototype of a dual mirror SST equipped with a SiPM-based focal plane (ASTRI SST-2M) and has proposed to install a mini-array of nine of such telescopes at the CTA southern site (the ASTRI mini-array). In order to study the expected performance and the scientific capabilities of different telescope configurations, full Monte Carlo (MC) simulations of the shower development in the atmosphere for both gammas and hadronic background have been performed, followed by detailed simulations of the telescopes. In this work the expected performance of the ASTRI mini-array in terms of sensitivity, angular and energy resolution are presented and discussed.

  12. Status of the photomultiplier-based FlashCam camera for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Pühlhofer, G.; Bauer, C.; Eisenkolb, F.; Florin, D.; Föhr, C.; Gadola, A.; Garrecht, F.; Hermann, G.; Jung, I.; Kalekin, O.; Kalkuhl, C.; Kasperek, J.; Kihm, T.; Koziol, J.; Lahmann, R.; Manalaysay, A.; Marszalek, A.; Rajda, P. J.; Reimer, O.; Romaszkan, W.; Rupinski, M.; Schanz, T.; Schwab, T.; Steiner, S.; Straumann, U.; Tenzer, C.; Vollhardt, A.; Weitzel, Q.; Winiarski, K.; Zietara, K.

    2014-07-01

    The FlashCam project is preparing a camera prototype around a fully digital FADC-based readout system, for the medium sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The FlashCam design is the first fully digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for digitization and triggering, and a high performance camera server as back end. It provides the option to easily implement different types of trigger algorithms as well as digitization and readout scenarios using identical hardware, by simply changing the firmware on the FPGAs. The readout of the front end modules into the camera server is Ethernet-based using standard Ethernet switches and a custom, raw Ethernet protocol. In the current implementation of the system, data transfer and back end processing rates of 3.8 GB/s and 2.4 GB/s have been achieved, respectively. Together with the dead-time-free front end event buffering on the FPGAs, this permits the cameras to operate at trigger rates of up to several ten kHz. In the horizontal architecture of FlashCam, the photon detector plane (PDP), consisting of photon detectors, preamplifiers, high voltage-, control-, and monitoring systems, is a self-contained unit, mechanically detached from the front end modules. It interfaces to the digital readout system via analogue signal transmission. The horizontal integration of FlashCam is expected not only to be more cost efficient, it also allows PDPs with different types of photon detectors to be adapted to the FlashCam readout system. By now, a 144-pixel mini-camera" setup, fully equipped with photomultipliers, PDP electronics, and digitization/ trigger electronics, has been realized and extensively tested. Preparations for a full-scale, 1764 pixel camera mechanics and a cooling system are ongoing. The paper describes the status of the project.

  13. Construction of prototype two-mirror Schwartzchild-Couder Imaging Air Cherenkov Telescope (IACT) for VHE gamma-ray astronomy

    NASA Astrophysics Data System (ADS)

    Kieda, David; CTA-US Collaboration Collaboration

    2016-03-01

    Next generation ground-based VHE gamma-ray observatories such as the Cherenkov Telescope Array (CTA) will employ an array of different sized IACTs distributed across square kilometer areas. During 2015-2016, the CTA-US collaboration is constructing a prototype 9.6 m primary diameter Schwartzchild-Couder IACT (SCT) at the FL Whipple Observatory, Amado, AZ USA. The two-mirror SCT design provides 8 degree field of view with 0.067 degree pixel size. The SCT uses a high resolution (11,328 pixel) Silicon PhotoMultiplier (SiPM) camera to record atmospheric Cherenkov light images generated by gamma-ray and cosmic ray primaries. Incorporation of SCT telescopes into a CTA-type observatory can provide superior angular resolution (30 % improvement) and point source sensitivity (30-50 %). In this talk, I will describe the capabilities of the SCT telescope, and the construction and commissioning of the prototype SCT telescope during 2016.

  14. An engineering array for the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory

    NASA Astrophysics Data System (ADS)

    Longo, Megan; Mostafa, Miguel

    2012-03-01

    The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is currently being deployed at 4100 m in Sierra Negra, Mexico. The HAWC observatory will have 300 Water Cherenkov Detectors (WCDs). Each WCD will be instrumented with 4 upward facing baffled photo multiplier tubes (PMTs) anchored to the bottom of a 5 m deep by 7.3 m diameter steel container with a multilayer hermetic plastic bag containing 200,000 liters of purified water. An engineering array of 6 WCDs was deployed in Summer 2011 at the HAWC site and has been operational since then. This array serves to validate the design and construction methods for the HAWC observatory. It has also been collecting data which allows for the development of data collection and analysis tools. Here we will describe the deployment of the engineering array, the lessons learned from this experience and the implications for HAWC, as well as give an introduction into data collection and initial analysis being done, which will be presented jointly.

  15. Design and Experimental Demonstration of Cherenkov Radiation Source Based on Metallic Photonic Crystal Slow Wave Structure

    NASA Astrophysics Data System (ADS)

    Fu, Tao; Yang, Zi-Qiang; Ouyang, Zheng-Biao

    2016-11-01

    This paper presents a kind of Cherenkov radiation source based on metallic photonic crystal (MPC) slow-wave structure (SWS) cavity. The Cherenkov source designed by linear theory works at 34.7 GHz when the cathode voltage is 550 kV. The three-dimensional particle-in-cell (PIC) simulation of the SWS shows the operating frequency of 35.56 GHz with a single TM01 mode is basically consistent with the theoretically one under the same parameters. An experiment was implemented to testify the results of theory and PIC simulation. The experimental system includes a cathode emitting unit, the SWS, a magnetic system, an output antenna, and detectors. Experimental results show that the operating frequency through detecting the retarded time of wave propagation in waveguides is around 35.5 GHz with a single TM01 mode and an output power reaching 54 MW. It indicates that the MPC structure can reduce mode competition. The purpose of the paper is to show in theory and in preliminary experiment that a SWS with PBG can produce microwaves in TM01 mode. But it still provides a good experimental and theoretical foundation for designing high-power microwave devices.

  16. Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF.

    PubMed

    Herrmann, Hans W; Mack, Joseph M; Young, Carlton S; Malone, Robert M; Stoeffl, Wolfgang; Horsfield, Colin J

    2008-10-01

    Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from gamma rays to relativistic electrons to UV/visible Cherenkov radiation. PMID:19044512

  17. Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF.

    PubMed

    Herrmann, Hans W; Mack, Joseph M; Young, Carlton S; Malone, Robert M; Stoeffl, Wolfgang; Horsfield, Colin J

    2008-10-01

    Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from gamma rays to relativistic electrons to UV/visible Cherenkov radiation.

  18. Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF

    SciTech Connect

    Herrmann, Hans W.; Mack, Joseph M.; Young, Carlton S.; Malone, Robert M.; Stoeffl, Wolfgang; Horsfield, Colin J.

    2008-10-15

    Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from {gamma} rays to relativistic electrons to UV/visible Cherenkov radiation.

  19. FastDIRC: a fast Monte Carlo and reconstruction algorithm for DIRC detectors

    NASA Astrophysics Data System (ADS)

    Hardin, J.; Williams, M.

    2016-10-01

    FastDIRC is a novel fast Monte Carlo and reconstruction algorithm for DIRC detectors. A DIRC employs rectangular fused-silica bars both as Cherenkov radiators and as light guides. Cherenkov-photon imaging and time-of-propagation information are utilized by a DIRC to identify charged particles. GEANT4-based DIRC Monte Carlo simulations are extremely CPU intensive. The FastDIRC algorithm permits fully simulating a DIRC detector more than 10 000 times faster than using GEANT4. This facilitates designing a DIRC-reconstruction algorithm that improves the Cherenkov-angle resolution of a DIRC detector by ≈ 30% compared to existing algorithms. FastDIRC also greatly reduces the time required to study competing DIRC-detector designs.

  20. Comparison of Cherenkov excited fluorescence and phosphorescence molecular sensing from tissue with external beam irradiation.

    PubMed

    Lin, Huiyun; Zhang, Rongxiao; Gunn, Jason R; Esipova, Tatiana V; Vinogradov, Sergei; Gladstone, David J; Jarvis, Lesley A; Pogue, Brian W

    2016-05-21

    Ionizing radiation delivered by a medical linear accelerator (LINAC) generates Cherenkov emission within the treated tissue. A fraction of this light, in the 600-900 nm wavelength region, propagates through centimeters of tissue and can be used to excite optical probes in vivo, enabling molecular sensing of tissue analytes. The success of isolating the emission signal from this Cherenkov excitation background is dependent on key factors such as: (i) the Stokes shift of the probe spectra; (ii) the excited state lifetime; (iii) the probe concentration; (iv) the depth below the tissue surface; and (v) the radiation dose used. Previous studies have exclusively focused on imaging phosphorescent dyes, rather than fluorescent dyes. However there are only a few biologically important phosphorescent dyes and yet in comparison there are thousands of biologically relevant fluorescent dyes. So in this study the focus was a study of efficacy of Cherenkov-excited luminescence using fluorescent commercial near-infrared probes, IRDye 680RD, IRDye 700DX, and IRDye 800CW, and comparing them to the well characterized phosphorescent probe Oxyphor PtG4, an oxygen sensitive dye. Each probe was excited by Cherenkov light from a 6 MV external radiation beam, and measured in continuous wave or time-gated modes. The detection was performed by spectrally resolving the luminescence signals, and measuring them with spectrometer-based separation on an ICCD detector. The results demonstrate that IRDye 700DX and PtG4 allowed for the maximal signal to noise ratio. In the case of the phosphorescent probe, PtG4, with emission decays on the microsecond (μs) time scale, time-gated acquisition was possible, and it allowed for higher efficacy in terms of the probe concentration and detection depth. Phantoms containing the probe at 5 mm depth could be detected at concentrations down to the nanoMolar range, and at depths into the tissue simulating phantom near 3 cm. In vivo studies showed that 5

  1. Comparison of Cherenkov excited fluorescence and phosphorescence molecular sensing from tissue with external beam irradiation.

    PubMed

    Lin, Huiyun; Zhang, Rongxiao; Gunn, Jason R; Esipova, Tatiana V; Vinogradov, Sergei; Gladstone, David J; Jarvis, Lesley A; Pogue, Brian W

    2016-05-21

    Ionizing radiation delivered by a medical linear accelerator (LINAC) generates Cherenkov emission within the treated tissue. A fraction of this light, in the 600-900 nm wavelength region, propagates through centimeters of tissue and can be used to excite optical probes in vivo, enabling molecular sensing of tissue analytes. The success of isolating the emission signal from this Cherenkov excitation background is dependent on key factors such as: (i) the Stokes shift of the probe spectra; (ii) the excited state lifetime; (iii) the probe concentration; (iv) the depth below the tissue surface; and (v) the radiation dose used. Previous studies have exclusively focused on imaging phosphorescent dyes, rather than fluorescent dyes. However there are only a few biologically important phosphorescent dyes and yet in comparison there are thousands of biologically relevant fluorescent dyes. So in this study the focus was a study of efficacy of Cherenkov-excited luminescence using fluorescent commercial near-infrared probes, IRDye 680RD, IRDye 700DX, and IRDye 800CW, and comparing them to the well characterized phosphorescent probe Oxyphor PtG4, an oxygen sensitive dye. Each probe was excited by Cherenkov light from a 6 MV external radiation beam, and measured in continuous wave or time-gated modes. The detection was performed by spectrally resolving the luminescence signals, and measuring them with spectrometer-based separation on an ICCD detector. The results demonstrate that IRDye 700DX and PtG4 allowed for the maximal signal to noise ratio. In the case of the phosphorescent probe, PtG4, with emission decays on the microsecond (μs) time scale, time-gated acquisition was possible, and it allowed for higher efficacy in terms of the probe concentration and detection depth. Phantoms containing the probe at 5 mm depth could be detected at concentrations down to the nanoMolar range, and at depths into the tissue simulating phantom near 3 cm. In vivo studies showed that 5

  2. Comparison of Cherenkov excited fluorescence and phosphorescence molecular sensing from tissue with external beam irradiation

    NASA Astrophysics Data System (ADS)

    Lin, Huiyun; Zhang, Rongxiao; Gunn, Jason R.; Esipova, Tatiana V.; Vinogradov, Sergei; Gladstone, David J.; Jarvis, Lesley A.; Pogue, Brian W.

    2016-05-01

    Ionizing radiation delivered by a medical linear accelerator (LINAC) generates Cherenkov emission within the treated tissue. A fraction of this light, in the 600-900 nm wavelength region, propagates through centimeters of tissue and can be used to excite optical probes in vivo, enabling molecular sensing of tissue analytes. The success of isolating the emission signal from this Cherenkov excitation background is dependent on key factors such as: (i) the Stokes shift of the probe spectra; (ii) the excited state lifetime; (iii) the probe concentration; (iv) the depth below the tissue surface; and (v) the radiation dose used. Previous studies have exclusively focused on imaging phosphorescent dyes, rather than fluorescent dyes. However there are only a few biologically important phosphorescent dyes and yet in comparison there are thousands of biologically relevant fluorescent dyes. So in this study the focus was a study of efficacy of Cherenkov-excited luminescence using fluorescent commercial near-infrared probes, IRDye 680RD, IRDye 700DX, and IRDye 800CW, and comparing them to the well characterized phosphorescent probe Oxyphor PtG4, an oxygen sensitive dye. Each probe was excited by Cherenkov light from a 6 MV external radiation beam, and measured in continuous wave or time-gated modes. The detection was performed by spectrally resolving the luminescence signals, and measuring them with spectrometer-based separation on an ICCD detector. The results demonstrate that IRDye 700DX and PtG4 allowed for the maximal signal to noise ratio. In the case of the phosphorescent probe, PtG4, with emission decays on the microsecond (μs) time scale, time-gated acquisition was possible, and it allowed for higher efficacy in terms of the probe concentration and detection depth. Phantoms containing the probe at 5 mm depth could be detected at concentrations down to the nanoMolar range, and at depths into the tissue simulating phantom near 3 cm. In vivo studies showed that 5

  3. Improved Detection of Cherenkov Radiation using Wavelength-Shifting Paints

    NASA Astrophysics Data System (ADS)

    Schmookler, Barak; Ou, Longwu

    2014-03-01

    Photomultiplier Tubes (PMTs) are often used to detect Cherenkov radiation in accelerator-based physics experiments. Since the Cherenkov spectrum is inversely proportional to the square of the photon's wavelength, PMTs with relatively good quantum efficiencies in the ultraviolet region can produce on average a higher number of photoelectrons. The application of certain paints, which absorb light at ultraviolet wavelengths and emit in the visible spectrum, to the surface of some PMTs allows for better sampling of the Cherenkov spectrum. The effects of various wavelength-shifting (WLS) paints designed by Eljen Technologies were tested on ET Enterprises, Model: 9390KB PMTs. Using a 106Ru β-source, Cherenkov light was produced in disks of fused silica. The charge spectrums of the PMTs were measured before and after application of the paint. The average number of photoelectrons produced from the Cherenkov radiation could be determined by knowing the value of the single-photoelectron peak and the mean of the charge spectrum. Four paints were tested, and the gain in the number photoelectrons produced varied from 10-35% for the different paints. Work Conducted at Thomas Jefferson National Accelerator Facility.

  4. Beam Test of a Time-of-Flight Detector Prototype

    SciTech Connect

    Va'vra, J.; Leith, D.W.G.S.; Ratcliff, B.; Ramberg, E.; Albrow, M.; Ronzhin, A.; Ertley, C.; Natoli, T.; May, E.; Byrum, K.; /Argonne

    2009-04-01

    We report on results of a Time-of-Flight, TOF, counter prototype in beam tests at SLAC and Fermilab. Using two identical 64-pixel Photonis Microchannel Plate Photomultipliers, MCP-PMTs, to provide start and stop signals, each having a 1 cm-long quartz Cherenkov radiator, we have achieved a timing resolution of {sigma}{sub Single{_}detector} {approx} 14 ps.

  5. News and Views: SCUBA-2 shows its mettle; Exoplanet hit by stellar flare - loses atmosphere; Supercomputing to serve weather forecasting; South Pole detectors will predict solar proton events

    NASA Astrophysics Data System (ADS)

    2012-08-01

    A dramatic demonstration of the effects of a flare from a star on the atmosphere of a closely orbiting gas giant exoplanet has come from combining data from the Hubble Space Telescope and NASA'a Swift gamma-ray observatory. The Science and Technology Facilities Council (STFC), the Met Office and the Natural Environment Research Council (NERC) are together designing and building a next-generation weather forecasting model that will exploit ultra-fast supercomputers and boost the effectiveness of forecasts. The goal is to save money - and lives. Energetic particles from the Sun are a known hazard to astronauts and passengers and crew of high-altitude aircraft on polar flightpaths. Now researchers plan to predict such events using neutron detectors at Earth's South Pole.

  6. Sensitivity of the High Altitude Water Cherenkov Experiment to observe Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    González, M. M.

    Ground based telescopes have marginally observed very high energy emission (>100GeV) from gamma-ray bursts(GRB). For instance, Milagrito observed GRB970417a with a significance of 3.7 sigmas over the background. Milagro have not yet observed TeV emission from a GRB with its triggered and untriggered searches or GeV emission with a triggered search using its scalers. These results suggest the need of new observatories with higher sensitivity to transient sources. The HAWC (High Altitute Water Cherenkov) observatory is proposed as a combination of the Milagro tecnology with a very high altitude (>4000m over see level) site. The expected HAWC sensitivity for GRBs is at least >10 times the Milagro sensitivity. In this work HAWC sensitivity for GRBs is discussed for different detector configurations such as altitude, distance between PMTs, depth under water of PMTs, number of PMTs required for a trigger, etc.

  7. Strangeonium spectroscopy at 11 GeV/c and Cherenkov Ring Imaging at the SLD

    SciTech Connect

    Bienz, T.L.

    1990-07-01

    This thesis is divided into two sections, which describe portions of the data acquisition system and online software for the Cherenkov Ring Imaging Detector (CRID) for the SLD, and analyses of several low cross section strangeonium channels in data from the LASS spectrometer. The CRID section includes a description of the data acquisition system, determination of the preamplifier gain, and development of an online pulse finding algorithm based on deconvolution. Deconvolution uses knowledge of the preamplifier impulse response to aid in pulse finding. The algorithm is fast and shows good single pulse resolution and excellent double pulse resolution in preliminary tests. The strangeonium analyses are based on data from a 4.1 event/nanobarn exposure of the LASS spectrometer in K{sup {minus}}p interactions at 11 GeV/c, and include studies of {Lambda}{eta}{pi}{sup {plus}}{pi}{sup {minus}}, {Lambda}{Kappa}*{Kappa}*, and {Lambda}{phi}{phi}.

  8. A proposed measurement of the reverse Cherenkov radiation effect in a metamaterial-loaded circular waveguide

    SciTech Connect

    Shchegolkov, Dmitry; Azad, Abul K; O' Hara, John F; Smirnova, Evgenya I

    2009-01-01

    The authors have recently proposed an experiment on verification of the Reverse Cherenkov Radiation (RCR) effect in a Left-Handed-Material-loaded waveguide. Applications of the RCR effect may range from novel higher-order-mode suppressors in microwave and millimeter-wave sources to improved particle detectors for satellite non-proliferation missions. The experimental configuration includes a circular waveguide filled with an artificial metamaterial with simultaneously negative permittivity and permeability, in which the electromagnetic wave with a frequency of 95 GHz will interact with an electron beam. They have demonstrated that for certain values of effective permittivity and permeability only the backward-propagating mode can be exited by the electron beam. At the conference they will present some newly developed metamaterial designs, which they plan to employ for producing the proper effective medium parameters for this experiment.

  9. Diagnostics of Fast Electrons within Castor Tokamak by Means of a Modified Cherenkov-Type Probe

    SciTech Connect

    Zebrowski, J.; Jakubowski, L.; Sadowski, M. J.; Malinowski, K.; Jakubowski, M.; Weinzettl, V.; Stockel, J.; Peterka, M.

    2008-03-19

    The paper reports on experimental studies performed within the CASTOR tokamak, which was operated at IPP in Prague, Czech Republic, during the last experimental campaign carried out in autumn 2006. The main aim was to implement a new diagnostic technique for measurements of energetic (>80 keV) electrons within the tokamak edge plasma region. The technique was based on the use of a Cherenkov-type probe similar to the first prototype detector, which was tested during the previous experiments with the CASTOR device. In particular, the distributions of fast electrons in a standard scenario at different values of plasma current I{sub p}, and toroidal magnetic field B{sub T} are determined.

  10. Evaluation of Photo Multiplier Tube candidates for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Mirzoyan, R.; Müller, D.; Hanabata, Y.; Hose, J.; Menzel, U.; Nakajima, D.; Takahashi, M.; Teshima, M.; Toyama, T.; Yamamoto, T.

    2016-07-01

    Photo Multiplier Tubes (PMTs) are the most wide spread detectors for fast, faint light signals. Six years ago, an improvement program for the PMT candidates for the Cherenkov Telescope Array (CTA) project was started with the companies Hamamatsu Photonics K.K. and Electron Tubes Enterprises Ltd. (ETE). For maximizing the performance of the CTA imaging cameras we need PMTs with outstanding good quantum efficiency, high photoelectron collection efficiency, short pulse width, very low afterpulse probability and transit time spread. We will report on the measurements of PMT R-12992-100 from Hamamatsu as their final product and the PMT D573KFLSA as one of the latest test versions from ETE as candidate PMTs for the CTA project.

  11. Readout electronics for the Wide Field of view Cherenkov/Fluorescence Telescope Array

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Zhang, S.; Zhang, Y.; Zhou, R.; Bai, L.; Zhang, J.; Huang, J.; Yang, C.; Cao, Z.

    2015-08-01

    The aim of the Large High Altitude Air Shower Observatory (LHAASO), supported by IHEP of the Chinese Academy of Sciences, is a multipurpose project with a complex detectors array for high energy gamma ray and cosmic ray detection. The Wide Field of view Cherenkov Telescope Array (WFCTA), as one of the components of the LHAASO project, aim to tag each primary particle that causes an air shower. The WFCTA is a portable telescope array used to detect cosmic ray spectra. The design of the readout electronics of the WFCTA is described in this paper Sixteen photomultiplier tubes (PMTs), together with their readout electronics are integrated into a single sub-cluster. To maintain good resolution and linearity over a wide dynamic range, a dual-gain amplification configuration on an analog board is used The digital board contains two 16channel 14-bit, 50 Msps analog-to-digital converters (ADC) and its power consumption, noise level, and relative deviation are all tested.

  12. Dimensionless parameterization of lidar for laser remote sensing of the atmosphere and its application to systems with SiPM and PMT detectors.

    PubMed

    Agishev, Ravil; Comerón, Adolfo; Rodriguez, Alejandro; Sicard, Michaël

    2014-05-20

    In this paper, we show a renewed approach to the generalized methodology for atmospheric lidar assessment, which uses the dimensionless parameterization as a core component. It is based on a series of our previous works where the problem of universal parameterization over many lidar technologies were described and analyzed from different points of view. The modernized dimensionless parameterization concept applied to relatively new silicon photomultiplier detectors (SiPMs) and traditional photomultiplier (PMT) detectors for remote-sensing instruments allowed predicting the lidar receiver performance with sky background available. The renewed approach can be widely used to evaluate a broad range of lidar system capabilities for a variety of lidar remote-sensing applications as well as to serve as a basis for selection of appropriate lidar system parameters for a specific application. Such a modernized methodology provides a generalized, uniform, and objective approach for evaluation of a broad range of lidar types and systems (aerosol, Raman, DIAL) operating on different targets (backscatter or topographic) and under intense sky background conditions. It can be used within the lidar community to compare different lidar instruments. PMID:24922200

  13. A sensitive and versatile detector for atmospheric NO2 and NOx based on blue diode laser cavity ring-down spectroscopy.

    PubMed

    Fuchs, Hendrik; Dubé, William P; Lerner, Brian M; Wagner, Nicholas L; Williams, Eric J; Brown, Steven S

    2009-10-15

    A sensitive, small detector was developed for atmospheric NO2 and NOx concentration measurements. NO2 is directly detected by laser diode based cavity ring-down spectroscopy (CRDS) at 404 nm. The sum of NO and NO2 (=NOx) is simultaneously measured in a second cavity by quantitative conversion of ambient NO to NO2 in excess ozone. Interferences due to absorption by other trace gases at 404 nm, such as ozone and water vapor, are either negligible or small and are easily quantified. The limit of detection is 22 pptv (2sigma precision) for NO2 at 1 s time resolution. The conversion efficiency of NO to NO2 is 99% in excess O3. The accuracy of the NO2 measurement is mainly limited by the NO2 absorption cross section to +/-3%. Because of the formation of undetectable higher nitrogen oxides in subsequent reactions of NO2 with ozone in the NOx channel, the (1sigma) accuracy of the NOx measurement is increased to approximately +/-5% depending on the level of NOx. The new instrument was designed to be easily deployed in the field with respect to size, weight and consumables. Measurements were validated against a photolysis/chemiluminescence detector during six days of sampling ambient air with colocated inlets. The data sets for NO2, NO and NOx exhibit high correlation and good agreement within the combined accuracies of both methods. Linear fits for all three species give similar slopes of 0.99 in ambient air. PMID:19921901

  14. Cosmic-ray Electrons and Atmospheric Gamma-rays in 1-30 GeV observed with Balloon-borne CALET prototype detector

    NASA Astrophysics Data System (ADS)

    Niita, Tae; Fuke, Hideyuki; Yoshida, Kenji; Katayose, Yusaku; Torii, Shoji; Akaike, Yosui; Katsuaki Kasahara, ., , prof.; Tamura, Tadahisa; Ueyama, Yoshitaka; Ozawa, Shunsuke; Shimizu, Yuki; Kyutan, Marie; Murakami, Hiroyuki; Ito, Daijiro; Karube, Mikihiko; Kondo, Keinosuke

    2012-07-01

    We carried out the balloon experiments using CALET (CALorimetric Electron Telescope) proto-type detectors in May 2006 (bCALET-1) and in August 2009 (bCALET-2) for verification of the detector performance and of the capability of measuring cosmic rays at high altitude. The bCALET-2 instrument for observing electrons and gamma-rays is composed of an imaging calorimeter, consisting of 4096 scintillating fibers and 7 tungsten plates of 3.6 radiation lengths depth in total, and a total absorption calorimeter, consisting of 60 BGO logs of 13.4 radiation lengths depth. The bCALET-2 was launched at the Taiki Aerospace Research Field, Japan Aerospace Exploration Agency, in Hokkaido, and flew successfully for 2.5 hours at a level altitude of 35 km. We will present energy spectra of the 1ry and 2ry electrons and the atmospheric gamma-rays in the energy range of 1-30 GeV observed by bCALET-2. The results will be compared with our previous observations, bCALET-1 and BETS.

  15. Dimensionless parameterization of lidar for laser remote sensing of the atmosphere and its application to systems with SiPM and PMT detectors.

    PubMed

    Agishev, Ravil; Comerón, Adolfo; Rodriguez, Alejandro; Sicard, Michaël

    2014-05-20

    In this paper, we show a renewed approach to the generalized methodology for atmospheric lidar assessment, which uses the dimensionless parameterization as a core component. It is based on a series of our previous works where the problem of universal parameterization over many lidar technologies were described and analyzed from different points of view. The modernized dimensionless parameterization concept applied to relatively new silicon photomultiplier detectors (SiPMs) and traditional photomultiplier (PMT) detectors for remote-sensing instruments allowed predicting the lidar receiver performance with sky background available. The renewed approach can be widely used to evaluate a broad range of lidar system capabilities for a variety of lidar remote-sensing applications as well as to serve as a basis for selection of appropriate lidar system parameters for a specific application. Such a modernized methodology provides a generalized, uniform, and objective approach for evaluation of a broad range of lidar types and systems (aerosol, Raman, DIAL) operating on different targets (backscatter or topographic) and under intense sky background conditions. It can be used within the lidar community to compare different lidar instruments.

  16. Spin-Cherenkov effect and magnonic Mach cones

    NASA Astrophysics Data System (ADS)

    Yan, Ming; Kákay, Attila; Andreas, Christian; Hertel, Riccardo

    2013-12-01

    We report on the Cherenkov-type excitation of spin waves (SWs) in ferromagnets. Our micromagnetic simulations show that a localized magnetic field pulse moving sufficiently fast along the surface of a ferromagnet generates a SW boom, with a Mach-type cone of propagating wave fronts. The SWs are formed when the velocity of the source exceeds the propagation speed of SWs. Unlike the single cone of the usual Cherenkov effect, we find that the magnetic Mach cone consists of two wave fronts with different wave numbers. In patterned thin strips, this magnetic analog of the Cherenkov effect should enable the excitation of SWs with well-defined and velocity-dependent frequency. It thereby provides a promising route towards tunable SW generation, with important potential for applications in magnonic devices.

  17. Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams

    DOE PAGESBeta

    Adli, E.; Gessner, S. J.; Corde, S.; Hogan, M. J.; Bjerke, H. H.

    2015-02-09

    We describe a beam profile monitor design based on Cherenkov light emitted from a charged particle beam in an air gap. The main components of the profile monitor are silicon wafers used to reflect Cherenkov light onto a camera lens system. The design allows for measuring large beam sizes, with large photon yield per beam charge and excellent signal linearity with beam charge. Furthermore, the profile monitor signal is independent of the particle energy for ultrarelativistic particles. Different design and parameter considerations are discussed. A Cherenkov light-based profile monitor has been installed at the FACET User Facility at SLAC. Finally,more » we report on the measured performance of this profile monitor.« less

  18. MARS - CheObs ed. -- A flexible Software Framework for future Cherenkov Telescopes

    NASA Astrophysics Data System (ADS)

    Bretz, T.; Dorner, D.

    2010-04-01

    In gamma-ray astronomy, a new ground-based project named DWARF (Dedicated multiWavelength Agn Research Facility) is entering the field. It is a Cherenkov telescope project aimed at long-term monitoring of the brightest AGNs in the TeV energy range. One of the former HEGRA telescopes is being refurbished and upgraded with a Geigermode-APD camera. It is planned to be operated as a robotic telescope on the Canary Island of La Palma. Using new technologies, an improvement in sensitivity and an energy threshold of 400GeV are expected. Future plans foresee more small Cherenkov telescopes around the globe enabling for the first time 24 h monitoring in the VHE range. Long-term observations of the brightest AGNs provide the possibility to search for orbital modulation of blazar emission due to super-massive black hole binaries, to study the statistics of flares and their physical origin, and to correlate the data with corresponding data from the neutrino observatory IceCube to search for evidence of hadronic emission processes. For this project, a flexible and user friendly software package is available: Modular Analysis and Reconstruction Software - Cherenkov Observatory edition (MARS - CheObs ed.). The package provides a framework for any event-based analysis. For the application in the Imaging Air Cherenkov Technique, various methods and algorithms are available. Currently, it is being used for the MAGIC telescope. To allow for automatic analysis, MARS - CheObs ed. includes an automation concept which allows not only for automatic processing of the data, but also for automatic production of simulated data. For the DWARF project, a simulation program (ceres) has been developed and included in the software package. Using this, a design study for the technical upgrades of the telescope was performed. The simulation of the showers in the atmosphere is performed using the CORSIKA package. The output of this is fed into the telescope simulation ceres. Proper simulations are

  19. CHIPS Neutrino Detector Research and Development

    NASA Astrophysics Data System (ADS)

    Salazar, Ramon; Vahle, Patricia; Chips Collaboration

    2015-04-01

    The CHIPS R&D project is an effort to develop affordable megaton-scale neutrino detectors. The CHIPS strategy calls for submerging water Cherenkov detectors deep under water. The surrounding water acts as structural support, minimizing large initial investments in costly infrastructure, and serves as an overburden, shielding the detector from cosmic rays and eliminating the need for expensive underground construction. Additional cost savings will be achieved through photodetector development and optimization of readout geometry. In summer 2014 a small prototype of the CHIPS detector was deployed in the flooded Wentworth Mine Pit in Northern Minnesota. The detector has been recording data underwater throughout the fall and winter. In this talk, we will discuss lessons learned from the prototyping experience and the plans for submerging much larger detectors in future years.

  20. Lorentz-invariant formulation of Cherenkov radiation by tachyons

    NASA Technical Reports Server (NTRS)

    Jones, F. C.

    1972-01-01

    Previous treatments of Cherenkov radiation, electromagnetic and gravitational, by tachyons were in error because the prescription employed to cut off the divergent integral over frequency is not a Lorentz invariant procedure. The resulting equation of motion for the tachyon is therefore not covariant. The proper procedure requires an extended, deformable distribution of charge or mass and yields a particularly simple form for the tachyon's world line, one that could be deduced from simple invariance considerations. It is shown that Cherenkov radiation by tachyons implys their ultimate annihilation with an antitachyon and demonstrates a disturbing property of tachyons, namely the impossibility of specifying arbitrary Cauchy data even in a purely classical theory.

  1. Cherenkov Radiation from Jets in Heavy-ion Collisions

    SciTech Connect

    Koch, Volker; Majumder, Abhijit; Wang, Xin-Nian

    2005-07-26

    The possibility of Cherenkov-like gluon bremsstrahlung in dense matter is studied. We point out that the occurrence of Cherenkov radiation in dense matter is sensitive to the presence of partonic bound states. This is illustrated by a calculation of the dispersion relation of a massless particle in a simple model in which it couples to two different massive resonance states. We further argue that detailed spectroscopy of jet correlations can directly probe the index of refraction of this matter, which in turn will provide information about the mass scale of these partonic bound states.

  2. The glass cold-shaping technology for the mirrors of the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Canestrari, Rodolfo; Bonnoli, Giacomo; Crimi, Giuseppe; Fiorini, Mauro; Giro, Enrico; La Palombara, Nicola; Pareschi, Giovanni; Perri, Luca; Rodeghiero, Gabriele; Sironi, Giorgia; Stringhetti, Luca; Toso, Giorgio; Pelliciari, Carlo

    2014-07-01

    The next generation of imaging atmospheric Cherenkov telescopes will require the production of thousands of mirror segments; an unprecedented amount of optical surface. To accomplish this, the Italian Istituto Nazionale di AstroFisica (INAF) has recently developed a successful technique. This method, called glass cold-shaping, is mainly intended for the manufacturing of mirrors for optical systems with an angular resolution of a few arcminutes, intended to operate in extreme environments. Its principal mechanical features are very low weight and high rigidity of the resulting segments, and its cost and production time turn out to be very competitive as well. The process is based on the shaping of thin glass foils by means of forced bending at room temperature; a sandwich structure is then assembled for retaining the imposed shape. These mirrors are composted of commercial, off-the-shelf materials. In this contribution we give an overview of the latest results achieved in the manufacturing of the pre-production series of mirrors for the Medium Size and Small Size Telescopes of the Cherenkov Telescope Array observatory.

  3. Simulated gamma-ray pulse profile of the Crab pulsar with the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Burtovoi, A.; Zampieri, L.

    2016-07-01

    We present simulations of the very high energy (VHE) gamma-ray light curve of the Crab pulsar as observed by the Cherenkov Telescope Array (CTA). The CTA pulse profile of the Crab pulsar is simulated with the specific goal of determining the accuracy of the position of the interpulse. We fit the pulse shape obtained by the Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) telescope with a three-Gaussian template and rescale it to account for the different CTA instrumental and observational configurations. Simulations are performed for different configurations of CTA and for the ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) mini-array. The northern CTA configuration will provide an improvement of a factor of ˜3 in accuracy with an observing time comparable to that of MAGIC (73 h). Unless the VHE spectrum above 1 TeV behaves differently from what we presently know, unreasonably long observing times are required for a significant detection of the pulsations of the Crab pulsar with the high-energy-range sub-arrays. We also found that an independent VHE timing analysis is feasible with Large Size Telescopes. CTA will provide a significant improvement in determining the VHE pulse shape parameters necessary to constrain theoretical models of the gamma-ray emission of the Crab pulsar. One of such parameters is the shift in phase between peaks in the pulse profile at VHE and in other energy bands that, if detected, may point to different locations of the emission regions.

  4. The ASTRI SST-2M prototype for the Cherenkov Telescope Array: prototype technologies goals and strategies for the future SST

    NASA Astrophysics Data System (ADS)

    Marchiori, Gianpietro; Busatta, Andrea; Giacomel, Stefano; Folla, Ivan; Valsecchi, Marco; Canestrari, Rodolfo; Bonnoli, Giacomo; Cascone, Enrico; Conconi, Paolo; Fiorini, Mauro; Giro, Enrico; La Palombara, Nicola; Pareschi, Giovanni; Perri, Luca; Rodeghiero, Gabriele; Sironi, Giorgia; Stringhetti, Luca; Toso, Giorgio; Tosti, Gino; Pellicciari, Carlo

    2014-07-01

    The Cherenkov Telescope Array (CTA) observatory will represent the next generation of Imaging Atmospheric Cherenkov Telescope. Using a combination of large-, medium-, and small-scale telescopes (LST, MST, SST, respectively), it will explore the Very High Energy domain from a few tens of GeVup to about few hundreds of TeV with unprecedented sensitivity, angular resolution and imaging quality. In this framework, the Italian ASTRI program, led by the Italian National Institute of Astrophysics (INAF) developed a 4-meter class telescope, which will adopt an aplanatic, wide-field, double-reflection optical layout in a Schwarzschild- Couder configuration. Within this program INAF assigned to the consortium between Galbiati Group and EIE Group the construction, assembly and tests activities of the prototype named ASTRI SST-2M. On the basis of the lesson learnt from the prototype, other telescopes will be produced, starting from a re-design phase, in order to optimize performances and the overall costs and production schedule for the CTA-SST telescope. This paper will firstly give an overview of the concept for the SST prototype mount structure. In this contest, the technologies adopted for the design, manufacturing and tests of the entire system will be presented. Moreover, a specific focus on the challenges of the prototype and the strategies associated with it will be provided, in order to outline the near future performance goals for this type of Cherenkov telescopes employed for Gamma ray science.

  5. Investigation of Hamamatsu H8500 phototubes as single photon detectors

    NASA Astrophysics Data System (ADS)

    Montgomery, R. A.; Hoek, M.; Lucherini, V.; Mirazita, M.; Orlandi, A.; Anefalos Pereira, S.; Pisano, S.; Rossi, P.; Viticchiè, A.; Witchger, A.

    2015-08-01

    We have investigated the response of a significant sample of Hamamatsu H8500 MultiAnode PhotoMultiplier Tubes (MAPMTs) as single photon detectors, in view of their use in a ring imaging Cherenkov counter for the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility. For this, a laser working at 407.2 nm wavelength was employed. The sample is divided equally into standard window type, with a spectral response in the visible light region, and UV-enhanced window type MAPMTs. The studies confirm the suitability of these MAPMTs for single photon detection in such a Cherenkov imaging application.

  6. VERITAS Distant Laser Calibration and Atmospheric Monitoring

    SciTech Connect

    Hui, C. M.

    2008-12-24

    As a calibrated laser pulse propagates through the atmosphere, the intensity of the Rayleigh scattered light arriving at the VERITAS telescopes can be calculated precisely. This allows for absolute calibration of imaging atmospheric Cherenkov telescopes (IACT) to be simple and straightforward. In these proceedings, we present the comparison between laser data and simulation to estimate the light collection efficiencies of the VERITAS telescopes, and the analysis of multiple laser data sets taken in different months for atmospheric monitoring purpose.

  7. [Measurement of chlorodifluoromethane(HCFC-22) in the atmosphere by using an O2-induced electron capture detector (ECD)].

    PubMed

    Sun, H; Chen, L; Yue, Z; Sun, G; Ma, W

    2001-07-01

    Chlorodifluoromethane (CHClF2, HCFC-22), a typical substitute of dichlorodifluoromethane(CF2Cl2, CFC-12), which atmospheric concentration was only at 10(-12) V/V level. After preconcentrated air sample, O2-Induced method was used to enhance sensitivity of ECD response to HCFC-22. When O2 concentration in carrier gas was 0.54%, there was the greatest value of S/N(signal to noise) and ECD response increased by about 500 times. With the study of other conditions, such as selection of the ECD temperature, programing of the column oven temperature and carrier gas flow, a practicable analysis method with high sensitivity of ECD was established.

  8. [Measurement of chlorodifluoromethane(HCFC-22) in the atmosphere by using an O2-induced electron capture detector (ECD)].

    PubMed

    Sun, H; Chen, L; Yue, Z; Sun, G; Ma, W

    2001-07-01

    Chlorodifluoromethane (CHClF2, HCFC-22), a typical substitute of dichlorodifluoromethane(CF2Cl2, CFC-12), which atmospheric concentration was only at 10(-12) V/V level. After preconcentrated air sample, O2-Induced method was used to enhance sensitivity of ECD response to HCFC-22. When O2 concentration in carrier gas was 0.54%, there was the greatest value of S/N(signal to noise) and ECD response increased by about 500 times. With the study of other conditions, such as selection of the ECD temperature, programing of the column oven temperature and carrier gas flow, a practicable analysis method with high sensitivity of ECD was established. PMID:11569107

  9. A hybrid version of the Whipple observatory's air Cherenkov imaging camera for use in moonlight

    NASA Astrophysics Data System (ADS)

    Chantell, M. C.; Akerlof, C. W.; Badran, H. M.; Buckley, J.; Carter-Lewis, D. A.; Cawley, M. F.; Connaughton, V.; Fegan, D. J.; Fleury, P.; Gaidos, J.; Hillas, A. M.; Lamb, R. C.; Pare, E.; Rose, H. J.; Rovero, A. C.; Sarazin, X.; Sembroski, G.; Schubnell, M. S.; Urban, M.; Weekes, T. C.; Wilson, C.

    1997-02-01

    A hybrid version of the Whipple Observatory's atmospheric Cherenkov imaging camera that permits observation during periods of bright moonlight is described. The hybrid camera combines a blue-light blocking filter with the standard Whipple imaging camera to reduce sensitivity to wavelengths greater than 360 nm. Data taken with this camera are found to be free from the effects of the moonlit night-sky after the application of simple off-line noise filtering. This camera has been used to successfully detect TeV gamma rays, in bright moon light, from both the Crab Nebula and the active galactic nucleus Markarian 421 at the 4.9σ and 3.9σ levels of statistical significance, respectively. The energy threshold of the camera is estimated to be 1.1 ( +0.6/-0.3) TeV from Monte Carlo simulations.

  10. Characterization of flash γ-ray detectors that operate in the Trad/s range

    NASA Astrophysics Data System (ADS)

    Sanford, T. W. L.; Halbleib, J. A.; Mock, R. C.; Beutler, D. E.; Carlson, G. A.; Poukey, J. W.

    1990-09-01

    Compton-diode detectors, scintillator-photodiode detectors, and Cherenkov-photodiode detectors, designed to measure the intense pulsed bremsstrahlung field of HERMES III, are described and characterized in the field of HERMES III. Measurements and modeling show that (1) the Compton-diode detector measures dose rate and is capable of linear operation up to 2.5×10 12 rad/s, (2) the scintillator-photodiode detector measures dose rate only when the rate is less then 2×10 11 rad/s, and (3) the Cherenkov photodiode detector can be used o place limits on the radiation pulse over the range ˜ 2.5×10 10 to ˜ 2.5×10 12 rad/s. A by-product of the measurements and modeling is the determination of the temporal behavior of the forward field of HERMES III near the beam axis.

  11. Particle identification with the TOP and ARICH detectors at Belle II

    NASA Astrophysics Data System (ADS)

    Torassa, E.

    2016-07-01

    The SuperKEKB e+e- collider will provide 40 times higher instantaneous luminosity than the KEKB collider. The Belle II detector, located at the collision point, is the upgrade of the Belle detector. The particle identification will be improved by replacing the aerogel threshold counter with two new high performance Cherenkov detectors: the time-of-propagation (TOP) in the barrel region and the focusing aerogel (ARICH) in the forward region. The time-of-propagation sub-detector consists of quartz radiator bars and micro-channel plate photomultiplier tubes. The Cherenkov photons are produced and propagated through the quartz radiator, and after multiple internal reflections they are detected by the photomultiplier tubes. Photons with different Cherenkov angles reach different photomultiplier channels and arrive at different times. The time and the position convolution is used for the reconstruction of the Cherenkov angle. The focusing aerogel consists of a double layer aerogel radiator, an expansion volume and a photon detector. The aerogel thickness and the refractive indices of the two layers are optimized to focus the two light cones at the detection surface. The key features of these two detectors, the performance studies, and the construction progress are presented.

  12. Evaluation of the optical cross talk level in the SiPMs adopted in ASTRI SST-2M Cherenkov Camera using EASIROC front-end electronics

    NASA Astrophysics Data System (ADS)

    Impiombato, D.; Giarrusso, S.; Mineo, T.; Agnetta, G.; Biondo, B.; Catalano, O.; Gargano, C.; La Rosa, G.; Russo, F.; Sottile, G.; Belluso, M.; Billotta, S.; Bonanno, G.; Garozzo, S.; Marano, D.; Romeo, G.

    2014-02-01

    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana), is a flagship project of the Italian Ministry of Education, University and Research whose main goal is the design and construction of an end-to-end prototype of the Small Size of Telescopes of the Cherenkov Telescope Array. The prototype, named ASTRI SST-2M, will adopt a wide field dual mirror optical system in a Schwarzschild-Couder configuration to explore the VHE range of the electromagnetic spectrum. The camera at the focal plane is based on Silicon Photo-Multipliers detectors which is an innovative solution for the detection astronomical Cherenkov light. This contribution reports some preliminary results on the evaluation of the optical cross talk level among the SiPM pixels foreseen for the ASTRI SST-2M camera.

  13. Possible usage of Cherenkov photons to reduce the background in a 136Xe neutrino-less double-beta decay experiment

    NASA Astrophysics Data System (ADS)

    Signorelli, G.; Dussoni, S.

    2016-07-01

    One of the main backgrounds in the search for 136Xe nutrino-less double-beta decay (0 νββ) is the signal from Compton scattering of photons with energy around the decay endpoint at 2.458 MeV. Electrons in liquid xenon emit scintillation light at 178 nm. Liquid xenon being extremely transparent to ultra violet light it is in principle possible to discriminate one particle events (such as the Compton background) from two particle events (double-beta decay signals) by the amount of Cherenkov radiation emitted. The identification of the Cherenkov photons may be performed by looking at the different time structure of the signal with respect to the scintillation, by selecting photons with wavelengths larger than the typical Xenon scintillation light, and by the different emission topology. A proof-of-principle study of this approach is presented here together with preliminary studies on possible detectors for the two light components at different wavelengths.

  14. Status and Aims of the DUMAND Neutrino Project: the Ocean as a Neutrino Detector

    DOE R&D Accomplishments Database

    Roberts, A.; Blood, H.; Learned, J.; Reines, F.

    1976-07-01

    The possibility of using the ocean as a neutrino detector is considered. Neutrino-produced interactions result in charged particles that generate Cherenkov radiation in the water, which can be detected by light-gathering equipment and photomultipliers. The properties of the ocean as seen from this standpoint are critically examined, and the advantages and disadvantages pointed out. Possible uses for such a neutrino detector include (1) the detection of neutrinos emitted in gravitational collapse of stars (supernova production), not only in our own galaxy, but in other galaxies up to perhaps twenty-million light-years away, (2) the extension of high-energy neutrino physics, as currently practiced up to 200 GeV at high-energy accelerators, to energies up to 50 times higher, using neutrinos generated in the atmosphere by cosmic rays, and (3) the possible detection of neutrinos produced by cosmic-ray interactions outside the earth`s atmosphere. The technology for such an undertaking seems to be within reach.

  15. Radium-228 analysis of natural waters by Cherenkov counting of Actinium-228.

    PubMed

    Aleissa, Khalid A; Almasoud, Fahad I; Islam, Mohammed S; L'Annunziata, Michael F

    2008-12-01

    The activities of (228)Ra in natural waters were determined by the Cherenkov counting of the daughter nuclide (228)Ac. The radium was pre-concentrated on MnO(2) and the radium purified via ion exchange and, after a 2-day period of incubation to allow for secular equilibrium between the parent-daughter (228)Ra((228)Ac), the daughter nuclide (228)Ac was isolated by ion exchange according to the method of Nour et al. [2004. Radium-228 determination of natural waters via concentration on manganese dioxide and separation using Diphonix ion exchange resin. Appl. Radiat. Isot. 61, 1173-1178]. The Cherenkov photons produced by (228)Ac were counted directly without the addition of any scintillation reagents. The optimum Cherenkov counting window, sample volume, and vial type were determined experimentally to achieve optimum Cherenkov photon detection efficiency and lowest background count rates. An optimum detection efficiency of 10.9+/-0.1% was measured for (228)Ac by Cherenkov counting with a very low Cherenkov photon background of 0.317+/-0.013cpm. The addition of sodium salicylate into the sample counting vial at a concentration of 0.1g/mL yielded a more than 3-fold increase in the Cherenkov detection efficiency of (228)Ac to 38%. Tests of the Cherenkov counting technique were conducted with several water standards of known activity and the results obtained compared closely with a conventional liquid scintillation counting technique. The advantages and disadvantages of Cherenkov counting compared to liquid scintillation counting methods are discussed. Advantages include much lower Cherenkov background count rates and consequently lower minimal detectable activities for (228)Ra and no need for expensive environmentally unfriendly liquid scintillation cocktails. The disadvantages of the Cherenkov counting method include the need to measure (228)Ac Cherenkov photon detection efficiency and optimum Cherenkov counting volume, which are not at all required when liquid

  16. Radium-228 analysis of natural waters by Cherenkov counting of Actinium-228.

    PubMed

    Aleissa, Khalid A; Almasoud, Fahad I; Islam, Mohammed S; L'Annunziata, Michael F

    2008-12-01

    The activities of (228)Ra in natural waters were determined by the Cherenkov counting of the daughter nuclide (228)Ac. The radium was pre-concentrated on MnO(2) and the radium purified via ion exchange and, after a 2-day period of incubation to allow for secular equilibrium between the parent-daughter (228)Ra((228)Ac), the daughter nuclide (228)Ac was isolated by ion exchange according to the method of Nour et al. [2004. Radium-228 determination of natural waters via concentration on manganese dioxide and separation using Diphonix ion exchange resin. Appl. Radiat. Isot. 61, 1173-1178]. The Cherenkov photons produced by (228)Ac were counted directly without the addition of any scintillation reagents. The optimum Cherenkov counting window, sample volume, and vial type were determined experimentally to achieve optimum Cherenkov photon detection efficiency and lowest background count rates. An optimum detection efficiency of 10.9+/-0.1% was measured for (228)Ac by Cherenkov counting with a very low Cherenkov photon background of 0.317+/-0.013cpm. The addition of sodium salicylate into the sample counting vial at a concentration of 0.1g/mL yielded a more than 3-fold increase in the Cherenkov detection efficiency of (228)Ac to 38%. Tests of the Cherenkov counting technique were conducted with several water standards of known activity and the results obtained compared closely with a conventional liquid scintillation counting technique. The advantages and disadvantages of Cherenkov counting compared to liquid scintillation counting methods are discussed. Advantages include much lower Cherenkov background count rates and consequently lower minimal detectable activities for (228)Ra and no need for expensive environmentally unfriendly liquid scintillation cocktails. The disadvantages of the Cherenkov counting method include the need to measure (228)Ac Cherenkov photon detection efficiency and optimum Cherenkov counting volume, which are not at all required when liquid

  17. The photon detector of the HERMES dual-radiator RICH

    NASA Astrophysics Data System (ADS)

    Aschenauer, E. C.; Van der Kerckhove, K.

    1999-08-01

    To provide hadron identification over the full kinematic range (2-20GeV) of the HERMES experiment, the gas threshold Cherenkov counters were replaced by a dual-radiator ring-imaging Cherenkov detectors incorporating for the first time aerogel (SiO2) and C4F10 gas as radiator materials. This combination of radiators requires a photon detector that is sensitive over wavelengths from ultraviolet to 700nm. Commercially available `3/4 in.' photo-multipliers were chosen to form an array of 2000 for each of two photon-detectors. Exhaustive calibration and sorting of the phototubes prior to installation resulted in very low noise hit rates in the LeCroy PCOS4 readout system, with a uniform effective threshold of 0.1 photo-electrons.

  18. In situ, high sensitivity, measurement of 90strontium in ground water using Cherenkov light

    NASA Astrophysics Data System (ADS)

    Bowyer, T. W.; Geelhood, B. D.; Hossbach, T. W.; Hansen, R.; Wilcox, W. A.

    2000-03-01

    The measurement of 90Sr in soils and ground water is important for characterization and remediation of radioactively contaminated sites. Measuring the 90Sr content to a few pCi/g of soil has been accomplished based on a design of scintillating fibers in a multilayered configuration measuring the high-energy beta emitted from 90Y decay (when in secular equilibrium with 90Sr), but has not been applied to water because the technique is sensitive to only the first few mm of soil. The volume of the source to which the detector is sensitive limits the theoretical sensitivity of such a detector, unless chemical preprocessing to strip the 90Sr from the water is performed. 90Sr activity in water can be quantified by detecting the high-energy beta particle by the Cherenkov light it produces when the high-energy beta from 90Y passes through the medium. We have used this phenomenon to sensitively measure 90Sr ( 90Y) from a volume of water large enough (765 cm 3) to make very sensitive measurements with short count times. For counting intervals of about 1000 s, we were able to achieve a minimum detectable concentration (MDC) (at 4.65 σ above background) of 14 pCi/L, and for 3000 s counts the MDC dropped to the drinking water limit of 8 pCi/L.

  19. Noise and spurious pulses for Cherenkov light detection with 10-inch and 3-inch photomultipliers

    SciTech Connect

    Giordano, V.; Aiello, S.; Leonora, E. E-mail: Valentina.Giordano@ct.infn.it; Collaboration: KM3NeT Collaboration

    2014-11-18

    A large number of large photocathode area photomultipliers are widely used in astroparticle physics detectors to measure Cherenkov light in media like water or ice. In neutrino telescopes the key element of the detector is the optical module, which consists of one or more photodetectors inside a transparent pressure-resistant glass sphere. The glass sphere serves as mechanical protection while ensuring good light transmission. The performance of the telescope is largely dependent on the presence of noise pulses present on the anode of the photomultipliers. A study was conducted of noise pulses of Hamamatsu 10-inch and 3-inch diameter photomultipliers measuring time and charge distributions of dark pulses, pre-pulses, delayed pulses, and after-pulses. In particular, an analysis on multiple after-pulses was performed on both photomultiplier models. A digital oscilloscope was used to acquire all the pulses after the main pulse during a time window of 16μs for an off-line analysis to determine the charge and time spectra and a correlation between the arrival times and the charge of each after-pulse.

  20. The TORCH PMT: a close packing, multi-anode, long life MCP-PMT for Cherenkov applications

    NASA Astrophysics Data System (ADS)

    Conneely, T. M.; van Dijk, M. W. U.; D'Ambrosio, C.; Brook, N.; Castillo García, L.; Cowie, E. N.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Howorth, J.; Lapington, J.; Milnes, J.; Piedigrossi, D.; Slatter, C.

    2015-05-01

    Photek (U.K.) and the TORCH collaboration are undertaking a three year development program to produce a novel square MCP-PMT for single photon detection. The TORCH detector aims to provide particle identification in the 2-10 GeV/c momentum range, using a Time-of-Flight method based on Cherenkov light. It is a stand-alone R&D project with possible application in LHCb, and has been proposed for the LHCb Upgrade. The Microchannel Plate (MCP) detector will provide a single photon timing accuracy of 40 ps, and its development will include the following properties: (i) Long lifetime up to at least 5 C/cm2; (ii) Multi-anode output with a spatial resolution of 6 mm and 0.4 mm respectively in the horizontal and vertical directions, incorporating a novel charge-sharing technique; (iii) Close packing on two opposing sides with an active area fill factor of 88% in the horizontal direction. Results from simulations modelling the MCP detector performance factoring in the pulse height variation from the detector, NINO threshold levels and potential charge sharing techniques that enhance the position resolution beyond the physical pitch of the pixel layout will be discussed. Also, a novel method of coupling the MCP-PMT output pads using Anisotropic Conductive Film (ACF) will be described. This minimises parasitic input capacitance by allowing very close proximity between the frontend electronics and the MCP detector.

  1. Software Development for Ring Imaging Detector

    NASA Astrophysics Data System (ADS)

    Torisky, Benjamin

    2016-03-01

    Jefferson Lab (Jlab) is performing a large-scale upgrade to their Continuous Electron Beam Accelerator Facility (CEBAF) up to 12GeV beam. The Large Acceptance Spectrometer (CLAS12) in Hall B is being upgraded and a new Ring Imaging Cherenkov (RICH) detector is being developed to provide better kaon - pion separation throughout the 3 to 12 GeV range. With this addition, when the electron beam hits the target, the resulting pions, kaons, and other particles will pass through a wall of translucent aerogel tiles and create Cherenkov radiation. This light can then be accurately detected by a large array of Multi-Anode PhotoMultiplier Tubes (MA-PMT). I am presenting an update on my work on the implementation of Java based reconstruction programs for the RICH in the CLAS12 main analysis package.

  2. Software development for a Ring Imaging Detector

    NASA Astrophysics Data System (ADS)

    Torisky, Benjamin; Benmokhtar, Fatiha

    2015-04-01

    Jefferson Lab (Jlab) is performing a large-scale upgrade to their Continuous Electron Beam Accelerator Facility (CEBAF) up to 12 GeV beam. The Large Acceptance Spectrometer (CLAS12) in Hall B is being upgraded and a new Ring Imaging CHerenkov (RICH) detector is being developed to provide better kaon - pion separation throughout the 3 to 12 GeV range. With this addition, when the electron beam hits the target, the resulting pions, kaons, and other particles will pass through a wall of translucent aerogel tiles and create Cherenkov radiation. This light can then be accurately detected by a large array of Multi-Anode PhotoMultiplier Tubes (MA-PMT). I am presenting my work on the implementation of Java based reconstruction programs for the RICH in the CLAS12 main analysis package.

  3. Gas breakdown limits for inverse Cherenkov laser accelerators

    SciTech Connect

    Liu, Y.; Pogorelsky, I.V.

    1995-07-01

    The probability of avalanche, tunneling and multiphoton ionization induced by a CO{sub 2} laser in H{sub 2} gas has been calculated. Laser light screening by a self-induced plasma density gradient is considered as the limiting factor for upscaling a CO{sub 2} laser-driven Inverse Cherenkov Laser Accelerator beyond 650 MeV/m. However, in near-resonance inverse Cherenkov acceleration where a shorter wavelength laser is used at a wavelength near the resonance of the gas (e.g. 248nm in H{sub 2}), the formation of a plasma is not a problem because the plasma density is below the critical density. In that case, the laser beam propagates unaffected through the plasma and the acceleration gradient is not limited by gas breakdown. Gradients > 1 GeV/m are possible.

  4. Nonlinear saturation characteristics of a dielectric Cherenkov maser

    SciTech Connect

    Choi, J.S.; Heo, E.G.; Choi, D.I.

    1995-12-31

    The nonlinear saturation state in a dielectric Cherenkov maser (DCM) with the TM mode and the intense relativistic electron beam is analyzed from the nonlinear formulation based on the cold fluid-Maxwell equations. We obtain the nonlinear efficiency and the final operation frequency under consideration of the effects of the beam current, the beam energy and the dielectric materials and show that the characteristics of a DCM instablity has a strong resemblance to that of the relativistic two stream instability by the coherent trapping of electrons in a single most-ustable wave. Finally, the nonlinear analysis shows that the Cherenkov maser operation with a lower-energy beam can be more efficient in the higher frequency regime for the case of the high power DCM with a high current.

  5. G-APDs in Cherenkov astronomy: The FACT camera

    NASA Astrophysics Data System (ADS)

    Krähenbühl, T.; Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, V.; Djambazov, L.; Dorner, D.; Farnier, C.; Gendotti, A.; Grimm, O.; von Gunten, H.; Hildebrand, D.; Horisberger, U.; Huber, B.; Kim, K.-S.; Köhne, J.-H.; Krumm, B.; Lee, M.; Lenain, J.-P.; Lorenz, E.; Lustermann, W.; Lyard, E.; Mannheim, K.; Meharga, M.; Neise, D.; Nessi-Tedaldi, F.; Overkemping, A.-K.; Pauss, F.; Renker, D.; Rhode, W.; Ribordy, M.; Rohlfs, R.; Röser, U.; Stucki, J.-P.; Schneider, J.; Thaele, J.; Tibolla, O.; Viertel, G.; Vogler, P.; Walter, R.; Warda, K.; Weitzel, Q.

    2012-12-01

    Geiger-mode avalanche photodiodes (G-APD, SiPM) are a much discussed alternative to photomultiplier tubes in Cherenkov astronomy. The First G-APD Cherenkov Telescope (FACT) collaboration builds a camera based on a hexagonal array of 1440 G-APDs and has now finalized its construction phase. A light-collecting solid PMMA cone is glued to each G-APD to eliminate dead space between the G-APDs by increasing the active area, and to restrict the light collection angle of the sensor to the reflector area in order to reduce the amount of background light. The processing of the signals is integrated in the camera and includes the digitization using the domino ring sampling chip DRS4.

  6. Detection of Cherenkov Photons with Multi-Anode Photomultipliers

    SciTech Connect

    Salazar, H.; Moreno, E.; Murrieta, T.; Villasenor, L.

    2006-09-25

    The present paper describes the laboratory course given at the X Mexican Workshop on Particles and Fields. We describe the setup and procedure used to measure the Cherenkov circles produced by cosmic muons upon traversal of a simple glass radiator system. The main purpose of this exercise is to introduce the students to work with multi-anode photomultipliers such as the one used for this experiment (Hamamatsu R5900-M64), with which measurements requiring position sensitive detection of single photons can be successfully performed. We present a short introduction to multi-anode photomultipliers (MAPMT) and describe the setup and the procedure used to measure the response of a MAPMT to a uniform source of light. Finally, we describe the setup and procedure used to measure the Cherenkov circles produced by cosmic muons upon traversal of a simple glass radiator system.

  7. Modeling coherent cherenkov radio emissions from high energy electromagnetic showers.

    SciTech Connect

    Schoessow, P.

    1998-04-24

    A technique currently under study for the detection of ultrahigh energy cosmic ray neutrinos involves the measurement of radio emissions from the electromagnetic shower generated by the neutrino in a large volume of naturally occurring dielectric such as the Antarctic ice cap or salt domes. The formation of an electron excess in the shower leads to the emission of coherent Cherenkov radiation, an effect similar to the generation of wakefields in dielectric loaded structures. We have used the finite difference time domain (FDTD) wakefield code ARRAKIS to model coherent Cherenkov radiation fields from high energy showers; we present as an example calculations of expected signals in a proof of principle experiment proposed for the Fermilab Main Injector.

  8. Optical Cherenkov radiation in ultrafast cascaded second-harmonic generation

    NASA Astrophysics Data System (ADS)

    Bache, M.; Bang, O.; Zhou, B. B.; Moses, J.; Wise, F. W.

    2010-12-01

    We show through theory and numerics that when few-cycle femtosecond solitons are generated through cascaded (phase-mismatched) second-harmonic generation, these broadband solitons can emit optical Cherenkov radiation in the form of linear dispersive waves located in the red part of the spectrum. The beating between the dispersive wave and the soliton generates trailing temporal oscillations on the compressed soliton. Insertion of a simple short-wave pass filter after the crystal can restore a clean soliton. On the other hand, bandpass filtering around the dispersive wave peak results in near-transform-limited ultrashort mid-IR pulses with pulse durations much shorter than the input near-IR pulse. The Cherenkov radiation for the crystal considered (β-barium borate) is found for pump wavelengths in the range λ=0.95-1.45μm, and is located in the regime λ=1.5-3.5μm. For shorter pump wavelengths, the phase-matching point is located in the absorption region of the crystal, effectively absorbing the generated dispersive wave. By calculating the phase-matching curves for typically used frequency conversion crystals, we point out that the mid-IR absorption in the crystal in many cases automatically will filter away the dispersive wave. Finally, an investigation of recent experimental results uncovers a four-wave-mixing phenomenon related to Cherenkov radiation that is an additional generation mechanism of long-wavelength radiation that can occur during soliton compression. We discuss the conditions that lead to this alternative dynamics rather than generation of Cherenkov radiation.

  9. A Cherenkov viewing device for used-fuel verification

    NASA Astrophysics Data System (ADS)

    Attas, E. M.; Chen, J. D.; Young, G. J.

    1990-12-01

    A Cherenkov viewing device (CVD) has been developed to help verify declared inventories of used nuclear fuel stored in water bays. The device detects and amplifies the faint ultraviolet Cherenkov glow from the water surrounding the fuel, producing a real-time visible image on a phosphor screen. Quartz optics, a UV-pass filter and a microchannel-plate image-intensifier tube serve to form the image, which can be photographed or viewed directly through an eyepiece. Normal fuel bay lighting does not interfere with the Cherenkov light image. The CVD has been successfully used to detect anomalous PWR, BWR and CANDU (CANada Deuterium Uranium: registered trademark) fuel assemblies in the presence of normal-burnup assemblies stored in used-fuel bays. The latest version of the CVD, known as Mark IV, is being used by inspectors from the International Atomic Energy Agency for verification of light-water power-reactor fuel. Its design and operation are described, together with plans for further enhancements of the instrumentation.

  10. Position sensitive photon detectors for nuclear physics, particle physics and healthcare applications

    NASA Astrophysics Data System (ADS)

    Seitz, B.

    2012-01-01

    Modern experiments in hadronic physics require detector systems capable of identifying and reconstructing all final-state particles and their momentum vectors. Imaging Cherenkov counters (RICH and DIRC) are frequently employed in nuclear and particle physics experiments. These detectors require high-rate, single-photon capable light detection system with sufficient granularity and position resolution. Several candidate systems are available, ranging from multi-anode photomultiplier tubes to micro-channel plate systems to silicon photomultipliers. Each of these detection solutions has particular advantages and disadvantages. Detailed studies of rate dependence, cross-talk, time-resolution and position resolution for a range of available photon detection solutions are presented. These properties make these photon detection systems ideal for radionuclide imaging applications. Cherenkov radiation can also be used for medical imaging applications. Two different applications using the Cherenkov effect for radionuclide imaging will be reviewed.

  11. Report on the Construction, Deployment, and Measurement of the Spectra of Atmospheric Photons and Meteorological Parameters in the 0 to 1.8 MeV Regime Using a Wide-Area Array of Detectors.

    NASA Astrophysics Data System (ADS)

    Fasano, C. G.

    2015-12-01

    Measuring atmospheric photons under a wide array of atmospheric conditions may provide a new way to study a wide range of atmospheric conditions, including thunderstorms (TGE's), rain storms and snow storms. We report on the construction and deployment of detector packages that measure spectra, temperature, pressure, and relative humidity. Each standalone detector is mounted at rooftop level and measures and dumps photon spectra in the 0 to ~1.8 MeV regime every 10 minutes, and meterological parameters and overall photon count rate every 30 seconds. Using the precisely known positions and GPS timing of up to 10 detectors spread over western Illinois, eastern Iowa, and southern Wisconsin, we have measured atmospheric photon events in many different conditions, (including at least one tornadic storm). Our preliminary results demonstrate that a complex and changing background is present that must be characterized and understood before clear identification of TGEs and other high-energy photon events is possible. Our preliminary studies show photon events that occur on a variety of time scales, from rapid events that occur in periods of less than 30 seconds to events that last hours and show the spectral signature of the rainout of U-238 chain daughters. We present these events along with our initial attempts to understand and characterize these events and if/how they correlate with local meteorological conditions and lightning strike data from WWLLN. Finally we present what important experimental techniques we learned, our plans for upgrades and expansion of the detector array, and plans for future modeling activities to understand these data. We present how to access our expanding dataset online. This research is supported by a grant from the NSF: AGS-1232594

  12. A concept for the readout of multichannel detectors by using analog signal transmission via optical fibres coupled to a fast CCD

    NASA Astrophysics Data System (ADS)

    Mirzoyan, R.; Lorenz, E.; Rose, J.

    2000-06-01

    Recent developments in the field of electro-optical components allowed one to transform fast analog electrical signals into fast light pulses in a wide dynamic range and to send them via optical fibres over relatively long distances with very low time dispersion and amplitude losses. Here we propose to use the analog signal fibre transmission technique in combination with fast CCDs for the data acquisition of multichannel detectors as, for example, for the read out of imaging cameras of atmospheric Cherenkov telescopes. Hundreds of signal channels can be read out by using commercially available single CCD module in fast gated mode. The latter can provide high amplitude resolution and an acquisition rate of up to a few hundred Hz. Such a system can provide significantly lower costs compared to traditionally used amplitude digitizing systems. .

  13. Method for measuring changes in the atmospheric O2/N2 ratio by a gas chromatograph equipped with a thermal conductivity detector

    NASA Astrophysics Data System (ADS)

    Tohjima, Yasunori

    2000-06-01

    We present a method for measuring changes in the atmospheric O2/N2 ratio based on data from a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD). In this method, O2 and N2 in an air sample are separated on a column filled with molecular sieve 5A with H2 carrier gas. Since the separated O2 includes Ar, which has a retention time similar to that of O2, the (O2+Ar)/N2 ratio is actually measured. The change in the measured (O2+Ar)/N2 ratio can be easily converted to that in the O2/N2 ratio with a very small error based on the fact that the atmospheric Ar/N2 ratio is almost constant. The improvements to achieve the high-precision measurement include stabilization of the pressure at the GC column head and at the outlets of the TCD and the sample loop. Additionally, the precision is improved statistically by repeating alternate analyses of sample and a reference gas. The standard deviation of the replicate cycles of reference and sample analyses is about 18 per meg (corresponding to 3.8 parts per million (ppm) O2 in air). This means that the standard error is about 7 per meg (1.5 ppm O2 in air) for seven cycles of alternate analyses, which takes about 70 min. The response of this method is likely to have a 2% nonlinearity. Ambient air samples are collected under pressure in glass flasks equipped with two stopcocks sealed by Viton O-rings at both ends. Pressure depletion in the flask during the O2/N2 measurement does not cause any detectable change in the O2/N2 ratio, but the O2/N2 ratio in the flask was found to gradually decrease during the storage period. We also present preliminary results from air samples collected at Hateruma Island (latitude 24°03'N, longitude 123°49') from July 1997 through March 1999. The observed O2/N2 ratios clearly show a seasonal variation, increasing in spring and summer and decreasing in autumn and winter.

  14. IACT observations of gamma-ray bursts: prospects for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Gilmore, Rudy C.; Bouvier, Aurelien; Connaughton, Valerie; Goldstein, Adam; Otte, Nepomuk; Primack, Joel R.; Williams, David A.

    2013-04-01

    Gamma rays at rest frame energies as high as 90 GeV have been reported from gamma-ray bursts (GRBs) by the Fermi Large Area Telescope (LAT). There is considerable hope that a confirmed GRB detection will be possible with the upcoming Cherenkov Telescope Array (CTA), which will have a larger effective area and better low-energy sensitivity than current-generation imaging atmospheric Cherenkov telescopes (IACTs). To estimate the likelihood of such a detection, we have developed a phenomenological model for GRB emission between 1 GeV and 1 TeV that is motivated by the high-energy GRB detections of Fermi-LAT, and allows us to extrapolate the statistics of GRBs seen by lower energy instruments such as the Swift-BAT and BATSE on the Compton Gamma-ray Observatory. We show a number of statistics for detected GRBs, and describe how the detectability of GRBs with CTA could vary based on a number of parameters, such as the typical observation delay between the burst onset and the start of ground observations. We also consider the possibility of using GBM on Fermi as a finder of GRBs for rapid ground follow-up. While the uncertainty of GBM localization is problematic, the small field-of-view for IACTs can potentially be overcome by scanning over the GBM error region. Overall, our results indicate that CTA should be able to detect one GRB every 20-30 months with our baseline instrument model, assuming consistently rapid pursuit of GRB alerts, and provided that spectral breaks below ~100 GeV are not a common feature of the bright GRB population. With a more optimistic instrument model, the detection rate can be as high as 1 to 2 GRBs per year.

  15. Applications of Cherenkov Light Emission for Dosimetry in Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Glaser, Adam Kenneth

    Since its discovery in the 1930's, the Cherenkov effect has been paramount in the development of high-energy physics research. It results in light emission from charged particles traveling faster than the local speed of light in a dielectric medium. The ability of this emitted light to describe a charged particle's trajectory, energy, velocity, and mass has allowed scientists to study subatomic particles, detect neutrinos, and explore the properties of interstellar matter. However, only recently has the phenomenon been considered in the practical context of medical physics and radiation therapy dosimetry, where Cherenkov light is induced by clinical x-ray photon, electron, and proton beams. To investigate the relationship between this phenomenon and dose deposition, a Monte Carlo plug-in was developed within the Geant4 architecture for medically-oriented simulations (GAMOS) to simulate radiation-induced optical emission in biological media. Using this simulation framework, it was determined that Cherenkov light emission may be well suited for radiation dosimetry of clinically used x-ray photon beams. To advance this application, several novel techniques were implemented to realize the maximum potential of the signal, such as time-gating for maximizing the signal to noise ratio (SNR) and Cherenkov-excited fluorescence for generating isotropic light release in water. Proof of concept experiments were conducted in water tanks to demonstrate the feasibility of the proposed method for two-dimensional (2D) projection imaging, three-dimensional (3D) parallel beam tomography, large field of view 3D cone beam tomography, and video-rate dynamic imaging of treatment plans for a number of common radiotherapy applications. The proposed dosimetry method was found to have a number of unique advantages, including but not limited to its non-invasive nature, water-equivalence, speed, high-resolution, ability to provide full 3D data, and potential to yield data in-vivo. Based on

  16. The RICH detector for CLAS12 at Jefferson Lab

    SciTech Connect

    Pappalardo, Luciano L.

    2014-06-01

    The CLAS12 spectrometer at JLab will offer unique possibilities to study the 3D nucleon structure in terms of TMDs and GPDs in the poorly explored valence region, and to perform high precision hadron spectroscopy. A large area ring-imaging Cherenkov detector has been designed to achieve the required hadron identification capability in the momentum range 3-8 GeV/c. The detector, based on a novel hybrid imaging design, foresees an aerogel radiator and an array of multi-anode photomultipliers. The detector concept and preliminary results of test-beams on a prototype are presented.

  17. Automated radioanalytical system for the determination of 90Sr in environmental water samples by 90Y Cherenkov radiation counting.

    PubMed

    O'Hara, Matthew J; Burge, Scott R; Grate, Jay W

    2009-02-01

    Strontium-90 is an environmental contaminant at several U.S. Department of Energy sites, including the Hanford site, Washington. Due to its high biological toxicity and moderately long half-life of approximately 29 years, groundwater and surface water contamination plumes containing 90Sr must be closely monitored. The highly energetic beta radiation from the short-lived 90Y daughter of 90Sr generates Cherenkov photons in aqueous media that can be detected by photomultiplier tubes with good sensitivity, without the use of scintillation cocktails. A laboratory-based automated fluid handling system coupled to a Cherenkov radiation detector for measuring 90Sr via the high-energy beta decay of its daughter, 90Y, has been assembled and tested using standards prepared in Hanford groundwater. A SuperLig 620 column in the system enables preconcentration and separation of 90Sr from matrix and radiological interferences and, by removing the 90Y present in the sample, creates a pure 90Sr source from which subsequent 90Y ingrowth can be measured. This 90Y is fluidically transferred from the column to the Cherenkov detection flow cell for quantification and calculation of the original 90Sr concentration. Preconcentrating 0.35 L sample volumes by this approach, we have demonstrated a detection limit of 0.057 Bq/L using a 5 mL volume Cherenkov flow cell, which is below the drinking water limit of 0.30 Bq/L. This method does not require that the sample be at secular equilibrium prior to measurement. The system can also deliver water samples directly to the counting cell for analysis without preconcentration or separation, assuming that the sample is in secular equilibrium, with a detection limit of 7 Bq/L. The performance of the analysis method using a preconcentrating separation column is characterized in detail and compared with direct counting. This method is proposed as the basis for an automated fluidic monitor for 90Sr for unattended at-site operation.

  18. Atmospheric Effects on Cosmic Ray Air Showers Observed with HAWC

    NASA Astrophysics Data System (ADS)

    Young, Steven

    2014-01-01

    The High Altitude Water Cherenkov Gamma Ray detector (HAWC), currently under construction on the Sierra Negra volcano near Puebla, Mexico, can be used to study solar physics with its scaler data acquisition system. Increases in the scaler rates are used to observe GeV cosmic rays from solar flares while decreases in the rates show the heliospheric disturbances associated with coronal mass ejections. However, weather conditions and height-dependent state variables such as pressure and temperature affect the production of extensive particle air showers that can be detected by the scaler system. To see if these atmospheric effects can be removed, we obtained local weather data from the Global Data Assimilation System (GDAS) and the local weather station at HAWC. The scaler pulse rates were then correlated to the pressure and temperature. We present data from a Forbush decrease observed by HAWC following a significant coronal mass ejection in April 2013, and describe our efforts to remove atmospheric variations from the scaler counts. This work was partially supported by the National Science Foundation’s REU program through NSF Award AST-1004881 to the University of Wisconsin-Madison.

  19. Characterization of a 6×6-mm2 75-μm cell MPPC suitable for the Cherenkov Telescope Array project

    NASA Astrophysics Data System (ADS)

    Romeo, G.; Bonanno, G.; Garozzo, S.; Grillo, A.; Marano, D.; Munari, M.; Timpanaro, M. C.; Catalano, O.; Giarrusso, S.; Impiombato, D.; La Rosa, G.; Sottile, G.

    2016-08-01

    This paper presents the latest characterization results of a novel Low Cross-Talk (LCT) large-area (6×6-mm2) Multi-Pixel Photon Counter (MPPC) detector manufactured by Hamamatsu, belonging to the recent LCT5 family and achieving a fill-factor enhancement and cross-talk reduction. In addition, the newly adopted resin coating is demonstrated to yield improved photon detection capabilities in the 290-350 nm spectral range, making the new LCT MPPC particularly suitable for emerging applications like Cherenkov Telescopes. For a 3×3-mm2 version of the new MPPC under test, a comparative analysis of the large pixel pitch (75-μm) detector versus the smaller pixel pitch (50-μm) detector is also undertaken. Furthermore, measurements of the 6×6-mm2 MPPC response versus the angle of incidence are provided for the characterized device.

  20. Determining neutrino oscillation parameters from atmospheric muon neutrino disappearance with three years of IceCube DeepCore data

    NASA Astrophysics Data System (ADS)

    Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Altmann, D.; Anderson, T.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Brayeur, L.; Bretz, H.-P.; Brown, A. M.; Brunner, J.; Buzinsky, N.; Casey, J.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Christy, B.; Clark, K.; Classen, L.; Clevermann, F.; Coenders, S.; Cowen, D. F.; Cruz Silva, A. H.; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; Dunkman, M.; Eagan, R.; Eberhardt, B.; Eichmann, B.; Eisch, J.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Felde, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Franckowiak, A.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gaior, R.; Gallagher, J.; Gerhardt, L.; Gier, D.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Goodman, J. A.; Góra, D.; Grant, D.; Gretskov, P.; Groh, J. C.; Groß, A.; Ha, C.; Haack, C.; Haj Ismail, A.; Hallen, P.; Hallgren, A.; Halzen, F.; Hanson, K.; Hebecker, D.; Heereman, D.; Heinen, D.; Helbing, K.; Hellauer, R.; Hellwig, D.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huang, F.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Jagielski, K.; Japaridze, G. S.; Jero, K.; Jlelati, O.; Jurkovic, M.; Kaminsky, B.; Kappes, A.; Karg, T.; Karle, A.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kheirandish, A.; Kiryluk, J.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Koob, A.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Kriesten, A.; Krings, K.; Kroll, G.; Kroll, M.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Lanfranchi, J. L.; Larsen, D. T.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Lünemann, J.; Madsen, J.; Maggi, G.; Maruyama, R.; Mase, K.; Matis, H. S.; Maunu, R.; McNally, F.; Meagher, K.; Medici, M.; Meli, A.; Meures, T.; Miarecki, S.; Middell, E.; Middlemas, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Paul, L.; Penek, Ö.; Pepper, J. A.; Pérez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Pütz, J.; Quinnan, M.; Rädel, L.; Rameez, M.; Rawlins, K.; Redl, P.; Rees, I.; Reimann, R.; Relich, M.; Resconi, E.; Rhode, W.; Richman, M.; Riedel, B.; Robertson, S.; Rodrigues, J. P.; Rongen, M.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Sander, H.-G.; Sandroos, J.; Santander, M.; Sarkar, S.; Schatto, K.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Sestayo, Y.; Seunarine, S.; Shanidze, R.; Smith, M. W. E.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stanisha, N. A.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Terliuk, A.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Tosi, D.; Tselengidou, M.; Unger, E.; Usner, M.; Vallecorsa, S.; van Eijndhoven, N.; Vandenbroucke, J.; van Santen, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Wallraff, M.; Weaver, Ch.; Wellons, M.; Wendt, C.; Westerhoff, S.; Whelan, B. J.; Whitehorn, N.; Wichary, C.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Ziemann, J.; Zierke, S.; Zoll, M.; IceCube Collaboration

    2015-04-01

    We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser IceCube instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10 and 100 GeV, where a strong disappearance signal is expected. The IceCube detector volume surrounding DeepCore is used as a veto region to suppress the atmospheric muon background. Neutrino events are selected where the detected Cherenkov photons of the secondary particles minimally scatter, and the neutrino energy and arrival direction are reconstructed. Both variables are used to obtain the neutrino oscillation parameters from the data, with the best fit given by Δ m322=2.72-0.20+0.19×10-3 eV2 and sin2θ23=0.53-0.12+0.09 (normal mass ordering assumed). The results are compatible, and comparable in precision, to those of dedicated oscillation experiments.

  1. Restoration of parameters of high-energy cascades in Cherenkov water calorimeter with a dense array of quasispherical modules

    SciTech Connect

    Khomyakov, V. A. Bogdanov, A. G.; Kindin, V. V.; Kokoulin, R. P.; Petrukhin, A. A.; Khokhlov, S. S.; Shutenko, V. V.; Yashin, I. I.

    2015-12-15

    A problem concerning the restoration of the parameters of a cascade shower with an unknown axis originating by muons in a Cherenkov water calorimeter is considered. A method for estimating the direction and geometric position of the cascade’s axis, which is based on the analysis of responses of quasispherical modules, and the criteria of selection of the events with cascades among the events with a large energy liberation are proposed. The method and the criteria are tested on events with cascades generated by near-horizontal muons of high energies detected by a DECOR coordinate-track detector. The preliminary results of measurements of the energy spectrum of cascade showers are presented.

  2. Design constraints on Cherenkov telescopes with Davies-Cotton reflectors

    NASA Astrophysics Data System (ADS)

    Bretz, T.; Ribordy, M.

    2013-05-01

    This paper discusses the construction of high-performance ground-based gamma-ray Cherenkov telescopes with a Davies-Cotton reflector. For the design of such telescopes, usually physics constrains the field-of-view, while the photo-sensor size is defined by limited options. Including the effect of light-concentrators, it is demonstrated that these constraints are enough to mutually constrain all other design parameters. The dependability of the various design parameters naturally arises once a relationship between the value of the point-spread functions at the edge of the field-of-view and the pixel field-of-view is introduced. To be able to include this constraint into a system of equations, an analytical description for the point-spread function of a tessellated Davies-Cotton reflector is derived from Taylor developments and ray-tracing simulations. Including higher order terms renders the result precise on the percent level. Design curves are provided within the typical phase space of Cherenkov telescopes. The impact of all design parameters on the overall design is discussed. Allowing an immediate comparison of several options with identical physics performance allows the determination of the most cost efficient solution. Emphasis is given on the possible application of solid light concentrators with their typically about two times better concentration compared with hollow cones which allows the use of small photo sensors such as Geiger-mode avalanche photo diodes. This is discussed in more details in the context of possible design options for the Cherenkov Telescope Array. In particular, a solution for a 60 mm2 photo sensor with hollow cone is compared to a 36 mm2 with solid cone.

  3. Report on the Depth Requirements for a Massive Detector at Homestake

    SciTech Connect

    Bernstein,A.; Blucher, E.; Cline, D. B.; Diwan, M. V.; Fleming, b.; Kadel, R.; Kearns, E.; Klein, J.; Lande, K.; Lanni, F.; Lissauer, D.; McKeown, R.; Morse, W.; Radeika, R.; Scholberg, K.; Smy, M.; Sobel, H.; Sullivan, G.; Svoboda, R.; Vagins, M.; Walter, C.; Zwaska, R.

    2008-12-22

    This report provides the technical justification for locating a large detector underground in a US based Deep Underground Science and Engineering Laboratory. A large detector with a fiducial mass greater than 100 kTon will most likely be a multipurpose facility. The main physics justification for such a device is detection of accelerator generated neutrinos, nucleon decay, and natural sources of neutrinos such as solar, atmospheric and supernova neutrinos. The requirement on the depth of this detector will be guided by the rate of signals from these sources and the rate of backgrounds from cosmic rays over a very wide range of energies (from solar neutrino energies of 5 MeV to high energies in the range of tens of GeV). For the present report, we have examined the depth requirement for a large water Cherenkov detector and a liquid argon time projection chamber. There has been extensive previous experience with underground water Cherenkov detectors such as IMB, Kamioka, and most recently, Super-Kamiokande which has a fiducial mass of 22 kTon and a total mass of 50 kTon at a depth of 2700 meters-water-equivalent. Projections for signal and background capability for a larger and deeper (or shallower) detectors of this type can be scaled from these previous detectors. The liquid argon time projection chamber has the advantage of being a very fine-grained tracking detector, which provides enhanced capability for background rejection. In the current work we have taken the approach that the depth should be sufficient to suppress the cosmogenic background below predicted signal rates for either of the above two technologies. Nevertheless, it is also clear that the underground facility that we are examining must have a long life and will most likely be used either for future novel uses of the currently planned detectors or new technologies. Therefore the depth requirement also needs to be made on the basis of sound judgment regarding possible future use. In particular, the

  4. Report on the Depth Requirements for a Massive Detector at Homestake

    SciTech Connect

    Kadel, Richard W.; Bernstein, Adam; Blucher, Edward; Cline, David B.; Diwan, Milind V.; Fleming, Bonnie; Kearns, Edward; Klein, Joshua; Lande, Kenneth; Lanni, Francesco; Lissauer, David; McKeown, Robert; Morse, William; Rameika, Regina; Scholberg, Kate; Smy, Michael; Sobel, Henry; Sullivan, Gregory; Svoboda, Robert; Vagins, Mark; Walter, Christopher; Zwaska, Robert

    2008-12-23

    This report provides the technical justification for locating a large detector underground in a US based Deep Underground Science and Engineering Laboratory. A large detector with a fiducial mass greater than 100 kTon will most likely be a multipurpose facility. The main physics justification for such a device is detection of accelerator generated neutrinos, nucleon decay, and natural sources of neutrinos such as solar, atmospheric and supernova neutrinos. The requirement on the depth of this detector will be guided by the rate of signals from these sources and the rate of backgrounds from cosmic rays over a very wide range of energies (from solar neutrino energies of 5 MeV to high energies in the range of hundreds of GeV). For the present report, we have examined the depth requirement for a large water Cherenkov detector and a liquid argon time projection chamber. There has been extensive previous experience with underground water Cherenkov detectors such as IMB, Kamioka, and most recently, Super-Kamiokande which has a fiducial mass of 22 kTon and a total mass of 50 kTon at a depth of 2700 meters-water-equivalent in a mountain. Projections for signal and background capability for a larger and deeper(or shallower) detectors of this type can be scaled from these previous detectors. The liquid argon time projection chamber has the advantage of being a very fine-grained tracking detector, which should provide enhanced capability for background rejection. We have based background rejection on reasonable estimates of track and energy resolution, and in some cases scaled background rates from measurements in water. In the current work we have taken the approach that the depth should be sufficient to suppress the cosmogenic background below predicted signal rates for either of the above two technologies. Nevertheless, it is also clear that the underground facility that we are examining must have a long life and will most likely be used either for future novel uses of the

  5. Construction and testing of the SLD Cerenkov ring imaging detector

    SciTech Connect

    Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Williams, D.A. . Inst. for Particle Physics); Zucchelli, P. . Ist. di Fisica); Jacques, P.; Piano, R.; Stamer, P. . Serin Physics Lab.); Whitaker, J.S.; Wilson, R.J. . Dept. of Physics); Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; HcHugh, S.; Morrison, R.; Witherell, M.; Yellin, S. . Dept. of Physics); Antiligus, P.; Aston, D.; Bienz, T.; Bird, F.; Dosu, S.; Dunwoodie, W.; Hallewell, B.; Kawahara, H.; Kwon, Y.; Leith, D.; Muller, D.; Nagamine, T.; Pavel, T.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Valvre, J.; Williams, S. ); Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H. . Dept. of Physics)

    1990-06-01

    The authors report on the construction of the Cherenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider and the testing of its components. The authors include results from testing the drift boxes, liquid radiator trays, and mirrors for the barrel CRID. The authors also discuss development of the support systems essential for the operation of the CRID: gas and liquid recirculator systems and monitoring.

  6. Cosmic ray studies with a gas Cherenkov counter in association with an ionization spectrometer

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V. K.; Ormes, J. F.; Arens, J. F.; Siohan, F.; Yodh, G. B.; Simon, M.; Spiegelhauer, H.

    1980-01-01

    The results from a balloon-borne gas Cherenkov counter (threshold 16.5 GeV/nucleon) and an ionization spectrometer are presented. The gas Cherenkov counter provides an absolute energy distribution for the response of the calorimeter for 5 or = Z 26 nuclei of cosmic rays. The contribution of scintillation to the gas Cherenkov pulse height was obtained by independently selecting particles below the gas Cherenkov threshold using the ionization spectrometer. Energy spectra were derived by minimizing the chi squared between Monte Carlo simulted data and flight data. Best fit power laws, dN/dE = AE-gamma, were determined for C, N, O, Ne, Mg, and Si. The power laws, all consistent with E (-2.7) are not good fits to the data. A better fit is obtained using the spectrum derived from the spectrometer. The data from the ionization calorimeter and the gas Cherenkov are thus completely self-consistent.

  7. Electron waves resonance properties in superdimensional microwave Cherenkov devices

    SciTech Connect

    Chernyavsky, I.A.; Pikunov, V.M.

    1995-11-01

    The electron waves resonance properties in the one-stage and two-stage microwave Cherenkov devices based on the superdimensional slow-wave structures are investigated by the linear theory methods near {pi}-cutoff of E{sub 01} waveguide mode. The variation of the generation frequencies and it`s starting currents, when diode voltage changes in a wide range of value, are investigated. concept of a longitudinal electron oscillations (LEO) is defined for a one-stage device. The dependencies of the generation frequency and starting current versus the drift tube length are investigated for the two-stage device in detail.

  8. Multimode terahertz-wave generation using coherent Cherenkov radiation

    SciTech Connect

    Kan, K.; Yang, J.; Ogata, A.; Kondoh, T.; Norizawa, K.; Yoshida, Y.

    2011-12-05

    Multimode terahertz(THz)-wave generation using coherent Cherenkov radiation (CCR) was investigated. The frequency spectra of CCR, which utilized a metal-wrapped hollow dielectric tube of 7 mm outer radius and a picosecond electron bunch of 27 MeV beam energy, were measured by a Michelson interferometer with a 4.2 K silicon bolometer. In this study, discrete spectral components at frequencies of 0.09, 0.14, and 0.36 THz were observed experimentally and explained as transverse magnetic (TM) modes of TM{sub 03}, TM{sub 04}, and TM{sub 09}, respectively, according to a theoretical calculation for the tube.

  9. Corrugated capillary as THz Cherenkov Smith-Purcell radiator

    NASA Astrophysics Data System (ADS)

    Lekomtsev, K. V.; Aryshev, A. S.; Tishchenko, A. A.; Ponomarenko, A. A.; Sukharev, V. M.; Terunuma, N.; Urakawa, J.; Strikhanov, M. N.

    2016-07-01

    In this article we discussed Particle In Cell electromagnetic simulations and mechanical design of dielectric capillaries that produce THz Cherenkov Smith-Purcell radiation (ChSPR), arising when a femtosecond electron multi-bunch beam propagates through corrugated and non-corrugated dielectric capillaries with metallic radiation reflectors. We investigated the influence of the four-bunch beam on the SPR field spectrum and on the ChSPR power spectrum, and the influence of the non-central beam propagation on the ChSPR power spectrum. We also discussed the design and assembly of the capillaries, constructed as sets of cylindrical rings.

  10. Modified energy-momentum conservation laws and vacuum Cherenkov radiation

    NASA Astrophysics Data System (ADS)

    Carmona, J. M.; Cortés, J. L.; Romeo, B.

    2015-12-01

    We present a general parametrization for the leading order terms in a momentum power expansion of a non-universal Lorentz-violating, but rotational invariant, kinematics and its implications for two-body decay thresholds. The considered framework includes not only modified dispersion relations for particles, but also modified energy-momentum conservation laws, something which goes beyond effective field theory. As a particular and relevant example, bounds on the departures from special relativistic kinematics from the non-observation of vacuum Cherenkov radiation are discussed and compared with those obtained within the effective field theory scenario.

  11. FACT - The first G-APD Cherenkov telescope (first results)

    NASA Astrophysics Data System (ADS)

    Bretz, T.; Dorner, D.; Backes, M.; Biland, A.; Buß, J.; Commichau, V.; Djambazov, L.; Eisenacher, D.; Grimm, O.; von Gunten, H.; Hildebrand, D.; Krähenbühl, T.; Lustermann, W.; Lyard, E.; Mannheim, K.; Neise, D.; Overkemping, A.-K.; Paravac, A.; Pauss, F.; Rhode, W.; Ribordy, M.; Röser, U.; Stucki, J.-P.; Temme, F.; Thaele, J.; Tobler, S.; Vogler, P.; Walter, R.; Weitzel, Q.; Zänglein, M.

    2012-12-01

    In October 2011, the first air-Cherenkov telescope utilizing Geiger-mode avalanche photodiodes commenced operations. The silicon-based devices display several advantages compared to classical photomultiplier tubes allowing for a more compact camera design of higher reliability, lower power consumption and bias voltage, and better prospects for improving the photon detection efficiency. Here, the first physics results are presented from a few months of data taking. Although still preliminary, the results already show a superb fidelity of the data, demonstrating the potential of avalanche photodiodes for ground-based gamma ray astronomy. The stability and high sensitivity are ideal for remote monitoring observations of variable gamma-ray sources.

  12. Performance of ZnSe(Te) as fiberoptic dosimetry detector.

    PubMed

    Ramírez, M; Martínez, N; Marcazzó, J; Molina, P; Feld, D; Santiago, M

    2016-10-01

    Fiberoptic dosimetry (FOD) is an experimental technique suitable for in-vivo, real time dosimetry in radiotherapy treatments. FOD relies on using a small scintillator coupled to one end of a long optical fiber. The scintillator is placed at the point where the dose rate is to be determined whereas a light detector at the other end of the fiber measures the intensity of the radioluminescence emitted by the scintillator. One of the problems hampering the straightforward application of this technique in clinics is the presence of Cherenkov radiation generated in the fiber by the ionizing radiation, which adds to the scintillating light and introduces a bias in the dose measurement. Since Cherenkov radiation is more important in short wavelength range of the visible spectrum, using red-emitting scintillators as FOD detectors permits to reduce the Cherenkov contribution by using optical filters. In this work, the performance of red-emitting tellurium-doped zinc selenide crystal as FOD detector is evaluated and compared to the response of an ion-chamber. PMID:27472824

  13. A gas-RICH detector for space

    NASA Astrophysics Data System (ADS)

    Francke, T.; Bergström, D.; Boezio, M.; Carlson, P.; Suffert, M.

    1999-08-01

    A gas-RICH counter using a C4F10 radiator and pad readout has been developed. The good transmission of the optical elements together with a low noise level in the electronics results that on average 12 photoelectrons are detected per event for /Z=1 particles with /β~1. The reconstructed Cherenkov angle has a resolution of 1.2mrad. The RICH detector is an important part of a balloon borne experiment, CAPRICE, which measures the flux of antiprotons and positrons in the cosmic radiation.

  14. Development of novel designs of spark-protected micropattern gaseous detectors with resistive electrodes

    NASA Astrophysics Data System (ADS)

    Peskov, V.; Martinengo, P.; Nappi, E.; Oliveira, R.; Pietropaolo, P.; Picchi, P.

    2012-01-01

    In the last few years many efforts have been made by various groups to develop spark-protected micropattern gaseous detectors equipped with resistive electrodes instead of metallic ones. Great success has recently been achieved with resistive gas electron multipliers (GEMs), resistive micromesh gaseous structures and resistive Well/compteur a trou detectors. In this paper, we will focus on the development of a new family of spark-protected micropattern detectors: the 2D sensitive resistive microstrip counter and the resistive microhole and strip plate, which combines in one design a resistive GEM with a microstrip detector. These innovative detectors are manufactured on standard printed circuit boards by using a simple technology thus reducing the production cost. These novel detectors have several important advantages over other micropattern detectors and are unique for applications like the readout detectors for dual phase noble liquid time projection chambers and ring imaging Cherenkov detectors.

  15. Preliminary Design of the Gas Cherenkov Muon Monitors for LBNE

    NASA Astrophysics Data System (ADS)

    Pitcher, Craig

    2011-10-01

    I am performing preliminary research for a future neutrino experiment at Fermilab called the Long Baseline Neutrino Experiment (LBNE). More specifically, I am determining the best geometry for the gas Cherenkov muon monitors. The purpose of the monitors is to measure, at least indirectly, the energy spectrum of the muons in the beam. I use computer software to simulate a realistic muon beam going through the monitors. Muons in the particle beam that go through the monitors emit Cherenkov radiation, and this light is detected by PMTs. I then plot the number of photons detected as a function of the muon's energy that emitted the detected photons. My goal is to have a very narrow peak on this plot. This peak shifts depending on the simulated index of refraction. The best design for the monitors is an L-shaped pipe filled with Freon gas of adjustable density. It is the simplest and cheapest to build of all the designs I tried, and it can accurately recover the muon energy spectrum based solely on the total number of photons detected in each pulse: using simulation data from 5 indices of refraction, I can recover the muon energy spectrum (within the uncertainties) of a beam that has 5 discrete muon energies.

  16. Measurement of charged hadron spectra at the Z{sup 0} with Cherenkov ring imaging

    SciTech Connect

    Pavel, T.

    1997-08-01

    This dissertation attempts to probe hadronization, the process by which the fundamental quarks described by quantum chromodynamics produce the jets of hadrons that the author observed in experiments. The measurements are made using e{sup +}e{sup -} collisions at the SLAC Linear Collider (SLC), operating at the Z{sup 0} resonance with the SLC Large Detector (SLD), and the unique capabilities of the SLC/SLD facility are exploited. First, the spectra of charged hadrons ({pi}{sup {+-}}, K{sup {+-}}, and p/{bar p}) are measured. This is accomplished with the SLD Cherenkov Ring Imaging Detector (CRID), one of a first generation of devices that have been developed for efficient particle identification over a wide momentum range. The use of the CRID is central to this dissertation, and its design and performance are described in detail here. The measured spectra agree with other measurements at the Z{sup 0} and extend the momentum coverage. Next, the excellent spatial resolution of the SLD tracking systems, along with the small and stable beam spots of the SLC, is employed to identify jets produced from heavy b or c quarks and to separate them from the remaining light-quark (uds) jets. This removes the effects of heavy quark fragmentation and decays of heavy-quark hadrons from the study of hadronization. The first measurements of particle spectra in light-quark jets are then presented. Finally, the highly-polarized incident electron beam of the SLC, together with the electroweak asymmetries of the quarks, is exploited to separate quark and antiquark jets. Significant differences in quark-antiquark production of protons and of kaons are observed at high momenta. This signal suggests a leading particle effect, where the particles containing the primary quark of a jet are more likely to populate the high-momentum phase space than are other hadrons.

  17. Development of Yangbajing air shower core detector for a new EAS hybrid experiment

    NASA Astrophysics Data System (ADS)

    Liu, Jin-Sheng; Huang, Jing; Chen, Ding; Zhang, Ying; Zhai, Liu-Ming; Chen, Xu; Hu, Xiao-Bin; Lin, Yu-Hui; Zhang, Xue-Yao; Feng, Cun-Feng; Jia, Huan-Yu; Zhou, Xun-Xiu; Danzengluobu; Chen, Tian-Lu; Li, Hai-Jin; Liu, Mao-Yuan; Yuan, Ai-Fang

    2015-08-01

    Aiming at the observation of cosmic-ray chemical composition in the “knee” energy region, we have been developing a new type of air-shower core detector (YAC, Yangbajing Air shower Core detector array) to be set up at Yangbajing (90.522° E, 30.102° N, 4300 m above sea level, atmospheric depth: 606 g/m2) in Tibet, China. YAC works together with the Tibet air-shower array (Tibet-III) and an underground water Cherenkov muon detector array (MD) as a hybrid experiment. Each YAC detector unit consists of lead plates of 3.5 cm thickness and a scintillation counter which detects the burst size induced by high energy particles in the air-shower cores. The burst size can be measured from 1 MIP (Minimum Ionization Particle) to 106 MIPs. The first phase of this experiment, named “YAC- I”, consists of 16 YAC detectors each with a size of 40 cm×50 cm and distributed in a grid with an effective area of 10 m2. YAC- I is used to check hadronic interaction models. The second phase of the experiment, called “YAC- II”, consists of 124 YAC detectors with coverage of about 500 m2. The inner 100 detectors of 80 cm×50 cm each are deployed in a 10×10 matrix with a 1.9 m separation; the outer 24 detectors of 100 cm×50 cm each are distributed around these to reject non-core events whose shower cores are far from the YAC- II array. YAC- II is used to study the primary cosmic-ray composition, in particular, to obtain the energy spectra of protons, helium and iron nuclei between 5×1013 eV and 1016 eV, covering the “knee” and also connected with direct observations at energies around 100 TeV. We present the design and performance of YAC- II in this paper. Supported by grants from the National Natural Science Foundation of China (11078002, 11275212, 11165013), the Chinese Academy of Sciences (H9291450S3, Y4293211S5) and the Knowledge Innovation Fund of Institute of High Energy Physics (IHEP), China (H95451D0U2, H8515530U1)

  18. The PHENIX Hadron Blind Detector

    SciTech Connect

    Durham, J. M.

    2009-03-10

    Dielectron measurements by the PHENIX Experiment at RHIC are limited by the combinatorial background from electrons and positrons which are not produced in the same pair. The Hadron Blind Detector will allow a substantial reduction of this background by correctly identifying dielectrons from photon conversions and pion Dalitz decays which dominate the signal in the low mass region of the spectrum. Triple GEM stacks, with a CsI photocathode deposited on the uppermost GEM, detect Cherenkov light produced by electrons in a CF{sub 4} radiator. The transparency of CF{sub 4}, high quantum efficiency of CsI in the UV, and absence of a window between the gas radiator and the GEMs allow a large photoelectron yield, while minimizing the hadron signal. Results from the HBD in RHIC's Run-7 and preparations for upcoming runs are discussed.

  19. Design, construction, operation and performance of a Hadron Blind Detector for the PHENIX experiment

    SciTech Connect

    Anderson, W.; Azmoun, B.; Cherlin, A.; Chi, C.Y.; Citron, Z.; Connors, M.; Dubey, A.; Durham, J.M.; Fraenkel, Z.; Hemmick, T.; Kamin, J.; Kozlov, A.; Lewis, B.; Makek, M.; Milov, A.; Naglis, M.; Pantuev, V.; Pisani, R.; Proissl, M.; Ravinovich, I.; Rolnick, S.; Sakaguchi, T.; Sharma, D.; Stoll, S.; Sun, J.; Tserruya, I.; Woody, C.

    2011-04-15

    A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure CF{sub 4}. It has a 50 cm long radiator directly coupled in a windowless configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.

  20. The Non-Imaging CHErenkov Array (NICHE): A TA/TALE extension to measure the flux and composition of Very-High Energy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Bergman, Douglas; Krizmanic, John; Sokolsky, Pierre

    2013-04-01

    Co-sited with TA/TALE, the Non-Imaging CHErenkov Array (NICHE) will measure the flux and nuclear composition of cosmic rays from below 10^16 eV to over 10^18 eV in its initial deployment. Furthermore, the low-energy reach can be lowered below the cosmic ray knee via counter redeployment or additional counters. NICHE uses easily deployable detectors to measure the amplitude and time-spread of the air-shower Cherenkov signal to achieve an event-by-event measurement of Xmax and energy, each with excellent resolution. NICHE will have sufficient area and angular acceptance to have significant overlap with the TA/TALE detectors to allow for energy cross-calibration. Simulated NICHE performance has shown that the array has the ability to distinguish between several different composition models as well as measure the end of Galactic cosmic ray spectrum. In this talk, the NICHE design, array performance, and status will be discussed as well as NICHE's ability to measure the cosmic ray nuclear composition as a function of energy.

  1. The Non-Imaging CHErenkov (NICHE) Array: A TA/TALE extension to measure the flux and composition evolution of Very-High Energy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Krizmanic, John; Bergman, Douglas; Tsunesada, Yoshiki

    2015-04-01

    Co-sited with TA/TALE, the Non-Imaging CHErenkov (NICHE) Array will measure the flux and nuclear composition of cosmic rays from below 1015 eV to over 1018 eV in its eventual full deployment. NICHE uses easily deployable detectors to measure the amplitude and time-spread of the air-shower Cherenkov signal to achieve an event-by-event measurement of Xmax and energy, each with excellent resolution. Prototype detectors are under construction and will form an initial prototype array (jNICHE) that will be deployed in 2015, co-measuring air showers with TA/TALE. This development forms the foundation for the full NICHE array that is designed to have sufficient area and angular acceptance to have significant overlap with the TA/TALE measurements, which provides energy cross-calibration. Simulated NICHE performance has shown that the array has the ability to distinguish between several different composition models as well as measure the end of Galactic cosmic ray spectrum. In this talk, the NICHE design, array performance, prototype development, and status will be discussed as well as NICHE's ability to measure the cosmic ray nuclear composition as a function of energy.

  2. Quartz Detector Development for PVeS Experiments

    NASA Astrophysics Data System (ADS)

    Bula Villarreal, Carlos

    2016-03-01

    The high luminosity requirements of Parity Violating electron Scattering (PVeS) experiments, such as Jefferson Lab's PREX, CREX and MOLLER, create several challenges for detector design. The main ''integrating'' detectors for these experiments must intercept and precisely count scattered electron fluxes at GHz rates over prolonged periods of time. The detector's active (Cherenkov) medium has been chosen to be high-purity, fused silica (Spectrosil 2000) quartz-which is known to maintain deep UV transparency during extreme radiation doses. Several detector prototypes have been built at Idaho State University and tested using the 850 MeV electron test-beam at the Mainz Microtron (MAMI). To aid in prototype development, an optical G4 Monte Carlo has been developed and now benchmarked using the real MAMI data. This talk will present some physics motivations, the PREX/CREX prototype detector designs, and their test-beam performance with comparisons to simulation.

  3. Constraints on Extragalactic Background Light from Cherenkov telescopes: status and perspectives for the next 5 years

    SciTech Connect

    Mazin, Daniel

    2009-04-08

    Very high energy (VHE, E>30 GeV){gamma}-rays are absorbed via interaction with low-energy photons from the extragalactic background light (EBL) if the involved photon energies are above the threshold for electron-positron pair creation. The VHE {gamma}-ray absorption, which is energy dependent and increases strongly with redshift, distorts the VHE energy spectra observed from distant objects. The observed energy spectra of the AGNs carry therefore an imprint of the EBL. Recent detections of hard spectra of distant blazars (z = 0.11-0.54) by H.E.S.S. and MAGIC put strong constraints on the EBL density in the optical to near infrared waveband. It is, however, not yet possible to distinguish between an intrinsic softening of blazar spectra and a softening caused by the interaction with low energy EBL photons. In this paper, we give an overview of the EBL constraints, their limitations and perspectives for the joint efforts of the Fermi Gamma-Ray Space telescope and imaging atmospheric Cherenkov telescopes.

  4. Status of Coherent Cherenkov Wakefield Experiment at UCLA

    SciTech Connect

    Cook, A. M.; Knyazik, A.; Rosenzweig, J. B.; Tikhoplav, R.; Travish, G.; Williams, O. B.

    2009-01-22

    Coherent Cherenkov radiation (CCR) wakefields are produced when a compressed electron beam travels along the axis of a hollow cylindrical dielectric tube. In a dielectric wakefield accelerator (DWA) these wakefields accelerate either a trailing electron bunch or the tail of the driving bunch, depending on the modal structure of the radiation. For an appropriate choice of dielectric structure geometry and beam parameters the device operates in a single-mode regime, producing sinusoidal wakefields with wavelengths in the THz range. We report on preliminary results of an experiment at UCLA studying the potential of a DWA structure to produce high-power, narrow-band THz radiation. First measurements include observation of 1 MW peak-power pulses of coherent broadband radiation from a compact dipole beam dump magnet.

  5. Cherenkov sound on a surface of a topological insulator

    NASA Astrophysics Data System (ADS)

    Smirnov, Sergey

    2013-11-01

    Topological insulators are currently of considerable interest due to peculiar electronic properties originating from helical states on their surfaces. Here we demonstrate that the sound excited by helical particles on surfaces of topological insulators has several exotic properties fundamentally different from sound propagating in nonhelical or even isotropic helical systems. Specifically, the sound may have strictly forward propagation absent for isotropic helical states. Its dependence on the anisotropy of the realistic surface states is of distinguished behavior which may be used as an alternative experimental tool to measure the anisotropy strength. Fascinating from the fundamental point of view backward, or anomalous, Cherenkov sound is excited above the critical angle π/2 when the anisotropy exceeds a critical value. Strikingly, at strong anisotropy the sound localizes into a few forward and backward beams propagating along specific directions.

  6. Vacuum Cherenkov radiation and bremsstrahlung from disformal couplings

    NASA Astrophysics Data System (ADS)

    van de Bruck, Carsten; Burrage, Clare; Morrice, Jack

    2016-08-01

    The simplest way to modify gravity is to extend the gravitational sector to include an additional scalar degree of freedom. The most general metric that can be built in such a theory includes disformal terms, so that standard model fields move on a metric which is the sum of the space time metric and a tensor constructed from first derivatives of the scalar. In such a theory gravitational waves and photons can propagate at different speeds, and these can in turn be different from the maximum speed limit for matter particles. In this work we show that disformal couplings can cause charged particles to emit Cherenkov radiation and bremsstrahlung apparently in vacuum, depending on the background evolution of the scalar field. We discuss the implications of this for observations of cosmic rays, and the constraints that arise for models of dark energy with disformal couplings.

  7. Operation of an X -band dielectric Cherenkov maser amplifier

    SciTech Connect

    Garate, E.; Kosai, H.; Evans, K.; Fisher, A. ); Cherry, R.; Main, W. )

    1990-03-19

    A dielectric Cherenkov maser has operated as an amplifier at a frequency of 9.8 GHz. The amplifier consisted of an electron beam interacting with the TM{sub 01} mode of a cylindrical, dielectric lined waveguide with the rf input provided by a tunable (9--10 GHz), 10 kW magnetron. The dielectric constant of the liner was 10 with inner and outer radii of 1.0 and 1.27 cm, respectively. At electron beam voltage and current of 190 kV and 90 A, respectively, the measured power gain of the amplifier was 11 dB over a 21 cm interaction length with a pulse length of approximately 1 {mu}s.

  8. High-power dielectric Cherenkov maser oscillator experiments

    SciTech Connect

    Main, W. . Lab. for Plasma Research); Cherry, R. ); Garate, E. )

    1990-06-01

    This paper presents the results of a series of experiments conducted on the dielectric Cherenkov maser (DCM) oscillator. The device consists of a cylindrical metallic waveguide of inner radius 3.64 cm which is partially filled with a dielectric liner. Traveling through the lined waveguide is an annular relativistic electron beam. Liners of dielectric constant {epsilon} = 10, 5 and 2.3 were investigated for liner thicknesses of 4 and 6 mm. The 6-mm-thick, {epsilon} = 10 liner generated an RF output of 200 MW for 20 ns at 3.8 Hz with electron-beam parameters of 700 kV, 12 kA, and pulse duration of 100 ns. The maximum measured power output for the other configurations was 80 MW at a frequency of 7 GHz ({epsilon} = 5), with several MW of power output from the polyethylene liner ({epsilon} = 2.3) at a frequency of {approximately} 9 GHz.

  9. Coherent Cherenkov radiation as an intense THz source

    NASA Astrophysics Data System (ADS)

    Bleko, V.; Karataev, P.; Konkov, A.; Kruchinin, K.; Naumenko, G.; Potylitsyn, A.; Vaughan, T.

    2016-07-01

    Diffraction and Cherenkov radiation of relativistic electrons from a dielectric target has been proposed as mechanism for production of intense terahertz (THz) radiation. The use of an extremely short high-energy electron beam of a 4th generation light source (X-ray free electron laser) appears to be very promising. A moderate power from the electron beam can be extracted and converted into THz radiation with nearly zero absorption losses. The initial experiment on THz observation will be performed at CLARA/VELA FEL test facility in the UK to demonstrate the principle to a wider community and to develop the radiator prototype. In this paper, we present our theoretical predictions (based on the approach of polarization currents), which provides the basis for interpreting the future experimental measurements. We will also present our hardware design and discuss a plan of the future experiment.

  10. The large-area hybrid-optics CLAS12 RICH detector: Tests of innovative components

    SciTech Connect

    Contalbrigo, M; Baltzell, N; Benmokhtar, F; Barion, L; Cisbani, E; El Alaoui, A; Hafidi, K; Hoek, M; Kubarovsky, V; Lagamba, L; Lucherini, V; Malaguti, R; Mirazita, M; Montgomery, R; Movsisyan, A; Musico, P; Orecchini, D; Orlandi, A; Pappalardo, L L; Pereira, S; Perrino, R; Phillips, J; Pisano, S; Rossi, P; Squerzanti, S; Tomassini, S; Turisini, M; Viticchiè, A

    2014-07-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadronization and hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and densely packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). The preliminary results of individual detector component tests and of the prototype performance at test-beams are reported here.

  11. Ionization and pulse lethargy effects in inverse Cherenkov accelerators

    SciTech Connect

    Sprangle, P.; Hubbard, R.F.,; Hafizi, B.,

    1997-05-01

    Ionization processes limit the accelerating gradient and place an upper limit on the pulse duration of the electromagnetic driver in the inverse Cherenkov accelerator (ICA). Group velocity slippage, i.e., pulse lethargy, on the other hand, imposes a lower limit on the pulse duration. These limits are obtained for two ICA configurations in which the electromagnetic driver (e.g., laser or millimeter wave source) is propagated in a waveguide that is (i) lined with a dielectric material or (ii) filled with a neutral gas. In either configuration the electromagnetic driving field is guided and has an axial electric field with phase velocity equal to the speed of light in vacuum, c. The intensity of the driver in the ICA, and therefore the acceleration gradient, is limited by tunneling and collisional ionization effects. Partial ionization of the dielectric liner or gas can lead to significant modification of the dispersive properties of the waveguide, altering the phase velocity of the accelerating field and causing particle slippage, thus disrupting the acceleration process. An additional limitation on the pulse duration is imposed since the group velocity of the driving pulse is less than c and the pulse slips behind the accelerated electrons. Hence for sufficiently short pulses the electrons outrun the pulse, terminating the acceleration. Limitations on the driver pulse duration and accelerating gradient, due to ionization and pulse lethargy, are estimated for the two ICA configurations. Maximum accelerating gradients and pulse durations are presented for a 10 {mu}m, 1 mm, and 1 cm wavelength electromagnetic driver. The combination of ionization and pulse lethargy effects impose severe limitations on the maximum energy gain in inverse Cherenkov accelerators. {copyright} {ital 1997} {ital The American Physical Society}

  12. Low-Noise Operation of All-Fiber Femtosecond Cherenkov Laser

    PubMed Central

    Liu, Xiaomin; Villanueva, Guillermo E.; Lægsgaard, Jesper; Møller, Uffe; Tu, Haohua; Boppart, Stephen A.; Turchinovich, Dmitry

    2013-01-01

    We investigate the noise properties of a femtosecond all-fiber Cherenkov radiation source with emission wavelength 600 nm, based on an Yb-fiber laser and a highly nonlinear photonic crystal fiber. A relative intensity noise as low as 103 dBc/Hz, corresponding to 2.48% pulse-to-pulse fluctuation in energy, is observed at the Cherenkov radiation output power of 4.3 mW, or 150 pJ-pulse energy. This pulse-to-pulse fluctuation is at least 10.6-dB lower compared to spectrally sliced supercontinuum sources traditionally used for ultrafast fiber-based generation at visible wavelengths. Low noise makes all-fiber Cherenkov sources promising for biophotonics applications such as multiphoton microscopy, where minimum pulse-to-pulse energy fluctuation is required. We present the dependency of the noise figure on both the Cherenkov radiation output power and its spectrum. PMID:24532961

  13. Research on mutual influence of Cherenkov-type probes within the ISTTOK tokamak chamber

    NASA Astrophysics Data System (ADS)

    Jakubowski, L.; Plyusnin, V. V.; Malinowski, K.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Fernandes, H.; Silva, C.; Figueiredo, H.; Jakubowski, M. J.

    2014-12-01

    The paper describes an influence of a Cherenkov-type probe, which is used for measurements of fast electron streams inside the ISTTOK chamber, on other probes and behaviour of a plasma ring. The reported study shows that such a probe situated near the plasma column has a strong influence on signals from another Cherenkov probe, and can cause a considerable reduction of electron-induced signals. This effect does not depend on positions of the probes in relation to the limiter. Measurements of hard X-ray (HXR) emission show that the deeply immersed Cherenkov probe can also influence on the limiter . Under specific experimental conditions such a Cherenkov probe can play the role of a new limiter and change the plasma configuration.

  14. Transmutation detectors

    NASA Astrophysics Data System (ADS)

    Viererbl, L.; Lahodová, Z.; Klupák, V.; Sus, F.; Kučera, J.; Kůs, P.; Marek, M.

    2011-03-01

    We have designed a new type of detectors, called transmutation detectors, which can be used primarily for neutron fluence measurement. The transmutation detector method differs from the commonly used activation detector method in evaluation of detector response after irradiation. Instead of radionuclide activity measurement using radiometric methods, the concentration of stable non-gaseous nuclides generated by transmutation in the detector is measured using analytical methods like mass spectrometry. Prospective elements and nuclear reactions for transmutation detectors are listed and initial experimental results are given. The transmutation detector method could be used primarily for long-term measurement of neutron fluence in fission nuclear reactors, but in principle it could be used for any type of radiation that can cause transmutation of nuclides in detectors. This method could also be used for measurement in accelerators or fusion reactors.

  15. Study of extensive air showers and primary energy spectra by MAKET-ANI detector on mountain Aragats

    NASA Astrophysics Data System (ADS)

    Chilingarian, A.; Gharagyozyan, G.; Ghazaryan, S.; Hovsepyan, G.; Mamidjanyan, E.; Melkumyan, L.; Romakhin, V.; Vardanyan, A.; Sokhoyan, S.

    2007-09-01

    Small and middle size surface detectors measuring extensive air showers (EAS) initiated by primary cosmic rays (PCR) incident on terrestrial atmosphere have been in operation for the last 50 years. Their main goal is to explore the "knee" in all particle spectrum to solve the problem of cosmic ray (CR) origin and acceleration. The recent achievements of atmospheric Cherenkov telescopes and X-ray space laboratories, establishing the supernova remnants (SNRs) as a source of hadronic cosmic rays, pose stringent conditions on the quality of EAS evidence. After establishing the existence of the "knee" itself, the most pronounced result from EAS studies is the rigidity dependent shift of the knee position to the highest energies. This feature was first observed by separation of the primary flux in different mass groups in MAKET-ANI, EAS-TOP and KASCADE experiments. The MAKET-ANI detector is placed on Mt. Aragats (Armenia) at 3200 m above the sea level (40°25'N, 44°15'E). More than 1.3 × 10 6 showers with size greater than 10 5 particles were registered in 1997-2004. The detector effectively collected the cores of EAS, initiated by primaries with energies of 10 14-10 17 eV. After proving that the quality of the EAS size and shape reconstruction was reasonably high, we present the lateral distribution function (LDF) for distances from 10 to 120 m from EAS core and EAS size spectra in 5 zenith angle intervals. We use CORSIKA simulations to present the energy spectra. The results from the MAKET-ANI experiment on the energy spectra of the "light"(p + He) and "heavy" (O + Si + Fe) nuclear groups are compared to the spectra obtained by balloon experiments and to other available spectra.

  16. The next generation of crystal detectors

    NASA Astrophysics Data System (ADS)

    Zhu, Ren-Yuan

    2015-09-01

    Crystal detectors have been used widely in high energy and nuclear physics experiments, medical instruments and homeland security applications. Novel crystal detectors are continuously being discovered and developed in academia and in industry. In high energy and nuclear physics experiments, total absorption electromagnetic calorimeters (ECAL) made of inorganic crystals are known for their superb energy resolution and detection efficiency for photon and electron measurements. A crystal ECAL is thus the choice for those experiments where precision measurements of photons and electrons are crucial for their physics missions. For future HEP experiments at the energy and intensity frontiers, however, the crystal detectors used in the above mentioned ECALs are either not bright and fast enough, or not radiation hard enough. Crystal detectors have also been proposed to build a Homogeneous Hadron Calorimeter (HHCAL) to achieve unprecedented jet mass resolution by duel readout of both Cherenkov and scintillation light, where development of cost-effective crystal detectors is a crucial issue because of the huge crystal volume required. This paper discusses several R&D directions for the next generation of crystal detectors for future HEP experiments.

  17. Neutron Detection with Water Cerenkov Based Detectors

    SciTech Connect

    Dazeley, S; Bernstein, A; Bowden, N; Carr, D; Ouedraogo, S; Svoboda, R; Sweany, M; Tripathi, M

    2009-05-13

    Legitimate cross border trade involves the transport of an enormous number of cargo containers. Especially following the September 11 attacks, it has become an international priority to verify that these containers are not transporting Special Nuclear Material (SNM) without impeding legitimate trade. Fission events from SNM produce a number of neutrons and MeV-scale gammas correlated in time. The observation of consistent time correlations between neutrons and gammas emitted from a cargo container could, therefore, constitute a robust signature for SNM, since this time coincident signature stands out strongly against the higher rate of uncorrelated gamma-ray backgrounds from the local environment. We are developing a cost effective way to build very large neutron detectors for this purpose. We have recently completed the construction of two new water Cherenkov detectors, a 250 liter prototype and a new 4 ton detector. We present both the results from our prototype detector and an update on the newly commissioned large detector. We will also present pictures from the construction and outline our future detector development plans.

  18. HAWC: The High-Altitude Water Cherenkov observatory for TeV gamma-rays & cosmic-ray anisotropy

    NASA Astrophysics Data System (ADS)

    DuVernois, Michael

    Currently, the High-Altitude Water Cherenkov (HAWC) Observatory is being built at a site about a two hours drive east of Puebla, Mexico, on the Sierra Negra plateau (4100 m a.s.l.). HAWC is unique among TeV gamma-ray instruments since it can observe large portions of the sky in a 24 hour time period and therefore the detector is particularly well suited to measure extended and large-scale structures in the sky like galactic diffuse gamma-ray emission, and both large and small-scale anisotropies. In addition, discoveries of other extended unidentified objects at TeV energies, for example collocated with the “Fermi Bubbles”, and the observation of transient phenomena such as GRBs are possible. The construction of HAWC funded through NSF, DoE, and CONACyT is expected to be complete by Fall 2014. Data are already being collected during construction with an increasingly sensitive detector allowing for synchronous observations with instruments at other wavebands such as the Fermi Space Telescopes. Analysis of the already recorded data reveal significant anisotropies in the arrival directions of cosmic rays at small and large scales. A number of gamma-ray hot spots are also observed along the Galactic plane and the data are searched for high-energy emission from GRBs detected at lower energies. I will present first results and some of the scientific potential of the observatory.

  19. The detector system of the MICE experiment

    NASA Astrophysics Data System (ADS)

    Orestano, D.

    2010-05-01

    Muon ionization cooling provides the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. The muon ionization cooling experiment (MICE) is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance is first measured in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in liquid hydrogen and RF acceleration. A second spectrometer identical to the first one provides a measurement of the outgoing emittance. A particle identification system ensures that the measured muon has not decayed. This paper describes scope and performance of the MICE detector system.

  20. Investigating the Cherenkov light lateral distribution function for primary proton and iron nuclei in extensive air showers

    NASA Astrophysics Data System (ADS)

    Al-Rubaiee, A. A.; Hashim, U.; Al-Douri, Y.

    2015-11-01

    The lateral distribution function (LDF) of Cherenkov radiation in extensive air showers (EAS) was simulated by CORSIKA program for the conditions of Yakutsk Cherenkov array at the high energy range (1013-1016) eV for two primary particles (p and Fe) for different zenith angles. By depending on Breit-Wigner function for analyzing of Cherenkov light LDF, a parameterization of Cherenkov light LDF was reconstructed by depending on CORSIKA simulation as a function of primary energy. The comparison between the estimated Cherenkov light LDF with the LDF that measured on the Yakutsk EAS array gives the ability of particle identification that initiated the shower and determination of particle's energy around the knee region. The extrapolation of approximated Cherenkov light LDF for energies 20 and 30 PeV was obtained for primary particles (p and Fe).

  1. Monitoring of absolute mirror alignment at COMPASS RICH-1 detector

    NASA Astrophysics Data System (ADS)

    Alexeev, M.; Birsa, R.; Bradamante, F.; Bressan, A.; Chiosso, M.; Ciliberti, P.; Dalla Torre, S.; Denisov, O.; Duic, V.; Ferrero, A.; Finger, M.; Finger, M.; Gayde, J. Ch.; Giorgi, M.; Gobbo, B.; Levorato, S.; Maggiora, A.; Martin, A.; Menon, G.; Panzieri, D.; Pesaro, G.; Polak, J.; Rocco, E.; Sbrizzai, G.; Schiavon, P.; Slunecka, M.; Sozzi, F.; Steiger, L.; Sulc, M.; Takekawa, S.; Tessarotto, F.

    2014-12-01

    The gaseous COMPASS RICH-1 detector uses two spherical mirror surfaces, segmented into 116 individual mirrors, to focus the Cherenkov photons onto the detector plane. Any mirror misalignment directly affects the detector resolution. The on-line Continuous Line Alignment and Monitoring (CLAM) photogrammetry-based method has been implemented to measure the alignment of individual mirrors which can be characterized by the center of curvature. The mirror wall reflects a regular grid of retroreflective strips placed inside the detector vessel. Then, the position of each mirror is determined from the image of the grid reflection. The images are collected by four cameras. Any small mirror misalignment results in changes of the grid lines' positions in the image. The accuracy limits of the CLAM method were checked by laser interferometry and are below 0.1 mrad.

  2. New electronics for the Cherenkov Telescope Array (NECTAr)

    NASA Astrophysics Data System (ADS)

    Naumann, C. L.; Delagnes, E.; Bolmont, J.; Corona, P.; Dzahini, D.; Feinstein, F.; Gascón, D.; Glicenstein, J.-F.; Guilloux, F.; Nayman, P.; Rarbi, F.; Sanuy, A.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

    2012-12-01

    The international CTA consortium has recently entered into its preparatory phase towards the construction of the next-generation Cherenkov Telescope Array CTA. This experiment will be a successor, and based on the return of experience from the three major current-generation arrays H.E.S.S., MAGIC and VERITAS, and aims to significantly improve upon the sensitivity as well as the energy range of its highly successful predecessors. Construction is planned to begin by 2013, and when finished, CTA will be able to explore the highest-energy gamma ray sky in unprecedented detail. To achieve this increase in sensitivity and energy range, CTA will employ the order of 100 telescopes of three different sizes on two sites, with around 1000-4000 channels per camera, depending on the telescope size. To equip and reliably operate the order of 100000 channels of photodetectors (compared to 6000 of the H.E.S.S. array), a new kind of flexible and powerful yet inexpensive front-end hardware will be required. One possible solution is pursued by the NECTAr (New Electronics for the Cherenkov Telescope Array) project. Its main feature is the integration of as much as possible of the front-end electronics (amplifiers, fast analogue samplers, memory and ADCs) into a single ASIC, which will allow very fast readout performances while significantly reducing the cost and the power consumption per channel. Also included is a low-cost FPGA for digital treatment and online data processing, as well as an Ethernet connection. Other priorities of NECTAr are the modularity of the system, a high degree of flexibility in the trigger system as well as the possibility of flexible readout modes to optimise the signal-to-noise ratio while at the same time allowing a significant reduction of data rates, both of which could improve the sensitivity of CTA compared to current detection systems. This paper gives an overview over the development work for the Nectar system, with particular focus on its main

  3. The Alignment System for a Medium-Sized Schwarzschild-Couder Telescope Prototype for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Ribeiro, Deivid; Humensky, Brian; Nieto, Daniel; V Vassiliev Group in UCLA division of Astronomy and Astrophysics, P Kaaret Group at Iowa University Department of Physics and Astronomy, CTA Consortium

    2016-01-01

    The Cherenkov Telescope Array (CTA) is an international project for a next-generation ground-based gamma-ray observatory. CTA, conceived as an array of tens of imaging atmospheric Cherenkov telescopes, comprising small, medium and large-size telescopes, is aiming to improve on the sensitivity of current-generation experiments by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV. The Schwarzschild-Couder design is a candidate 9-m diameter medium-sized telescope featuring a novel aplanatic two-mirror optical design capable of a wide field of view with significantly improved imaging resolution as compared to the traditional Davies-Cotton optical design. Achieving this imaging resolution imposes strict mirror alignment requirements that necessitate a sophisticated alignment system. This system uses a collection of position sensors between panels to determine the relative position of adjacent panels; each panel is mounted on a Stewart platform to allow motion control with six degrees of freedom, facilitating the alignment of the optical surface for the segmented primary and secondary mirrors. Alignments of the primary and secondary mirrors and the camera focal plane with respect to each other are performed utilizing a set of CCD cameras which image LEDs placed on the mirror panels to measure relative translation, and custom-built auto-collimators to measure relative tilt between the primary and secondary mirrors along the optical axis of the telescope. In this contribution we present the status of the development of the SC optical alignment system, soon to be materialized in a full-scale prototype SC medium-size telescope (pSCT) at the Fred Lawrence Whipple Observatory in southern Arizona.

  4. Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS)

    SciTech Connect

    Otte, A. N.; Williams, D. A.; Byrum, K.; Drake, G.; Horan, D.; Smith, A.; Wagner, R. G.; Falcone, A.; Funk, S.; Tajima, H.; Mukherjee, R.

    2008-12-24

    The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. Design goals are ten times better sensitivity, higher angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel diameter is reduced to the order of 0.05 deg, i.e. two to three times smaller than the pixel diameter of current Cherenkov telescope cameras. At these dimensions, photon detectors with smaller physical dimensions can be attractive alternatives to the classical photomultiplier tube (PMT). Furthermore, the operation of an experiment with the size of AGIS requires photon detectors that are among other things more reliable, more durable, and possibly higher efficiency photon detectors. Alternative photon detectors we are considering for AGIS include both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs). Here we present results from laboratory testing of MAPMTs and SiPMs along with results from the first incorporation of these devices into cameras on test bed Cherenkov telescopes.

  5. The ASTRI mini-array within the future Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Vercellone, Stefano

    2016-07-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to very high-energy gamma-ray astrophysics in the energy range from a few tens of GeV to above 100 TeV, which will yield about an order of magnitude improvement in sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). Within this framework, the Italian National Institute for Astrophysics is leading the ASTRI project, whose main goals are the design and installation on Mt. Etna (Sicily) of an end-to-end dual-mirror prototype of the CTA small size telescope (SST) and the installation at the CTA Southern site of a dual-mirror SST mini-array composed of nine units with a relative distance of about 300 m. The innovative dual-mirror Schwarzschild-Couder optical solution adopted for the ASTRI Project allows us to substantially reduce the telescope plate-scale and, therefore, to adopt silicon photo-multipliers as light detectors. The ASTRI mini-array is a wider international effort. The mini-array, sensitive in the energy range 1-100 TeV and beyond with an angular resolution of a few arcmin and an energy resolution of about 10-15%, is well suited to study relatively bright sources (a few × 10-12 erg cm-2 s-1 at 10 TeV) at very high energy. Prominent sources such as extreme blazars, nearby well-known BL Lac objects, Galactic pulsar wind nebulae, supernovae remnants, micro-quasars, and the Galactic Center can be observed in a previously unexplored energy range. The ASTRI mini-array will extend the current IACTs sensitivity well above a few tens of TeV and, at the same time, will allow us to compare our results on a few selected targets with those of current (HAWC) and future high-altitude extensive air-shower detectors.

  6. SU-E-I-87: Calibrating Cherenkov Emission to Match Superficial Dose in Tissue

    SciTech Connect

    Zhang, R; Pogue, B; Glaser, A; Gladstone, D

    2015-06-15

    Purpose: Through Monte Carlo simulations and phantom studies, the dominant factors affecting the calibration of superficial Cherenkov intensity to absolute surface dose was investigated, including tissue optical properties, curvatures, beam properties and imaging angle. Methods: The phasespace files for the TrueBeam system from Varian were used in GAMOS (a GEANT4 based Monte Carlo simulation toolkit) to simulate surface emission Cherenkov signals and the correlated deposited dose. The parameters examined were: i) different tissue optical properties (skin color from light to dark), ii) beam types (X-ray and electron beam), iii) beam energies, iv) thickness of tissues (2.5 cm to 20 cm), v) SSD (80 cm to 120 cm), vi) field sizes (0.5×0.5 cm2 to 20×20 cm2), vii) entrance/exit sides, viii) curvatures (cylinders with diameters from 2.5 cm to 20cm) and ix) imaging angles (0 to 90 degrees). In a specific case, for any Cherenkov photon emitted from the surface, the original position and direction, final position and direction and energy were recorded. Similar experimental measurements were taken in a range of the most pertinent parameters using tissue phantoms. Results: Combining the dose distribution and sampling sensitivity of Cherenkov emission, quantitatively accurate calibration factors (the amount of radiation dose represented by a single Cherenkov photon) were calculated. The data showed relatively large dependence upon different optical properties, curvature, entrance/exit and beam types. For a diffusive surface, the calibration factor was insensitive to imaging angles smaller than 60 degrees. Normalization with the reflectance image was experimentally validated as a simple and accurate method for calibrations of different optical properties. Conclusion: This study sheds light on how and to what extent different conditions affect the calibration from Cherenkov intensity to absolute superficial dose and provides practical solutions to allow quantitative Cherenkov

  7. Charged Kaon Mass Measurement using the Cherenkov Effect

    SciTech Connect

    Graf, N.; Lebedev, A.; Abrams, R.J.; Akgun, U.; Aydin, G.; Baker, W.; Barnes, P.D., Jr.; Bergfeld, T.; Beverly, L.; Bujak, A.; Carey, D.; /Fermilab /Virginia U. /Iowa U.

    2009-09-01

    The two most recent and precise measurements of the charged kaon mass use X-rays from kaonic atoms and report uncertainties of 14 ppm and 22 ppm yet differ from each other by 122 ppm. We describe the possibility of an independent mass measurement using the measurement of Cherenkov light from a narrow-band beam of kaons, pions, and protons. This technique was demonstrated using data taken opportunistically by the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory which recorded beams of protons, kaons, and pions ranging in momentum from +37 GeV/c to +63 GeV/c. The measured value is 491.3 {+-} 1.7 MeV/c{sup 2}, which is within 1.4{sigma} of the world average. An improvement of two orders of magnitude in precision would make this technique useful for resolving the ambiguity in the X-ray data and may be achievable in a dedicated experiment.

  8. Time-Domain Measurement of Broadband Coherent Cherenkov Radiation

    SciTech Connect

    Miocinovic, P.; Field, R.C.; Gorham, P.W.; Guillian, E.; Milincic, R.; Saltzberg, D.; Walz, D.; Williams, D.; /UCLA

    2006-03-13

    We report on further analysis of coherent microwave Cherenkov impulses emitted via the Askaryan mechanism from high-energy electromagnetic showers produced at the Stanford Linear Accelerator Center (SLAC). In this report, the time-domain based analysis of the measurements made with a broadband (nominally 1-18 GHz) log periodic dipole antenna (LPDA) is described. The theory of a transmit-receive antenna system based on time-dependent effective height operator is summarized and applied to fully characterize the measurement antenna system and to reconstruct the electric field induced via the Askaryan process. The observed radiation intensity and phase as functions of frequency were found to agree with expectations from 0.75-11.5 GHz within experimental errors on the normalized electric field magnitude and the relative phase; {sigma}{sub R|E|} = 0.039 {micro}V/MHz/TeV and {sigma}{sub {phi}} = 17{sup o}. This is the first time this agreement has been observed over such a broad bandwidth, and the first measurement of the relative phase variation of an Askaryan pulse. The importance of validation of the Askaryan mechanism is significant since it is viewed as the most promising way to detect cosmogenic neutrino fluxes at E{sub v} {ge} 10{sup 15} eV.

  9. Time-domain measurement of broadband coherent Cherenkov radiation

    SciTech Connect

    Miocinovic, P.; Gorham, P. W.; Guillian, E.; Milincic, R.; Field, R. C.; Walz, D.; Saltzberg, D.; Williams, D.

    2006-08-15

    We report on further analysis of coherent microwave Cherenkov impulses emitted via the Askaryan mechanism from high-energy electromagnetic showers produced at the Stanford Linear Accelerator Center (SLAC). In this report, the time-domain based analysis of the measurements made with a broadband (nominally 1-18 GHz) log periodic dipole array antenna is described. The theory of a transmit-receive antenna system based on time-dependent effective height operator is summarized and applied to fully characterize the measurement antenna system and to reconstruct the electric field induced via the Askaryan process. The observed radiation intensity and phase as functions of frequency were found to agree with expectations from 0.75-11.5 GHz within experimental errors on the normalized electric field magnitude and the relative phase; {sigma}{sub RvertcalbarEverticalbar}=0.039 {mu}V/MHz/TeV and {sigma}{sub {phi}}=17 deg. This is the first time this agreement has been observed over such a broad bandwidth, and the first measurement of the relative phase variation of an Askaryan pulse. The importance of validation of the Askaryan mechanism is significant since it is viewed as the most promising way to detect cosmogenic neutrino fluxes at E{sub {nu}}(greater-or-similar sign)10{sup 15} eV.

  10. Gravitational Cherenkov losses in theories based on modified Newtonian dynamics.

    PubMed

    Milgrom, Mordehai

    2011-03-18

    Survival of high-energy cosmic rays (HECRs) against gravitational Cherenkov losses is shown not to cast strong constraints on modified Newtonian dynamics (MOND) theories that are compatible with general relativity (GR): theories that coincide with GR for accelerations ≫a(0) (a(0) is the MOND constant). The energy-loss rate, E, is many orders smaller than those derived in the literature for theories with no extra scale. Modification to GR, which underlies E, enters only beyond the MOND radius of the particle: r(M)=(Gp/ca(0))(1/2). The spectral cutoff, entering E quadratically, is thus r(M)(-1), not k(dB)=p/ℏ. Thus, E is smaller than published rates, which use k(dB), by a factor ∼(r(M)k(dB))(2)≈10(39)(cp/3×10(11)  Gev)(3). Losses are important only beyond D(loss)≈qℓ(M), where q is a dimensionless factor, and ℓ(M)=c(2)/a(0) is the MOND length, which is ≈2π times the Hubble distance. PMID:21469855

  11. Evaluation of polarized terahertz waves generated by Cherenkov phase matching.

    PubMed

    Akiba, Takuya; Akimoto, Yasuhiro; Suizu, Koji; Miyamoto, Katsuhiko; Omatsu, Takashige

    2014-03-10

    We report terahertz (THz) wave generation by satisfying Cherenkov phase-matching condition in both s and p polarizations. A dual-wavelength optical parametric oscillator is constructed from two potassium titanium oxide phosphate crystals pumped by a frequency-doubled Nd:YAG laser. By rotating the orientation of both a lithium niobate crystal (LiNbO3) and the polarization of the pump waves, the polarization of the THz wave changes. Due to the difference in the refractive index and absorption, the output power for p polarization is one tenth that for s polarization. A tuning range from 0.2 to 6.5 THz is obtained for s polarization, and from 0.2 to 4.2 and 5.4 to 6.9 THz for p polarization. The extraction efficiency is improved by changing the angle of prism for p polarization, and a large phase change occurs at total internal reflection. Consequently, p-polarized THz waves are optimal for spectroscopic applications.

  12. Cherenkov radiation with massive, C P T -violating photons

    NASA Astrophysics Data System (ADS)

    Colladay, Don; McDonald, Patrick; Potting, Robertus

    2016-06-01

    The source of C P T violation in the photon sector of the Standard Model Extension arises from a Chern-Simons-like contribution that involves a coupling to a fixed background vector field kAF μ . These Lorentz- and C P T -violating photons have well-known theoretical issues that arise from missing states at low momenta when kAF μ is timelike. In order to make the theory consistent, a tiny mass for the photon can be introduced, well below current experimental bounds. The implementation of canonical quantization can then be implemented as in the C P T -preserving case by using the Stückelberg mechanism. We explicitly construct a covariant basis of properly normalized polarization vectors at fixed three-momentum satisfying the momentum space field equations, in terms of which the vector field can be expanded. As an application of the theory, we calculate the Cherenkov radiation rate for the case of purely timelike kAF μ and find a radiation rate at high energies that has a contribution that does not depend on the mass used to regulate the photons.

  13. Studies of the Energy Spectra of Incident Cosmic Radiation by the Networks of Particle Detectors

    NASA Astrophysics Data System (ADS)

    Chilingarian, Ashot A.; Hovsyapayan, Gagik G.

    2007-08-01

    There are numerous indications that particle acceleration took place in supernovae remnants, by pulsars, super-massive black holes, in the galaxy clusters and by stars. As a universal mechanism operated on different scales the stochastic and shock acceleration is pointed. It is very important to use our nearest star - the sun, as laboratory in studying particle acceleration phenomena. The surface particle detectors, along with space-born spectrometers are capable of detecting solar particles in the energy range from KeVs till several Tens of GeV. The large surface arrays are detecting particle in energy range from ~100 TeV till EeV. This richness of information on particle fluxes on different scales can be used in studying physical processes responsible for particle acceleration in Universe. Surface detectors measuring Extensive Air Showers (EAS) initiated by Primary Cosmic Rays (PCR) incident on terrestrial atmosphere have been in operation since the last 50 years with main goal to explore the major enigma of Cosmic Ray (CR) origin and acceleration. Recent achievements of the Atmospheric Cherenkov Telescopes and X-ray space laboratories, establishing the supernova remnants (SNRs) as source of hadronic cosmic rays pose stringent conditions on the quality of the EAS evidence. After establishing the existence of the “knee” in all particle spectrum the most pronounced result from EAS studies is the rigidity dependent shift of the knee position to the highest energies. This feature first observed by the exploiting the separation of the primary beam in different groups of mass in MAKET-ANI, EAS-TOP and KASCADE experiments also pointed to the SNR blast shocks as CR source. The MAKET ANI detector is placed on mountain Aragats (Armenia) on 3200m at sea level (40.50N, 44.20E). More than 1.3 x 10^6 showers with size greater than 10^5 were registered in 1997-2004. The detector has effectively collected the cores of EAS, initiated by primaries with energies of 5 × 10

  14. Results from first beam tests for the development of a RICH detector for CBM

    NASA Astrophysics Data System (ADS)

    Eschke, J.; Höhne, C.

    2011-05-01

    In the CBM experiment at FAIR, electrons will be identified using a gaseous RICH detector positioned behind a system of silicon tracking stations. The concept of the RICH detector foresees an array of Multianode Photomultipliers (MAPMTs) as photodetector. First beam test data with a 2 GeV proton beam were recorded to investigate the Cherenkov light detection with a 64 channel Hamamatsu H8500 MAPMT. In the beam test a proximity focusing setup with a solid radiator was used together with a new self triggered readout electronics based on the n-XYTER ADC chip. The results of this beam test demonstrate that the new front end electronics is suited for the readout of the Hamamatsu H8500 MAPMT. It could be demonstrated that this MAPMT is able to detect single Cherenkov photons. Uncorrelated noise could be well separated from the signal using available timing information. The recorded number of MAPMT hits per beam event is consistent with the expectations.

  15. Smoke Detector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    In the photo, Fire Chief Jay Stout of Safety Harbor, Florida, is explaining to young Richard Davis the workings of the Honeywell smoke and fire detector which probably saved Richard's life and that of his teen-age brother. Alerted by the detector's warning, the pair were able to escape their burning home. The detector in the Davis home was one of 1,500 installed in Safety Harbor residences in a cooperative program conducted by the city and Honeywell Inc.

  16. SYNCHROTRON EMISSION DRIVEN BY THE CHERENKOV-DRIFT INSTABILITY IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Osmanov, Z.; Chkheidze, N.

    2013-02-10

    In the present paper, we study the generation of synchrotron emission by means of the feedback of Cherenkov-drift waves on the particle distribution through the diffusion process. Despite the efficient synchrotron losses, it is demonstrated that the excited Cherenkov-drift instability leads to the quasi-linear diffusion (QLD), the effect of which is balanced by dissipation factors and, as a result, the pitch angles are prevented from damping, thus maintaining the corresponding synchrotron emission. We analyze the model for a wide range of physical parameters and determine that the mechanism of QLD guarantees the generation of electromagnetic radiation from soft X-rays up to soft {gamma}-rays, which is strongly correlated with Cherenkov-drift emission ranging from IR up to UV energy domains.

  17. Reversed Cherenkov-Transition Radiation by a Charge Crossing a Left-Handed Medium Boundary

    SciTech Connect

    Galyamin, Sergey N.; Tyukhtin, Andrey V.; Kanareykin, Alexey; Schoessow, Paul

    2009-11-06

    We analyze the radiation from a charged particle crossing the boundary between an ordinary medium and a 'left-handed' metamaterial. We obtain exact and approximate expressions for the field components and develop algorithms for their computation. The spatial radiation in this system can be separated into three distinct components, corresponding to ordinary transition radiation having a relatively large magnitude, Cherenkov radiation, and reversed Cherenkov-transition radiation (RCTR). The last one is explained by reflection and refraction of reversed Cherenkov radiation at the interface. Conditions for generating of RCTR are obtained. We note properties of this radiation that have potential applications in the detection of charged particles and accelerator beams and for the characterization of metamaterial macroscopic parameters (epsilon, mu).

  18. Quantum calculation of the Vavilov-Cherenkov radiation by twisted electrons

    NASA Astrophysics Data System (ADS)

    Ivanov, I. P.; Serbo, V. G.; Zaytsev, V. A.

    2016-05-01

    We present a detailed quantum electrodynamical description of Vavilov-Cherenkov radiation emitted by a relativistic twisted electron in the transparent medium. Simple expressions for the spectral and spectral-angular distributions as well as for the polarization properties of the emitted radiation are obtained. Unlike the plane-wave case, the twisted electron produces radiation within the annular angular region, with enhancement towards its boundaries. Additionally, the emitted photons can have linear polarization not only in the scattering plane but also in the orthogonal direction. We find that the Vavilov-Cherenkov radiation emitted by an electron in a superposition of two vortex states exhibits a strong azimuthal asymmetry. Thus, the Vavilov-Cherenkov radiation offers itself as a convenient diagnostic tool of such electrons and complements the traditional microscopic imaging.

  19. Cherenkov light detection as a velocity selector for uranium fission products at intermediate energies

    NASA Astrophysics Data System (ADS)

    Yamaguchi, T.; Enomoto, A.; Kouno, J.; Yamaki, S.; Matsunaga, S.; Suzaki, F.; Suzuki, T.; Abe, Y.; Nagae, D.; Okada, S.; Ozawa, A.; Saito, Y.; Sawahata, K.; Kitagawa, A.; Sato, S.

    2014-12-01

    The in-flight particle separation capability of intermediate-energy radioactive ion (RI) beams produced at a fragment separator can be improved with the Cherenkov light detection technique. The cone angle of Cherenkov light emission varies as a function of beam velocity. This can be exploited as a velocity selector for secondary beams. Using heavy ion beams available at the HIMAC synchrotron facility, the Cherenkov light angular distribution was measured for several thin radiators with high refractive indices (n = 1.9 ~ 2.1). A velocity resolution of ~10-3 was achieved for a 56Fe beam with an energy of 500 MeV/nucleon. Combined with the conventional rigidity selection technique coupled with energy-loss analysis, the present method will enable the efficient selection of an exotic species from huge amounts of various nuclides, such as uranium fission products at the BigRIPS fragment separator located at the RI Beam Factory.

  20. BER performance of MSK in ground-to-satellite uplink optical communication under the influence of atmospheric turbulence and detector noise.

    PubMed

    Ding, Jiachen; Li, Mi; Tang, Minghui; Li, Yan; Song, Yuejiang

    2013-09-15

    Minimum shift keying (MSK) has been widely used in fiber optical communication and free-space optical communication. In order to introduce MSK into satellite laser communication, the bit-error rate (BER) performance of the MSK scheme is investigated in uplink communications under the influence of atmospheric turbulence consisting of weak fluctuation and beam wander. Numerical results indicate that the BER performance of MSK is much better than the performance of on-off keying (OOK). With the laser power being 4 W, the improvement is 5 dB in coherent demodulation and 15 dB in delay coherent demodulation. Furthermore, compared with OOK, optimal values of the divergence angle, receiver diameter, and transmitter beam radius are easier and more practical to achieve in the MSK scheme. The work can benefit ground-to-satellite laser uplink communication system design.

  1. Pulsars at the Highest Energies: Questions for AGILE, Fermi (GLAST) and Atmospheric Cherenkov Telescopes

    NASA Technical Reports Server (NTRS)

    Thompson, D.J.

    2008-01-01

    Observational studies of gamma-ray pulsars languished in recent years, while theoretical studies made significant strides. Now, with new and improved gamma-ray telescopes coming online, opportunities present themselves for dramatic improvements in our understanding of these objects. The new facilities and better modeling of processes at work in high-energy pulsars should address a number of important open questions, some of which are summarized.

  2. Optical Detectors

    NASA Astrophysics Data System (ADS)

    Goushcha, Alexander; Tabbert, Bernd

    Optical detectors are applied in all fields of human activities - from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  3. Optical Detectors

    NASA Astrophysics Data System (ADS)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  4. Radioassay of dual-labeled samples with a Cherenkov counting technique

    NASA Astrophysics Data System (ADS)

    Fujii, Haruo; Takiue, Makoto

    1998-03-01

    A new Cherenkov counting technique which allows radioactivities of a dual-labeled sample to be determined simultaneously by using a wavelength shifter has been proposed, and tested for the pairs 32P-36Cl and 86Rb-36Cl. The minimum requirements for this method are a single channel liquid scintillation counter, a wavelength shifter and a reference sample for determining the Cherenkov counting efficiency. The simple procedure for sample preparation and measurement makes the technique very useful for routine radioassay with the help of a desk-top computer.

  5. Radioassay of dual-labeled samples with a Cherenkov counting technique

    NASA Astrophysics Data System (ADS)

    Fujii, Haruo; Takiue, Makoto

    1988-03-01

    A new Cherenkov counting technique which allows radioactivities of a dual-labeled sample to be determined simultaneously by using a wavelength shifter has been proposed, and tested for the pairs 32P 36Cl and 86Rb 36Cl. The minimum requirements for this method are a single channel liquid scintillation counter, a wavelength shifter and a reference sample for determining the Cherenkov counting efficiency. The simple procedure for sample preparation and measurement makes the technique very useful for routine radioassay with the help of a desk-top computer.

  6. Constraints on general second-order scalar-tensor models from gravitational Cherenkov radiation

    SciTech Connect

    Kimura, Rampei; Yamamoto, Kazuhiro E-mail: kazuhiro@hiroshima-u.ac.jp

    2012-07-01

    We demonstrate that the general second-order scalar-tensor theories, which have attracted attention as possible modified gravity models to explain the late time cosmic acceleration, could be strongly constrained from the argument of the gravitational Cherenkov radiation. To this end, we consider the purely kinetic coupled gravity and the extended galileon model on a cosmological background. In these models, the propagation speed of tensor mode could be less than the speed of light, which puts very strong constraints from the gravitational Cherenkov radiation.

  7. The Angra Project: Monitoring Nuclear Reactors with Antineutrino Detectors

    SciTech Connect

    Anjos, J. C.; Barbosa, A. F.; Lima, H. P. Jr.; Bezerra, T. J. C.; Gonzalez, L. F. G.; Kemp, E.; Chimenti, P.; Leigui de Oliveira, M. A.; Lima, R. M.; Nunokawa, H.

    2010-03-30

    We present the status of the Angra Neutrino project, describing the development of an antineutrino detector aimed at monitoring nuclear reactor activity. The experiment will take place at the Brazilian nuclear power plant located in Angra dos Reis. The Angra II reactor, with 4 GW of thermal power, will be used as a source of antineutrinos. A water Cherenkov detector will be placed above ground in a commercial container outside the reactor containment, about 30 m from the reactor core. With a detector of one ton scale a few thousand antineutrino interactions per day are expected. We intend, in a first step, to use the measured neutrino event rate to monitor the on--off status and the thermal power delivered by the reactor. In addition to the safeguards issues the project will provide an alternative tool to have an independent measurement of the reactor power.

  8. The Surface Detector System of the Pierre Auger Observatory

    SciTech Connect

    Allekotte, I.; Barbosa, A.F.; Bauleo, P.; Bonifazi, C.; Civit, B.; Escobar, C.O.; Garcia, B.; Guedes, G.; Gomez Berisso, M.; Harton, J.L.; Healy, M.; /Cuyo U. /Buenos Aires, CONICET /Natl. Tech. U., San Rafael /Campinas State U. /UEFS, Feira de Santana /Bahia U. /BUAP, Puebla /Santiago de Compostela U. /Fermilab /UCLA /Colorado State U.

    2007-11-01

    The Pierre Auger Observatory is designed to study cosmic rays with energies greater than 10{sup 19} eV. Two sites are envisaged for the observatory, one in each hemisphere, for complete sky coverage. The southern site of the Auger Observatory, now approaching completion in Mendoza, Argentina, features an array of 1600 water-Cherenkov surface detector stations covering 3000 km{sup 2}, together with 24 fluorescence telescopes to record the air shower cascades produced by these particles. The two complementary detector techniques together with the large collecting area form a powerful instrument for these studies. Although construction is not yet complete, the Auger Observatory has been taking data stably since January 2004 and the first physics results are being published. In this paper we describe the design features and technical characteristics of the surface detector stations of the Pierre Auger Observatory.

  9. A RICH detector for hadron identification at Jlab

    SciTech Connect

    Mammoliti, Francesco; Cisbani, Evaristo; Cusanno, Francesco; Garibaldi, Franco; Guisa, Antonio; De Jager, Cornelis; Russo, Guiseppe; Leda Sperduto, Maria; Sutera, Concetta; Urciuoli, Guido

    2011-08-01

    The “standard” Hall A apparatus at Jefferson Lab (TOF and aerogel threshold Cherenkov detectors) does not provide complete identification for proton, kaon and pion. To this aim, a proximity focusing C6F14/CsI RICH (Ring Image Cherenkov) detector has been designed, built, tested and operated to separate kaons from pions with a pion contamination of a few percent up to 2.4 GeV/c. Two quite different experimental investigations have benefitted of the RICH identification: on one side, the high-resolution hypernuclear spectroscopy series of experiments on carbon, beryllium and oxygen, devoted to the study of the lambda-nucleon potential. On the other side, the measurements of the single spin asymmetries of pion and kaon on a transversely polarized 3He target are of utmost interest in understanding QCD dynamics in the nucleon. We present the technical features of such a RICH detector and comment on the presently achieved performance in hadron identification.

  10. Fabrication of the CALDER light detectors

    NASA Astrophysics Data System (ADS)

    Colantoni, I.; Bellini, F.; Cardani, L.; Casali, N.; Castellano, M. G.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; D`Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.; Vignati, M.

    2016-07-01

    CALDER (Cryogenic wide-Area Light Detectors with Excellent Resolution) is a project for the development of large area phonon mediated KIDs (Kinetic Inductance Detectors), for the detection of Cherenkov radiation emitted in TeO2 bolometers to search for neutrinoless double beta decay (0 νββ). The KIDs are superconducting detectors made of high quality factor superconducting resonators, which are coupled to a transmission line for signal readout. We designed and fabricated KIDs using aluminum. The Al thin films (40 nm) were evaporated on Si(100) high resistivity silicon wafers using an electron beam evaporator in a HV chamber. In this work we report the steps of the fabrication process. All devices are made in direct-write using Electron Beam Lithography (EBL), positive tone resist poly-methyl methacrylate (PMMA) and lift off process. In order to improve the sensitivity of the detectors we have started recently to use sub-stoichiometric TiN deposited by means of DC magnetron sputtering and we will optimize a different fabrication process.

  11. The upgraded LHCb RICH detector: Status and perspectives

    NASA Astrophysics Data System (ADS)

    Cardinale, R.

    2016-07-01

    The LHCb upgrade will take place during the second long shutdown of the LHC (LS2). The upgrade will enable the experiment to run at an instantaneous luminosity of 2 ×1033cm-2s-1 and will read out data at a rate of 40 MHz into a flexible software-based trigger. The two Ring Imaging Cherenkov detectors (RICH), installed in the LHCb experiment, will be re-designed to comply with these new operating conditions. The status and perspective of the RICH upgrade project will be presented.

  12. IceCube: A Cubic Kilometer Radiation Detector

    SciTech Connect

    IceCube Collaboration; Klein, Spencer R; Klein, S.R.

    2008-06-01

    IceCube is a 1 km{sup 3} neutrino detector now being built at the Amudsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate {nu}{sub {mu}}, {nu}{sub t}, and {nu}{sub {tau}} interactions because of their different topologies. IceCube construction is currently 50% complete.

  13. Mixed optical Cherenkov-Bremsstrahlung radiation in vicinity of the Cherenkov cone from relativistic heavy ions: Unusual dependence of the angular distribution width on the radiator thickness

    NASA Astrophysics Data System (ADS)

    Rozhkova, E. I.; Pivovarov, Yu. L.

    2016-07-01

    The Cherenkov radiation (ChR) angular distribution is usually described by the Tamm-Frank (TF) theory, which assumes that relativistic charged particle moves uniformly and rectilinearly in the optically transparent radiator. According to the TF theory, the full width at half maximum (FWHM) of the ChR angular distribution inversely depends on the radiator thickness. In the case of relativistic heavy ions (RHI) a slowing-down in the radiator may sufficiently change the angular distribution of optical radiation in vicinity of the Cherenkov cone, since there appears a mixed ChR-Bremsstrahlung radiation. As a result, there occurs a drastic transformation of the FWHM of optical radiation angular distribution in dependence on the radiator thickness: from inversely proportional (TF theory) to the linearly proportional one. In our paper we present the first analysis of this transformation taking account of the gradual velocity decrease of RHI penetrating through a radiator.

  14. Gaseous Detectors

    NASA Astrophysics Data System (ADS)

    Titov, Maxim

    Since long time, the compelling scientific goals of future high-energy physics experiments were a driving factor in the development of advanced detector technologies. A true innovation in detector instrumentation concepts came in 1968, with the development of a fully parallel readout for a large array of sensing elements - the Multi-Wire Proportional Chamber (MWPC), which earned Georges Charpak a Nobel prize in physics in 1992. Since that time radiation detection and imaging with fast gaseous detectors, capable of economically covering large detection volumes with low mass budget, have been playing an important role in many fields of physics. Advances in photolithography and microprocessing techniques in the chip industry during the past decade triggered a major transition in the field of gas detectors from wire structures to Micro-Pattern Gas Detector (MPGD) concepts, revolutionizing cell-size limitations for many gas detector applications. The high radiation resistance and excellent spatial and time resolution make them an invaluable tool to confront future detector challenges at the next generation of colliders. The design of the new micro-pattern devices appears suitable for industrial production. Novel structures where MPGDs are directly coupled to the CMOS pixel readout represent an exciting field allowing timing and charge measurements as well as precise spatial information in 3D. Originally developed for the high-energy physics, MPGD applications have expanded to nuclear physics, photon detection, astroparticle and neutrino physics, neutron detection, and medical imaging.

  15. MS Detectors

    SciTech Connect

    Koppenaal, David W.; Barinaga, Charles J.; Denton, M Bonner B.; Sperline, Roger P.; Hieftje, Gary M.; Schilling, G. D.; Andrade, Francisco J.; Barnes IV., James H.

    2005-11-01

    Good eyesight is often taken for granted, a situation that everyone appreciates once vision begins to fade with age. New eyeglasses or contact lenses are traditional ways to improve vision, but recent new technology, i.e. LASIK laser eye surgery, provides a new and exciting means for marked vision restoration and improvement. In mass spectrometry, detectors are the 'eyes' of the MS instrument. These 'eyes' have also been taken for granted. New detectors and new technologies are likewise needed to correct, improve, and extend ion detection and hence, our 'chemical vision'. The purpose of this report is to review and assess current MS detector technology and to provide a glimpse towards future detector technologies. It is hoped that the report will also serve to motivate interest, prompt ideas, and inspire new visions for ion detection research.

  16. Inverse Cherenkov and inverse FEL accelerator experiments at the Brookhaven Accelerator Test Facility

    SciTech Connect

    Pogorelsky, I.V.; vanSteenbergen, A.; Babzien, M.

    1995-12-31

    Status update on the ongoing inverse Cherenkov acceleration experiment and prospects to its 100 MeV short-term upgrade. The first report on 1 MeV electron acceleration with the 0.5 GW CO{sub 2} laser used in the inverse FEL scheme. (author). 22 refs., 8 figs., 1 tab.

  17. Visual comparisons between Cherenkov radiation from water and fluorescence from a scintillator.

    PubMed

    Tabushi, Katsuyoshi; Tamiya, Tadashi; Maruhashi, Akira; Koyama, Shuji; Homma, Mitsuhiko; Obata, Yasunori; Shimomura, Kouhei; Ikagawa, Hiroyuki

    2003-01-01

    A system for observing blue light of Cherenkov radiation was constructed using a Co-60 gamma-ray irradiation unit. However, there was some doubt that the observed light was not Cherenkov light, but scintillation. Therefore, the radiation from water was compared with that from a scintillator. The difference between both luminosities was examined using photographs taken in a dark irradiation room with mirrors and a camera. The radiation from the scintillator was much stronger than that from water. The differences between luminosities of the light radiated in the beam direction, at right angles to the beam and in the reverse beam direction were examined for both radiations. The luminosity from water showed very definite anisotropy, while that from the scintillator was almost isotropic. Furthermore, the light radiated in the beam direction from water was the strongest, and the strengths of the light radiated in the three directions from the scintillator were almost equivalent to each other. It was confirmed that the radiation from water irradiated by Co-60 gamma-rays was indeed Cherenkov light. The anisotropy of the radiated Cherenkov light and the isotropy of the scintillation were clearly observed in the photographs.

  18. Electron beam diagnostics tool based on Cherenkov radiation in optical fibers

    NASA Astrophysics Data System (ADS)

    Vukolov, A. V.; Novokshonov, A. I.; Potylitsyn, A. P.; Uglov, S. R.

    2016-07-01

    The results of experimental investigations of Cherenkov radiation in optical fibers with 0.6 mm thickness which were used to scan an electron beam of 5.7 MeV energy are presented. Using such a technique for beam profile measurements it is possible to create a compact and reliable device compared to existing systems based on ionization chambers.

  19. Effect of atmospheric turbulence on the bit error probability of a space to ground near infrared laser communications link using binary pulse position modulation and an avalanche photodiode detector

    NASA Technical Reports Server (NTRS)

    Safren, H. G.

    1987-01-01

    The effect of atmospheric turbulence on the bit error rate of a space-to-ground near infrared laser communications link is investigated, for a link using binary pulse position modulation and an avalanche photodiode detector. Formulas are presented for the mean and variance of the bit error rate as a function of signal strength. Because these formulas require numerical integration, they are of limited practical use. Approximate formulas are derived which are easy to compute and sufficiently accurate for system feasibility studies, as shown by numerical comparison with the exact formulas. A very simple formula is derived for the bit error rate as a function of signal strength, which requires only the evaluation of an error function. It is shown by numerical calculations that, for realistic values of the system parameters, the increase in the bit error rate due to turbulence does not exceed about thirty percent for signal strengths of four hundred photons per bit or less. The increase in signal strength required to maintain an error rate of one in 10 million is about one or two tenths of a db.

  20. Design and performance of a lead fluoride detector as a luminosity monitor

    NASA Astrophysics Data System (ADS)

    Pérez Benito, R.; Khaneft, D.; O'Connor, C.; Capozza, L.; Diefenbach, J.; Gläser, B.; Ma, Y.; Maas, F. E.; Rodríguez Piñeiro, D.

    2016-08-01

    Precise luminosity measurements for the OLYMPUS two-photon exchange experiment at DESY were performed by counting scattering events with alternating beams of electrons and positrons incident on atomic electrons in a gaseous hydrogen target. Final products of Møller, Bhabha, and pair annihilation interactions were observed using a pair of lead fluoride Cherenkov calorimeters with custom housings and electronics, adapted from a system used by the A4 parity violation experiment at MAMI. This paper describes the design, calibration, and operation of these detectors. An explanation of the Monte Carlo methods used to simulate the physical processes involved both at the scattering vertices and in the detector apparatus is also included.

  1. MO-A-BRD-06: In Vivo Cherenkov Video Imaging to Verify Whole Breast Irradiation Treatment

    SciTech Connect

    Zhang, R; Glaser, A; Jarvis, L; Gladstone, D; Andreozzi, J; Hitchcock, W; Pogue, B

    2014-06-15

    Purpose: To show in vivo video imaging of Cherenkov emission (Cherenkoscopy) can be acquired in the clinical treatment room without affecting the normal process of external beam radiation therapy (EBRT). Applications of Cherenkoscopy, such as patient positioning, movement tracking, treatment monitoring and superficial dose estimation, were examined. Methods: In a phase 1 clinical trial, including 12 patients undergoing post-lumpectomy whole breast irradiation, Cherenkov emission was imaged with a time-gated ICCD camera synchronized to the radiation pulses, during 10 fractions of the treatment. Images from different treatment days were compared by calculating the 2-D correlations corresponding to the averaged image. An edge detection algorithm was utilized to highlight biological features, such as the blood vessels. Superficial dose deposited at the sampling depth were derived from the Eclipse treatment planning system (TPS) and compared with the Cherenkov images. Skin reactions were graded weekly according to the Common Toxicity Criteria and digital photographs were obtained for comparison. Results: Real time (fps = 4.8) imaging of Cherenkov emission was feasible and feasibility tests indicated that it could be improved to video rate (fps = 30) with system improvements. Dynamic field changes due to fast MLC motion were imaged in real time. The average 2-D correlation was about 0.99, suggesting the stability of this imaging technique and repeatability of patient positioning was outstanding. Edge enhanced images of blood vessels were observed, and could serve as unique biological markers for patient positioning and movement tracking (breathing). Small discrepancies exists between the Cherenkov images and the superficial dose predicted from the TPS but the former agreed better with actual skin reactions than did the latter. Conclusion: Real time Cherenkoscopy imaging during EBRT is a novel imaging tool that could be utilized for patient positioning, movement tracking

  2. Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy

    NASA Astrophysics Data System (ADS)

    Actis, M.; Agnetta, G.; Aharonian, F.; Akhperjanian, A.; Aleksić, J.; Aliu, E.; Allan, D.; Allekotte, I.; Antico, F.; Antonelli, L. A.; Antoranz, P.; Aravantinos, A.; Arlen, T.; Arnaldi, H.; Artmann, S.; Asano, K.; Asorey, H.; Bähr, J.; Bais, A.; Baixeras, C.; Bajtlik, S.; Balis, D.; Bamba, A.; Barbier, C.; Barceló, M.; Barnacka, A.; Barnstedt, J.; Barres de Almeida, U.; Barrio, J. A.; Basso, S.; Bastieri, D.; Bauer, C.; Becerra, J.; Becherini, Y.; Bechtol, K.; Becker, J.; Beckmann, V.; Bednarek, W.; Behera, B.; Beilicke, M.; Belluso, M.; Benallou, M.; Benbow, W.; Berdugo, J.; Berger, K.; Bernardino, T.; Bernlöhr, K.; Biland, A.; Billotta, S.; Bird, T.; Birsin, E.; Bissaldi, E.; Blake, S.; Blanch, O.; Bobkov, A. A.; Bogacz, L.; Bogdan, M.; Boisson, C.; Boix, J.; Bolmont, J.; Bonanno, G.; Bonardi, A.; Bonev, T.; Borkowski, J.; Botner, O.; Bottani, A.; Bourgeat, M.; Boutonnet, C.; Bouvier, A.; Brau-Nogué, S.; Braun, I.; Bretz, T.; Briggs, M. S.; Brun, P.; Brunetti, L.; Buckley, J. H.; Bugaev, V.; Bühler, R.; Bulik, T.; Busetto, G.; Buson, S.; Byrum, K.; Cailles, M.; Cameron, R.; Canestrari, R.; Cantu, S.; Carmona, E.; Carosi, A.; Carr, J.; Carton, P. H.; Casiraghi, M.; Castarede, H.; Catalano, O.; Cavazzani, S.; Cazaux, S.; Cerruti, B.; Cerruti, M.; Chadwick, P. M.; Chiang, J.; Chikawa, M.; Cieślar, M.; Ciesielska, M.; Cillis, A.; Clerc, C.; Colin, P.; Colomé, J.; Compin, M.; Conconi, P.; Connaughton, V.; Conrad, J.; Contreras, J. L.; Coppi, P.; Corlier, M.; Corona, P.; Corpace, O.; Corti, D.; Cortina, J.; Costantini, H.; Cotter, G.; Courty, B.; Couturier, S.; Covino, S.; Croston, J.; Cusumano, G.; Daniel, M. K.; Dazzi, F.; Angelis, A. De; de Cea Del Pozo, E.; de Gouveia Dal Pino, E. M.; de Jager, O.; de La Calle Pérez, I.; de La Vega, G.; de Lotto, B.; de Naurois, M.; de Oña Wilhelmi, E.; de Souza, V.; Decerprit, B.; Deil, C.; Delagnes, E.; Deleglise, G.; Delgado, C.; Dettlaff, T.; di Paolo, A.; di Pierro, F.; Díaz, C.; Dick, J.; Dickinson, H.; Digel, S. W.; Dimitrov, D.; Disset, G.; Djannati-Ataï, A.; Doert, M.; Domainko, W.; Dorner, D.; Doro, M.; Dournaux, J.-L.; Dravins, D.; Drury, L.; Dubois, F.; Dubois, R.; Dubus, G.; Dufour, C.; Durand, D.; Dyks, J.; Dyrda, M.; Edy, E.; Egberts, K.; Eleftheriadis, C.; Elles, S.; Emmanoulopoulos, D.; Enomoto, R.; Ernenwein, J.-P.; Errando, M.; Etchegoyen, A.; Falcone, A. D.; Farakos, K.; Farnier, C.; Federici, S.; Feinstein, F.; Ferenc, D.; Fillin-Martino, E.; Fink, D.; Finley, C.; Finley, J. P.; Firpo, R.; Florin, D.; Föhr, C.; Fokitis, E.; Font, Ll.; Fontaine, G.; Fontana, A.; Förster, A.; Fortson, L.; Fouque, N.; Fransson, C.; Fraser, G. W.; Fresnillo, L.; Fruck, C.; Fujita, Y.; Fukazawa, Y.; Funk, S.; Gäbele, W.; Gabici, S.; Gadola, A.; Galante, N.; Gallant, Y.; García, B.; García López, R. J.; Garrido, D.; Garrido, L.; Gascón, D.; Gasq, C.; Gaug, M.; Gaweda, J.; Geffroy, N.; Ghag, C.; Ghedina, A.; Ghigo, M.; Gianakaki, E.; Giarrusso, S.; Giavitto, G.; Giebels, B.; Giro, E.; Giubilato, P.; Glanzman, T.; Glicenstein, J.-F.; Gochna, M.; Golev, V.; Gómez Berisso, M.; González, A.; González, F.; Grañena, F.; Graciani, R.; Granot, J.; Gredig, R.; Green, A.; Greenshaw, T.; Grimm, O.; Grube, J.; Grudzińska, M.; Grygorczuk, J.; Guarino, V.; Guglielmi, L.; Guilloux, F.; Gunji, S.; Gyuk, G.; Hadasch, D.; Haefner, D.; Hagiwara, R.; Hahn, J.; Hallgren, A.; Hara, S.; Hardcastle, M. J.; Hassan, T.; Haubold, T.; Hauser, M.; Hayashida, M.; Heller, R.; Henri, G.; Hermann, G.; Herrero, A.; Hinton, J. A.; Hoffmann, D.; Hofmann, W.; Hofverberg, P.; Horns, D.; Hrupec, D.; Huan, H.; Huber, B.; Huet, J.-M.; Hughes, G.; Hultquist, K.; Humensky, T. B.; Huppert, J.-F.; Ibarra, A.; Illa, J. M.; Ingjald, J.; Inoue, Y.; Inoue, S.; Ioka, K.; Jablonski, C.; Jacholkowska, A.; Janiak, M.; Jean, P.; Jensen, H.; Jogler, T.; Jung, I.; Kaaret, P.; Kabuki, S.; Kakuwa, J.; Kalkuhl, C.; Kankanyan, R.; Kapala, M.; Karastergiou, A.; Karczewski, M.; Karkar, S.; Karlsson, N.; Kasperek, J.; Katagiri, H.; Katarzyński, K.; Kawanaka, N.; Kȩdziora, B.; Kendziorra, E.; Khélifi, B.; Kieda, D.; Kifune, T.; Kihm, T.; Klepser, S.; Kluźniak, W.; Knapp, J.; Knappy, A. R.; Kneiske, T.; Knödlseder, J.; Köck, F.; Kodani, K.; Kohri, K.; Kokkotas, K.; Komin, N.; Konopelko, A.; Kosack, K.; Kossakowski, R.; Kostka, P.; Kotuła, J.; Kowal, G.; Kozioł, J.; Krähenbühl, T.; Krause, J.; Krawczynski, H.; Krennrich, F.; Kretzschmann, A.; Kubo, H.; Kudryavtsev, V. A.; Kushida, J.; La Barbera, N.; La Parola, V.; La Rosa, G.; López, A.; Lamanna, G.; Laporte, P.; Lavalley, C.; Le Flour, T.; Le Padellec, A.; Lenain, J.-P.; Lessio, L.; Lieunard, B.; Lindfors, E.; Liolios, A.; Lohse, T.; Lombardi, S.; Lopatin, A.; Lorenz, E.; Lubiński, P.; Luz, O.; Lyard, E.; Maccarone, M. C.; Maccarone, T.; Maier, G.; Majumdar, P.; Maltezos, S.; Małkiewicz, P.; Mañá, C.; Manalaysay, A.; Maneva, G.; Mangano, A.; Manigot, P.; Marín, J.; Mariotti, M.; Markoff, S.; Martínez, G.; Martínez, M.; Mastichiadis, A.; Matsumoto, H.; Mattiazzo, S.; Mazin, D.; McComb, T. J. L.; McCubbin, N.; McHardy, I.; Medina, C.; Melkumyan, D.; Mendes, A.; Mertsch, P.; Meucci, M.; Michałowski, J.; Micolon, P.; Mineo, T.; Mirabal, N.; Mirabel, F.; Miranda, J. M.; Mirzoyan, R.; Mizuno, T.; Moal, B.; Moderski, R.; Molinari, E.; Monteiro, I.; Moralejo, A.; Morello, C.; Mori, K.; Motta, G.; Mottez, F.; Moulin, E.; Mukherjee, R.; Munar, P.; Muraishi, H.; Murase, K.; Murphy, A. Stj.; Nagataki, S.; Naito, T.; Nakamori, T.; Nakayama, K.; Naumann, C.; Naumann, D.; Nayman, P.; Nedbal, D.; Niedźwiecki, A.; Niemiec, J.; Nikolaidis, A.; Nishijima, K.; Nolan, S. J.; Nowak, N.; O'Brien, P. T.; Ochoa, I.; Ohira, Y.; Ohishi, M.; Ohka, H.; Okumura, A.; Olivetto, C.; Ong, R. A.; Orito, R.; Orr, M.; Osborne, J. P.; Ostrowski, M.; Otero, L.; Otte, A. N.; Ovcharov, E.; Oya, I.; Oziȩbło, A.; Paiano, S.; Pallota, J.; Panazol, J. L.; Paneque, D.; Panter, M.; Paoletti, R.; Papyan, G.; Paredes, J. M.; Pareschi, G.; Parsons, R. D.; Paz Arribas, M.; Pedaletti, G.; Pepato, A.; Persic, M.; Petrucci, P. O.; Peyaud, B.; Piechocki, W.; Pita, S.; Pivato, G.; Płatos, Ł.; Platzer, R.; Pogosyan, L.; Pohl, M.; Pojmański, G.; Ponz, J. D.; Potter, W.; Prandini, E.; Preece, R.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quel, E.; Quirrenbach, A.; Rajda, P.; Rando, R.; Rataj, M.; Raue, M.; Reimann, C.; Reimann, O.; Reimer, A.; Reimer, O.; Renaud, M.; Renner, S.; Reymond, J.-M.; Rhode, W.; Ribó, M.; Ribordy, M.; Rico, J.; Rieger, F.; Ringegni, P.; Ripken, J.; Ristori, P.; Rivoire, S.; Rob, L.; Rodriguez, S.; Roeser, U.; Romano, P.; Romero, G. E.; Rosier-Lees, S.; Rovero, A. C.; Roy, F.; Royer, S.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Russo, F.; Ryde, F.; Sacco, B.; Saggion, A.; Sahakian, V.; Saito, K.; Saito, T.; Sakaki, N.; Salazar, E.; Salini, A.; Sánchez, F.; Sánchez Conde, M. Á.; Santangelo, A.; Santos, E. M.; Sanuy, A.; Sapozhnikov, L.; Sarkar, S.; Scalzotto, V.; Scapin, V.; Scarcioffolo, M.; Schanz, T.; Schlenstedt, S.; Schlickeiser, R.; Schmidt, T.; Schmoll, J.; Schroedter, M.; Schultz, C.; Schultze, J.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schweizer, T.; Seiradakis, J.; Selmane, S.; Seweryn, K.; Shayduk, M.; Shellard, R. C.; Shibata, T.; Sikora, M.; Silk, J.; Sillanpää, A.; Sitarek, J.; Skole, C.; Smith, N.; Sobczyńska, D.; Sofo Haro, M.; Sol, H.; Spanier, F.; Spiga, D.; Spyrou, S.; Stamatescu, V.; Stamerra, A.; Starling, R. L. C.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steiner, S.; Stergioulas, N.; Sternberger, R.; Stinzing, F.; Stodulski, M.; Straumann, U.; Suárez, A.; Suchenek, M.; Sugawara, R.; Sulanke, K. H.; Sun, S.; Supanitsky, A. D.; Sutcliffe, P.; Szanecki, M.; Szepieniec, T.; Szostek, A.; Szymkowiak, A.; Tagliaferri, G.; Tajima, H.; Takahashi, H.; Takahashi, K.; Takalo, L.; Takami, H.; Talbot, R. G.; Tam, P. H.; Tanaka, M.; Tanimori, T.; Tavani, M.; Tavernet, J.-P.; Tchernin, C.; Tejedor, L. A.; Telezhinsky, I.; Temnikov, P.; Tenzer, C.; Terada, Y.; Terrier, R.; Teshima, M.; Testa, V.; Tibaldo, L.; Tibolla, O.; Tluczykont, M.; Todero Peixoto, C. J.; Tokanai, F.; Tokarz, M.; Toma, K.; Torres, D. F.; Tosti, G.; Totani, T.; Toussenel, F.; Vallania, P.; Vallejo, G.; van der Walt, J.; van Eldik, C.; Vandenbroucke, J.; Vankov, H.; Vasileiadis, G.; Vassiliev, V. V.; Vegas, I.; Venter, L.; Vercellone, S.; Veyssiere, C.; Vialle, J. P.; Videla, M.; Vincent, P.; Vink, J.; Vlahakis, N.; Vlahos, L.; Vogler, P.; Vollhardt, A.; Volpe, F.; von Gunten, H. P.; Vorobiov, S.; Wagner, S.; Wagner, R. M.; Wagner, B.; Wakely, S. P.; Walter, P.; Walter, R.; Warwick, R.; Wawer, P.; Wawrzaszek, R.; Webb, N.; Wegner, P.; Weinstein, A.; Weitzel, Q.; Welsing, R.; Wetteskind, H.; White, R.; Wierzcholska, A.; Wilkinson, M. I.; Williams, D. A.; Winde, M.; Wischnewski, R.; Wiśniewski, Ł.; Wolczko, A.; Wood, M.; Xiong, Q.; Yamamoto, T.; Yamaoka, K.; Yamazaki, R.; Yanagita, S.; Yoffo, B.; Yonetani, M.; Yoshida, A.; Yoshida, T.; Yoshikoshi, T.; Zabalza, V.; Zagdański, A.; Zajczyk, A.; Zdziarski, A.; Zech, A.; Ziȩtara, K.; Ziółkowski, P.; Zitelli, V.; Zychowski, P.

    2011-12-01

    Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.

  3. Design Concepts for the Cherenkov Telescope Array CTA: An Advanced Facility for Ground-Based High-Energy Gamma-Ray Astronomy

    SciTech Connect

    Actis, M

    2012-04-17

    Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.

  4. Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?

    NASA Astrophysics Data System (ADS)

    Sánchez-Conde, Miguel A.; Cannoni, Mirco; Zandanel, Fabio; Gómez, Mario E.; Prada, Francisco

    2011-12-01

    In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

  5. Dark Matter Searches with Cherenkov Telescopes: Nearby Dwarf Galaxies or Local Galaxy Clusters?

    SciTech Connect

    Sanchez-Conde, Miguel A.; Cannoni, Mirco; Zandanel, Fabio; Gomez, Mario E.; Prada, Francisco; /IAA, Granada

    2012-06-06

    In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

  6. Performance in space of the AMS-02 RICH detector

    NASA Astrophysics Data System (ADS)

    Giovacchini, F.

    2014-12-01

    AMS-02 was successfully installed on the International Space Station (ISS) in May 2011, to perform precise measurements of galactic cosmic rays in the 100 MV to few TV magnetic rigidity range. Among several specialized sub-detectors, AMS-02 includes a Ring Imaging Cherenkov detector (RICH), which provides a precise measurement of the particle charge and velocity. The Cherenkov light is produced in a radiator made of silica aerogel and sodium fluoride and collected by means of an array of photomultiplier tubes. Since its launch to space, the detector has been taking data without failures; its functionality and data integrity are monitored and show stable response. In order to achieve the optimal detector performance, calibrations have been performed to account for the dependence of the photodetectors response on temperature and for effective non-uniformities in the detector. The knowledge gathered of the photon yield at the percent level resulted in a charge resolution of 0.3 charge units for He and 0.5 charge units for Si ions. The required precision in the measurements of the particle velocity at the per mil level demanded a more accurate determination of the aerogel refractive index. A map of the aerogel radiator refractive index has been directly inferred from in-flight high statistics data with a precision of Δn / n < 2 ×10-5 on average and its stability with time has also been checked. Finally, a velocity resolution of ~ 0.8 ×10-3 for He and ~ 0.5 ×10-3 for Z > 5 ions has been obtained.

  7. Panofsky Prize Lecture: Evidence for Oscillation of Atmospheric Neutrinos

    NASA Astrophysics Data System (ADS)

    Totsuka, Yoji

    2002-04-01

    Atmospheric neutrinos are decay products of pions and kaons (and of their decay products muons) produced by nuclear interactions of cosmic rays with air nuclei. Though their flux is not known well, only within 20 %, physics quantities that are independent of the flux uncertainty exist. The ratio of the number of muon neutrinos to the number of electron neutrinos is estimated to be accurate within 5 %. The other quantity is the shape of the zenith-angle distribution. Kamiokande and Super-Kamiokande are water Cherenkov detectors with 3,000 ton and 50,000 ton pure water, respectively. Kamiokande was operational in 1983 - 1996, and Super-K in 1996 - 2001 and 2003 - in future. We had already noted in 1988 that the observed μ/e ratio, which represented ν_mu/ν_e, was smaller by about 40 %. Later in 1994 we noted that the zenith angle distribution of muon neutrinos was strongly distorted, namely much fewer muons observed in the upward direction, while downward-going muons were what we expected. Electrons were quite normal. In 1996 Super-Kamiokande was ready. Its fiducial volume is 22.5 kton, much larger than Kamiokande's 1.04 kton. In 1998 based on 25.5 kton years of data we presented convincing results on the small μ/e ratio which was caused by fewer number of muons in the upward direction. The essential feature of the observed anomaly was that the disappearance of muon neutrinos depended strongly on their path length and on their energies. Electrons showed no anomaly within the experimental limit. These results were quantitatively and almost uniquely explained by oscillation of muon neutrinos to tau neutrinos, thus evidence for the finite but tiny mass of neutrinos.

  8. Pyroelectric detectors

    NASA Technical Reports Server (NTRS)

    Haller, Eugene E.; Beeman, Jeffrey; Hansen, William L.; Hubbard, G. Scott; Mcmurray, Robert E., Jr.

    1990-01-01

    The multi-agency, long-term Global Change programs, and specifically NASA's Earth Observing system, will require some new and advanced photon detector technology which must be specifically tailored for long-term stability, broad spectral range, cooling constraints, and other parameters. Whereas MCT and GaAs alloy based photovoltaic detectors and detector arrays reach most impressive results to wavelengths as long as 12 microns when cooled to below 70 K, other materials, such as ferroelectrics and pyroelectrics, appear to offer special opportunities beyond 12 microns and above 70 K. These materials have found very broad use in a wide variety of room temperature applications. Little is known about these classes of materials at sub-room temperatures and no photon detector results have been reported. From the limited information available, researchers conclude that the room temperature values of D asterisk greater than or equal to 10(exp 9) cm Hz(exp 1/2)/W may be improved by one to two orders of magnitude upon cooling to temperatures around 70 K. Improvements of up to one order of magnitude appear feasible for temperatures achievable by passive cooling. The flat detector response over a wavelength range reaching from the visible to beyond 50 microns, which is an intrinsic advantage of bolometric devices, makes for easy calibration. The fact that these materials have been developed for reduced temperature applications makes ferro- and pyroelectric materials most attractive candidates for serious exploration.

  9. Integrated Dual Imaging Detector

    NASA Technical Reports Server (NTRS)

    Rust, David M.

    1999-01-01

    A new type of image detector was designed to simultaneously analyze the polarization of light at all picture elements in a scene. The integrated Dual Imaging detector (IDID) consists of a lenslet array and a polarizing beamsplitter bonded to a commercial charge coupled device (CCD). The IDID simplifies the design and operation of solar vector magnetographs and the imaging polarimeters and spectroscopic imagers used, for example, in atmosphere and solar research. When used in a solar telescope, the vector magnetic fields on the solar surface. Other applications include environmental monitoring, robot vision, and medical diagnoses (through the eye). Innovations in the IDID include (1) two interleaved imaging arrays (one for each polarization plane); (2) large dynamic range (well depth of 10(exp 5) electrons per pixel); (3) simultaneous readout and display of both images; and (4) laptop computer signal processing to produce polarization maps in field situations.

  10. PHASE DETECTOR

    DOEpatents

    Kippenhan, D.O.

    1959-09-01

    A phase detector circuit is described for use at very high frequencies of the order of 50 megacycles. The detector circuit includes a pair of rectifiers inverted relative to each other. One voltage to be compared is applied to the two rectifiers in phase opposition and the other voltage to be compared is commonly applied to the two rectifiers. The two result:ng d-c voltages derived from the rectifiers are combined in phase opposition to produce a single d-c voltage having amplitude and polarity characteristics dependent upon the phase relation between the signals to be compared. Principal novelty resides in the employment of a half-wave transmission line to derive the phase opposing signals from the first voltage to be compared for application to the two rectifiers in place of the transformer commonly utilized for such purpose in phase detector circuits for operation at lower frequency.

  11. Scintillation Detector for the Measurement of Ultra-Heavy Cosmic Rays on the Super-TIGER Experiment

    NASA Technical Reports Server (NTRS)

    Link, Jason

    2011-01-01

    We discuss the design and construction of the scintillation detectors for the Super-TIGER experiment. Super-TIGER is a large-area (5.4sq m) balloon-borne experiment designed to measure the abundances of cosmic-ray nuclei between Z= 10 and Z=56. It is based on the successful TIGER experiment that flew in Antarctica in 2001 and 2003. Super-TIGER has three layers of scintillation detectors, two Cherenkov detectors and a scintillating fiber hodoscope. The scintillation detector employs four wavelength shifter bars surrounding the edges of the scintillator to collect the light from particles traversing the detector. PMTs are optically coupled at both ends of the bars for light collection. We report on laboratory performance of the scintillation counters using muons. In addition we discuss the design challenges and detector response over this broad charge range including the effect of scintilator saturation.

  12. Hydrogen detector

    DOEpatents

    Kanegae, Naomichi; Ikemoto, Ichiro

    1980-01-01

    A hydrogen detector of the type in which the interior of the detector is partitioned by a metal membrane into a fluid section and a vacuum section. Two units of the metal membrane are provided and vacuum pipes are provided independently in connection to the respective units of the metal membrane. One of the vacuum pipes is connected to a vacuum gauge for static equilibrium operation while the other vacuum pipe is connected to an ion pump or a set of an ion pump and a vacuum gauge both designed for dynamic equilibrium operation.

  13. Microwave detector

    DOEpatents

    Meldner, Heiner W.; Cusson, Ronald Y.; Johnson, Ray M.

    1986-01-01

    A microwave detector (10) is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite (26, 28) produces a magnetization field flux that links a B-dot loop (16, 20). The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means (18, 22) are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

  14. Microwave detector

    DOEpatents

    Meldner, H.W.; Cusson, R.Y.; Johnson, R.M.

    1985-02-08

    A microwave detector is provided for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations. A biased ferrite produces a magnetization field flux that links a B-dot loop. The magnetic field of the microwave pulse participates in the formation of the magnetization field flux. High-frequency insensitive means are provided for measuring electric voltage or current induced in the B-dot loop. The recorded output of the detector is proportional to the time derivative of the square of the envelope shape of the microwave pulse.

  15. Silicon Detectors

    NASA Astrophysics Data System (ADS)

    Sadrozinski, Hartmut

    2014-03-01

    The use of silicon detectors has experienced an exponential growth in accelerator and space based experiments, similar to trends in the semiconductor industry as a whole, usually paraphrased as ``Moore's Law.'' Some of the essentials for this phenomenon will be presented, together with examples of the exciting science results which it enabled. With the establishment of a ``semiconductor culture'' in universities and laboratories around the world, an increased understanding of the sensors results in thinner, faster, more radiation-resistant detectors, spawning an amazing wealth of new technologies and applications, which will be the main subject of the presentation.

  16. Microwave detector

    SciTech Connect

    Meldner, H.W.; Cusson, R.Y.; Johnson, R.M.

    1986-12-02

    A detector is described for measuring the envelope shape of a microwave pulse comprised of high-frequency oscillations, the detector comprising: a B-dot loop linking the magnetic field of the microwave pulse; a biased ferrite, that produces a magnetization field flux that links the B-dot loop. The ferrite is positioned within the B-dot loop so that the magnetic field of the microwave pulse interacts with the ferrite and thereby participates in the formation of the magnetization field flux; and high-frequency insensitive means for measuring electric voltage or current induced in the B-dot loop.

  17. SU-E-CAMPUS-T-04: Measurement of Proton Pencil Beam Spot Profile Using Cherenkov Radiation in Two Dimensional Optical Fiber Arrays

    SciTech Connect

    Kim, M; SHIN, D; Park, J; Lim, Y; Lee, S; Kim, J; Son, J; Hwang, U

    2014-06-15

    Purpose: Proton therapy aims to deliver a high dose in a well-defined target volume while sparing the healthy surrounding tissues thanks to their inherent depth dose characteristic (Bragg peak). In proton therapy, several techniques can be used to deliver the dose into the target volume. The one that allows the best conformity with the tumor, is called PBS (Pencil Beam Scanning). The measurement of the proton pencil beam spot profile (spot size) and position is very important for the accurate delivery of dose to the target volume with a good conformity. Methods: We have developed a fine segmented detector array to monitor the PBS. A prototype beam monitor using Cherenkov radiation in clear plastic optical fibers (cPOF) has been developed for continuous display of the pencil beam status during the therapeutic proton Pencil Beam Scanning mode operation. The benefit of using Cherenkov radiation is that the optical output is linear to the dose. Pedestal substraction and the gain adjustment between channels are performed. Spot profiles of various pencil beam energies(100 MeV to 226 MeV) are measured. Two dimensional gaussian fit is used to analyze the beam width and the spot center. The results are compared with that of Lynx(Scintillator-based sensor with CCD camera) and EBT3 Film. Results: The measured gaussian widths using fiber array system changes from 13 to 5 mm for the beam energies from 100 to 226 MeV. The results agree well with Lynx and Film within the systematic error. Conclusion: The results demonstrate good monitoring capability of the system. Not only measuing the spot profile but also monitoring dose map by accumulating each spot measurement is available. The x-y monitoing system with 128 channel readout will be mounted to the snout for the in-situ real time monitoring.

  18. Calibration of the Pierre Auger Observatory fluorescence detectors and the effect on measurements

    NASA Astrophysics Data System (ADS)

    Gookin, Ben

    The Pierre Auger Observatory is a high-energy cosmic ray observatory located in Malargue, Mendoza, Argentina. It is used to probe the highest energy particles in the Universe, with energies greater than 1018 eV, which strike the Earth constantly. The observatory uses two techniques to observe the air shower initiated by a cosmic ray: a surface detector composed of an array of more than 1600 water Cherenkov tanks covering 3000 km2, and 27 nitrogen fluorescence telescopes overlooking this array. The Cherenkov detectors run all the time and therefore have high statistics on the air showers. The fluorescence detectors run only on clear moonless nights, but observe the longitudinal development of the air shower and make a calorimetric measure of its energy. The energy measurement from the the fluorescence detectors is used to cross calibrate the surface detectors, and makes the measurements made by the Auger Observatory surface detector highly model-independent. The calibration of the fluorescence detectors is then of the utmost importance to the measurements of the Observatory. Described here are the methods of the absolute and multi-wavelength calibration of the fluorescence detectors, and improvements in each leading to a reduction in calibration uncertainties to 4% and 3.5%, respectively. Also presented here are the effects of introducing a new, and more detailed, multi-wavelength calibration on the fluorescence detector energy estimation and the depth of the air shower maximum measurement, leading to a change of 1+-0.03% in the absolute energy scale at 1018 eV, and a negligible change in the measurement on shower maximum.

  19. Vertex detectors

    SciTech Connect

    Lueth, V.

    1992-07-01

    The purpose of a vertex detector is to measure position and angles of charged particle tracks to sufficient precision so as to be able to separate tracks originating from decay vertices from those produced at the interaction vertex. Such measurements are interesting because they permit the detection of weakly decaying particles with lifetimes down to 10{sup {minus}13} s, among them the {tau} lepton and charm and beauty hadrons. These two lectures are intended to introduce the reader to the different techniques for the detection of secondary vertices that have been developed over the past decades. The first lecture includes a brief introduction to the methods used to detect secondary vertices and to estimate particle lifetimes. It describes the traditional technologies, based on photographic recording in emulsions and on film of bubble chambers, and introduces fast electronic registration of signals derived from scintillating fibers, drift chambers and gaseous micro-strip chambers. The second lecture is devoted to solid state detectors. It begins with a brief introduction into semiconductor devices, and then describes the application of large arrays of strip and pixel diodes for charged particle tracking. These lectures can only serve as an introduction the topic of vertex detectors. Time and space do not allow for an in-depth coverage of many of the interesting aspects of vertex detector design and operation.

  20. Poster — Thur Eve — 18: Cherenkov Emission By High-Energy Radiation Therapy Beams: A Characterization Study

    SciTech Connect

    Zlateva, Y.; El Naqa, I.; Quitoriano, N.

    2014-08-15

    We investigate Cherenkov emission (CE) by radiotherapy beams via radiation dose-versus-CE correlation analyses, CE detection optimization by means of a spectral shift towards the near-infrared (NIR) window of biological tissue, and comparison of CE to on-board MV imaging. Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissue-simulating phantom composed of water, Intralipid®, and beef blood; plastic phantom with solid water insert. The detector system comprises an optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated CCD. The NIR shift was carried out with CdSe/ZnS quantum dots (QDs), emitting at (650±10) nm. CE and MV images were acquired with a CMOS camera and electronic portal imaging device. MC and experimental studies indicate a strong linear dose-CE correlation (Pearson coefficient > 0.99). CE by an 18-MeV beam was effectively NIR-shifted in water and a tissue-simulating phantom, exhibiting a significant increase at 650 nm for QD depths up to 10 mm. CE images exhibited relative contrast superior to MV images by a factor of 30. Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing and QDs can be used to improve CE detectability, potentially yielding image quality superior to MV imaging for the case of low-density-variability, low-optical-attenuation materials (ex: breast/oropharynx). Ongoing work involves microenvironment functionalization of QDs and application of multi-channel spectrometry for simultaneous acquisition of dosimetric and tumor oxygenation signals.

  1. Performance of the fluorescence detectors of the pierre auger observatory

    SciTech Connect

    Bellido, Jose A.; /Adelaide U.

    2005-08-01

    Fluorescence detectors of the Pierre Auger Observatory have been operating in a stable manner since January 2004. After a brief review of the physical characteristics of the detectors, the associated atmospheric monitoring, the calibration infrastructure and the detector aperture, we will describe the steps required for the reconstruction of fluorescence event data, with emphasis on the shower profile parameters and primary energy.

  2. Cherenkov friction on a neutral particle moving parallel to a dielectric.

    PubMed

    Pieplow, Gregor; Henkel, Carsten

    2015-06-01

    We describe a simple mechanism of quantum friction for a particle moving parallel to a dielectric, based on a fully relativistic framework and the assumption of local equilibrium. The Cherenkov effect explains how the bare ground state becomes globally unstable and how fluctuations of the electromagnetic field and the particle's dipole are converted into pairs of excitations. Modeling the particle as a silver nano-sphere, we investigate the spectrum of the force and its velocity dependence. We find that the damping of the plasmon resonance in the silver particle has a relatively strong impact near the Cherenkov threshold velocity. We also present an expansion of the friction force near the threshold velocity for both damped and undamped particles. PMID:25965087

  3. An overview on mirrors for Cherenkov telescopes manufactured by glass cold-shaping technology

    NASA Astrophysics Data System (ADS)

    Canestrari, Rodolfo; Sironi, Giorgia

    2015-09-01

    The cold glass-slumping technique is a low cost processing developed at INAF-Osservatorio Astronomico di Brera for the manufacturing of mirrors for Cherenkov telescopes. This technology is based on the shaping of thin glass foils by means of bending at room temperature. The glass foils are thus assembled into a sandwich structure for retaining the imposed shape by the use of a honeycomb core. The mirrors so manufactured employ commercial off-the-shelf materials thus allowing a competitive cost and production time. They show very low weight, rigidity and environmental robustness. In this contribution we give an overview on the most recent results achieved from the adoption of the cold-shaping technology to different projects of Cherenkov telescopes. We show the variety of optical shapes implemented ranging from those spherical with long radius of curvature up to the most curved free form ones.

  4. LPM Interference and Cherenkov-like Gluon Bremsstrahlung in DenseMatter

    SciTech Connect

    Majumder, Abhijit; Wang, Xin-Nian

    2005-07-26

    Gluon bremsstrahlung induced by multiple parton scattering in a finite dense medium has a unique angular distribution with respect to the initial parton direction. A dead-cone structure with an opening angle; theta2{sub 0}; approx 2(1-z)/(zLE) for gluons with fractional energy z arises from the Landau-Pomeran chuck-Migdal (LPM) interference. In a medium where the gluon's dielectric constant is; epsilon>1, the LPM interference pattern is shown to become Cherenkov-like with an increased opening angle determined by the dielectric constant$/cos2/theta{sub c}=z+(1-z)//epsilon$. For a large dielectric constant/epsilon; gg 1+2/z2LE, the corresponding total radiative parton energy loss is about twice that from normal gluon bremsstrahlung. Implications of this Cherenkov-like gluon bremsstrahlung to the jet correlation pattern in high-energy heavy-ion collisions is discussed.

  5. Coaxial configuration for a wide-bandwidth dielectric Cherenkov maser amplifier

    SciTech Connect

    Shlapakovskii, A.S.

    1995-11-01

    A coaxial dielectric-lined waveguide is considered as the slow-wave supporting structure of the dielectric Cherenkov maser amplifier. Its basic ``quasi-TEM`` mode has very weak dispersion at phase velocities closed to the speed of light. This feature is attractive since it may provide the amplifier with very large bandwidth values. The system dispersion relation is derived for an infinitely thin hollow electron beam within a coaxial waveguide loaded with one dielectric liner located at either inner or outer conductor. Spatial growth rates are calculated numerically at various parameters of the slow-wave structure and electron beam. Bandwidth dependences on parameters are examined compared to those of the conventional dielectric Cherenkov maser configuration Constructive peculiarities of the coaxial configuration allowing original approaches to the problems of electron beam dumping and RF input and output matching are discussed.

  6. The ASTRI project within Cherenkov Telescope Array: data analysis and archiving

    NASA Astrophysics Data System (ADS)

    Antonelli, Lucio Angelo; Bastieri, Denis; Capalbi, Milvia; Carosi, Alessandro; Catalano, Osvaldo; Di Paola, Andrea; Gallozzi, Stefano; Lombardi, Saverio; Lucarelli, Fabrizio; Perri, Matteo; Testa, Vincenzo

    2014-07-01

    ASTRI is the flagship project of INAF (Italian National Institute for Astrophysics) mainly devoted to the development of Cherenkov small-size dual-mirror telescopes (SST-2M) in the framework of the international Cherenkov Telescope Array (CTA) Project. ASTRI SST-2M is an end-to-end prototype including scientific and technical operations as well as the related data analysis and archiving activities. We present here the ASTRI data handling and archiving system: it is responsible for both the on-site and off-site data processing and archiving. All the scientific, calibration, and engineering ASTRI data will be stored and organized in dedicated archives aimed to provide access to both the monitoring and data analysis systems.

  7. Photonic chip-based optical frequency comb using soliton Cherenkov radiation.

    PubMed

    Brasch, V; Geiselmann, M; Herr, T; Lihachev, G; Pfeiffer, M H P; Gorodetsky, M L; Kippenberg, T J

    2016-01-22

    Optical solitons are propagating pulses of light that retain their shape because nonlinearity and dispersion balance each other. In the presence of higher-order dispersion, optical solitons can emit dispersive waves via the process of soliton Cherenkov radiation. This process underlies supercontinuum generation and is of critical importance in frequency metrology. Using a continuous wave-pumped, dispersion-engineered, integrated silicon nitride microresonator, we generated continuously circulating temporal dissipative Kerr solitons. The presence of higher-order dispersion led to the emission of red-shifted soliton Cherenkov radiation. The output corresponds to a fully coherent optical frequency comb that spans two-thirds of an octave and whose phase we were able to stabilize to the sub-Hertz level. By preserving coherence over a broad spectral bandwidth, our device offers the opportunity to develop compact on-chip frequency combs for frequency metrology or spectroscopy. PMID:26721682

  8. Spin-Cherenkov effect in a magnetic nanostrip with interfacial Dzyaloshinskii-Moriya interaction

    PubMed Central

    Xia, Jing; Zhang, Xichao; Yan, Ming; Zhao, Weisheng; Zhou, Yan

    2016-01-01

    Spin-Cherenkov effect enables strong excitations of spin waves (SWs) with nonlinear wave dispersions. The Dzyaloshinskii-Moriya interaction (DMI) results in anisotropy and nonreciprocity of SWs propagation. In this work, we study the effect of the interfacial DMI on SW Cherenkov excitations in permalloy thin-film strips within the framework of micromagnetism. By performing micromagnetic simulations, it is shown that coherent SWs are excited when the velocity of a moving magnetic source exceeds the propagation velocity of the SWs. Moreover, the threshold velocity of the moving magnetic source with finite DMI can be reduced compared to the case of zero DMI. It thereby provides a promising route towards efficient spin wave generation and propagation, with potential applications in spintronic and magnonic devices. PMID:27143311

  9. Cherenkov radiation from a relativistic annular electron beam propagating through a dielectric loaded waveguide

    NASA Astrophysics Data System (ADS)

    Uhm, H. S.

    1981-11-01

    The stability properties of the free-streaming mode (space-charge wave) in a relativistic annular electron beam with radius R sub 0 propagating through a dielectric loaded waveguide is studied in connection with the Cherenkov radiation. The stability analysis is carried out within the framework of the linearized Vlasov-Maxwell equations for an electron distribution function, where all electrons have a Lorentzian distribution in the axial canonical momentum. One of the most significant features of the analysis is that, for some ranges of physical parameters, a strong mode coupling between the vacuum dielectric waveguide and free streaming modes occurs, exhibiting possibilities of a Cherenkov radiation. It is found that the typical maximum growth rate of instability is a few percent of c/R sub 0, c being the speed of light in vacuo.

  10. Vacuum Cherenkov radiation in quantum electrodynamics with high-energy Lorentz violation

    SciTech Connect

    Anselmi, Damiano; Taiuti, Martina

    2011-03-01

    We study phenomena predicted by a renormalizable, CPT invariant extension of the standard model that contains higher-dimensional operators and violates Lorentz symmetry explicitly at energies greater than some scale {Lambda}{sub L}. In particular, we consider the Cherenkov radiation in vacuo. In a rather general class of dispersion relations, there exists an energy threshold above which radiation is emitted. The threshold is enhanced in composite particles by a sort of kinematic screening mechanism. We study the energy loss and compare the predictions of our model with known experimental bounds on Lorentz violating parameters and observations of ultrahigh-energy cosmic rays. We argue that the scale of Lorentz violation {Lambda}{sub L} (with preserved CPT invariance) can be smaller than the Planck scale, actually as small as 10{sup 14}-10{sup 15} GeV. Our model also predicts the Cherenkov radiation of neutral particles.

  11. Determining atmospheric aerosol content with an infra-red radiometer

    NASA Astrophysics Data System (ADS)

    Daniel, M. K.; Vasileiadis, G.; H. E. S. S. Collaboration

    2012-12-01

    The attenuation of atmospheric Cherenkov photons is dominated by two processes: Rayleigh scattering from the molecular component and Mie scattering from the aerosol component. Aerosols are expected to contribute up to 30 Wm-2 to the emission profile of the atmosphere, equivalent to a difference of ~ 20°C to the clear sky brightness temperature under normal conditions. Here we investigate the aerosol contribution of the measured sky brightness temperature at the H.E.S.S. site; compare it to effective changes in the telescope trigger rates; and discuss how it can be used to provide an assessment of sky clarity that is unambiguously free of telescope systematics.

  12. The ASTRI SST-2M prototype for the next generation of Cherenkov telescopes: a single framework approach from requirement analysis to integration and verification strategy definition

    NASA Astrophysics Data System (ADS)

    Fiorini, Mauro; La Palombara, Nicola; Stringhetti, Luca; Canestrari, Rodolfo; Catalano, Osvaldo; Giro, Enrico; Leto, Giuseppe; Maccarone, Maria Concetta; Pareschi, Giovanni; Tosti, Gino; Vercellone, Stefano

    2014-08-01

    ASTRI is a flagship project of the Italian Ministry of Education, University and Research, which aims to develop an endto- end prototype of one of the three types of telescopes to be part of the Cherenkov Telescope Array (CTA), an observatory which will be the main representative of the next generation of Imaging Atmospheric Cherenkov Telescopes. The ASTRI project, led by the Italian National Institute of Astrophysics (INAF), has proposed an original design for the Small Size Telescope, which is aimed to explore the uppermost end of the Very High Energy domain up to about few hundreds of TeV with unprecedented sensitivity, angular resolution and imaging quality. It is characterized by challenging and innovative technological solutions which will be adopted for the first time in a Cherenkov telescope: a dual-mirror Schwarzschild-Couder configuration, a modular, light and compact camera based on silicon photomultipliers, and a front-end electronic based on a specifically designed ASIC. The end-to-end project is also including all the data-analysis software and the data archive. In this paper we describe the process followed to derive the ASTRI specifications from the CTA general requirements, a process which had to take into proper account the impact on the telescope design of the different types of the CTA requirements (performance, environment, reliability-availability-maintenance, etc.). We also describe the strategy adopted to perform the specification verification, which will be based on different methods (inspection, analysis, certification, and test) in order to demonstrate the telescope compliance with the CTA requirements. Finally we describe the integration planning of the prototype assemblies (structure, mirrors, camera, control software, auxiliary items) and the test planning of the end-to-end telescope. The approach followed by the ASTRI project is to have all the information needed to report the verification process along all project stages in a single

  13. Nonlinear quantum theory of stimulated Cherenkov radiation of transverse electromagnetic waves from a low-density relativistic electron beam in a dielectric medium

    SciTech Connect

    Bobylev, Yu. B.; Kuzelev, M. V.

    2012-06-15

    A nonlinear quantum theory of stimulated Cherenkov radiation of transverse electromagnetic waves from a low-density relativistic electron beam in an isotropic dielectric medium is presented. A quantum model based on the Klein-Gordon equation is used. The growth rates of beam instabilities caused by the effect of stimulated Cherenkov radiation have been determined in the linear approximation. Mechanisms of the nonlinear saturation of relativistic quantum Cherenkov beam instabilities have been analyzed and the corresponding analytical solutions have been obtained.

  14. Neutron detector

    DOEpatents

    Stephan, Andrew C.; Jardret; Vincent D.

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  15. Neutron detector

    SciTech Connect

    Stephan, Andrew C; Jardret, Vincent D

    2009-04-07

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  16. Angle detector

    NASA Technical Reports Server (NTRS)

    Parra, G. T. (Inventor)

    1978-01-01

    An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

  17. Flame Detector

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Scientific Instruments, Inc. has now developed a second generation, commercially available instrument to detect flames in hazardous environments, typically refineries, chemical plants and offshore drilling platforms. The Model 74000 detector incorporates a sensing circuit that detects UV radiation in a 100 degree conical field of view extending as far as 250 feet from the instrument. It operates in a bandwidth that makes it virtually 'blind' to solar radiation while affording extremely high sensitivity to ultraviolet flame detection. A 'windowing' technique accurately discriminates between background UV radiation and ultraviolet emitted from an actual flame, hence the user is assured of no false alarms. Model 7410CP is a combination controller and annunciator panel designed to monitor and control as many as 24 flame detectors. *Model 74000 is no longer being manufactured.

  18. Cherenkov radiation fluence estimates in tissue for molecular imaging and therapy applications

    NASA Astrophysics Data System (ADS)

    Glaser, Adam K.; Zhang, Rongxiao; Andreozzi, Jacqueline; Gladstone, David; Pogue, Brian

    2016-03-01

    Cherenkov radiation has emerged as a novel source of light with a number of applications in the biomedical sciences. It's unique properties, including its broadband emission spectrum, spectral weighting in the ultraviolet and blue wavebands, and local generation of light within a given tissue have made it an attractive source of light for techniques ranging from widefield imaging to oximetry and phototherapy. To help guide the future development of this field in the context of molecular imaging, quantitative estimates of the light fluence rates of Cherenkov radiation from a number of radionuclide and external radiotherapy beams in tissue was explored for the first time. Using Monte Carlo simulations, these values were found to be on the order of 0.1 - 1 nW/cm2 per MBq/g for radionuclides and 1 - 10 μW/cm2 per Gy/sec for external radiotherapy beams, dependent on the given waveband and optical properties. For phototherapy applications, the total light fluence was found to be on the order of nJ/cm2 for radionuclides, and mJ/cm2 for radiotherapy beams. To validate these findings, experimental validation was completed with an MV x-ray photon beam incident onto a tissue phantom, confirming the magnitudes of the simulation values. The results indicate that diagnostic potential is reasonable for Cherenkov excitation of molecular probes, but phototherapy may remain elusive at these relatively low fluence values.

  19. Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

    SciTech Connect

    Jarvis, Lesley A.; Zhang, Rongxiao; Gladstone, David J.; Jiang, Shudong; Hitchcock, Whitney; Friedman, Oscar D.; Glaser, Adam K.; Jermyn, Michael; Pogue, Brian W.

    2014-07-01

    Purpose: To determine whether Cherenkov light imaging can visualize radiation therapy in real time during breast radiation therapy. Methods and Materials: An intensified charge-coupled device (CCD) camera was synchronized to the 3.25-μs radiation pulses of the clinical linear accelerator with the intensifier set × 100. Cherenkov images were acquired continuously (2.8 frames/s) during fractionated whole breast irradiation with each frame an accumulation of 100 radiation pulses (approximately 5 monitor units). Results: The first patient images ever created are used to illustrate that Cherenkov emission can be visualized as a video during conditions typical for breast radiation therapy, even with complex treatment plans, mixed energies, and modulated treatment fields. Images were generated correlating to the superficial dose received by the patient and potentially the location of the resulting skin reactions. Major blood vessels are visible in the image, providing the potential to use these as biological landmarks for improved geometric accuracy. The potential for this system to detect radiation therapy misadministrations, which can result from hardware malfunction or patient positioning setup errors during individual fractions, is shown. Conclusions: Cherenkoscopy is a unique method for visualizing surface dose resulting in real-time quality control. We propose that this system could detect radiation therapy errors in everyday clinical practice at a time when these errors can be corrected to result in improved safety and quality of radiation therapy.

  20. The prototype detection unit of the KM3NeT detector

    NASA Astrophysics Data System (ADS)

    Adrián-Martínez, S.; Ageron, M.; Aharonian, F.; Aiello, S.; Albert, A.; Ameli, F.; Anassontzis, E. G.; Androulakis, G. C.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Avgitas, T.; Balasi, K.; Band, H.; Barbarino, G.; Barbarito, E.; Barbato, F.; Baret, B.; Baron, S.; Barrios, J.; Belias, A.; Berbee, E.; van den Berg, A. M.; Berkien, A.; Bertin, V.; Beurthey, S.; van Beveren, V.; Beverini, N.; Biagi, S.; Biagioni, A.; Bianucci, S.; Billault, M.; Birbas, A.; Boer Rookhuizen, H.; Bormuth, R.; Bouché, V.; Bouhadef, B.; Bourlis, G.; Boutonnet, C.; Bouwhuis, M.; Bozza, C.; Bruijn, R.; Brunner, J.; Cacopardo, G.; Caillat, L.; Calamai, M.; Calvo, D.; Capone, A.; Caramete, L.; Caruso, F.; Cecchini, S.; Ceres, A.; Cereseto, R.; Champion, C.; Château, F.; Chiarusi, T.; Christopoulou, B.; Circella, M.; Classen, L.; Cocimano, R.; Coleiro, A.; Colonges, S.; Coniglione, R.; Cosquer, A.; Costa, M.; Coyle, P.; Creusot, A.; Cuttone, G.; D'Amato, C.; D'Amico, A.; De Bonis, G.; De Rosa, G.; Deniskina, N.; Destelle, J.-J.; Distefano, C.; Di Capua, F.; Donzaud, C.; Dornic, D.; Dorosti-Hasankiadeh, Q.; Drakopoulou, E.; Drouhin, D.; Drury, L.; Durand, D.; Eberl, T.; Elsaesser, D.; Enzenhöfer, A.; Fermani, P.; Fusco, L. A.; Gajanana, D.; Gal, T.; Galatà, S.; Garufi, F.; Gebyehu, M.; Giordano, V.; Gizani, N.; Gracia Ruiz, R.; Graf, K.; Grasso, R.; Grella, G.; Grmek, A.; Habel, R.; van Haren, H.; Heid, T.; Heijboer, A.; Heine, E.; Henry, S.; Hernández-Rey, J. J.; Herold, B.; Hevinga, M. A.; van der Hoek, M.; Hofestädt, J.; Hogenbirk, J.; Hugon, C.; Hößl, J.; Imbesi, M.; James, C. W.; Jansweijer, P.; Jochum, J.; de Jong, M.; Jongen, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Kappos, E.; Katz, U.; Kavatsyuk, O.; Keller, P.; Kieft, G.; Koffeman, E.; Kok, H.; Kooijman, P.; Koopstra, J.; Korporaal, A.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Larosa, G.; Lattuada, D.; Le Provost, H.; Leismüller, K. P.; Leisos, A.; Lenis, D.; Leonora, E.; Lindsey Clark, M.; Llorens Alvarez, C. D.; Löhner, H.; Lonardo, A.; Loucatos, S.; Louis, F.; Maccioni, E.; Mannheim, K.; Manolopoulos, K.; Margiotta, A.; Mariş, O.; Markou, C.; Martínez-Mora, J. A.; Martini, A.; Masullo, R.; Melis, K. W.; Michael, T.; Migliozzi, P.; Migneco, E.; Miraglia, A.; Mollo, C. M.; Mongelli, M.; Morganti, M.; Mos, S.; Moudden, Y.; Musico, P.; Musumeci, M.; Nicolaou, C.; Nicolau, C. A.; Orlando, A.; Orzelli, A.; Papaikonomou, A.; Papaleo, R.; Păvălaş, G. E.; Peek, H.; Pellegrino, C.; Pellegriti, M. G.; Perrina, C.; Piattelli, P.; Pikounis, K.; Popa, V.; Pradier, Th.; Priede, M.; Pühlhofer, G.; Pulvirenti, S.; Racca, C.; Raffaelli, F.; Randazzo, N.; Rapidis, P. A.; Razis, P.; Real, D.; Resvanis, L.; Reubelt, J.; Riccobene, G.; Rovelli, A.; Saldaña, M.; Samtleben, D. F. E.; Sanguineti, M.; Santangelo, A.; Sapienza, P.; Schmelling, J.; Schnabel, J.; Sciacca, V.; Sedita, M.; Seitz, T.; Sgura, I.; Simeone, F.; Sipala, V.; Spitaleri, A.; Spurio, M.; Stavropoulos, G.; Steijger, J.; Stolarczyk, T.; Stransky, D.; Taiuti, M.; Terreni, G.; Tézier, D.; Théraube, S.; Thompson, L. F.; Timmer, P.; Trasatti, L.; Trovato, A.; Tselengidou, M.; Tsirigotis, A.; Tzamarias, S.; Tzamariudaki, E.; Vallage, B.; Van Elewyck, V.; Vermeulen, J.; Vernin, P.; Vicini, P.; Viola, S.; Vivolo, D.; Werneke, P.; Wiggers, L.; Wilms, J.; de Wolf, E.; van Wooning, R. H. L.; Zonca, E.; Zornoza, J. D.; Zúñiga, J.; Zwart, A.

    2016-02-01

    A prototype detection unit of the KM3NeT deep-sea neutrino telescope has been installed at 3500m depth 80 km offshore the Italian coast. KM3NeT in its final configuration will contain several hundreds of detection units. Each detection unit is a mechanical structure anchored to the sea floor, held vertical by a submerged buoy and supporting optical modules for the detection of Cherenkov light emitted by charged secondary particles emerging from neutrino interactions. This prototype string implements three optical modules with 31 photomultiplier tubes each. These optical modules were developed by the KM3NeT Collaboration to enhance the detection capability of neutrino interactions. The prototype detection unit was operated since its deployment in May 2014 until its decommissioning in July 2015. Reconstruction of the particle trajectories from the data requires a nanosecond accuracy in the time calibration. A procedure for relative time calibration of the photomultiplier tubes contained in each optical module is described. This procedure is based on the measured coincidences produced in the sea by the ^{40}K background light and can easily be expanded to a detector with several thousands of optical modules. The time offsets between the different optical modules are obtained using LED nanobeacons mounted inside them. A set of data corresponding to 600 h of livetime was analysed. The results show good agreement with Monte Carlo simulations of the expected optical background and the signal from atmospheric muons. An almost background-free sample of muons was selected by filtering the time correlated signals on all the three optical modules. The zenith angle of the selected muons was reconstructed with a precision of about 3°.