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Sample records for gas cerenkov detector

  1. Monte Carlo simulation of gas Cerenkov detectors

    International Nuclear Information System (INIS)

    Mack, J.M.; Jain, M.; Jordan, T.M.

    1984-01-01

    Theoretical study of selected gamma-ray and electron diagnostic necessitates coupling Cerenkov radiation to electron/photon cascades. A Cerenkov production model and its incorporation into a general geometry Monte Carlo coupled electron/photon transport code is discussed. A special optical photon ray-trace is implemented using bulk optical properties assigned to each Monte Carlo zone. Good agreement exists between experimental and calculated Cerenkov data in the case of a carbon-dioxide gas Cerenkov detector experiment. Cerenkov production and threshold data are presented for a typical carbon-dioxide gas detector that converts a 16.7 MeV photon source to Cerenkov light, which is collected by optics and detected by a photomultiplier

  2. The design of the optical components and gas control systems of the CERN Omega Ring Imaging Cerenkov Detector

    International Nuclear Information System (INIS)

    Apsimon, R.J.; Cowell, J.; Flower, P.S.

    1985-06-01

    A large Ring Imaging Cerenkov Detector (RICH) has been commissioned for use at the CERN Omega Spectrometer. The general design of the device is discussed, and the dependence of the attainable spatial resolution and range of particle identification on its optical parameters is illustrated. The construction and performance of the major optical components and gas systems of the detector are also described. (author)

  3. Gas Cerenkov detector for measuring 16.7-MeV gamma rays from the D(T,γ)5He reaction

    International Nuclear Information System (INIS)

    Brolley, J.E.; Ladish, J.S.; Lyons, P.B.

    1983-01-01

    A gas Cerenkov detector has been developed for measuring radiation from the 16.7-MeV gamma branch of the D-T reaction. This has useful applications as a diagnostic tool for weapons tests at the Nevada Test Site (NTS), as well as for evaluation of ICF targets and Tokomak plasmas. The Cerenkov process was chosen because of excellent time response. A gas radiator allows threshold control to eliminate low-energy background, such as gamma radiation produced by a neutron capture or scattering. The detector consists of a thin aluminum converter to provide energetic pair and Compton electrons, a deflecting magnet, a Cerenkov radiator, and an optical system for collection and detection of Cerenkov light. The radiator is a gas chamber filled with approximately one atmosphere of carbon dioxide. A photodiode is used for light detection. The electron beam from the DOE/EG and G electron linear accelerator at EG and G's Santa Barbara Operations has been used to measure the detector response as functions of electron energy and gas pressure. A Monte Carlo production-transport code is used to calculate geometrical properties of the pair and Compton electron distributions as they enter the Cerenkov radiator. Fluorescence, transition radiation, and other optical backgrounds produced by subthreshold electrons are being evaluated in order to optimize the detector design

  4. Cerenkov ring imaging detector development at SLAC

    International Nuclear Information System (INIS)

    Williams, S.H.

    1984-06-01

    The imaging of Cerenkov light on to photosensitive detectors promises to be a powerful technique for identifying particles in colliding beam spectrometers. Toward this end two and three dimensional imaging photon detectors are being developed at SLAC. The present techniques involve photon conversion using easily ionized exotic chemicals like tetrakisdimethyl-amino-ethylene (TMAE) in a drift and amplifying gas mixture of methane and isobutane. Single photoelectrons from Cerenkov light are currently being drifted 20 cm and a new device under study will be used to study drifting up to 80 cm along a magnetic field. A short description of a large device currently being designed for the SLD spectrometer at the Stanford Linear Collider will be given

  5. The SLD Cerenkov Ring Imaging Detector: Progress report

    International Nuclear Information System (INIS)

    Ashford, V.; Bienz, T.; Bird, F.

    1986-10-01

    We describe test beam results from a prototype Cerenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider (SLC). The system includes both liquid and gas radiators, a long drift box containing gaseous TMAE and a proportional wire chamber with charge division readout. Measurements of the multiplicity and detection resolution of Cerenkov photons, from both radiators are presented. Various design aspects of a new engineering prototype, currently under construction, are discussed and recent R and D results relevant to this effort are reported

  6. Cerenkov radiation simulation in the Auger water ground detector

    International Nuclear Information System (INIS)

    Le Van Ngoc; Vo Van Thuan; Dang Quang Thieu

    2003-01-01

    The simulation of response of the Auger water Cerenkov ground detector to atmospheric shower muons in practically needed for the experimental research of cosmic rays at extreme energies. We consider here a simulation model for the process of emission and diffusion of Cerenkov photons concerned with muons moving through the detector volume with the velocity greater than the phase velocity of light in the water on purpose to define photons producing signal in the detector. (author)

  7. A Ring Imaging Cerenkov detector for the CERN OMEGA spectrometer

    International Nuclear Information System (INIS)

    Apsimon, R.J.; Cowell, J.; Flower, P.S.

    1984-12-01

    A large acceptance Ring Imaging Cerenkov detector has been constructed for use at the CERN Omega Spectrometer. The design of the detector is discussed, with attention paid to its principal components, and preliminary results are given which show that the detector is capable of identifying pions and protons at 100 GeV/c. (author)

  8. Photomultiplier tubes for Low Level Cerenkov Detectors

    International Nuclear Information System (INIS)

    Strindehag, O.

    1965-03-01

    Tube backgrounds of several 2-inch photomultiplier types having S11, 'S' , S13 and S20 cathodes are compared by measuring signal and background pulse height distributions at pulse heights corresponding to a few photo-electrons. The reference signal is generated by means of a β-source and a plexiglass radiator. It is found that comparatively good results are obtained with selected tubes of the EMI types 6097B and 9514B having equivalent dark current dc values down to 10 -12 input lumens. Special interest is devoted to the correlation between the measured tube backgrounds and the dark current dc values of the tubes, as a good correlation between these parameters simplifies the selection of photomultiplier tubes. The equivalent dark currents of the tested tubes extend over the range 10 -12 to 10 -9 input lumens. Although the investigation deals with photomultiplier tubes intended for use in low level Cerenkov detectors it is believed that the results could be valuable in other fields where photomultiplier tubes are utilized for the detection of weak light pulses

  9. Photomultiplier tubes for Low Level Cerenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Strindehag, O

    1965-03-15

    Tube backgrounds of several 2-inch photomultiplier types having S11, 'S' , S13 and S20 cathodes are compared by measuring signal and background pulse height distributions at pulse heights corresponding to a few photo-electrons. The reference signal is generated by means of a {beta}-source and a plexiglass radiator. It is found that comparatively good results are obtained with selected tubes of the EMI types 6097B and 9514B having equivalent dark current dc values down to 10{sup -12} input lumens. Special interest is devoted to the correlation between the measured tube backgrounds and the dark current dc values of the tubes, as a good correlation between these parameters simplifies the selection of photomultiplier tubes. The equivalent dark currents of the tested tubes extend over the range 10{sup -12} to 10{sup -9} input lumens. Although the investigation deals with photomultiplier tubes intended for use in low level Cerenkov detectors it is believed that the results could be valuable in other fields where photomultiplier tubes are utilized for the detection of weak light pulses.

  10. A ring image Cerenkov detector for the CERN Omega Spectrometer

    International Nuclear Information System (INIS)

    Davenport, M.; Deol, R.S.; Flower, P.S.

    1983-05-01

    A development program has been undertaken to produce a large ring image Cerenkov detector (RICH) for use at the CERN Omega Spectrometer. A prototype Cerenkov counter has been constructed and successfully operated in a high energy particle beam, Cerenkov rings having been observed in an experimental time projection chamber (TPC) using the photoionising agents Triethylamine (TEA) and Tetrakis (dimethylamine) ethylene (TMAE). Systematic measurements have been made of the optical properties of window materials and reflecting surfaces in the vacuum ultraviolet region. Results of these tests are presented, and the design of the large detector based on these experiences together with Monte Carlo simulations of the events expected in the WA69 experiment, is discussed. (author)

  11. The Omega Ring Imaging Cerenkov Detector readout system user's guide

    International Nuclear Information System (INIS)

    Hallewell, G.

    1984-11-01

    The manual describes the electronic readout system of the Ring Imaging Cerenkov Detector at the CERN Omega Spectrometer. The system is described in its configuration of September 1984 after the Rich readout system had been used in two Omega experiments. (U.K.)

  12. Cerenkov Detectors for Fission Product Monitoring in Reactor Coolant Water

    Energy Technology Data Exchange (ETDEWEB)

    Strindehag, O

    1967-09-15

    The expected properties of Cerenkov detectors when used for fission product monitoring in water cooled reactors and test loops are discussed from the point of view of the knowledge of the sensitivity of these detectors to some beta emitting isotopes. The basic theory for calculation of the detector response is presented, taking the optical transmission in the sample container and the properties of the photomultiplier tube into account. Special attention is paid to the energy resolution of this type of Cerenkov detector. For the design of practical detectors the results from several investigations of various window and reflector materials are given, and the selection of photomultiplier tubes is briefly discussed. In the case of optical reflectors and photomultiplier tubes reference is made to two previous reports by the author. The influence of the size and geometry of the sample container on the energy resolution follows from a separate investigation, as well as the relative merits of sample containers with transparent inner walls. Provided that the energy resolution of the Cerenkov detector is sufficiently high, there are several reasons for using this detector type for failed-fuel-element detection. It seems possible to attain the desired energy resolution by careful detector design.

  13. The Cerenkov ring-imaging detector recent progress and future development

    CERN Document Server

    Ekelöf, T J C; Tocqueville, J; Ypsilantis, Thomas

    1981-01-01

    Results are reported on measurements of Cerenkov ring images using a multistage MWPC with an argon-TEA gas mixture. A specific detector response of N/sub 0/=56 cm/sup -1/ was obtained. It is shown that with some minor modifications to the detector, this value can be raised to N/sub 0/=90 cm/sup -1/. Using an argon-methane-TEA mixture in the MWPC, it is shown that efficient single-photoelectron detection can be achieved with proportional wire amplification without preamplification. A design of a new type of drift chamber (TPC) detector for two-dimensional measurement of the ring image is described. The use of the Cerenkov ring-imaging technique in high- energy physics experimentation is discussed, and in particular a full solid-angle detector for LEP is suggested. (10 refs).

  14. The high pressure gas Cerenkov counter at the Omega Facility.

    CERN Multimedia

    1975-01-01

    The high-pressure gas Cerenkov was used to measure reactions as pion (or kaon)- hydrogen --> forward proton - X. It was built by the Ecole Polytechnique (Palaiseu). Here Peter Sonderegger and Patrick Fleury,

  15. Looking for anomalons with a segmented Cerenkov detector

    International Nuclear Information System (INIS)

    Olson, D.L.

    1984-10-01

    An experiment performed at the Lawrence Berkeley Laboratory Bevalac, Expt. 676H, to study the anomalon effect with a segmented total-internal-reflection Cerenkov detector is reported. Radiators of 3mm thick BK7W optical glass and 2mm thick fused silica and a beam of 40 Ca at 2.1 GeV/nucleon were used. Results are presented and discussed

  16. Development of CRID [Cerenkov Ring Imaging Detector] single electron wire detector

    International Nuclear Information System (INIS)

    Aston, D.; Bean, A.; Bienz, T.

    1989-02-01

    We describe the R and D effort to define the design parameters, method of construction and experimental results from the single electron wire detectors. These detectors will be used for particle identification using the Cerenkov Ring Imaging techniques in the SLD experiment at SLAC. We present measurements of pulse heights for several gases as a function of gas gain, charge division performance on a single electron signal using both 7 μm and 33 μm diameter carbon wires, photon feedback in TMAE laden gas, average pulse shape, and its comparison with the predicted shape and cross-talk. In addition, we present results of wire aging tests, and other tests associated with construction of this unusual type of wire chamber. 12 refs., 9 figs

  17. High gain multigap avalanche detectors for Cerenkov ring imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, R.S.; Lavender, W.M.; Leith, D.W.G.S.; Williams, S.H.

    1980-10-01

    We report on a continuing study of multigap parallel plate avalanche chambers, primarily as photoelectron detectors for use with Cerenkov ring imaging counters. By suitable control of the fields in successive gaps and by introducing screens to reduce photon feedback to the cathode the gain many be increased considerably. We have obtained gains in excess of 6 x 10/sup 7/ for photoelectrons with a good pulse height spectrum and expect to increase this further. We discuss the use of resistive anodes to give avalanche positions in two dimensions by charge division.

  18. Cerenkov detector for heavy-ion velocity measurements

    International Nuclear Information System (INIS)

    Olson, D.L.; Baumgartner, M.; Dufour, J.P.; Girard, J.G.; Greiner, D.E.; Lindstrom, P.J.; Symons, T.J.M.; Crawford, H.J.

    1984-08-01

    We have developed a highly sensitive velocity measuring detector using total-internal-reflection Cerenkov counters of a type mentioned by Jelly in 1958. If the velocity of the particle is above the threshold for total-internal-reflection these counters have a charge resolution of sigma = 0.18e for a 3mm thick glass radiator. For the velocity measurement we use a fused silica radiator so that the velocity of the particles are near the threshold for total-internal reflection. For momentum-analyzed projectile fragments of 1.6 GeV/nucleon 40 Ar, we have measured a mass resolution of sigma = 0.1u for isotope identification

  19. A large multi-cell threshold gas Cerenkov counter

    International Nuclear Information System (INIS)

    Declais, Y.; Aubert, J.J.; Bassompierre, G.; Payre, P.; Thenard, J.M.; Urban, L.

    1980-08-01

    A large multi-cell threshold gas Cerenkov counter consisting of 78 cells has been built for use in a high energy muon scattering experiment at CERN (European Muon Collaboration). It is used with neon, nitrogen or a mixture of those two gases, allowing the pion threshold to be varied between 6 and 20 GeV/c. The sensitive region of the counter has a length of 4.0 m and entrance and exit windows of 1.1 x 2.4 m 2 and 2.4 x 5.0 m 2 , respectively

  20. Optimization of an aerogel cerenkov detector having a mirror light collection system

    International Nuclear Information System (INIS)

    Johansson, K.E.; Aakesson, T.; Norrby, J.

    1979-01-01

    Cerenkov detectors with silica aerogel of refractive indec 1.03 as the radiator have been tested in a particle beam at the CERN Proton Synchrotron. With a detector surface of 22 x 50 cm 2 and 9 cm thickness of aerogel, the number of photoelectrons was found to be 6.5 for β = 1 particles. (author)

  1. A review of 4π Cerenkov ring imaging detectors

    International Nuclear Information System (INIS)

    Leith, D.W.G.S

    1989-06-01

    The design choices for 4π ring imaging Cerenkov counters -- both those of principle and those of practice -- are reviewed. The progress in construction and the performance of the devices being built for DELPHI and SLD are discussed. 13 refs., 22 figs

  2. JASA: A prototype water-Cerenkov air-shower detector

    International Nuclear Information System (INIS)

    Berley, D.; Dion, C.; Goodman, J.A.; Haines, T.J.; Kwok, P.W.; Stark, M.J.; Svoboda, R.C.; Ferguson, H.; Hoffman, C.M.; Horch, E.; Ellsworth, R.W.; Delay, R.S.; Lu, X.; Yodh, G.B.

    1991-01-01

    A small pilot experiment to examine the use of the water-Cerenkov technique for air shower detection was installed near the center of the CYGNUS air shower array. Preliminary results showing general agreement with simulations are presented. Thus, the technique promises to offer significant advances for VHE-UHE γ-ray astronomy

  3. Construction and testing of the SLD Cerenkov ring imaging detector

    International Nuclear Information System (INIS)

    Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Williams, D.A.; Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H.

    1990-01-01

    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

  4. Air core detectors for Cerenkov-free scintillation dosimetry of brachytherapy β-sources.

    Science.gov (United States)

    Eichmann, Marion; Thomann, Benedikt

    2017-09-01

    Plastic scintillation detectors are used for dosimetry in small radiation fields with high dose gradients, e.g., provided by β-emitting sources like 106 Ru/ 106 Rh eye plaques. A drawback is a background signal caused by Cerenkov radiation generated by electrons passing the optical fibers (light guides) of this dosimetry system. Common approaches to correct for the Cerenkov signal are influenced by uncertainties resulting from detector positioning and calibration procedures. A different approach to avoid any correction procedure is to suppress the Cerenkov signal by replacing the solid core optical fiber with an air core light guide, previously shown for external beam therapy. In this study, the air core concept is modified and applied to the requirements of dosimetry in brachytherapy, proving its usability for measuring water energy doses in small radiation fields. Three air core detectors with different air core lengths are constructed and their performance in dosimetry for brachytherapy β-sources is compared with a standard two-fiber system, which uses a second fiber for Cerenkov correction. The detector systems are calibrated with a 90 Sr/ 90 Y secondary standard and tested for their angular dependence as well as their performance in depth dose measurements of 106 Ru/ 106 Rh sources. The signal loss relative to the standard detector increases with increasing air core length to a maximum value of 58.3%. At the same time, however, the percentage amount of Cerenkov light in the total signal is reduced from at least 12.1% to a value below 1.1%. There is a linear correlation between induced dose and measured signal current. The air core detectors determine the dose rates for 106 Ru/ 106 Rh sources without any form of correction for the Cerenkov signal. The air core detectors show advantages over the standard two-fiber system especially when measuring in radiation fields with high dose gradients. They can be used as simple one-fiber systems and allow for an almost

  5. Lorentz angle studies for the SLD endcap Cerenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Coyle, P.; Cavalli-Sforza, M.; Coyne, D.

    1987-11-01

    The design of the endcap Cerenkov Ring Imaging Detectors for SLD requires a detailed understanding of how electrons drift in gases under the influence of crossed electric and magnetic fields. In this report, we present recent measurements of Lorentz angles and drift velocities in gases suitable for the endcap CRID photon detectors. We compare these measurements to predictions from a theoretical model; good agreement is observed. Based on our results we present a design for detectors operating in a 0.6 Tesla transverse magnetic field. 14 refs., 10 figs., 4 tabs

  6. Component and system tests of the SLD Cerenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S.; Dunwoodie, W.; Hallewell, G.; 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.; Va'vra, J.; Williams, S.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Williams, D.A.; Whitaker, J.S.; Wilson, R.J.; Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Witherell, M.; Yellin, S.; D'Oliveira, A.; Johnson, R.A.; Martinez, J.L.; Meadows, B.; Nussbaum, M.; Santha, A.K.S.; Shoup, A.; Stockdale, I.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H.

    1991-02-01

    The components of the SLD barrel Cerenkov Ring Imaging Detector (CRID) are now built and are being installed. We report on tests of these, including tests of the fiber optic calibration system, detailed studies of electron drift paths on production drift boxes and detectors, tests of the dynamic gating system and its effect on drift path distortions due to space-charge, and a measurement of the electron lifetime in a production drift box. In addition, we report on the UV transmission of recirculated liquid C 6 F 14 and on the effects of CRID construction materials on electron lifetime. 9 refs., 11 figs

  7. Component and system tests of the SLD Cerenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Bird, F.; Aston, D.; Dasu, S.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.; Nagamine, T.; Pavel, T.; Muller, D.; Williams, S.; Bienz, T.; Dolinsky, S.; Solodov, E.; Coyle, P.; Cavalli-Sforza, M.; Coyne, D.; Gagnon, P.; Liu, X.; Williams, D.A.

    1990-01-01

    The components of the SLD barrel Cerenkov Ring Imaging Detector (CRID) are now built and are being installed. This paper reports on tests of these components, including tests of the fiber optic calibration system, detailed studies of electron drift paths on production drift boxes and detectors, tests of the dynamic gating system and its effect on drift path distortions due to space-charge, and a measurement of the electron lifetime in a production drift box. In addition, the authors report on the UV transmission of recirculated liquid freon and on the effects of CRID construction materials on electron lifetime

  8. Component and system tests of the SLD Cerenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S.; Dunwoodie, W.; Hallewell, G.; 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.; Va'vra, J.; Williams, S.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Williams, D.A.; Whitaker, J.S.; Wilson, R.J.; Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Witherell, M.; Yellin, S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Meadows, B.; Nussbaum, M.; Santha, A.K.S.; Shoup, A.; Stockdale, I.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H.

    1990-10-01

    The components of the SLD barrel Cerenkov Ring Imaging Detector (CRID) are now built and are being installed. We report on tests of these components, including tests of the fiber optic calibration system, detailed studies of electron drift paths on production drift boxes and detectors, tests of the dynamic gating systems and its effect on drift path distortions due to space-charge, and a measurement of the electron lifetime in a production drift box. In addition, we report on the UV transmission of recirculated liquid freon and on the effects of CRID construction materials on electron lifetime. 16 refs., 12 figs

  9. Recent operational performance of the CERN Omega Ring Imaging Cerenkov Detector

    International Nuclear Information System (INIS)

    Apsimon, R.J.; Flower, P.S.; Freeston, K.A.

    1985-10-01

    We discuss the design and construction of the Time Projection chambers (TPCs) of the Omega Ring Imaging Cerenkov Detector (RICH). Details are given of the TPC high voltage system and its monitoring and control. In addition, the operation and monitoring of the readout is described together with results of tests on the performance of the front end amplifiers. The operation of the RICH TPCs and electronics during the first data run of WA69, in 1984, is discussed together with relevant results from laboratory tests. Results from the preliminary analysis of a sample of data from the 1984 run are also presented

  10. A method for unique identification of relativistic /greater than 0.5/ magnetic monopoles with a fast film Cerenkov detector

    Science.gov (United States)

    Pinsky, L. S.; Hagstrom, R.

    1975-01-01

    A magnetic monopole traversing a dielectric medium at a velocity greater than the phase velocity of light in that medium, will give rise to Cerenkov radiation with the electric field tangent to the cone generated by the photon wave propagation vector, and the magnetic field normal to that surface. This is the opposite polarization to that encountered with an electric charge. It is proposed that either by inserting a linearly polarizing layer between the radiator and the photographic emulsion, or by selecting a linearly polarizing material as the radiator, one could directly observe the field polarization by examining the photographic image and thus uniquely identify a magnetic monopole. The ability of the detector is further enhanced by the index of refraction dependence of the Cerenkov output from a magnetic monopole.

  11. Gas filled detectors

    International Nuclear Information System (INIS)

    Stephan, C.

    1993-01-01

    The main types of gas filled nuclear detectors: ionization chambers, proportional counters, parallel-plate avalanche counters (PPAC) and microstrip detectors are described. New devices are shown. A description of the processes involved in such detectors is also given. (K.A.) 123 refs.; 25 figs.; 3 tabs

  12. Cerenkov-ΔE-Cerenkov detector for high-energy cosmic-ray isotopes and an accelerator study of 40Ar and 56Fe fragmentation

    International Nuclear Information System (INIS)

    Lau, K.H.

    1985-01-01

    This thesis has two major parts. The first part of the thesis will describe a high energy cosmic ray detector - the High Energy Isotope Spectrometer Telescope (HEIST). HEIST is a large area (0.25 m 2 sr) balloon-borne isotope spectrometer designed to make high-resolution measurements of isotopes in the element range from neon to nickel (10 less than or equal to Z less than or equal to 28) at energies of about 2 GeV/nucleon. The instrument consists of a stack of 12 NaI(Tl) scintillators, two Cerenkov counters, and two plastic scintillators. The second part of this thesis presents an experimental measurement of the isotopic composition of the fragments from the breakup of high energy 40 Ar and 56 Fe nuclei. Cosmic ray composition studies rely heavily on semi-empirical estimates of the cross-sections for the nuclear fragmentation reactions which alter the composition during propagation through the interstellar medium. Experimentally measured yields of isotopes from the fragmentation of 40 Ar and 56 Fe are compared with calculated yields based on semi-empirical cross-section formulae

  13. Hydrogen gas detector

    International Nuclear Information System (INIS)

    Bohl, T.L.

    1982-01-01

    A differential thermocouple hydrogen gas detector has one thermocouple junction coated with an activated palladium or palladium-silver alloy catalytic material to allow heated hydrogen gas to react with the catalyst and raise the temperature of that junction. The other juction is covered with inert glass or epoxy resin, and does not experience a rise in temperature in the presence of hydrogen gas. A coil heater may be mounted around the thermocouple junctions to heat the hydrogen, or the gas may be passed through a heated block prior to exposing it to the thermocouples

  14. The technique of Cerenkov ring image detection

    International Nuclear Information System (INIS)

    Langerveld, D.

    1990-01-01

    Charged particles with an energy between 2 GeV and 25 GeV can be identified in the DELPHI barrel RICH detector by using the technique of Cerenkov ring image detection. The method of identification is based on a determination of the Cerenkov angle by measuring the positions of the emitted Cerenkov photons to high precision in a photon detector. The resolution in the photon that can be obtained depends mainly on the chromatic dispersion in the radiators and on the resolution in the photon detector is used in the barrel RICH in combination with two radiators. The photon detector consists of 48 drift tubes, constructed from quarz plates, each equipped with a wire chamber at the end. The drift gas with which the tubes are filled contains a small admixture of TMAE vapour from which the Cerenkov photons can liberate photoelectrons. It is shown in this thesis that an efficient photon detection and an accurate localization of the photon conversion points is possible. The spatial resolution of the photon detector is determind by the resolution of the wire chambe, the accuracy of the drift measurement, the distortions in the paths of the drifting electrons. The resolution of the wire chamber has been measured to be 0.8 mm in the x- and 1.7 mm in the y-coordinate. The error in the z-coordinate introduced by the drift time measurement is 0.2 mm. The distortions in the paths of the drifting electrons have been measured both in the x and y-direction. The longitudinal and transverse diffusion coefficients have been measured as a function of the field strength for two different drift gas mixtures. (author). 96 refs.; 61 figs.; 11 tabs

  15. Cerenkov imaging.

    Science.gov (United States)

    Das, Sudeep; Thorek, Daniel L J; Grimm, Jan

    2014-01-01

    Cerenkov luminescence (CL) has been used recently in a plethora of medical applications like imaging and therapy with clinically relevant medical isotopes. The range of medical isotopes used is fairly large and expanding. The generation of in vivo light is useful since it circumvents depth limitations for excitation light. Cerenkov luminescence imaging (CLI) is much cheaper in terms of infrastructure than positron emission tomography (PET) and is particularly useful for imaging of superficial structures. Imaging can basically be done using a sensitive camera optimized for low-light conditions, and it has a better resolution than any other nuclear imaging modality. CLI has been shown to effectively diagnose disease with regularly used PET isotope ((18)F-FDG) in clinical setting. Cerenkov luminescence tomography, Cerenkov luminescence endoscopy, and intraoperative Cerenkov imaging have also been explored with positive conclusions expanding the current range of applications. Cerenkov has also been used to improve PET imaging resolution since the source of both is the radioisotope being used. Smart imaging agents have been designed based on modulation of the Cerenkov signal using small molecules and nanoparticles giving better insight of the tumor biology. © 2014 Elsevier Inc. All rights reserved.

  16. Cerenkov Imaging

    OpenAIRE

    Das, Sudeep; Thorek, Daniel L.J.; Grimm, Jan

    2014-01-01

    Cerenkov luminescence (CL) has been used recently in a plethora of medical applications like imaging and therapy with clinically relevant medical isotopes. The range of medical isotopes used is fairly large and expanding. The generation of in vivo light is useful since it circumvents depth limitations for excitation light. Cerenkov luminescence imaging (CLI) is much cheaper in terms of infrastructure than positron emission tomography (PET) and is particularly useful for imaging of superficial...

  17. Gas pixel detectors

    International Nuclear Information System (INIS)

    Bellazzini, R.; Baldini, L.; Brez, A.; Cavalca, F.; Latronico, L.; Massai, M.M.; Minuti, M.; Omodei, N.; Pesce-Rollins, M.; Sgro, C.; Spandre, G.; Costa, E.; Soffitta, P.

    2007-01-01

    With the Gas Pixel Detector (GPD), the class of micro-pattern gas detectors has reached a complete integration between the gas amplification structure and the read-out electronics. To obtain this goal, three generations of application-specific integrated circuit of increased complexity and improved functionality has been designed and fabricated in deep sub-micron CMOS technology. This implementation has allowed manufacturing a monolithic device, which realizes, at the same time, the pixelized charge-collecting electrode and the amplifying, shaping and charge measuring front-end electronics of a GPD. A big step forward in terms of size and performances has been obtained in the last version of the 0.18 μm CMOS analog chip, where over a large active area of 15x15 mm 2 a very high channel density (470 pixels/mm 2 ) has been reached. On the top metal layer of the chip, 105,600 hexagonal pixels at 50 μm pitch have been patterned. The chip has customable self-trigger capability and includes a signal pre-processing function for the automatic localization of the event coordinates. In this way, by limiting the output signal to only those pixels belonging to the region of interest, it is possible to reduce significantly the read-out time and data volume. In-depth tests performed on a GPD built up by coupling this device to a fine pitch (50 μm) gas electron multiplier are reported. Matching of the gas amplification and read-out pitch has let to obtain optimal results. A possible application of this detector for X-ray polarimetry of astronomical sources is discussed

  18. Detector module for gas monitor

    International Nuclear Information System (INIS)

    1980-01-01

    The invention relates to radioactive source detector module for use in a gas monitor. It is adapted to contain the source and other detector components to allow sealed coupling of those components with other portions of the gas monitor. It is particularly concerned with the use of radioactive materials used as electron sources in gas monitors. The module is used to detect changes in electron flow caused by partial absorption of the electron capture gas flowing between two electrodes. The assembly includes a gas flow source, a gas receiver and an electronic assembly for receiving a signal from the detector. The radioactive source and electrodes are housed so that they are connected to the gas flow source so as to prevent accidental or undesired disconnection. It is designed so that the detector module may be removed or replaced into the gas monitor assemblies by untrained personnel so as to prevent exposure to the radioactive material. Full details are given. (U.K.)

  19. Radon gas detector

    International Nuclear Information System (INIS)

    Madnick, P.A.; Sherwood, R.W.

    1990-01-01

    This patent describes a radon gas detector. It comprises: a housing having an interior chamber, the interior chamber being completely closed to ambient light, the interior chamber being divided into an environment connecting chamber and a radiation ascertaining chamber; radiation sensitive means mounted between the environment connecting chamber and the radiation ascertaining chamber; air movement means mounted in connection with the environment connecting chamber. The air movement means for moving ambient air through the environment connecting chamber; electronic means for detecting radiation within the air which is passing through the environment connecting chamber. The electronic means also including radiation counting means. The electronic means producing an output based on the type and quantity of radiation in the environment connecting chamber; and display electronics for receiving the output and displaying accordingly a display representative of the amount and type of radiation located within the environment connecting chamber and hence within the ambient air

  20. Review of recent progress in the development of Cerenkov Ring Imaging Detectors

    International Nuclear Information System (INIS)

    Leith, D.W.G.S.

    1985-11-01

    The principle behind the Cherenkov Ring Imaging Detectors (CRIDs) involves focussing the Cherenkov light, emitted by a relativistic charged particle in passing through a radiator medium, onto a high efficiency photocathode which can be in turn read out with good spatial resolution, to localize the point of origin of the photoelectrons. This information permits the reconstruction of the circle of Cherenkov light for each particle above threshold, and hence the determination of the Cherenkov angle to an accuracy of a few percent. The groups currently working on these detectors are discussed, the status of these projects is examined, and progress is reported on the R and D on two 4-pi devices being prepared for physics at the Z 0 . The activities are being done at Fermilab, CERN, and SLAC. 8 refs., 32 figs

  1. Noble Gas Detectors

    CERN Document Server

    Aprile, Elena; Bolozdynya, Alexander I; Doke, Tadayoshi

    2006-01-01

    This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc.The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentation

  2. Gas chromatography: mass selective detector

    International Nuclear Information System (INIS)

    Lapinskas, R.

    1988-01-01

    The mechanism of mass spectrometry technique directed for detecting molecular structures is described, with some considerations about its operational features. This mass spectrometer is used as a gas chromatography detector. (author)

  3. Signal generation in gas detectors

    International Nuclear Information System (INIS)

    Stillman, A.

    1993-01-01

    This tutorial describes the generation of electrical signals in gas detectors. Ionization of the gas by the passage of charged particles generates these signals. Starting with the Bethe-Bloch equation, the treatment is a general introduction to the production of ion-pairs in gas devices. I continue with the characterization of the ionization as an electrical signal, and calculate the signal current in a simple example. Another example demonstrates the effect of space charge on the design of a detector. The AGS Booster ionization profile monitor is a model for this calculation

  4. Cerenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Ashford, V.; Etkin, A.; Honma, A.; Kostoulas, I.; Lanou, R.; Watts, T.

    1978-01-01

    Particle mass identification capability will be very important for much of the physics at ISABELLE. It will be required for studying quantum number flow in quark--quark scattering (jet and high P/sub t/ physics), hadronic decays of W's and Z's, and ''onium'' states. It will be essential for detecting and studying ''naked flavor'' states and generally required or at least very useful for most hadronic physics at ISABELLE. The large all-purpose detectors envisioned for ISABELLE require particle identification covering up to 4π solid angle with high multiplicity capability, high rate capability, insensitivity to high magnetic fields, and large dynamic range (1 to 400 GeV/c). In addition, it would be desirable to have this information for on-line event selection. At present there are only four practical methods for doing charged hadron identification: time-of-flight, dE/dX (ionization sampling), transition radiation, and Cerenkov radiation. All these methods need independent momentum determination and are effective over only limited kinematic ranges. Although the status and foreseeable development of these techniques are discussed at length elsewhere their expected capabilities are summarized in order to compare them with Cerenkov techniques. For the sake of argument a 4π steradian detector with an inner radius of 2 m is assumed

  5. A proposal for a precision test of the standard model by neutrino-electron scattering (Large /hacek C/erenkov Detector Project)

    International Nuclear Information System (INIS)

    Allen, R.C.; Lu, X-Q.; Gollwitzer, K.

    1988-04-01

    A precision measurement of neutrino-electron elastic scattering from a beam stop neutrino source at LAMPF is proposed. The total error in sin 2 θ/sub W/ is estimated to be +-0.89/percent/. The experiment also will be sensitive to neutrino oscillations and supernova-neutrino bursts, and should set improved limits on the neutrino-charge radius and magnetic-dipole moment. The detector consists of a 2.5-million-gallon tank of water with approximately 14,000 photomultiplier tubes lining the surfaces of the tank. Neutrino-electron scattering events will be observed from the /hacek C/erenkov radiation emitted by the electrons in the water. 19 refs

  6. A proposal for a precision test of the standard model by neutrino-electron scattering (Large /hacek C/erenkov Detector Project)

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.C.; Lu, X-Q.; Gollwitzer, K.; Igo, G.J.; Gulmez, E.; Whitten, C.; VanDalen, G.; Layter, J.; Fung, Sun Yui; Shen, B.C.

    1988-04-01

    A precision measurement of neutrino-electron elastic scattering from a beam stop neutrino source at LAMPF is proposed. The total error in sin/sup 2/theta/sub W/ is estimated to be +-0.89/percent/. The experiment also will be sensitive to neutrino oscillations and supernova-neutrino bursts, and should set improved limits on the neutrino-charge radius and magnetic-dipole moment. The detector consists of a 2.5-million-gallon tank of water with approximately 14,000 photomultiplier tubes lining the surfaces of the tank. Neutrino-electron scattering events will be observed from the /hacek C/erenkov radiation emitted by the electrons in the water. 19 refs.

  7. The micro slit gas detector

    Energy Technology Data Exchange (ETDEWEB)

    Claude Labbe, J.; Gomez, F. E-mail: fgomez@cern.ch; Nunez, T.; Pazos, A.; Vazquez, P

    1999-06-01

    We describe the first tests with a new proportional gas detector. Its geometry consists of slits opened in a copper metallized kapton foil with 30 {mu}m anode strips suspended in these openings. In this way, the multiplication process is similar to a standard MSGC. The fundamental difference is the absence of an insulating substrate around the anode. Also the material budget is significantly reduced, and the problems related to charging-up or polarization are removed. Ageing properties of this detector are under study.

  8. The micro slit gas detector

    International Nuclear Information System (INIS)

    Claude Labbe, J.; Gomez, F.; Nunez, T.; Pazos, A.; Vazquez, P.

    1999-01-01

    We describe the first tests with a new proportional gas detector. Its geometry consists of slits opened in a copper metallized kapton foil with 30 μm anode strips suspended in these openings. In this way, the multiplication process is similar to a standard MSGC. The fundamental difference is the absence of an insulating substrate around the anode. Also the material budget is significantly reduced, and the problems related to charging-up or polarization are removed. Ageing properties of this detector are under study

  9. Aerogel Cerenkov counters at DESY

    International Nuclear Information System (INIS)

    Poelz, G.

    1984-11-01

    In high energy physics it is common to identify a charged particle and its kinematical parameters by the measurement of its momentum and its velocity. Cerenkov detectors have developed into a standard tool because they operate in the γ = (1-β 2 )sup(-1/2) range from about 1 to 100 which is not easily accessible by other devices. Pions, kaons and protons in present high energy experiments reach energies of several GeV. Threshold Cerenkov detectors for these particles need indices of refraction below 1.1 which are often produced with gases under high pressure. The design for chambers operating in this region was drasticly simplified when porous materials serving as Cerenkov radiators were invented. These chambers complement the time-of-flight counters, which cover the low energy region. Aerogel of silica is up to now the only porous substance with sufficient optical transparency. Its quality has been improved substantially in recent times so that large size detectors can be constructed. (orig.)

  10. Daya Bay Antineutrino Detector Gas System

    OpenAIRE

    Band, H. R.; Cherwinka, J. J.; Chu, M-C.; Heeger, K. M.; Kwok, M. W.; Shih, K.; Wise, T.; Xiao, Q.

    2012-01-01

    The Daya Bay Antineutrino Detector gas system is designed to protect the liquid scintillator targets of the antineutrino detectors against degradation and contamination from exposure to ambient laboratory air. The gas system is also used to monitor the leak tightness of the antineutrino detector assembly. The cover gas system constantly flushes the gas volumes above the liquid scintillator with dry nitrogen to minimize oxidation of the scintillator over the five year lifetime of the experimen...

  11. Proportional gas scintillation detectors and their applications

    International Nuclear Information System (INIS)

    Petr, I.

    1978-01-01

    The principle is described of a gas proportional scintillation detector and its function. Dependence of Si(Li) and xenon proportional detectors energy resolution on the input window size is given. A typical design is shown of a xenon detector used for X-ray spetrometry at an energy of 277 eV to 5.898 keV and at a gas pressure of 98 to 270 kPa. Gas proportional scintillation detectors show considerable better energy resolution than common proportional counters and even better resolution than semiconductor Si(Li) detectors for low X radiation energies. For detection areas smaller than 25 mm 2 Si(Li) detectors show better resolution, especially for higher X radiation energies. For window areas 25 to 190 mm 2 both types of detectors are equal, for a window area exceeding 190 mm 2 the proportional scintillation detector has higher energy resolution. (B.S.)

  12. Gas position sensitive x-ray detectors

    International Nuclear Information System (INIS)

    Barbosa, A.F.

    1994-12-01

    The construction of gas x-ray detectors used to count and localize x-ray photons in one and two dimensions is reported. The principles of operation of the detectors are described, as well as the electronic modules comprised in the data acquisition system. Results obtained with detectors built at CBPF are shown, illustrating the performance of the Linear Position Sensitive Detectors. (author). 6 refs, 14 figs

  13. Cerenkov counter for the experiment NA3

    CERN Multimedia

    1978-01-01

    The program of the NA3 experiment included the study of hadronic interactions with a large transverse momentum pT, thus the inclusion in the set-up of three gas threshold Cerenkov counters of large acceptance. The photo shows the downstream part of the second Cerenkov (located at the output of the magnet). The yellow membrane is a temporary protection for the optics (shown in photo 7810540X) to be taken away when fixing this part to the gas tank (entering the magnet and not shown). The photomultipliers all around are heavily shielded.

  14. Daya Bay Antineutrino Detector gas system

    Science.gov (United States)

    Band, H. R.; Cherwinka, J. J.; Chu, M.-C.; Heeger, K. M.; Kwok, M. W.; Shih, K.; Wise, T.; Xiao, Q.

    2012-11-01

    The Daya Bay Antineutrino Detector gas system is designed to protect the liquid scintillator targets of the antineutrino detectors against degradation and contamination from exposure to ambient laboratory air. The gas system is also used to monitor the leak tightness of the antineutrino detector assembly. The cover gas system constantly flushes the gas volumes above the liquid scintillator with dry nitrogen to minimize oxidation of the scintillator over the five year lifetime of the experiment. This constant flush also prevents the infiltration of radon or other contaminants into these detecting liquids keeping the internal backgrounds low. Since the Daya Bay antineutrino detectors are immersed in the large water pools of the muon veto system, other gas volumes are needed to protect vital detector cables or gas lines. These volumes are also purged with dry gas. Return gas is monitored for oxygen content and humidity to provide early warning of potentially damaging leaks. The design and performance of the Daya Bay Antineutrino Detector gas system is described.

  15. Cerenkov counters at the Omega Facility

    CERN Multimedia

    1975-01-01

    P. Petroff on the left. Here one sees both the gas Cerenkov counters sitting in front of the magnet to select forward emitted particles. The smaller one, working at high pressure, sits nearest to the Omega magnet (see photo 7505073X), the other (see photo 7505071X) works at atmospheric pressure.

  16. Progress in micro-pattern gas detectors

    International Nuclear Information System (INIS)

    Bellazzini, Ronaldo

    2001-01-01

    Micro-Pattern Gas Detectors are position-sensitive proportional counters whose sense electrodes are constructed using micro-electronics , thin-film or advanced PCB techniques.The feature size attainable using these methods is of the order of a few microns and the detectors demonstrate excellent spatial resolution and fast charge collection. I will review recent progress on Micro patterned Gas Detectors for tracking and other cross-disciplinary applications.I will focus on the design principles,performance capability and limitations. A short list of interesting applications will be discussed

  17. Development of a PET/Cerenkov-light hybrid imaging system

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Hamamura, Fuka; Kato, Katsuhiko; Ogata, Yoshimune; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Hatazawa, Jun; Watabe, Hiroshi

    2014-01-01

    Purpose: Cerenkov-light imaging is a new molecular imaging technology that detects visible photons from high-speed electrons using a high sensitivity optical camera. However, the merit of Cerenkov-light imaging remains unclear. If a PET/Cerenkov-light hybrid imaging system were developed, the merit of Cerenkov-light imaging would be clarified by directly comparing these two imaging modalities. Methods: The authors developed and tested a PET/Cerenkov-light hybrid imaging system that consists of a dual-head PET system, a reflection mirror located above the subject, and a high sensitivity charge coupled device (CCD) camera. The authors installed these systems inside a black box for imaging the Cerenkov-light. The dual-head PET system employed a 1.2 × 1.2 × 10 mm 3 GSO arranged in a 33 × 33 matrix that was optically coupled to a position sensitive photomultiplier tube to form a GSO block detector. The authors arranged two GSO block detectors 10 cm apart and positioned the subject between them. The Cerenkov-light above the subject is reflected by the mirror and changes its direction to the side of the PET system and is imaged by the high sensitivity CCD camera. Results: The dual-head PET system had a spatial resolution of ∼1.2 mm FWHM and sensitivity of ∼0.31% at the center of the FOV. The Cerenkov-light imaging system's spatial resolution was ∼275μm for a 22 Na point source. Using the combined PET/Cerenkov-light hybrid imaging system, the authors successfully obtained fused images from simultaneously acquired images. The image distributions are sometimes different due to the light transmission and absorption in the body of the subject in the Cerenkov-light images. In simultaneous imaging of rat, the authors found that 18 F-FDG accumulation was observed mainly in the Harderian gland on the PET image, while the distribution of Cerenkov-light was observed in the eyes. Conclusions: The authors conclude that their developed PET/Cerenkov-light hybrid imaging

  18. Radon chamber for soil gas detectors

    International Nuclear Information System (INIS)

    Andersson, P.

    1987-01-01

    Swedish Geological Co (SGAB) has designed and constructed a chamber for the calibration of detectors and instruments intended for the measurement of radon-222 in soil gas. In the chamber radon detectors may be exposed in a model environment which simulates ground conditions with respect to radon concentration, temperature and humidity. Also included in the research project is the development of methods for calibration procedures, together with test measurements. In general, these measurements indicate that the radon detectors tested are sufficiently accurate and reliable for radon measurements in Swedish soils if they are calibrated in an environment which simulates ground conditions. (orig./HP)

  19. Field tests and commercialization of natural gas leak detectors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, D S; Jeon, J S; Kim, K D; Cho, Y A [R and D Center, Korea Gas Corporation, Ansan (Korea)

    1999-09-01

    Objectives - (1) fields test of industrial gas leak detection monitoring system. (2) commericialization of residential gas leak detector. Contents - (1) five sets of gas leak detection monitoring system were installed at natural gas transmition facilities and tested long term stability and their performance. (2) improved residential gas leak detector was commercialised. Expected benefits and application fields - (1) contribution to the improvement of domestic gas sensor technology. (2) localization of fabrication technology for gas leak detectors. 23 refs., 126 figs., 37 tabs.

  20. Gas detectors: recent developments and future perspectives

    International Nuclear Information System (INIS)

    Sauli, F.

    1998-01-01

    Thirty years after the invention of the multi-wire proportional chamber, and 20 from the first Vienna Wire Chamber Conference, the interest and research efforts devoted to gas detectors are still conspicuous, as demonstrated by the number of papers submitted to this conference. Innovative and performing devices have been perfected over the years, used in experiments, and still developed today. Introduced 10 years ago, the micro-strip gas chamber appears to fulfill the needs of high-luminosity trackers; progress in this field will be reported, followed by a discussion on discharge problems encountered and possible solutions. Recent and potentially more powerfull devices such as the micro-gap, narrow-gap and micro-dot chambers will be described. A new generation of detectors exploiting avalanche multiplication in narrow gaps has emerged recently, namely micromegas, CAT (compteur a trous) and the Gas Electron Multiplier (GEM); whilst still in their infancy, they have promising performances with increased reliability in harsh operating conditions. I will describe also some 'tools of trade' used to model the counting action and to analyze the properties of the detectors, discuss limitations to their performances, and suggest ways to improvement. Several still controversial subjects of study (as for example, aging), and imaginative efforts of the experimenters ensure a continuing progress in the field of gas detectors, and new editions of this conference for years to come. (author)

  1. Preliminary results on tests of a Cerenkov ring imaging device employing a photoionizing PWC

    Energy Technology Data Exchange (ETDEWEB)

    Durkin, S.; Honma, A.; Leith, D.W.G.S.

    1978-08-01

    A brief description of techniques and problems of ring imaging Cerenkov detectors employing photoionizing PWC's is discussed. Preliminary results on a one dimensional ring imaging device tested at SLAC in May and June of 1978 are then presented. These results include rough measurements of the Cerenkov ring in nitrogen, argon, neon, and helium produced by a collimated positron beam.

  2. Switching a gas detector types misromegas

    International Nuclear Information System (INIS)

    Hafsi, Marwa; Gannouni, Sonia

    2010-01-01

    Micromegas is a gas enclosure made up of two stages separated by a micro grille: the first volume of gas, 2 cm is limited by cathode and the micro grille, is the space of conversion or of drift where are creating the primary electron-ion pairs. The second volume, 100 μ m limited by the micro grille and the plan of conduction (anode), is the space of amplification which with the function to amplify the electrons by phenomenon d' avalanche. The function of this type of detector rests on various physical parameters which come into play: speed of drift of the electrons in gas, space and temporal resolution, attachment The simulations allow studying these parameters to optimize the operation of the detector by choosing a good compromise, in particular with regard to the composition of gas. Two simulation programs used to understand certain physical phenomena (configuration of the field electric in the detector, properties of transport of the electrons in gas) are Garfield and Magboltz.

  3. Developing and evaluating new micropattern gas detectors

    International Nuclear Information System (INIS)

    Villa, Marco

    2014-02-01

    Micropattern gas detectors (MPGDs) were introduced in the late 1980s in order to overcome the limited rate capability of traditional proportional counters. Thanks to their microscopic electrode structures, MPGDs are faster and more precise than the previous gas detectors and soon gained popularity. Two of the most successful MPGDs are the gas electron multiplier (GEM) and the micro-mesh gaseous structure (Micromegas). In this thesis I present the features of GEMs and Micromegas, some of their current applications and the research and development that I have done on these technologies. My activity covered two main topics: the test and enhancement of single-mask GEMs for large-area applications and the study of spark-tolerant Micromegas for the upgrade of the ATLAS Small Wheels.

  4. Cerenkov fiber sampling calorimeters

    International Nuclear Information System (INIS)

    Arrington, K.; Kefford, D.; Kennedy, J.; Pisani, R.; Sanzeni, C.; Segall, K.; Wall, D.; Winn, D.R.; Carey, R.; Dye, S.; Miller, J.; Sulak, L.; Worstell, W.; Efremenko, Y.; Kamyshkov, Y.; Savin, A.; Shmakov, K.; Tarkovsky, E.

    1994-01-01

    Clear optical fibers were used as a Cerenkov sampling media in Pb (electromagnetic) and Cu (hadron) absorbers in spaghetti calorimeters, for high rate and high radiation dose experiments, such as the forward region of high energy colliders. The fiber axes were aligned close to the direction of the incident particles (1 degree--7 degree). The 7 λ deep hadron tower contained 2.8% by volume 1.5 mm diameter core clear plastic fibers. The 27 radiation length deep electromagnetic towers had packing fractions of 6.8% and 7.2% of 1 mm diameter core quartz fibers as the active Cerenkov sampling medium. The energy resolution on electrons and pions, energy response, pulse shapes and angular studies are presented

  5. Improved gas mixtures for gas-filled particle detectors

    Science.gov (United States)

    Christophorou, L.G.; McCorkle, D.L.; Maxey, D.V.; Carter, J.G.

    Improved binary and tertiary gas mixture for gas-filled particle detectors are provided. The components are chosen on the basis of the principle that the first component is one gas or mixture of two gases having a large electron scattering cross section at energies of about 0.5 eV and higher, and the second component is a gas (Ar) having a very small cross section at and below about 0.5 eV; whereby fast electrons in the gaseous mixture are slowed into the energy range of about 0.5 eV where the cross section for the mixture is small and hence the electron mean free path is large. The reduction in both the cross section and the electron energy results in an increase in the drift velocity of the electrons in the gas mixtures over that for the separate components for a range of E/P (pressure-reduced electron field) values. Several gas mixtures are provided that provide faster response in gas-filled detectors for convenient E/P ranges as compared with conventional gas mixtures.

  6. Cerenkov radiation from cosmic rays

    International Nuclear Information System (INIS)

    Turver, K.E.

    1988-01-01

    It is almost 40 years since it was suggested that Cerenkov radiations may be produced in the atmosphere by the passage of the cosmic radiation and account for a small part of the night sky brightness. The first detection of this visible Cerenkov radiation followed within a few years and by the 1960s the atmospheric Cerenkov radiation technique was established as a tool in high energy astrophysics. An exciting new field of astronomy, high energy gamma ray astronomy, has developed which relies on the atmospheric Cerenkov light. We here review the mechanism for the production of Cerenkov light in the atmosphere and summarize the contributions to high energy astrophysics made using the technique. (author)

  7. Gas microstrip detectors on resistive plastic substrates

    International Nuclear Information System (INIS)

    Dixit, M.S.; Oakham, F.G.; Armitage, J.C.

    1993-01-01

    Plastics are desirable as substrates for gas microstrip detectors (GMDs) because of their flexibility, low density and long radiation length. GMDs have been fabricated on white Tedlar which has bulk electrical conductivity and ion-implanted Upilex which has a thin electrically conductive layer on the surface of an insulator. The effect of back plane voltage on the gain of such GMDs is investigated. Three 200 μm pitch, ion-implanted Upilex GMDs were recently tested in a high intensity beam at CERN. The anode signals were read out using fast, low noise, high gain amplifiers. Preliminary results of the test are presented

  8. Performance of gas electron multiplier (GEM) detector

    International Nuclear Information System (INIS)

    Han, S. H.; Moon, B. S.; Kim, Y. K.; Chung, C. E.; Kang, H. D.; Cho, H. S.

    2002-01-01

    We have investigated in detail the operating properties of Gas Electron Multiplier (GEM) detectors with a double conical and a cylindrical structure in a wide range of external fields and GEM voltages. With the double conical GEM, the gain gradually increased with time by 10%; whereas this surface charging was eliminated with the cylindrical GEM. Effective gains above 1000 were easily observed over a wide range of collection field strengths in a gas mixture of Ar/CO 2 (70/30). The transparency and electron collection efficiency were found to depend on the ratio of external field and the applied GEM voltage; the mutual influence of both drift and collection fields was found to be trivial

  9. Silica aerogel Cerenkov counter

    International Nuclear Information System (INIS)

    Yasumi, S.; Masaike, A.; Yamamoto, A.; Yoshimura, Y.; Kawai, H.

    1984-03-01

    In order to obtain silica aerogel radiators of good quality, the prescription used by Saclay group has been developed. We have done several experiments using beams from KEK.PS to test the performance of a Cerenkov counter with aerogel modules produced in KEK. It turned out that these modules had excellent quality. The production rate of silica aerogel in KEK is 15 -- 20 litres a week. Silica aerogel modules of 20 x 10 x 3 cm 3 having the refractive index of 1.058 are successfully being used by Kyoto University group in the KEK experiment E92 (Σ). Methodes to produce silica aerogel with higher refractive index than 1.06 has been investigated both by heating an module with the refractive index of 1.06 and by hydrolyzing tetraethyl silicate. (author)

  10. Express method and radon gas measurement detector

    International Nuclear Information System (INIS)

    Khajdarov, R.A.; Khajdarov, R.R.

    2004-01-01

    The purpose of this work was to improve the activated charcoal adsorption method. The detector consisted of an electronic unit (200 mm x 180 mm x 80 mm) and a scintillation cell (a tube 200 mm long, 60 mm diam.). The electronic unit contained a power supply, amplifier, discriminator, timer, counter and indicator. The scintillation cell contained a zinc sulfide scintillator, photomultiplier, preamplifier, high voltage power supply and a 200 ml chamber above the scintillator. This chamber was intended to situate activated carbon fibrous absorber and air compressor. In this method, air is drawn through a filter to remove radon decay products and then through the activated carbon cloth by using a compressor. Sampling takes between 5 and 15 minutes. After the sampling, the cloth is heated for 5-10 sec up to 200-250 deg C by electric current passing through the fiber. Radon gas evaporates from the cloth and the device detects scintillation pulses. Owing to a high radon preconcentration factor (by adsorption of radon on the activated carbon cloth from 50-150 L of air of and evaporation into the small volume of the chamber), the detection limit of the method is 2-4 Bq/m 3 . Since the distance between the filter, cloth and scintillator is over 80 mm, the detector only measures radiation from radon without interference from the radon decay products, remaining in the filter and cloth

  11. Multi-angle gas and Si detector particle telescope

    International Nuclear Information System (INIS)

    McDonald, R.J.; Sobotka, L.G.; Wozniak, G.J.

    1984-01-01

    A simple gas ΔE and multiple Si E detector telescope (called a WEDGE detector) has been constructed, which is particularly suitable for angular distribution studies of light ion emission from fragments following heavy ion reactions. This inexpensive detector was designed to have a low detection threshold, large dynamic range and constant ΔE path length. The detector has been used in studies of complex fragment emission (typically 2 < Z < 10) following compound nucleus and deep-inelastic heavy ion reactions

  12. Pressure regulation system for modern gas-filled detectors

    International Nuclear Information System (INIS)

    McDonald, R.J.

    1986-08-01

    A gas pressure and flow regulation system has been designed and constructed to service a wide variety of gas-filled detectors which operate at pressures of ∼2 to 1000 Torr and flow rate of ∼5 to 200 standard cubic centimeters per minute (sccm). Pressure regulation is done at the detector input by a pressure transducer linked to a solenoid leak valve via an electronic control system. Gas flow is controlled via a mechanical leak valve at the detector output. Interchangeable transducers, flowmeters, and leak valves allow for different pressure and flow ranges. The differential pressure transducer and control system provide automatic let-up of vacuum chambers to atmospheric pressure while maintaining a controlled overpressure in the detector. The gas system is constructed on a standard 19'' rack-mounted panel from commercially available parts. Five of these systems have been built and are routinely used for both ionization chambers and position-sensitive avalanche detectors

  13. Gas-discharge particle detector with ball-tipped anodes

    International Nuclear Information System (INIS)

    Travkin, V.I.; Khazins, D.M.

    1987-01-01

    A new gas-discharge particle detector, whose anode is a set of balls 2mm in diameter is investigated. The chamber is blowing down by the argon-methane-methylal gas mixture with the ratio 3:1:1. The detector operates in the self-quenching streamer mode, has high efficiency and a wide counting characteristic plateau. The maximum counting rate of particles at one ball is ∼ 2.5x10 4 s -1 . The ball-tipped anodes allow making reliable complex-shaped detectors. Two-coordinate detection of multiparticle events can be naturally organized in detectors like that

  14. The Track Imaging Cerenkov Experiment

    Science.gov (United States)

    Wissel, S. A.; Byrum, K.; Cunningham, J. D.; Drake, G.; Hays, E.; Horan, D.; Kieda, D.; Kovacs, E.; Macgill, S.; Nodulman, L.; hide

    2012-01-01

    We describe a dedicated cosmic-ray telescope that explores a new method for detecting Cerenkov radiation from high-energy primary cosmic rays and the large particle air shower they induce upon entering the atmosphere. Using a camera comprising 16 multi-anode photomultiplier tubes for a total of 256 pixels, the Track Imaging Cerenkov Experiment (TrICE) resolves substructures in particle air showers with 0.086deg resolution. Cerenkov radiation is imaged using a novel two-part optical system in which a Fresnel lens provides a wide-field optical trigger and a mirror system collects delayed light with four times the magnification. TrICE records well-resolved cosmic-ray air showers at rates ranging between 0.01-0.1 Hz.

  15. Development of low noise preamplifier for the detection and position determination of single electrons in a Cerenkov Ring Imaging Detector by charge division

    International Nuclear Information System (INIS)

    Spencer, E.; Coyle, P.; Williams, D

    1987-10-01

    A preamplifier having 500 electrons noise (rms) has been developed for the detection and location of single electrons in a CRID detector at the SLD. A single channel contains preamp, RC-CR shaper, gain adjustment, driver, and calibration circuitry. Noise and linearity measurements are presented

  16. A portable gas recirculation unit for gaseous detectors

    Science.gov (United States)

    Guida, R.; Mandelli, B.

    2017-10-01

    The use of greenhouse gases (usually C2H2F4, CF4 and SF6) is sometimes necessary to achieve the required performance for some gaseous detectors. The consumption of these gases in the LHC systems is reduced by recycling the gas mixture thanks to a complex gas recirculation system. Beyond greenhouse gas consumption due to LHC systems, a considerable contribution is generated by setups used for LHC detector upgrade projects, R&D activities, detector quality assurance or longevity tests. In order to minimise this emission, a new flexible and portable gas recirculation unit has been developed. Thanks to its low price, flexibility and user-friendly operation it can be easily adapted for the different types of detector systems and set-ups.

  17. Detector for recoil nuclei stopping in the spark chamber gas

    International Nuclear Information System (INIS)

    Aleksanyan, A.S.; Asatiani, T.L.; Ivanov, V.I.; Mkrtchyan, G.G.; Pikhtelev, R.N.

    1974-01-01

    A detector consisting of the combination of a drift and a wide gap spark chambers and designed to detect recoil nuclei stopping in the spark chamber gas is described. It is shown, that by using an appropriate discrimination the detector allows to detect reliably the recoil nuclei in the presence of intensive electron and γ-quanta beams

  18. A gas pixel detector for X-ray imaging

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.

    1991-11-01

    A simple, robust form of gas pixel detector is discussed which is based on the use of electronic connector pins as the gain elements. With a rate capability of >10 5 counts/s per pin, an X-ray imaging detector system capable of counting at global rates of the order of 10 10 counts/s is foreseen. (author)

  19. Preparation of silica aerogel for Cerenkov counters

    International Nuclear Information System (INIS)

    Poelz, G.; Riethmueller, R.

    1981-09-01

    Aerogel of silica was produced with an index of refraction of n = 1.024 to equip the TASSO Cerenkov detector with 1700 litres of this radiator medium. In the production process, which is described in detail, different parameters were varied to determine their influence on the shape and the optical quality of the aerogel samples. With the present equipment samples with a size of 17 x 17 x 2.3 cm 3 were manufactured at a rate of 144 pieces per week. A production efficiency of about 90% was obtained. The index of refraction for all samples around n = 1.024 is distributed with sigmasub(n) = 1.3 x 10 -3 . They have an optical transmission length of Λ = 2.64 cm at a wavelength lambda = 438 nm with sigmasub(Λ) = 0.22 cm. For samples with n = 1.017, Λ is found to be about 30% higher. (orig.) [de

  20. Gas microstrip detectors based on flexible printed circuit

    International Nuclear Information System (INIS)

    Salomon, M.; Crowe, K.; Faszer, W.; Lindsay, P.; Curran Maier, J.M.

    1995-09-01

    Microstrip Gas Detectors (MSGC's) were introduced some years ago as position sensitive detectors capable of operating at very high rates. The authors have studied the properties of a new type of Gas Microstrip Counter built using flexible printed circuit technology. They describe the manufacturing procedures, the assembly of the device, as well as its operation under a variety of conditions, gases and types of radiation. They also describe two new passivation materials, tantalum and niobium, which produce effective surfaces

  1. Development of Micro-Pattern Gas Detectors Technologies

    CERN Multimedia

    Richer, J; Barsuk, S; Shah, M K; Catanesi, M G; Colaleo, A; Maggi, M; Loddo, F; Berardi, V; Bagliesi, M; Menon, G; Richter, R; Lahonde-hamdoun, C; Dris, M; Chechik, R; Ochi, A; Hartjes, F; Lopes, I M; Deshpande, A; Franz, A; Fiutowski, T A; Ferreira, A; Bastos de oliveira, C A; Miller, B W; Monrabal-capilla, F; Liubarsky, I; Plazas de pinzon, M C; Tsarfati, T; Voss, B J R; Carmona martinez, J M; Stocchi, A; Dinu, N; Semeniouk, I; Giebels, B; Marton, K; De leo, R; De lucia, E; Alviggi, M; Bellerive, A; Herten, L G; Zimmermann, S U; Giomataris, I; Peyaud, A; Schune, P; Delagnes, E; Delbart, A; Charles, G; Wang, W; Markou, A; Arazi, L; Cibinetto, G; Edo, Y; Neves, F F; Solovov, V; Stoll, S; Sampsonidis, D; Dabrowski, W; Mindur, B; Sauli, F; Calapez de albuquerque veloso, J F; Kahlaoui, N; Sharma, A; Zenker, K; Cebrian guajardo, S V; Luzon marco, G M; Guillaudin, O J H; Cornebise, P; Lounis, A; Bruel, P J; Laszlo, A; Mukerjee, K; Nappi, E; Nuzzo, S V; Bencivenni, G; Tessarotto, F; Levorato, S; Dixit, M S; Riallot, M; Jeanneau, F; Nizery, F G; Maltezos, S; Kyriakis, A; Lyashenko, A; Van der graaf, H; Ferreira marques, R; Alexa, C; Liyanage, N; Dehmelt, K; Hemmick, T K; Polychronakos, V; Cisbani, E; Garibaldi, F; Koperny, S Z; Das neves dias carramate, L F; Munoz-vidal, J; Gutierrez, R; Van stenis, M; Resnati, F; Lupberger, M; Desch, K K; Chefdeville, M; Vouters, G; Ranieri, A; Lami, S; Shekhtman, L; Dolgov, A; Bamberger, A; Landgraf, U; Kortner, O; Ferrero, A; Aune, S; Attie, D M; Bakas, G; Balossino, I; Tsigaridas, S; Surrow, B; Gnanvo, K A K; Feege, N M; Woody, C L; Bhattacharya, S; Capogni, M; Veenhof, R J; Tapan, I; Dangendorf, V; Monteiro bernades, C M; Castro serrato, H F; De oliveira, R; Ropelewski, L; Behnke, T; Boudry, V; Radicioni, E; Lai, A; Shemyakina, E; Giganon, A E; Titov, M; Papakrivopoulos, I; Komai, H; Van bakel, N A; Tchepel, V; Repond, J O; Li, Y; Kourkoumelis, C; Tzamarias, S; Majumdar, N; Kowalski, T; Da rocha azevedo, C D; Serra diaz cano, L; Alvarez puerta, V; Trabelsi, A; Riegler, W; Ketzer, B F; Rosemann, C G; Herrera munoz, D C; Drancourt, C; Mayet, F; Geerebaert, Y; De robertis, G; Felici, G; Scribano memoria, A; Cecchi, R; Dalla torre, S; Gregori, M; Buzulutskov, A; Schwegler, P; Sanchez nieto, F J; Colas, P M A; Gros, M; Neyret, D; Zito, M; Ferrer ribas, E; Breskin, A; Martoiu, V S; Purschke, M L; Loomba, D; Gasik, P J; Petridou, C; Kordas, K; Mukhopadhyay, S; Bucciantonio, M; Biagi, S F; Ji, X; Kanaki, K; Zavazieva, D; Capeans garrido, M D M; Schindler, H; Kaminski, J; Krautscheid, T; Lippmann, C; Arora, R; Dafni, T; Garcia irastorza, I; Puill, V; Wicek, F B; Burmistrov, L; Singh, K P; Kroha, H; Kunne, F; Alexopoulos, T; Daskalakis, G; Geralis, T; Bettoni, D; Heijhoff, K; Xiao, Z; Tzanakos, G; Leisos, A; Frullani, S; Sahin, O; Kalkan, Y; Giboni, K; Krieger, C; Breton, D R; Bhattacharyya, S; Abbrescia, M; Erriquez, O; Paticchio, V; Cardini, A; Aloisio, A; Turini, N; Bressan, A; Tikhonov, Y; Schumacher, M; Simon, F R; Nowak, S; Herlant, S; Chaus, A; Fanourakis, G; Bressler, S; Homma, Y; Timmermans, J; Fonte, P; Underwood, D G; Azmoun, B; Fassouliotis, D; Wiacek, P; Dos santos covita, D; Monteiro da silva, A L; Yahlali haddou, N; Marques ferreira dos santos, J; Domingues amaro, F

    The proposed R&D collaboration, RD51, aims at facilitating the development of advanced gas-avalanche detector technologies and associated electronic-readout systems, for applications in basic and applied research. Advances in particle physics have always been enabled by parallel advances in radiation-detector technology. Radiation detection and imaging with gas-avalanche detectors, capable of economically covering large detection volumes with a low material budget, have been playing an important role in many fields. Besides their widespread use in particle-physics and nuclear-physics experiments, gaseous detectors are employed in many other fields: astro-particle research and applications such as medical imaging, material science, and security inspection. While extensively employed at the LHC, RHIC, and other advanced HEP experiments, present gaseous detectors (wire-chambers, drift-tubes, resistive-plate chambers and others) have limitations which may prevent their use in future experiments. Present tec...

  2. Intercomparison of radon gas detectors 1999 and 2000 at PSI

    International Nuclear Information System (INIS)

    Schuler, Christoph; Butterweck, Gernot

    2000-10-01

    This report describes the results of two radon intercomparison exercises performed by the Reference Laboratory for Radon Gas Activity Concentration Measurements at Paul Scherrer Institut from Sep 9th to Oct 6th, 1999, and from March 21st to 28th, 2000. Radon gas detectors and instruments were exposed in the PSI Radon Chamber in reference atmospheres to 1060 kBqhm -3 radon gas exposure at an average radon gas concentration of 6400 Bqm -3 and to 2050 kBqhm -3 radon gas exposure at an average radon gas concentration of 12500 Bqm -3 , respectively. These intercomparison exercises determined the performance of electret ionisation chambers, track etch detectors and measuring instruments at high humidity (1999 Intercomparison Exercise) and at a high radon gas exposure (2000 Intercomparison Exercise). In the 1999 Intercomparison Exercise, electret ionisation chambers revealed an influence on high humidity. This effect may be due to impurities on a microscopic scale on the electrets of these detectors. With few exceptions, in both the 1999 and the 2000 Radon Intercomparison Exercise the deviations of the measurement results to the reference radon gas concentration values were less than 15% (traceability criterion) and the standard deviation of the results of five detectors less than 15% (reproducibility criterion). (author) [de

  3. Intercomparison of radon gas detectors 1997 at PSI

    International Nuclear Information System (INIS)

    Schuler, Christoph; Butterweck-Dempewolf, Gernot

    1998-05-01

    Between Nov 14 and Nov 20, 1997, the Reference Laboratory for Radon Gas Activity Concentration Measurements at Paul Scherrer Institut performed the 1997 Radon Intercomparison Exercise. Radon gas detectors and instruments were exposed in the PSI Radon Chamber during seven days in a reference atmosphere with an average radon gas concentration of 3860 Bqm -3 . The majority of the participants at this intercomparison were Swiss Radon Gas Measurement Laboratories acknowledged by the Swiss Federal Office for Health. Criteria for this acknowledgement are a deviation of the measurement results to the reference value below 15% (traceability criterion) and a standard deviation of the mean of five detector measurement results below 15% (reproducibility criterion). With the exception of three participants, the results of electret ionisation chambers, track etch detectors and measuring instruments fulfilled the demanded traceability and reproducibility criteria. (author)

  4. Substrate-induced instability in gas microstrip detectors

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.

    1992-12-01

    The results of a programme of research into substrate-induced gain instability in gas microstrip detectors are reported. Information has been collected on a wide range of substrates including many commonly available glasses and ceramics. A theoretical model of the gain instability is proposed. While we have not yet found an acceptable substrate for the construction of high flux detectors our experience points to electronically conductive glasses as the most promising source of a stable substrate. (Author)

  5. Developments in gas detectors for synchrotron x-ray radiation

    International Nuclear Information System (INIS)

    Fischer, J.; Radeka, V.; Smith, G.C.

    1985-09-01

    New results on the physical limitations to position resolution in gas detectors for x-rays (approx. =3 to 20 keV) due to the range of photoelectrons and Auger electrons are discussed. These results were obtained with a small gap detector in which position readout was accomplished by using a very low noise centroid finding technique. A description is given of position sensitive detectors for medium rates (a few x 10 5 photons per second), using delay line readout, and for very high rates (approx. =10 8 photons per second), using fast signal shaping on the output of each anode wire

  6. Solubility investigations in support of ultrasensitive noble gas detector development

    International Nuclear Information System (INIS)

    Gross, K.C.; Andersen, A.; Russ, W.R.; Stuenkel, D.; Valentine, J.D.

    1998-01-01

    Argonne National Laboratory (ANL) and the University of Cincinnati (UC) have been developing a new class of ultrasensitive noble gas detectors that are based upon the ANL discovery that corn oil has a high affinity for heavy noble gas absorption at room temperature but releases the noble gases with warming or by other low-energy-input means. Environmental applications for this new class of fluid-based detectors include ultrahigh sensitivity radioxenon detectors for comprehensive test ban treaty surveillance, improved fission gas detectors for enhanced environmental surveillance in the vicinity of US Department of Energy, US Department of Defense, and US Nuclear Regulatory Commission licensed facilities, and improved integrating Rn detectors for earthquake prediction. They present the results of theoretical and experimental investigations into the solubility phenomena of heavy noble gases (Rn, Xe, and Kr) in triglyceride oils. They intend for the findings presented herein to be used to guide future selection, development, and refinement of vegetable and other hydrocarbon oils to bring further enhancements to noble gas detection efficiencies

  7. Solubility investigations in support of ultrasensitive noble gas detector development

    International Nuclear Information System (INIS)

    Gross, K. C.

    1998-01-01

    Argonne National Laboratory (ANL) and the University of Cincinnati (UC) have been developing a new class of ultrasensitive noble gas detectors that are based upon the ANL discovery that corn oil has a high affinity for heavy noble gas absorption at room temperature, but releases the noble gases with warming or by other low-energy-input means. Environmental applications for this new class of fluid-based detectors include ultrahigh sensitivity radioxenon detectors for Comprehensive Test Ban Treaty Surveillance, improved fission gas detectors for enhanced environmental surveillance in the vicinity of DOE, DOD, and NRC-licensed facilities, and improved integrating Rn detectors for earthquake prediction. The purpose of the present paper is to present the results of theoretical and experimental investigations into the solubility phenomena of heavy noble gases (Rn, Xe, and Kr) in triglyceride oils. It is the authors' intention that the findings presented herein may be used to guide future selection, development, and refinement of vegetable and other hydrocarbon oils to bring further enhancements to noble gas detection efficiencies

  8. Gas Pixel Detectors for low energy X-ray polarimetry

    International Nuclear Information System (INIS)

    Spandre, Gloria

    2007-01-01

    Gas Pixel Detectors are position-sensitive proportional counters in which a complete integration between the gas amplification structure and the read-out electronics has been reached. Various generation of Application-Specific Integrated Circuit (ASIC) have been designed in deep submicron CMOS technology to realize a monolithic device which is at the same time the charge collecting electrode and the analog amplifying and charge measuring front-end electronics. The experimental response of a detector with 22060 pixels at 80 μm pitch to polarized and un-polarized X-ray radiation is shown and the application of this device for Astronomical X-ray Polarimetry discussed

  9. Gas microstrip detectors for X-ray tomographic flow imaging

    CERN Document Server

    Key, M J; Luggar, R D; Kundu, A

    2003-01-01

    A investigation into the suitability of gas microstrip detector technology for a high-speed industrial X-ray tomography system is reported. X-ray energies in the region 20-30 keV are well suited to the application, which involves imaging two-dimensional slices through gas/liquid multiphase pipeline flows for quantitative component fraction measurement. Stable operation over a period representing several hundred individual tomographic scans at gas gains of 500 is demonstrated using a Penning gas mixture of krypton/propylene.

  10. Micro controller based system for characterizing gas detector operating parameters

    International Nuclear Information System (INIS)

    Thakur, Vaishali M.; Verma, Amit K.; Anilkumar, S.; Babu, D.A.R.; Sharma, D.N.; Harikumar, M.

    2011-01-01

    The estimation and analysis of radioactivity levels in samples from environment and from various stages of nuclear fuel cycle operations has become a matter of concern for the implementation of radiological safety procedures. Gas filled/ flow detectors play crucial role in achieving this objective. Since these detectors need high voltage for their operation, the operating characteristics of each detector for optimum performance has to be determined before incorporating into the systems. The operating voltages of these detectors are ranging from few hundred volts to few kilo volts. Present paper describes the design of microcontroller based system to control two HV modules (Electron tubes make: PS2001/12P) independently and acquire data from different gas filled radiation detectors simultaneously. The system uses Philips 80C552 microcontroller based Single Board Computer (SBC). The inbuilt DAC and ADC of microcontroller were used to control HV from 0-2000 with less than ± 1 %, error 1000V. The starting HV, HV step size, decision making intelligence to terminate HV increment (for preset plateau slope) and data acquisition (for preset time), data acquisition time etc., can be programmed. Nearly 200 detectors data (20 data points per detector) can be stored and transferred to PC on request. Data collected by the system for LND 719 GM detectors with starting voltage from 500 V, HV step size of 24 V and 100 seconds counting time to find out the plateau length. The plateau slope and length obtained with this system for LND 719 GM detectors are 3-5%/100V and ∼ 150V respectively. (author)

  11. Electrocatalytic cermet gas detector/sensor

    Science.gov (United States)

    Vogt, Michael C.; Shoemarker, Erika L.; Fraioli, deceased, Anthony V.

    1995-01-01

    An electrocatalytic device for sensing gases. The gas sensing device includes a substrate layer, a reference electrode disposed on the substrate layer comprised of a nonstoichiometric chemical compound enabling oxygen diffusion therethrough, a lower reference electrode coupled to the reference electrode, a solid electrolyte coupled to the lower reference electrode and an upper catalytically active electrode coupled to the solid electrolyte.

  12. A scintillation detector for measuring inert gas beta rays

    International Nuclear Information System (INIS)

    Shi Hengchang; Yu Yunchang

    1989-10-01

    The inert gas beta ray scintillation detector, which is made of organic high polymers as the base and coated with compact fluorescence materials, is a lower energy scintillation detector. It can be used in the nuclear power plant and radioactive fields as a lower energy monitor to detect inert gas beta rays. Under the conditions of time constant 10 minutes, confidence level is 99.7% (3σ), the intensity of gamma rays 2.6 x 10 -7 C/kg ( 60 Co), and the minimum detectable concentration (MDC) of this detector for 133 Xe 1.2 Bq/L. The measuring range for 133 Xe is 11.1 ∼ 3.7 x 10 4 Bq/L. After a special measure is taken, the device is able to withstand 3 x 10 5 Pa gauge pressure. In the loss-of-cooolant-accident, it can prevent the radioactive gas of the detector from leaking. This detector is easier to be manufactured and decontaminated

  13. Inverse Cerenkov experiment

    International Nuclear Information System (INIS)

    Kimura, W.D.

    1993-01-01

    The final report describes work performed to investigate inverse Cherenkov acceleration (ICA) as a promising method for laser particle acceleration. In particular, an improved configuration of ICA is being tested in a experiment presently underway on the Accelerator Test Facility (ATF). In the experiment, the high peak power (∼ 10 GW) linearly polarized ATF CO 2 laser beam is converted to a radially polarized beam. This is beam is focused with an axicon at the Cherenkov angle onto the ATF 50-MeV e-beam inside a hydrogen gas cell, where the gas acts as the phase matching medium of the interaction. An energy gain of ∼12 MeV is predicted assuming a delivered laser peak power of 5 GW. The experiment is divided into two phases. The Phase I experiments, which were completed in the spring of 1992, were conducted before the ATF e-beam was available and involved several successful tests of the optical systems. Phase II experiments are with the e-beam and laser beam, and are still in progress. The ATF demonstrated delivery of the e-beam to the experiment in Dec. 1992. A preliminary ''debugging'' run with the e-beam and laser beam occurred in May 1993. This revealed the need for some experimental modifications, which have been implemented. The second run is tentatively scheduled for October or November 1993. In parallel to the experimental efforts has been ongoing theoretical work to support the experiment and investigate improvement and/or offshoots. One exciting offshoot has been theoretical work showing that free-space laser acceleration of electrons is possible using a radially-polarized, axicon-focused laser beam, but without any phase-matching gas. The Monte Carlo code used to model the ICA process has been upgraded and expanded to handle different types of laser beam input profiles

  14. Development of multiwire gas detectors for X-rays

    International Nuclear Information System (INIS)

    Sales, Eraldo de

    2015-01-01

    This work presents the prototype of a 2D position sensitive gas detector for application in X-ray scattering and diffraction experiments. Starting from a detector initially developed for other applications and will show the required changes on the original concept of this device. The strategy used to determine the necessary adaptations were based on searching in the literature for the overall characteristics of a multi-wire X-ray detector (choice of gas, pressure, window, etc.), the use of simulations, implementation of the changes and finally operational tests. Computational tools were used to calculate the mechanical strength and attenuation of the X-ray photons that helped to determine the most appropriate material for the construction of the entrance window. Detector simulations were built with Garfield software and were used to study the overall properties of the detector, and to determine the optimum parameters for the equipment operation. Typical parameters are the distance between the wires, wire diameter, high voltage to be used, among several other parameters. The results obtained showed that the multi-wire detector concept with the implemented adaptations allowed the detection of X-rays. However, depending on the application, it may be necessary improve the resolution of the equipment, in order to have a better description of the collected data. Several ideas are suggested for this improvement. It is also presented interesting results obtained with a microscopic pattern detector called triple GEM. This device belongs to the Gas Detectors Development group (GDD group) at CERN and was used in my training at this institution. The results showed the potential of the equipment for detection of X-rays. The results and simulations presented in this work, confirmed that the changes in the concept of the original detector permitted it use on X-ray detection applications. Also, it was possible to obtain several indications for further optimization, which may

  15. FGLD A novel and compact micro-pattern gas detector

    CERN Document Server

    Dick, Louis; Watts, David

    2004-01-01

    A new gas detector which combines in the same structure the gas amplification mechanism and the position sensitive readout, named the field gradient lattice detector (FGLD), is being developed at CERN. The detector, reminiscent in geometry of a multi-wire proportional chamber but with a different field configuration can be fabricated as two or more layers of micro-patterned parallel tracks on a variety of substrate materials. Two preliminary proof-of-concept designs without position sensitivity have been fabricated as copper tracks of 50 mum width and 150 mum pitch on polyimide in a 3D geometry and on epoxy in a 2D geometry. They have been shown to detect the 5.9 keV X-rays of an $^{55}Fe$ source with a stable gain ranging from 500 to 5000 in a 3 mm drift chamber containing an argon carbon-dioxide gas mixture. The elegance and compactness of the FGLD design make it a very attractive gas detector solution both economically and mechanically. Most interestingly, the 3D FGLD design on flexible polyimide should gr...

  16. Radiology utilizing a gas multiwire detector with resolution enhancement

    Science.gov (United States)

    Majewski, Stanislaw; Majewski, Lucasz A.

    1999-09-28

    This invention relates to a process and apparatus for obtaining filmless, radiological, digital images utilizing a gas multiwire detector. Resolution is enhanced through projection geometry. This invention further relates to imaging systems for X-ray examination of patients or objects, and is particularly suited for mammography.

  17. CASAGEM: a readout ASIC for micro pattern gas detectors

    International Nuclear Information System (INIS)

    He Li; Deng Zhi; Liu Yinong

    2012-01-01

    A readout ASIC for micro pattern gas detectors has been designed This ASIC integrates 16 channels for anode readout and 1 channel for cathode readout which can make use of the signal of detector's cathode to generate a trigger Every channel can provide amplification and shaping of detector signals. The ASIC can also provide adjustable gain which can be adjusted from 2 mV/fC to 40 mV/fC, and adjustable shaping time which can be adjusted from 20 ns to 80 ns; so this ASIC can be applied to detectors with wide range output signal and different counting rate. The ASIC is fabricated with Chartered 0.35 μm CMOS process More circuit design Details and test results will be presented. (authors)

  18. A risk-based approach to flammable gas detector spacing.

    Science.gov (United States)

    Defriend, Stephen; Dejmek, Mark; Porter, Leisa; Deshotels, Bob; Natvig, Bernt

    2008-11-15

    Flammable gas detectors allow an operating company to address leaks before they become serious, by automatically alarming and by initiating isolation and safe venting. Without effective gas detection, there is very limited defense against a flammable gas leak developing into a fire or explosion that could cause loss of life or escalate to cascading failures of nearby vessels, piping, and equipment. While it is commonly recognized that some gas detectors are needed in a process plant containing flammable gas or volatile liquids, there is usually a question of how many are needed. The areas that need protection can be determined by dispersion modeling from potential leak sites. Within the areas that must be protected, the spacing of detectors (or alternatively, number of detectors) should be based on risk. Detector design can be characterized by spacing criteria, which is convenient for design - or alternatively by number of detectors, which is convenient for cost reporting. The factors that influence the risk are site-specific, including process conditions, chemical composition, number of potential leak sites, piping design standards, arrangement of plant equipment and structures, design of isolation and depressurization systems, and frequency of detector testing. Site-specific factors such as those just mentioned affect the size of flammable gas cloud that must be detected (within a specified probability) by the gas detection system. A probability of detection must be specified that gives a design with a tolerable risk of fires and explosions. To determine the optimum spacing of detectors, it is important to consider the probability that a detector will fail at some time and be inoperative until replaced or repaired. A cost-effective approach is based on the combined risk from a representative selection of leakage scenarios, rather than a worst-case evaluation. This means that probability and severity of leak consequences must be evaluated together. In marine and

  19. Development of multiwire gas detectors for X-rays; Desenvolvimento de detectores a gas multifilares para raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Sales, Eraldo de

    2015-06-01

    This work presents the prototype of a 2D position sensitive gas detector for application in X-ray scattering and diffraction experiments. Starting from a detector initially developed for other applications and will show the required changes on the original concept of this device. The strategy used to determine the necessary adaptations were based on searching in the literature for the overall characteristics of a multi-wire X-ray detector (choice of gas, pressure, window, etc.), the use of simulations, implementation of the changes and finally operational tests. Computational tools were used to calculate the mechanical strength and attenuation of the X-ray photons that helped to determine the most appropriate material for the construction of the entrance window. Detector simulations were built with Garfield software and were used to study the overall properties of the detector, and to determine the optimum parameters for the equipment operation. Typical parameters are the distance between the wires, wire diameter, high voltage to be used, among several other parameters. The results obtained showed that the multi-wire detector concept with the implemented adaptations allowed the detection of X-rays. However, depending on the application, it may be necessary improve the resolution of the equipment, in order to have a better description of the collected data. Several ideas are suggested for this improvement. It is also presented interesting results obtained with a microscopic pattern detector called triple GEM. This device belongs to the Gas Detectors Development group (GDD group) at CERN and was used in my training at this institution. The results showed the potential of the equipment for detection of X-rays. The results and simulations presented in this work, confirmed that the changes in the concept of the original detector permitted it use on X-ray detection applications. Also, it was possible to obtain several indications for further optimization, which may

  20. The GRANDE detector

    International Nuclear Information System (INIS)

    Adams, A.; Bond, R.; Coleman, L.; Rollefson, A.; Wold, D.; Bratton, C.B.; Gurr, H.; Kropp, W.; Nelson, M.; Price, L.R.; Reines, F.; Schultz, J.; Sobel, H.; Svoboda, R.; Yodh, G.; Burnett, T.; Chaloupka, V.; Wilkes, R.J.; Cherry, M.; Ellison, S.B.; Guzik, T.G.; Wefel, J.; Gaidos, J.; Loeffler, F.; Sembroski, G.; Wilson, C.; Goodman, J.; Haines, T.J.; Kielczewska, D.; Lane, C.; Steinberg, R.; Lieber, M.; Nagle, D.; Potter, M.; Tripp, R.

    1990-01-01

    In this paper we present a detector facility which meets the requirements outlined above for a next-generation instrument. GRANDE (Gamma Ray and Neutrino DEtector) is an imaging, water Cerenkov detector, which combines in one facility an extensive air shower array and a high-energy neutrino detector. (orig.)

  1. Gas detectors for x-ray lasers

    International Nuclear Information System (INIS)

    Tiedtke, K.; Feldhaus, J.; Hahn, U.; Jastrow, U.; Nunez, T.; Tschentscher, T.; Bobashev, S. V.; Sorokin, A. A.; Hastings, J. B.; Moeller, S.; Cibik, L.; Gottwald, A.; Hoehl, A.; Kroth, U.; Krumrey, M.; Schoeppe, H.; Ulm, G.; Richter, M.

    2008-01-01

    We have developed different types of photodetectors that are based on the photoionization of a gas at a low target density. The almost transparent devices were optimized and tested for online photon diagnostics at current and future x-ray free-electron laser facilities on a shot-to-shot basis with a temporal resolution of better than 100 ns. Characterization and calibration measurements were performed in the laboratory of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY II in Berlin. As a result, measurement uncertainties of better than 10% for the photon-pulse energy and below 20 μm for the photon-beam position were achieved at the Free-electron LASer in Hamburg (FLASH). An upgrade for the detection of hard x-rays was tested at the Sub-Picosecond Photon Source in Stanford

  2. Gas detectors for x-ray lasers

    Science.gov (United States)

    Tiedtke, K.; Feldhaus, J.; Hahn, U.; Jastrow, U.; Nunez, T.; Tschentscher, T.; Bobashev, S. V.; Sorokin, A. A.; Hastings, J. B.; Möller, S.; Cibik, L.; Gottwald, A.; Hoehl, A.; Kroth, U.; Krumrey, M.; Schöppe, H.; Ulm, G.; Richter, M.

    2008-05-01

    We have developed different types of photodetectors that are based on the photoionization of a gas at a low target density. The almost transparent devices were optimized and tested for online photon diagnostics at current and future x-ray free-electron laser facilities on a shot-to-shot basis with a temporal resolution of better than 100 ns. Characterization and calibration measurements were performed in the laboratory of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY II in Berlin. As a result, measurement uncertainties of better than 10% for the photon-pulse energy and below 20 μm for the photon-beam position were achieved at the Free-electron LASer in Hamburg (FLASH). An upgrade for the detection of hard x-rays was tested at the Sub-Picosecond Photon Source in Stanford.

  3. Development of gamma-photon/Cerenkov-light hybrid system for simultaneous imaging of I-131 radionuclide

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi; Suzuki, Mayumi; Kato, Katsuhiko [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine (Japan); Ogata, Yoshimune [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Hatazawa, Jun [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine (Japan)

    2016-09-11

    Although iodine 131 (I-131) is used for radionuclide therapy, high resolution images are difficult to obtain with conventional gamma cameras because of the high energy of I-131 gamma photons (364 keV). Cerenkov-light imaging is a possible method for beta emitting radionuclides, and I-131 (606 MeV maximum beta energy) is a candidate to obtain high resolution images. We developed a high energy gamma camera system for I-131 radionuclide and combined it with a Cerenkov-light imaging system to form a gamma-photon/Cerenkov-light hybrid imaging system to compare the simultaneously measured images of these two modalities. The high energy gamma imaging detector used 0.85-mm×0.85-mm×10-mm thick GAGG scintillator pixels arranged in a 44×44 matrix with a 0.1-mm thick reflector and optical coupled to a Hamamatsu 2 in. square position sensitive photomultiplier tube (PSPMT: H12700 MOD). The gamma imaging detector was encased in a 2 cm thick tungsten shield, and a pinhole collimator was mounted on its top to form a gamma camera system. The Cerenkov-light imaging system was made of a high sensitivity cooled CCD camera. The Cerenkov-light imaging system was combined with the gamma camera using optical mirrors to image the same area of the subject. With this configuration, we simultaneously imaged the gamma photons and the Cerenkov-light from I-131 in the subjects. The spatial resolution and sensitivity of the gamma camera system for I-131 were respectively ~3 mm FWHM and ~10 cps/MBq for the high sensitivity collimator at 10 cm from the collimator surface. The spatial resolution of the Cerenkov-light imaging system was 0.64 mm FWHM at 10 cm from the system surface. Thyroid phantom and rat images were successfully obtained with the developed gamma-photon/Cerenkov-light hybrid imaging system, allowing direct comparison of these two modalities. Our developed gamma-photon/Cerenkov-light hybrid imaging system will be useful to evaluate the advantages and disadvantages of these two

  4. Detector for the liquid carried over in a gas

    International Nuclear Information System (INIS)

    Delisle, J.P.; Eperonnat, P.; Lions, N.

    1965-01-01

    This report describes an optical detector for the detection of a liquid carried over by a gas. The device is sensitive to a cumulated quantity of liquid equal to a few cubic millimetres and is capable of operating an alarm from a distance. The prototype was constructed and tested as detector for the oil leaking in the argon compressed by a diaphragm compressor. A patent for this apparatus under the number: P.V.954.703, has been deposited on 22.11.1963. (authors) [fr

  5. Cerenkov methodology for monitoring irradiated reactor fuel

    International Nuclear Information System (INIS)

    Nicholson, N.; Dowdy, E.J.

    1984-01-01

    Attribute measurement methods for confirming declared irradiated fuel inventories at nuclear installations under safeguards surveillance are of significant interest to inspectors. High-gain measurements of the intensity of the Cerenkov glow from exposed assemblies in water-filled storage ponds are promising for this purpose because the measured intensities depend on cooling times and burnup. We have developed a Cerenkov Measuring Device, a hand-held instrument that examines irradiated fuel assemblies in water-filled storage ponds and measures the intensity of the associated Cerenkov glow. In addition, we have developed a method for making such high-gain measurements in the presence of intense ambient light

  6. Pad readout for gas detectors using 128-channel integrated preamplifiers

    International Nuclear Information System (INIS)

    Fischer, P.; Drees, A.; Glassel, P.

    1988-01-01

    A novel two-dimensional readout scheme for gas detectors is presented which uses small metal pads with 2.54 mm pitch as an anode. The pads are read out via 128-channel VLSI low-noise preamplifier/multiplexer chips. These chips are mounted on 2.8x2.8 cm/sup 2/ modules which are directly plugged onto the detector backplane, daisy-chained with jumpers and read out sequentially. The readout has been successfully tested with a low-pressure, two-step, TMAE-filled UV-RICH detector prototype. A single electron efficiently of >90% was observed at moderate chamber gains (<10/sup 6/). The method offers high electronic amplification, low noise, and high readout speed with a very flexible and compact design, suited for space-limited applications

  7. Colour quenching corrections on the measurement of {sup 90}Sr through Cerenkov counting

    Energy Technology Data Exchange (ETDEWEB)

    Mosqueda, F. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21071 Huelva (Spain)], E-mail: fernando.mosqueda@dfa.uhu.es; Villa, M. [Centro de Investigacion, Tecnologia e Innovacion, Universidad de Sevilla, Av. Reina Mercedes 4B, E41012 Sevilla (Spain); Vaca, F.; Bolivar, J.P. [Dpto. de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus de El Carmen, 21071 Huelva (Spain)

    2007-12-05

    The determination of {sup 90}Sr through the Cerenkov radiation emitted by its descendant {sup 90}Y is a well-known method and firmly established in literature. Nevertheless, in order to obtain an accurate result based on a Cerenkov measurement, the experimental work must be extremely rigorous because the efficiency of Cerenkov counting is especially sensitive to the presence of colour. Any traces of colour in the sample produce a decrease in the number of photons detected in the photomultipliers and, therefore, this might cause a diminution in Cerenkov counting efficiency. It is essential not only to detect the effect of colour quenching in the sample but also to correct the decrease in counting efficiency. For this reason, colour quenching correction curves versus counting efficiency are usually done when measuring through Cerenkov counting. One of the most widely used techniques to evaluate colour quenching in these measurements is the channel ratio method, which consists of the measurement of the shift of the spectrum measuring the ratio of counts in two different windows. The selection of the windows for the application of the corrections might have an influence on the quality of the fitting parameters of the correction curves efficiency versus colour quenching degree and hence on the final {sup 90}Sr result. This work is focused on the calculation of the counting efficiency decrease using the channel ratio method and on obtaining the best fitting correction curve. For this purpose, empirical curves obtained through artificial quenchers have been studied and the results have been tested in real samples. Additionally, given that the Packard Tri-Carb 3170 TR/SL liquid scintillation counter is a novel detector for use in Cerenkov counting, the previous calibration of the Tri-Carb 3170 TR/SL detector, necessary for the measurement of {sup 90}Sr, is included.

  8. Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip

    International Nuclear Information System (INIS)

    Cho, Jennifer S; Taschereau, Richard; Olma, Sebastian; Liu Kan; Chen Yichun; Shen, Clifton K-F; Van Dam, R Michael; Chatziioannou, Arion F

    2009-01-01

    It has been observed that microfluidic chips used for synthesizing 18 F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since 18 F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.e. electrons or positrons, to generate Cerenkov radiation was calculated for water and polydimethylsiloxane (PDMS), the most commonly used polymer-based material for microfluidic chips. Beta particles emitted from 18 F have a continuous energy spectrum, with a maximum energy that exceeds this energy threshold for both water and PDMS. In addition, the spectral characteristics of the emitted light from 18 F in distilled water were also measured, yielding a broad distribution from 300 nm to 700 nm, with higher intensity at shorter wavelengths. A photograph of the 18 F solution showed a bluish-white light emitted from the solution, further suggesting Cerenkov radiation. In this study, the feasibility of using this Cerenkov light emission as a method for quantitative measurements of the radioactivity within the microfluidic chip in situ was evaluated. A detector previously developed for imaging microfluidic platforms was used. The detector consisted of a charge-coupled device (CCD) optically coupled to a lens. The system spatial resolution, minimum detectable activity and dynamic range were evaluated. In addition, the calibration of a Cerenkov signal versus activity concentration in the microfluidic chip was determined. This novel method of Cerenkov radiation measurements will provide researchers with a simple yet robust quantitative imaging tool for microfluidic applications utilizing beta particles.

  9. Colour quenching corrections on the measurement of 90Sr through Cerenkov counting

    International Nuclear Information System (INIS)

    Mosqueda, F.; Villa, M.; Vaca, F.; Bolivar, J.P.

    2007-01-01

    The determination of 90 Sr through the Cerenkov radiation emitted by its descendant 90 Y is a well-known method and firmly established in literature. Nevertheless, in order to obtain an accurate result based on a Cerenkov measurement, the experimental work must be extremely rigorous because the efficiency of Cerenkov counting is especially sensitive to the presence of colour. Any traces of colour in the sample produce a decrease in the number of photons detected in the photomultipliers and, therefore, this might cause a diminution in Cerenkov counting efficiency. It is essential not only to detect the effect of colour quenching in the sample but also to correct the decrease in counting efficiency. For this reason, colour quenching correction curves versus counting efficiency are usually done when measuring through Cerenkov counting. One of the most widely used techniques to evaluate colour quenching in these measurements is the channel ratio method, which consists of the measurement of the shift of the spectrum measuring the ratio of counts in two different windows. The selection of the windows for the application of the corrections might have an influence on the quality of the fitting parameters of the correction curves efficiency versus colour quenching degree and hence on the final 90 Sr result. This work is focused on the calculation of the counting efficiency decrease using the channel ratio method and on obtaining the best fitting correction curve. For this purpose, empirical curves obtained through artificial quenchers have been studied and the results have been tested in real samples. Additionally, given that the Packard Tri-Carb 3170 TR/SL liquid scintillation counter is a novel detector for use in Cerenkov counting, the previous calibration of the Tri-Carb 3170 TR/SL detector, necessary for the measurement of 90 Sr, is included

  10. Charge Transfer Properties Through Graphene Layers in Gas Detectors

    CERN Document Server

    Thuiner, P.; Jackman, R.B.; Müller, H.; Nguyen, T.T.; Oliveri, E.; Pfeiffer, D.; Resnati, F.; Ropelewski, L.; Smith, J.A.; van Stenis, M.; Veenhof, R.

    2016-01-01

    Graphene is a single layer of carbon atoms arranged in a honeycomb lattice with remarkable mechanical, electrical and optical properties. For the first time graphene layers suspended on copper meshes were installed into a gas detector equipped with a gaseous electron multiplier. Measurements of low energy electron and ion transfer through graphene were conducted. In this paper we describe the sample preparation for suspended graphene layers, the testing procedures and we discuss the preliminary results followed by a prospect of further applications.

  11. Radiation-Hard Quartz Cerenkov Calorimeters

    International Nuclear Information System (INIS)

    Akgun, U.; Onel, Y.

    2006-01-01

    New generation hadron colliders are going to reach unprecedented energies and radiation levels. Quartz has been identified as a radiation-hard material that can be used for Cerenkov calorimeters of the future experiments. We report from the radiation hardness tests performed on quartz fibers, as well as the characteristics of the quartz fiber and plate Cerenkov calorimeters that have been built, designed, and proposed for the CMS experiment

  12. Performance of microstrip and microgap gas detectors at high pressure

    International Nuclear Information System (INIS)

    Fraga, F.A.F.; Fraga, M.M.F.R.; Marques, R.F.; Margato, L.M.S.; Goncalo, J.R.; Policarpo, A.J.P.L.

    1997-01-01

    A study of the operation of microstrip and microgap detectors at various gas pressures up to 6 bar with Kr-CO 2 , Xe-CO 2 and Xe-CH 4 is presented. The data were collected with a microstrip (1000 μm pitch) and a microgap (200 μm pitch) detector using a clean chamber and gas system. It is shown that maximum gain is strongly dependent on pressure and gains as high as 9 x 10 3 were obtained with Kr-CO 2 at 6 bar with a MSGC. With the smaller-pitch MGC we could get a gain of 180 with Xe-CH 4 at 6 bar; the typical energy resolution at 22 keV being about 15%. From the present work one can conclude that microstructures can operate at high pressure and that their application in high-efficiency, low-granularity X-ray detectors with an energy range up to a few tens of keV can be seriously considered. (orig.)

  13. Description of the SAltro-16 chip for gas detector readout

    CERN Document Server

    Aspell, P; Garcia Garcia, E; de Gaspari, M; Mager, M; Musa, L; Rehman, A; Trampitsch, G

    2010-01-01

    The S-ALTRO prototype chip is a mixed-signal integrated circuit designed to be one of the building blocks of the readout electronics for gas detectors. Its architecture is based in the ALTRO (ALICE TPC Read Out) chip, being its main difference the integration of the charge shaping amplifier in the same IC. Just like ALTRO chip, the prototype architecture and programmability make it suitable for the readout of a wider class of detectors. In one single chip, 16 analogue signals from the detector are shaped, digitised, processed, compressed and stored in a multi-acquisition memory. The Analogue-to- Digital converters embedded in the chip have a 10-bit dynamic range and a maximum sampling rate up to 40MHz. After digitisation, a pipelined Data Processor is able to remove from the input signal a wide range of perturbations, related to the non- ideal behaviour of the detector, temperature variation of the electronics, environmental noise, etc. Moreover, the Data Processor is able to suppress the pulse tail within 1�...

  14. High spatial and time resolutions with gas ionization detectors

    International Nuclear Information System (INIS)

    Pouthas, J.

    2001-09-01

    This document presents the principles and the characteristics of the gaseous ionisation detectors used in position and timing measurements. The first two parts recall the main notions (electron and ion motions, gaseous amplification, signal formation) and their applications to the proportional counter and the wire chamber. The explanation of the signal formation makes use of the Ramo theorem. The third part is devoted to the different types of wire chambers: drift or cathode strip chambers, TPC (time projection chamber). Some aspects on construction and ageing are also presented. Part 4 is on the detectors in which the multiplication is performed by a 'Parallel Plate' system (PPAC, Pestov counter). Special attention is paid to the RPCs (Resistive Plate Chambers) and their timing resolutions. Part 5 concentrates on 'Micro-pattern detectors' which use different kinds of microstructure for gaseous amplification. The new detectors MICROMEGAS, CAT (compteur a trous) and GEM (gas electron multiplier) and some of their applications are presented. The last part is a bibliography including some comments on the documents. (author)

  15. Gas pixel detector for X-ray observation

    CERN Document Server

    Attié, D; Chefdeville, M; Colas, P; Delagnes, E; Giomataris, Y; van der Graaf, H; Llopart, X; Timmermans, J; Visschers, J

    2009-01-01

    We report on the status of the R&D for a digital Time Projection Chamber (TPC) based on Micromegas (MICRO MEsh GAseous Structure) detectors using the CMOS chip TimePix as a direct readout anode protected by highly resistive a-Si:H layer. A small chamber was built as a demonstrator of the 2-D and 3-D imaging capabilities of this technique. We illustrate the new capabilities of this detector for X-ray observation with data taken from radioactive sources. This small TPC is a very useful tool both for studying gas properties thanks to its good efficiency for single electrons, and for reconstructing photoelectron direction for use as a soft X-ray polarimeter.

  16. Measurement of the position resolution of the Gas Pixel Detector

    International Nuclear Information System (INIS)

    Soffitta, Paolo; Muleri, Fabio; Fabiani, Sergio; Costa, Enrico; Bellazzini, Ronaldo; Brez, Alessandro; Minuti, Massimo; Pinchera, Michele; Spandre, Gloria

    2013-01-01

    The Gas Pixel Detector was designed and built as a focal plane instrument for X-ray polarimetry of celestial sources, the last unexplored subtopics of X-ray astronomy. It promises to perform detailed and sensitive measurements resolving extended sources and detecting polarization in faint sources in crowded fields at the focus of telescopes of good angular resolution. Its polarimetric and spectral capability were already studied in earlier works. Here we investigate for the first time, with both laboratory measurements and Monte Carlo simulations, its imaging properties to confirm its unique capability to carry out imaging spectral-polarimetry in future X-ray missions.

  17. Gas microstrip detectors on polymer, silicon and glass substrates

    International Nuclear Information System (INIS)

    Barasch, E.F.; Demroff, H.P.; Drew, M.M.; Elliott, T.S.; Gaedke, R.M.; Goss, L.T.; Kasprowicz, T.B.; Lee, B.; Mazumdar, T.K.; McIntyre, P.M.; Pang, Y.; Smith, D.D.; Trost, H.J.; Vanstraelen, G.; Wahl, J.

    1993-01-01

    We present results on the performance of Gas Microstrip Detectors on various substrates. These include a 300 μm anode-anode pitch pattern on Tempax borosilicate glass and ABS/copolyether, a 200 μm pattern on Upilex ''S'' polyimide, Texin 4215, Tedlar, ion-implanted Kapton, orientation-dependent etched flat-topped silicon (''knife-edge chamber''), and iron-vanadium glass, and a 100 μm pitch pattern on Upilex ''S'' and ion-implanted Kapton. (orig.)

  18. An X-ray gas position sensitive detector: construction and characterization

    International Nuclear Information System (INIS)

    Barbosa, A.F.; Gabriel, A.; Gabriel, A.; Craievich, A.

    1988-01-01

    A linear x-ray gas position sensitive detector with delay line readout has been constructed. The detector is described, characterized and used for detecting x-ray diffraction patterns from polycrystals. (author) [pt

  19. Radiation damage: special reference to gas filled radiation detectors

    International Nuclear Information System (INIS)

    Gaur, Sudha; Joshi, Pankaj Kumar; Rathore, Shakuntla

    2012-01-01

    Radiation damage is a term associated with ionizing radiation. In gas filled particle detectors, radiation damage to gases plays an important role in the device's ageing, especially in devices exposed to high intensity radiation, e.g. detector for the large hadrons collide. Ionization processes require energy above 10 eV, while splitting covalent bond in molecules and generating free radical require only 3-4 eV. The electrical discharges initiated by the ionization event by the particles result in plasma populated by large amount of free radical. The highly reactive free radical can recombine back to original molecules, or initiate a chain of free radical polymerization reaction with other molecules, yielding compounds with increasing molecular weight. These high molecular weight compounds then precipitate from gases phase, forming conductive or non-conductive deposits on the electrodes an insulating surfaces of the detector and distorting it's response. Gases containing hydrocarbon quenchers, e.g. argon-methane, are typically sensitive to ageing by polymerization; addition of oxygen tends to lower the ageing rates. Trace amount of silicon oils, present form out gassing of silicon elastomers and especially from traces of silicon lubricant tend to decompose and form deposits of silicon crystals on the surfaces. Gases mixture of argon (or xenon) with CO 2 and optimally also with 2-3 % of oxygen are highly tolerant to high radiation fluxes. The oxygen is added as noble gas with CO 2 has too high transparency for high energy photons; ozone formed from the oxygen is a strong absorber of ultra violet photons. Carbon tetra fluoride can be used as a component of the gas for high-rate detectors; the fluorine radical produced during the operation however limit the choice of materials for the chambers and electrodes (e.g. gold electrodes are required, as the fluorine radicals attack metals, forming fluorides). Addition of carbon tetra fluoride can however eliminate the

  20. Study of gel materials as radioactive 222Rn gas detectors

    International Nuclear Information System (INIS)

    Espinosa, G.; Golzarri, J. I.; Rickards, J.; Gammage, R. B.

    2006-01-01

    Commercial hair gel material (polyvinyl pyrolidone triethanolamine carbo-pol in water) and bacteriological agar (phycocolloid extracted from a group of red-purple algae, usually Gelidium sp.) have been studied as radioactive radon gas detectors. The detection method is based on the diffusion of the radioactive gas in the gel material, and the subsequent measurement of trapped products of the natural decay of radon by gamma spectrometry. From the several radon daughters with gamma radiation emission ( 214 Pb, 214 Bi, 214 Po, 210 Pb, 210 Po), two elements, 214 Pb (0.352 MeV) and 214 Bi (0.609 MeV), were chosen for the analysis in this work; in order to determine the best sensitivity, corrections were made for the short half-life of the analysed isotopes. For the gamma spectrometry analysis, a hyper-pure germanium solid state detector was used, associated with a PC multichannel analyser card with Maestro R and Microsoft R Excel R software. The results show the viability of the method: a linear response in a wide radon concentration range (450-10,000 Bq m -3 ), reproducibility of data, easy handling and low cost of the gel material. This detection methodology opens new possibilities for measurements of radon and other radioactive gases. (authors)

  1. The potential of a Cerenkov Array for Supersymmetry and Cosmology

    International Nuclear Information System (INIS)

    Vasileiadis, G.; Falvard, A.; Giraud, E.; Lavalle, J.; Sajjad, S.

    2005-01-01

    If R-parity is sufficiently well conserved, most of the supersymmetric models predict the existence of a stable, neutral particle, the neutralino, which would be a natural candidate for dark matter. Such particles can annihilate through various channels producing in particular, a faint flux of high energy photons in galactic and extragalactic high density regions. We have considered the potential of a Cerenkov array for exploring a significant fraction of the supersymmetric parameter space. The main constraints are the flux limit, which requires a very large effective area, and the energy threshold which needs reaching lower limit of the order of 15-20 GeV due to the lowest neutralino mass given by accelerators. Combining such constraints leads to an array of at least 16-19 Cerenkov reflectors with diameters of the order of 18m, located at high altitude (5000 m). This instrument would combine wide angle camera and large detection areas. It would also serve as a major tool in Observational Cosmology and Astrophysics above 15-20 GeV up to 1 TeV. Coming after GLAST, it would allow studying in details, at higher energy, the sources detected by this satellite. This instrument would not be able to explore the 10 GeV to sub-10 GeV domain unless higher QE detectors are discovered or larger diameters are considered. A very interesting site would be the Chajnantor-Toco area for this project which requires clear UBV photometric nights

  2. The development of an electrochemical technique for in situ calibrating of combustible gas detectors

    Science.gov (United States)

    Shumar, J. W.; Lantz, J. B.; Schubert, F. H.

    1976-01-01

    A program to determine the feasibility of performing in situ calibration of combustible gas detectors was successfully completed. Several possible techniques for performing the in situ calibration were proposed. The approach that showed the most promise involved the use of a miniature water vapor electrolysis cell for the generation of hydrogen within the flame arrestor of a combustible gas detector to be used for the purpose of calibrating the combustible gas detectors. A preliminary breadboard of the in situ calibration hardware was designed, fabricated and assembled. The breadboard equipment consisted of a commercially available combustible gas detector, modified to incorporate a water vapor electrolysis cell, and the instrumentation required for controlling the water vapor electrolysis and controlling and calibrating the combustible gas detector. The results showed that operation of the water vapor electrolysis at a given current density for a specific time period resulted in the attainment of a hydrogen concentration plateau within the flame arrestor of the combustible gas detector.

  3. Mitigating gas emissions at signalised intersections using wireless vehicle detectors

    Directory of Open Access Journals (Sweden)

    Moses Kwasi Torkudzor

    2015-09-01

    Full Text Available Traffic congestion on roads wastes travel times and increases fuel consumption as well as gas emissions which are dangerous to human health. This has led to growing concern about environmental protection and energy conservation and a number of studies to increase fuel economy and reduce gas emissions. To increase travel times so as to reduce fuel consumption and gas emissions, traffic signals at intersections must be well implemented. It is therefore necessary to employ the current technology of wireless sensor networks to enhance the optimisation of the signalised intersections so as to address such a concern. In this study, a vehicular traffic control model was developed to optimise a signalised intersection, using wireless vehicle detectors. Real-time traffic volume gathered were analysed to obtain the peak hour traffic volume causing congestion. The intersection was modelled and simulated in Synchro7 as an actuated signalised model using results from the analysed data. The model for morning peak and evening peak periods gave optimal cycle lengths which result in the reduction of gas emissions, fuel consumption and delay at the intersection.

  4. Imaging with SiPMs in noble-gas detectors

    International Nuclear Information System (INIS)

    Yahlali, N; González, K; Fernandes, L M P; Garcia, A N C; Soriano, A

    2013-01-01

    Silicon photomultipliers (SiPMs) are photosensors widely used for imaging in a variety of high energy and nuclear physics experiments. In noble-gas detectors for double-beta decay and dark matter experiments, SiPMs are attractive photosensors for imaging. However they are insensitive to the VUV scintillation emitted by the noble gases (xenon and argon). This difficulty is overcome in the NEXT experiment by coating the SiPMs with tetraphenyl butadiene (TPB) to convert the VUV light into visible light. TPB requires stringent storage and operational conditions to prevent its degradation by environmental agents. The development of UV sensitive SiPMs is thus of utmost interest for experiments using electroluminescence of noble-gas detectors. It is in particular an important issue for a robust and background free ββ0ν experiment with xenon gas aimed by NEXT. The photon detection efficiency (PDE) of UV-enhanced SiPMs provided by Hamamatsu was determined for light in the range 250–500 nm. The PDE of standard SiPMs of the same model (S10362-33-50C), coated and non-coated with TPB, was also determined for comparison. In the UV range 250–350 nm, the PDE of the standard SiPM is shown to decrease strongly, down to about 3%. The UV-enhanced SiPM without window is shown to have the maximum PDE of 44% at 325 nm and 30% at 250 nm. The PDE of the UV-enhanced SiPM with silicon resin window has a similar trend in the UV range, although it is about 30% lower. The TPB-coated SiPM has shown to have about 6 times higher PDE than the non-coated SiPM in the range 250–315 nm. This is however below the performance of the UV-enhanced prototypes in the same wavelength range. Imaging in noble-gas detectors using UV-enhanced SiPMs is discussed.

  5. Particle detection and identification through Cerenkov effect in silica aerogels

    International Nuclear Information System (INIS)

    Engelmann, J.J.; Cantin, M.

    1978-01-01

    Cerenkov counters are largely used in high energy physics and in nuclear astrophysics to identify the charge of high energy particles and to measure their velocity. Good velocity resolution is obtained only near the Cerenkov threshold, which is directly dependent on the refractive index of the radiator. It is therefore very important to dispose of materials of various refractive indices. The silica aerogel allows to cover a range of indices between 1.015 and 1.2 which is intermediate between the indices given by gas and liquids. The samples most often built until now are hexagonal blocks of 1.06 refractive index and 0.24 g/cm 3 density. Blocks of one liter in volume have been assembled to form a mosaic of large dimension. For lower refractive indices, 1.015 for instance, the material becomes too brittle. So we have been led to use an aerogel sand made of aerogel grains of controlled granulometry. Radiators of both types blocks and sand are used in the franco-danish experiment to be launched aboard the NASA satellite HEAO-C in July 1979 [fr

  6. X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

    CERN Document Server

    Nakagawa, A; Yoshida, T

    2003-01-01

    This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

  7. Features and performance of a large gas Cherenkov detector with threshold regulation

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, J.; Alvarez-Taviel, J.; Asenjo, L.; Colino, N.; Diez-Hedo. F.; Duran, I.; Gonzalez, J.; Hernandez, J.J.; Ladron de Guevara, P.; Marquina, M.A.

    1988-01-15

    We present here the development, main features and calibration procedures for a new type of gas Cherenkov detector, based upon the ability to control its threshold by regulating the temperature of the gas used as radiator. We also include the performance of this detector in particle identification.

  8. Properties of potential eco-friendly gas replacements for particle detectors in high-energy physics

    Science.gov (United States)

    Saviano, G.; Ferrini, M.; Benussi, L.; Bianco, S.; Piccolo, D.; Colafranceschi, S.; KjØlbro, J.; Sharma, A.; Yang, D.; Chen, G.; Ban, Y.; Li, Q.; Grassini, S.; Parvis, M.

    2018-03-01

    Gas detectors for elementary particles require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This work studies properties of potential eco-friendly gas replacements by computing the physical and chemical parameters relevant for use as detector media, and suggests candidates to be considered for experimental investigation.

  9. Notification determining technical standards concerning prevention of radiation injuries by electron capture detectors for gas chromatography

    International Nuclear Information System (INIS)

    1981-01-01

    This rule is established under the provisions of the law on the prevention of radiation injuries by radioisotopes, the ordinance and the regulation for the execution of the law. This rule is applied to electron capture detectors for gas chromatography under the law. Basic terms are defined, such as detector radiation source, detector container and carrier gas. The detectors shall consist of detector radiation sources and containers, and the containers must be such that the radiation sources can not be easily taken away and never cause the danger to fall off. The induction and discharge mouths of the detector containers shall be shut tightly with caps, etc. The main structures and radiation sources of detectors shall be made of materials, which are difficult to corrode, and do not melt and easily cause chemical change below 800 deg. C. Detector radiation sources shall be made of metals plated with nickel 63 less than 20 milli-curie. The radiation dose rate on the surface of a detector shall be shielded to less than 0.06 milli-rem an hour. The temperature of detectors and carrier gas shall not exceed 350 deg. C. Corrosive gas shall not be used as carrier gas. The period of effective indication is 5 years. The method of washing, and the conditions of leak, heat-resistance and shock-resistance examinations are defined, respectively. (Okada, K.)

  10. Development of data logger for atmospheric pressure, temperature and relative humidity for gas-filled detector

    International Nuclear Information System (INIS)

    Sahu, S.; Sahu, P.K.; Bhuyan, M.R.; Biswas, S.; Mohanty, B.

    2014-01-01

    At IoP-NISER an initiative has been taken to build and test micro-pattern gas detector such as Gas Electron Multiplier (GEM) for several upcoming High-Energy Physics (HEP) experiment projects. Temperature (t), atmospheric pressure (p) and relative humidity (RH) monitor and recording is very important for gas filled detector development. A data logger to monitor and record the ambient parameters such as temperature, relative humidity and pressure has been developed. With this data logger continuous recording of t, p, RH and time stamp can be done with a programmable sampling interval. This data is necessary to correct the gain of a gas filled detector

  11. Plastic scintillation dosimetry for radiation therapy: minimizing capture of Cerenkov radiation noise

    International Nuclear Information System (INIS)

    Beddar, A Sam; Suchowerska, Natalka; Law, Susan H

    2004-01-01

    Over the last decade, there has been an increased interest in scintillation dosimetry using small water-equivalent plastic scintillators, because of their favourable characteristics when compared with other more commonly used detector systems. Although plastic scintillators have been shown to have many desirable dosimetric properties, as yet there is no successful commercial detector system of this type available for routine clinical use in radiation oncology. The main factor preventing this new technology from realizing its full potential in commercial applications is the maximization of signal coupling efficiency and the minimization of noise capture. A principal constituent of noise is Cerenkov radiation. This study reports the calculated capture of Cerenkov radiation by an optical fibre in the special case where the radiation is generated by a relativistic particle on the fibre axis and the fibre axis is parallel to the Cerenkov cone. The fraction of radiation captured is calculated as a function of the fibre core refractive index and the refractive index difference between the core and the cladding of the fibre for relativistic particles. This is then used to deduce the relative intensity captured for a range of fibre core refractive indices and fibre core-cladding refractive index differences. It is shown that the core refractive index has little effect on the amount of radiation captured compared to the refractive index difference. The implications of this result for the design of radiation therapy plastic scintillation dosimeters are considered

  12. A gas microstrip wide angle X-ray detector for application in synchrotron radiation experiments

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Lipp, J; Mir, J A; Simmons, J E; Spill, E J; Stephenson, R; Dobson, B R; Farrow, R C; Helsby, W I; Mutikainen, R; Suni, I

    2002-01-01

    The Gas Microstrip Detector has counting rate capabilities several orders of magnitude higher than conventional wire proportional counters while providing the same (or better) energy resolution for X-rays. In addition the geometric flexibility provided by the lithographic process combined with the self-supporting properties of the substrate offers many exciting possibilities for X-ray detectors, particularly for the demanding experiments carried out on Synchrotron Radiation Sources. Using experience obtained in designing detectors for Particle Physics we have developed a detector for Wide Angle X-ray Scattering studies. The detector has a fan geometry which makes possible a gas detector with high detection efficiency, sub-millimetre spatial resolution and good energy resolution over a wide range of X-ray energy. The detector is described together with results of experiments carried out at the Daresbury Laboratory Synchrotron Radiation Source.

  13. An improved multiple flame photometric detector for gas chromatography.

    Science.gov (United States)

    Clark, Adrian G; Thurbide, Kevin B

    2015-11-20

    An improved multiple flame photometric detector (mFPD) is introduced, based upon interconnecting fluidic channels within a planar stainless steel (SS) plate. Relative to the previous quartz tube mFPD prototype, the SS mFPD provides a 50% reduction in background emission levels, an orthogonal analytical flame, and easier more sensitive operation. As a result, sulfur response in the SS mFPD spans 4 orders of magnitude, yields a minimum detectable limit near 9×10(-12)gS/s, and has a selectivity approaching 10(4) over carbon. The device also exhibits exceptionally large resistance to hydrocarbon response quenching. Additionally, the SS mFPD uniquely allows analyte emission monitoring in the multiple worker flames for the first time. The findings suggest that this mode can potentially further improve upon the analytical flame response of sulfur (both linear HSO, and quadratic S2) and also phosphorus. Of note, the latter is nearly 20-fold stronger in S/N in the collective worker flames response and provides 6 orders of linearity with a detection limit of about 2.0×10(-13)gP/s. Overall, the results indicate that this new SS design notably improves the analytical performance of the mFPD and can provide a versatile and beneficial monitoring tool for gas chromatography. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Irradiated fuel examination using the Cerenkov technique

    International Nuclear Information System (INIS)

    Nicholson, N.; Dowdy, E.J.

    1981-03-01

    A technique for monitoring irradiated nuclear fuel inventories located in water filled storage ponds has been developed and demonstrated. This technique provides sufficient qualitative information to be useful as a confirmatory technique to International Atomic Energy Agency inspectors. Measurements have been made on the Cerenkov glow light intensity from irradiated fuel that show the intensity of this light to be proportional to the cooling time. Fieldable instruments used in several tests confirm that such measurements can be made easily and rapidly, without fuel assembly movement or the introduction of apparatus into the storage ponds. The Cerenkov technique and instrumentation have been shown to be of potential use to operators of reactor spent fuel facilities and away from reactor storage facilities, and to the International Atomic Energy Agency inspectors who provide surveillance of the irradiated fuel stored in these facilities

  15. Cherenkov radiation; La radiation Cerenkov

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

  16. Domestic Preparedness Program: Evaluation of the Agilent Gas Chromatograph - Flame Photometric Detector/Mass Selective Detector (GC-FPD/MSD) System Against Chemical Warfare Agents Summary Report

    National Research Council Canada - National Science Library

    Longworth, Terri

    2003-01-01

    This report characterizes the chemical warfare agent (CWA) detection potential of the commercially available Agilent gas chromatograph-flame photometric detector/mass selective detector (GC-FPD/MSD...

  17. Particle identification in Lep-Delphi experience. Experimental study of photoelectron detection and of Cerenkov angle resolution with the Barrel Rich prototype

    International Nuclear Information System (INIS)

    Dracos, M.

    1987-06-01

    One of the four LEP experiments, DELPHI, will be equipped with Ring Cherenkov (RICH) detectors for hadrons identification. These detectors will provide pion, kaon, proton identification for momenta from 0.3 to 25 GeV/c over nearly all the solid angle. The technique of the long drift is used which combines liquid and gas radiators on opposite sides of a simple photosensitive drift volume. A full-scale prototype of the DELPHI Barrel RICH was built to study the feasibility and the performances of a big RICH system. We have obtained: - an absorption length of photoelectrons in the drift gas more than 10 m; - a merit factor of 53 cm -1 for the liquid radiator (perfluoro-hexane C 6 F 14 ) and 77 cm -1 for the gas radiator (isobutance iC 4 H 10 ) - a resolution of the single photon Cerenkov angle of 11.5 mrad for the liquid radiator and 4.5 mrad for the gas radiator [fr

  18. Study of a total reflection Cerenkov counter

    International Nuclear Information System (INIS)

    Didelez, J.P.

    1979-01-01

    A Monte Carlo program simulates the emission and collection of Cerenkov light due to P and π (0.6 to 1.4 GeV/c) going through a rectangular parallelepiped of plexiglas. Without taking into account the knocked out electrons (delta) a good theoretical separation is obtained between P and π. The contribution of delta electrons has been calculated separately. Experimental tests are under way using cosmic rays [fr

  19. Development of a sodium ionization detector for sodium-to-gas leaks

    International Nuclear Information System (INIS)

    Swaminathan, K.; Elumalai, G.

    1984-01-01

    A sensitive sodium-to-gas leak detector has been indigenously developed for use in liquid metal cooled fast breeder reactor. The detector relies on the relative ease with which sodium vapour or its aerosols including its oxides and hydroxides can be thermally ionized compared with other possible constituents such as nitrogen, oxygen, water vapour etc. in a carrier gas and is therefore called sodium ionization detector (SID). The ionization current is a measure of sodium concentration in the carrier gas sampled through the detector. Different sensor designs using platinum and rhodium as filament materials in varying sizes were constructed and their responses to different sodium aerosol concentrations in the carrier gas were investigated. Nitrogen was used as the carrier gas. Both the background current and speed of response were found to depend on the diameter of the filament. There was also a particular collector voltage which yielded maximum sensitivity of the detector. The sensor was therefore optimised considering influence of above factors and a detector has been built which demonstrates a sensitivity better than 0.3 nanogram of sodium per cubic centimetre of carrier gas for a signal to background ratio of 1:1. Its usefulness in detecting sodium fires in experimental area was also demonstrated. Currently efforts are under way to improve the life time of the filament used in the above detector. (author)

  20. Measurement of the pulse night spectrum Cerenkov flashes in the atmosphere

    International Nuclear Information System (INIS)

    Schlemmer, G.

    1981-03-01

    The determination of the energy spectrum of Cosmic Rays is difficult because of the low particle density at high energies. Normally such observations would require detectors with large collecting areas and long measurement periods. However the difficulty can be overcome by measuring shower induced Cerenkov radiation, the photon density of which is proportional to the shower energy. The Cerenkov radiation measurements reported here were made using two photomultipliers connected to a coincidence counter unit. The shower energy was deduced from measurements of the height of the pulses observed at the multiplier output,which should be proportional to the number of Cerenkov photons arriving at the photocathode. In order to make meaningful statements about the shower energy the statistical response of the photomultiplier system had to be standardized. This calibration was carried out by illuminating the photomultiplier cathode with a pulsed LED of pulsewidth 5 ns. For different light intensities of the LED a pulse-height spectrum was taken at the multiplier output. In addition to the Cerenkov photons counted by the photomultipliers, there exists a strong constant background light intensity. This background can be eliminated by employing a coincidence amplifier with a resolution time of 10 ns. To reduce background induced accidental coincidences the apparatus was equipped with a variable trigger level. To test the apparatus the Cerenkov radiation induced by cosmic rays in a water basin and in the photomultiplier window itself was measured and compared to theoretical estimates. The agreement was good. The pulse height spectrum of atmospheric Cerenkov radiation was obtained at the Cosmic Ray Physics Laboratory at the Hafelekar Observatory near Innsbruck. The measurements obtained there allowed the exponnent $delta in the differential energy spectrum N(E) dE c.Esup(-$delta)dE of the primary Cosmic Radiation to be evaluated. The value of $delta in the energy range 2,5 x 10 14

  1. Small angle X-ray scattering experiments with three-dimensional imaging gas detectors

    International Nuclear Information System (INIS)

    La Monaca, A.; Iannuzzi, M.; Messi, R.

    1985-01-01

    Measurements of small angle X-ray scattering of lupolen - R, dry collagen and dry cornea are presented. The experiments have been performed with synchrotron radiation and a new three-dimensional imaging drif-chamber gas detector

  2. SRD Exhibits ONR Funded Chemical Detector Technology & Supporting Gas Delivery Systems (GDS) AT PITTCON 2005

    National Research Council Canada - National Science Library

    Harmon, Andrew

    2005-01-01

    SRD attended PITTCON 2005 in Orlando, Florida with an exhibitor booth to showcase their chemical detector technology being developed for The Office of Naval Research as well as gas delivery systems (GDS...

  3. The Development of Micro-Pattern Gas Detectors

    CERN Document Server

    BALOUZA, Samah

    2014-01-01

    This work is aimed to study the electron transparency in 3-D woven mesh that is used in micromegas detector. The importance of calculating the transparency is because it is enter in the gain calibration of the detector. The simulation tool is COMSOL Multiphysics in which it is solved the differential equations by Finite Element Method.

  4. A gas microstrip X-ray detector for soft energy fluorescence EXAFS

    CERN Document Server

    Smith, A D; Derbyshire, G E; Duxbury, D M; Lipp, J; Spill, E J; Stephenson, R

    2001-01-01

    Gas microstrip detectors have been previously developed by the particle physics community, where their robustness, compactness and high counting speed have been recognised. These features are particularly attractive to synchrotron radiation use. In this paper, we describe a gas microstrip detector employing multi-element readout and specifically developed for high count rate fluorescence EXAFS at soft X-ray energies below 4 keV.

  5. Passivation of gas microstrip detectors and stability of long-term operation

    International Nuclear Information System (INIS)

    Salomon, M.; Armitage, J.; Chapman, G.; Dixit, M.; Dubeau, J.; Faszer, W.; Hamel, L.A.; Oakham, G.

    1994-01-01

    We have studied the long-term operation of gas microstrip detectors which have been passivated with a layer of nickel oxide. We have used as the active gas CF 4 /isobutane (80 : 20) and three different types of substrates: Tedlar, glass and Upilex. In all three cases we found that the detectors are stable after passivation and can operate for a month without changes in gain at rates of MHz. The total accumulated charge was approximately 100 mC. ((orig.))

  6. High gain gas microstrip detectors for soft x-ray detection

    International Nuclear Information System (INIS)

    Bateman, J.; Barlow, R.; Derbyshire, G.

    2001-01-01

    This report describes development work in which systematic changes in the pitch of the electrode pattern of a Gas Microstrip Detector are explored in the search for higher avalanche gains and enhanced stability. With the cathode width set to half of the pitch, gas gains of >50 000 are comfortably attainable with low detector noise so that x-rays can potentially be detected down to the limit of a single x-ray-produced photoelectron. (author)

  7. Optimising the design of gas microstrip detectors for soft x-ray detection

    International Nuclear Information System (INIS)

    Bateman, J.; Barlow, R.; Derbyshire, G.

    2001-01-01

    This report describes development work in which systematic changes in the electrode pattern of a Gas Microstrip Detector are explored in the search for higher avalanche gains and enhanced stability. It is found that the width of the cathode structure is the main determinant of the detector stability. With the correct cathode width, gas gains of >50 000 are comfortably attainable with low detector noise so that x-rays can potentially be detected down to the limit of a single x-ray-produced photoelectron. (author)

  8. Modern gas-avalanche radiation detectors: from innovations to applications

    International Nuclear Information System (INIS)

    2013-01-01

    Micro-Pattern Gaseous Detectors (MPGD) technologies allow for the conception of advanced large area radiation detectors with unprecedented spatial resolutions and sensitivities, capable of operating under very high radiation flux. After more than two decades of extensive R and D carried by large number of groups worldwide, these detector technologies have reached high level of maturity. Nowadays, they are adapted as leading instruments for a growing number of applications in particle physics and in many other fields on basic and applied research. The growing interest in MPGD technologies and their mass-production capabilities naturally motivates further developments in the field. The state-of-the-art detector concepts and technologies have been introduced and their evolution, properties and current leading applications have been reviewed. Future potential applications as well as new technology challenges have been discussed

  9. Low pressure gas detectors for molecular-ion break up studies

    International Nuclear Information System (INIS)

    Breskin, A.; Chechik, R.; Zwang, N.

    1981-01-01

    Two detector systems for Molecular ions like OH + and CH 2 + and like H 2 + and H 3 + were developed and are described. The first detector is installed in a magnetic spectrometer. Both systems are made of various types of gas detectors operating at low pressures. In the study of the Coulomb explosion of molecular ions like OH + , CH 2 + or H 3 + these detectors provide the position and time coordinates of all the fragments of the molecular ion, in coincidence, in order to determine their energy and angular distribution. In the case of molecules containing atoms other than hydrogen, information on the electronic charge state is obtained. (H.K.)

  10. Anomalous dispersion enhanced Cerenkov phase-matching

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, T.C.; Singer, K.D. [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Physics; Cahill, P.A. [Sandia National Labs., Albuquerque, NM (United States)

    1993-11-01

    The authors report on a scheme for phase-matching second harmonic generation in polymer waveguides based on the use of anomalous dispersion to optimize Cerenkov phase matching. They have used the theoretical results of Hashizume et al. and Onda and Ito to design an optimum structure for phase-matched conversion. They have found that the use of anomalous dispersion in the design results in a 100-fold enhancement in the calculated conversion efficiency. This technique also overcomes the limitation of anomalous dispersion phase-matching which results from absorption at the second harmonic. Experiments are in progress to demonstrate these results.

  11. A microwave inverse Cerenkov Accelerator (MICA)

    International Nuclear Information System (INIS)

    Hirshfield, Jay L.

    1999-01-01

    The objective of this Phase II SBIR research program was to complete the final design originated during Phase I for a prototype Microwave Inverse Cerenkov Accelerator (MICA), to fabricate the-prototype MICA, and to test its performance as an electron accelerator. This report contains details of the design, predictions of accelerator performance, results of cold tests on the MICA structure, and details of the installation of MICA on the Yale Beam Physics Laboratory 6-MeV beamline. Discussion of future work is also included

  12. A gas proportional scintillation counter for use in large area detector systems without photomultipliers

    International Nuclear Information System (INIS)

    Baruch, J.E.F.; Brooke, G.; Kellermann, E.W.; Bateman, J.E.; Connolly, J.F.

    1978-03-01

    The properties of a prototype gas proportional scintillation detector, for use in large numbers, are examined. The detector is designed to focus a light signal, which is proportional to ionisation loss, into a fibre optic lightguide. It is shown that a single charged particle traversing the detector produces enough light out of the lightguide to be seen by a TV camera. Problems of lifetime and large scale detector production are discussed. Properties of saturation, linearity, position sensitivity, and operating limits are examined. It is shown that an array of gas proportional scintillation detectors when used with fibre optic lightguides and TV camera readout could offer significant improvements in cost per area and reliability over a scintillator plus photomultiplier or a wire proportional chamber array. (author)

  13. Application of Gas Chromatographic analysis to RPC detectors in the ATLAS experiment at CERN-LHC

    CERN Document Server

    De Asmundis, R

    2007-01-01

    Starting from 2007 a large number (1200) Resistive Plate Chambers (RPC) detectors will be used as muon trigger detectors in the ATLAS Experiment at CERN-LHC accelerator. RPC are gaseous detector in which the quality and the stability of the gas mixture as well as the design of the gas supplying system, play a fundamental role in their functioning. RPC are foreseen to work more than ten years in the high radiation environment of ATLAS and the gas mixture acts really as a "lifeguard" for the detectors. For this reason a great attention has been devoted to the gas studies in order to optimize RPC performance, robustness and reliability in a high radiation environment. In this paper we describe the work done to decide how to supply and control in an optimal way the gas to the detectors, in order to ensure their best performance for a long time. The activity, based on Gas Chromatographic (GC) analysis, has been carried on a sample of final RPC working in radiation conditions much more intense than those foreseen f...

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

    Science.gov (United States)

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

    2008-09-07

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

  15. Gas system Upgrade for the BaBar IFR Detector at SLAC

    International Nuclear Information System (INIS)

    Foulkes, S

    2004-01-01

    A new gas distribution and monitoring system was installed as part of an upgrade of the forward endcap muon detection system (IFR) of the BaBar detector at SLAC. Over 300 gas circuits are controlled and monitored. The return gas flow is monitored by digital bubblers which use photo-gate electronics to count the bubbling rate. The rates are monitored in real time and recorded in a history database allowing studies of flow rate versus chamber performance

  16. A sensitive gas chromatography detector based on atmospheric pressure chemical ionization by a dielectric barrier discharge.

    Science.gov (United States)

    Kirk, Ansgar T; Last, Torben; Zimmermann, Stefan

    2017-02-03

    In this work, we present a novel concept for a gas chromatography detector utilizing an atmospheric pressure chemical ionization which is initialized by a dielectric barrier discharge. In general, such a detector can be simple and low-cost, while achieving extremely good limits of detection. However, it is non-selective apart from the use of chemical dopants. Here, a demonstrator manufactured entirely from fused silica capillaries and printed circuit boards is shown. It has a size of 75×60×25mm 3 and utilizes only 2W of power in total. Unlike other known discharge detectors, which require high-purity helium, this detector can theoretically be operated using any gas able to form stable ion species. Here, purified air is used. With this setup, limits of detection in the low parts-per-billion range have been obtained for acetone. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Triple GEM gas detectors as real time fast neutron beam monitors for spallation neutron sources

    International Nuclear Information System (INIS)

    Murtas, F; Claps, G; Croci, G; Tardocchi, M; Pietropaolo, A; Cippo, E Perelli; Rebai, M; Gorini, G; Frost, C D; Raspino, D; Rhodes, N J; Schooneveld, E M

    2012-01-01

    A fast neutron beam monitor based on a triple Gas Electron Multiplier (GEM) detector was developed and tested for the ISIS spallation neutron source in U.K. The test on beam was performed at the VESUVIO beam line operating at ISIS. The 2D fast neutron beam footprint was recorded in real time with a spatial resolution of a few millimeters thanks to the patterned detector readout.

  18. Cerenkov luminescence imaging of medical isotopes.

    Science.gov (United States)

    Ruggiero, Alessandro; Holland, Jason P; Lewis, Jason S; Grimm, Jan

    2010-07-01

    The development of novel multimodality imaging agents and techniques represents the current frontier of research in the field of medical imaging science. However, the combination of nuclear tomography with optical techniques has yet to be established. Here, we report the use of the inherent optical emissions from the decay of radiopharmaceuticals for Cerenkov luminescence imaging (CLI) of tumors in vivo and correlate the results with those obtained from concordant immuno-PET studies. In vitro phantom studies were used to validate the visible light emission observed from a range of radionuclides including the positron emitters (18)F, (64)Cu, (89)Zr, and (124)I; beta-emitter (131)I; and alpha-particle emitter (225)Ac for potential use in CLI. The novel radiolabeled monoclonal antibody (89)Zr-desferrioxamine B [DFO]-J591 for immuno-PET of prostate-specific membrane antigen (PSMA) expression was used to coregister and correlate the CLI signal observed with the immuno-PET images and biodistribution studies. Phantom studies confirmed that Cerenkov radiation can be observed from a range of positron-, beta-, and alpha-emitting radionuclides using standard optical imaging devices. The change in light emission intensity versus time was concordant with radionuclide decay and was also found to correlate linearly with both the activity concentration and the measured PET signal (percentage injected dose per gram). In vivo studies conducted in male severe combined immune deficient mice bearing PSMA-positive, subcutaneous LNCaP tumors demonstrated that tumor-specific uptake of (89)Zr-DFO-J591 could be visualized by both immuno-PET and CLI. Optical and immuno-PET signal intensities were found to increase over time from 24 to 96 h, and biodistribution studies were found to correlate well with both imaging modalities. These studies represent the first, to our knowledge, quantitative assessment of CLI for measuring radiotracer uptake in vivo. Many radionuclides common to both nuclear

  19. Space-Charge Effects in a Gas Detector

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.D.

    2010-12-03

    Discussion of space-charge effects in a photoluminescence cell that will be used as a nondisruptive total energy monitor at the LCLS facility is presented. Regimes where primary photoelectrons will be confined within the X-ray beam aperture are identified. Effects of the space-charge on the further evolution of the electron and ion populations are discussed. Parameters of the afterglow plasma are evaluated. Conditions under which the detector output will be proportional to the pulse energy are defined.

  20. Aging measurements on triple-GEM detectors operated with $CF_{4}$-based gas mixtures

    CERN Document Server

    Alfonsi, M; De Simone, P; Murtas, F; Poli Lener, M P; Bonivento, W; Cardini, A; Raspino, D; Saitta, B; Pinci, D; Baccaro, S; 10.1016/j.nuclphysbps.2005.03.054

    2006-01-01

    We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV detectors performances have been measured with X-rays and with a 3 Ge V pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in a GEM detector during a strong irradiation.

  1. Aging measurements on triple-GEM detectors operated with $CF_{4}$- based gas mixtures

    CERN Document Server

    Alfonsi, M; Bencivenni, G; Bonivento, W; Cardini, A; Lener, M P; Murtas, F; Pinci, D; Raspino, D; Saitta, B; De Simone, P

    2004-01-01

    We present the results of a global irradiation test of full size triple-GEM detectors operated with CF/sub 4/-based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV gamma from a /sup 60/Co source. After the irradiation test the detectors performances have been measured with X-rays and with a 3 GeV pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in the GEM detector during the strong irradiation.

  2. Applications of noble gas radiation detectors to counter-terrorism

    International Nuclear Information System (INIS)

    Vanier, Peter E.; Forman, Leon

    2002-01-01

    Radiation detectors are essential tools in the detection, analysis and disposition of potential terrorist devices containing hazardous radioactive and/or fissionable materials. For applications where stand-off distance and source shielding are limiting factors, large detectors have advantages over small ones. The ability to distinguish between Special Nuclear Materials and false-positive signals from natural or man-made benign sources is also important. Ionization chambers containing compressed noble gases, notably xenon and helium-3, can be scaled up to very large sizes, improving the solid angle for acceptance of radiation from a distant source. Gamma spectrometers using Xe have a factor of three better energy resolution than NaI scintillators, allowing better discrimination between radioisotopes. Xenon detectors can be constructed so as to have extremely low leakage currents, enabling them to operate for long periods of time on batteries or solar cells. They are not sensitive to fluctuations in ambient temperature, and are therefore suitable for deployment in outdoor locations. Position-sensitive 3He chambers have been built as large as 3000 cm2, and with spatial resolution of less than 1 mm. Combined with coded apertures made of cadmium, they can be used to create images of thermal neutron sources. The natural background of spallation neutrons from cosmic rays generates a very low count rate, so this instrument could be quite effective at identifying a man-made source, such as a spontaneous fission source (Pu) in contact with a moderator (high explosive)

  3. Gas Time-of-Flight Cherenkov Detector with Radiofrequency Phototube for FP420

    International Nuclear Information System (INIS)

    Margaryan, A.

    2011-01-01

    In this paper, the gas Cherenkov detector with radiofrequency phototube is considered as a fast-timing detector for FP420 project. The detector serves for precise Time-of-Flight measurements of forward going protons, capable of accurate vertex reconstruction and background rejection at high luminosities. The proposed technique is a high resolution (∼ 5 ps FWHM for a single proton), high rate (∼ MHz) and highly stable (less than 1 ps) timing technique capable to detect up to several tens events in a short (∼ 1 ns) time interval. (author)

  4. Status of /hacek C/erenkov Ring Imaging systems

    International Nuclear Information System (INIS)

    Leith, D.W.G.S.

    1987-06-01

    Cerenkov Ring Imaging is briefly introduced, and the problems or choices of designing such a counter are discussed. Recent results from the DELPHI and SLD prototype are presented and compared to the expected performances. 13 refs., 33 figs., 2 tabs

  5. Status of /hacek C/erenkov Ring Imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Leith, D.W.G.S.

    1987-06-01

    Cerenkov Ring Imaging is briefly introduced, and the problems or choices of designing such a counter are discussed. Recent results from the DELPHI and SLD prototype are presented and compared to the expected performances. 13 refs., 33 figs., 2 tabs.

  6. Analysis of calculated neutron flux response at detectors of G.A. Siwabessy multipurpose reactor (RSG-GAS Reactor)

    International Nuclear Information System (INIS)

    Taryo, Taswanda

    2002-01-01

    Multi Purpose Reactor G.A. Siwabessy (RSG-GAS) reactor core possesses 4 fission-chamber detectors to measure intermediate power level of RSG-GAS reactor. Another detector, also fission-chamber detector, is intended to measure power level of RSG-GAS reactor. To investigate influence of space to the neutron flux values for each detector measuring intermediate and power levels has been carried out. The calculation was carried out using combination of WIMS/D4 and CITATION-3D code and focused on calculation of neutron flux at different detector location of RSG-GAS typical working core various scenarios. For different scenarios, all calculation results showed that each detector, located at different location in the RSG-GAS reactor core, causes different neutron flux occurred in the reactor core due to spatial time effect

  7. Collection of a radioactive source of $^{83}$Kr to study the gas distribution dynamics in a large GRPC detector

    CERN Multimedia

    An ultra-granular hadronic calorimeter was built using Glass Resistive Plate Chamber (GRPC) detectors as the sensitive medium. The gas of those detectors of $1 \\times 1$ m$^{2}$ each is constrained to be on one side of the detector. To ensure good gas distribution a prototype was built. Such a scheme could be extended to larger GRPC detectors of more than 2 m$^{2}$ if found efficient. To check the performance a radioactive gas could be used in association with the usual gas mixture used to operate the GRPC. The distribution of the radioactive gas can be monitored thanks to the 1 cm$^2$ resolution provided by the embedded electronics used to read out the detector. The radioactive $^{83}$Kr source (obtained from $^{83}$Rb decay) could be produced at the ISOLDE facility and will be used to study larger GRPC detectors at CERN.

  8. Inverse Cerenkov laser acceleration experiment at ATF

    International Nuclear Information System (INIS)

    Wang, X.J.; Pogorelsky, I.; Fernow, R.; Kusche, K.P.; Liu, Y.; Kimura, W.D.; Kim, G.H.; Romea, R.D.; Steinhauer, L.C.

    1994-01-01

    Inverse Cerenkov laser acceleration was demonstrated using an axicon optical system at the Brookhaven Accelerator Test Facility (ATF). The ATF S-band linac and a high power 10.6 μm CO 2 laser were used for the experiment. Experimental arrangement and the laser and the electron beams synchronization are discussed. The electrons were accelerated more than 0.7 MeV for a 34 MW CO 2 laser power. More than 3.7 MeV acceleration was measured with 0.7 GW CO 2 laser power, which is more than 20 times of the previous ICA experiment. The experimental results are compared with computer program TRANSPORT simulations

  9. Determining reactor fuel elements broken by Cerenkov counting

    International Nuclear Information System (INIS)

    Guo Juhao; Dong Shiyuan; Feng Yuying

    1996-01-01

    The basis and method of determining fuel elements broken in a reactor by Cerenkov counting measured with liquid scintillation spectrometer are introduced. The radioactive characteristic of the radiation nuclides generating Cherenkov radiation in the primary water of 200 MW nuclear district heating reactor is analyzed. The activity of the activation products in the primary water and the fission products in the fuel elements are calculated. A feasibility of Cerenkov counting measure was analyzed. This method is simple and quick

  10. Electron cloud sizes in gas-filled detectors

    International Nuclear Information System (INIS)

    Boggende, A.J.F. den; Schrijver, C.J.

    1984-01-01

    Electron cloud sizes have been calculated for gas mixtures containing Ar, Xe, CO 2 , CH 4 , and N 2 for drifts through a constant electric field. The transport coefficients w and D/μ are in good agreement with experimental data of various sources for pure gases. Results of measurements, also performed in this work, for Ar+CO 2 , Ar+CH 4 , and Ar+Xe+CO 2 mixtures are in fair agreement with the calculated cloud sizes. For a large number of useful gas mixtures calculated electron cloud sizes are presented and discussed, most of which are given for the first time. A suggestion is made for an optimal gas mixture for an X-ray position sensitive proportional counter for medium and low energies. (orig.)

  11. Radiation detectors

    International Nuclear Information System (INIS)

    2013-01-01

    This sixth chapter presents the operational principles of the radiation detectors; detection using photographic emulsions; thermoluminescent detectors; gas detectors; scintillation detectors; liquid scintillation detectors; detectors using semiconductor materials; calibration of detectors; Bragg-Gray theory; measurement chain and uncertainties associated to measurements

  12. Estimating the Cerenkov neutron sensitivity of Suprasil (SiO2) and Lucite (C5H8O2)

    International Nuclear Information System (INIS)

    Clark, D.

    1982-01-01

    Fast neutrons hitting a sample of suprasil will produce light. This light is Cerenkov light produced by high energy (> .2 MeV) electrons traversing the transparent medium. Neutrons produce these electrons in a two step process. First, the neutrons inelastically scatter with either the silicon (Si) or the oxygen (O) atoms producing inelastic gamma rays. Some of these gammas, in turn, will also react producing, primarily, Compton electrons with some pair production electrons possible. The majority of these Compton electrons will have enough energy to induce Cerenkov light production. For intermediate energy neutrons (2 to 20 MeV), this process is efficient enough to produce a relatively simple neutron detector with some desirable properties. Estimations of the Cherenkov/neutron sensitivities of suprasil and lucite are presented

  13. Atmospheric pressure helium afterglow discharge detector for gas chromatography

    Science.gov (United States)

    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.

  14. Gas microstrip detectors based on flexible printed circuit

    International Nuclear Information System (INIS)

    Salomon, M.; Crowe, K.; Faszer, W.; Lindsay, P.; Curran Maier, J.M.

    1995-09-01

    We have studied the properties of a new type of Gas Microstrip Counter built using flexible printed circuit technology. We describe the manufacturing procedures, the assembly of the device, as well as its operation under a variety of conditions, gases and types of radiation. We also describe two new passivation materials, Tantalum and Niobium, which produce effective surfaces. (author)

  15. The Role of Cerenkov Radiation in the Pressure Balance of Cool Core Clusters of Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Lieu, Richard [Department of Physics, University of Alabama, Huntsville, AL 35899 (United States)

    2017-03-20

    Despite the substantial progress made recently in understanding the role of AGN feedback and associated non-thermal effects, the precise mechanism that prevents the core of some clusters of galaxies from collapsing catastrophically by radiative cooling remains unidentified. In this Letter, we demonstrate that the evolution of a cluster's cooling core, in terms of its density, temperature, and magnetic field strength, inevitably enables the plasma electrons there to quickly become Cerenkov loss dominated, with emission at the radio frequency of ≲350 Hz, and with a rate considerably exceeding free–free continuum and line emission. However, the same does not apply to the plasmas at the cluster's outskirts, which lacks such radiation. Owing to its low frequency, the radiation cannot escape, but because over the relevant scale size of a Cerenkov wavelength the energy of an electron in the gas cannot follow the Boltzmann distribution to the requisite precision to ensure reabsorption always occurs faster than stimulated emission, the emitting gas cools before it reheats. This leaves behind the radiation itself, trapped by the overlying reflective plasma, yet providing enough pressure to maintain quasi-hydrostatic equilibrium. The mass condensation then happens by Rayleigh–Taylor instability, at a rate determined by the outermost radius where Cerenkov radiation can occur. In this way, it is possible to estimate the rate at ≈2 M {sub ⊙} year{sup −1}, consistent with observational inference. Thus, the process appears to provide a natural solution to the longstanding problem of “cooling flow” in clusters; at least it offers another line of defense against cooling and collapse should gas heating by AGN feedback be inadequate in some clusters.

  16. Two-phase xenon detector with gas amplification and electroluminescent signal detection

    International Nuclear Information System (INIS)

    Akimov, D.Yu.; Burenkov, A.A.; Grishkin, Yu.L.; Kovalenko, A.G.; Lebedenko, V.N.; Stekhanov, V.N.

    2008-01-01

    An optical technique for detecting ionization electrons produced during ionization of the liquid phase has been experimentally tested in two-phase (liquid-gas) xenon. The effects of gas and electroluminescent amplifications at the wire anode are simultaneously used for detection. This method allows construction of a supersensitive detector of small ionization signals-down to those corresponding to the detection of single electrons [ru

  17. Thermoregulated Nitric Cryosystem for Cooling Gas-Filled Detectors of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Zharkov I.P.

    2015-09-01

    Full Text Available Cryosystem for cooling and filling of gas-filled detectors of ionizing radiation with compressed inert gas on the basis of wide-nitrogen cryostat, which provides detetector temperature control in a range of 173 — 293 K and its stabilization with accuracy of ± 1°. The work was carried out within the Ukraine — NATO Program of Collaboration, Grant SfP #984655.

  18. Near Detectors based on gas TPCs for neutrino long baseline experiments

    CERN Document Server

    Blondel, A

    2017-01-01

    Time Projection Chambers have been used with success for the T2K ND280 near detector and are proposed for an upgrade of the T2K near detector. High pressure TPCs are also being considered for future long-baseline experiments like Hyper-Kamiokande and DUNE. A High Pressure TPC would be a very sensitive detector for the detailed study of neutrino-nucleus interactions, a limiting factor for extracting the ultimate precision in long baseline experiments. The requirements of TPCs for neutrino detectors are quite specific. We propose here the development of state-of-the-art near detectors based on gas TPC: atmospheric pressure TPCs for T2K-II and a high-pressure TPC for neutrino experiments. The project proposed here benefits from a strong involvement of the European (CERN) members of the T2K collaboration and beyond. It is a strongly synergetic precursor of other projects of near detectors using gas TPCs that are under discussion for the long baseline neutrino projects worldwide. It will help maintain and develop...

  19. Noble Gas Leak Detector for Use in the SNS Neutron Electric Dipole Moment Experiment

    Science.gov (United States)

    Barrow, Chad; Huffman, Paul; Leung, Kent; Korobkina, Ekaterina; White, Christian; nEDM Collaboration Collaboration

    2017-09-01

    Common practice for leak-checking high vacuum systems uses helium as the probing gas. However, helium may permeate some materials at room temperature, making leak characterization difficult. The experiment to find a permanent electric dipole moment of the neutron (nEDM), to be conducted at Oak Ridge National Laboratories, will employ a large volume of liquid helium housed by such a helium-permeable composite material. It is desirable to construct a leak detector that can employ alternative test gases. The purpose of this experiment is to create a leak detector that can quantify the argon gas flux in a high vacuum environment and interpret this flux as a leak-rate. This apparatus will be used to check the nEDM volumes for leaks at room temperature before cooling down to cryogenic temperatures. Our leak detector uses a residual gas analyzer and a vacuum pumping station to characterize the gas present in an evacuated volume. The introduction of argon gas into the system is interpreted as a leak-rate into the volume. The device has been calibrated with NIST certified calibrated leaks and the machine's sensitivity has been calculated using background gas analysis. As a result of the device construction and software programming, we are able to leak-check composite and polyamide volumes This work was supported in part by the US Department of Energy under Grant No. DE-FG02-97ER41042.

  20. Gas detector with a μm size strips anode

    International Nuclear Information System (INIS)

    Oed, A.

    1988-01-01

    A flat electrode device for an ionizing radiation multidetector, particularly for an X-ray detector used in tomodensitometry, is presented. It consists of either two active electrodes of the same kind, or an anode-electrode and a cathode electrode, on opposite sides of a base plate. The device avoids problems linked to flatness and parallelism, and the base plate consists of at least two intermediate plates separated by a space containing at least layer of binding material. The device thus overcomes difficulties associated with thickness and the need to stop ionizing radiation from passing from one cell to another by traversing the base plate. The steps of the fabrication process are detailed [fr

  1. A LOW-COST GPR GAS PIPE & LEAK DETECTOR

    Energy Technology Data Exchange (ETDEWEB)

    David Cist; Alan Schutz

    2005-03-30

    A light-weight, easy to use ground penetrating radar (GPR) system for tracking metal/non-metal pipes has been developed. A pre-production prototype instrument has been developed whose production cost and ease of use should fit important market niches. It is a portable tool which is swept back and forth like a metal detector and which indicates when it goes over a target (metal, plastic, concrete, etc.) and how deep it is. The innovation of real time target detection frees the user from having to interpret geophysical data and instead presents targets as dots on the screen. Target depth is also interpreted automatically, relieving the user of having to do migration analysis. In this way the user can simply walk around looking for targets and, by ''connecting the dots'' on the GPS screen, locate and follow pipes in real time. This is the first tool known to locate metal and non-metal pipes in real time and map their location. This prototype design is similar to a metal detector one might use at the beach since it involves sliding a lightweight antenna back and forth over the ground surface. The antenna is affixed to the end of an extension that is either clipped to or held by the user. This allows him to walk around in any direction, either looking for or following pipes with the antenna location being constantly recorded by the positioning system. Once a target appears on the screen, the user can locate by swinging the unit to align the cursor over the dot. Leak detection was also a central part of this project, and although much effort was invested into its development, conclusive results are not available at the time of the writing of this document. Details of the efforts that were made as a part of this cooperative agreement are presented.

  2. Development and characterization of micro-pattern gas detectors for intense beams of hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Vandenbroucke, Maxence

    2012-07-02

    This thesis work is dedicated to the design, development and characterization of Micro-Pattern Gas Detectors. The performances of a Time Projection Chamber (TPC) equipped with a triple Gas Electron Multiplier (GEM) amplification structure are reported. The intrinsic ion backflow suppression of GEM foils drastically reduces the space charge produced by wire readout in traditional TPC. The GEM solution allows the operation of a TPC at much higher event rate. The second part of this thesis describes the development of a 40 x 40 cm{sup 2} Micromegas detector with a highly segmented central area. A reduction of discharges compared to conventional Micromegas detectors is needed for stable operation in intense beams of hadrons. Spark reduction technologies have been successfully studied and results are presented.

  3. Design of a readout ASIC for gas detectors with self-amplification

    International Nuclear Information System (INIS)

    Deng Zhi; Liu Yinong

    2009-01-01

    A readout ASIC has been designed for gas detectors with self-amplification such as GEM and RPC. It provides amplification and shaping of the detector signals and buffers them to the free running ADCs. The charge gain and the shaping time can be adjusted. The programmability of gain and shaping time is very convenient for studying detector performance under different gas gain and also expands the application range of the chip. The ENC increases as charge gain decreases below 10 mV/fC because the noise from the shaper becomes significant. The chip is designed in Chartered 0.35μm 2P4M CMOS process. Detailed design and simulation results are described in the paper. (authors)

  4. A gas proportional scintillation counter for use in large area detector systems without photomultipliers

    International Nuclear Information System (INIS)

    Baruch, J.E.F.; Brooke, G.; Kellerman, E.W.; Bateman, J.E.; Connolly, J.F.

    1979-01-01

    The properties of a prototype gas proportional scintillation (GPS) detector module are described. The module (25X25X14cm 3 ) is intended to form the basic unit of large area (up to approximately 100 m 2 ) calorimetric cosmic ray burst detector. Ionisation from particle tracks in the module is collected onto a point electrode where the GPS signal is generated. A concave mirror focusses this point source onto the end of a fibre optic light guide. In the proposed large area detector these fibres are brought together onto a low light level TV camera which performs the readout. The prototype module has demonstrated an adequate light output for the detection of single muons by such a readout system and also permitted the investigation of the main operating parameters (gas mixture, EHT, pressure, etc) and operational requirements such as proportionality and long term stability. (Auth.)

  5. Development and characterization of micro-pattern gas detectors for intense beams of hadrons

    International Nuclear Information System (INIS)

    Vandenbroucke, Maxence

    2012-01-01

    This thesis work is dedicated to the design, development and characterization of Micro-Pattern Gas Detectors. The performances of a Time Projection Chamber (TPC) equipped with a triple Gas Electron Multiplier (GEM) amplification structure are reported. The intrinsic ion backflow suppression of GEM foils drastically reduces the space charge produced by wire readout in traditional TPC. The GEM solution allows the operation of a TPC at much higher event rate. The second part of this thesis describes the development of a 40 x 40 cm 2 Micromegas detector with a highly segmented central area. A reduction of discharges compared to conventional Micromegas detectors is needed for stable operation in intense beams of hadrons. Spark reduction technologies have been successfully studied and results are presented.

  6. Comparative measurements of soil gas radon concentration using thermoluminescent and track detectors

    Czech Academy of Sciences Publication Activity Database

    Turek, Karel; Gelev, M.; Dimov, I.

    2004-01-01

    Roč. 38, spec. iss. (2004), s. 843-846 ISSN 1350-4487 Institutional research plan: CEZ:AV0Z1048901 Keywords : soil gas * radon concentration * thermoluminescent detectors Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.664, year: 2004

  7. Online gas analysis and diagnosis for RPC detectors in the ATLAS experiment

    International Nuclear Information System (INIS)

    De Asmundis, Riccardo

    2007-01-01

    Resistive Plate Counters (RPC) detectors need a very strict control of gas parameters: motivations for this statement come from both the request of stability in the detector working point, and chemical consideration concerning potentially aggressive materials generated during the ionization processes into the sensitive gap; the latter point can be relevant because of a possible damage to the internal surface of the detector that has to be avoided in order to ensure an high detection efficiency of the RPC during their ten years or more of operation in ATLAS. In order to understand these aspects, detailed studies on gas behavior have been carried on at the GIF-X5 at CERN (2002-2005), based on Gas Chromatographic and spectroscopy techniques. Main results of these analysis are presented here, together with the design of the online analyzer to be installed on ATLAS conceived to keep control of gas quality and to trigger maintenance interventions on the gas system, in particular on the purification subsystem

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

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, T., E-mail: fujiwara-t@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Mitsuya, Y. [Nuclear Professional School, The University of Tokyo, Tokai, Naka, Ibaraki 319-1188 (Japan); Fushie, T. [Radiment Lab. Inc., Setagaya, Tokyo 156-0044 (Japan); Murata, K.; Kawamura, A.; Koishikawa, A. [XIT Co., Naruse, Machida, Tokyo 194-0045 (Japan); Toyokawa, H. [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Takahashi, H. [Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8654 (Japan)

    2017-04-01

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

  9. The DosiMap, a new 2D scintillating dosimeter for IMRT quality assurance: Characterization of two Cerenkov discrimination methods

    International Nuclear Information System (INIS)

    Frelin, A-M.; Fontbonne, J-M.; Ban, G.; Colin, J.; Labalme, M.; Batalla, A.; Vela, A.; Boher, P.; Braud, M.; Leroux, T.

    2008-01-01

    New radiation therapy techniques such as IMRT present significant efficiency due to their highly conformal dose distributions. A consequence of the complexity of their dose distributions (high gradients, small irradiation fields, low dose distribution, ...) is the requirement for better precision quality assurance than in classical radiotherapy in order to compare the conformation of the delivered dose with the planned dose distribution and to guarantee the quality of the treatment. Currently this control is mostly performed by matrices of ionization chambers, diode detectors, dosimetric films, portal imaging, or dosimetric gels. Another approach is scintillation dosimetry, which has been developed in the last 15 years mainly through scintillating fiber devices. Despite having many advantages over other methods it is still at an experimental level for routine dosimetry because the Cerenkov radiation produced under irradiation represents an important stem effect. A new 2D water equivalent scintillating dosimeter, the DosiMap, and two different Cerenkov discrimination methods were developed with the collaboration of the Laboratoire de Physique Corpusculaire of Caen, the Comprehensive Cancer Center Francois Baclesse, and the ELDIM Co., in the frame of the MAESTRO European project. The DosiMap consists of a plastic scintillating sheet placed inside a transparent polystyrene phantom. The light distribution produced under irradiation is recorded by a CCD camera. Our first Cerenkov discrimination technique is subtractive. It uses a chessboard pattern placed in front of the scintillator, which provides a background signal containing only Cerenkov light. Our second discrimination technique is colorimetric. It performs a spectral analysis of the light signal, which allows the unfolding of the Cerenkov radiation and the scintillation. Tests were carried out with our DosiMap prototype and the performances of the two discrimination methods were assessed. The comparison of the

  10. The DosiMap, a new 2D scintillating dosimeter for IMRT quality assurance: characterization of two Cerenkov discrimination methods.

    Science.gov (United States)

    Frelin, A M; Fontbonne, J M; Ban, G; Colin, J; Labalme, M; Batalla, A; Vela, A; Boher, P; Braud, M; Leroux, T

    2008-05-01

    New radiation therapy techniques such as IMRT present significant efficiency due to their highly conformal dose distributions. A consequence of the complexity of their dose distributions (high gradients, small irradiation fields, low dose distribution, ...) is the requirement for better precision quality assurance than in classical radiotherapy in order to compare the conformation of the delivered dose with the planned dose distribution and to guarantee the quality of the treatment. Currently this control is mostly performed by matrices of ionization chambers, diode detectors, dosimetric films, portal imaging, or dosimetric gels. Another approach is scintillation dosimetry, which has been developed in the last 15 years mainly through scintillating fiber devices. Despite having many advantages over other methods it is still at an experimental level for routine dosimetry because the Cerenkov radiation produced under irradiation represents an important stem effect. A new 2D water equivalent scintillating dosimeter, the DosiMap, and two different Cerenkov discrimination methods were developed with the collaboration of the Laboratoire de Physique Corpusculaire of Caen, the Comprehensive Cancer Center François Baclesse, and the ELDIM Co., in the frame of the MAESTRO European project. The DosiMap consists of a plastic scintillating sheet placed inside a transparent polystyrene phantom. The light distribution produced under irradiation is recorded by a CCD camera. Our first Cerenkov discrimination technique is subtractive. It uses a chessboard pattern placed in front of the scintillator, which provides a background signal containing only Cerenkov light. Our second discrimination technique is colorimetric. It performs a spectral analysis of the light signal, which allows the unfolding of the Cerenkov radiation and the scintillation. Tests were carried out with our DosiMap prototype and the performances of the two discrimination methods were assessed. The comparison of the

  11. The utilisation of two detectors for the determination of water in honey using headspace gas chromatography.

    Science.gov (United States)

    Frink, Lillian A; Armstrong, Daniel W

    2016-08-15

    A headspace gas chromatography (HSGC) method was developed for the determination of water content in honey. This method was shown to work with five different honey varieties which had a range of water from 14-16%. It also utilised two different detectors, the thermal conductivity detector (TCD) and the barrier discharge ionisation detector (BID). This method needs no heating pretreatment step as in the current leading method, (i.e. the measurement of refractive index). The solvent-free procedure negates the possibility of solvent-compound interactions as well as solubility limitations, as is common with Karl Fischer titrations. It was also apparent that the classic loss on drying method consistently and substantially produced results that were lower than the correct values. This approach is shown to be rapid, with an analysis time of 4 min when using the TCD detector and under 3 min when utilising the BID detector. HSGC is feasible for the determination of water due to the new PEG-linked geminal dicationic ionic-liquid-coated GC capillary column. In addition it provides accurate and precise determinations of the water content in honey. When using the sensitive BID detector, other trace volatile compounds are observed as well. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Energy and resolution calibration of detectors for noble gas β-γ coincidence system

    International Nuclear Information System (INIS)

    Jia Huaimao; Wang Shilian; Li Qi; Wang Jun; Zhao Yungang; Zhang Xinjun; Fan Yuanqing

    2010-01-01

    The β-γ coincidence technique is a kind of important method to detect radioactive xenon isotopes for the Comprehensive Nuclear-Test-Ban Treaty(CTBT). The energy and resolution calibration of detectors is the first key technique. This paper describes in detail the energy and resolution calibration methods of NaI (Tl) and plastic scintillator detectors for the noble gas β-γ coincidence system SAUNA II-Lab. NaI (Tl) detector's energy and resolution for γ-ray were calibrated with γ radioactive point sources. Plastic scintillator detector's energy and resolution for β-ray were calibrated by Compton scattering electrons of 137 Cs 661.66 keV γ-ray. And the results of β-ray energy resolution calibrated by Compton scattering electrons of 137 Cs were compared with the results of conversion electron of 131 Xe m . In conclusion,it is an easy and feasible method of calibrating plastic scintillator detector's energy by Compton scattering electrons of 137 Cs,but detector's resolution calibrated by Compton scattering electrons is higher than factual result. (authors)

  13. Recent developments and applications of fast position-sensitive gas detectors

    International Nuclear Information System (INIS)

    Sauli, Fabio

    1999-01-01

    The introduction, 30 years ago, of the multiwire proportional chamber initiated a very active and fruitful period of development of fast gas detectors. Performing position-sensitive devices have been perfected, for the needs of elementary particle physics and for applications in medical diagnostics, biology, material analysis. The high rate performance of wire counters, limited by positive ions accumulation, was largely improved with the introduction of the micro-strip gas chamber, capable of achieving position accuracies of few tens of microns at radiation fluxes exceeding 1 MHz/mm 2 . The micro-strip chamber properties have been extensively studied in view of large scale use in high luminosity experiments; some interesting applications in other fields will be described here. Originally conceived as a gain booster to solve reliability problems met with micro-strips, the gas electron multiplier was invented about a year and a half ago. Progress made with high gain models is leading to a new concept in gas detectors, powerful yet cheap and reliable. Possible developments and applications will be discussed: large area position-sensitive photo detectors and X-ray imagers, including devices with non-planar geometry suited to spectrometers and crystal diffraction studies

  14. Hybrid model based unified scheme for endoscopic Cerenkov and radio-luminescence tomography: Simulation demonstration

    Science.gov (United States)

    Wang, Lin; Cao, Xin; Ren, Qingyun; Chen, Xueli; He, Xiaowei

    2018-05-01

    Cerenkov luminescence imaging (CLI) is an imaging method that uses an optical imaging scheme to probe a radioactive tracer. Application of CLI with clinically approved radioactive tracers has opened an opportunity for translating optical imaging from preclinical to clinical applications. Such translation was further improved by developing an endoscopic CLI system. However, two-dimensional endoscopic imaging cannot identify accurate depth and obtain quantitative information. Here, we present an imaging scheme to retrieve the depth and quantitative information from endoscopic Cerenkov luminescence tomography, which can also be applied for endoscopic radio-luminescence tomography. In the scheme, we first constructed a physical model for image collection, and then a mathematical model for characterizing the luminescent light propagation from tracer to the endoscopic detector. The mathematical model is a hybrid light transport model combined with the 3rd order simplified spherical harmonics approximation, diffusion, and radiosity equations to warrant accuracy and speed. The mathematical model integrates finite element discretization, regularization, and primal-dual interior-point optimization to retrieve the depth and the quantitative information of the tracer. A heterogeneous-geometry-based numerical simulation was used to explore the feasibility of the unified scheme, which demonstrated that it can provide a satisfactory balance between imaging accuracy and computational burden.

  15. A monolithically fabricated gas chromatography separation column with an integrated high sensitivity thermal conductivity detector

    International Nuclear Information System (INIS)

    Kaanta, Bradley C; Zhang, Xin; Chen, Hua

    2010-01-01

    The monolithic integration of a high sensitivity detector with a gas chromatography (GC) separation column creates many potential advantages over the discrete components of a traditional chromatography system. In miniaturized high-speed GC systems, component interconnections can cause crucial errors and loss of fidelity during detection and analysis. A monolithically integrated device would eliminate the need to create helium-tight interconnections, which are bulky and labor intensive. Additionally, batch fabrication of integrated devices that no longer require expensive and fragile detectors can decrease the cost of micro GC systems through economies of scale. We present the design, fabrication and operation of a monolithic GC separation column and detector. Our device is able to separate nitrogen, methane and carbon dioxide within 30 s. This method of device integration could be applied to the existing wealth of column geometries and chemistries designed for specialized applications.

  16. Analysis for In-situ Fission Rate Measurements using 4He Gas Scintillation Detectors

    International Nuclear Information System (INIS)

    Lewis, Jason M.; Raetz, Dominik; Jordan, Kelly A.; Murer, David

    2013-06-01

    Active neutron interrogation is a powerful NDA technique that relies on detecting and analyzing fission neutrons produced in a fuel sample by an interrogating high neutron flux. 4 He scintillation gas fast neutron detectors are investigated in this paper for use in a novel fission rate measurement technique The He-4 detectors have excellent gamma rejection, a fast response time, and give significant information on incident neutron energy allowing for energy cuts to be applied to the detected signal. These features are shown in this work to allow for the detection of prompt fission neutrons in-situ during active neutron interrogation of a 238 U sample. The energy spectrum from three different neutrons sources ( 252 Cf, AmBe, AmLi) is measured using the 4 He detection system and analyzed. An initial response matrix for the detector is determined using these measurements and the kinematic interaction properties of the elastic scattering with the 4 He. (authors)

  17. Harsh-Environment Solid-State Gamma Detector for Down-hole Gas and Oil Exploration

    International Nuclear Information System (INIS)

    Peter Sandvik; Stanislav Soloviev; Emad Andarawis; Ho-Young Cha; Jim Rose; Kevin Durocher; Robert Lyons; Bob Pieciuk; Jim Williams; David O'Connor

    2007-01-01

    The goal of this program was to develop a revolutionary solid-state gamma-ray detector suitable for use in down-hole gas and oil exploration. This advanced detector would employ wide-bandgap semiconductor technology to extend the gamma sensor's temperature capability up to 200 C as well as extended reliability, which significantly exceeds current designs based on photomultiplier tubes. In Phase II, project tasks were focused on optimization of the final APD design, growing and characterizing the full scintillator crystals of the selected composition, arranging the APD device packaging, developing the needed optical coupling between scintillator and APD, and characterizing the combined elements as a full detector system preparing for commercialization. What follows is a summary report from the second 18-month phase of this program

  18. Harsh-Environment Solid-State Gamma Detector for Down-hole Gas and Oil Exploration

    Energy Technology Data Exchange (ETDEWEB)

    Peter Sandvik; Stanislav Soloviev; Emad Andarawis; Ho-Young Cha; Jim Rose; Kevin Durocher; Robert Lyons; Bob Pieciuk; Jim Williams; David O' Connor

    2007-08-10

    The goal of this program was to develop a revolutionary solid-state gamma-ray detector suitable for use in down-hole gas and oil exploration. This advanced detector would employ wide-bandgap semiconductor technology to extend the gamma sensor's temperature capability up to 200 C as well as extended reliability, which significantly exceeds current designs based on photomultiplier tubes. In Phase II, project tasks were focused on optimization of the final APD design, growing and characterizing the full scintillator crystals of the selected composition, arranging the APD device packaging, developing the needed optical coupling between scintillator and APD, and characterizing the combined elements as a full detector system preparing for commercialization. What follows is a summary report from the second 18-month phase of this program.

  19. arXiv Simulation of gain stability of THGEM gas-avalanche particle detectors

    CERN Document Server

    Correia, P.M.M.; Azevedo, C.D.R.; Breskin, A.; Bressler, S.; Oliveira, C.A.B.; Silva, A.L.M.; Veenhof, R.; Veloso, J.F.C.A.

    2018-01-19

    Charging-up processes affecting gain stability in Thick Gas Electron Multipliers (THGEM) were studied with a dedicated simulation toolkit. Integrated with Garfield++, it provides an effective platform for systematic phenomenological studies of charging-up processes in MPGD detectors. We describe the simulation tool and the fine-tuning of the step-size required for the algorithm convergence, in relation to physical parameters. Simulation results of gain stability over time in THGEM detectors are presented, exploring the role of electrode-thickness and applied voltage on its evolution. The results show that the total amount of irradiated charge through electrode's hole needed for reaching gain stabilization is in the range of tens to hundreds of pC, depending on the detector geometry and operational voltage. These results are in agreement with experimental observations presented previously.

  20. Study of a microstrip gas detector for the Compact Muon Solenoid experiment

    International Nuclear Information System (INIS)

    Clergeau, J. F.

    1997-01-01

    The micro-strip gas chambers (MSGC) were realized due to the technological advances in the field of micro-electronics. The wire of usual gas counters is replaced in these detectors by metallic stripes as a periodic sequence of electrodes (anodes and cathodes) spaced by around 200 μm. At a distance of 3 mm above the strip containing substrate, a metallic plane is placed, thus defining the gaseous room where the passage of a charged particle produces by ionization a primary electron signal collected by the detector anodes. Due to its granularity a MSGC can operate under very high particle fluxes since charge can be collected very rapidly. Also, the impact parameters can be determined with high accuracy due to the high space and time resolutions. The Compact Muon Solenoid (CMS) or the MSGC detectors planned to equip one of the experiments proposed for LHC should detect, in extreme operational conditions, the particle impacts in a 4 Tesla magnetic field, for around ten years and for a particle flux of around 10 4 Hz/mm 2 . The CMS detector is described in chapter 2. The operation principle and the problems encountered in the development of MSGC detectors are summarized in chapter 3. The chapter 4 is dedicated to the study of the performances of MSGCs in magnetic fields. In the chapters 5 to 7 the processing of the signal from detectors of this type is described, particularly, the performances of various ways of treat the signal in terms of detection efficiency and counting loads are presented.The chapter 8 presents the results obtained with the prototype obtained at IPNL while the chapter 9 gives the conclusions of the performed works. (author)

  1. Design and Characterization of the VMM1 ASIC for Micropattern Gas Detectors

    CERN Document Server

    Metcalfe, J; The ATLAS collaboration; Fried, J; Li, S; Nambiar, N; Polychronakos, V; Vernon, E

    2013-01-01

    We present here the measurements of the first prototype VMM1 ASIC designed at Brookhaven National Laboratory in 130 nm CMOS and fabricated in spring 2012. The 64-channel ASIC features a novel design for use with several types of micropattern gas detectors. The data driven system measures peak amplitude and timing information in tracking mode and first channel hit address in trigger mode. Several programmable gain and integration times allows the flexibility to work with Micromegas, Thin Gap Chambers (TGCs), and Gas Electron Multiplier (GEM) detectors. The IC design architecture and features will be presented along with measurements characterizing the performance of the VMM1 such as noise, linearity of the response, time walk, and calibration range. The concept for use with Micromegas in ATLAS Upgrade will also be covered including characterization under test beam conditions.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fatherley, V. E., E-mail: vef@lanl.gov; Bingham, D. A.; Cartelli, M. D.; Griego, J. R.; Herrmann, H. W.; Lopez, F. E.; Oertel, J. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); DiDomizio, R. A.; Pollack, M. J. [EnvirOptics, Inc., Colmar, Pennsylvania 18915 (United States)

    2016-11-15

    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.

  3. Image simulation of high-speed imaging by high-pressure gas ionization detector

    International Nuclear Information System (INIS)

    Miao Jichen; Liu Ximing; Wu Zhifang

    2005-01-01

    The signal of the neighbor pixels is cumulated in Freight Train Inspection System because data fetch time is shorter than ion excursion time. This paper analyzes the pertinency of neighbor pixels and designs computer simulation method to generate some emulate images such as indicator image. The result indicates the high-pressure gas ionization detector can be used in high-speed digital radiography field. (authors)

  4. Multi-detector system approach for unattended uranium enrichment monitoring at gas centrifuge enrichment plants

    Science.gov (United States)

    Favalli, A.; Lombardi, M.; MacArthur, D. W.; McCluskey, C.; Moss, C. E.; Paffett, M. T.; Ianakiev, K. D.

    2018-01-01

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants while reducing the inspection effort is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One requirement of such a monitor is a simple, reliable and precise passive measurement of the 186-keV line from 235U. The other information required is the amount of gas in the pipe, which can be obtained by a transmission or pressure measurement. We describe our research to develop such a passive measurement system. Unfortunately, a complication arises in the interpretation of the gamma measurements, from the contribution of uranium deposits on the wall of the pipe to the 186-keV peak. A multi-detector approach to address this complication is presented where two measurements, one with signal primarily from gas and one with signal primarily from deposits, are performed simultaneously with different detectors and geometries. This allows a correction to be made to the 186-keV peak for the contribution from the deposit. We present the design of the multi-detector system and the results of the experimental calibration of the proof-of-principle prototype built at LANL.

  5. Determination of tolerances of mirror displacement and radiator gas impurity for the CBM RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Adamczewski-Musch, J. [GSI Darmstadt (Germany); Becker, K.-H. [University Wuppertal (Germany); Belogurov, S. [ITEP Moscow (Russian Federation); Boldyreva, N. [PNPI Gatchina (Russian Federation); Chernogorov, A. [ITEP Moscow (Russian Federation); Deveaux, C. [University Gießen (Germany); Dobyrn, V. [PNPI Gatchina (Russian Federation); Dürr, M. [University Gießen (Germany); Eom, J. [Pusan National University (Korea, Republic of); Eschke, J. [GSI Darmstadt (Germany); Höhne, C. [University Gießen (Germany); Kampert, K.-H. [University Wuppertal (Germany); Kleipa, V. [GSI Darmstadt (Germany); Kochenda, L. [PNPI Gatchina (Russian Federation); Kolb, B. [GSI Darmstadt (Germany); Kopfer, J. [University Wuppertal (Germany); Kravtsov, P. [PNPI Gatchina (Russian Federation); Lebedev, S.; Lebedeva, E. [University Gießen (Germany); Leonova, E. [PNPI Gatchina (Russian Federation); and others

    2014-12-01

    The CBM experiment at the future FAIR facility will explore nuclear matter at high net-baryon densities. One of the key observables is di-leptons as they penetrate the created matter without further strong interactions. A gaseous RICH detector in a standard projective geometry using spherical mirrors is one of two detector elements for the required electron identification. The mirror system consists of about 72 trapezoidal mirror tiles. Any misalignment between the tiles relative to the nominal common spherical surface leads to reduction of the reconstruction efficiency of Cherenkov rings and deterioration of their resolution. To determine tolerances in mirror misalignment extensive simulation and measurement studies were carried out. Pure CO{sub 2} will be used as radiator gas. Gas contamination, mainly moisture and Oxygen, reduces the number of detected photons per ring and worsens the quality of reconstructed Cherenkov rings. Therefore a study was carried out to determine tolerances in radiator gas contamination. - Highlights: • Mirror misalignment leads to ring deformation in a RICH detector. • Radiator contamination leads to resolution deterioration of fitted rings. • To determine tolerances measurements and simulations were carried out. • Mirror displacements of up to 0.32 mm at any mirror side can be tolerated. • Oxygen (moisture) contamination of up to 1% (0.0011%) can be safely tolerated.

  6. Multi-detector system approach for unattended uranium enrichment monitoring at gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Favalli, A.; Lombardi, M.; MacArthur, D. W.; McCluskey, C.; Moss, C. E.

    2017-01-01

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants while reducing the inspection effort is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One requirement of such a monitor is a simple, reliable and precise passive measurement of the 186-keV line from 235 U. The other information required is the amount of gas in the pipe, which can be obtained by a transmission or pressure measurement. Here, we describe our research to develop such a passive measurement system. Unfortunately, a complication arises in the interpretation of the gamma measurements, from the contribution of uranium deposits on the wall of the pipe to the 186-keV peak. A multi-detector approach to address this complication is presented where two measurements, one with signal primarily from gas and one with signal primarily from deposits, are performed simultaneously with different detectors and geometries. This allows a correction to be made to the 186-keV peak for the contribution from the deposit. Finally, we present the design of the multi-detector system and the results of the experimental calibration of the proof-of-principle prototype built at LANL.

  7. Measurement of Odor-Plume Structure in a Wind Tunnel Using a Photoionization Detector and a Tracer Gas

    National Research Council Canada - National Science Library

    Justus, Kristine

    2002-01-01

    The patterns of stimulus available to moths flying along pheromone plumes in a 3-m-long wind tunnel were characterized using a high frequency photoionization detector in conjunction with an inert tracer gas...

  8. The radiation gas detectors with novel nanoporous converter for medical imaging applications

    Science.gov (United States)

    Zarei, H.; Saramad, S.

    2018-02-01

    For many reason it is tried to improve the quantum efficiency (QE) of position sensitive gas detectors. For energetic X-rays, the imaging systems usually consist of a bulk converter and gas amplification region. But the bulk converters have their own limitation. For X-rays, the converter thickness should be increased to achieve a greater detection efficiency, however in this case, the chance of escaping the photoelectrons is reduced. To overcome this limitation, a new type of converter, called a nanoporous converter such as Anodizing Aluminum Oxide (AAO) membrane with higher surface to volume ratio is proposed. According to simulation results with GATE code, for this nanoporous converter with the 1 mm thickness and inter pore distance of 627 nm, for 20-100 keV X-ray energies with a reasonable gas pressure and different pore diameters, the QE can be one order of magnitude greater than the bulk ones, which is a new approach for proposing high QE position sensitive gas detectors for medical imaging application and also high energy physics.

  9. Method for monitoring irradiated nuclear fuel using cerenkov radiation

    International Nuclear Information System (INIS)

    Caldwell, J.T.; Dowdy, E.J.; Nicholson, N.

    1983-01-01

    A method is provided for monitoring irradiated nuclear fuel inventories located in a water-filled storage pond wherein the intensity of the cerenkov radiation emitted from the water in the vicinity of the nuclear fuel is measured. This intensity is then compared with the expected intensity for nuclear fuel having a corresponding degree of irradiation exposure and time period after removal from a reactor core. Where the nuclear fuel inventory is located in an assembly having fuel pins or rods with intervening voids, the cerenkov light intensity measurement is taken at selected bright spots corresponding to the water-filled interstices of the assembly in the water storage, the waterfilled interstices acting as cerenkov light channels so as to reduce cross-talk. On-line digital analysis of an analog video signal is possible, or video tapes may be used for later measurement using a video editor and an electrometer. Direct measurement of the cerenkov radiation intensity also is possible using spot photometers pointed at the assembly

  10. On the elimination of numerical Cerenkov radiation in PIC simulations

    International Nuclear Information System (INIS)

    Greenwood, Andrew D.; Cartwright, Keith L.; Luginsland, John W.; Baca, Ernest A.

    2004-01-01

    Particle-in-cell (PIC) simulations are a useful tool in modeling plasma in physical devices. The Yee finite difference time domain (FDTD) method is commonly used in PIC simulations to model the electromagnetic fields. However, in the Yee FDTD method, poorly resolved waves at frequencies near the cut off frequency of the grid travel slower than the physical speed of light. These slowly traveling, poorly resolved waves are not a problem in many simulations because the physics of interest are at much lower frequencies. However, when high energy particles are present, the particles may travel faster than the numerical speed of their own radiation, leading to non-physical, numerical Cerenkov radiation. Due to non-linear interaction between the particles and the fields, the numerical Cerenkov radiation couples into the frequency band of physical interest and corrupts the PIC simulation. There are two methods of mitigating the effects of the numerical Cerenkov radiation. The computational stencil used to approximate the curl operator can be altered to improve the high frequency physics, or a filtering scheme can be introduced to attenuate the waves that cause the numerical Cerenkov radiation. Altering the computational stencil is more physically accurate but is difficult to implement while maintaining charge conservation in the code. Thus, filtering is more commonly used. Two previously published filters by Godfrey and Friedman are analyzed and compared to ideally desired filter properties

  11. A fast VUV light pulser for testing ring-imaging Cerenkov counters

    International Nuclear Information System (INIS)

    Margulies, S.; Ozelis, J.

    1986-01-01

    A simple, fast, VUV light pulser for testing a TMAE-based, time-projection-chamber-type photon detector for a ring-imaging Cerenkov counter is described. The pulser consists of an automobile spark plug fired in a controlled atmosphere by a relaxation oscillator. The resulting VUV spectrum, spark-current pulse, and light pulse were investigated for hydrogen, xenon, krypton, and nitrogen fills. The best pulse (3.5 ns FWHM) was obtained with hydrogen at 60 kPa absolute pressure. Xenon was, generally, unsuitable because it continued to emit light for more than a microsecond after excitation. With krypton and nitrogen, no light was emitted in the wavelength region of interest except for a series of sharp lines attributable to the electrodes

  12. Development of an in situ calibration technique for combustible gas detectors

    Science.gov (United States)

    Shumar, J. W.; Wynveen, R. A.; Lance, N., Jr.; Lantz, J. B.

    1977-01-01

    This paper describes the development of an in situ calibration procedure for combustible gas detectors (CGD). The CGD will be a necessary device for future space vehicles as many subsystems in the Environmental Control/Life Support System utilize or produce hydrogen (H2) gas. Existing calibration techniques are time-consuming and require support equipment such as an environmental chamber and calibration gas supply. The in situ calibration procedure involves utilization of a water vapor electrolysis cell for the automatic in situ generation of a H2/air calibration mixture within the flame arrestor of the CGD. The development effort concluded with the successful demonstration of in situ span calibrations of a CGD.

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

    Science.gov (United States)

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

    2017-02-01

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

  14. The development of a gas-filled time-of-flight detector

    International Nuclear Information System (INIS)

    Guan Yongjing; He Ming; Ruan Xiangdong; Wang Huijuan; Wu Shaoyong; Dong Kejun; Lin Min; Yuan Jian; Jiang Shan

    2007-01-01

    A gas-filled time-of-flight (GF-TOF) detector system for isobaric identification has been developed at the AMS facility of the China Institute of Atomic Energy (CIAE). The newly built GF-TOF detector was tested by using a 36 Cl standard sample ( 36 Cl/Cl = 2.88 x 10 -11 ) with the 36 Cl ion energies of 64, 49 and 33 MeV. Time resolutions of 350 ps, 580 ps and 920 ps were obtained for 64, 49 and 33 MeV 36 S, respectively, without gas. 36 Cl and 36 S particles were successfully separated in the TOF spectra from the GF-TOF detector at the three different incident energies. The dependence of time resolution and separation power of GF-TOF method on the incidence energy and the residual energy is discussed. The comparison of separation power for isobars between the GF-TOF method and the ΔE-E method is described. A combination of GF-TOF method and ΔE-E method may further improve the separation power for isobars. The results show that the sensitivity for 36 Cl AMS measurements is 10 -14 at the energy of 33 MeV. Some results obtained with the GF-TOF method are given

  15. A gas ionisation Direct-STIM detector for MeV ion microscopy

    International Nuclear Information System (INIS)

    Norarat, Rattanaporn; Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef; Roux, Adrien; Stoppini, Luc; Whitlow, Harry J.

    2015-01-01

    Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Müller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors (e.g. proton induced fluorescence). Here we report the performance for imaging ReNcells VM with μm resolution where energy resolutions of <24 keV fwhm could be achieved for 1 MeV protons using isobutane gas

  16. The ALTRO Chip A 16-channel A/D Converter and Digital Processor for Gas Detectors

    CERN Document Server

    Esteve-Bosch, R; Mota, B; Musa, L

    2003-01-01

    The ALTRO (ALICE TPC Read Out) chip is a mixed-signal integrated circuit designed to be one of the building blocks of the readout electronics for gas detectors. Originally conceived and optimised for the Time Projection Chamber (TPC) of the ALICE experiment at the CERN LHC, its architecture and programmability makes it suitable for the readout of a wider class of gas detectors. In one single chip, the analogue signals from 16 channels are digitised, processed, compressed and stored in a multi-acquisition memory. The Analogue-to- Digital converters embedded in the chip have a 10-bit dynamic range and a maximum sampling rate in the range of 20 to 40MHz. After digitisation, a pipelined hardwired Processor is able to remove from the input signal a wide range of systematic and non-systematic perturbations, related to the non-ideal behaviour of the detector, temperature variation of the electronics, environmental noise, etc. Moreover, the Processor is able to suppress the signal tail within 1mus after the pulse pea...

  17. Gas support systems for hadronic high-rate detectors The example of the Inner Tracker of HERA-B

    CERN Document Server

    Dreis, H B

    2003-01-01

    The challenge to avoid aging in the new generation of hadronic high- rate detectors at DESY and CERN requires that new and higher standards for material quality and cleanliness be maintained, not only for the new detectors but also for the gas support systems. The effort that is necessary to test materials for detectors must also be extended to all parts of the system that come into contact with the gas. These detailed and critical investigations must also include the traditional materials and equipment that have been used up to now without any problems. It appears that a number of parts contain outgassing material, which has been negligible so far, but can cause fast aging under high-rate conditions. In addition, quenchers in these conditions can become chemically reactive and limit the number of usable gas system components even further. The gas systems for HERA-B fulfill those requirements, and the Inner Tracker gas system is presented as an example.

  18. Dissociative electron attachment negative ion mass spectrometry: a chlorine-specific detector for gas chromatography

    Science.gov (United States)

    Curtis, Jonathan M.; Boyd, Robert K.

    1997-11-01

    This work describes the application of negative ion chemical ionization, optimized for dissociative electron attachment (DEA), to location of unknown trace chlorinated compounds in complex gas chromatograms by selected ion recording (SIR) of m / z 35 and 37. The DEA-SIR technique is compared with other GC detectors, including the electron capture detector, electrolytic conductivity detector, the atomic emission detector and the chemical reaction interface mass spectrometry method, with respect to selectivity for chlorine, sensitivity, linear dynamic range, and general robustness and ease of use. When applied to quantitative analysis of target analytes such as polychlorobiphenyls, the DEA-SIR method has potential problems arising from the possibility of suppression effects due to abundant co-eluting components, and possible alleviating measures are discussed. In addition to these practical investigations, literature information on the fundamental physical and chemical phenomena underlying the DEA process is summarized in order to guide future work on extension to other compound types and on general improvements to the technique.

  19. Amperometric detector for gas chromatography based on a silica sol-gel solid electrolyte.

    Science.gov (United States)

    Steinecker, William H; Miecznikowski, Krzysztof; Kulesza, Pawel J; Sandlin, Zechariah D; Cox, James A

    2017-11-01

    An electrochemical cell comprising a silica sol-gel solid electrolyte, a working electrode that protrudes into a gas phase, and reference and counter electrodes that contact the solid electrolyte comprises an amperometric detector for gas chromatography. Under potentiostatic conditions, a current related to the concentration of an analyte in the gas phase is produced by its oxidation at the three-phase boundary among the sol-gel, working electrode, and the gas phase. The sol-gel is processed to contain an electrolyte that also serves as a humidistat to maintain a constant water activity even in the presence the gas chromatographic mobile phase. Response was demonstrated toward a diverse set of analytes, namely hydrogen, 1,2-ethandithiol, phenol, p-cresol, and thioanisole. Using flow injection amperometry of hydrogen with He as the carrier gas, 90% of the steady-state current was achieved in < 1s at a flow rate of 20mLmin -1 . A separation of 1,2-ethandithiol, phenol, p-cresol, and thioanisole at a 2.2mLmin -1 flow rate was achieved with respective detection limits (k = 3 criterion) of 4, 1, 3, and 70 ppmv when the working electrode potential was 800mV. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. New simulated gas detector offers realistic training for mine rescue teams

    Energy Technology Data Exchange (ETDEWEB)

    Bealko, S.B.; Alexander, D.; Chasko, L.L. [National Inst. for Occupational Safety and Health, Pittsburgh, PA (United States). Office of Mine Safety and Health Research; Holtan, J. [LightsOn Safety Solutions, Spring, TX (United States)

    2010-07-01

    The National Institute for Occupational Safety and Health, together with LightsOn Safety Solutions, evaluated 2 versions of a multi-gas simulated gas monitor system (GMS) in separate field trials with mine rescue teams. This paper described the GMS wireless simulation tool along with its development and testing. It also described the GMS functions for the initial phase of testing as well as plans for the next phase of research which may introduce tracking and automation features. The GMS requires a personal computer and uses a wireless local area network. The GMS teaches mine rescue members about gas detection and helps them understand the importance of gas concentrations. In addition, it promotes decision-making actions by team members and offers a more realistic method of receiving gas concentration readings using a simulated hand-held gas detector. The purpose of the evaluation was to determine if the electronic placard in the GMS could be used by mine rescue teams instead of the currently used cardboard placards, and if the functionality of the device was suitable, reliable and practical. Results from the second field trial demonstrated improvements with the GMS over the original prototype technology, particularly with regards to wireless and connectivity issues. The GMS was successfully incorporated into the mine rescue exercises as planned, with very few problems encountered. 4 refs., 2 figs.

  1. New simulated gas detector offers realistic training for mine rescue teams

    International Nuclear Information System (INIS)

    Bealko, S.B.; Alexander, D.; Chasko, L.L.

    2010-01-01

    The National Institute for Occupational Safety and Health, together with LightsOn Safety Solutions, evaluated 2 versions of a multi-gas simulated gas monitor system (GMS) in separate field trials with mine rescue teams. This paper described the GMS wireless simulation tool along with its development and testing. It also described the GMS functions for the initial phase of testing as well as plans for the next phase of research which may introduce tracking and automation features. The GMS requires a personal computer and uses a wireless local area network. The GMS teaches mine rescue members about gas detection and helps them understand the importance of gas concentrations. In addition, it promotes decision-making actions by team members and offers a more realistic method of receiving gas concentration readings using a simulated hand-held gas detector. The purpose of the evaluation was to determine if the electronic placard in the GMS could be used by mine rescue teams instead of the currently used cardboard placards, and if the functionality of the device was suitable, reliable and practical. Results from the second field trial demonstrated improvements with the GMS over the original prototype technology, particularly with regards to wireless and connectivity issues. The GMS was successfully incorporated into the mine rescue exercises as planned, with very few problems encountered. 4 refs., 2 figs.

  2. Natural gas pipeline leak detector based on NIR diode laser absorption spectroscopy.

    Science.gov (United States)

    Gao, Xiaoming; Fan, Hong; Huang, Teng; Wang, Xia; Bao, Jian; Li, Xiaoyun; Huang, Wei; Zhang, Weijun

    2006-09-01

    The paper reports on the development of an integrated natural gas pipeline leak detector based on diode laser absorption spectroscopy. The detector transmits a 1.653 microm DFB diode laser with 10 mW and detects a fraction of the backscatter reflected from the topographic targets. To eliminate the effect of topographic scatter targets, a ratio detection technique was used. Wavelength modulation and harmonic detection were used to improve the detection sensitivity. The experimental detection limit is 50 ppmm, remote detection for a distance up to 20 m away topographic scatter target is demonstrated. Using a known simulative leak pipe, minimum detectable pipe leak flux is less than 10 ml/min.

  3. Performance test of a micro-pattern stereo detector with two gas electron multipliers

    International Nuclear Information System (INIS)

    Barvich, T.; Bluem, P.; Erdmann, M.; Fahrer, M.; Kaercher, K.; Kuehn, F.; Moermann, D.; Mueller, Th.; Neuberger, D.; Roederer, F.; Simonis, H.J.; Skiba, A.; Thuemmel, W.H.; Weiler, Th.; Weseler, S.

    2002-01-01

    We report on the performance of a large micro-pattern detector with two gas electron multiplier foils and a two-layer readout structure at ground potential. The two readout layers each have a 406 μm pitch and cross at an effective angle of 6.7 deg. . This structure allows for two orthogonal coordinates to be determined. Using a muon beam at CERN together with a silicon tracking system, the position resolutions of the two coordinates are measured to be 50 μm and 1 mm respectively (1 standard deviation). The muon detection efficiency for the two-dimensional space points reaches 96%. The detector was found to be well operational over a wide range in the settings of the different electrical fields

  4. High resolution Cerenkov light imaging of induced positron distribution in proton therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Fujii, Kento; Morishita, Yuki; Okumura, Satoshi; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi 461-8673 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Aichi 462-8508 (Japan)

    2014-11-01

    Purpose: In proton therapy, imaging of the positron distribution produced by fragmentation during or soon after proton irradiation is a useful method to monitor the proton range. Although positron emission tomography (PET) is typically used for this imaging, its spatial resolution is limited. Cerenkov light imaging is a new molecular imaging technology that detects the visible photons that are produced from high-speed electrons using a high sensitivity optical camera. Because its inherent spatial resolution is much higher than PET, the authors can measure more precise information of the proton-induced positron distribution with Cerenkov light imaging technology. For this purpose, they conducted Cerenkov light imaging of induced positron distribution in proton therapy. Methods: First, the authors evaluated the spatial resolution of our Cerenkov light imaging system with a {sup 22}Na point source for the actual imaging setup. Then the transparent acrylic phantoms (100 × 100 × 100 mm{sup 3}) were irradiated with two different proton energies using a spot scanning proton therapy system. Cerenkov light imaging of each phantom was conducted using a high sensitivity electron multiplied charge coupled device (EM-CCD) camera. Results: The Cerenkov light’s spatial resolution for the setup was 0.76 ± 0.6 mm FWHM. They obtained high resolution Cerenkov light images of the positron distributions in the phantoms for two different proton energies and made fused images of the reference images and the Cerenkov light images. The depths of the positron distribution in the phantoms from the Cerenkov light images were almost identical to the simulation results. The decay curves derived from the region-of-interests (ROIs) set on the Cerenkov light images revealed that Cerenkov light images can be used for estimating the half-life of the radionuclide components of positrons. Conclusions: High resolution Cerenkov light imaging of proton-induced positron distribution was possible. The

  5. High resolution Cerenkov light imaging of induced positron distribution in proton therapy

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Fujii, Kento; Morishita, Yuki; Okumura, Satoshi; Komori, Masataka; Toshito, Toshiyuki

    2014-01-01

    Purpose: In proton therapy, imaging of the positron distribution produced by fragmentation during or soon after proton irradiation is a useful method to monitor the proton range. Although positron emission tomography (PET) is typically used for this imaging, its spatial resolution is limited. Cerenkov light imaging is a new molecular imaging technology that detects the visible photons that are produced from high-speed electrons using a high sensitivity optical camera. Because its inherent spatial resolution is much higher than PET, the authors can measure more precise information of the proton-induced positron distribution with Cerenkov light imaging technology. For this purpose, they conducted Cerenkov light imaging of induced positron distribution in proton therapy. Methods: First, the authors evaluated the spatial resolution of our Cerenkov light imaging system with a 22 Na point source for the actual imaging setup. Then the transparent acrylic phantoms (100 × 100 × 100 mm 3 ) were irradiated with two different proton energies using a spot scanning proton therapy system. Cerenkov light imaging of each phantom was conducted using a high sensitivity electron multiplied charge coupled device (EM-CCD) camera. Results: The Cerenkov light’s spatial resolution for the setup was 0.76 ± 0.6 mm FWHM. They obtained high resolution Cerenkov light images of the positron distributions in the phantoms for two different proton energies and made fused images of the reference images and the Cerenkov light images. The depths of the positron distribution in the phantoms from the Cerenkov light images were almost identical to the simulation results. The decay curves derived from the region-of-interests (ROIs) set on the Cerenkov light images revealed that Cerenkov light images can be used for estimating the half-life of the radionuclide components of positrons. Conclusions: High resolution Cerenkov light imaging of proton-induced positron distribution was possible. The authors

  6. Pulse Shape Analysis and Discrimination for Silicon-Photomultipliers in Helium-4 Gas Scintillation Neutron Detector

    Science.gov (United States)

    Barker, Cathleen; Zhu, Ting; Rolison, Lucas; Kiff, Scott; Jordan, Kelly; Enqvist, Andreas

    2018-01-01

    Using natural helium (helium-4), the Arktis 180-bar pressurized gas scintillator is capable of detecting and distinguishing fast neutrons and gammas. The detector has a unique design of three optically separated segments in which 12 silicon-photomultiplier (SiPM) pairs are positioned equilaterally across the detector to allow for them to be fully immersed in the helium-4 gas volume; consequently, no additional optical interfaces are necessary. The SiPM signals were amplified, shaped, and readout by an analog board; a 250 MHz, 14-bit digitizer was used to examine the output pulses from each SiPMpair channel. The SiPM over-voltage had to be adjusted in order to reduce pulse clipping and negative overshoot, which was observed for events with high scintillation production. Pulse shaped discrimination (PSD) was conducted by evaluating three different parameters: time over threshold (TOT), pulse amplitude, and pulse integral. In order to differentiate high and low energy events, a 30ns gate window was implemented to group pulses from two SiPM channels or more for the calculation of TOT. It was demonstrated that pulses from a single SiPM channel within the 30ns window corresponded to low-energy gamma events while groups of pulses from two-channels or more were most likely neutron events. Due to gamma pulses having lower pulse amplitude, the percentage of measured gamma also depends on the threshold value in TOT calculations. Similarly, the threshold values were varied for the optimal PSD methods of using pulse amplitude and pulse area parameters. Helium-4 detectors equipped with SiPMs are excellent for in-the-field radiation measurement of nuclear spent fuel casks. With optimized PSD methods, the goal of developing a fuel cask content monitoring and inspection system based on these helium-4 detectors will be achieved.

  7. Visual detection of gas shows from coal core and cuttings using liquid leak detector

    Energy Technology Data Exchange (ETDEWEB)

    Barker, C.E. [United States Geological Survey, Denver, CO (United States)

    2006-09-15

    Coal core descriptions are difficult to obtain, as they must be obtained immediately after the core is retrieved and before the core is closed in a canister. This paper described a method of marking gas shows on a core surface by coating the core with a water-based liquid leak detector and photographing the subsequent foam developed on the core surface while the core is still in the core tray. Coals from a borehole at the Yukon Flats Basin in Alaska and the Maverick Basin in Texas were used to illustrate the method. Drilling mud and debris were removed from the coal samples before the leak detector solution was applied onto the core surfaces. A white froth or dripping foam developed rapidly at gas shows on the sample surfaces. A hand-held lens and a binocular microscope were used to magnify the foaming action. It was noted that foaming was not continuous across the core surface, but was restricted to localized points along the surface. It was suggested that the localized point foaming may have resulted from the coring process. However, the same tendency toward point gas show across the sample surface was found in some hard, well-indurated samples that still had undisturbed bedding and other sedimentary structures. It was concluded that gas shows marked as separate foam centres may indicate a real condition of local permeability paths. Results suggested that the new gas show detection method could be used in core selection studies to reduce the costs of exploration programs. 6 refs., 4 figs.

  8. The PASERO Project: parallel and serial readout systems for gas proportional synchrotron radiation X-ray detectors

    CERN Document Server

    Koch, M H J; Briquet-Laugier, F; Epstein, A; Sheldon, S; Beloeuvre, E; Gabriel, A; Hervé, C; Kocsis, M; Koschuch, A; Laggner, P; Leingartner, W; Raad-Iseli, C D; Reimann, T; Golding, F; Torki, K

    2001-01-01

    A project aiming at producing more efficient position sensitive gas proportional detectors and readout systems is presented. An area detector with reduced electrode spacing and a spatial resolution of 0.5 mm and two time to digital convertors (TDC) based on ASICs were produced. The first TDC, intended for use with linear detectors, relies on time to space conversion, whereas the second one, for area detectors, uses a ring oscillator with a phase locked loop. A parallel readout system for multi-anode detectors aiming at a maximum count rate extensively uses RISC microcontrollers. An electronic simulator of linear detectors built for test purposes and a mechanical chopper used for attenuation of the X-ray beam are also briefly described.

  9. First experimental results and simulation for gas optimisation of the MART-LIME detector

    International Nuclear Information System (INIS)

    Bazzano, A.; Brunetti, M.T.; Cocchi, M.; Hall, C.J.; Lewis, R.A.; Natalucci, L.; Ortuno-Prados, F.; Ubertini, P.

    1996-01-01

    A large area high pressure multi-wire proportional counter (MWPC), with both spatial and spectroscopic capabilities, is being jointly developed by the Istituto di Astrofisica Spaziale (IAS), CNR, Frascati, Italy and the Daresbury Laboratory (DL), Warrington, UK as part of the MART-LIME telescope. Recent test results (October-December 1995) carried out at the DL facilities are presented. A brief study, by means of a simulation program, on the possible gas mixtures to be employed in the MART-LIME detector is also reported. The results of the simulation are compared with the experimental data obtained from the tests. (orig.)

  10. BiCMOS amplifier-discriminator integrated circuit for gas-filled detector readout

    International Nuclear Information System (INIS)

    Herve, C.; Dzahini, D.; Le Caer, T.; Richer, J.-P.; Torki, K.

    2005-01-01

    The paper presents a 16-channel amplifier-discriminator designed in BiCMOS technology. It will be used for the binary parallel readout of gas-filled detectors being designed at the European Synchrotron Radiation Facility. The circuit (named AMS211) has been manufactured. The measured transimpedance gain (400 KΩ), bandwidth (25 MHz) and noise (1570 e - +95 e - /pF ENC) well match the simulated results. The discriminator thresholds are individually controlled by built-in Digital to Analogue Converter. The experience gained with a first prototype of readout electronics indicates that the AMS211 should meet our requirements

  11. BiCMOS amplifier-discriminator integrated circuit for gas-filled detector readout

    Energy Technology Data Exchange (ETDEWEB)

    Herve, C. [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France)]. E-mail: herve@esrf.fr; Dzahini, D. [Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Le Caer, T. [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France); Richer, J.-P. [Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Torki, K. [Laboratoire TIMA, Grenoble (France)

    2005-03-21

    The paper presents a 16-channel amplifier-discriminator designed in BiCMOS technology. It will be used for the binary parallel readout of gas-filled detectors being designed at the European Synchrotron Radiation Facility. The circuit (named AMS211) has been manufactured. The measured transimpedance gain (400 K{omega}), bandwidth (25 MHz) and noise (1570 e{sup -}+95 e{sup -}/pF ENC) well match the simulated results. The discriminator thresholds are individually controlled by built-in Digital to Analogue Converter. The experience gained with a first prototype of readout electronics indicates that the AMS211 should meet our requirements.

  12. Multiline digital radiographic imager study with synchronization to detector gas ion drift

    International Nuclear Information System (INIS)

    Peyret, O.

    1985-01-01

    This direct digital radiographic imager is based on X-ray detection in high pressure rare gas ionization chamber. This linear multidetector, from which scanning radiography is realized, records many lines together. Spatial resolution performance in scanning direction are made sure by scanning synchronization with ion drift in detector. After a physical study and a potential evaluation of its performances on mock-up, a 128 cell prototype has been realized. The first images give validation and limits of such a radiographic process [fr

  13. The IMB proton decay detector

    International Nuclear Information System (INIS)

    Svoboda, R.C.; Gajewski, W.; Kropp, W.R.; Reines, F.; Schultz, J.; Smith, D.W.; Sobel, H.; Wuest, C.; Bionta, R.M.; Cortez, B.G.; Errede, S.; Foster, G.W.; Greenberg, J.; Park, H.S.; Shumard, E.; Sinclair, D.; Stone, J.L.; Sulak, L.R.; Velde, J.C. van der; Goldhaber, M.; Blewitt, G.; Lehmann, E.; LoSecco, J.M.; Bratton, C.B.; Learned, J.; Svoboda, R.; Jones, T.W.; Ramana Murthy, P.V.

    1983-01-01

    A description is given of the Irvine-Michigan-Brookhaven proton decay detector which is nearing completion in a salt mine in Cleveland, Ohio, U.S.A. The detector is a water Cerenkov one with a fiducial volume of 4,000 tons and a threshold of 24 MeV. Initial results indicate that the detector is working according to specification and has a high potential for deep underground cosmic ray applications. I will give a brief account of the IMB detector construction and operation and also its present status and possible cosmic ray applications. (orig.)

  14. Assessment of pesticide residues in some fruits using gas chromatography coupled with micro electron capture detector

    International Nuclear Information System (INIS)

    Latif, Y.; Sherazi, S.T.H.; Bhanger, M.I.

    2011-01-01

    A very sensitive analytical method for the determination of 26 pesticides in some fruits based on solid phase extraction (SPE) cleanup was developed using gas chromatography (GC) coupled with micro electron capture detector (mu ECD). The identity of the pesticides was confirmed by gas chromatography mass spectroscopy (GC-MS) using selected ion monitoring (SIM) mode. Ethyl acetate was used as a solvent for the extraction of pesticide residues with assistance of sonication. For cleanup an octadecyl, C18 SPE column was used. A linear response of mu ECD was observed for all pesticides with good correlation coefficients (>0.9992). Proposed method was successfully applied for the determination of pesticide residues in the orange, apple, and grape fruits. Average recoveries achieved for all of the pesticides at fortification levels of 0.05, 1.0 and 2.0 mu g g/sup -1/ in analyzed fruits were above 90% with relative standard deviations (RSD) less than 6%. (author)

  15. Fission signal detection using helium-4 gas fast neutron scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, J. M., E-mail: lewisj@ufl.edu; Kelley, R. P.; Jordan, K. A. [Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611 (United States); Murer, D. [Arktis Radiation Detectors Ltd., 8045 Zurich (Switzerland)

    2014-07-07

    We demonstrate the unambiguous detection of the fission neutron signal produced in natural uranium during active neutron interrogation using a deuterium-deuterium fusion neutron generator and a high pressure {sup 4}He gas fast neutron scintillation detector. The energy deposition by individual neutrons is quantified, and energy discrimination is used to differentiate the induced fission neutrons from the mono-energetic interrogation neutrons. The detector can discriminate between different incident neutron energies using pulse height discrimination of the slow scintillation component of the elastic scattering interaction between a neutron and the {sup 4}He atom. Energy histograms resulting from this data show the buildup of a detected fission neutron signal at higher energies. The detector is shown here to detect a unique fission neutron signal from a natural uranium sample during active interrogation with a (d, d) neutron generator. This signal path has a direct application to the detection of shielded nuclear material in cargo and air containers. It allows for continuous interrogation and detection while greatly minimizing the potential for false alarms.

  16. Acoustic dew point and bubble point detector for gas condensates and reservoir fluids

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, A.; Hu, Y.; Thomas, F. B.; Bennion, D. B.; Jamaluddin, A. K. M. [Hycal Energy Research Labs. Ltd., Calgary, AB (Canada)

    1997-08-01

    Detailed knowledge of bubblepoint and dewpoint pressures at reservoir temperature are crucial for natural gas processing, transportation, metering and utilization. This paper introduces a new acoustic dewpoint and bubblepoint detector that can be applied to a broad range of phase transitions, including very lean gas systems and opaque heavy oils. The system uses two acoustic transducers, one to stimulate and the other to detect normal mode vibrations of reservoir fluids in a small cylindrical resonator. The acoustic spectra are recorded at close intervals throughout the phase envelope, along with temperature, pressure and volume measurements, and the data is processed to obtain the specific condition of phase transition. Results of two systems, a binary mixture and live reservoir fluid, are presented. The detector system is claimed to be capable of operation in an isothermal mode with variable volume, and in a constant volume mode with variable temperatures. Interpretation of results is free of operator subjectivity; they show excellent agreement with results obtained by visual methods and equations of state calculations. 4 refs., 2 tabs., 4 figs.

  17. Single channel analog pulse processor Asic for gas proportional counters and SI detector

    International Nuclear Information System (INIS)

    Chandratre, V.B.; Sarkar, Soumen; Kataria, S.K.; Viyogi, Y.P.

    2005-01-01

    The paper presents the design and development of a single channel pulse processor in short Singleplex ASIC targeted for gas proportional counters/Si detectors. The design is optimized for the dynamic range of +500 fC to -500 fC with provision for externally adjusted pole-zero cancellation. A dedicated filter based on the de-convolution principle is used for the cancellation of the long hyperbolic signal tail produced by the slow drift of ions, typical in gas proportional with the filter time constants derived from the actual detector input signal shape. The pole-zero adjustment can be done by external dc voltage to achieve perfect base-line recovery to 1% after 5 μs. The simulated 0 pf noise is 500 e - rms for the peaking time of 1.2 μs with noise slope of 7e - -. The gain is 3.4 mv/fC over the entire linear dynamic range with power dissipation of 13 mW. This design is a modified version of Indiplex chip with features dynamic range equal gain on both polarities with nearly same noise and serves as diagnostic chip for Indiplex. The chip can be used for radiation monitoring instruments. (author)

  18. {sup 10}B multi-grid proportional gas counters for large area thermal neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, K. [ESS, P.O. Box 176, SE-221 00 Lund (Sweden); Bigault, T. [ILL, BP 156, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Birch, J. [Linköping University, SE-581, 83 Linköping (Sweden); Buffet, J. C.; Correa, J. [ILL, BP 156, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Hall-Wilton, R. [ESS, P.O. Box 176, SE-221 00 Lund (Sweden); Hultman, L. [Linköping University, SE-581, 83 Linköping (Sweden); Höglund, C. [ESS, P.O. Box 176, SE-221 00 Lund (Sweden); Linköping University, SE-581, 83 Linköping (Sweden); Guérard, B., E-mail: guerard@ill.fr [ILL, BP 156, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Jensen, J. [Linköping University, SE-581, 83 Linköping (Sweden); Khaplanov, A. [ILL, BP 156, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); ESS, P.O. Box 176, SE-221 00 Lund (Sweden); Kirstein, O. [Linköping University, SE-581, 83 Linköping (Sweden); Piscitelli, F.; Van Esch, P. [ILL, BP 156, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Vettier, C. [ESS, P.O. Box 176, SE-221 00 Lund (Sweden)

    2013-08-21

    {sup 3}He was a popular material in neutrons detectors until its availability dropped drastically in 2008. The development of techniques based on alternative convertors is now of high priority for neutron research institutes. Thin films of {sup 10}B or {sup 10}B{sub 4}C have been used in gas proportional counters to detect neutrons, but until now, only for small or medium sensitive area. We present here the multi-grid design, introduced at the ILL and developed in collaboration with ESS for LAN (large area neutron) detectors. Typically thirty {sup 10}B{sub 4}C films of 1 μm thickness are used to convert neutrons into ionizing particles which are subsequently detected in a proportional gas counter. The principle and the fabrication of the multi-grid are described and some preliminary results obtained with a prototype of 200 cm×8 cm are reported; a detection efficiency of 48% has been measured at 2.5 Å with a monochromatic neutron beam line, showing the good potential of this new technique.

  19. Development of a cost efficient methodology to perform allocation of flammable and toxic gas detectors applying CFD tools

    Energy Technology Data Exchange (ETDEWEB)

    Storch, Rafael Brod; Rocha, Gean Felipe Almeida [Det Norske Veritas (DNV), Rio de Janeiro, RJ (Brazil); Nalvarte, Gladys Augusta Zevallos [Det Norske Veritas (DNV), Novik (Norway)

    2012-07-01

    This paper is aimed to present a computational procedure for flammable and toxic gas detector allocation and quantification developed by DNV. The proposed methodology applies Computational Fluid Dynamics (CFD) simulations as well as operational and safety characteristics of the analyzed region to assess the optimal number of toxic and flammable gas detectors and their optimal location. A probabilistic approach is also used when applying the DNV software ThorEXPRESSLite, following NORSOK Z013 Annex G and presented in HUSER et al. 2000 and HUSER et al. 2001, when the flammable gas detectors are assessed. A DNV developed program, DetLoc, is used to run in an iterative way the procedure described above leading to an automatic calculation of the gas detectors location and number. The main advantage of the methodology presented above is the independence of human interaction in the gas detector allocation leading to a more precise and free of human judgment allocation. Thus, a reproducible allocation is generated when comparing several different analyses and a global criteria appliance is guaranteed through different regions in the same project. A case study is presented applying the proposed methodology. (author)

  20. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    International Nuclear Information System (INIS)

    Poole, B.R.; Harris, J.R.

    2011-01-01

    The Naval Postgraduate School (NPS), Niowave, Inc., and Boeing have recently demonstrated operation of the first superconducting RF electron gun based on a quarter wave resonator structure. In preliminary tests, this gun has produced 10 ps long bunches with charge in excess of 78 pC, and with beam energy up to 396 keV. Initial testing occurred at Niowave's Lansing, MI facility, but the gun and diagnostic beam line are planned for installation in California in the near future. The design of the diagnostic beam line is conducive to the addition of a Cerenkov radiator without interfering with other beam line operations. Design and simulations of a Cerenkov radiator, consisting of a dielectric lined waveguide will be presented. The dispersion relation for the structure is determined and the beam interaction is studied using numerical simulations. The characteristics of the microwave radiation produced in both the short and long bunch regimes will be presented.

  1. Utilizing the power of Cerenkov light with nanotechnology

    Science.gov (United States)

    Shaffer, Travis M.; Pratt, Edwin C.; Grimm, Jan

    2017-02-01

    The characteristic blue glow of Cerenkov luminescence (CL) arises from the interaction between a charged particle travelling faster than the phase velocity of light and a dielectric medium, such as water or tissue. As CL emanates from a variety of sources, such as cosmic events, particle accelerators, nuclear reactors and clinical radionuclides, it has been used in applications such as particle detection, dosimetry, and medical imaging and therapy. The combination of CL and nanoparticles for biomedicine has improved diagnosis and therapy, especially in oncological research. Although radioactive decay itself cannot be easily modulated, the associated CL can be through the use of nanoparticles, thus offering new applications in biomedical research. Advances in nanoparticles, metamaterials and photonic crystals have also yielded new behaviours of CL. Here, we review the physics behind Cerenkov luminescence and associated applications in biomedicine. We also show that by combining advances in nanotechnology and materials science with CL, new avenues for basic and applied sciences have opened.

  2. Cerenkov Luminescence Tomography for In Vivo Radiopharmaceutical Imaging

    Directory of Open Access Journals (Sweden)

    Jianghong Zhong

    2011-01-01

    Full Text Available Cerenkov luminescence imaging (CLI is a cost-effective molecular imaging tool for biomedical applications of radiotracers. The introduction of Cerenkov luminescence tomography (CLT relative to planar CLI can be compared to the development of X-ray CT based on radiography. With CLT, quantitative and localized analysis of a radiopharmaceutical distribution becomes feasible. In this contribution, a feasibility study of in vivo radiopharmaceutical imaging in heterogeneous medium is presented. Coupled with a multimodal in vivo imaging system, this CLT reconstruction method allows precise anatomical registration of the positron probe in heterogeneous tissues and facilitates the more widespread application of radiotracers. Source distribution inside the small animal is obtained from CLT reconstruction. The experimental results demonstrated that CLT can be employed as an available in vivo tomographic imaging of charged particle emitters in a heterogeneous medium.

  3. Measurement of 40K by Cerenkov Effect in foods

    International Nuclear Information System (INIS)

    Davila R, J. I.; Cancino T, F.; Lopez del R, H.; Mireles G, F.

    2013-10-01

    The 40 K is a natural radioactive isotope of the potassium element that decays mainly by beta and gamma radiation emission. Although the gamma spectrometry is generally used for its measuring, the energy of the beta radiation is enough to produce Cerenkov radiation in water. Taking advantage of the high efficiency of the liquid scintillation counting, a procedure to measure 40 K was developed through the Cerenkov radiation using a liquid scintillation counter. The methodology was applied in foods with high content of potassium like tomato, banana, and in olive. The efficiency and sensibility of the counting were superior to those reported for gamma spectrometry and the chemical recovery of potassium was of 82.3%. The activity of 40 K varied between 2.9 and 8.4 Bq/kg in banana, between 12.3 and 19 Bq/kg in tomato, and in olive was minor to the detectable minimum activity of the method. (Author)

  4. Accuracy of Cerenkov measurements using a liquid scintillation spectrometer

    International Nuclear Information System (INIS)

    Takiue, Makoto; Natake, Takashi

    1996-01-01

    Cerenkov counting efficiency varies with colour quenching and sample turbidity. The activity in a plastic vial can be determined accurately with a colour quenching correction technique, regardless of the presence or absence or turbidity in a sample. On the other hand, the error of the measured activity in a glass vial becomes large with increasing sample turbidity due to the dissimilarity of the quench correction curves for non-turbid and turbid samples. (Author)

  5. Cerenkov maser operation at lower-mm wavelengths

    International Nuclear Information System (INIS)

    Garate, E.; Cook, R.; Heim, P.; Layman, R.; Walsh, J.

    1985-01-01

    The basic operating principles of Cerenkov maser oscillators are briefly reviewed and the experimental performance of a 3-mm device is discussed. A power level of approximately 100 kW was achieved at 88 GHz and voltage tuning from 84 to 128 GHz on the fundamental TM 01 mode was observed. Operation on higher-order modes at frequencies up to 300--320 GHz was demonstrated, and a two-stage buncher-amplifier configuration was investigated

  6. Cerenkov luminescence tomography based on preconditioning orthogonal matching pursuit

    Science.gov (United States)

    Liu, Haixiao; Hu, Zhenhua; Wang, Kun; Tian, Jie; Yang, Xin

    2015-03-01

    Cerenkov luminescence imaging (CLI) is a novel optical imaging method and has been proved to be a potential substitute of the traditional radionuclide imaging such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). This imaging method inherits the high sensitivity of nuclear medicine and low cost of optical molecular imaging. To obtain the depth information of the radioactive isotope, Cerenkov luminescence tomography (CLT) is established and the 3D distribution of the isotope is reconstructed. However, because of the strong absorption and scatter, the reconstruction of the CLT sources is always converted to an ill-posed linear system which is hard to be solved. In this work, the sparse nature of the light source was taken into account and the preconditioning orthogonal matching pursuit (POMP) method was established to effectively reduce the ill-posedness and obtain better reconstruction accuracy. To prove the accuracy and speed of this algorithm, a heterogeneous numerical phantom experiment and an in vivo mouse experiment were conducted. Both the simulation result and the mouse experiment showed that our reconstruction method can provide more accurate reconstruction result compared with the traditional Tikhonov regularization method and the ordinary orthogonal matching pursuit (OMP) method. Our reconstruction method will provide technical support for the biological application for Cerenkov luminescence.

  7. Gamma ray and neutrino detector facility (GRANDE), Task C

    International Nuclear Information System (INIS)

    Sobel, H.W.; Yodh, G.B.

    1991-08-01

    GRANDE is an imaging, water Cerenkov detector, which combines in one facility an extensive air shower array and a high-energy neutrino detector. We proposed that the detector be constructed in phases, beginning with an active detector area of 31,000 m 2 (GRANDE-I) 2 and expanding to a final size of 100,000--150,00 m 2 . Some of the characteristics of GRANDE-I are discussed in this paper

  8. GOSSIP: A vertex detector combining a thin gas layer as signal generator with a CMOS readout pixel array

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, M. [CERN/MediPix Consortium, Geneva (Switzerland); Heijne, E.H.M. [CERN/MediPix Consortium, Geneva (Switzerland); Llopart, X. [CERN/MediPix Consortium, Geneva (Switzerland); Colas, P. [DAPNIA, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Giganon, A. [DAPNIA, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Giomataris, Y. [DAPNIA, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Chefdeville, M. [NIKHEF, Amsterdam (Netherlands); Colijn, A.P. [NIKHEF, Amsterdam (Netherlands); Fornaini, A. [NIKHEF, Amsterdam (Netherlands); Graaf, H. van der [NIKHEF, Amsterdam (Netherlands)]. E-mail: vdgraaf@nikhef.nl; Kluit, P. [NIKHEF, Amsterdam (Netherlands); Timmermans, J. [NIKHEF, Amsterdam (Netherlands); Visschers, J.L. [NIKHEF, Amsterdam (Netherlands); Schmitz, J. [University of Twente/MESA (Netherlands)

    2006-05-01

    A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50{mu}m above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as {delta}-rays. With a gas layer thickness of only 1mm, the device could be applied as vertex detector, outperforming all Si-based detectors.

  9. GOSSIP: A vertex detector combining a thin gas layer as signal generator with a CMOS readout pixel array

    International Nuclear Information System (INIS)

    Campbell, M.; Heijne, E.H.M.; Llopart, X.; Colas, P.; Giganon, A.; Giomataris, Y.; Chefdeville, M.; Colijn, A.P.; Fornaini, A.; Graaf, H. van der; Kluit, P.; Timmermans, J.; Visschers, J.L.; Schmitz, J.

    2006-01-01

    A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50μm above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as δ-rays. With a gas layer thickness of only 1mm, the device could be applied as vertex detector, outperforming all Si-based detectors

  10. GOSSIP: A vertex detector combining a thin gas layer as signal generator with a CMOS readout pixel array

    Science.gov (United States)

    Campbell, M.; Heijne, E. H. M.; Llopart, X.; Colas, P.; Giganon, A.; Giomataris, Y.; Chefdeville, M.; Colijn, A. P.; Fornaini, A.; van der Graaf, H.; Kluit, P.; Timmermans, J.; Visschers, J. L.; Schmitz, J.

    2006-05-01

    A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50 μm above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as δ-rays. With a gas layer thickness of only 1 mm, the device could be applied as vertex detector, outperforming all Si-based detectors.

  11. Measurement of {sup 40}K by Cerenkov Effect in foods; Medicion de {sup 40}K por Efecto Cerenkov en alimentos

    Energy Technology Data Exchange (ETDEWEB)

    Davila R, J. I.; Cancino T, F.; Lopez del R, H.; Mireles G, F., E-mail: idavilara@gmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico)

    2013-10-15

    The {sup 40}K is a natural radioactive isotope of the potassium element that decays mainly by beta and gamma radiation emission. Although the gamma spectrometry is generally used for its measuring, the energy of the beta radiation is enough to produce Cerenkov radiation in water. Taking advantage of the high efficiency of the liquid scintillation counting, a procedure to measure {sup 40}K was developed through the Cerenkov radiation using a liquid scintillation counter. The methodology was applied in foods with high content of potassium like tomato, banana, and in olive. The efficiency and sensibility of the counting were superior to those reported for gamma spectrometry and the chemical recovery of potassium was of 82.3%. The activity of {sup 40}K varied between 2.9 and 8.4 Bq/kg in banana, between 12.3 and 19 Bq/kg in tomato, and in olive was minor to the detectable minimum activity of the method. (Author)

  12. A gas microstrip detector for X-ray imaging with readout of the anode by resistive division

    CERN Document Server

    Bateman, J E; Lodge, A B; Stephenson, R; Mutikainen, R; Suni, I; Morse, J

    2002-01-01

    The results are presented of a development programme aimed at the validation of the key concepts and technologies for the construction of a two-dimensional X-ray detector based on gas microstrip detector technology using resistive division along the anode to achieve the second dimension. A prototype detector and its associated electronic readout system have been developed which demonstrate the capability of a spatial resolution (standard deviation) of approximately ((1)/(1000)) of the working aperture combined with readout rates of up to 400 kHz per anode. Test results and a description of the position sensing circuitry are given.

  13. Performance Testing of Tracer Gas and Tracer Aerosol Detectors for use in Radionuclide NESHAP Compliance Testing

    Energy Technology Data Exchange (ETDEWEB)

    Fuehne, David Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lattin, Rebecca Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-28

    The Rad-NESHAP program, part of the Air Quality Compliance team of LANL’s Compliance Programs group (EPC-CP), and the Radiation Instrumentation & Calibration team, part of the Radiation Protection Services group (RP-SVS), frequently partner on issues relating to characterizing air flow streams. This memo documents the most recent example of this partnership, involving performance testing of sulfur hexafluoride detectors for use in stack gas mixing tests. Additionally, members of the Rad-NESHAP program performed a functional trending test on a pair of optical particle counters, comparing results from a non-calibrated instrument to a calibrated instrument. Prior to commissioning a new stack sampling system, the ANSI Standard for stack sampling requires that the stack sample location must meet several criteria, including uniformity of tracer gas and aerosol mixing in the air stream. For these mix tests, tracer media (sulfur hexafluoride gas or liquid oil aerosol particles) are injected into the stack air stream and the resulting air concentrations are measured across the plane of the stack at the proposed sampling location. The coefficient of variation of these media concentrations must be under 20% when evaluated over the central 2/3 area of the stack or duct. The instruments which measure these air concentrations must be tested prior to the stack tests in order to ensure their linear response to varying air concentrations of either tracer gas or tracer aerosol. The instruments used in tracer gas and aerosol mix testing cannot be calibrated by the LANL Standards and Calibration Laboratory, so they would normally be sent off-site for factory calibration by the vendor. Operational requirements can prevent formal factory calibration of some instruments after they have been used in hazardous settings, e.g., within a radiological facility with potential airborne contamination. The performance tests described in this document are intended to demonstrate the reliable

  14. An optical fiber-based flexible readout system for micro-pattern gas detectors

    Science.gov (United States)

    Li, C.; Feng, C. Q.; Zhu, D. Y.; Liu, S. B.; An, Q.

    2018-04-01

    This paper presents an optical fiber-based readout system that is intended to provide a general purpose multi-channel readout solution for various Micro-Pattern Gas Detectors (MPGDs). The proposed readout system is composed of several front-end cards (FECs) and a data collection module (DCM). The FEC exploits the capability of an existing 64-channel generic TPC readout ASIC chip, named AGET, to implement 256 channels readout. AGET offers FEC a large flexibility in gain range (4 options from 120 fC to 10 pC), peaking time (16 options from 50 ns to 1 us) and sampling freqency (100 MHz max.). The DCM contains multiple 1 Gbps optical fiber serial link interfaces that allow the system scaling up to 1536 channels with 6 FECs and 1 DCM. Further scaling up is possible through cascading of multiple DCMs, by configuring one DCM as a master while other DCMs in slave mode. This design offers a rapid readout solution for different application senario. Tests indicate that the nonlinearity of each channel is less than 1%, and the equivalent input noise charge is typically around 0.7 fC in RMS (root mean square), with a noise slope of about 0.01 fC/pF. The system level trigger rate limit is about 700 Hz in all channel readout mode. When in hit channel readout mode, supposing that typically 10 percent of channels are fired, trigger rate can go up to about 7 kHz. This system has been tested with Micromegas detector and GEM detector, confirming its capability in MPGD readout. Details of hardware and FPGA firmware design, as well as system performances, are described in the paper.

  15. Experimental investigation of mass efficiency curve for alpha radioactivity counting using a gas-proportional detector

    International Nuclear Information System (INIS)

    Semkow, T.M.; Bari, A.; Parekh, P.P.; Haines, D.K.; Gao, H.; Bolden, A.N.; Dahms, K.S.; Scarpitta, S.C.; Thern, R.E.; Velazquez, S.

    2004-01-01

    Gross α counting of evaporated water residues offers a simple method for screening α radioactivity in water for both public health and emergency purposes. The evaporation process for water has been improved by using a combination of roughening of the surface of counting planchettes, two-stage evaporation, and temperature-controlled block heating. The efficiency of the gas-proportional detector for α-particle detection in water residues was studied as a function of sample mass-thickness in the range between 0.1 and 13 mg cm -2 . The effect of α energy on the efficiency, as well as moisture absorption on the samples, were studied using 230 Th, 238 U, 239 Pu, 241 Am, and 244 Cm radionuclides. Also, α-to-β crosstalk was investigated as a function of sample mass for 230 Th, 239 Pu, 210 Po, 241 Am, and 244 Cm. The improved method can also be applied for gross α detection in biological fluids

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

    Energy Technology Data Exchange (ETDEWEB)

    Rubery, M. S.; Horsfield, C. J. [Plasma Physics Department, AWE plc, Reading RG7 4PR (United Kingdom); Herrmann, H.; Kim, Y.; Mack, J. M.; Young, C.; Evans, S.; Sedillo, T.; McEvoy, A.; Caldwell, S. E. [Plasma Physics Department, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Grafil, E.; Stoeffl, W. [Physics, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Milnes, J. S. [Photek Limited UK, 26 Castleham Road, St. Leonards-on-sea TN38 9NS (United Kingdom)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, H. W., E-mail: herrmann@lanl.gov; Kim, Y. H.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Malone, R. M. [National Security Technologies, LLC, Los Alamos, New Mexico 87544 (United States); Rubery, M. S.; Horsfield, C. J. [Atomic Weapons Establishment, Aldermaston, Berkshire RG7 4PR (United Kingdom); Stoeffl, W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Zylstra, A. B. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Shmayda, W. T. [Laboratory for Laser Energetics, Rochester, New York 14623 (United States)

    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.

  18. Candidates to replace R-12 as a radiator gas in Cherenkov detectors

    Science.gov (United States)

    Harvey, Allan H.; Paulechka, Eugene; Egan, Patrick F.

    2018-06-01

    Dichlorodifluoromethane (R-12) has been widely used as a radiator gas in pressure threshold Cherenkov detectors for high-energy particle physics. However, that compound is becoming unavailable due to the Montreal Protocol. To find a replacement with suitably high refractive index, we use a combination of theory and experiment to examine the polarizability and refractivity of several non-ozone-depleting compounds. Our measurements show that the fourth-generation refrigerants R-1234yf (2,3,3,3-tetrafluoropropene) and R-1234ze(E) (trans-1,3,3,3-tetrafluoropropene) have sufficient refractivity to replace R-12 in this application. If the slight flammability of these compounds is a problem, two nonflammable alternatives are R-218 (octafluoropropane), which has a high Global Warming Potential, and R-13I1 (trifluoroiodomethane), which has low Ozone Depletion Potential and Global Warming Potential but may not be sufficiently inert.

  19. DUMAND: the ocean as a neutrino detector

    International Nuclear Information System (INIS)

    Roberts, A.; Blood, H.; Learned, J.; Reines, F.

    1976-01-01

    It is looked for the possibility of using the ocean as a neutrino detector. Neutrino produced interactions result in charged particles which generate Cerenkov 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 are the detection of neutrinos emitted in gravitational collapse of stars for example. (BJ) [de

  20. Low-noise mid-IR upconversion detector for improved IR-degenerate four-wave mixing gas sensing

    DEFF Research Database (Denmark)

    Høgstedt, Lasse; Dam, Jeppe Seidelin; Sahlberg, Anna-Lena

    2014-01-01

    -to-noise ratio. The two detectors are compared for the detection of a coherent degenerate four-wave mixing (DFWM) signal in the mid-infrared, and applied to measure trace-level acetylene in a gas flow at atmospheric pressure, probing its fundamental rovibrational transitions. In addition to lower noise...

  1. Assessment of Pesticide Residues in Some Fruits Using Gas Chromatography Coupled with Micro Electron Capture Detector

    Directory of Open Access Journals (Sweden)

    M. I. Bhanger

    2011-12-01

    Full Text Available A very sensitive analytical method for the determination of 26 pesticides in some fruits based on solid phase extraction (SPE cleanup was developed using gas chromatography (GC coupled with micro electron capture detector (μECD. The identity of the pesticides was confirmed by gas chromatography mass spectroscopy (GC-MS using selected ion monitoring (SIM mode. Ethyl acetate was used as a solvent for the extraction of pesticide residues with assistance of sonication. For cleanup an octadecyl, C18 SPE column was used. A linear response of μECD was observed for all pesticides with good correlation coefficients (>0.9992. Proposed method was successfully applied for the determination of pesticide residues in the orange, apple, and grape fruits. Average recoveries achieved for all of the pesticides at fortification levels of 0.05, 1.0 and 2.0 μg g-1 in analyzed fruits were above 90% with relative standard deviations (RSD less than 6

  2. Simultaneous acquisition of X-ray spectra using a multi-wire, position-sensitive gas flow detector

    International Nuclear Information System (INIS)

    Beaven, Peter A.; Marmotti, Mauro; Kampmann, Reinhard; Knoth, Joachim; Schwenke, Heinrich

    2003-01-01

    A multi-wire, gas-filled position-sensitive detector has been developed for the simultaneous recording of wavelength-dispersed X-ray signals that enables X-ray fluorescence spectrometry with a limited multi-element capability in the low Z element range. Details of the modular construction of the detector are given. The detector performance was characterized using Al-Kα radiation and a variable slit system. The detector has been applied in a laboratory spectrometer equipped with an electron source and a double multilayer mirror device as the wavelength-dispersing element. Spectra from Al and Si obtained in the simultaneous acquisition mode show good agreement with calculations performed using a ray-tracing model

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

    Science.gov (United States)

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

    2017-01-01

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

  4. A low noise ASIC for two dimensional neutron gas detector with performance of high spatial resolution (Contract research)

    International Nuclear Information System (INIS)

    Yamagishi, Hideshi; Toh, Kentaro; Nakamura, Tatsuya; Sakasai, Kaoru; Soyama, Kazuhiko

    2012-02-01

    An ASD-ASIC (Amplifier-Shaper-Discriminator ASIC) with fast response and low noise performances has been designed for two-dimensional position sensitive neutron gas detectors (InSPaD). The InSPaD is a 2D neutron detector system with 3 He gas and provides a high spatial resolution by making distinction between proton and triton particles generated in the gas chamber. The new ASD-ASIC is required to have very low noise, a wide dynamic range, good output linearity and high counting rate. The new ASD-ASIC has been designed by using CMOS and consisted of 64-channel ASDs, a 16-channel multiplexer with LVTTL drivers and sum amplifier system for summing all analog signals. The performances were evaluated by the Spice simulation. It was confirmed that the new ASD-ASIC had very low noise performance, wide dynamic range and fast signal processing functions. (author)

  5. Small animal positron emission tomography with gas detectors. Simulations, prototyping, and quantitative image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Vernekohl, Don

    2014-04-15

    The physical background of limiting factors on spatial resolution and coincidence sensitivity were introduced, and details about the first sub-millimeter resolution preclinical PET scanner, the HIDAC, were described in this thesis. As the coincidence sensitivity of the HIDAC is rather moderate, the first subject of investigation was to study the sensitivity optimization potential of the HIDAC converter concept. The HIDAC photon converters consist of a stack of alternating conversion and insulation foils perforated with a dense matrix of holes. First, photon conversion and detection probabilities for different converter geometries were systematically explored with a Geant4 model of the HIDAC, which uses Monte-Carlo methods. Additionally, new charge transport in gas and detection models were developed, and their results for different hole dimensions were combined with the conversion probability outcomes. In a next step, it was explored whether the optimized converter hole patterns prospected by the simulations can be manufactured. In conclusion, currently only etching, screen printing, and drilling are potential methods for producing large-scale converters. Second, a test-bench was established to examine differently produced converter prototypes and to test the performance of newly developed readout electronics for the desired application. It was possible to verify that the developer version of the SPADIC works well if coupled to a MWPC/HIDAC-converter detector setup. In this combination, the setup was able to detect the majority of ionization clusters. This was validated by exploring the impact of drift thickness on the count rate. Furthermore, it was demonstrated that the test-bench is able to distinguish relative efficiency differences of converter prototypes with a precision of around 10%, if it was equipped with an extra drift layer. Additionally, single-lead-layer-converters were investigated, whereby the relative count rate difference between structured and

  6. THE IMAGING PROPERTIES OF THE GAS PIXEL DETECTOR AS A FOCAL PLANE POLARIMETER

    Energy Technology Data Exchange (ETDEWEB)

    Fabiani, S.; Costa, E.; Del Monte, E.; Muleri, F.; Soffitta, P.; Rubini, A. [INAF-IAPS, via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Bellazzini, R.; Brez, A.; De Ruvo, L.; Minuti, M.; Pinchera, M.; Sgró, C.; Spandre, G. [INFN Sezione di Pisa, Largo B. Pontecorvo, 3, I-56127 Pisa (Italy); Spiga, D.; Tagliaferri, G.; Pareschi, G.; Basso, S.; Citterio, O. [INAF-Osservatorio Astronomico di Brera, via Brera 28, I-20121 Milano (Italy); Burwitz, V.; Burkert, W., E-mail: sergio.fabiani@iaps.inaf.it [Max-Planck-Institut für extraterrestrische Physik, Gautinger Str. 45, D-82061 Neuired (Germany); and others

    2014-06-01

    X-rays are particularly suited to probing the physics of extreme objects. However, despite the enormous improvements of X-ray astronomy in imaging, spectroscopy, and timing, polarimetry remains largely unexplored. We propose the photoelectric polarimeter Gas Pixel Detector (GPD) as a candidate instrument to fill the gap created by more than 30 yr without measurements. The GPD, in the focus of a telescope, will increase the sensitivity of orders of magnitude. Moreover, since it can measure the energy, the position, the arrival time, and the polarization angle of every single photon, it allows us to perform polarimetry of subsets of data singled out from the spectrum, the light curve, or an image of the source. The GPD has an intrinsic, very fine imaging capability, and in this work we report on the calibration campaign carried out in 2012 at the PANTER X-ray testing facility of the Max-Planck-Institut für extraterrestrische Physik of Garching (Germany) in which, for the first time, we coupled it with a JET-X optics module with a focal length of 3.5 m and an angular resolution of 18 arcsec at 4.5 keV. This configuration was proposed in 2012 aboard the X-ray Imaging Polarimetry Explorer (XIPE) in response to the ESA call for a small mission. We derived the imaging and polarimetric performance for extended sources like pulsar wind nebulae and supernova remnants as case studies for the XIPE configuration and also discuss possible improvements by coupling the detector with advanced optics that have a finer angular resolution and larger effective areas to study extended objects with more detail.

  7. R&D studies of a RICH detector using pressurized C$_{4}$F$_{8}$O radiator gas and a CsI-based gaseous photon detector

    CERN Document Server

    Agócs, A.G; Barnaföldi, G.G; Bellwied, R; Bencédi, G; Bencze, G; Berényi, D; Boldizsár, L; Chattopadhyay, S; Chinellato, D.D; Cindolo, F; Das-Bose, L; Das, D; Das, K; De Cataldo, G; Di Bari, D; Di Mauro, A; Futó, E; Garcia, E; Hamar, G; Harton, A; Jimenez, R.T; Kim, D.W; Kim, J.S; Knospe, A; Kovacs, L; Lévai, P; Markert, C; Martinengo, P; Molnar, L; Nappi, E; Olah, L; Paic, G; Pastore, C; Patino, M.E; Peskov, V; Pinsky, L; Piuz, F; Pochybova, S; Sgura, I; Sinha, T; Song, J; Timmins, A; Van Beelen, J.B; Varga, D; Volpe, G; Weber, M; Xaplanteris, L; Yi, J; Yoo, I.-K

    2013-01-01

    We report on studies of layout and performance of a new Ring Imaging Cherenkov detector using for the fi rst time pressurized C 4 F 8 O radiator gas and a photon detector consisting of a MWPC equipped with a CsI photocathode. In particular, we present here the results of beam tests of a MWPC having an adjustable anode – cathode gap, aiming at the optimization of single photoelectron detection and Cherenkov angle resolution. This system was proposed as a Very High Momentum Particle Identi fi cation (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identi fi cation in the momentum range 5 – 25 GeV/c.

  8. Test beam studies of Gas Electron Multiplier (GEM) detectors for the upgrade of CMS endcap muon system

    CERN Document Server

    Sharma, Ram Krishna

    2017-01-01

    The High Luminosity LHC (HL-LHC) will provide exceptional high instantaneous and integrated luminosity. The forward region $\\mid \\eta \\mid \\geq 1.5$ of the CMS detector will face extremely high particle rates in tens of $KHz/cm^{2}$ and hence it will affect the momentum resolution and longevity of the muon detectors. To overcome these issues the CMS collaboration has decided to install new large size rate capable Triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The first set of Triple GEM detectors will be installed in the GE1/1 region $(1.5 \\leq \\eta \\leq 2.2)$ of muon endcap during the LS2 of the LHC and the next one will be installed in the GE2/1 region $(1.6 \\leq \\eta \\leq 2.5)$, during the LS3. Towards this goal, full-size CMS Triple GEM prototype chambers have been fabricated and put under the test beam at the CERN SPS test beam facility. The GEM detectors were operated with two gas mixtures $Ar/CO_{2}$ (70/30) and $Ar/CO_{2}/CF_{4}$ (40/15/45). In 2014 and 2016, ...

  9. Analysis of JKT01 Neutron Flux Detector Measurements In RSG-GAS Reactor Using LabVIEW

    Science.gov (United States)

    Rokhmadi; Nur Rachman, Agus; Sujarwono; Taryo, Taswanda; Sunaryo, Geni Rina

    2018-02-01

    The RSG-GAS Reactor, one of the Indonesia research reactors and located in Serpong, is owned by the National Nuclear Energy Agency (BATAN). The RSG-GAS reactor has operated since 1987 and some instrumentation and control systems are considered to be degraded and ageing. It is therefore, necessary to evaluate the safety of all instrumentation and controls and one of the component systems to be evaluated is the performance of JKT01 neutron flux detector. Neutron Flux Detector JKT01 basically detects neutron fluxes in the reactor core and converts it into electrical signals. The electrical signal is then forwarded to the amplifier (Amplifier) to become the input of the reactor protection system. One output of it is transferred to the Main Control Room (RKU) showing on the analog meter as an indicator used by the reactor operator. To simulate all of this matter, a program to simulate the output of the JKT01 Neutron Flux Detector using LabVIEW was developed. The simulated data is estimated using a lot of equations also formulated in LabVIEW. The calculation results are also displayed on the interface using LabVIEW available in the PC. By using this simulation program, it is successful to perform anomaly detection experiments on the JKT01 detector of RSG-GAS Reactor. The simulation results showed that the anomaly JKT01 neutron flux using electrical-current-base are respectively, 1.5×,1.7× and 2.0×.

  10. Analysis of neonicotinoids by gas chromatography coupled to nuclide 63Ni - Electron Capture Detector - GC/ECD

    International Nuclear Information System (INIS)

    Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V.

    2015-01-01

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C 9 H 10 ClN 5 O 2 ), clothianidin (C 6 H 8 ClN 5 O 2 S) and thiamethoxam (C 8 H 10 ClN 5 O 3 S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide 63 Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources 63 Ni within carrier gas N 2 . The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  11. Analysis of neonicotinoids by gas chromatography coupled to nuclide {sup 63}Ni - Electron Capture Detector - GC/ECD

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V., E-mail: priscilaoamaral@gmail.com, E-mail: claudio.leao@usp.br, E-mail: marceloredigolo@gmail.com, E-mail: caike1995@gmail.com, E-mail: ovega@ipen.bremails [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C{sub 9}H{sub 10}ClN{sub 5}O{sub 2}), clothianidin (C{sub 6}H{sub 8}ClN{sub 5}O{sub 2}S) and thiamethoxam (C{sub 8}H{sub 10}ClN{sub 5}O{sub 3}S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide {sup 63}Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources {sup 63}Ni within carrier gas N{sub 2}. The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  12. Cherenkov Detector for Beam Quality Measurement

    CERN Document Server

    AUTHOR|(CDS)2078842

    2016-01-01

    A new detector to measure the machine induced background at larger radiihas been developed and installed in the CMS experiment at LHC. Itconsists of 40 modules, each comprising a quartz bar read out by aphotomultiplier. Since Cerenkov radiation is emitted in a forward conearound the charged particle trajectory, these detectors can distinguishthe directions of the machine induced background.The back-end consists of a microTCA readout with excellent time resolution.The performance of the detector modules measured in several test-beamcampaigns will be reported. The installation in CMS will be described, andfirst results about operating the detector during data taking will begiven.

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

    CERN Document Server

    Bergström, D; Carlson, P J; Francke, T; Grinstein, S; Weber, N; Suffert, Martin; Hof, M; Kremer, J; Menn, W; Simon, M; Stephens, S A; Ambriola, M; Bellotti, R; Cafagna, F; Castellano, M G; 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, Guido; Schiavon, R P; Vacchi, A; Zampa, N; Mitchell, J W; Ormes, J F; Streitmatter, R E; Bravar, U; Stochaj, S J

    2001-01-01

    A RICH counter using a gas radiator of C/sub 4/F/sub 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 our 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 beta approximately=1 charge one particles, an average of 12 photoelectrons per event were detected. The reconstructed Cherenkov angle of 50 mrad for a beta approximately=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 u...

  14. Front-end Intelligence for triggering and local track recognition in Gas Pixel Detectors

    CERN Document Server

    Hessey, NP; The ATLAS collaboration; van der Graaf, H; Vermeulen, J; Jansweijer, P; Romaniouk, A

    2012-01-01

    The combination of gaseous detectors with pixel readout chips gives unprecedented hit resolution (improving from O(100 um) for wire chambers to 10 um), as well as high-rate capability, low radiation length and giving in addition angular information on the local track. These devices measure individually every electron liberated by the passage of a charged particle, leading to a large quantity of data to be read out. Typically an external trigger is used to start the read-out. We are investigating the addition of local intelligence to the pixel read-out chip. A first level of processing detects the passage of a particle through the gas volume, and accurately determines the time of passage. A second level measures in an approximate but fast way the tilt-angle of the track. This can be used to trigger a third stage in which all hits associated to the track are processed locally to give a least-squares-fit to the track. The chip can then send out just the fitted track parameters instead of the individual electron ...

  15. Modular data acquisition system and its use in gas-filled detector readout at ESRF

    International Nuclear Information System (INIS)

    Sever, F.; Epaud, F.; Poncet, F.; Grave, M.; Rey-Bakaikoa, V.

    1996-01-01

    Since 1992, 18 ESRF beamlines are open to users. Although the data acquisition requirements vary a lot from one beamline to another, we are trying to implement a modular data acquisition system architecture that would fit with the maximum number of acquisition projects at ESRF. Common to all of these systems are large acquisition memories and the requirement to visualize the data during an acquisition run and to transfer them quickly after the run to safe storage. We developed a general memory API handling the acquisition memory and its organization and another library that provides calls for transferring the data over TCP/IP sockets. Interesting utility programs using these libraries are the open-quote online display close-quote program and the open-quote data transfer close-quote program. The data transfer program as well as an acquisition control program rely on our well-established open-quote device server model close-quote, which was originally designed for the machine control system and then successfully reused in beamline control systems. In the second half of this paper, the acquisition system for a 2D gas-filled detector is presented, which is one of the first concrete examples using the proposed modular data acquisition architecture. copyright 1996 American Institute of Physics

  16. Modular data acquisition system and its use in gas-filled detector readout at ESRF

    Science.gov (United States)

    Sever, F.; Epaud, F.; Poncet, F.; Grave, M.; Rey-Bakaikoa, V.

    1996-09-01

    Since 1992, 18 ESRF beamlines are open to users. Although the data acquisition requirements vary a lot from one beamline to another, we are trying to implement a modular data acquisition system architecture that would fit with the maximum number of acquisition projects at ESRF. Common to all of these systems are large acquisition memories and the requirement to visualize the data during an acquisition run and to transfer them quickly after the run to safe storage. We developed a general memory API handling the acquisition memory and its organization and another library that provides calls for transferring the data over TCP/IP sockets. Interesting utility programs using these libraries are the `online display' program and the `data transfer' program. The data transfer program as well as an acquisition control program rely on our well-established `device server model', which was originally designed for the machine control system and then successfully reused in beamline control systems. In the second half of this paper, the acquisition system for a 2D gas-filled detector is presented, which is one of the first concrete examples using the proposed modular data acquisition architecture.

  17. Development of microstrip gas chamber and application to imaging gamma-ray detector

    International Nuclear Information System (INIS)

    Tanimori, T.; Minami, S.; Nagae, T.; Takahashi, T.; Miyagi, T.

    1992-07-01

    We have developed Microstrip Gas Chamber (MSGC) by using Multi-Chip technology which enables high-density assembly of bare LSI chips on a silicon board. Our MSGC was operated steadily with ∼ 10 3 gain more than one week. An energy resolution of 15% (FWHM) for 5.9 keV X-ray of 55 Fe was obtained. With very thin polyimide substrate of 16 μm thickness, two interesting phenomena were observed; one is a strong dependence of gains on the back plane potential, and the other is little time variation of gains. New type of MSGC with a guarding mask of a thin polyimide layer on the cathode edges has been examined to reduce incidental electrical discharges between anode and cathode strips. Furthermore, new approach to reduce the resistivity of the substrate has been examined. By these approaches, the stability of the high gain operation of ∼ 10 4 has been drastically improved. In addition, we discuss the possibility of the application of MSGC to the coded mask X-ray imaging detector for astrophysics. (author)

  18. VHMPID RICH prototype using pressurized C{sub 4}F{sub 8}O radiator gas and VUV photon detector

    Energy Technology Data Exchange (ETDEWEB)

    Acconcia, T.V. [UNICAMP, University of Campinas, Campinas (Brazil); Agócs, A.G. [Wigner RCP of the HAS, Budapest (Hungary); Barile, F. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); Barnaföldi, G.G. [Wigner RCP of the HAS, Budapest (Hungary); Bellwied, R. [University of Houston, Houston (United States); Bencédi, G. [Wigner RCP of the HAS, Budapest (Hungary); Bencze, G., E-mail: Gyorgy.Bencze@cern.ch [Wigner RCP of the HAS, Budapest (Hungary); Berényi, D.; Boldizsár, L. [Wigner RCP of the HAS, Budapest (Hungary); Chattopadhyay, S. [Saha Institute, Kolkata (India); Chinellato, D.D. [University of Houston, Houston (United States); Cindolo, F. [University of Salerno, Salerno (Italy); Cossyleon, K. [Chicago State University, Chicago, IL (United States); Das, D.; Das, K.; Das-Bose, L. [Saha Institute, Kolkata (India); Dash, A.K. [UNICAMP, University of Campinas, Campinas (Brazil); D' Ambrosio, S. [University of Salerno, Salerno (Italy); De Cataldo, G. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); De Pasquale, S. [University of Salerno, Salerno (Italy); and others

    2014-12-11

    A small-size prototype of a new Ring Imaging Cherenkov (RICH) detector using for the first time pressurized C4F8O radiator gas and a photon detector consisting of MWPC equipped with a CsI photocathode has been built and tested at the PS accelerator at CERN. It contained all the functional elements of the detector proposed as Very High Momentum Particle Identification (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identification in the momentum range starting from 5 potentially up to 25 GeV/c. In the paper the equipment and its elements are described and some characteristic test results are shown.

  19. Development of high pressure-high vacuum-high conductance piston valve for gas-filled radiation detectors

    International Nuclear Information System (INIS)

    Prasad, D N; Ayyappan, R; Kamble, L P; Singh, J P; Muralikrishna, L V; Alex, M; Balagi, V; Mukhopadhyay, P K

    2008-01-01

    Gas-filled radiation detectors need gas filling at pressures that range from few cms of mercury to as high as 25kg/cm 2 at room temperature. Before gas-filling these detectors require evacuation to a vacuum of the order of ∼1 x 10 -5 mbar. For these operations of evacuation and gas filling a system consisting of a vacuum pump with a high vacuum gauge, gas cylinder with a pressure gauge and a valve is used. The valve has to meet the three requirements of compatibility with high-pressure and high vacuum and high conductance. A piston valve suitable for the evacuation and gas filling of radiation detectors has been designed and fabricated to meet the above requirements. The stainless steel body (80mmx160mm overall dimensions) valve with a piston arrangement has a 1/2 inch inlet/outlet opening, neoprene/viton O-ring at piston face and diameter for sealing and a knob for opening and closing the valve. The piston movement mechanism is designed to have minimum wear of sealing O-rings. The valve has been hydrostatic pressure tested up to 75bars and has Helium leak rate of less than 9.6x10 -9 m bar ltr/sec in vacuum mode and 2x10 -7 mbar ltr/sec in pressure mode. As compared to a commercial diaphragm valve, which needed 3 hours to evacuate a 7 litre chamber to 2.5x10 -5 mbar, the new valve achieved vacuum 7.4x10 -6 mbar in the same time under the same conditions

  20. Effective ionization coefficients, electron drift velocities, and limiting breakdown fields for gas mixtures of possible interest to particle detectors

    International Nuclear Information System (INIS)

    Datskos, P.G.

    1991-01-01

    We have measured the gas-density, N, normalized effective ionization coefficient, bar a/N, and the electron drift velocity, w, as a function of the density-reduced electric field, E/N, and obtained the limiting, (E/N) lim , value of E/N for the unitary gases Ar, CO 2 , and CF 4 , the binary gas mixtures CO 2 :Ar (20: 80), CO 2 :CH 4 (20:80), and CF 4 :Ar (20:80), and the ternary gas mixtures CO 2 :CF 4 :Ar (10:10:80) and H 2 O: CF 4 :Ar (2:18:80). Addition of the strongly electron thermalizing gas CO 2 or H 2 O to the binary mixture CF 4 :Ar (1)''cools'' the mixture (i.e., lowers the electron energies), (2) has only a small effect on the magnitude of w(E/N) in the E/N range employed in the particle detectors, and (3) increases bar a/N for E/N ≥ 50 x 10 -17 V cm 2 . The increase in bar a/N, even though the electron energies are lower in the ternary mixture, is due to the Penning ionization of CO 2 (or H 2 O) in collisions with excited Ar* atoms. The ternary mixtures -- being fast, cool, and efficient -- have potential for advanced gas-filled particle detectors such as those for the SCC muon chambers. 17 refs., 8 figs., 1 tab

  1. Error in measuring radon in soil gas by means of passive detectors

    International Nuclear Information System (INIS)

    Tanner, A.B.

    1991-01-01

    Passive detection of radon isotopes depends on diffusion of radon atoms from the sites of their generation to the location of the detecting or collecting device. Because some radon decays en route to a passive detector in soil, the radon concentration measured by the detector must be less than the concentration in those soil pores where it is undiminished by diffusion to the detector cavity. The true radon concentration may be significantly underestimated in moist soils. (author)

  2. Plastic scintillation dosimetry: comparison of three solutions for the Cerenkov challenge

    Energy Technology Data Exchange (ETDEWEB)

    Liu, P Z Y; Suchowerska, N; Lambert, J; Abolfathi, P; McKenzie, D R, E-mail: pliu@physics.usyd.edu.au [School of Physics, University of Sydney, NSW 2006 (Australia)

    2011-09-21

    In scintillation dosimetry, a Cerenkov background signal is generated when a conventional fibre optic is exposed to radiation produced by a megavoltage linear accelerator. Three methods of measuring dose in the presence of Cerenkov background are compared. In the first method, a second background fibre is used to estimate the Cerenkov signal in the signal fibre. In the second method, a colour camera is used to measure the combined scintillation and Cerenkov light in two wavelength ranges and a mathematical process is used to extract the scintillation signal. In the third method, a hollow air core light guide is used to carry the scintillation signal through the primary radiation field. In this paper, the strengths and weaknesses of each dosimetry system are identified and recommendations for the optimum method for common clinical dosimetry situations are made.

  3. Observations of visual sensations produced by Cerenkov radiation from high-energy electrons

    International Nuclear Information System (INIS)

    Steidley, K.D.; Eastman, R.M.; Stabile, R.J.

    1989-01-01

    Ten cancer patients whose eyes were therapeutically irradiated with 6-18 MeV electrons reported visual light sensations. Nine reported seeing blue light and one reported seeing white light. Controls reported seeing no light. Additionally, tests with patients ruled out the x-ray contamination of the electron beam as being important. The photon yield due to Cerenkov radiation produced by radium and its daughters for both electrons and gamma rays was calculated; it was found to account for a turn-of-the-century human observation of the radium phosphene. We conclude that the dominant mechanism of this phosphene is Cerenkov radiation, primarily from betas. From our own patient data, based on the color seen and the Cerenkov production rates, we conclude that the dominant mechanism is Cerenkov radiation and that high-energy electrons are an example of particle induced visual sensations

  4. Cerenkov and radioluminescence imaging of brain tumor specimens during neurosurgery

    Science.gov (United States)

    Spinelli, Antonello Enrico; Schiariti, Marco P.; Grana, Chiara M.; Ferrari, Mahila; Cremonesi, Marta; Boschi, Federico

    2016-05-01

    We presented the first example of Cerenkov luminescence imaging (CLI) and radioluminescence imaging (RLI) of human tumor specimens. A patient with a brain meningioma localized in the left parietal region was injected with 166 MBq of Y90-DOTATOC the day before neurosurgery. The specimens of the tumor removed during surgery were imaged using both CLI and RLI using an optical imager prototype developed in our laboratory. The system is based on a cooled electron multiplied charge coupled device coupled with an f/0.95 17-mm C-mount lens. We showed for the first time the possibility of obtaining CLI and RLI images of fresh human brain tumor specimens removed during neurosurgery.

  5. Cerenkov ring imaging and spectroscopy of charged KSTAR interactions at 11 GeV/c

    International Nuclear Information System (INIS)

    Bird, P.F.

    1988-11-01

    The physics and technology of this new Cerenkov detector are discussed, including materials studies, construction techniques, and resolution measurements. Sources of resolution error are individually identified and measured where possible. The results of all studied indicate that the measurement resolution is understood. This work has led to the adoption of a large scale ring imaging detector as part of a new high energy physics spectrometer, the SLD, at the Stanford Linear Accelerator Center. Results from an amplitude analysis of strange meson final states in K/sup /minus//p → /ovr K/sub 0//π/sup /minus//p interactions are presented. The data derive from a 4 event/nb exposure of the LASS (large Aperture Superconducting Solenoid) spectrometer to an 11 GeV/c K/sup /minus// beam. The data sample consists of /approximately/100,000 vents distributed over the Dalitz plot of the channel. The process is observed to be dominated by the production and decay of natural spin-parity (J/sup P/ = 1/sup /minus//,2 + ,3/sup /minus//,/hor ellipsis/) strange meson states. The data can be understood in terms of a simple model in which the resonant /ovr K*/sup -// are produced predominantly via natural parity exchange in the t channel. The leading K*(890), K 2 *(1430), and K*(1780) resonances are clearly observed and measured, and the underlying spectroscopy is also extracted. Indications of higher mass resonance production are also shown. The observed properties of these states are used to confront current models of quark spectroscopy in strange meson systems. 94 refs., 96 figs., 23 tabs

  6. Observation of lateral substructures in EAS by measurement of the time distribution of atmospheric Cerenkov light

    International Nuclear Information System (INIS)

    Bosia, G.; Navarra, G.; Saavedra, O.

    1975-01-01

    The lateral structure of EAS is derived from the arrival time distribution of atmospheric Cerenkov light assuming a strict correlation between time structure and lateral particle distribution. Results of the Pic du Midi experiment are presented. Substructures in the time distribution of the Cerenkov light can be related to structures in the lateral density distribution of electrons. The frequency (a few %) of substructures can be explained within conventional models of high energy interactions. (orig.) [de

  7. arXiv On the localization properties of an RPWELL gas-avalanche detector

    CERN Document Server

    Moleri, Luca; Coimbra, Artur E. C.; Breskin, Amos; Bressler, Shikma

    2017-10-23

    A study of the localization properties of a single-element Resistive Plate WELL (RPWELL) detector is presented. The detector comprises of a single-sided THick Gaseous Electron Multiplier (THGEM) coupled to a segmented readout anode through a doped silicate-glass plate of 10(10) Ω⋅cm bulk resistivity. Operated in ambient \

  8. A new sub-detector for ATLAS

    CERN Multimedia

    Marco Bruschi

    Since last August, the ATLAS detector family has been joined by a new little member named LUCID, from the acronym "LUminosity Cerenkov Integrating Detector". This may well surprise you if you are already aware that LUCID construction started only in February after its approval by an ATLAS-management mandated review committee. The rapid progress from approval to installation is the result of the close collaboration between groups from Alberta (Canada), INFN Bologna (Italy), Lund (Sweden) and CERN. LUCID is primarily intended to measure the luminosity delivered by the LHC to ATLAS with a systematic uncertainty in the range of a few percent. To achieve such a precision and still meet the demanding installation schedule, the LUCID developers prized simplicity and robustness above all. One of the LUCID vessels while under construction. One can see the aluminum Cerenkov tubes and the photomultiplier mount (plugged into the upper flange). The two fully assembled LUCID vessels seen from the front end elect...

  9. Demonstration of motionless Knudsen pump based micro-gas chromatography featuring micro-fabricated columns and on-column detectors.

    Science.gov (United States)

    Liu, Jing; Gupta, Naveen K; Wise, Kensall D; Gianchandani, Yogesh B; Fan, Xudong

    2011-10-21

    This paper reports the investigation of a micro-gas chromatography (μGC) system that utilizes an array of miniaturized motionless Knudsen pumps (KPs) as well as microfabricated separation columns and optical detectors. A prototype system was built to achieve a flow rate of 1 mL min(-1) and 0.26 mL min(-1) for helium and dry air, respectively, when they were used as carrier gas. This system was then employed to evaluate GC performance compromises and demonstrate the ability to separate and detect gas mixtures containing analytes of different volatilities and polarities. Furthermore, the use of pressure programming of the KP array was demonstrated to significantly shorten the analysis time while maintaining a high detection resolution. Using this method, we obtained a high resolution detection of 5 alkanes of different volatilities within 5 min. Finally, we successfully detected gas mixtures of various polarities using a tandem-column μGC configuration by installing two on-column optical detectors to obtain complementary chromatograms.

  10. GEM gas detectors for soft X-ray imaging in fusion devices with neutron–gamma background

    Energy Technology Data Exchange (ETDEWEB)

    Pacella, Danilo, E-mail: danilo.pacella@enea.it [Associazione EURATOM-ENEA, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Romano, Afra; Gabellieri, Lori [Associazione EURATOM-ENEA, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Murtas, Fabrizio [Istituto Nazionale di Fisica Nucleare, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Mazon, Didier [Association EURATOM-CEA, CEA Cadarache, DSM/IRFM, 13108 St. Paul Lez Durance Cedex (France)

    2013-08-21

    A triple gas electron multiplier (GEM) detector has been built and characterized in a collaboration between ENEA, INFN and CEA to develop a soft X-ray imaging diagnostic for magnetic fusion plasmas. It has an active area of 5×5 cm{sup 2}, 128 pixels and electronics in counting mode. Since burning plasma experiments will have a very large background of radiation, this prototype has been tested with contemporary X-ray, neutron and gamma irradiation, to study the detection efficiencies, and the discrimination capabilities. The detector has been preliminarily characterized under DD neutron irradiation (2.45 MeV) up to 2.2×10{sup 6} n/s on the detector active area, showing a detection efficiency of about 10{sup −4}, while the detection efficiency of X-rays is more than three orders of magnitude higher. The detector has been also tested under DT neutron flux (14 MeV) up to 2.8×10{sup 8} n/s on the whole detector, with a detection efficiency of about 10{sup −5}. The calibration of the γ-rays detection has been done by means of a source of {sup 60}Co (gamma rays of energy 1.17 MeV and 1.33 MeV) and the detection efficiency was found of the order of 10{sup −4}. Thanks to the adjustable gain of the detector and the discrimination threshold of the electronics, it is possible to minimize the sensitivity to neutrons and gamma, and discriminate the X-ray signals even with very high radiative background.

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

    Science.gov (United States)

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

    2016-10-01

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

  12. Muon Chamber Endcap Upgrade of the CMS Experiment with Gas Electron Multiplier (GEM) Detectors and their Performance

    CERN Document Server

    Gola, Mohit

    2017-01-01

    As the CERN LHC is heading towards a high luminosity phase a very high flux is expected in the endcaps of the CMS Detector. The presence of muons in collision events can be due to rare or new physics so it is important to maintain the high trigger efficiency of the CMS muon system. The CMS Collaboration has proposed to instrument the high-eta region (1.6 lt IetaI lt 2.2) of the muon endcaps with Gas Electron Multiplier (GEM) detectors, referred to as GE1/1 chambers, during the LS2. This technology will help in maintaining optimum trigger performance with maximum selection efficiency of muons even in a high flux environment. We describe plans for a Slice Test to installa few GE1/1 chambers covering 50 degrees in azimuthal angle within the CMS detector in 2017, with subsequent operation during the current Run 2 of the LHC. We show the performance of the GE1/1 chambers to be installed during the slice test, specifically GEM foil leakage currents, chamber gas volume integrity, high voltage circuit performanc...

  13. Study of the physical processes involved in the operating mode of the micro-strips gas detector Micromegas

    International Nuclear Information System (INIS)

    Barouch, G.

    2001-04-01

    Micromegas is a micro-strip gaseous detector invented in 1996. It consists of two volumes of gas separated by a micro-mesh. The first volume of gas, 3 mm thick, is used to liberate ionization electrons from the incident charged particle. In the second volume, only 100 μm thick, an avalanche phenomenon amplifies the electrons produced in the first volume. Strips printed on an insulating substrate collect the electrons from the avalanche. The geometrical configuration of Micromegas showed many advantages. The short anode-cathode distance combined with a high granularity provide high rate capabilities due to a fast collection of ions produced during the avalanche development. Moreover, the possibility to localize the avalanche with strips printed about every hundreds of micrometers allows to measure the position of the incident particle with a good resolution. In this work, experimental tests of Micromegas are presented along with detailed Monte Carlo simulations used to understand and optimize the detector's performances. The prototypes were tested several times at the PS accelerator at CERN. The analysis of the date showed a stable and efficient behavior of Micromegas combined with an excellent space resolution. In fact, spatial resolutions of less than 15 μm were obtained. In parallel with the in-beam tests, several simulations have been developed in order to gain a better understanding of the detector's response. (author)

  14. Detectors for alpha particles and X-rays operating in ambient air in pulse counting mode and/or with gas amplification

    CERN Document Server

    Charpak, Georges; Breuil, P; Peskov, Vladimir

    2008-01-01

    Ionization chambers working in ambient air in current detection mode are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and cetera. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification. . To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of 1. The second type alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10E4). A detailed comparison between these two detectors is given as well as comparison with the commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible ap...

  15. Evaluation of the Electronic Bubbler Gas Monitoring System for High Flow in the BaBar Detector

    International Nuclear Information System (INIS)

    Little, Angela

    2003-01-01

    We evaluated the gas monitoring system in the Instrumented Flux Return (IFR) portion of the BaBar detector at the Stanford Linear Accelerator Center (SLAC) to determine its suitability for flows greater than 80 cc/min. Future modifications to the IFR involve particle detectors with a higher gas flow rate than currently in use. Therefore, the bubbler system was tested to determine if it can handle high flow rates. Flow rates between 80 and 240 cc/min were analyzed through short term calibration and long term stability tests. The bubbler system was found to be reliable for flow rates between 80 and 160 cc/min. For flow rates between 200 and 240 cc/min, electronic instabilities known as baseline spikes caused a 10-20% error in the bubble rate. An upgrade would be recommended for use of the bubbler system at these flow rates. Since the planned changes in the IFR will require a maximum flow of 150 cc/min, the bubbler system can sufficiently handle the new gas flow rates

  16. SU-F-J-46: Feasibility of Cerenkov Emission for Absorption Spectroscopy

    International Nuclear Information System (INIS)

    Oraiqat, I; Rehemtulla, A; Lam, K; Ten Haken, R; El Naqa, I; Clarke, R

    2016-01-01

    Purpose: Cerenkov emission (CE) is a promising tool for online tumor microenvironment interrogation and targeting during radiotherapy. In this work, we utilize CE generated during radiotherapy as a broadband excitation source for real-time absorption spectroscopy. We demonstrate the feasibility of CE spectroscopy using a controlled experiment of materials with known emission/absorption properties. Methods: A water tank is irradiated with 20 MeV electron beam to induce Cerenkov emission. Food coloring dyes (Yellow #5, Red #40, and Blue #1), which have known emission/absorption properties were added to the water tank with increasing concentration (1 drop (0.05 mL), 2 drops, and 4 drops from a dispenser bottle). The signal is collected using a condensing lens which is coupled into a 20m optical fiber that is fed into a spectrometer that measures the emitted spectra. The resulting spectra from water/food coloring dye solutions were normalized by the reference spectrum, which is the Cerenkov spectrum of pure water, correcting for both the nonlinearity of the broadband Cerenkov emission spectrum as well as the non-uniform spectral response of the spectrometer. The emitted spectra were then converted into absorbance and their characteristics were analyzed. Results: The food coloring dye had a drastic change on the Cerenkov emission, shifting its wavelength according to its visible color. The collected spectra showed various absorbance peaks which agrees with tabulated peak positions of the dyes added within 0.3% for yellow, 1.7% for red, and 0.16% for blue. The CE peak heights proportionally increased as the dye concentration is increased. Conclusion: This work shows the potential for real-time functional spectroscopy using Cerenkov emission during radiotherapy. It was demonstrated that molecule identification as well as relative concentration can be extracted from the Cerenkov emission color shift.

  17. SU-E-T-238: Monte Carlo Estimation of Cerenkov Dose for Photo-Dynamic Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chibani, O; Price, R; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Eldib, A [Fox Chase Cancer Center, Philadelphia, PA (United States); University Cairo (Egypt); Mora, G [de Lisboa, Codex, Lisboa (Portugal)

    2014-06-01

    Purpose: Estimation of Cerenkov dose from high-energy megavoltage photon and electron beams in tissue and its impact on the radiosensitization using Protoporphyrine IX (PpIX) for tumor targeting enhancement in radiotherapy. Methods: The GEPTS Monte Carlo code is used to generate dose distributions from 18MV Varian photon beam and generic high-energy (45-MV) photon and (45-MeV) electron beams in a voxel-based tissueequivalent phantom. In addition to calculating the ionization dose, the code scores Cerenkov energy released in the wavelength range 375–425 nm corresponding to the pick of the PpIX absorption spectrum (Fig. 1) using the Frank-Tamm formula. Results: The simulations shows that the produced Cerenkov dose suitable for activating PpIX is 4000 to 5500 times lower than the overall radiation dose for all considered beams (18MV, 45 MV and 45 MeV). These results were contradictory to the recent experimental studies by Axelsson et al. (Med. Phys. 38 (2011) p 4127), where Cerenkov dose was reported to be only two orders of magnitude lower than the radiation dose. Note that our simulation results can be corroborated by a simple model where the Frank and Tamm formula is applied for electrons with 2 MeV/cm stopping power generating Cerenkov photons in the 375–425 nm range and assuming these photons have less than 1mm penetration in tissue. Conclusion: The Cerenkov dose generated by high-energy photon and electron beams may produce minimal clinical effect in comparison with the photon fluence (or dose) commonly used for photo-dynamic therapy. At the present time, it is unclear whether Cerenkov radiation is a significant contributor to the recently observed tumor regression for patients receiving radiotherapy and PpIX versus patients receiving radiotherapy only. The ongoing study will include animal experimentation and investigation of dose rate effects on PpIX response.

  18. SU-F-J-46: Feasibility of Cerenkov Emission for Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oraiqat, I; Rehemtulla, A; Lam, K; Ten Haken, R; El Naqa, I [University of Michigan, Radiation Oncology, Ann Arbor, MI (United States); Clarke, R [University of Michigan, Physics Department, Ann Arbor, MI (United States)

    2016-06-15

    Purpose: Cerenkov emission (CE) is a promising tool for online tumor microenvironment interrogation and targeting during radiotherapy. In this work, we utilize CE generated during radiotherapy as a broadband excitation source for real-time absorption spectroscopy. We demonstrate the feasibility of CE spectroscopy using a controlled experiment of materials with known emission/absorption properties. Methods: A water tank is irradiated with 20 MeV electron beam to induce Cerenkov emission. Food coloring dyes (Yellow #5, Red #40, and Blue #1), which have known emission/absorption properties were added to the water tank with increasing concentration (1 drop (0.05 mL), 2 drops, and 4 drops from a dispenser bottle). The signal is collected using a condensing lens which is coupled into a 20m optical fiber that is fed into a spectrometer that measures the emitted spectra. The resulting spectra from water/food coloring dye solutions were normalized by the reference spectrum, which is the Cerenkov spectrum of pure water, correcting for both the nonlinearity of the broadband Cerenkov emission spectrum as well as the non-uniform spectral response of the spectrometer. The emitted spectra were then converted into absorbance and their characteristics were analyzed. Results: The food coloring dye had a drastic change on the Cerenkov emission, shifting its wavelength according to its visible color. The collected spectra showed various absorbance peaks which agrees with tabulated peak positions of the dyes added within 0.3% for yellow, 1.7% for red, and 0.16% for blue. The CE peak heights proportionally increased as the dye concentration is increased. Conclusion: This work shows the potential for real-time functional spectroscopy using Cerenkov emission during radiotherapy. It was demonstrated that molecule identification as well as relative concentration can be extracted from the Cerenkov emission color shift.

  19. Gas delivery system and beamline studies for the test beam facility of the Collider Detector at Fermilab

    International Nuclear Information System (INIS)

    Franke, H.G. III.

    1987-12-01

    A fixed-target test beam facility has been designed and constructed at the Meson Test (MT) site to support studies of components of the Collider Detector at Fermi National Accelerator Laboratory (CDF). I assisted in the design and constuction of the test beam facility gas delivery system, and I conducted the initial studies to document the ability of the MT beamline to meet the needs of CDF. Analysis of the preliminary performance data on MT beamline components and beam tunes at required particle energies is presented. Preliminary studies show that the MT beamline has the necessary flexibility to satisfy most CDF requirements now

  20. Gain uniformity experimental study performed on triple-GEM gas detector

    International Nuclear Information System (INIS)

    Dong Liyuan; Qi Huirong; Lu Xinyu; Ouyang Qun; Chen Yuanbo; Li Yuhong

    2012-01-01

    With the application of the two-dimensional GEM gaseous detector in X-ray imaging, the correction method of gain uniformity caused by triple-GEM avalanche structures and electric field uniformity should be studied. The paper reported the study of the triple-GEM detector with effective area 100 mm × 100 mm used the Pad's size of 9.5 mm × 9.5 mm. In the test, 100 readout channels were designed. Results showed that gain remained stable over time; at air flow increases, gain from increases obviously to changes very little. Particularly, triple-GEM's gain uniformity was very good (more than 80%) and the range of energy resolution was from 0.18 to 0.2. To improve gain consistency of results, the difference value revised was obtained to be about 0.1 by the least square method. It provided a better method to improve gain uniformity of GEM detector. (authors)

  1. Moving Forward - Progress on Forward Detectors

    CERN Multimedia

    Grafstrom, P.

    2006-01-01

    You might have been sitting in some meeting hearing about the ATLAS forward detectors. Coming back to your office wanting to learn more you look in the ATLAS TDR’s and disappointingly you find nothing about forward detectors. The explanation is of course that the forward detectors are newcomers in the ATLAS detector arsenal. ATLAS is designed to measure high Pt particles with pseudo rapidities up to 5 which in terms of angles means angles bigger than one degree (0.8 degree to be more accurate). Particles produced with smaller angles close to the beam escape detection. The hole in the forward direction will now partly be filled. Several new detectors have recently been proposed. These detectors are designed for various luminosity measurements but they also have a physics potential in themselves. Closest to the IP there is LUCID (LUminosity measurement using Cerenkov Integrating Detector). LUCID comprises some 170 Cerenkov tubes sitting around the beam pipe at about 17 m away from the IP. The tubes are 1.5 ...

  2. Analysis of benzene, toluene, ethylbenzene and xylenes in soils by headspace and gas chromatography/flame ionization detector

    Directory of Open Access Journals (Sweden)

    Jurandir Pereira Pinto

    2006-02-01

    Full Text Available The constituents of gasoline: benzene, toluene, ethylbenzene and xylenes (BTEX are frequently found in soils due to leaks in fuel storage tanks and they present chronic toxicity. In this work it was developed and validated a methodology of BTEX analysis in soil by gas chromatography/ flame ionization detector and static headspace. The recovery of BTEX in soil samples was evaluated using soils with different textures (sandy and loamy. The analysis method showed good resolution, in a low time of analysis (less than 30 minutes. Limits of quantification of 0.05 mg Kg¯¹ soil for benzene, toluene, ethylbenzene and xylenes are below the guiding values that range from 0.15 to 95 mg Kg¯¹ soil, established to determine soil quality. It was verified that the methodology enables the use of this method for BTEX analysis of soil samples for passive environmental identification of gas stations.

  3. Enhanced counting efficiency of Cerenkov radiation from bismuth-210

    International Nuclear Information System (INIS)

    Peck, G.A.; Smith, J.D.

    1998-01-01

    This paper describes the measurement of 210 Bi by Cerenkov counting in a commercial liquid scintillation counter. The counting efficiency in water is 0.17 counts per second per Becquerel (17%). When the enhancers Triton X-100 (15% v/v) and sodium salicylate (1% m/v) are added to the solution the counting efficiency for 210 Bi increases from 17% to 75%. The 210 Po daughter of 210 Bi causes interference of 0.85 counts per second per Becquerel in the presence of the enhancers but not in water. When 210 Bi and 210 Po are present in secular equilibrium the total counting efficiency is 160%. When 210 Bi and 210 Po are not in secular equilibrium the 210 Po can be removed immediately before counting by plating onto silver foil. The use of the enhancers gives a substantial increase in counting efficiency compared to counting in water. Compared with solutions used in liquid scintillation counting the enhancer solution is inexpensive and can be disposed of without environmental hazard. (author)

  4. Integrated input protection against discharges for Micro Pattern Gas Detectors readout ASICs

    International Nuclear Information System (INIS)

    Fiutowski, T.; Dąbrowski, W.; Koperny, S.; Wiącek, P.

    2017-01-01

    Immunity against possible random discharges inside active detector volume of MPGDs is one of the key aspects that should be addressed in the design of the front-end electronics. This issue becomes particularly critical for systems with high channel counts and high density readout employing the front-end electronics built as multichannel ASICs implemented in modern CMOS technologies, for which the breakdown voltages are in the range of a few Volts. The paper presents the design of various input protection structures integrated in the ASIC manufactured in a 350 nm CMOS process and test results using an electrical circuit to mimic discharges in the detectors.

  5. Detectors for alpha particles and X-rays operating in ambient air in pulse counting mode or/and with gas amplification

    International Nuclear Information System (INIS)

    Charpak, G; Benaben, P; Breuil, P; Peskov, V

    2008-01-01

    Ionization chambers working in ambient air in current detection mode are attractive due to their simplicity and low cost and are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and so on. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification which potentially offers the highest possible sensitivity in applications like alpha particle detection or high energy X-ray photon or electron detection. To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of one (pulse ionization chamber). This detector was readout by a custom made wide -band charge sensitive amplifier able to deal with slow induced signals generated by slow motion of negative and positive ions. The multiwire detector was able to detect alpha particles with an efficiency close to 22%. The second type of an alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10 4 ). This detector can also operate in a cascaded mode or being combined with other detectors, for example with MICROMEGAS. This detector was readout by a conventional charge -sensitive amplifier and was able to detect alpha particles with 100% efficiency. This detector could also detect X-ray photons or fast electrons. A detailed comparison between these two detectors is given as well as a comparison with commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible applications of these new detectors is alpha particle background monitors which, due to their low cost can find wide application not only in houses, but

  6. Design, development and calibration of a radioactive gas (85Kr) detector for continuous environmental monitoring

    International Nuclear Information System (INIS)

    Janardhanan, S.; Swaminathan, N.; John, Jacob; Kutty, K.N.; Wattamwar, S.B.; Gopalan, C.S.; Menezes, C.M.

    1982-01-01

    Design, development and calibration of a scintillation type detector for environmental monitoring of low levels of 85 Kr activity in off-line effluents or plant areas in presence of gamma background are reported. Calibration of the system was done using NBS 85 Kr standard. (author)

  7. Design, development and calibration of a radioactive gas (/sup 85/Kr) detector for continuous environmental monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Janardhanan, S.; Swaminathan, N.; John, J.; Kutty, K.N.; Wattamwar, S.B. (Bhabha Atomic Research Centre, Bombay (India). Health Physics Div.); Gopalan, C.S.; Menezes, C.M. (Bhabha Atomic Research Centre, Bombay (India). Electronics Div.)

    Design, development and calibration of a scintillation type detector for environmental monitoring of low levels of /sup 85/Kr activity in off-line effluents or plant areas in presence of gamma background are reported. Calibration of the system was done using NBS /sup 85/Kr standard.

  8. Analytical modeling of thin film neutron converters and its application to thermal neutron gas detectors

    Energy Technology Data Exchange (ETDEWEB)

    Piscitelli, F; Esch, P Van, E-mail: piscitelli@ill.fr [Institut Laue-Langevin (ILL), 6, Jules Horowitz, 38042 Grenoble (France)

    2013-04-15

    A simple model is explored mainly analytically to calculate and understand the PHS of single and multi-layer thermal neutron detectors and to help optimize the design in different circumstances. Several theorems are deduced that can help guide the design.

  9. A High Position Resolution X-ray Detector: an Edge on Illuminated Capillary Plate Combined with a Gas Amplification Structure

    CERN Document Server

    Iacobaeus, C.; Lund-Jensen, B.; Ostling, J.; Pavlopoulos, P.; Peskov, V.; Tokanai, F.

    2006-01-01

    We have developed and successfully tested a prototype of a new type of high position resolution hybrid X-ray detector. It contains a thin wall lead glass capillary plate converter of X-rays combined with a microgap parallel-plate avalanche chamber filled with gas at 1 atm. The operation of these converters was studied in a wide range of X-ray energies (from 6 to 60 keV) at incident angles varying from 0-90 degree. The detection efficiency, depending on the geometry, photon energy, incident angle and the mode of operation, was between 5-30 percent in a single step mode and up to 50 percent in a multi-layered combination. Depending on the capillary geometry, the position resolution achieved was between 0.050-0.250 mm in digital form and was practically independent of the photon energy or gas mixture. The usual lead glass capillary plates operated without noticeable charging up effects at counting rates of 50 Hz/mm2, and hydrogen treated capillaries up to 10E5 Hz/mm2. The developed detector may open new possibil...

  10. Gas filled prototype of a CdZnTe pixel detector

    International Nuclear Information System (INIS)

    Ramsey, B.; Sharma, D.; Sipila, H.; Gostilo, V.; Loupilov, A.

    2001-01-01

    CdZnTe pixel structures are currently the most promising detectors for the focal planes of hard X-ray telescopes, for astronomical observation in the range 5-100 keV. In Sharma et al. (Proc. SPIE 3765 (1999) 822) and Ramsey et al. (Nucl. Instrum. Methods A 458 (2001) 55) we presented preliminary results on the development of prototype 4x4 CdZnTe imaging detectors operated under vacuum. These pixel detectors were installed inside vacuum chambers on three-stage Peltier coolers providing detector temperatures down to -40 deg. C. A miniature sputter ion pump inside each chamber maintained the necessary vacuum of 10 -5 Torr. At a temperature of -20 deg. C we achieved an FWHM energy resolution of between 2% and 3% at 60 keV and ∼15% at 5.9 keV; however, the dependency on temperature was weak and at +20 deg. C the respective resolutions were 3% and 20%. As the detectors could be operated at room temperature without loss of their good characteristics it was possible to exclude the sputter ion pump and fill the chamber with dry nitrogen instead. We have tested a nitrogen-filled CdZnTe (5x5x1 mm 3 ) prototype having 0.65x0.65 mm 2 readout pads on a 0.75 mm pitch. The interpixel resistance at an applied voltage of 10 V was higher than 50 GΩ and the pixel leakage currents at room temperature with a bias of 200 V between each pad and the common electrode did not exceed 0.8 nA. The pixel detector inside the microassembly, which also contained the input stages of the preamplifiers, was installed on a Peltier cooler to maintain the detector temperature at +20 deg. C. To define real leakage currents of the pixels in their switched-on state we have checked the voltage on the preamplifiers feedback resistors. The resulting currents were 10-50 pA at a detector bias of 500 V. Under test, the typical energy resolution per pixel at +20 deg. C was ∼3% at energy 59.6 keV and ∼20% at energy 5.9 keV, which are similar to the values obtained in the vacuum prototype at room temperature

  11. Split detector

    International Nuclear Information System (INIS)

    Cederstrand, C.N.; Chism, H.R.

    1982-01-01

    A gas analyzer is disclosed which provides a dual channel capability for the simultaneous determination of the presence and concentration of two gases in a stream of sample gas and which has a single infrared source, a single sample cell, two infrared bandpass filters, and two infrared detectors. A separator between the filters and detectors prevents interchange of radiation between the filters. The separator is positioned by fitting it in a slot

  12. Radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Ohata, Shuichi; Takeuchi, Yoji

    1968-10-30

    Herein disclosed is an ionization chamber the airtightness of which can be readily tested. The ionization chamber is characterized in that a small amount of helium gas is filled in the chamber in combination with other ionization gases such as argon gas, xenon gas and the like. Helium leakage from the chamber is measured by a known helium gas sensor in a vacuum vessel. Hence the long term drift of the radiation detector sensitivity may be determined.

  13. Development of a High Sensitivity Digital Cerenkov Viewing Device. Prototype Digital Cerenkov Viewing Device. Field test in Sweden

    International Nuclear Information System (INIS)

    Chen, J.D.; Gerwing, A.F.; Lewis, P.D.; Larsson, M.; Jansson, K.; Lindberg, B.; Sundkvist, E.; Ohlsson, M.

    2002-05-01

    The Swedish and Canadian Safeguards Support Programs have developed a prototype Digital Cerenkov Viewing Device (DCVD) to verify long-cooled spent fuel. The instrument consists of a camera system and a custom portable computer equipped with a liquid crystal and a wearable heads-up display. The camera was coupled to a hardware user interface (HUI) and was operated with a computer program designed to image spent fuel and store the images. Measurements were taken at the CLAB facility on pressurized-water reactor fuel and non-fuel assemblies, a number of boiling-water reactor fuel assemblies, and long-cooled Aagesta fuel assemblies. The camera head, attached to the HUI, a battery-operated computer carried in a backpack and the heads-up display were field tested for portability. The ergonomics of this system is presented in the report. For the examination of long-cooled spent fuel, the camera head was mounted on a bracket that rested on the railing of a moving bridge. The DCVD instrument is approximately 100 times higher in sensitivity than the Mark IVe CVD. The oldest fuel with the lowest burnup at the CLAB facility was positively verified. The measurement capability of this instrument greatly exceeds the verification criteria of 10,000 MWd/t U and 40 years cooling

  14. Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam

    International Nuclear Information System (INIS)

    Lambert, Jamil; Yin Yongbai; McKenzie, David R.; Law, Sue; Suchowerska, Natalka

    2009-01-01

    A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.

  15. Validation of an analytical method for simultaneous high-precision measurements of greenhouse gas emissions from wastewater treatment plants using a gas chromatography-barrier discharge detector system.

    Science.gov (United States)

    Pascale, Raffaella; Caivano, Marianna; Buchicchio, Alessandro; Mancini, Ignazio M; Bianco, Giuliana; Caniani, Donatella

    2017-01-13

    Wastewater treatment plants (WWTPs) emit CO 2 and N 2 O, which may lead to climate change and global warming. Over the last few years, awareness of greenhouse gas (GHG) emissions from WWTPs has increased. Moreover, the development of valid, reliable, and high-throughput analytical methods for simultaneous gas analysis is an essential requirement for environmental applications. In the present study, an analytical method based on a gas chromatograph (GC) equipped with a barrier ionization discharge (BID) detector was developed for the first time. This new method simultaneously analyses CO 2 and N 2 O and has a precision, measured in terms of relative standard of variation RSD%, equal to or less than 6.6% and 5.1%, respectively. The method's detection limits are 5.3ppm v for CO 2 and 62.0ppb v for N 2 O. The method's selectivity, linearity, accuracy, repeatability, intermediate precision, limit of detection and limit of quantification were good at trace concentration levels. After validation, the method was applied to a real case of N 2 O and CO 2 emissions from a WWTP, confirming its suitability as a standard procedure for simultaneous GHG analysis in environmental samples containing CO 2 levels less than 12,000mg/L. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Some properties of Cerenkov radiation due to the finite thickness of the radiator

    International Nuclear Information System (INIS)

    Kobzev, A.P.; Frank, I.M.

    1981-01-01

    The properties of Cerenkov radiation are analyzed for a small radiator thickness. It is shown that the directionality of the radiation, its threshold properties, and also the dependence on the electron energy and radiator thickness differ substantially from the well known characteristics of Cerenkov radiation corresponding to the case of an unlimited particle trajectory in an extended medium. We have experimentally studied the directionality and energy characteristics of radiation excited by electrons in a mica target of thickness 12 400 A at wavelength 4000 A. The experimental results are in good agreement with the calculations

  17. Gas Detectors Performance in CMS and Excited Muon Search Feasibility Study at 14 teV

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00572294; Mahrous, Ayman; Yasein, Mohamed Nabil

    Within the Standard Model(SM) of particle physics, quarks and leptons are understood to be the fundamental particles and Their existence have been verified experimentally. A search for substructure of quarks or study of quark compositeness is carried out with the CMS detector at LHC, using $ 300 fb^{-1} $ of integrated luminosity at a center-of-mass energy$ \\sqrt{s} =14 TeV $. The discovery of excited muons ($ \\mu^{*} $) would be a first indication of lepton compositeness. In the current study, $ \\mu^{*} $ is assumed to be produced via four-fermions contact interactions in association with a muon ($ \\mu $) and to decay via the gauge mediated process $ \\mu^{*} \\to \\mu\\gamma$, yielding a final state with two muons and a photon. Monte Carlo (MC) samples are produced via MadGraph5 and PYTHIA 8 event generators. To simulate the detector response, GEANT4 which interfaced to CMS software was used for full simulation and Delphes was used for fast simulation, assuming the CMS detector configuration. Objects and ev...

  18. Solar Axion search with Micromegas detectors in the CAST Experiment with $^{3}$He as buffer gas

    CERN Document Server

    García, Juan Antonio

    2015-01-01

    Axions are well motivated particles proposed in an extension of the Standard Model (SM) as a solution to the CP problem in strong interactions. On the other hand, there is the category of axion-like particles (ALPs) which appear in diverse extensions of the SM and share the same phenomenology of the axion. Axions and ALPs are hypothetical neutral particles that interact weakly with matter, being candidates to solve the Dark Matter problem. CAST, the CERN Axion Solar Telescope is looking for solar axions since 2003. CAST exploit the helioscope technique using a decommissioned LHC dipole magnet in which solar axions could be reconverted into photons. The magnet is mounted on a movable platform that allows tracking the Sun $\\sim$1.5 hours during sunset and during sunrise. The axion signal would be an excess of X-rays in the detectors located at the magnet bore ends and thus low background detectors are mandatory. Three of the four detectors operating at CAST are of the Micromegas type. The analysis of the data o...

  19. Design of the ATLAS New Small Wheel Gas Distribution System for the Micromegas Detector Modules

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00084094; The ATLAS collaboration; Alexopoulos, Theodoros; Maltezos, Stavros; Vlachos, Sotirios; Karentzos, Efstathios; Koulouris, Aimilianos; Moschovakos, Paris; Koutelieris, Georgios

    2016-01-01

    In this work we present and describe the methodology, the particular calculations and simulations accordingly to achieve the appropriate gas flow rates ensuring a uniform gas distribution among the same type of NSW Micromegas modules. The majority of the components used are in large multiplicity so space saving criteria is taking into account and simplicity on the performance with respect to the total cost as well. An appropriate simulation program has been developed for studying the overall gas system determining the gauge pressure, flow rate in the crucial points and branches, respectively. Moreover, an overall prototype configuration, implemented at the NTUA laboratory and based on the Lock-in Amplifier technique to be used in conjunction with the gas leak test via the FRL method is presented. The obtained performances, by means of sensitivity and S/N ratio improvement, are also discussed.

  20. Total OH reactivity measurements using a new fast Gas Chromatographic Photo-Ionization Detector (GC-PID

    Directory of Open Access Journals (Sweden)

    V. Sinha

    2012-12-01

    Full Text Available The primary and most important oxidant in the atmosphere is the hydroxyl radical (OH. Currently OH sinks, particularly gas phase reactions, are poorly constrained. One way to characterize the overall sink of OH is to measure directly the ambient loss rate of OH, the total OH reactivity. To date, direct measurements of total OH reactivity have been either performed using a Laser-Induced Fluorescence (LIF system ("pump-and-probe" or "flow reactor" or the Comparative Reactivity Method (CRM with a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS. Both techniques require large, complex and expensive detection systems. This study presents a feasibility assessment for CRM total OH reactivity measurements using a new detector, a Gas Chromatographic Photoionization Detector (GC-PID. Such a system is smaller, more portable, less power consuming and less expensive than other total OH reactivity measurement techniques.

    Total OH reactivity is measured by the CRM using a competitive reaction between a reagent (here pyrrole with OH alone and in the presence of atmospheric reactive molecules. The new CRM method for total OH reactivity has been tested with parallel measurements of the GC-PID and the previously validated PTR-MS as detector for the reagent pyrrole during laboratory experiments, plant chamber and boreal field studies. Excellent agreement of both detectors was found when the GC-PID was operated under optimum conditions. Time resolution (60–70 s, sensitivity (LOD 3–6 s−1 and overall uncertainty (25% in optimum conditions for total OH reactivity were similar to PTR-MS based total OH reactivity measurements. One drawback of the GC-PID system was the steady loss of sensitivity and accuracy during intensive measurements lasting several weeks, and a possible toluene interference. Generally, the GC-PID system has been shown to produce closely comparable results to the PTR-MS and thus in suitable environments (e.g. forests it

  1. Overview of the data acquisition electronics system design for the SLAC Linear Collider Detector (SLD)

    International Nuclear Information System (INIS)

    Larsen, R.S.

    1985-09-01

    The SLD Detector will contain five major electronics subsystems: Vertex, Drift, Liquid Argon Calorimeter, Cerenkov Ring Imaging, and Warm Iron Calorimeter. To implement the approximately 170,000 channels of electronics, extensive miniaturization and heavy use of multiplexing techniques are required. Design criteria for each subsystem, overall system architecture, and the R and D program are described

  2. Determinação de isotiocianato de benzila em Carica papaya utilizando cromatografia gasosa com detectores seletivos Determination of benzyl isothiocyanate in Carica papaya using gas chromatography with selectives detectors

    Directory of Open Access Journals (Sweden)

    Izabela Miranda de Castro

    2008-01-01

    Full Text Available In the present work, a method was developed and validated for the quantification of benzyl isothiocyanate (BITC in the fruits of Carica papaya. The quantification of this compound was carried out by gas chromatography (GC with selective detectors - nitrogen phosphorus detector (NPD and flame photometric detector (FPD. The performance of these detectors showed a higher sensitivity of the NPD with a broader linear range of detection. The LOD/LOQ were 0.038/0.100 µg/mL for NPD and 5.78/19.29 µg/mL for FPD. The recovery of the method for BITC was 90,64%. An average value of BITC concentration in all the analyzed samples was 16,23 µg BITC/g.

  3. Determination of N-containing halogenated natural products using gas chromatography in combination of a nitrogen-phosphorus-detector

    Energy Technology Data Exchange (ETDEWEB)

    Melcher, J.; Vetter, W. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Lebensmittelchemie

    2004-09-15

    In the last few years several nonpolar halogenated natural products (HNPs) such as Q1, MHC-1, BC-2, BC-3, BC-10 were detected at elevated concentrations in marine biota samples. In addition, there are still some abundant peaks of halogenated compounds frequently found in the gas chromatograms of many marine samples which have not yet been identified. Some of the known halogenated natural products (Q1, HDBPs including BC-10, bromoindoles) contain N-heterocyclic backbones. Since nitrogen is scarcely found in anthropogenic halogenated compounds, the detection of N-containing halogenated substances may be used as a first indicator for the presence of HNPs in a sample extract. In the presented method we studied the suitability of a nitrogen phosphorous detector (NPD) for quantification of Q1 and the detection of Ncontaining compounds in marine biota. Analyses were accompanied with GC/ECD analyses.

  4. Effect of the Detector Width and Gas Pressure on the Frequency Response of a Micromachined Thermal Accelerometer

    Directory of Open Access Journals (Sweden)

    Johann Courteaud

    2011-05-01

    Full Text Available In the present work, the design and the environmental conditions of a micromachined thermal accelerometer, based on convection effect, are discussed and studied in order to understand the behavior of the frequency response evolution of the sensor. It has been theoretically and experimentally studied with different detector widths, pressure and gas nature. Although this type of sensor has already been intensively examined, little information concerning the frequency response modeling is currently available and very few experimental results about the frequency response are reported in the literature. In some particular conditions, our measurements show a cut-off frequency at −3 dB greater than 200 Hz. By using simple cylindrical and planar models of the thermal accelerometer and an equivalent electrical circuit, a good agreement with the experimental results has been demonstrated.

  5. Detector for the liquid carried over in a gas; Detecteur d'entrainement de liquide dans un gaz

    Energy Technology Data Exchange (ETDEWEB)

    Delisle, J P; Eperonnat, P; Lions, N [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1965-07-01

    This report describes an optical detector for the detection of a liquid carried over by a gas. The device is sensitive to a cumulated quantity of liquid equal to a few cubic millimetres and is capable of operating an alarm from a distance. The prototype was constructed and tested as detector for the oil leaking in the argon compressed by a diaphragm compressor. A patent for this apparatus under the number: P.V.954.703, has been deposited on 22.11.1963. (authors) [French] Ce rapport decrit un detecteur optique d'entrainement de liquide dans un gaz, sensible a une quantite cumulee de liquide entraine egale a quelques millimetres cubes. L'appareil peut actionner une alarme a distance. Le prototype a ete construit et essaye comme detecteur de fuites d'huile dans l'argon refoule par un compresseur a membranes. Une demande de brevet a ete deposee pour cet appareil sous le numero: P.V.954.703, le 22.11.1963. (auteur)

  6. A quantification method for peroxyacetyl nitrate (PAN) using gas chromatography (GC) with a non-radioactive pulsed discharge detector (PDD)

    Science.gov (United States)

    Zhang, Lei; Jaffe, Daniel A.; Gao, Xin; McClure, Crystal D.

    2018-04-01

    In this study, we developed a method for continuous PAN measurements by gas chromatography (GC) with a non-radioactive pulsed discharge detector (PDD). Operational parameters were optimized based on the ratio of peak height over baseline noise (P/N ratio). The GC/PDD system was compared with a traditional radioactive electron-capture detector (ECD). In the lab, the method detection limit (MDL) of the new GC/PDD method (9 pptv) was lower than the radioactive GC/ECD method (15 pptv), demonstrating its excellent potential. The MDL of GC/PDD in the field campaign at the Mt. Bachelor Observatory (MBO) was 23 pptv, higher than in the lab. This was caused in part by the decreased slope of the calibration curve resulting from the low air pressure level at MBO. However, the MDL level of GC/PDD at MBO is still low enough for accurate PAN measurements, although special attention should be paid to its application at high-elevation sites. Observations of PAN were conducted at MBO in the summer of 2016 with the GC/PDD system, and provided more evidence of the performance of the system. PAN was found to be highly correlated with CO. The promising performance of GC/PDD which does not require a radioactive source makes it a useful approach for accurate PAN measurements in the field.

  7. Gas proportional detectors with interpolating cathode pad readout for high track multiplicities

    International Nuclear Information System (INIS)

    Yu, Bo.

    1991-12-01

    New techniques for position encoding in very high rate particle and photon detectors will be required in experiments planned for future particle accelerators such as the Superconducting Super Collider and new, high intensity, synchrotron sources. Studies of two interpolating cathode ''pad'' readout systems are described in this thesis. They are well suited for high multiplicity, two dimensional unambiguous position sensitive detection of minimum ionizing particles and heavy ions as well as detection of x-rays at high counting rates. One of the readout systems uses subdivided rows of pads interconnected by resistive strips as the cathode of a multiwire proportional chamber (MWPC). A position resolution of less than 100 μm rms, for 5.4 keV x-rays, and differential non-linearity of 12% have been achieved. Low mass (∼0.6% of a radiation length) detector construction techniques have been developed. The second readout system uses rows of chevron shaped cathode pads to perform geometrical charge division. Position resolution (FWHM) of about 1% of the readout spacing and differential non-linearity of 10% for 5.4 keV x-rays have been achieved. A review of other interpolating methods is included. Low mass cathode construction techniques are described. In conclusion, applications and future developments are discussed. 54 refs

  8. Treatment of Cerenkov radiation from electric and magnetic charges in dispersive and dissipative media

    International Nuclear Information System (INIS)

    Saffouri, M.H.

    1982-07-01

    A rigorous treatment of the problem of Cerenkov radiation from fast moving electric and magnetic charges is presented. This is based on the rigorous solution of Maxwell's equations in a general dispersive medium possessing dielectric and magnetic properties and with, and without, dissipation. It is shown that the fields are completely determined by one scalar function. Expressions for the exact fields are obtained. From the asymptotic fields all the relevant properties of Cerenkov radiation are reproduced. In particular, it is shown that in the absence of dissipation the energy in each mode travels with the phase velocity of that mode. For a dissipative medium the electric field develops a longitudinal component and the energy propagates at an angle to the phase velocity. Application to the case of a Tachyon shows that it must emit Cerenkov radiation in vacuum. An estimate is given for the resulting linear density of emitted radiation. Finally, two suggestions are made for the experimental detection of magnetic charges and electric dipole moments of elementary particles based upon the Cerenkov radiation which they would emit in dispersive media. (author)

  9. Interference of dissolved salts in Cerenkov and liquid scintillation estimation of 90Sr

    International Nuclear Information System (INIS)

    Pulhani, Vandana; Jha, S.K.; Tripathi, R.M.; Reddy, Priyanka; Bhade, Sonali

    2014-01-01

    Quenching is the most important effect occurring in Cerenkov and LSC because it affects the efficiency of conversion of β particles into light. Bore well water samples are very often concentrated by evaporation to reduce the detection limit which can also increase the dissolved solid content (TDS) in the sample. Some ground waters are inherently having higher TDS. Self-absorption of beta-particle radiation by the sample especially the lower-energy beta particles depends on sample thickness and density. Environmental samples, after applying the radiochemical procedure, are also estimated by Cerenkov/LSC and might be affected by colour quenching. To get best measurements using Liquid Scintillation and Cerenkov radiations, it is necessary to avoid high salt concentrations and colors which may weaken energy transfers within scintillator cocktails and sample medium. Therefore the degree of self-absorption and quench should be evaluated and taken into account in the calibration. Efficiency is represented as a function spectral quench parameter of external standard SQP(E). The quenching effect of dissolved solids on the efficiency of estimation of 90 Sr by Cerenkov and Liquid Scintillation are studied

  10. Weight Multispectral Reconstruction Strategy for Enhanced Reconstruction Accuracy and Stability With Cerenkov Luminescence Tomography.

    Science.gov (United States)

    Hongbo Guo; Xiaowei He; Muhan Liu; Zeyu Zhang; Zhenhua Hu; Jie Tian

    2017-06-01

    Cerenkov luminescence tomography (CLT) provides a novel technique for 3-D noninvasive detection of radiopharmaceuticals in living subjects. However, because of the severe scattering of Cerenkov light, the reconstruction accuracy and stability of CLT is still unsatisfied. In this paper, a modified weight multispectral CLT (wmCLT) reconstruction strategy was developed which split the Cerenkov radiation spectrum into several sub-spectral bands and weighted the sub-spectral results to obtain the final result. To better evaluate the property of the wmCLT reconstruction strategy in terms of accuracy, stability and practicability, several numerical simulation experiments and in vivo experiments were conducted and the results obtained were compared with the traditional multispectral CLT (mCLT) and hybrid-spectral CLT (hCLT) reconstruction strategies. The numerical simulation results indicated that wmCLT strategy significantly improved the accuracy of Cerenkov source localization and intensity quantitation and exhibited good stability in suppressing noise in numerical simulation experiments. And the comparison of the results achieved from different in vivo experiments further indicated significant improvement of the wmCLT strategy in terms of the shape recovery of the bladder and the spatial resolution of imaging xenograft tumors. Overall the strategy reported here will facilitate the development of nuclear and optical molecular tomography in theoretical study.

  11. Automatic scanning of Cerenkov light photograms from a multistep avalanche chamber using a television digitizer

    International Nuclear Information System (INIS)

    Vascon, M.; Zanella, G.

    1980-01-01

    A television digitizer and its application to automatic scanning of Cerenkov imaging using the multistep avalanche chamber in front of optical spark chamber are described. The results are of interest in the adoption of the automatic scanning of photographic plates of these events or for the on-line application of the television digitizer itself. (orig.)

  12. Charge and velocity resolution of Cerenkov counters in a beam of accelerated heavy nuclei

    International Nuclear Information System (INIS)

    Cantin, M.; Goret, P.; Jorrand, J.; Jouan, R.; Juliusson, E.; Koch, L.; Maubras, Y.; Mestreau, P.; Petrou, N.; Rio, Y.; Soutoul, A.; Cawood, P.; Linney, A.

    1975-01-01

    The response of various Cerenkov radiators to oxygen and nitrogen nuclei with energies ranging between 2.1GeV/n and 300MeV/n is presented. The velocity and charge resolutions are analyzed in relation to the possible use of these counters for chemical and isotopic analysis of the primary cosmic ray nuclei [fr

  13. A single-particle calculation of the FEL-Cerenkov gain

    International Nuclear Information System (INIS)

    Dattoli, G.; Doria, A.; Gallerano, G.P.; Renieri, A.; Schettini, G.; Torre, A.

    1988-01-01

    In this work it is shown that the basic FEL-Cerenkov dynamics can be modelled using a pendulumlike equation in close analogy with FEL undulator case. The analysis, including the inhomogeneous broadening effects, is worked out in the hypothesis of single-slab geometry. Two-dimensional motion dynamics effects are also included

  14. Detectors - Electronics

    International Nuclear Information System (INIS)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J.

    1998-01-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X → e - converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the 3 He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  15. Neutron-sensitive ZnS/10B2O3 ceramic scintillator detector as an alternative to a 3He-gas-based detector for a plutonium canister assay system

    International Nuclear Information System (INIS)

    Nakamura, T.; Ohzu, A.; Toh, K.; Sakasai, K.; Suzuki, H.; Honda, K.; Birumachi, A.; Ebine, M.; Yamagishi, H.; Takase, M.; Haruyama, M.; Kureta, M.; Soyama, K.; Nakamura, H.; Seya, M.

    2014-01-01

    A neutron-sensitive ZnS/ 10 B 2 O 3 ceramic scintillator detector was developed as an alternative to a 3 He-gas-based detector for use in a plutonium canister assay system. The detector has a modular structure, with a flat ZnS/ 10 B 2 O 3 ceramic scintillator strip that is installed diagonally inside a light-reflecting aluminium case with a square cross-section, and where the scintillation light is detected using two photomultiplier tubes attached at both ends of the case. The prototype detectors, which have a neutron-sensitive area of 30 mm×250 mm, exhibited a sensitivity of 21.7–23.4±0.1 cps/nv (mean±SD) for thermal neutrons, a 137 Cs gamma-ray sensitivity of 1.1–1.9±0.2×10 −7 and a count variation of less than 6% over the detector length. A trial experiment revealed a temperature coefficient of less than −0.24±0.05%/°C over the temperature range of 20–50 °C. The detector design and the experimental results are presented

  16. Design of the ATLAS New Small Wheel Gas Leak Tightness Station for the Micromegas Detector Modules

    CERN Document Server

    Gazis, Evangelos; The ATLAS collaboration

    2017-01-01

    In this work we describe advanced data processing and analysis techniques intended to be used in the gas tightness station at CERN for Quality Assurance and Quality Control of the New Small Wheel Micromegas Quadruplets. We combine two methods: a conventional one based on the Pressure Decay Rate and an alternative-novel one, based on the Flow Rate Loss. A prototype setup has been developed based on a Lock-in Amplifier device and should be operated in conjunction with the gas leak test via the Flow Rate Loss. Both methods have been tested by using emulated leak branches based on specific thin medical needles. The semi-automatic data acquisition, monitoring and processing system is presented also in this work while a more sophisticated environment based on the WinCC-OA SCADA is under development.

  17. Development of a technique for the efficiency calibration of a HPGe detector for the off gas samples of a nuclear reactor

    International Nuclear Information System (INIS)

    Singh, Sarbjit; Agarwal, Chhavi; Ramaswami, A.; Manchanda, V.K.

    2007-01-01

    Regular monitoring of off gases released to the environment from a nuclear reactor is mandatory. The gaseous fission products are estimated by gamma ray spectrometry using a HPGe detector coupled to a multichannel analyser. In view of the lack of availability of gaseous fission products standards, an indirect method based on the charcoal absorption technique was developed for the efficiency calibration of HPGe detector system using 133B a and 152E u standards. The known activities of 133B a and 152E u are uniformly distributed in a vial having activated charcoal and counted on the HPGe detector system at liquid nitrogen temperature to determine the gamma ray efficiency for the vial having activated charcoal. The ratio of the gamma ray efficiencies of off gas present in the normal vial and the vial having activated charcoal at liquid nitrogen temperature are used to determine the gamma ray efficiency of off gas present in the normal vial. (author)

  18. Evaluation of a gas chromatograph with a novel surface acoustic wave detector (SAW GC) for screening of volatile organic compounds in Hanford waste tank samples

    International Nuclear Information System (INIS)

    Lockrem, L.L.

    1998-01-01

    A novel instrument, a gas chromatograph with a Surface Acoustic Wave Detector (SAW GC), was evaluated for the screening of organic compounds in Hanford tank headspace vapors. Calibration data were developed for the most common organic compounds, and the accuracy and precision were measured with a certified standard. The instrument was tested with headspace samples collected from seven Hanford waste tanks

  19. Pulsed X-ray radiography of a gas jet target for laser-matter interaction experiments with the use of a CCD detector

    International Nuclear Information System (INIS)

    Rakowski, R.; Bartnik, A.; Fiedorowicz, H.; Jarocki, R.; Kostecki, J.; MikoIajczyk, J.; Szczurek, A.; Szczurek, M.; Foeldes, I.B.; Toth, Zs.

    2005-01-01

    Characterization of gas jet targets has been carried out using pulsed X-ray radiography. A laser-plasma X-ray source was applied for backlighting of the targets to obtain X-ray shadowgraphs registered with a CCD detector. From the shadowgraphs, characteristics of the targets were determined

  20. Calibration of a liquid scintillation counter for alpha, beta and Cerenkov counting

    International Nuclear Information System (INIS)

    Scarpitta, S.C.; Fisenne, I.M.

    1996-07-01

    Calibration data are presented for 25 radionuclides that were individually measured in a Packard Tri-Carb 2250CA liquid scintillation (LS) counter by both conventional and Cerenkov detection techniques. The relationships and regression data between the quench indicating parameters and the LS counting efficiencies were determined using microliter amounts of tracer added to low 40 K borosilicate glass vials containing 15 mL of Insta-Gel XF scintillation cocktail. Using 40 K, the detection efficiencies were linear over a three order of magnitude range (10 - 10,000 mBq) in beta activity for both LS and Cerenkov counting. The Cerenkov counting efficiency (CCE) increased linearly (42% per MeV) from 0.30 to 2.0 MeV, whereas the LS efficiency was >90% for betas with energy in excess of 0.30 MeV. The CCE was 20 - 50% less than the LS counting efficiency for beta particles with maximum energies in excess of 1 MeV. Based on replicate background measurements, the lower limit of detection (LLD) for a 1-h count at the 95% confidence level, using water as a solvent, was 0.024 counts sec- -1 and 0.028 counts sec-1 for plastic and glass vials, respectively. The LLD for a 1-h-count ranged from 46 to 56 mBq (2.8 - 3.4 dpm) for both Cerenkov and conventional LS counting. This assumes: (1) a 100% counting efficiency, (2) a 50% yield of the nuclide of interest, (3) a 1-h measurement time using low background plastic vials, and (4) a 0-50 keV region of interest. The LLD is reduced an order of magnitude when the yield recovery exceeds 90% and a lower background region is used (i.e., 100 - 500 keV alpha region of interest). Examples and applications of both Cerenkov and LS counting techniques are given in the text and appendices

  1. Endoscopic Cerenkov luminescence imaging: in vivo small animal tumor model validation

    Science.gov (United States)

    Song, Tianming; Bao, Chengpeng; Hu, Zhenhua; Wang, Kun; Liu, Xia; Tian, Jie

    2015-03-01

    Background: Cerenkov luminescence imaging (CLI) provides a great potential for clinical translation of optical molecular imaging techniques through using clinical approved radiotracers. However, it is difficult to obtain the Cerenkov luminescence signal of deeper biological tissues due to the small magnitude of the signal. To efficiently acquire the weak Cerenkov luminescence, we developed an endoscopic Cerenkov luminescence imaging (ECLI) system to reduce the in vivo imaging depth with minimum invasion, and validated the system on small animal tumor models. Methods: For the ECLI system, the laparoscope was connected to a high sensitive charge-couple device (CCD) camera (DU888+, Andor, UK) by a custom made adapter. We conducted a series of in vitro and in vivo experiments by use of the system. In the in vitro experiment, the endoscopic luminescence images of the 18F-FDG with various activities in EP tubes were acquired using ECLI system, and the sensitivity was compared with conventional CLI system. In the in vivo tumor experiment, 18F-FDG with the activity of 200μCi were intravenously injected into 3 tumor mice. Then the ECLI system was used to acquire the optical images for both non-invasive and invasive conditions. Conclusion: Experimental data showed the ECLI system could detect the 18F-FDG with the activity as low as 1μCi. Furthermore, our preliminary results indicated the possibility of ECLI technique for detecting Cerenkov signals inside the tumor tissue with deeper depth and guiding the surgical operation of tumor excision. We believe that this technique can help to accelerate the clinical translation of CLI.

  2. Lifetime Extension of the Gas Discharge Detectors with Plasma Etching of Silicon Deposits in 80%CF4 + 20%CO2

    Science.gov (United States)

    Gavrilov, G. E.; Vakhtel, V. M.; Maysuzenko, D. A.; Tavtorkina, T. A.; Fetisov, A. A.; Shvetsova, N. Yu.

    2017-12-01

    A method of elimination of silicon compounds from the anode wire of an aged proportional counter is presented. The aging of a counter with a 70%Ar + 30%CO2 and a 60%Ar + 30%CO2 + 10%CF4 working mixture was stimulated by a 90Sr β source. To accelerate the process of aging, the gas mixture flow to the counter was supplied through a pipe with RTV coated wall. As a result, the amplitude of the signal decreased 70% already at accumulated charge of Q = 0.03 C/cm. The etching of the silicon compounds on the wire surface with an 80%CF4 + 20%CO2 gas mixture discharge led to full recovery of the operating characteristics of detector and an increase in the lifetime. A scanning electron microscopy and X-ray spectroscopy analysis of the recovered wire surface were performed. In accordance with the results, a good quality of wire cleaning from SiO2 compounds was obtained.

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

    Science.gov (United States)

    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.

  4. Performance of wire-type Rn detectors operated with gas gain in ambient air in view of its possible application to early earthquake predictions

    CERN Document Server

    Charpak, Georges; Breuil, P; Nappi, E; Martinengo, P; Peskov, V

    2010-01-01

    We describe a detector of alpha particles based on wire type counters (single-wire and multiwire) operating in ambient air at high gas gains (100-1000). The main advantages of these detectors are: low cost, robustness and ability to operate in humid air. The minimum detectable activity achieved with the multiwire detector for an integration time of 1 min is 140 Bq per m3, which is comparable to that featured by commercial devices. Owing to such features the detector is suited for massive application, for example for continuous monitoring of Rn or Po contaminations or, as discussed in the paper, its use in a network of Rn counters in areas affected by earth-quakes in order to verify, on a solid statistical basis, the envisaged correlation between the sudden Rn appearance and a forthcoming earthquake.

  5. Solid state detectors for neutron radiation monitoring in fusion facilities

    International Nuclear Information System (INIS)

    Gómez-Ros, J.M.

    2014-01-01

    The purpose of this communication is to summarize the main solid state based detectors proposed for neutron diagnostic in fusion applications and their applicability under the required harsh conditions in terms of intense radiation, high temperature and available space restrictions. Activation systems, semiconductor based detectors, luminescent materials and Cerenkov fibre optics sensors (C-FOS) are the main devices that are described. - Highlights: • A state-of-the-art summary of solid state based detectors are described. • Conditions and restrictions for their applicability are described. • A list of the 38 more relevant references has been included

  6. Terahertz Radiation Heterodyne Detector Using Two-Dimensional Electron Gas in a GaN Heterostructure

    Science.gov (United States)

    Karasik, Boris S.; Gill, John J.; Mehdi, Imran; Crawford, Timothy J.; Sergeev, Andrei V.; Mitin, Vladimir V.

    2012-01-01

    High-resolution submillimeter/terahertz spectroscopy is important for studying atmospheric and interstellar molecular gaseous species. It typically uses heterodyne receivers where an unknown (weak) signal is mixed with a strong signal from the local oscillator (LO) operating at a slightly different frequency. The non-linear mixer devices for this frequency range are unique and are not off-the-shelf commercial products. Three types of THz mixers are commonly used: Schottky diode, superconducting hot-electron bolometer (HEB), and superconductor-insulation-superconductor (SIS) junction. A HEB mixer based on the two-dimensional electron gas (2DEG) formed at the interface of two slightly dissimilar semiconductors was developed. This mixer can operate at temperatures between 100 and 300 K, and thus can be used with just passive radiative cooling available even on small spacecraft.

  7. A new focal plane detector for the gas-filled separator TASCA

    International Nuclear Information System (INIS)

    Gorshkov, Alexander

    2010-01-01

    Superheavy elements (SHE) exist solely because of enhanced nuclear stability due to shell effects. The production cross sections for the synthesis of SHE decrease continuously, thus, exploration of SHE nuclei is close to the border of present technical limitation. To increase the efficiency and sensitivity in SHE experiments, highly efficient recoil separators with state-of-the-art detection systems are required. In the framework of this thesis, the new focal plane detection system with the dedicated electronics have been developed for the gas-filled recoil separator TASCA at the GSI Helmholtzzentrum for Schwerionenforschung GmbH. The new detection system has been successfully used in recent experiments on synthesis of the E114.

  8. Use of an external source (60Co) for 32P detection efficiency determination by the Cerenkov effect, in soil extracts

    International Nuclear Information System (INIS)

    Nascimento Filho, V.F. do.

    1975-03-01

    The detection of 32 P in aqueous extracts is usually made with the aid of a Geiger-Muller detector, with thin window and sample on a planchet. Presently the technique is being developed of detection of high energy beta particles emitters ( 32 P, 42 K, 86 Rb) through the Cerenkov effect, using a commercial liquid scintillation system. This technique, despite being approximately 30 times more sensitive, has the inconvenience of varying the detection efficiency, mainly for color samples (soil extracts, for instance). From this stems the need for determining the detection efficiency for each sample. The internal standardization and channels ratio methods show a series of drawbacks, mainly the non-reutilization of the samples (1st method) and statistical uncertainty for low activity samples (2nd method). The elimination of these dreawbacks can be achieved through the utilization of the external standardization method. A 60 Co source with 1,4 μCi activity has been adapted to the sample elevator of the detector system, and a comparison was made with the channels ratio method to evaluate the efficiency of 32 P detection in soil extracts (P extraction and fractionation). The external standardization method showed to be more accurate, besides being influenced to a lesser degree by high voltage variation, sample volume and vial types. In the case of large samples, it is advisable to carry out detection in vials filled up to their full capacity; in the case of small samples, the whole volume should be transferred to the vials and completed up to 9 ml for nylon vials,10 ml for glass vials and 11 to 14 ml for polyethilene vials. On the other hand, plastic vials showed higher detection efficiency than ones. As to background radiation, the lowest rates were given by nylon vials and the highest by Beckman glass vials [pt

  9. Computed tomography with thermal neutrons and gaseous position sensitive detector; Tomografia computadorizada com neutrons termicos e detetor a gas sensivel a posicao

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Maria Ines Silvani

    2001-12-01

    A third generation tomographic system using a parallel thermal neutron beam and gaseous position sensitive detector has been developed along three discrete phases. At the first one, X-ray tomographic images of several objects, using a position sensitive detector designed and constructed for this purpose have been obtained. The second phase involved the conversion of that detector for thermal neutron detection, by using materials capable to convert neutrons into detectable charged particles, testing afterwards its performance in a tomographic system by evaluation the quality of the image arising from several test-objects containing materials applicable in the engineering field. High enriched {sup 3} He, replacing the argon-methane otherwise used as filling gas for the X-ray detection, as well as, a gadolinium foil, have been utilized as converters. Besides the pure enriched {sup 3} He, its mixture with argon-methane and later on with propane, have been also tested, in order to evaluate the detector efficiency and resolution. After each gas change, the overall performance of the tomographic system using the modified detector, has been analyzed through measurements of the related parameters. This was done by analyzing the images produced by test-objects containing several materials having well known attenuation coefficients for both thermal neutrons and X-rays. In order to compare the performance of the position sensitive detector as modified to detect thermal neutrons, with that of a conventional BF{sub 3} detector, additional tomographs have been conducted using the last one. The results have been compared in terms of advantages, handicaps and complementary aspects for different kinds of radiation and materials. (author)

  10. Measurement of Cerenkov Radiation Induced by the Gamma-Rays of Co-60 Therapy Units Using Wavelength Shifting Fiber

    Directory of Open Access Journals (Sweden)

    Kyoung Won Jang

    2014-04-01

    Full Text Available In this study, a wavelength shifting fiber that shifts ultra-violet and blue light to green light was employed as a sensor probe of a fiber-optic Cerenkov radiation sensor. In order to characterize Cerenkov radiation generated in the developed wavelength shifting fiber and a plastic optical fiber, spectra and intensities of Cerenkov radiation were measured with a spectrometer. The spectral peaks of light outputs from the wavelength shifting fiber and the plastic optical fiber were measured at wavelengths of 500 and 510 nm, respectively, and the intensity of transmitted light output of the wavelength shifting fiber was 22.2 times higher than that of the plastic optical fiber. Also, electron fluxes and total energy depositions of gamma-ray beams generated from a Co-60 therapy unit were calculated according to water depths using the Monte Carlo N-particle transport code. The relationship between the fluxes of electrons over the Cerenkov threshold energy and the energy depositions of gamma-ray beams from the Co-60 unit is a near-identity function. Finally, percentage depth doses for the gamma-ray beams were obtained using the fiber-optic Cerenkov radiation sensor, and the results were compared with those obtained by an ionization chamber. The average dose difference between the results of the fiber-optic Cerenkov radiation sensor and those of the ionization chamber was about 2.09%.

  11. Residual solvent determination by head space gas chromatography with flame ionization detector in omeprazole API

    Directory of Open Access Journals (Sweden)

    Saurabh Pandey

    2011-06-01

    Full Text Available Residual solvents in pharmaceutical samples are monitored using gas chromatography with head space. Based on good manufacturing practices, measuring residual solvents is mandatory for the release testing of all active pharmaceutical ingredients (API. The analysis of residual organic solvents (methanol, acetone, cyclohexane, dichloromethane, toluene in Omeprazole, an active pharmaceutical ingredient was investigated. Omeprazole is a potent reversible inhibitor of the gastric proton pump H+/K+-ATPase. The Head space gas chromatography (HSGC method described in this investigation utilized a SPB TM-624, Supelco, 30 m long x 0.25 mm internal diameter, 1.4µm-thick column. Since Omeprazole is a thermally labile compound, the selection of the proper injector temperature is critical to the success of the analysis. The injector temperature was set at 170ºC to prevent degradation. The initial oven temperature was set at 40ºC for 12 min and programmed at a rate of 10ºC min-1 to a final temperature of 220ºC for 5 min. Nitrogen was used as a carrier gas. The sample solvent selected was N,N-dimethylacetamide. The method was validated to be specific, linear, precise, sensitive, rugged and showed excellent recovery.Solventes residuais em amostras farmacêuticas são monitoradas utilizando-se cromatografia a gás "headspace". Com base nas boas práticas de fabricação, a medida de solventes residuais é obrigatória para o teste de liberação de todos os ingredientes farmacêuticos (API. Efetuou-se a análise de solventes orgânicos residuais (metanol, acetona, cicloexano, diclorometano, tolueno em omeprazol, ingrediente farmacêutico ativo. O omeprazol é potente inibidor reversível da bomba de prótons H+/K+-ATPase. A cromatografia a gás "headspace" (HSGC descrita nessa pesquisa utilizou um SPB TM-624, Supelco, de 30 m de comprimento x 0,25 mm de diâmetro interno, e coluna de 1,4 µm de espessura. Considerando-se que o omeprazol é termicamente l

  12. Spent Nuclear Fuel Cask and Storage Monitoring with {sup 4}He Scintillation Fast Neutron Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hee jun; Kelley, Ryan P; Jordan, Kelly A [Univ. of Florida, Florida (United States); Lee, Wanno [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Chung, Yong Hyun [Yonsei Univ., Wonju (Korea, Republic of)

    2014-10-15

    With this increasing quantity of spent nuclear fuel being stored at nuclear plants across S. Korea, the demand exists for building a long-term disposal facility. However, the Korean government first requires a detailed plan for the monitoring and certification of spent fuel. Several techniques have been developed and applied for the purpose of spent fuel monitoring, including the digital Cerenkov viewing device (DCVD), spent fuel attribute tester (SFAT), and FORK detector. Conventional gamma measurement methods, however, suffer from a lack of nuclear data and interfering background radiation. To date, the primary method of neutron detection for spent fuel monitoring has been through the use of thermal neutron detectors such as {sup 3}He and BF{sub 3} proportional counters. Unfolding the neutron spectrum becomes extremely complicated. In an attempt to overcome these difficulties, a new fast neutron measurement system is currently being developed at the University of Florida. This system is based on the {sup 4}He scintillation detector invented by Arktis Radiation Detectors Ltd. These detectors are a relatively new technological development and take advantage of the high {sup 4}He cross-section for elastic scattering at fast neutron energies, particularly the resonance around 1 MeV. This novel {sup 4}He scintillation neutron detector is characterized by its low electron density, leading to excellent gamma rejection. This detector also has a fast response time on the order of nanoseconds and most importantly, preserves some neutron energy information since no moderator is required. Additionally, these detectors rely on naturally abundant {sup 4}He as the fill gas. This study proposes a new technique using the neutron spectroscopy features of {sup 4}He scintillation detectors to maintain accountability of spent fuel in storage. This research will support spent fuel safeguards and the detection of fissile material, in order to minimize the risk of nuclear proliferation

  13. A study of an optimal technological solution for the electronics of particle position sensitive gas detectors (multiwire proportional chambers)

    International Nuclear Information System (INIS)

    Zojceski, Z.

    1997-01-01

    This work aims at optimizing the electronics for position sensitive gas detectors. The first part is a review of proportional chamber operation principles and presents the different possibilities for the architecture of the electronics. The second part involves electronic signal processing for best signal-to-noise ratio. We present a time-variant filter based on a second order base line restorer.It allows a simple pole-zero and tail cancellation at high counting rates. Also, various interpolating algorithms for cathode strip chambers have been studied. The last part reports the development of a complete electronic system, from the preamplifiers up to the readout and control interface, for the cathode strip chambers in the focal plane of the BBS Spectrometer at KVI, Holland. The system is based on application specific D-size VXI modules. In all modules, the 16-bit ADCs and FIFO memory are followed by a Digital Signal Processor, which performs data filtering and cathode induced charge interpolation. Very good analog noise performance is obtained in a multi-processor environment. (author)

  14. Prediction of gas chromatography/electron capture detector retention times of chlorinated pesticides, herbicides, and organohalides by multivariate chemometrics methods

    International Nuclear Information System (INIS)

    Ghasemi, Jahanbakhsh; Asadpour, Saeid; Abdolmaleki, Azizeh

    2007-01-01

    A quantitative structure-retention relationship (QSRR) study, has been carried out on the gas chromatograph/electron capture detector (GC/ECD) system retention times (t R s) of 38 diverse chlorinated pesticides, herbicides, and organohalides by using molecular structural descriptors. Modeling of retention times of these compounds as a function of the theoretically derived descriptors was established by multiple linear regression (MLR) and partial least squares (PLS) regression. The stepwise regression using SPSS was used for the selection of the variables that resulted in the best-fitted models. Appropriate models with low standard errors and high correlation coefficients were obtained. Three types of molecular descriptors including electronic, steric and thermodynamic were used to develop a quantitative relationship between the retention times and structural properties. MLR and PLS analysis has been carried out to derive the best QSRR models. After variables selection, MLR and PLS methods used with leave-one-out cross validation for building the regression models. The predictive quality of the QSRR models were tested for an external prediction set of 12 compounds randomly chosen from 38 compounds. The PLS regression method was used to model the structure-retention relationships, more accurately. However, the results surprisingly showed more or less the same quality for MLR and PLS modeling according to squared regression coefficients R 2 which were 0.951 and 0.948 for MLR and PLS, respectively

  15. Testing CuO nanowires as a novel X-ray to electron converter for gas-filled radiation detectors

    Science.gov (United States)

    Zarei, H.; Saramad, S.; Razaghi, S.

    2017-10-01

    Nanowires, due to their special physical properties and also high surface to volume ratio, can have considerable applications in designing and development of novel nanodevices. For the radiation shielding, higher absorption coefficient of nanostructures in comparison to bulk ones is an advantage. In gas detectors, designing a proper converter that absorbs higher energy of gamma and X-rays and convert it to more free electrons is one of the major problems. Since the nanowires have higher surface to volume ratio in comparison to the bulk one, so it is expected that by optimizing the thickness, the generated electrons can have higher chance to escape from the surface. In this work, the random CuO nanowires with diameter of 40 nm are deposited on thin glass slide. This nanostructure with different thicknesses are tested by plastic and CsI scintillators by X-ray tube with HVs in the range of 16 to 25 kV. The results show that for the same thickness, the CuO nanowires can release electrons six times more than the bulk ones and for the same energy the optimum QE of nanoconverter can be three times greater than the bulk converter. This novel nanoconverter with higher detection efficiency can have applications in high energy physics, medical imaging and also astronomy.

  16. Proposed Hall D Detector Electronics

    International Nuclear Information System (INIS)

    Paul Smith

    1998-01-01

    With nearly 10**5 channels, the signal processing and data acquisition electronics system will present a significant challenge. We envisage much of the electronics being physically located on or near the detectors to avoid the long and expensive low-level signal cables otherwise required. CERN detectors such as COMPASS and ATLAS provide a good model, and we should build on their experience as much as possible. Radiation hardness and minimal power dissipation are additional constraints. The high beam rate will necessitate good time resolution, integrated low level triggering capability and sufficient pipelining of the data to accommodate the trigger decision time. A proposed architecture is shown in the figure. Detector channels are either ''pixels'', e.g. PWCs, drift chambers, and ring cerenkovs, or charge detectors, e.g. CSI or lead glass. Pixel detectors are discriminated, while charge detectors are digitized by Flash ADCs (FADC). The digitized information is pipelined in shift registers which provide a time window for the first level of triggering to consider. After passing through the shift registers, the data are further pipelined in RAM to provide time for the level 1 trigger decision. In the event of a level 1 trigger, the RAM contents are transferred to a level 2 processor farm where more detailed trigger decisions take place

  17. Possible influence of cosmic ray Cerenkov photons on infrared interferometric search for non-solar planets

    International Nuclear Information System (INIS)

    Lerche, I.

    1980-01-01

    It is shown that the pervasive cosmic-ray protons in the vicinity of the Earth would produce infrared photons by Cerenkov radiation in the material walls, and mirrors, of an orbiting infrared interferometer designed to search for non-solar planets. The flux of such photons is at least comparable to the zodiacal infrared background radiation. It is found that for the worst possible conditions a minimum time of about six weeks is indicated for planetary detection using a fourth-harmonic noise analysis. It is suggested that direct laboratory measurement of a simulated cosmic-ray-induced Cerenkov flux be undertaken to settle the question of the background contaminant produced by this effect. (Auth.)

  18. Cerenkov light generated in optical fibres and other light pipes irradiated by electron beams

    International Nuclear Information System (INIS)

    Beddar, A.S.; Mackie, T.R.; Attix, F.H.

    1992-01-01

    The use of a small plastic scintillator coupled to an optical fibre bundle light pipe for the dosimetry of radiotherapy x-ray or electron beams in a phantom has been studied. Under such conditions, some light is generated by the direct action of the radiation on the optical fibres themselves, and this 'background' signal must be correctly accounted for. Electron beams were incident on fused silica optical fibres and other light pipes made of polymethylmethacrylate (PMMA), polystyrene and water. The observed light signal generated in all cases was found to depend strongly on the angle between the electron direction and the light pipe axis, and to correlate well with the angular characteristics uniquely associated with Cerenkov radiation. The use of a parallel fibre bundle light pipe, identical to the one that carries light from the scintillator, offers a suitable means of generating a similar background Cerenkov light signal that can be subtracted to obtain output from the scintillation dosimeter alone. (author)

  19. Cerenkov Counter for In-Situ Groundwater Monitoring of 90Sr

    Directory of Open Access Journals (Sweden)

    Lindsay C. Todd

    2005-02-01

    Full Text Available Groundwater contamination from 90Sr is an environmental challenge posed topresent and former nuclear weapons related sites. Traditional methods of extractinggroundwater samples and performing laboratory analyses are expensive, time-consumingand induce significant disposal challenges. The authors present here a prototype countercapable of measuring 90Sr groundwater concentrations in-situ at or below the drinking waterlimit of 8 pCi/liter. The 90Y daughter of 90Sr produces high-energy electrons, which cancreate Cerenkov light. Photomultiplier tubes convert the Cerenkov light into an electronicpulse, which then undergoes signal processing with standard electronics. Strontium-90concentrations near the drinking water limit can be measured in a matter of hours if it is insecular equilibrium with the 90Y daughter. The prototype counter is compact, can bedeployed in an American Standard 6-inch, well while operated by a single person, andtransmits the results to a central monitoring location.

  20. Why Cerenkov Radiation May Not Occur, Even When It Is Allowed by Lorentz-Violating Kinematics

    Directory of Open Access Journals (Sweden)

    Brett Altschul

    2017-10-01

    Full Text Available In a Lorentz-violating quantum field theory, the energy-momentum relations for the field quanta are typically modified. This affects the kinematics, and processes that are normally forbidden may become allowed. One reaction that clearly becomes kinematically possible when photons’ phase speeds are less than 1 is vacuum Cerenkov radiation. However, in spite of expectations, and in defiance of phase space estimates, a electromagnetic Chern–Simons theory with a timelike Lorentz violation coefficient does not feature any energy losses through Cerenkov emission. There is an unexpected cancelation, made possible by the existence of unstable long-wavelength modes of the field. The fact that the theory possesses a more limited form of gauge symmetry than conventional electrodynamics also plays a role.

  1. Separation of PbWO4 and BGO signals into Cerenkov and scintillation components

    International Nuclear Information System (INIS)

    Voena, C

    2009-01-01

    We present results from beam tests performed in 2007 on PbWO 4 and BGO crystals in the context of the DREAM project. Signals from high energy electrons and pions are analyzed and the possibility of separating the contributions from Cerenkov (C) and scintillation (S) light for individual events is investigated. Different methods exploiting the difference in timing, in the spectra and in the directionality of the two types of light have been developed to determine the contribution of the two components. In the BGO crystal, Cerenkov signals have been enhanced with the use of optical filters and the ratio C/S is measured with good precision (∼20-30% for energy deposits less than 1 GeV).

  2. Study of a microstrip gas detector for the Compact Muon Solenoid experiment; Etude d`un detecteur a micropistes pour l`experience Compact Muon Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Clergeau, J F [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire

    1997-06-19

    The micro-strip gas chambers (MSGC) were realized due to the technological advances in the field of micro-electronics. The wire of usual gas counters is replaced in these detectors by metallic stripes as a periodic sequence of electrodes (anodes and cathodes) spaced by around 200 {mu}m. At a distance of 3 mm above the strip containing substrate, a metallic plane is placed, thus defining the gaseous room where the passage of a charged particle produces by ionization a primary electron signal collected by the detector anodes. Due to its granularity a MSGC can operate under very high particle fluxes since charge can be collected very rapidly. Also, the impact parameters can be determined with high accuracy due to the high space and time resolutions. The Compact Muon Solenoid (CMS) or the MSGC detectors planned to equip one of the experiments proposed for LHC should detect, in extreme operational conditions, the particle impacts in a 4 Tesla magnetic field, for around ten years and for a particle flux of around 10{sup 4} Hz/mm{sup 2}. The CMS detector is described in chapter 2. The operation principle and the problems encountered in the development of MSGC detectors are summarized in chapter 3. The chapter 4 is dedicated to the study of the performances of MSGCs in magnetic fields. In the chapters 5 to 7 the processing of the signal from detectors of this type is described, particularly, the performances of various ways of treat the signal in terms of detection efficiency and counting loads are presented.The chapter 8 presents the results obtained with the prototype obtained at IPNL while the chapter 9 gives the conclusions of the performed works. (author) 55 refs.

  3. Low-Cost, Fiber-Optic Hydrogen Gas Detector Using Guided-Wave, Surface-Plasmon Resonance in Chemochromic Thin Films

    International Nuclear Information System (INIS)

    Tracy, C.E.; Benson, D.K.; Haberman, D.P.; Hishmeh, G.A.; Ciszek, P.A.

    1998-01-01

    Low-cost, hydrogen-gas-leak detectors are needed for many hydrogen applications, such as hydrogen-fueled vehicles where several detectors may be required in different locations on each vehicle. A fiber-optic leak detector could be inherently safer than conventional detectors, because it would remove all detector electronics from the vicinity of potential leaks. It would also provide freedom from electromagnetic interference, a serious problem in fuel-cell-powered electric vehicles. This paper describes the design of a fiber-optic, surface-plasmon-resonance hydrogen detector, and efforts to make it more sensitive, selective, and durable. Chemochromic materials, such as tungsten oxide and certain Lanthanide hydrides, can reversibly react with hydrogen in air while exhibiting significant changes in their optical properties. Thin films of these materials applied to a sensor at the end of an optical fiber have been used to detect low concentrations of hydrogen gas in air. The coatings include a thin silver layer in which the surface plasmon is generated, a thin film of the chemochromic material, and a catalytic layer of palladium that facilitates the reaction with hydrogen. The film thickness is chosen to produce a guided-surface plasmon wave along the interface between the silver and the chemochromic material. A dichroic beam-splitter separates the reflected spectrum into a portion near the resonance and a portion away from the resonance, and directs these two portions to two separate photodiodes. The electronic ratio of these two signals cancels most of the fiber transmission noise and provides a stable hydrogen signal

  4. Cerenkov light and the production of photoreactivatable damage in X-irradiated E. coli

    International Nuclear Information System (INIS)

    Redpath, J.L.; Zabilansky, E.; Morgan, T.; Ward, J.F.

    1981-01-01

    Survival curve data for oxygenated E. coli AB2480 irradiated with 6 MVp photons in the absence and presence of DNA are presented for bacteria which have or have not received photoreactivation treatment following x-ray exposure. At the concentration of DNA used (OD = 4.4 at 260 nm) partial protection against induction of photoreactivatable damage was attained. Following photoreactivation the survival curves had the same slope, irrespective of the presence or absence of DNA. Survival data for oxygenated E.coli AB2480 irradiated with 50 Gy of 6 MVp photons in the presence of DNA at varying concentrations (OD range 0.5 to 12) and then processed with or without exposure to photoreactivating light are also presented. Survival increased with DNA concentration in the absence, but not in the presence, of photoreactivation. It is concluded that theoretical considerations and experimental data are consistent with Cerenkov light being responsible for the production of a major part of the photoreactivatable damage induced in E.coli DNA by high energy X-,γ- or electron irradiation, but that the data obtained with low energy X-rays (300 kVp) and with high energy X-rays (6 MVp) plus DNA as a 'scavenger' of Cerenkov light, are indicative of a component of the photoreactivatable damage being induced by a mechanism not involving Cerenkov light. (U.K.)

  5. Cerenkov light and the production of photoreactivatable damage in X-irradiated E. coli

    Energy Technology Data Exchange (ETDEWEB)

    Redpath, J L; Zabilansky, E; Morgan, T [California Univ., Irvine (USA). Dept. of Radiological Sciences; Ward, J F [California Univ., San Diego, La Jolla (USA). Dept. of Radiology

    1981-05-01

    Survival curve data for oxygenated E. coli AB2480 irradiated with 6 MVp photons in the absence and presence of DNA are presented for bacteria which have or have not received photoreactivation treatment following x-ray exposure. At the concentration of DNA used (OD = 4.4 at 260 nm) partial protection against induction of photoreactivatable damage was attained. Following photoreactivation the survival curves had the same slope, irrespective of the presence or absence of DNA. Survival data for oxygenated E.coli AB2480 irradiated with 50 Gy of 6 MVp photons in the presence of DNA at varying concentrations (OD range 0.5 to 12) and then processed with or without exposure to photoreactivating light are also presented. Survival increased with DNA concentration in the absence, but not in the presence, of photoreactivation. It is concluded that theoretical considerations and experimental data are consistent with Cerenkov light being responsible for the production of a major part of the photoreactivatable damage induced in E. coli DNA by high energy X-, ..gamma..- or electron irradiation, but that the data obtained with low energy X-rays (300 kVp) and with high energy X-rays (6 MVp) plus DNA as a scavenger of Cerenkov light, are indicative of a component of the photoreactivatable damage being induced by a mechanism not involving Cerenkov light.

  6. Evaluation of a portable gas chromatograph with photoionization detector under variations of VOC concentration, temperature, and relative humidity.

    Science.gov (United States)

    Soo, Jhy-Charm; Lee, Eun Gyung; LeBouf, Ryan F; Kashon, Michael L; Chisholm, William; Harper, Martin

    2018-04-01

    The objective of this present study was to evaluate the performance of a portable gas chromatograph-photoionization detector (GC-PID), under various test conditions to determine if it could be used in occupational settings. A mixture of 7 volatile organic compounds (VOCs)-acetone, ethylbenzene, methyl isobutyl ketone, toluene, m-xylene, p-xylene, and o-xylene-was selected because its components are commonly present in paint manufacturing industries. A full-factorial combination of 4 concentration levels (exposure scenarios) of VOC mixtures, 3 different temperatures (25°C, 30°C, and 35°C), and 3 relative humidities (RHs; 25%, 50%, and 75%) was conducted in a full-size controlled environmental chamber. Three repetitions were conducted for each test condition allowing for estimation of accuracy. Time-weighted average exposure data were collected using solid sorbent tubes (Anasorb 747, SKC Inc.) as the reference sampling medium. Calibration curves of Frog-4000 using the dry gases showed R 2 > 0.99 for all analytes except for toluene (R 2 = 0.97). Frog-4000 estimates within a test condition showed good consistency for the performance of repeated measurement. However, there was ∼41-64% reduction in the analysis of polar acetone with 75% RH relative to collection at 25% RH. Although Frog-4000 results correlated well with solid sorbent tubes (r = 0.808-0.993, except for toluene) most of the combinations regardless of analyte did not meet the <25% accuracy criterion recommended by NIOSH. The effect of chromatographic co-elution can be seen with m, p-xylene when the results are compared to the sorbent tube sampling technique with GC-flame ionization detector. The results indicated an effect of humidity on the quantification of the polar compounds that might be attributed to the pre-concentrator placed in the selected GC-PID. Further investigation may resolve the humidity effect on sorbent trap with micro GC pre-concentrator when water vapor is present. Although this

  7. Determination of hydrogen in zirconium and its alloys by melt extraction under carrier gas flow using thermal conductivity cell as detector

    International Nuclear Information System (INIS)

    Akhtar, J.; Ahmed, M.; Mohammad, B.; Jan, S.; Waqar, F.

    1987-06-01

    In the production of zirconium metal and its alloys the presence of hydrogen impurity affects mechanical and corrosion resistance properties of the product. Therefore, determination of hydrogen contents of the product is necessary. Conditions for its analysis by melt extraction under carrier gas stream using thermal conductivity cell as detector were studied and optimised. The method is capable of measuring hydrogen impurity in parts per million range. (author)

  8. Realization of the low background neutrino detector Double Chooz. From the development of a high-purity liquid and gas handling concept to first neutrino data

    Energy Technology Data Exchange (ETDEWEB)

    Pfahler, Patrick

    2012-12-17

    produced and, together with all other ingredients of muon veto and buffer, delivered to the experiment, where they were mixed and tuned in due consideration of the individual requirements of the different liquids. For the filling and handling of the DC-far detector, the underground laboratory was equipped with a comprehensive liquid-handling, gas-handling and monitoring-system, which provides all necessary functions to flush, fill, operate and empty the detector safely. Using these systems, the DC-far detector was flushed and filled in accordance with an especially developed sequence, which considered critical filling points and avoided unnecessary stress on the different detector vessels. By the means of this, the far detector of Double Chooz could be filled without damaging the detector vessels. In addition, it could be demonstrated that the quality and cleanliness of the detector liquids were maintained during filling. As a result of this, Double Chooz was able to acquire first neutrino data and to publish its first result of {Theta}{sub 13} with sin{sup 2}(2{Theta}{sub 13})=0.109 {+-} 0.030(stat.) {+-} 0.025(syst.).

  9. Realization of the low background neutrino detector Double Chooz. From the development of a high-purity liquid and gas handling concept to first neutrino data

    International Nuclear Information System (INIS)

    Pfahler, Patrick

    2012-01-01

    , together with all other ingredients of muon veto and buffer, delivered to the experiment, where they were mixed and tuned in due consideration of the individual requirements of the different liquids. For the filling and handling of the DC-far detector, the underground laboratory was equipped with a comprehensive liquid-handling, gas-handling and monitoring-system, which provides all necessary functions to flush, fill, operate and empty the detector safely. Using these systems, the DC-far detector was flushed and filled in accordance with an especially developed sequence, which considered critical filling points and avoided unnecessary stress on the different detector vessels. By the means of this, the far detector of Double Chooz could be filled without damaging the detector vessels. In addition, it could be demonstrated that the quality and cleanliness of the detector liquids were maintained during filling. As a result of this, Double Chooz was able to acquire first neutrino data and to publish its first result of Θ 13 with sin 2 (2Θ 13 )=0.109 ± 0.030(stat.) ± 0.025(syst.).

  10. Investigation of the behaviour of both dead time and observed counting rates of He-3 gas filled neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Eid, Y.; Abdel Kawy, A.; Maayouf, R.M.A.; Shuriet, G.M.; Hamouda, I.

    1981-01-01

    The behaviour of the dead time of He-3 detector, operating at both the proportional and the corona discharge regions, is investigated as a function of the neutron reaction rate inside the detector. The applied experimental method makes use of the fluctuations, due to the detector dead time in the observed counting rates from Poisson's distribution. In order to check the validity of the experimental method used in the present work, the dead time of BF/sub 3/ neutron detectors with different efficiencies (due to different enrichement in B-10) were determined. It is shown that the observed counting rate from the He-3 detector operating at the proportional region for neutron reaction rates ranging from 8 x 10/sup 3/ to 2.5 x 10/sup 4/ reaction/sec decreases with the increase of the neutron reaction rate. Such behaviour was not observed when operating the He-3 detector at the corona discharge region.

  11. Investigation of the behaviour of both dead time and observed counting rates of He-3 gas filled neutron detector

    International Nuclear Information System (INIS)

    Adib, M.; Eid, Y.; Abdel Kawy, A.; Maayouf, R.M.A.; Shuriet, G.M.; Hamouda, I.

    1981-01-01

    The behaviour of the dead time of He-3 detector, operating at both the proportional and the corona discharge regions, is investigated as a function of the neutron reaction rate inside the detector. The applied experimental method makes use of the fluctuations, due to the detector dead time in the observed counting rates from Poisson's distribution. In order to check the validity of the experimental method used in the present work, the dead time of BF 3 neutron detectors with different efficiencies (due to different enrichement in B-10) were determined. It is shown that the observed counting rate from the He-3 detector operating at the proportional region for neutron reaction rates ranging from 8 x 10 3 to 2.5 x 10 4 reaction/sec decreases with the increase of the neutron reaction rate. Such behaviour was not observed when operating the He-3 detector at the corona discharge region. (orig.) [de

  12. Towards time-of-flight PET with a semiconductor detector

    Science.gov (United States)

    Ariño-Estrada, Gerard; Mitchell, Gregory S.; Kwon, Sun Il; Du, Junwei; Kim, Hadong; Cirignano, Leonard J.; Shah, Kanai S.; Cherry, Simon R.

    2018-02-01

    The feasibility of using Cerenkov light, generated by energetic electrons following 511 keV photon interactions in the semiconductor TlBr, to obtain fast timing information for positron emission tomography (PET) was evaluated. Due to its high refractive index, TlBr is a relatively good Cerenkov radiator and with its wide bandgap, has good optical transparency across most of the visible spectrum. Coupling an SiPM photodetector to a slab of TlBr (TlBr-SiPM) yielded a coincidence timing resolution of 620 ps FWHM between the TlBr-SiPM detector and a LFS reference detector. This value improved to 430 ps FWHM by applying a high pulse amplitude cut based on the TlBr-SiPM and reference detector signal amplitudes. These results are the best ever achieved with a semiconductor PET detector and already approach the performance required for time-of-flight. As TlBr has higher stopping power and better energy resolution than the conventional scintillation detectors currently used in PET scanners, a hybrid TlBr-SiPM detector with fast timing capability becomes an interesting option for further development.

  13. Microstrip gas detectors development for the CMS tracker and branching fractions measurement of hadronic B decays with the BaBar experiment

    International Nuclear Information System (INIS)

    Zghiche, A.

    2007-01-01

    The Compact Muon Solenoid (CMS) is one of the two detectors, designed for the search of the Higgs boson at the Large Hadron Collider (LHC), to operate late 2007 at CERN. Micro Strip Gas Counters (MSGC) have been extensively studied to qualify as part of the CMS tracker. When exposed to highly ionizing particles and to high rates of incident particles, MSGCs have shown a good behavior allowing them to cope with the LHC environment. Similar micro pattern gaseous detectors such as Gas Electron Multiplier (GEM) and Micro Mesh gas detectors (MicroMegas) are developed to be used in high energy physics. BaBar, the detector for the Slac PEP-II asymmetric e + e - B Factory operating at the Y(4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. First observation of CP violation has been realized in 2001. Since then an impressive amount of B decays measurements has been performed. Among those, we present here the branching fraction measurements of charged and neutral B decays to Dπ - , D * π - , and D ** π - with a missing mass method, based on a sample of 231 million Y(4S) → BB-bar pairs. In order to do this, one of the B mesons is fully reconstructed and the 'recoil' one decays into a reconstructed charged pion and a companion charmed meson identified by its recoil mass, inferred by kinematics. The same sample is used to reconstruct charmed mesons (D, Ds) and baryons (Λ c ) in the 'recoil side' allowing the measurement of the charm number in the B decays. (author)

  14. Measurement of the Crab nebula (M1) gamma rays emission spectrum above 1 TeV using the Cerenkov light detection of atmospheric showers

    International Nuclear Information System (INIS)

    Djannati-Atai, Arache

    1995-01-01

    One of the major impediments towards reliable measurements in ground-based gamma ray astronomy comes from the lack of a tagged cosmic beam of gamma rays for calibrating the detectors. The main aim of this thesis - done within the framework of the Themistocle experiment - has been to provide a calibration method using the known flux of hadronic cosmic rays as a test beam. After a brief review of the most recent results in gamma ray astronomy and an introduction to the atmospheric Cerenkov technique, we describe the setup of the Themistocle experiment. We then present the calibration method, its performances and the procedures set up for the simulation of the hadronic air showers and the detector. The application of the calibration method to data from almost 400 hours of observation of the Crab nebula will then allow us to give one of the most accurate measurements of its spectrum between 3 and 13 TeV, measurement which is an important step towards the Crab becoming a standard cradle in this energy range. (author) [fr

  15. The study of CP violation in the B{sup 0} {yields} D{sup +}D{sup -} by means of the BABAR detector. Measurement of the performances of DIRC Cherenkov detector of BABAR: Prototype-II and final detector; L'etude de la violation de CP dans le canal B{sup 0} {yields} D{sup +}D{sup -} a l'aide du detecteur BABAR. La mesure des performances du detecteur Cerenkov DIRC de BABAR: Prototype -II et detecteur final

    Energy Technology Data Exchange (ETDEWEB)

    Benkebil, Mehdi [Lab. de l' Accelerateur Lineaire, Paris-11 Univ., 91 - Orsay (France)

    1999-04-16

    The work presented in this thesis is divided into two parts: the physics analysis of the decay mode B{sup 0} {yields} D{sup +}D{sup -} and the performance obtained with a new type of a particle identification detector using the Cherenkov effect technique: the DIRC. The analysis of this decay mode has been performed with data generated from fast simulation and a preliminary version of the reconstruction program. The branching ratio of this channel is predicted to be 4.5 x 10{sup -4}. The uncertainty in the sin 2 {beta} measurement obtained with this mode is: {sigma}(sin 2{beta})0.19 and 0.32 for fast simulation and preliminary version of the reconstruction program, respectively. The comparison of this result with the one obtained in the B{sup 0} {yields} J/{psi}K{sub s}{sup 0} mode will bring very useful theoretical insights. The performance study of the DIRC has been done on the prototype-II and the final detector. The beam-test results in terms resolution on the {theta}{sub c} angle and number of Cherenkov photons are the following: {sigma}({theta}{sub c}) = 10.2 {+-} 0.1 mrad per photon, {sigma}({theta}{sub c}) = 3.2 {+-} 0.2 mrad per track and N{sub {gamma}} 15.7 {+-} 0.1 at {theta}{sub dip} = 20 angle and 0 transmission in the bar. The analysis of the first cosmic data collected by the BABAR detector has allowed to study the DIRC in its final configuration. Among all the results obtained, we give the following ones: {sigma}({theta}{sub c}) = 10.09 {+-} 0.06 mrad per photon, {sigma}({theta}{sub c}) = 4.71 {+-} 0.14 mrad per track and N{sub {gamma}} 35.2 {+-} 3.8 at {theta}{sub dip} = 20 angle and 0 transmission in the bar. The extrapolation to the real condition of BABAR for all these results shows that the DIRC will run with performances similar to the nominal values. A detailed study of the background shows that, even though it will not be negligible, it will not compromise the DIRC performances in BABAR.

  16. The study of CP violation in the B{sup 0} {yields} D{sup +}D{sup -} by means of the BABAR detector. Measurement of the performances of DIRC Cherenkov detector of BABAR: Prototype-II and final detector; L'etude de la violation de CP dans le canal B{sup 0} {yields} D{sup +}D{sup -} a l'aide du detecteur BABAR. La mesure des performances du detecteur Cerenkov DIRC de BABAR: Prototype -II et detecteur final

    Energy Technology Data Exchange (ETDEWEB)

    Benkebil, Mehdi [Lab. de l' Accelerateur Lineaire, Paris-11 Univ., 91 - Orsay (France)

    1999-04-16

    The work presented in this thesis is divided into two parts: the physics analysis of the decay mode B{sup 0} {yields} D{sup +}D{sup -} and the performance obtained with a new type of a particle identification detector using the Cherenkov effect technique: the DIRC. The analysis of this decay mode has been performed with data generated from fast simulation and a preliminary version of the reconstruction program. The branching ratio of this channel is predicted to be 4.5 x 10{sup -4}. The uncertainty in the sin 2 {beta} measurement obtained with this mode is: {sigma}(sin 2{beta})0.19 and 0.32 for fast simulation and preliminary version of the reconstruction program, respectively. The comparison of this result with the one obtained in the B{sup 0} {yields} J/{psi}K{sub s}{sup 0} mode will bring very useful theoretical insights. The performance study of the DIRC has been done on the prototype-II and the final detector. The beam-test results in terms resolution on the {theta}{sub c} angle and number of Cherenkov photons are the following: {sigma}({theta}{sub c}) = 10.2 {+-} 0.1 mrad per photon, {sigma}({theta}{sub c}) = 3.2 {+-} 0.2 mrad per track and N{sub {gamma}} 15.7 {+-} 0.1 at {theta}{sub dip} = 20 angle and 0 transmission in the bar. The analysis of the first cosmic data collected by the BABAR detector has allowed to study the DIRC in its final configuration. Among all the results obtained, we give the following ones: {sigma}({theta}{sub c}) = 10.09 {+-} 0.06 mrad per photon, {sigma}({theta}{sub c}) = 4.71 {+-} 0.14 mrad per track and N{sub {gamma}} 35.2 {+-} 3.8 at {theta}{sub dip} = 20 angle and 0 transmission in the bar. The extrapolation to the real condition of BABAR for all these results shows that the DIRC will run with performances similar to the nominal values. A detailed study of the background shows that, even though it will not be negligible, it will not compromise the DIRC performances in BABAR.

  17. The OSMOND detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Dalgliesh, R. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Duxbury, D.M., E-mail: dom.duxbury@stfc.ac.uk [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Holt, S.A.; Kinane, C.J. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Marsh, A.S. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Rhodes, N.J.; Schooneveld, E.M. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Spill, E.J.; Stephenson, R. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom)

    2013-01-11

    The development and testing of the Off Specular MicrOstrip Neutron Detector (OSMOND) is described. Based on a microstrip gas chamber the aim of the project was to produce a high counting rate detector capable of replacing the existing rate limited scintillator detectors currently in use on the CRISP reflectometer for off specular reflectometry experiments. The detector system is described together with results of neutron beam tests carried out at the ISIS spallation neutron source.

  18. Application of gas chromatography/flame ionization detector-based metabolite fingerprinting for authentication of Asian palm civet coffee (Kopi Luwak).

    Science.gov (United States)

    Jumhawan, Udi; Putri, Sastia Prama; Yusianto; Bamba, Takeshi; Fukusaki, Eiichiro

    2015-11-01

    Development of authenticity screening for Asian palm civet coffee, the world-renowned priciest coffee, was previously reported using metabolite profiling through gas chromatography/mass spectrometry (GC/MS). However, a major drawback of this approach is the high cost of the instrument and maintenance. Therefore, an alternative method is needed for quality and authenticity evaluation of civet coffee. A rapid, reliable and cost-effective analysis employing a universal detector, GC coupled with flame ionization detector (FID), and metabolite fingerprinting has been established for discrimination analysis of 37 commercial and non-commercial coffee beans extracts. gas chromatography/flame ionization detector (GC/FID) provided higher sensitivity over a similar range of detected compounds than GC/MS. In combination with multivariate analysis, GC/FID could successfully reproduce quality prediction from GC/MS for differentiation of commercial civet coffee, regular coffee and coffee blend with 50 wt % civet coffee content without prior metabolite details. Our study demonstrated that GC/FID-based metabolite fingerprinting can be effectively actualized as an alternative method for coffee authenticity screening in industries. Copyright © 2015. Published by Elsevier B.V.

  19. High spatial and time resolutions with gas ionization detectors; Hautes resolutions en position et temps avec des detecteurs gazeux a ionisation

    Energy Technology Data Exchange (ETDEWEB)

    Pouthas, J

    2001-09-01

    This document presents the principles and the characteristics of the gaseous ionisation detectors used in position and timing measurements. The first two parts recall the main notions (electron and ion motions, gaseous amplification, signal formation) and their applications to the proportional counter and the wire chamber. The explanation of the signal formation makes use of the Ramo theorem. The third part is devoted to the different types of wire chambers: drift or cathode strip chambers, TPC (time projection chamber). Some aspects on construction and ageing are also presented. Part 4 is on the detectors in which the multiplication is performed by a 'Parallel Plate' system (PPAC, Pestov counter). Special attention is paid to the RPCs (Resistive Plate Chambers) and their timing resolutions. Part 5 concentrates on 'Micro-pattern detectors' which use different kinds of microstructure for gaseous amplification. The new detectors MICROMEGAS, CAT (compteur a trous) and GEM (gas electron multiplier) and some of their applications are presented. The last part is a bibliography including some comments on the documents. (author)

  20. Determination of phosphorous in cannabis by neutron activation analysis - measurement of 32P Cerenkov radiation by liquid scintillaton spectrometer

    International Nuclear Information System (INIS)

    Shinogi, M.; Mori, I.

    1977-05-01

    Thermal neutron activaton analysis with measurement of 32 P Cerenkov radiation by liquid scintillation spectrometer was used to determine phosphorus in cannabis. After irradiation of the sample, wet ashing was carried out with conc. nitric acid and 70% perchloric acid. The solution in l M perchloric acid transferred to an inorganic ion-exchange column containing acid aluminium oxide and phosphorus was quantitatively eluted with 1M hydrofluoric acid. The 32 P radioactivity of each fraction of the eluate was counted with Cerenkov radiation by a liquid scintillation spectrometer from 2 to 7 weeks after the irradiation. The activity curve decayed with 32 P half-life. The isotope channel ratio technique was applied for the quench correction. The optimal experimental conditions for chemical separation of phosphorus and for measuring the 32 P Cerenkov radiation were also examined. (Author)

  1. Compound Semiconductor Radiation Detector

    International Nuclear Information System (INIS)

    Kim, Y. K.; Park, S. H.; Lee, W. G.; Ha, J. H.

    2005-01-01

    In 1945, Van Heerden measured α, β and γ radiations with the cooled AgCl crystal. It was the first radiation measurement using the compound semiconductor detector. Since then the compound semiconductor has been extensively studied as radiation detector. Generally the radiation detector can be divided into the gas detector, the scintillator and the semiconductor detector. The semiconductor detector has good points comparing to other radiation detectors. Since the density of the semiconductor detector is higher than that of the gas detector, the semiconductor detector can be made with the compact size to measure the high energy radiation. In the scintillator, the radiation is measured with the two-step process. That is, the radiation is converted into the photons, which are changed into electrons by a photo-detector, inside the scintillator. However in the semiconductor radiation detector, the radiation is measured only with the one-step process. The electron-hole pairs are generated from the radiation interaction inside the semiconductor detector, and these electrons and charged ions are directly collected to get the signal. The energy resolution of the semiconductor detector is generally better than that of the scintillator. At present, the commonly used semiconductors as the radiation detector are Si and Ge. However, these semiconductor detectors have weak points. That is, one needs thick material to measure the high energy radiation because of the relatively low atomic number of the composite material. In Ge case, the dark current of the detector is large at room temperature because of the small band-gap energy. Recently the compound semiconductor detectors have been extensively studied to overcome these problems. In this paper, we will briefly summarize the recent research topics about the compound semiconductor detector. We will introduce the research activities of our group, too

  2. The coulometric electron capture detector and its application to the selected freons in water and air. Part of a coordinated programme on the analysis of organic compounds by electron capture gas chromatography

    International Nuclear Information System (INIS)

    Lasa, J.

    1981-01-01

    In developing the use of Freon-11 and Freon-12 as environmental tracers in aeronomy, oceanography and hydrology electron capture gas chromatography was used to measure the concentration changes. A detector in the coulometric mode was designed and operated as a solute switch. The detection limit was in the order of 0.2x10 -12 g for a modified head space method in handling aqueous samples. Theoretical analysis of the detector design and the effects of factors including pulsing period, flowrates of carrier gas and the radioactivity of the detector source were discussed and confirmed experimentally

  3. Surface-coupling of Cerenkov radiation from a modified metallic metamaterial slab via Brillouin-band folding.

    Science.gov (United States)

    Bera, Anirban; Barik, Ranjan Kumar; Sattorov, Matlabjon; Kwon, Ohjoon; Min, Sun-Hong; Baek, In-Keun; Kim, Seontae; So, Jin-Kyu; Park, Gun-Sik

    2014-02-10

    Metallic metamaterials with positive dielectric responses are promising as an alternative to dielectrics for the generation of Cerenkov radiation [J.-K. So et al., Appl. Phys. Lett. 97(15), 151107 (2010)]. We propose here by theoretical analysis a mechanism to couple out Cerenkov radiation from the slab surfaces in the transverse direction. The proposed method based on Brillouin-zone folding is to periodically modify the thickness of the metamaterial slab in the axial direction. Moreover, the intensity of the surface-coupled radiation by this mechanism shows an order-of-magnitude enhancement compared to that of ordinary Smith-Purcell radiation.

  4. Enhanced Cerenkov second-harmonic generation in a planar nonlinear waveguide that reproduces a one-dimensional photonic bandgap structure

    International Nuclear Information System (INIS)

    Pezzetta, D.; Sibilia, C.; Bertolotti, M.; Ramponi, R.; Osellame, R.; Marangoni, M.; Haus, J. W.; Scalora, M.; Bloemer, M. J.; Bowden, C. M.

    2002-01-01

    Second-harmonic generation in the Cerenkov configuration is investigated under conditions for which the use of a linear grating fabricated on top of the waveguide reproduces a photonic bandgap structure. The fundamental mode of the guide at the fundamental frequency is tuned at the photonic band-edge resonance, thus producing great confinement and enhancement of the electromagnetic field inside the structure. The conversion efficiency achieved in both the forward and the backward directions is at least 1 order of magnitude greater than that of a conventional Cerenkov emission in a waveguide of the same length. An analysis of the tolerances of the grating period on the conversion efficiency is presented

  5. Determination of phosphorus-32 in wet-digested plant leaves by Cerenkov counting

    International Nuclear Information System (INIS)

    Wahid, P.A.; Kamalam, N.V.; Sankar, S.J.

    1985-01-01

    A method of determination of 32 P activity in leaf samples by Cerenkov counting technique is described. The method involves wet digestion of oven-dried leaves with 1:1 nitric-perchloric acid mixture followed by transferring the digest into a scintillation counting vial with distilled water upto a final volume of 20 mL, and determining the activity in a liquid scintillation system. Reproducible count rates can be obtained if the vials are counted after 4h allowing the silica in the digest to settle. (author)

  6. Monte Carlo simulations support non-Cerenkov radioluminescence production in tissue

    Science.gov (United States)

    Ackerman, Nicole L.; Boschi, Federico; Spinelli, Antonello E.

    2017-08-01

    There is experimental evidence for the production of non-Cerenkov radioluminescence in a variety of materials, including tissue. We constructed a Geant4 Monte Carlo simulation of the radiation from P32 and Tc99m interacting in chicken breast and used experimental imaging data to model a scintillation-like emission. The same radioluminescence spectrum is visible from both isotopes and cannot otherwise be explained through fluorescence or filter miscalibration. We conclude that chicken breast has a near-infrared scintillation-like response with a light yield three orders of magnitude smaller than BGO.

  7. Linear theory of a dielectric-loaded rectangular Cerenkov maser with a sheet electron beam

    International Nuclear Information System (INIS)

    Chen Ye; Wan Xiao-Sheng; Zhao Ding; Liu Wen-Xin; Wang Yong

    2012-01-01

    A three-dimensional model of a dielectric-loaded rectangular Cerenkov maser with a sheet electron beam for the beam-wave interaction is proposed. Based on this model, the hybrid-mode dispersion equation is derived with the Borgnis potential function by using the field-matching method. Its approximate solution is obtained under the assumption of a dilute electron beam. By using the Ansoft high frequency structural simulator (HFSS) code, the electromagnetic field distribution in the interaction structure is given. Through numerical calculations, the effects of beam thickness, beam and dielectric-layer gap distance, beam voltage, and current density on the resonant growth rate are analysed in detail

  8. Pressure Drop Versus Flow Rate Analysis of the Limited Streamer Tube Gas System of the BaBar Muon Detector Upgrade

    International Nuclear Information System (INIS)

    Yi, M.

    2004-01-01

    It has been proposed that Limited Streamer Tubes (LST) be used in the current upgrade of the muon detector in the BaBar detector. An LST consists of a thin silver plated wire centered in a graphite-coated cell. One standard LST tube consists of eight such cells, and two or three such tubes form an LST module. Under operation, the cells are filled with a gas mixture of CO 2 , argon and isobutane. During normal operation of the detector, the gas will be flushed out of the system at a constant low rate of one volume change per day. During times such as installation, however, it is often desired to flush and change the LST gas volumes very rapidly, leading to higher than normal pressure which may damage the modules. This project studied this pressure as a function of flow rate and the number of modules that are put in series in search of the maximal safe flow rate at which to flush the modules. Measurements of pressure drop versus flow rate were taken using a flow meter and a pressure transducer on configurations of one to five modules put in series. Minimal Poly-Flo tubing was used for all connections between test equipment and modules. They contributed less than 25% to all measurements. A ratio of 0.00022 ± 0.00001 mmHg per Standard Cubic Centimeter per Minute (SCCM) per module was found, which was a slight overestimate since it included the contributions from the tubing connections. However, for the purpose of finding a flow rate at which the modules can be safely flushed, this overestimate acts as a safety cushion. For a standard module with a volume of 16 liters and a known safe overpressure of 2 inches of water, the ratio translates into a flow rate of 17000 ± 1000SCCM and a time requirement of 56 ± 5 seconds to flush an entire module

  9. Design and construction of a uniform magnetic field generator for a 32 channel cosmic ray detector

    Science.gov (United States)

    Herrera-Guzman, K. N.; Gutierrez-Sanchez, R. A.; Felix, J.; Arceo, L. J.; Araujo, C.

    2017-10-01

    The trajectory of a particle can be measured if some points of its track are known. This is applied to any kind of particle, including cosmic rays. We have designed and built a device for this purpose. We present the design, construction and characterization of a uniform magnetic field generator system in a finite volume. An array of Cerenkov detectors will be placed inside of it for determining the cosmic rays charge and to reconstruct their trajectories.

  10. Investigation of Cerenkov counting of environmental strontium-90

    International Nuclear Information System (INIS)

    Reynolds, S.A.; Eldridge, J.S.

    1979-01-01

    A typical liquid scintillation counter was evaluated for detection of low levels of 90 Sr-Y. A blank of about 5 cpm and 90 Y efficiency of 42% were obtained for 20-ml samples. The corresponding minimum detectable concentration for a 100-minute count is 0.03 pCi/ml, so that measurement of water samples can readily be made at the maximum permissible concentration for 90 Sr, 0.3 pCi/ml. The efficiency for 90 Sr is less than 0.4%, 1.4% for 137 Cs, and less than 0.04% for gamma-emitting 85 Sr, a useful tracer. Some data for 90 Y efficiencies and blanks are given for other liquid scintillation counters. Chemical treatments are necessary in some cases to concentrate 90 Sr-Y, to remove colored substances which cause quenching, or to eliminate interfering radionuclides. However, the manipulations need not be as elaborate as in conventional radiochemical analysis methods for 90 Sr. Ferric ion (yellow) quenches at the 5 ppM level, but the interference can be eliminated by adding a reducing agent. The Rn daughter 214 Bi, an interfering radionuclide, disappears by decay in 2-3 hours after removal of Rn by sweeping with air or gas. Concentration-separation methods studied have included precipitation and ion exchange

  11. Study of various photomultiplier tubes with muon beams and Cerenkov light produced in electron showers

    International Nuclear Information System (INIS)

    2010-01-01

    The PMTs of the CMS Hadron Forward calorimeter were found to generate a large size signal when their windows were traversed by energetic charged particles. This signal, which is due to Cerenkov light production at the PMT window, could interfere with the calorimeter signal and mislead the measurements. In order to find a viable solution to this problem, the response of four different types of PMTs to muons traversing their windows at different orientations is measured at the H2 beam-line at CERN. Certain kinds of PMTs with thinner windows show significantly lower response to direct muon incidence. For the four anode PMT, a simple and powerful algorithm to identify such events and recover the PMT signal using the signals of the quadrants without window hits is also presented. For the measurement of PMT responses to Cerenkov light, the Hadron Forward calorimeter signal was mimicked by two different setups in electron beams and the PMT performances were compared with each other. Superior performance of particular PMTs was observed.

  12. Pixel-based parametric source depth map for Cerenkov luminescence imaging

    International Nuclear Information System (INIS)

    Altabella, L.; Spinelli, A.E.; Boschi, F.

    2016-01-01

    Optical tomography represents a challenging problem in optical imaging because of the intrinsically ill-posed inverse problem due to photon diffusion. Cerenkov luminescence tomography (CLT) for optical photons produced in tissues by several radionuclides (i.e.: 32P, 18F, 90Y), has been investigated using both 3D multispectral approach and multiviews methods. Difficult in convergence of 3D algorithms can discourage to use this technique to have information of depth and intensity of source. For these reasons, we developed a faster 2D corrected approach based on multispectral acquisitions, to obtain source depth and its intensity using a pixel-based fitting of source intensity. Monte Carlo simulations and experimental data were used to develop and validate the method to obtain the parametric map of source depth. With this approach we obtain parametric source depth maps with a precision between 3% and 7% for MC simulation and 5–6% for experimental data. Using this method we are able to obtain reliable information about the source depth of Cerenkov luminescence with a simple and flexible procedure

  13. Rapid determination of strontium-89 and strontium-90 in food and environmental samples by Cerenkov counting

    International Nuclear Information System (INIS)

    Melin, Judith; Suomela, Jorma

    1995-01-01

    The method has been developed for emergency situations. Minimum detectable concentrations of 5 Bq/liter, kilogram of strontium-89 and strontium-90 respectively is achievable in the presence of nuclides considered to be released under accidental conditions. Result on the strontium-89 and strontium-90 content in a sample can be obtained within 12 hours. One technician can easily handle 8-10 samples during a working day of eight hours. The determination of the strontium isotopes is accomplished by monitoring the Cerenkov radiation from strontium-89 and yttrium-90 in a liquid scintillation counter. The latter is the daughter product of strontium-90. Prior to the Cerenkov counting the sample is separated from interfering nuclides by oxalate precipitation, chromate precipitation and HDEHP-extraction. The method has to be further improved and evaluated with respect to different soil types such as forest mineral soil layers, agricultural soils and pastures. Furthermore, the decontamination procedure should be evaluated for a sample containing freshly irradiated uranium. (author)

  14. The UCLA/SLAC Ultra-High Gradient Cerenkov Wakefield Accelerator Experiment

    CERN Document Server

    Thompson, Matthew C; Hogan, Mark; Ischebeck, Rasmus; Muggli, Patric; Rosenzweig, James E; Scott, A; Siemann, Robert; Travish, Gil; Walz, Dieter; Yoder, Rodney

    2005-01-01

    An experiment is planned to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range. This new UCLA/SLAC collaboration will take advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., sz = 20 μm at Q = 3 nC). The electron beam will be focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 μm / OD = 325 μm and ID = 100 μm / OD = 325 μm. The pulse length of the electron beam will be varied in order to alter the accelerating gradient and probe the breakdown threshold of the dielectric structures. In addition to breakdown studies, we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain information about the strength of the accelerating fields. Status and progress on the experiment are reported.

  15. Single gas chromatography method with nitrogen phosphorus detector for urinary cotinine determination in passive and active smokers

    Directory of Open Access Journals (Sweden)

    Lusiane Malafatti

    2010-12-01

    Full Text Available Nicotine is a major addictive compound in cigarettes and is rapidly and extensively metabolized to several metabolites in humans, including urinary cotinine, considered a biomarker due to its high concentration compared to other metabolites. The aim of this study was to develop a single method for determination of urinary cotinine, in active and passive smokers, by gas chromatography with a nitrogen phosphorus detector (GC-NPD. Urine (5.0 mL was extracted with 1.0 mL of sodium hydroxide 5 mol L-1, 5.0 mL of chloroform, and lidocaine used as the internal standard. Injection volume was 1 μL in GC-NPD. Limit of quantification was 10 ng mL-1. Linearity was evaluated in the ranges 10-1000 ng mL-1 and 500-6000 ng mL-1, with determination coefficients of 0.9986 and 0.9952, respectively. Intra- and inter-assay standard relative deviations were lower than 14.2 %, while inaccuracy (bias was less than +11.9%. The efficiency of extraction was greater than 88.5%. Ruggedness was verified, according to Youden's test. Means of cotinine concentrations observed were 2,980 ng mL-1 for active smokers and 132 ng mL-1, for passive smokers. The results revealed that satisfactory chromatographic separation between the analyte and interferents was obtained with a ZB-1 column. This method is reliable, precise, linear and presented ruggedness in the range evaluated. The results suggest that it can be applied in routine analysis for passive and active smokers, since it is able to quantify a wide range of cotinine concentrations in urine.A nicotina é uma substância presente no cigarro capaz de causar dependência, sendo biotransformada em vários metabólitos nos seres humanos, dentre eles a cotinina urinária, que é considerada um indicador biológico de exposição à nicotina, devido a suas altas concentrações, comparado a outras matrizes. Assim, o objetivo deste estudo foi desenvolver um único método para determinação de cotinina urinária, em amostras de

  16. Evaluation of a novel helium ionization detector within the context of (low-)flow modulation comprehensive two-dimensional gas chromatography.

    Science.gov (United States)

    Franchina, Flavio A; Maimone, Mariarosa; Sciarrone, Danilo; Purcaro, Giorgia; Tranchida, Peter Q; Mondello, Luigi

    2015-07-10

    The present research is focused on the use and evaluation of a novel helium ionization detector, defined as barrier discharge ionization detector (BID), within the context of (low-)flow modulation comprehensive two-dimensional gas chromatography (FM GC×GC). The performance of the BID device was compared to that of a flame ionization detector (FID), under similar FM GC×GC conditions. Following development and optimization of the FM GC×GC method, the BID was subjected to fine tuning in relation to acquisition frequency and discharge flow. Moreover, the BID performance was measured and compared to that of the FID, in terms of extra-column band broadening, sensitivity and dynamic range. The comparative study was carried out by using standard compounds belonging to different chemical classes, along with a sample of diesel fuel. Advantages and disadvantages of the BID system, also within the context of FM GC×GC, are critically discussed. In general, the BID system was characterized by a more limited dynamic range and increased sensitivity, compared to the FID. Additionally, BID and FID contribution to band broadening was found to be similar under the operational conditions applied. Particular attention was devoted to the behaviour of the FM GC×GC-BID system toward saturated and aromatic hydrocarbons, for a possible future use in the field of mineral-oil food contamination research. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Data acquisition and online control system for new gas-electron multiplier detectors in the endcap muon system of the CMS experiment

    CERN Document Server

    Ruiz Alvarez, Jose David

    2016-01-01

    A new data acquisition and on-line control system is being developed for gas-electron multiplier (GEM) detectors which will be installed in the forward region (1.6 \\( < \\eta < \\) 2.2) of the CMS muon spectrometer during the 2nd long shutdown of the LHC, planned for the period 2018-2019. A prototype system employs the TOTEM VFAT2 ASIC that will eventually be replaced with the VFAT3 ASIC, under development. The front-end ASIC communicates over printed circuit lines with an intermediate on-detector board called the opto-hybrid. Data, trigger, and control information is transmitted via optical fiber between the opto-hybrid and an off-detector readout system using micro-TCA technology. On-line software, implemented in the CMS XDAQ framework, includes applications for latency and HV scans, and system management. We report on the operational status of the prototype system that has been tested using cosmic ray muons and extracted high-energy particle beams. This work is preparatory for the operation of a prot...

  18. New gas electron-multiplier detectors for the endcap muon system of the CMS experiment at the high-luminosity LHC design and prototype performance

    CERN Document Server

    Gruchala, Marek Michal

    2016-01-01

    The high luminosity LHC will require new detectors in the CMS endcap muon system to suppress the trigger rate of background events, to maintain high trigger efficiency for low transverse momentum muons, to enhance the robustness of muon detection in the high-flux environment of the endcap, and to extend the geometrical acceptance. We report on the design and recent progress towards implementing a new system of large-area, triple-foil gas electron-multiplier (GEM) detectors that will be installed in the first three of five muon detector stations in each endcap, the first station being closest to the interaction point. The first station will extend the geometric acceptance in pseudo-rapidity to eta lt 3.0 from the current limit of eta lt 2.4. The second and third stations will enhance the performance in the range 1.6 lt eta lt 2.4. We describe the design of the chambers and readout electronics and report on the performance of prototype systems in tests with cosmic ray muons, high-energy particlebeams, a...

  19. A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi [Soonchunhyang Univ., Asan (Korea, Republic of)

    2016-10-15

    In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research.

  20. A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

    International Nuclear Information System (INIS)

    Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi

    2016-01-01

    In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research

  1. Near-Infrared Quantum Dot and (89)Zr Dual-Labeled Nanoparticles for in Vivo Cerenkov Imaging

    NARCIS (Netherlands)

    Zhao, Yiming; Shaffer, Travis M.; Das, Sudeep; Pérez-Medina, Carlos; Mulder, Willem J. M.; Grimm, Jan

    2017-01-01

    Cerenkov luminescence (CL) is an emerging imaging modality that utilizes the light generated during the radioactive decay of many clinical used isotopes. Although it is increasingly used for background-free imaging and deep tissue photodynamic therapy, in vivo applications of CL suffer from limited

  2. Multi-Detector CT Findings of the Normal Appendix in Children: Evaluation of the Position, Diameter, and Presence or Absence of Intraluminal Gas

    Energy Technology Data Exchange (ETDEWEB)

    Park, Woon Ju; Kim, Jong Chul [Dept. of Radiology, Chungnam National University College of Medicine, Daejeon (Korea, Republic of)

    2011-08-15

    To assess the usefulness of multi-detector CT (MDCT) with multiplanar reformations (MPR) for the evaluation of the position, diameter and presence or absence of intraluminal gas in the normal appendix in children. From 2007 to 2010, we retrospectively analyzed the MDCT images of normal appendices in 133 children, and evaluated the position, diameter, and presence or absence of intraluminal gas in the appendix. Among the 133 appendices, type I (postileal and medial paracecal position) was found in 64 children, type II (subcecal position) in 22, type III (retrocecal and retrocolic/laterocolic position) in 15, type IV (preileal and medial colic position) in 16, and type V (lower pelvic position) in 16 children. The mean diameter was 5.8 mm {+-} 1.2 (SD) (range; 3.2-8.7 mm). There was a high correlation between the appendiceal diameter and age (p = 0.000).There was no statistically significant difference in the appendiceal diameter between boys and girls (p = 0.470). Intraluminal gas was found in 115 appendices and there was no statistically significant correlation between the appendiceal diameter and intraluminal gas (p = 0.502). The MDCT with MPR was useful for the evaluation of the normal appendices in children. The procedure may be useful for the diagnosis of equivocal or unusual appendicitis in children.

  3. Performance of a C4F8O gas radiator ring imaging Cherenkov detector using multi-anode photomultiplier tubes

    International Nuclear Information System (INIS)

    Artuso, M.; Boulahouache, C.; Blusk, S.; Butt, J.; Dorjkhaidav, O.; Menaa, N.; Mountain, R.; Muramatsu, H.; Nandakumar, R.; Randrianarivony, K.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J.C.; Zhang, K.

    2006-01-01

    We report on tests of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3-m-long gaseous C 4 F 8 O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3 to 70GeV/c for the BTeV experiment

  4. Cerenkov emission of acoustic phonons electrically generated from three-dimensional Dirac semimetals

    Energy Technology Data Exchange (ETDEWEB)

    Kubakaddi, S. S., E-mail: sskubakaddi@gmail.com [Department of Physics, Karnatak University, Dharwad 580 003, Karnataka (India)

    2016-05-21

    Cerenkov acoustic phonon emission is theoretically investigated in a three-dimensional Dirac semimetal (3DDS) when it is driven by a dc electric field E. Numerical calculations are made for Cd{sub 3}As{sub 2} in which mobility and electron concentration are large. We find that Cerenkov emission of acoustic phonons takes place when the electron drift velocity v{sub d} is greater than the sound velocity v{sub s}. This occurs at small E (∼few V/cm) due to large mobility. Frequency (ω{sub q}) and angular (θ) distribution of phonon emission spectrum P(ω{sub q}, θ) are studied for different electron drift velocities v{sub d} (i.e., different E) and electron concentrations n{sub e}. The frequency dependence of P(ω{sub q}, θ) shows a maximum P{sub m}(ω{sub q}, θ) at about ω{sub m} ≈ 1 THz and is found to increase with the increasing v{sub d} and n{sub e}. The value of ω{sub m} shifts to higher region for larger n{sub e}. It is found that ω{sub m}/n{sub e}{sup 1/3} and P{sub m}(ω{sub q}, θ)/n{sub e}{sup 2/3} are nearly constants. The latter is in contrast with the P{sub m}(ω{sub q}, θ)n{sub e}{sup 1/2 }= constant in conventional bulk semiconductor. Each maximum is followed by a vanishing spectrum at nearly “2k{sub f} cutoff,” where k{sub f} is the Fermi wave vector. Angular dependence of P(ω{sub q}, θ) and the intensity P(θ) of the phonon emission shows a maximum at an emission angle 45° and is found to increase with increasing v{sub d}. P(θ) is found to increase linearly with n{sub e} giving the ratio P(θ)/(n{sub e}v{sub d}) nearly a constant. We suggest that it is possible to have the controlled Cerenkov emission and generation of acoustic phonons with the proper choice of E, θ, and n{sub e}. 3DDS with large n{sub e} and mobility can be a good source of acoustic phonon generation in ∼THz regime.

  5. Pulsed beam dosimetry using fiber-coupled radioluminescence detectors

    DEFF Research Database (Denmark)

    Andersen, Claus Erik

    2012-01-01

    The objective of this work was to review and discuss the potential application of fiber-coupled radioluminescence detectors for dosimetry in pulsed MV photon beams. Two types of materials were used: carbon-doped aluminium oxide (Al2O3:C) and organic plastic scintillators. Special consideration...... was given to the discrimination between radioluminescence signals from the phosphors and unwanted light induced in the optical fiber cables during irradiation (Cerenkov and fluorescence). New instrumentation for dose-per-pulse measurements with organic plastic scintillators was developed....

  6. Cosmic ray studies with the Soudan 2 detector

    International Nuclear Information System (INIS)

    Ruddick, Keith

    1994-01-01

    We will describe attempts to measure the elemental composition of the primary cosmic rays using muons observed deep underground in coincidence with detectors on the surface of the earth. A proportional tube array has been used to measure shower size at the surface and we have recently constructed a Cerenkov array which will give a more direct measurement of primary cosmic ray energy. We will also present results from an all-sky survey obtained from the trajectories of underground muons ohserved over a four year period. ((orig.))

  7. Measurement of atmospheric neutrino composition with the IMB-3 detector

    International Nuclear Information System (INIS)

    Casper, D.; Becker-Szendy, R.; Bratton, C.B.; Cady, D.R.; Claus, R.; Dye, S.T.; Gajewski, W.; Goldhaber, M.; Haines, T.J.; Halverson, P.G.; Jones, T.W.; Kielczewska, D.; Kropp, W.R.; Learned, J.G.; LoSecco, J.M.; McGrew, C.; Matsuno, S.; Matthews, J.; Mudan, M.S.; Price, L.; Reines, F.; Schultz, J.; Sinclair, D.; Sobel, H.W.; Stone, J.L.; Sulak, L.R.; Svoboda, R.; Thornton, G.; van der Velde, J.C.; The University of Michigan, Ann Arbor, Michigan 48109 Brookhaven National; Laboratory, Upton, New York 11973; Boston University, Boston, Massachusetts 02215; The University of Hawaii, Honolulu, Hawaii 96822 University College, London, WC1E F6BT, United Kingdom; Warsaw University, Warsaw, Poland; Cleveland State University, Cleveland, Ohio 44115; The University of Notre Dame, Notre Dame, Indiana 46556; Lousiana State University, Baton Rouge, Lousisiana 70803; The University of Maryland, College Park, Maryland 20742)

    1991-01-01

    The atmospheric neutrino flux is measured using a 3.4-kt yr exposure of the IMB-3 detector. Single-ring events are classified as showering or nonshowering using the geometry of the Cerenkov pattern. A simulation of neutrino interactions and three models of atmospheric neutrino production are used to predict the composition of the sample. Showering-nonshowering character is strongly correlated with the flavor of the neutrino parent. In the lepton momentum range p<1500 MeV/c, we find that nonshowering events comprise [41±3±2syst]% of the total. The fraction expected is [51±5(syst)]%

  8. The Micro Wire Detector

    International Nuclear Information System (INIS)

    Adeva, B.; Gomez, F.; Pazos, A.; Pfau, R.; Plo, M.; Rodriguez, J.M.; Vazquez, P.; Labbe, J.C.

    1999-01-01

    We present the performance of a new proportional gas detector. Its geometry consists of a cathode plane with 70x70 μm 2 apertures, crossed by 25 μm anode strips to which it is attached by 50 μm kapton spacers. In the region where the avalanche takes place, the anode strips are suspended in the gas mixture as in a standard wire chamber. This detector exhibits high rate capability and large gains, introducing very little material. (author)

  9. Gas

    International Nuclear Information System (INIS)

    1996-01-01

    The French government has decided to modify the conditions of extension of local natural gas authorities to neighbouring districts. The European Union is studying the conditions of internal gas market with the objective of more open markets although considering public service requirements

  10. Visualization of Cerenkov radiation and the fields of a moving charge

    International Nuclear Information System (INIS)

    Pfeifer, Robert N C; Nieminen, Timo A

    2006-01-01

    For some physics students, the concept of a particle travelling faster than the speed of light holds endless fascination, and Cerenkov radiation is a visible consequence of a charged particle travelling through a medium at locally superluminal velocities. The Heaviside-Feynman equations for calculating the magnetic and electric fields of a moving charge have been known for many decades, but it is only recently that the computing power to plot the fields of such a particle has become readily available for student use. This paper investigates and illustrates the calculation of Maxwell's D field in homogeneous isotropic media for arbitrary, including superluminal, constant velocity, and uses the results as a basis for discussing energy transfer in the electromagnetic field

  11. Methodology for estimation of 32P in bioassay samples by Cerenkov counting

    International Nuclear Information System (INIS)

    Wankhede, Sonal; Sawant, Pramilla D.; Yadav, R.K.B.; Rao, D.D.

    2016-01-01

    Radioactive phosphorus ( 32 P) as phosphate is used to effectively reduce bone pain in terminal cancer patients. Several hospitals in India carry out this palliative care procedure on a regular basis. Thus, production as well as synthesis of 32 P compounds has increased over the years to meet this requirement. Monitoring of radiation workers handling 32 P compounds is important for further strengthening of radiological protection program at processing facility. 32 P being a pure beta emitter (β max = 1.71 MeV, t 1/2 = 14.3 d), bioassay is the preferred individual monitoring technique. Method standardized at Bioassay Lab, Trombay, includes estimation of 32 P in urine by co-precipitation with ammonium phosphomolybdate (AMP) followed by gross beta counting. In the present study, feasibility of Cerenkov counting for detection of 32 P in bioassay samples was explored and the results obtained were compared with the gross beta counting technique

  12. Parametric effect of a spatially periodic voltage depression on operation of Cerenkov sources of electromagnetic radiation

    International Nuclear Information System (INIS)

    Nusinovich, G.S.; Vlasov, A.N.

    1994-01-01

    In microwave sources of coherent Cerenkov radiation the electrons usually propagate near the rippled wall of a slow-wave structure. These ripples cause the periodic modulation of electron potential depression, and therefore, lead to periodic modulation of electron axial velocities. Since the period of this electrostatic pumping is the period of the slow-wave structure the parametric coupling of electrons to originally nonsynchronous spatial harmonics of the microwave field may occur. This effect can be especially important for backward-wave oscillators (BWO's) driven by high current, relativistic electron beams. In the paper both linear and nonlinear theories of the relativistic resonant BWO with periodic modulation of electron axial velocities are developed and results illustrating the evolution of the linear gain function and the efficiency of operation in the large-signal regime are presented

  13. Field theory of a terahertz staggered double-grating arrays waveguide Cerenkov traveling wave amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wenqiu; He, Fangming [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Zicheng; Luo, Jirun; Zhao, Ding; Liu, Qinglun [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-04-15

    Based on a rectilinear sheet electron beam propagating through the tunnel of a staggered double-grating arrays waveguide (SDGAW) slow-wave structure (SWS), a three dimensional field theory for describing the modes and the beam-wave interaction is presented, in which the higher order terms inside the grooves are retained. The fields' distribution and the conductivity losses are also calculated utilizing the theoretical model. With the optimized parameters of the SWS and the electron beam, a 1 THz SDGAW Cerenkov traveling wave amplifier may obtain a moderate net gain (the peak gain is 12.7 dB/cm) and an ultra 3 dB wideband (0.19 THz) considering the serious Ohmic losses. The theoretical results have been compared with those calculated by 3D HFSS code and CST STUDIO particle-in-cell simulations.

  14. Gamma-ray burst observations with new generation imaging atmospheric Cerenkov Telescopes in the FERMI era

    International Nuclear Information System (INIS)

    Covino, S.; Campana, S.; Garczarczyk, M.; Galante, N.; Gaug, M.; Antonelli, A.; Bastieri, D.; Longo, F.; Scapin, V.

    2009-01-01

    After the launch and successful beginning of operations of the FERMI satellite, the topics related to high-energy observations of gamma-ray bursts have obtained a considerable attention by the scientific community. Undoubtedly, the diagnostic power of high-energy observations in constraining the emission processes and the physical conditions of gamma-ray burst is relevant. We briefly discuss how gamma-ray burst observations with ground-based imaging array Cerenkov telescopes, in the GeV-TeV range, can compete and cooperate with FERMI observations, in the MeV-GeV range, to allow researchers to obtain a more detailed and complete picture of the prompt and afterglow phases of gamma-ray bursts.

  15. Multimodality imaging of 131I uptake in nude mice thyroid based on Cerenkov radiation

    International Nuclear Information System (INIS)

    Hu Zhenhua; Liang Jimin; Qu Xiaochao; Yang Weidong; Ma Xiaowei; Wang Jing; Tian Jie

    2012-01-01

    Objective: To perform the multimodality 131 I thyroid imaging using Cerenkov luminescence tomography (CLT) and gamma imaging, and to compare the results of CLT and gamma imaging. Methods The nude mice (n=4, mass: (21 ±3) g) were injected with 1.67 ×10 7 Bq 131 I. CLT and gamma imaging were acquired at 0.5, 3, 12 and 24 h after the injection. Three-dimensional biodistribution of 131 I uptake in thyroid was reconstructed using Cerenkov source reconstruction method based on the diffusion equation (DE), and the reconstructed power of 131 I in different acquisition time points was obtained. Additionally, the ROIs were drawn over the gamma images of the mouse neck, and the counts were read. The correlation between the reconstructed power of CLT and gamma ray counts of gamma imaging was analyzed. Results: The power of 131 I uptake in thyroid at 0.5, 3, 12 and 24 h were 7.80 ×10 -13 , 1.62×10 -12 , 2.20×10 -12 and 2.68 × 10 -12 W, respectively. CLT results showed that reconstructed power increased with the increasing of acquisition time. Gamma imaging results indicated that 131 I uptake decreased in abdomen and increased in thyroid with the collection time. The results of CLT were consistent with that of gamma imaging (r 2 =0.7620, P<0.05). Conclusion: CLT has the potential to identify and monitor functioning thyroid tissue at before and (or) after 131 I treatment. (authors)

  16. Smoke detectors

    International Nuclear Information System (INIS)

    Fung, C.K.

    1981-01-01

    This describes a smoke detector comprising a self-luminous light source and a photosensitive device which is so arranged that the light source is changed by the presence of smoke in a detecting region. A gaseous tritium light source is used. This consists of a borosilicate glass bulb with an internal phosphor coating, filled with tritium gas. The tritium emits low energy beta particles which cause the phosphor to glow. This is a reliable light source which needs no external power source. The photosensitive device may be a phototransistor and may drive a warning device through a directly coupled transistor amplifier. (U.K.)

  17. Determination of polycyclic aromatic hydrocarbons in palm oil mill effluent by soxhlet extraction and gas chromatography-flame ionization detector

    International Nuclear Information System (INIS)

    Nor Fairolzukry Ahmad Rasdy; Mohd Marsin Sanagi; Wan Aini Wan Ibrahim; Ahmedy Abu Naim

    2008-01-01

    A method has been developed for the determination of polycyclic aromatic hydrocarbons (PAHs) from palm oil mill effluent based on gas chromatography-flame ionization detection. Extraction of spiked PAHs (napthalene, fluorene phenanthrene, fluoranthene and pyrene) in palm oil waste was carried out by Soxhlet extraction using hexane-dichloromethane (60:40 v/v) as the solvent. Excellent separations were achieved using temperature programmed GC on Ultra-1 fused-silica capillary column (30 m x 250 μm ID), carrier gas helium at a flow rate of 1 mL/ min. (author)

  18. Stable isotope ratiometer-multiple ion detector (SIRMID) unit for quantitative and qualitative stable isotope studies by gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Klein, P.D.; Haumann, J.R.; Hachey, D.L.

    1975-01-01

    A stable isotope ratiometer-multiple ion detector (SIRMID) unit which can drive existing gas chromatograph-quadrupole or magnetic sector mass spectrometers to monitor up to six ions in turn is described. Each of the three pairs of ions can be selected for quantitation; thus three different or successive components can be analyzed in a single GC run. A background subtraction option permits the ion intensity in the absence of sample to be subtracted automatically during sample measurement. Displays of accumulated counts and isotope ratio are updated twice per second during the measurement and can be printed out at its conclusion. All six ions can be monitored in the analog mode by parallel outputs to a multipen recorder. Experience gained in the construction of this prototype indicates that SIRMID units could be commercially available for $10K, or about 1 / 3 rd to 1 / 6 th of the cost of even an inexpensive computer system. (U.S.)

  19. Shot-Noise-Limited Dual-Beam Detector for Atmospheric Trace-Gas Monitoring with Near-Infrared Diode Lasers

    Science.gov (United States)

    Durry, Georges; Pouchet, Ivan; Amarouche, Nadir; Danguy, Théodore; Megie, Gerard

    2000-10-01

    A dual-beam detector is used to measure atmospheric trace species by differential absorption spectroscopy with commercial near-infrared InGaAs laser diodes. It is implemented on the Spectrom tre Diodes Laser Accordables, a balloonborne tunable diode laser spectrometer devoted to the in situ monitoring of CH 4 and H 2 O. The dual-beam detector is made of simple analogical subtractor circuits combined with InGaAs photodiodes. The detection strategy consists in taking the balanced analogical difference between the reference and the sample signals detected at the input and the output of an open optical multipass cell to apply the full dynamic range of the measurements (16 digits) to the weak molecular absorption information. The obtained sensitivity approaches the shot-noise limit. With a 56-m optical cell, the detection limit obtained when the spectra is recorded within 8 ms is 10 4 (expressed in absorbance units). The design and performances of both a simple substractor and an upgraded feedback substractor circuit are discussed with regard to atmospheric in situ CH 4 absorption spectra measured in the 1.653- m region. Mixing ratios are obtained from the absorption spectra by application of a nonlinear least-squares fit to the full molecular line shape in conjunction with in situ P and T measurements.

  20. Development, optimization, validation and application of faster gas chromatography - flame ionization detector method for the analysis of total petroleum hydrocarbons in contaminated soils.

    Science.gov (United States)

    Zubair, Abdulrazaq; Pappoe, Michael; James, Lesley A; Hawboldt, Kelly

    2015-12-18

    This paper presents an important new approach to improving the timeliness of Total Petroleum Hydrocarbon (TPH) analysis in the soil by Gas Chromatography - Flame Ionization Detector (GC-FID) using the CCME Canada-Wide Standard reference method. The Canada-Wide Standard (CWS) method is used for the analysis of petroleum hydrocarbon compounds across Canada. However, inter-laboratory application of this method for the analysis of TPH in the soil has often shown considerable variability in the results. This could be due, in part, to the different gas chromatography (GC) conditions, other steps involved in the method, as well as the soil properties. In addition, there are differences in the interpretation of the GC results, which impacts the determination of the effectiveness of remediation at hydrocarbon-contaminated sites. In this work, multivariate experimental design approach was used to develop and validate the analytical method for a faster quantitative analysis of TPH in (contaminated) soil. A fractional factorial design (fFD) was used to screen six factors to identify the most significant factors impacting the analysis. These factors included: injection volume (μL), injection temperature (°C), oven program (°C/min), detector temperature (°C), carrier gas flow rate (mL/min) and solvent ratio (v/v hexane/dichloromethane). The most important factors (carrier gas flow rate and oven program) were then optimized using a central composite response surface design. Robustness testing and validation of model compares favourably with the experimental results with percentage difference of 2.78% for the analysis time. This research successfully reduced the method's standard analytical time from 20 to 8min with all the carbon fractions eluting. The method was successfully applied for fast TPH analysis of Bunker C oil contaminated soil. A reduced analytical time would offer many benefits including an improved laboratory reporting times, and overall improved clean up

  1. Halogenated pesticide analysis in orange juice by gas chromatography with electron capture detector (GC-ECD) with "6"3Ni nuclide

    International Nuclear Information System (INIS)

    Manhani, Kelly C.; Amaral, Priscila O.; Bustillos, José O.V.; Mendes, Cristiana de A.; Lacerda, João P.A. de; Silva, Jorge L. da; Instituto de Pesquisas Tecnológicas do Estado de São Paulo

    2017-01-01

    Brazil has been gain space in the market of orange juice in the last years. For the exportation of this product to keep growing, its quality of this product must be ensured by putting in force more strict legislations and custom barriers, in order to improve the well-being and health of the population. In this work were analyzed four orange juices brands produced in the State of São Paulo. It was quantified the acaricide known as Dicofol (2,2,2-trichloro-1,1-bis(4-chlorophenyl) ethanol) widely used to combat the Citrusleprosis virus, transmitted by mites to the citrus culture. This pesticide was chosen due to its importance in the production of orange in large scale and their indiscriminate use may pose risks to humans and of environment. The analytical technique applied was gas chromatography coupled with electron capture detector (GC-ECD) using the "6"3Ni nuclide. This beta (β) radiation source ionizes the carrier gas (N_2), generating an electron current that forms the baseline. The analites pass through the detector and capture electrons, generating the analytical signal that is proportional to the concentration of analite. The sample preparation was done by QuEChERS. The limits of detection (LOD) and quantification (LOQ) found were 0.005 and 0.025 mg kg"-"1 respectively. The applied methodology was efficient and presented excellent analytical sensitivity for the pesticide Dicofol, being that of four samples analyzed, only in one was found concentration of 0.03 mg kg"-"1, above the LOQ, however below the Maximum Residue Limit (MRL) for fruits (0.1 mg kg"-"1) established by Codex alimentarius. (author)

  2. Halogenated pesticide analysis in orange juice by gas chromatography with electron capture detector (GC-ECD) with {sup 63}Ni nuclide

    Energy Technology Data Exchange (ETDEWEB)

    Manhani, Kelly C.; Amaral, Priscila O.; Bustillos, José O.V.; Mendes, Cristiana de A.; Lacerda, João P.A. de; Silva, Jorge L. da, E-mail: ovega@ipen.br, E-mail: kmanhani@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (CQMA/IPEN-CNEN-SP), Sao Paulo, SP (Brazil). Centro de Química e Meio Ambiente; Instituto de Pesquisas Tecnológicas do Estado de São Paulo (LAQ- CQuim/IPT-SP), SP (Brazil). Lab. de Análises Químicas

    2017-11-01

    Brazil has been gain space in the market of orange juice in the last years. For the exportation of this product to keep growing, its quality of this product must be ensured by putting in force more strict legislations and custom barriers, in order to improve the well-being and health of the population. In this work were analyzed four orange juices brands produced in the State of São Paulo. It was quantified the acaricide known as Dicofol (2,2,2-trichloro-1,1-bis(4-chlorophenyl) ethanol) widely used to combat the Citrusleprosis virus, transmitted by mites to the citrus culture. This pesticide was chosen due to its importance in the production of orange in large scale and their indiscriminate use may pose risks to humans and of environment. The analytical technique applied was gas chromatography coupled with electron capture detector (GC-ECD) using the {sup 63}Ni nuclide. This beta (β) radiation source ionizes the carrier gas (N{sub 2}), generating an electron current that forms the baseline. The analites pass through the detector and capture electrons, generating the analytical signal that is proportional to the concentration of analite. The sample preparation was done by QuEChERS. The limits of detection (LOD) and quantification (LOQ) found were 0.005 and 0.025 mg kg{sup -1} respectively. The applied methodology was efficient and presented excellent analytical sensitivity for the pesticide Dicofol, being that of four samples analyzed, only in one was found concentration of 0.03 mg kg{sup -1}, above the LOQ, however below the Maximum Residue Limit (MRL) for fruits (0.1 mg kg{sup -1}) established by Codex alimentarius. (author)

  3. Test of tissue-equivalent scintillation detector for dose measurement of megavoltage beams

    International Nuclear Information System (INIS)

    Geso, M.; Ackerly, T.; Clift, M.A.

    2000-01-01

    Full text: The measurement of depth doses and profiles for a stereotactic radiotherapy beam presents special problems associated with the small beam size compared to the dosimeter's active detection area. In this work a locally fabricated organic plastic scintillator detector has been used to measure the depth dose and profile of a stereotactic radiotherapy beam. The 6MV beam is 1.25 cm diameter at isocentre, typical of small field stereotactic radiosurgery. The detector is a water/tissue equivalent plastic scintillator that is accompanied by Cerenkov subtraction detector. In this particular application, a negligible amount of Cerenkov light was detected. A photodiode and an electronic circuit is used instead of a photomultiplier for signal amplification. Comparison with data using a diode detector and a small size ionization chamber, indicate that the organic plastic scintillator detector is a valid detector for stereotactic radiosurgery dosimetry. The tissue equivalence of the organic scintillator also holds the promise of accurate dosimetry in the build up region. Depth doses measured using our plastic scintillator agree to within about 1% with those obtained using commercially available silicon diodes. Beam profiles obtained using plastic scintillator presents correct field width to within 0.35 mm, however some artifacts are visible in the profiles. These artifacts are about 5% discrepancy which has been shown not to be a significant factor in stereotactic radiotherapy dosimetry. Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine

  4. Neutrino mass hierarchy determination via atmospheric neutrinos with future detectors

    International Nuclear Information System (INIS)

    Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Mehta, Poonam; Sankar, S Uma; Shalgar, Shashank

    2008-01-01

    The issue of determining the neutrino mass hierarchy is one of the outstanding questions in neutrino physics. We consider the potential of hierarchy determination using atmospheric neutrinos as the source in three different proposed future detectors: A large Iron Calorimeter detector, a megaton Water Cerenkov detector and a large-mass Liquid Argon detector. If the mixing angle θ 13 is about 10 deg. (close to CHOOZ upper bound), the hierarchy sensitivity is essentially determined by resonant matter effects. To maximize the potential of these effects in atmospheric neutrinos, charge discrimination capability in the detector is desirable. Hence, detectors with this capability have an advantage in hierarchy determination. We compare and contrast the performance of the above three detectors in this respect. We perform a realistic analysis of the above future detectors for atmospheric neutrinos and show that it is possible to achieve a significant hierarchy sensitivity if the detector characteristics are favourable. Note: The abstract has been modified from its original form to incorporate suggestions received during the conference. The poster is being submitted in its original form.

  5. Standard test method for determining whether gas-leak-detector fluid solutions can cause stress corrosion cracking of brass alloys

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers an accelerated test method for evaluating the tendency of gas leak detection fluids (LDFs) to cause stress corrosion cracking (SCC) of brass components in compressed gas service. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.

  6. A Laboratory Experiment To Measure Henry's Law Constants of Volatile Organic Compounds with a Bubble Column and a Gas Chromatography Flame Ionization Detector (GC-FID)

    Science.gov (United States)

    Lee, Shan-Hu; Mukherjee, Souptik; Brewer, Brittany; Ryan, Raphael; Yu, Huan; Gangoda, Mahinda

    2013-01-01

    An undergraduate laboratory experiment is described to measure Henry's law constants of organic compounds using a bubble column and gas chromatography flame ionization detector (GC-FID). This experiment is designed for upper-division undergraduate laboratory courses and can be implemented in conjunction with physical chemistry, analytical…

  7. Lipids and Fatty Acids in Algae: Extraction, Fractionation into Lipid Classes, and Analysis by Gas Chromatography Coupled with Flame Ionization Detector (GC-FID).

    Science.gov (United States)

    Guihéneuf, Freddy; Schmid, Matthias; Stengel, Dagmar B

    2015-01-01

    Despite the number of biochemical studies exploring algal lipids and fatty acid biosynthesis pathways and profiles, analytical methods used by phycologists for this purpose are often diverse and incompletely described. Potential confusion and potential variability of the results between studies can therefore occur due to change of protocols for lipid extraction and fractionation, as well as fatty acid methyl esters (FAME) preparation before gas chromatography (GC) analyses. Here, we describe a step-by-step procedure for the profiling of neutral and polar lipids using techniques such as solid-liquid extraction (SLE), thin-layer chromatography (TLC), and gas chromatography coupled with flame ionization detector (GC-FID). As an example, in this protocol chapter, analyses of neutral and polar lipids from the marine microalga Pavlova lutheri (an EPA/DHA-rich haptophyte) will be outlined to describe the distribution of fatty acid residues within its major lipid classes. This method has been proven to be a reliable technique to assess changes in lipid and fatty acid profiles in several other microalgal species and seaweeds.

  8. TH-C-17A-02: New Radioluminescence Strategies Based On CRET (Cerenkov Radiation Energy Transfer) for Imaging and Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Volotskova, O; Sun, C; Pratx, G; Xing, L [Stanford University, Stanford, CA (United States)

    2014-06-15

    Purpose: Cerenkov photons are produced when charged particles, emitted from radionuclides, travel through a media with a speed greater than that of the light in the media. Cerenkov radiation is mostly in the UV/Blue region and, thus, readily absorbed by biological tissue. Cerenkov Radiation Energy Transfer (CRET) is a wavelength-shifting phenomenon from blue Cerenkov light to more penetrating red wavelengths. We demonstrate the feasibility of in-depth imaging of CRET light originating from radionuclides realized by down conversion of gold nanoclusters (AuNCs, a novel particle composed of few atoms of gold coated with serum proteins) in vivo. Methods: Bovine Serum Albumin, Human Serum Albumin and Transferrin conjugated gold nanoclusters were synthesized, characterized and examined for CRET. Three different clinically used radiotracers: 18F-FDG, 90Y and 99mTc were used. Optical spectrum (440–750 nm) was recorded by sensitive bioluminescence imaging system at physiological temperature. Dose dependence (activity range from 0.5 up to 800uCi) and concentration dependence (0.01 to 1uM) studies were carried out. The compound was also imaged in a xenograft mouse model. Results: Only β+ and β--emitting radionuclides (18F-FDG, 90Y) are capable of CRET; no signal was found in 99mTc (γ-emitter). The emission peak of CRET by AuNCs was found to be ∼700 nm and was ∼3 fold times of background. In vitro studies showed a linear dependency between luminescence intensity and dose and concentration. CRET by gold nanoclusters was observed in xenografted mice injected with 100uCi of 18F-FDG. Conclusion: The unique optical, transport and chemical properties of AuNCs (gold nanoclusters) make them ideal candidates for in-vivo imaging applications. Development of new molecular imaging probes will allow us to achieve substantially improved spatiotemporal resolution, sensitivity and specificity for tumor imaging and detection.

  9. The LDC detector concept

    Indian Academy of Sciences (India)

    foresees a TPC with around 200 points measured along a track, and read out by a system of micro-pattern gas detectors. These novel gas amplification devices promise to provide a stable, reliable readout system, which can be realized with comparatively little material in the endplate compared to a traditional wire readout.

  10. Detectors for Particle Radiation

    Science.gov (United States)

    Kleinknecht, Konrad

    1999-01-01

    This textbook provides a clear, concise and comprehensive review of the physical principles behind the devices used to detect charged particles and gamma rays, and the construction and performance of these many different types of detectors. Detectors for high-energy particles and radiation are used in many areas of science, especially particle physics and nuclear physics experiments, nuclear medicine, cosmic ray measurements, space sciences and geological exploration. This second edition includes all the latest developments in detector technology, including several new chapters covering micro-strip gas chambers, silicion strip detectors and CCDs, scintillating fibers, shower detectors using noble liquid gases, and compensating calorimeters for hadronic showers. This well-illustrated textbook contains examples from the many areas in science in which these detectors are used. It provides both a coursebook for students in physics, and a useful introduction for researchers in other fields.

  11. Nanoparticle-coated micro-optofluidic ring resonator as a detector for microscale gas chromatographic vapor analysis.

    Science.gov (United States)

    Scholten, K; Collin, W R; Fan, X; Zellers, E T

    2015-05-28

    A vapor sensor comprising a nanoparticle-coated microfabricated optofluidic ring resonator (μOFRR) is introduced. A multilayer film of polyether functionalized, thiolate-monolayer-protected gold nanoparticles (MPN) was solvent cast on the inner wall of the hollow cylindrical SiOxμOFRR resonator structure, and whispering gallery mode (WGM) resonances were generated with a 1550 nm tunable laser via an optical fiber taper. Reversible shifts in the WGM resonant wavelength upon vapor exposure were detected with a photodetector. The μOFRR chip was connected to a pair of upstream etched-Si chips containing PDMS-coated separation μcolumns and calibration curves were generated from the peak-area responses to five volatile organic compounds (VOCs). Calibration curves were linear, and the sensitivities reflected the influence of analyte volatility and analyte-MPN functional group affinity. Sorption-induced changes in film thickness apparently dominate over changes in the refractive index of the film as the determinant of responses for all VOCs. Peaks from the MPN-coated μOFRR were just 20-50% wider than those from a flame ionization detector for similar μcolumn separation conditions, reflecting the rapid response of the sensor for VOCs. The five VOCs were baseline separated in <1.67 min, with detection limits as low as 38 ng.

  12. Nanoparticle-coated micro-optofluidic ring resonator as a detector for microscale gas chromatographic vapor analysis

    Science.gov (United States)

    Scholten, K.; Collin, W. R.; Fan, X.; Zellers, E. T.

    2015-05-01

    A vapor sensor comprising a nanoparticle-coated microfabricated optofluidic ring resonator (μOFRR) is introduced. A multilayer film of polyether functionalized, thiolate-monolayer-protected gold nanoparticles (MPN) was solvent cast on the inner wall of the hollow cylindrical SiOx μOFRR resonator structure, and whispering gallery mode (WGM) resonances were generated with a 1550 nm tunable laser via an optical fiber taper. Reversible shifts in the WGM resonant wavelength upon vapor exposure were detected with a photodetector. The μOFRR chip was connected to a pair of upstream etched-Si chips containing PDMS-coated separation μcolumns and calibration curves were generated from the peak-area responses to five volatile organic compounds (VOCs). Calibration curves were linear, and the sensitivities reflected the influence of analyte volatility and analyte-MPN functional group affinity. Sorption-induced changes in film thickness apparently dominate over changes in the refractive index of the film as the determinant of responses for all VOCs. Peaks from the MPN-coated μOFRR were just 20-50% wider than those from a flame ionization detector for similar μcolumn separation conditions, reflecting the rapid response of the sensor for VOCs. The five VOCs were baseline separated in <1.67 min, with detection limits as low as 38 ng.

  13. Nuclear radiation detectors

    International Nuclear Information System (INIS)

    Kapoor, S.S.; Ramamurthy, V.S.

    1986-01-01

    The present monograph is intended to treat the commonly used detectors in the field of nuclear physics covering important developments of the recent years. After a general introduction, a brief account of interaction of radiation with matter relevant to the processes in radiation detection is given in Chapter II. In addition to the ionization chamber, proportional counters and Geiger Mueller counters, several gas-filled detectors of advanced design such as those recently developed for heavy ion physics and other types of studies have been covered in Chapter III. Semiconductor detectors are dealt with in Chapter IV. The scintillation detectors which function by sensing the photons emitted by the luminescence process during the interaction of the impinging radiation with the scintillation detector medium are described in Chapter V. The topic of neutron detectors is covered in Chapter VI, as in this case the emphasis is more on the method of neutron detection rather than on detector type. Electronic instrumentation related to signal pulse processing dealt with in Chapter VII. The track etch detectors based on the visualization of the track of the impinging charge particle have also been briefly covered in the last chapter. The scope of this monograph is confined to detectors commonly used in low and medium energy nuclear physics research and applications of nuclear techniques. The monograph is intended for post-graduate students and those beginning to work with the radiation detectors. (author)

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    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

  15. Ionization detector

    International Nuclear Information System (INIS)

    Steele, D.S.

    1987-01-01

    An ionization detector having an array of detectors has, for example, grounding pads positioned in the spaces between some detectors (data detectors) and other detectors (reference detectors). The grounding pads are kept at zero electric potential, i.e. grounded. The grounding serves to drain away electrons and thereby prevent an unwanted accumulation of charge in the spaces, and cause the electric field lines to be more perpendicular to the detectors in regions near the grounding pads. Alternatively, no empty space is provided there being additional, grounded, detectors provided between the data and reference detectors. (author)

  16. Development of a monitor system for gas based detectors and measurement of electron attachment in the chamber gas; Aufbau eines Monitorsystems fuer gasbasierte Detektoren und Messung der Elektronenanlagerung im Kammergas

    Energy Technology Data Exchange (ETDEWEB)

    Linzmaier, Diana

    2009-01-15

    In the framework of an international collaboration a new electron-positron linear accelerator (ILC) with a c. m. energy up to 500 GeV is planned. For the International Large Detector Concept (ILD) a time projection chamber (TPC) shall perform precise measurements of the particle tracks. In order to fulfil the high requirements on the resolution, a microstructure gas-amplification system is used for read-out. For research and development of the detector principle for the application at the ILC at DESY a large TPC prototype is developed. For the operation of the detector it is necessary to monitor its state and especially that of the measurement gas. For this purpose in the framework of this thesis a slow control system is built, which shall make possible for the different collaboration partners to operate the prototype and to integrate the slow control data into their measurement. For this with an object-oriented control system a graphic user interface was created, which makes an overview over the applied measurement devices and a driving allows. Furthermore the influence of impurities of the gas mixture by oxygen was studied. For this with a small TPC prototype measurements of the electron attachment coefficient at different oxygen concentrations were performed with a magnetic flux density of 4 T. From the amplitude of the measurement signal a rate for the electron attachment could be determined. The values obtained for this agree sufficiently in comparison with literature values. [German] Im Rahmen einer internationalen Kollaboration ist ein neuer Elektronen-Positronen-Linearbeschleuniger (ILC) mit einer Schwerpunktsenergie bis zu 500 GeV geplant. Fuer das International Large Detector Concept (ILD) soll eine Zeitprojektionskammer (TPC) praezise Vermessungen der Teilchenspuren durchfuehren. Um die hohen Anforderungen an die Aufloesung zu erfuellen, wird ein Mikrostruktur-Gasverstaerkungssystem zur Auslese verwendet. Zur Erforschung und Entwicklung des

  17. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France)

    1998-04-01

    The reports presents the main results obtained in the fields of radiation detectors and associated electronics. In the domain of X-ray gas detectors for the keV range efforts were undertaken to rise the detector efficiency. Multiple gap parallel plate chambers of different types as well as different types of X {yields} e{sup -} converters were tested to improve the efficiency (values of 2.4% at 60 KeV were reached). In the field of scintillators a study of new crystals has been carried out (among which Lutetium orthosilicate). CdTe diode strips for obtaining X-ray imaging were studied. The complete study of a linear array of 8 CdTe pixels has been performed and certified. The results are encouraging and point to this method as a satisfying solution. Also, a large dimension programmable chamber was used to study the influence of temperature on the inorganic scintillators in an interval from -40 deg. C to +150 deg. C. Temperature effects on other detectors and electronic circuits were also investigated. In the report mentioned is also the work carried out for the realization of the DEMON neutron multidetector. For neutron halo experiments different large area Si detectors associated with solid and gas position detectors were realized. In the frame of a contract with COGEMA a systematic study of Li doped glasses was undertaken aiming at replacing with a neutron probe the {sup 3}He counters presently utilized in pollution monitoring. An industrial prototype has been realised. Other studies were related to integrated analog chains, materials for Cherenkov detectors, scintillation probes for experiments on fundamental processes, gas position sensitive detectors, etc. In the field of associated electronics there are mentioned the works related to the multidetector INDRA, data acquisition, software gamma spectrometry, automatic gas pressure regulation in detectors, etc

  18. Reactor antineutrino detector iDREAM.

    Science.gov (United States)

    Gromov, M. B.; Lukyanchenko, G. A.; Novikova, G. J.; Obinyakov, B. A.; Oralbaev, A. Y.; Skorokhvatov, M. D.; Sukhotin, S. V.; Chepurnov, A. S.; Etenko, A. V.

    2017-09-01

    Industrial Detector for Reactor Antineutrino Monitoring (iDREAM) is a compact (≈ 3.5m 2) industrial electron antineutrino spectrometer. It is dedicated for remote monitoring of PWR reactor operational modes by neutrino method in real-time. Measurements of antineutrino flux from PWR allow to estimate a fuel mixture in active zone and to check the status of the reactor campaign for non-proliferation purposes. LAB-based gadolinium doped scintillator is exploited as a target. Multizone architecture of the detector with gamma-catcher surrounding fiducial volume and plastic muon veto above and below ensure high efficiency of IBD detection and background suppression. DAQ is based on Flash ADC with PSD discrimination algorithms while digital trigger is programmable and flexible due to FPGA. The prototype detector was started up in 2014. Preliminary works on registration Cerenkov radiation produced by cosmic muons were established with distilled water inside the detector in order to test electronic and slow control systems. Also in parallel a long-term measurements with different scintillator samples were conducted.

  19. Two-dimensional microstrip detector for neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Oed, A [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Because of their robust design, gas microstrip detectors, which were developed at ILL, can be assembled relatively quickly, provided the prefabricated components are available. At the beginning of 1996, orders were received for the construction of three two-dimensional neutron detectors. These detectors have been completed. The detectors are outlined below. (author). 2 refs.

  20. Silicon detectors

    International Nuclear Information System (INIS)

    Klanner, R.

    1984-08-01

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  1. Search for Primordial Black Holes with the Whipple Atmospheric Cerenkov Telescope

    Science.gov (United States)

    Linton, Eric

    2005-04-01

    Stephen Hawking's prediction that black holes should radiate like black bodies has several important consequences, including the possibility for the detection of small (˜10^15 g) black holes created in the very early universe. The detection of such primordial black holes (PBHs) would not only validate Hawking's theory, but would provide useful insights into the history of the early universe. A search through 5.5 years of archival data from the Whipple Atmospheric Cerenkov Telescope was made for TeV gamma-ray bursts on 1 s, 3 s, and 5 s timescales. Based on a null result, an upper-limit on the evaporation rate of PBHs of 2.69 x10^6 pc-3 yr^- 1 (99% CL) was made, assuming the Standard Model of particle physics. When combined with the results of an earlier search through Whipple data, this limit was lowered to 1.33 x10^6 pc-3 yr-1, which is nearly a factor of 2 better than the previous limit at this energy range.

  2. A mm-Wave, Table Top Cerenkov Free-Electron Laser

    CERN Document Server

    De la Fuente, Isabel; Van der Slot, Peter

    2004-01-01

    We have designed and constructed a compact (0.5 x 1.5 m), 100 kV Cerenkov FEL operating at a frequency of 50 GHz. The electron beam is produced by a gridded thermionic electron gun with a beam current of 800 mA. Simulations shows that 800 mA is sufficient to produce an output power of ~ 1 kW peak at 50 GHz using a total cavity reflectivity of about 10 to 20 %. The average power approaches 1 kW when the electron pulse length is extended to CW. A depressed collector will be used to increase the overall efficiency of this device. Special attention has been given to the outcoupler that has to combine multiple functions. First it has to separate the radiation field from the electron beam. Second it has to be transparent for the electron beam and acts as a partial reflector for radiation. Finally it has to convert the generated TM01 mode in the interaction region into the fundamental TE01 mode of the standard rectangular output port. We will present the overall design and experimental set-up, first experimental res...

  3. Enhancement and wavelength-shifted emission of Cerenkov luminescence using multifunctional microspheres

    International Nuclear Information System (INIS)

    Li, Joanne; Dobrucki, Lawrence W; Marjanovic, Marina; Chaney, Eric J; Suslick, Kenneth S; Boppart, Stephen A

    2015-01-01

    Cerenkov luminescence (CL) imaging is a new molecular imaging modality that utilizes the photons emitted during radioactive decay when charged particles travel faster than the phase velocity of light in a dielectric medium. Here we present a novel agent to convert and increase CL emission at longer wavelengths using multimodal protein microspheres (MSs). The 64 Cu-labeled protein microspheres contain quantum dots (QDs) encapsulated within a high-refractive-index-oil core. Dark box imaging of the MSs was conducted to demonstrate the improvement in CL emission at longer wavelengths. To illustrate the versatile design of these MSs and the potential of CL in disease diagnosis, these MSs were utilized for in vitro cell targeting and ex vivo CL-excited QD fluorescence (CL-FL) imaging of atherosclerotic plaques in rats. It was shown that by utilizing both QDs and MSs with a high-refractive-index-oil core, the CL emission increases by four-fold at longer wavelengths. Furthermore, we demonstrate that these MSs generate both an in vivo and ex vivo contrast signal. The design concept of utilizing QDs and high-index core MSs may contribute to future developments of in vivo CL imaging. (paper)

  4. Rapid analysis of cyclamate in foods and beverages by gas chromatography-electron capture detector (GC-ECD).

    Science.gov (United States)

    Yu, Shengbing; Zhu, Binghui; Lv, Fen; Li, Shaoxiao; Huang, Weixiong

    2012-10-15

    A rapid method for determination of sodium cyclamate in foods and beverages was developed. Sodium cyclamate was converted to N,N-dichloridecyclohexylamine by reaction with sodium hypochlorite under acid condition. N,N-dichloridecyclohexylamine was subsequently extracted by n-hexane and determined by gas chromatography. Conditions such as derivatization time, the concentration of sodium hypochlorite and sulphuric acid were optimised. Amino acids, aliphatic amines, and food additives such as preservatives, dyes and sweeteners showed no interference for quantification of cyclamate. The correlation coefficient of calibration curve was 0.9993 in the range of 5.0-250mg/L. The limits of detection (LOD) and limits of quantification (LOQ) were calculated as three or ten times the signal-to-noise ratio (S/N), respectively. The LOD and LOQ for yellow wine and fruit juice were 0.05 and 0.2mg/L, respectively. The LOD and LOQ for cake and preserved fruit were 0.25 and 0.8mg/kg, respectively. The intra-day and inter-day RSD were 0.28% and 1.1% (n=5), respectively. The method was successfully applied for determination of cyclamate in yellow wine, cake, fruit juice and preserved fruit. This method was simple, fast, and sensitive. It was suitable for the determination of cyclamate in foods and beverages for safety and quality control inspections. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Smoke detectors

    International Nuclear Information System (INIS)

    Bryant, J.

    1979-01-01

    An ionization smoke detector consisting of two electrodes defining an ionization chamber permitting entry of smoke, a radioactive source to ionize gas in the chamber and a potential difference applied across the first and second electrodes to cause an ion current to flow is described. The current is affected by entry of smoke. An auxiliary electrode is positioned in the ionization chamber between the first and second electrodes, and it is arranged to maintain or create a potential difference between the first electrode and the auxiliary electrode. The auxiliary electrode may be used for testing or for adjustment of sensitivity. A collector electrode divides the chamber into two regions with the auxiliary electrode in the outer sensing region. (U.K.)

  6. Application of solid-phase micro extraction for the determination of pesticides in vegetable samples by gas chromatography with an electron capture detector

    International Nuclear Information System (INIS)

    Chai, Mee Kin; Tan, Guan Huat; Kumari, Asha

    2008-01-01

    A solid-phase micro extraction (SPME) method has been developed for the determination of 9 pesticides in 2 vegetables -cucumber and tomato - samples, based on direct immersion mode and subsequent desorption into the injection port of a gas chromatograph with an electron capture detector (GC-ECD). The main factors affecting the SPME process such as extraction time and temperature, desorption time and temperature, the effect of salt addition and fiber depth into the liner were studied and optimized. The analytical procedure proposed consisted of a 30 minute ultrasonic extraction of the target compounds from 1.0 g vegetable samples with 5 mL of distilled water. Then, the samples were filtered and topped up with distilled water to 10 mL. The analytes in this aqueous extract were extracted for 15 minutes with a 100 μm thickness polydimethylsiloxane SPME fiber. Relative standard deviations for triplicate analyses of samples were less than 10 %. The recoveries of the pesticides studied in cucumber and tomato ranged from 52 % to 82 % and the RSD were below 10 %. Therefore, the proposed method is applicable in the analysis of pesticides in vegetable matrices. SPME has been shown to be a simple extraction technique, which has a number of advantages such as solvent free extraction, simplicity and compatibility with the chromatographic analytical system. (author)

  7. Validation of QuEChERS based method for determination of fenitrothion residues in tomatoes by gas chromatography-flame photometric detector: Decline pattern and risk assessment.

    Science.gov (United States)

    Malhat, Farag; Boulangé, Julien; Abdelraheem, Ehab; Abd Allah, Osama; Abd El-Hamid, Rania; Abd El-Salam, Shokr

    2017-08-15

    A simple and rapid gas chromatography with flame photometric detector (GC-FPD) determination method was developed to detect residue levels and investigate the dissipation pattern and safe use of fenitrothion in tomatoes. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) using an ethyl acetate-based extraction, followed by a dispersive solid-phase extraction (d-SPE) with primary-secondary amine (PSA) and graphite carbon black (GCB) for clean up, was applied prior to GC-FPD analysis. The method showed satisfactory linearity, recovery and precision. The limits of detection (LOD) and quantification (LOQ) were 0.005 and 0.01mg/kg, respectively. The residue levels of fenitrothion were best described by first order kinetics with a half-life of 2.2days in tomatoes. The potential health risks posed by fenitrothion were not significant, based on supervised residue trial data. The current findings could provide guidance for safe and reasonable use of fenitrothion in tomatoes and prevent health problems to consumers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Determination of acetanilide herbicides in cereal crops using accelerated solvent extraction, solid-phase extraction and gas chromatography-electron capture detector.

    Science.gov (United States)

    Zhang, Yaping; Yang, Jun; Shi, Ronghua; Su, Qingde; Yao, Li; Li, Panpan

    2011-07-01

    A method was developed to determine eight acetanilide herbicides from cereal crops based on accelerated solvent extraction (ASE) and solid-phase extraction (SPE) followed by gas chromatography-electron capture detector (GC-ECD) analysis. During the ASE process, the effect of four parameters (temperature, static time, static cycles and solvent) on the extraction efficiency was considered and compared with shake-flask extraction method. After extraction with ASE, four SPE tubes (graphitic carbon black/primary secondary amine (GCB/PSA), GCB, Florisil and alumina-N) were assayed for comparison to obtain the best clean-up efficiency. The results show that GCB/PSA cartridge gave the best recoveries and cleanest chromatograms. The analytical process was validated by the analysis of spiked blank samples. Performance characteristics such as linearity, limit of detection (LOD), limit of quantitation (LOQ), precision and recovery were studied. At 0.05 mg/kg spiked level, recoveries and precision values for rice, wheat and maize were 82.3-115.8 and 1.1-13.6%, respectively. For all the herbicides, LOD and LOQ ranged from 0.8 to 1.7 μg/kg and from 2.4 to 5.3 μg/kg, respectively. The proposed analytical methodology was applied for the analysis of the targets in samples; only three herbicides, propyzamid, metolachlor and diflufenican, were detected in two samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Ethanol concentration in 56 refillable electronic cigarettes liquid formulations determined by headspace gas chromatography with flame ionization detector (HS-GC-FID).

    Science.gov (United States)

    Poklis, Justin L; Wolf, Carl E; Peace, Michelle R

    2017-10-01

    Personal battery-powered vaporizers or electronic cigarettes were developed as an alternative to traditional cigarettes. The modern electronic cigarettes were patented in 2004 by Hon Lik in China. In May 2016, the US Food and Drug Administration (FDA) imposed regulatory statutes on e-cigarettes and their liquid formulations (e-liquids); prior to that, they were unregulated. E-liquids are typically composed of propylene glycol and/or glycerin, flavouring component(s), and active ingredient(s), such as nicotine. Fifty-six commercially available e-liquids, purchased from various sources, contained a variety of flavours and active ingredients. A headspace gas chromatography with flame ionization detector (HS-GC-FID) method was used to analyze these e-liquids for volatiles content. Only one of the e-liquids listed ethanol as a component. The chromatographic separation of volatiles was performed on a Restek BAC-1 column. A linear calibration was generated for ethanol with limits of detection and quantification (LOD/LOQ) of 0.05 mg/mL. Ethanol concentrations in the 56 e-liquids ranged from none detected to 206 mg/mL. The ethanol determined in these products may have been used in flavourants or a solvent; the reason for inclusion cannot be fully ascertained. The implications of vaporizing ethanol as an e-liquid component are unknown. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Gossipo-3 A prototype of a Front-End Pixel Chip for Read-Out of Micro-Pattern Gas Detectors

    CERN Document Server

    Brezina, Christpoh; van der Graaf, Haryy; Gromov, Vladimir; Kluit, Ruud; Kruth, Andre; Zappon, Francesco

    2009-01-01

    In a joint effort of Nikhef (Amsterdam) and the University of Bonn, the Gossipo-3 integrated circuit (IC) has been developed. This circuit is a prototype of a chip dedicated for read-out of various types of position sensitive Micro-Pattern Gas detectors (MPGD). The Gossipo-3 is defined as a set of building blocks to be used in a future highly granulated (60 μm) chip. The pixel circuit can operate in two modes. In Time mode every readout pixel measures the hit arrival time and the charge deposit. For this purpose it has been equipped with a high resolution TDC (1.7 ns) covering dynamic range up to 102 μs. Charge collected by the pixel will be measured using Time-over- Threshold method in the range from 400 e- to 28000 e- with accuracy of 200 e- (standard deviation). In Counting mode every pixel operates as a 24-bit counter, counting the number of incoming hits. The circuit is also optimized to operate at low power consumption (100 mW/cm2) that is required to avoid the need for massive power transport and coo...

  11. Introduction to detectors

    CERN Document Server

    Walenta, Albert H

    1995-01-01

    Concepts for momentum measurements,particle identification and energy measurements (calorimeters) as well for imaging applications in medecine, biology and industry (non destructive testing) will be put into relation to the specific detection princip In particular the resolution for position, time, energy and intensity measurement and the efficiency will be discussed. Signal extraction,electronic signal processing and principles of information capture will close the logic circle to the input : the radiation properties.The lecture will provide some sources for data tables and small demonstration computer programs f The basic detector physics as interaction of radiation with matter, information transport via free charges,photons and phonons and the signal formation will be presented in some depth with emphasis on the influence on specific parameters for detector The lecture will cover the most popular detector principles, gas detectors (ion chambers,MPWC's and MSGC's), semiconductor detectors scintillators and ...

  12. Optical fiber detectors as in-vivo dosimetry method of quality assurance in radiation therapy

    International Nuclear Information System (INIS)

    Plazas, M.C.; Justus, B.L.; Falkenstein, P.; Huston, A.L.; Ning, H.; Miller, R.

    2004-01-01

    A new in-vivo dosimetry system has been under development for some time using radio luminescent phosphors. These phosphors are activated, metal ion doped glasses (Ex: Cu 1± doped quartz fiber), have excellent optical transparency and offer several potential advantages for radiation dosimetry; including: small size, high sensitivity, linearity of dose response insensitivity to electromagnetic interference. The utility of these phosphors as a detection modality has been limited in real-time dosimetry applications due to the production of Cerenkov radiation in the carrier fiber, which produces a contaminant signal proportional to dose rate as well as the size of the radiation field. One possible method for eliminating this signal is using an electronic gating signal from the accelerator to delay data acquisition during the actual beam pulse, when Cerenkov radiation is produced. Due to the intrinsic properties of our particular scintillator, this method offers the best mechanism for eliminating Cerenkov noise, while retaining the ability to detect individual beam pulses. The dosimeter was tested using an external beam radiotherapy machine that provided pulses of 6 MeV x-rays. Gated detection was used to discriminate the signal collected during the radiation pulses, which included contributions from Cerenkov radiation and native fiber fluorescence, from the signal collected between the radiation pulses, which contained only the long-lived phosphorescence from the Cu 1± doped fused quartz detector. Gated detection of the phosphorescence provided accurate, real-time dose measurements that were linear with absorbed dose, independent of dose rate and that were accurate for all field sizes studied. (author)

  13. Ionization detectors, ch. 3

    International Nuclear Information System (INIS)

    Sevcik, J.

    1976-01-01

    Most measuring devices used in gas chromatography consist of detectors that measure the ionization current. The process is based on the collision of a moving high-energy particle with a target particle that is ionised while an electron is freed. The discussion of the conditions of the collision reaction, the properties of the colliding particles, and the intensity of the applied field point to a unified classification of ionisation detectors. Radioactive sources suitable for use in these detectors are surveyed. The slow-down mechanism, recombination and background current effect are discussed

  14. The Micro Wire Detector

    Energy Technology Data Exchange (ETDEWEB)

    Adeva, B.; Gomez, F.; Pazos, A.; Pfau, R.; Plo, M. E-mail: maximo.plo@cern.ch; Rodriguez, J.M.; Vazquez, P.; Labbe, J.C

    1999-10-11

    We present the performance of a new proportional gas detector. Its geometry consists of a cathode plane with 70x70 {mu}m{sup 2} apertures, crossed by 25 {mu}m anode strips to which it is attached by 50 {mu}m kapton spacers. In the region where the avalanche takes place, the anode strips are suspended in the gas mixture as in a standard wire chamber. This detector exhibits high rate capability and large gains, introducing very little material. (author)

  15. Neutron detector development at Brookhaven

    International Nuclear Information System (INIS)

    Yu, B.; Harder, J.A.; Mead, J.A.; Radeka, V.; Schaknowski, N.A.; Smith, G.C.

    2003-01-01

    Two-dimensional thermal neutron detectors have been the subject of research and development at Brookhaven for over 20 years. Based primarily on multi-wire chambers filled with a gas mixture containing 3 He, these detectors have been used in wide-ranging studies of molecular biology and material science samples. At each phase of development, experimenters have sought improvements in key parameters such as position resolution, counting rate, efficiency, solid-angle coverage and stability. A suite of detectors has been developed with sensitive areas ranging from 5x5 to 50x50 cm 2 . These devices incorporate low-noise-position readout and the best position resolution for thermal neutron gas detectors. Recent developments include a 1.5 mx20 cm detector containing multiple segments with continuously sensitive readout, and detectors with unity gain for ultra-high rate capability and long-term stability

  16. Investigation of the profile of phenolic compounds in the leaves and stems of Pandiaka heudelotii using gas chromatography coupled with flame ionization detector.

    Science.gov (United States)

    Ifeanacho, Mercy O; Ikewuchi, Catherine C; Ikewuchi, Jude C

    2017-05-01

    The profile of phenolic compounds in the leaves and stems of Pandiaka heudelotii was investigated using gas chromatography coupled with flame ionization detector. The leaves and stems had high flavonoids and benzoic acid derivatives content, and moderate levels of lignans and hydroxycinnamates. Twenty-eight known flavonoids were detected, which consisted mainly of kaempferol (41.93% in leaves and 47.97% in stems), (+)-catechin (17.12% in leaves and 16.11% in stems), quercetin (13.83% in leaves and 9.39% in stems), luteolin (7.34% in leaves and 7.71% in stems), and artemetin (6.53% in leaves and 4.83% in stems). Of the six known hydroxycinnamates detected, chlorogenic acid (80.79% in leaves and 87.56% in stems) and caffeic acid (18.98% in leaves and 12.30% in stems) were the most abundant, while arctigenin (77.81% in leaves and 83.40% in stems) and retusin (13.82% in leaves and 10.59% in stems) were the most abundant of the nine known lignans detected. Twelve known benzoic acid derivatives were detected, consisting mainly of ellagic acid (65.44% in leaves and 72.89% in stems), p-hydroxybenzoic acid (25.10% in leaves and 18.95% in stems), and vanillic acid (8.80% in leaves and 7.30% in stems). The rich phytochemical profile of the leaves and stems is an indication of their ability to serve as sources of nutraceuticals.

  17. Determination of organophosphorus flame retardants in fish by pressurized liquid extraction using aqueous solutions and solid-phase microextraction coupled with gas chromatography-flame photometric detector.

    Science.gov (United States)

    Gao, Zhanqi; Deng, Yuehua; Yuan, Wenting; He, Huan; Yang, Shaogui; Sun, Cheng

    2014-10-31

    A novel method was developed for the determination of organophosphorus flame retardants (PFRs) in fish. The method consists of a combination of pressurized liquid extraction (PLE) using aqueous solutions and solid-phase microextraction (SPME), followed by gas chromatography-flame photometric detector (GC-FPD). The experimental parameters that influenced extraction efficiency were systematically evaluated. The optimal responses were observed by extracting 1g of fish meat with the solution of water:acetonitrile (90:10, v/v) at 150°C for 5min and acid-washed silica gel used as lipid sorbent. The obtained extract was then analyzed by SPME coupled with GC-FPD without any additional clean-up steps. Under the optimal conditions, the proposed procedure showed a wide linear range (0.90-5000ngg(-1)) obtained by analyzing the spiked fish samples with increasing concentrations of PFRs and correlation coefficient (R) ranged from 0.9900 to 0.9992. The detection limits (S/N=3) were in the range of 0.010-0.208ngg(-1) with standard deviations (RSDs) ranging from 2.0% to 9.0%. The intra-day and inter-day variations were less than 9.0% and 7.8%, respectively. The proposed method was successfully applied to the determination of PFRs in real fish samples with recoveries varying from 79.8% to 107.3%. The results demonstrate that the proposed method is highly effective for analyzing PFRs in fish samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Quantitative analysis of fragrance in selectable one dimensional or two dimensional gas chromatography-mass spectrometry with simultaneous detection of multiple detectors in single injection.

    Science.gov (United States)

    Tan, Hui Peng; Wan, Tow Shi; Min, Christina Liew Shu; Osborne, Murray; Ng, Khim Hui

    2014-03-14

    A selectable one-dimensional ((1)D) or two-dimensional ((2)D) gas chromatography-mass spectrometry (GC-MS) system coupled with flame ionization detector (FID) and olfactory detection port (ODP) was employed in this study to analyze perfume oil and fragrance in shower gel. A split/splitless (SSL) injector and a programmable temperature vaporization (PTV) injector are connected via a 2-way splitter of capillary flow technology (CFT) in this selectable (1)D/(2)D GC-MS/FID/ODP system to facilitate liquid sample injections and thermal desorption (TD) for stir bar sorptive extraction (SBSE) technique, respectively. The dual-linked injectors set-up enable the use of two different injector ports (one at a time) in single sequence run without having to relocate the (1)D capillary column from one inlet to another. Target analytes were separated in (1)D GC-MS/FID/ODP and followed by further separation of co-elution mixture from (1)D in (2)D GC-MS/FID/ODP in single injection without any instrumental reconfiguration. A (1)D/(2)D quantitative analysis method was developed and validated for its repeatability - tR; calculated linear retention indices (LRI); response ratio in both MS and FID signal, limit of detection (LOD), limit of quantitation (LOQ), as well as linearity over a concentration range. The method was successfully applied in quantitative analysis of perfume solution at different concentration level (RSD≤0.01%, n=5) and shower gel spiked with perfume at different dosages (RSD≤0.04%, n=5) with good recovery (96-103% for SSL injection; 94-107% for stir bar sorptive extraction-thermal desorption (SBSE-TD). Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Comparison of analysis techniques by liquid scintillation and Cerenkov Effect for {sup 40}K quantification in aqueous samples; Comparacion de las tecnicas de analisis por centelleo liquido y efecto Cerenkov para la cuantificacion {sup 40}K en muestras acuosas

    Energy Technology Data Exchange (ETDEWEB)

    Miranda C, L.; Davila R, J. I.; Lopez del R, H.; Mireles G, F., E-mail: lilimica20@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-09-15

    In this work the counting by liquid scintillation and Cerenkov Effect to quantify {sup 40}K in aqueous samples was used. The performance of both techniques was studied by comparing the response of three commercial liquid scintillation OptiPhase HiSafe 3, Ultima Gold Ab and OptiPhase TriSafe, the vial type and presentation conditions of the sample for counting. In liquid scintillation, the ability to form homogeneous mixtures depended on the ionic strength of the aqueous solutions. The scintillator OptiPhase HiSafe 3 showed a greater charge capacity for solutions with high ionic strength (<3.4), while the scintillator OptiSafe TriSafe no form homogeneous mixtures for solutions of ionic strength higher than 0.3. Counting efficiencies for different proportions of sample and scintillator near 100% for the scintillators OptiSafe HiSafe 3 and Ultima Gold Ab were obtained. In the counting by Cerenkov Effect, the efficiency and sensitivity depended of the vial type; polyethylene vials were more suitable for counting that the glass vials. The sample volume had not significant effect on counting efficiency, obtaining an average value of 44.8% for polyethylene vials and 37.3% for glass vials. Therefore, the liquid scintillation was more efficient and sensitive for the measurement of {sup 40}K in aqueous solutions. (Author)

  20. Transmutation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Viererbl, L., E-mail: vie@ujv.c [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Lahodova, Z. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Klupak, V. [Nuclear Research Institute Rez plc (Czech Republic); Sus, F. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic); Kucera, J. [Research Centre Rez Ltd. (Czech Republic); Nuclear Physics Institute, Academy of Sciences of the Czech Republic (Czech Republic); Kus, P.; Marek, M. [Research Centre Rez Ltd. (Czech Republic); Nuclear Research Institute Rez plc (Czech Republic)

    2011-03-11

    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.

  1. Transmutation detectors

    International Nuclear Information System (INIS)

    Viererbl, L.; Lahodova, Z.; Klupak, V.; Sus, F.; Kucera, J.; Kus, P.; Marek, M.

    2011-01-01

    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.

  2. Detector and System Developments for LHC Detector Upgrades

    CERN Document Server

    Mandelli, Beatrice; Guida, Roberto; Rohne, Ole; Stapnes, Steinar

    2015-05-12

    The future Large Hadron Collider (LHC) Physics program and the consequent improvement of the LHC accelerator performance set important challenges to all detector systems. This PhD thesis delineates the studies and strategies adopted to improve two different types of detectors: the replacement of precision trackers with ever increasingly performing silicon detectors, and the improvement of large gaseous detector systems by optimizing their gas mixtures and operation modes. Within the LHC tracker upgrade programs, the ATLAS Insertable B-layer (IBL) is the first major upgrade of a silicon-pixel detector. Indeed the overall ATLAS Pixel Detector performance is expected to degrade with the increase of luminosity and the IBL will recover the performance by adding a fourth innermost layer. The IBL Detector makes use of new pixel and front-end electronics technologies as well as a novel thermal management approach and light support and service structures. These innovations required complex developments and Quality Ass...

  3. A high energy photon detector system in compact form

    International Nuclear Information System (INIS)

    Kato, Sadayuki; Sugano, Katsuhito; Yoshioka, Masakazu.

    1975-01-01

    The development of a high energy photon detector system in compact form for use in experiments of high energy physics is described, and the results of its characteristics calibrated using converted electron beams and a pair spectrometer are reported. This system consists of a total absorption lead glass Cerenkov counter, twenty hodoscope arrays for the vertical and the horizontal directions respectively, a lead plate for the conversion of γ-rays into electron-positron pairs, veto counters, photon hardener, and lead blocks for shieldings and collimation. The spatial resolution of the hodoscope is 15 mm for each direction, covering 301 x 301 mm 2 area. The energy resolution of the total absorption lead glass Cerenkov counter, whose volume is 30 x 30 x 30 cm 3 , is typically 18 % (FWHM) for the incident electron energy of 500 MeV, and it can be expressed with a relation of ΔE/E = 3.94 Esup(-1/2). (E in MeV). (auth.)

  4. Calculation of the decay rate of tachyonic neutrinos against charged-lepton-pair and neutrino-pair Cerenkov radiation

    Science.gov (United States)

    Jentschura, Ulrich D.; Nándori, István; Ehrlich, Robert

    2017-10-01

    We consider in detail the calculation of the decay rate of high-energy superluminal neutrinos against (charged) lepton pair Cerenkov radiation, and neutrino pair Cerenkov radiation, i.e., against the decay channels ν \\to ν {e}+ {e}- and ν \\to ν \\overline{ν } ν . Under the hypothesis of a tachyonic nature of neutrinos, these decay channels put constraints on the lifetime of high-energy neutrinos for terrestrial experiments as well as on cosmic scales. For the oncoming neutrino, we use the Lorentz-covariant tachyonic relation {E}ν =\\sqrt{{p}2-{m}ν 2}, where m ν is the tachyonic mass parameter. We derive both threshold conditions as well as on decay and energy loss rates, using the plane-wave fundamental bispinor solutions of the tachyonic Dirac equation. Various intricacies of rest frame versus lab frame calculations are highlighted. The results are compared to the observations of high-energy IceCube neutrinos of cosmological origin.

  5. Comparison of analysis techniques by liquid scintillation and Cerenkov Effect for 40K quantification in aqueous samples

    International Nuclear Information System (INIS)

    Miranda C, L.; Davila R, J. I.; Lopez del R, H.; Mireles G, F.

    2015-09-01

    In this work the counting by liquid scintillation and Cerenkov Effect to quantify 40 K in aqueous samples was used. The performance of both techniques was studied by comparing the response of three commercial liquid scintillation OptiPhase HiSafe 3, Ultima Gold Ab and OptiPhase TriSafe, the vial type and presentation conditions of the sample for counting. In liquid scintillation, the ability to form homogeneous mixtures depended on the ionic strength of the aqueous solutions. The scintillator OptiPhase HiSafe 3 showed a greater charge capacity for solutions with high ionic strength (<3.4), while the scintillator OptiSafe TriSafe no form homogeneous mixtures for solutions of ionic strength higher than 0.3. Counting efficiencies for different proportions of sample and scintillator near 100% for the scintillators OptiSafe HiSafe 3 and Ultima Gold Ab were obtained. In the counting by Cerenkov Effect, the efficiency and sensitivity depended of the vial type; polyethylene vials were more suitable for counting that the glass vials. The sample volume had not significant effect on counting efficiency, obtaining an average value of 44.8% for polyethylene vials and 37.3% for glass vials. Therefore, the liquid scintillation was more efficient and sensitive for the measurement of 40 K in aqueous solutions. (Author)

  6. Enhancement of Cerenkov luminescence imaging by dual excitation of Er(3+,Yb(3+-doped rare-earth microparticles.

    Directory of Open Access Journals (Sweden)

    Xiaowei Ma

    Full Text Available Cerenkov luminescence imaging (CLI has been successfully utilized in various fields of preclinical studies; however, CLI is challenging due to its weak luminescent intensity and insufficient penetration capability. Here, we report the design and synthesis of a type of rare-earth microparticles (REMPs, which can be dually excited by Cerenkov luminescence (CL resulting from the decay of radionuclides to enhance CLI in terms of intensity and penetration.Yb(3+- and Er(3+- codoped hexagonal NaYF4 hollow microtubes were synthesized via a hydrothermal route. The phase, morphology, and emission spectrum were confirmed for these REMPs by power X-ray diffraction (XRD, scanning electron microscopy (SEM, and spectrophotometry, respectively. A commercial CCD camera equipped with a series of optical filters was employed to quantify the intensity and spectrum of CLI from radionuclides. The enhancement of penetration was investigated by imaging studies of nylon phantoms and nude mouse pseudotumor models.the REMPs could be dually excited by CL at the wavelengths of 520 and 980 nm, and the emission peaks overlaid at 660 nm. This strategy approximately doubled the overall detectable intensity of CLI and extended its maximum penetration in nylon phantoms from 5 to 15 mm. The penetration study in living animals yielded similar results.this study demonstrated that CL can dually excite REMPs and that the overlaid emissions in the range of 660 nm could significantly enhance the penetration and intensity of CL. The proposed enhanced CLI strategy may have promising applications in the future.

  7. Rapid determination of strontium-90 in environmental samples by single Cerenkov counting using two different colour quench curves

    Energy Technology Data Exchange (ETDEWEB)

    Torres, J.M.; Garcia, J.F.; Llaurado, M.; Rauret, G. [Barcelona Univ. (Spain). Dept. de Quimica Analitica

    1996-11-01

    The validation of the Cerenkov radiation measurement of {sup 90}Y to determine the activity concentration of {sup 90}Sr in environmental samples is described. Liquid-liquid extraction with di-2-ethyhexylphosphoric acid in toluene was used to separate {sup 90}Y from {sup 90}Sr. Optimum conditions for Cerenkov counting (low-level counting option, counting windows, mass of solution to be measured) were established. The need for a counting efficiency correction by using a colour quench curve is stated to be essential, otherwise a significant error may occur. Two different colour quench curves (counting efficiency versus the channel ratio or spectral index parameter) were used and the results were compared. The method was applied to 12 environmental matrices: sea-water, algae, carobs, milk, almonds, hake, honey, shellfish, lamb meat, sardine, pork meat and shore sand. No significant differences were observed on using either of the two colour quench curves for any of these environmental matrices. In order to validate the proposed method, a certified soil reference material (CRM IAEA-375) was used, together with participation in an interlaboratory exercise to determine {sup 90}Sr in a natural water sample. Again, efficiency correction was performed by using either of the two colour quench curves and in both instances the calculated {sup 90}Sr activity concentration was in good agreement with the known values. (Author).

  8. The atmosphere as particle detector

    Science.gov (United States)

    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.

  9. filled neutron detectors

    Indian Academy of Sciences (India)

    Boron trifluoride (BF3) proportional counters are used as detectors for thermal neutrons. They are characterized by high neutron sensitivity and good gamma discriminating properties. Most practical BF3 counters are filled with pure boron trifluoride gas enriched up to 96% 10B. But BF3 is not an ideal proportional counter ...

  10. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  11. Detector trends

    International Nuclear Information System (INIS)

    Charpak, G.

    1986-01-01

    The author describes briefly the development of detectors for high energy physics experiments. Especially considered are semiconductor microstrip detectors, drift tubes, holographic bubble chambers, scintillating fiber optics, and calorimeters. (HSI).

  12. A conduction-cooled, 680-mm-long warm bore, 3-T Nb3Sn solenoid for a Cerenkov free electron laser

    NARCIS (Netherlands)

    Wessel, Wilhelm A.J.; den Ouden, A.; Krooshoop, Hendrikus J.G.; ten Kate, Herman H.J.; Wieland, J.; van der Slot, Petrus J.M.

    1999-01-01

    A compact, cryocooler cooled Nb3Sn superconducting magnet system for a Cerenkov free electron laser has been designed, fabricated and tested. The magnet is positioned directly behind the electron gun of the laser system. The solenoidal field compresses and guides a tube-shaped 100 A, 500 kV electron

  13. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  14. Detection of hard {beta} radiation in water using the Cerenkov effect; Detection des {beta} durs dans l'eau par effet Cerenkov

    Energy Technology Data Exchange (ETDEWEB)

    Turck, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-01-01

    The light emitted from a liquid during the passage of a particle of sufficiently high energy can be used to determine the contamination of water by {beta}-emitters. The detector based on this principle requires no special treatment of the water. Particular attention has been paid to the optical yield of the detector. However the excellent sensitivity to which this principle leads can only be attained if the background noise is considerably reduced. The electronics associated with detector make it possible to detect a contamination of 8 x 10{sup -8} {mu}c/cm{sup 3} of strontium-90 in water in about ten minutes. The apparatus presents the double advantage of having a high sensitivity and of being easy to use. Its characteristics make it possible for it to be used for the continuous control of water. (author) [French] La lumiere emise au sein d'un liquide au passage d'une particule suffisamment energetique peut permettre de determiner la contamination d'une eau en emetteurs {beta}. Le detecteur realise sur ce principe ne necessite aucun traitement special de l'eau. Un soin tout particulier a ete apporte a l'etude du rendement optique du detecteur. Cependant l'excellente sensibilite attachee au principe ne peut etre utilisee que si l'on reduit considerablement le bruit de fond. L'electronique associee au detecteur permet de reperer l'existence d'une contamination de 8 x 10{sup -8} {mu}c/cm{sup 3} de strontium-90 dans l'eau en un temps d'une dizaine de minutes. L'appareil presente l'avantage d'allier une grande sensibilite a la facilite d'emploi. Ses performances autorisent son utilisation au controle continu des eaux. (auteur)

  15. The solenoidal detector collaboration silicon detector system

    International Nuclear Information System (INIS)

    Ziock, H.J.; Gamble, M.T.; Miller, W.O.; Palounek, A.P.T.; Thompson, T.C.

    1992-01-01

    Silicon tracking systems (STS) will be fundamental components of the tracking systems for both planned major SSC experiments. The STS is physically a small part of the central tracking system and the calorimeter of the detector being proposed by the Solenoidal Detector Collaboration (SDC). Despite its seemingly small size, it occupies a volume of more than 5 meters in length and 1 meter in diameter and is an order of magnitude larger than any silicon detector system previously built. The STS will consist of silicon microstrip detectors and possibly silicon pixel detectors. The other two components are an outer barrel tracker, which will consist of straw tubes or scintillating fibers; and an outer intermediate angle tracker, which will consist of gas microstrips. The components are designed to work as an integrated system. Each componenet has specific strengths, but is individually incapable of providing the overall performance required by the physics goals of the SSC. The large particle fluxes, the short times between beam crossing, the high channel count, and the required very high position measurement accuracy pose challenging problems that must be solved. Furthermore, to avoid degrading the measurements, the solutions must be achieved using only a minimal amount of material. An additional constraint is that only low-Z materials are allowed. If that were not difficlut enough, the solutions must also be affordable

  16. Study of the physical processes involved in the operating mode of the micro-strips gas detector Micromegas; Analyse des phenomenes physiques lies au fonctionnement du detecteur gazeux a micropistes micromegas

    Energy Technology Data Exchange (ETDEWEB)

    Barouch, G

    2001-04-01

    Micromegas is a micro-strip gaseous detector invented in 1996. It consists of two volumes of gas separated by a micro-mesh. The first volume of gas, 3 mm thick, is used to liberate ionization electrons from the incident charged particle. In the second volume, only 100 {mu}m thick, an avalanche phenomenon amplifies the electrons produced in the first volume. Strips printed on an insulating substrate collect the electrons from the avalanche. The geometrical configuration of Micromegas showed many advantages. The short anode-cathode distance combined with a high granularity provide high rate capabilities due to a fast collection of ions produced during the avalanche development. Moreover, the possibility to localize the avalanche with strips printed about every hundreds of micrometers allows to measure the position of the incident particle with a good resolution. In this work, experimental tests of Micromegas are presented along with detailed Monte Carlo simulations used to understand and optimize the detector's performances. The prototypes were tested several times at the PS accelerator at CERN. The analysis of the date showed a stable and efficient behavior of Micromegas combined with an excellent space resolution. In fact, spatial resolutions of less than 15 {mu}m were obtained. In parallel with the in-beam tests, several simulations have been developed in order to gain a better understanding of the detector's response. (author)

  17. In matrix derivatization of trichloroethylene metabolites in human plasma with methyl chloroformate and their determination by solid-phase microextraction-gas chromatography-electron capture detector.

    Science.gov (United States)

    Mudiam, Mohana Krishna Reddy; Jain, Rajeev; Varshney, Meenu; Ch, Ratnasekhar; Chauhan, Abhishek; Goyal, Sudhir Kumar; Khan, Haider A; Murthy, R C

    2013-04-15

    Trichloroethylene (TCE) is a common industrial chemical that has been widely used as metal degreaser and for many industrial purposes. In humans, TCE is metabolized into dichloroacetic acid (DCA), trichloroacetic acid (TCA) and trichloroethanol (TCOH). A simple and rapid method has been developed for the quantitative determination of TCE metabolites. The procedure involves the in situ derivatization of TCE metabolites with methyl chloroformate (MCF) directly in diluted plasma samples followed by extraction and analysis with solid-phase microextraction (SPME) coupled to gas chromatography-electron capture detector (GC-ECD). Factors which can influence the efficiency of derivatization such as amount of MCF and pyridine (PYR), ratio of water/methanol were optimized. The factors which can affect the extraction efficiencies of SPME were screened using 2(7-4) Placket-Burman Design (PBD). A central composite design (CCD) was then applied to further optimize the most significant factors for optimum SPME extraction. The optimum factors for the SPME extraction were found to be 562.5mg of NaCl, pH at 1 and an extraction time of 22 min. Recoveries and detection limits of all three analytes in plasma were found to be in the range of 92.69-97.55% and 0.036-0.068 μg mL(-1) of plasma, respectively. The correlation coefficients were found to be in the range of 0.990-0.995. The intra- and inter-day precisions for TCE metabolites were found to be in the range of 2.37-4.81% and 5.13-7.61%, respectively. The major advantage of this method is that MCF derivatization allows conversion of TCE metabolites into their methyl esters in very short time (≤30 s) at room temperature directly in the plasma samples, thus makes it a solventless analysis. The method developed was successfully applied to the plasma samples of humans exposed to TCE. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Performance of New and Upgraded Detectors for Luminosity and Beam Condition Measurement at CMS

    CERN Document Server

    Leonard, Jessica Lynn

    2015-01-01

    The beam monitoring and luminosity systems of the CMS experiment are enhanced by several new and upgraded sub-detectors to match the challenges of the LHC operation and physics program at increased energy and higher luminosity. A dedicated pixelated luminosity telescope is installed for a fast and precise luminosity measurement. This detector measures coincidences between several three-layer telescopes of silicon pixel detectors to arrive at luminosity for each colliding LHC bunch pair. An upgraded fast beam conditions monitor measures the particle flux using single crystalline diamond sensors. It is equipped with a dedicated front-end ASIC produced in 130 nm CMOS technology. The excellent time resolution is used to separate collision products from machine induced background, thus serving as online luminosity measurement. A new beam-halo monitor at larger radius exploits Cerenkov light from fused silica to provide direction sensitivity and excellent time resolution to separate incoming and outgoing particles....

  19. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1992-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups: Classical semiconductor diode detectors and semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported

  20. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1995-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups; (i) classical semiconductor diode detectors and (ii) semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported. copyright 1995 American Institute of Physics

  1. DUMAND: The Ocean as a Neutrino Detector

    Energy Technology Data Exchange (ETDEWEB)

    Blood, H.; Learned, J.; Reines, F.; Roberts, A.

    1976-06-01

    We consider the possibility of using the ocean as a neutrino detector; neutrino-produced interactions result in charged particles that generate Cerenkov 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.

  2. The DELPHI Detector (DEtector with Lepton Photon and Hadron Identification)

    CERN Multimedia

    Crawley, B; Munich, K; Mckay, R; Matorras, F; Joram, C; Malychev, V; Behrmann, A; Van dam, P; Drees, J K; Stocchi, A; Adam, W; Booth, P; Bilenki, M; Rosenberg, E I; Morton, G; Rames, J; Hahn, S; Cosme, G; Ventura, L; Marco, J; Tortosa martinez, P; Monge silvestri, R; Moreno, S; Phillips, H; Alekseev, G; Boudinov, E; Martinez rivero, C; Gitarskiy, L; Davenport, M; De clercq, C; Firestone, A; Myagkov, A; Belous, K; Haider, S; Hamilton, K M; Lamsa, J; Rahmani, M H; Malek, A; Hughes, G J; Peralta, L; Carroll, L; Fuster verdu, J A; Cossutti, F; Gorn, L; Yi, J I; Bertrand, D; Myatt, G; Richard, F; Shapkin, M; Hahn, F; Ferrer soria, A; Reinhardt, R; Renton, P; Sekulin, R; Timmermans, J; Baillon, P

    2002-01-01

    % DELPHI The DELPHI Detector (Detector with Lepton Photon and Hadron Identification) \\\\ \\\\DELPHI is a general purpose detector for physics at LEP on and above the Z$^0$, offering three-dimensional information on curvature and energy deposition with fine spatial granularity as well as identification of leptons and hadrons over most of the solid angle. A superconducting coil provides a 1.2~T solenoidal field of high uniformity. Tracking relies on the silicon vertex detector, the inner detector, the Time Projection Chamber (TPC), the outer detector and forward drift chambers. Electromagnetic showers are measured in the barrel with high granularity by the High Density Projection Chamber (HPC) and in the endcaps by $ 1 ^0 $~x~$ 1 ^0 $ projective towers composed of lead glass as active material and phototriode read-out. Hadron identification is provided mainly by liquid and gas Ring Imaging Counters (RICH). The instrumented magnet yoke serves for hadron calorimetry and as filter for muons, which are identified in t...

  3. New neutrino detection technology: application of massive water detectors to accelerator neutrino physics

    International Nuclear Information System (INIS)

    Sulak, L.

    1982-01-01

    In surveying the field of new detector technology, it appears that the advent of massive, inexpensive water Cerenkov detectors may have a significant impact on future neutrino physics. These detectors offer the volumes necessary to perform experiments at very low fluxes, for example with long neutrino flight paths or with rare neutrino species (e.g. upsilon/sub e/. As an illustration of the potential on the new techniques, we consider in detail an experiment dedicated to the study of the time evolution of a neutrino beam enriched with #betta# /sub e/'s. The highest fluexes f #betta# /sub e/ appear to be achieved with current beam lines at the Brookhaven AGS or the CERN PS. An array of massive, inexpensive detectors allows a configuration optimized for good sensitivity to neutrino eigenmass differences from 0.6 eV to 20 eV and mixing angles down to 15 0 (comparable to the Cabibbo angle). The #betta# /sub e/ beam is formed using k 0 /sub e/ 3 decays. A simultaneously produced #betta#sigma phi beam from K 0 /sub e/ 3 decay serves as the normalizer. Pion generated #betta#sigma phi's are suppressed to limit background. The detector consists of a series of seven water Cerenkov modules (each with 175T fiducial mass), judiciously spaced along the #betta# line to provide flight paths from 40m to 1000m. Simulation and reconstruction neutrino events in a detector similar to the one considered show sufficient resolution in angle, energy, position and event timing relative to the beam

  4. The development and performance of the EXAM detector to search for extragalactic antimatter

    International Nuclear Information System (INIS)

    Coan, T.E.

    1989-01-01

    The design and development of a practical balloon borne instrument capable of detecting heavy (Z approximately equal to -26) antimatter in the cosmic rays are described. Emphasis is placed on describing the essential physics of the EXAM (extragalactic antimatter) instrument's individual detectors that make such a detection possible. In particular, it is shown that the responses from a plastic scintillator, a Cerenkov radiation detector, dielectric track detectors, and proportional drift tube arrays can be used to uniquely determine the speed, charge magnitude, and charge sign of a cosmic ray nucleus. This novel nonmagnetic detection scheme permits the construction of a relatively light weight (approximately 2,000 kg) detector with a large collecting power (approximately 10 sq m sr). The profound cosmological and elementary particle physics implications of the detection of just a single heavy antimatter nucleus are discussed in chapter one, along with arguments that imply that such a detected antinucleus must necessarily be extragalactic in origin. Chapters two through six describe the response of EXAM's individual detectors to the passage of heavily ionizing charged particles. Chapter seven is an overview of the mechanical construction of the entire instrument. Details of the measurement of the light collection efficiency of EXAM's Cerenkov detector and primary scintillator using sea-level muons and how this will be used to assist in the flight data analysis are contained in chapter eight. This chapter also includes a description of the instrument's electronic configuration and its data acquisition system. Finally, there are two appendices summarizing some important mechanical stress calculations that were required to actually build the instrument

  5. Radiation detectors for reactors

    International Nuclear Information System (INIS)

    Balagi, V.

    2005-01-01

    Detection and measurement of radiation plays a vital role in nuclear reactors from the point of view of control and safety, personnel protection and process control applications. Various types of radiation are measured over a wide range of intensity. Consequently a variety of detectors find use in nuclear reactors. Some of these devices have been developed in Electronics Division. They include gas-filled detectors such as 10 B-lined proportional counters and chambers, fission detectors and BF 3 counters are used for the measurement of neutron flux both for reactor control and safety, process control as well as health physics instrumentation. In-core neutron flux instrumentation employs the use detectors such as miniature fission detectors and self-powered detectors. In this development effort, several indigenous materials, technologies and innovations have been employed to suit the specific requirement of nuclear reactor applications. This has particular significance in view of the fact that several new types of reactors such as P-4, PWR and AHWR critical facilities, FBTR, PFBR as well as the refurbishment of old units like CIRUS are being developed. The development work has sought to overcome some difficulties associated with the non-availability of isotopically enriched neutron-sensing materials, achieving all-welded construction etc. The present paper describes some of these innovations and performance results. (author)

  6. Detection of hard β radiation in water using the Cerenkov effect

    International Nuclear Information System (INIS)

    Turck, B.

    1965-01-01

    The light emitted from a liquid during the passage of a particle of sufficiently high energy can be used to determine the contamination of water by β-emitters. The detector based on this principle requires no special treatment of the water. Particular attention has been paid to the optical yield of the detector. However the excellent sensitivity to which this principle leads can only be attained if the background noise is considerably reduced. The electronics associated with detector make it possible to detect a contamination of 8 x 10 -8 μc/cm 3 of strontium-90 in water in about ten minutes. The apparatus presents the double advantage of having a high sensitivity and of being easy to use. Its characteristics make it possible for it to be used for the continuous control of water. (author) [fr

  7. Optical imaging as an expansion of nuclear medicine: Cerenkov-based luminescence vs fluorescence-based luminescence

    International Nuclear Information System (INIS)

    Chin, Patrick T.K.; Welling, Mick M.; Leeuwen, Fijs W.B. van; Meskers, Stefan C.J.; Valdes Olmos, Renato A.; Tanke, Hans

    2013-01-01

    Integration of optical imaging technologies can further strengthen the field of radioguided surgery. Rather than using two separate chemical entities to achieve this extension, hybrid imaging agents can be used that contain both radionuclear and optical properties. Two types of such hybrid imaging agents are available: (1) hybrid imaging agents generated by Cerenkov luminescence imaging (CLI) of β-emitters and (2) hybrid imaging agents that contain both a radioactive moiety and a fluorescent dye. One major challenge clinicians are now facing is to determine the potential value of these approaches. With this tutorial review we intend to clarify the differences between the two approaches and highlight the clinical potential of hybrid imaging during image-guided surgery applications. (orig.)

  8. Optical imaging as an expansion of nuclear medicine: Cerenkov-based luminescence vs fluorescence-based luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Patrick T.K.; Welling, Mick M.; Leeuwen, Fijs W.B. van [Leiden University Medical Center, Interventional Molecular Imaging Laboratory, Department of Radiology, P.O. Box 9600, Leiden (Netherlands); Meskers, Stefan C.J. [Eindhoven University of Technology, Molecular Materials and Nanosystems, P.O. Box 513, Eindhoven (Netherlands); Valdes Olmos, Renato A. [Leiden University Medical Center, Interventional Molecular Imaging Laboratory, Department of Radiology, P.O. Box 9600, Leiden (Netherlands); Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands); Tanke, Hans [Leiden University Medical Center, Department of Molecular Cell Biology, P.O. Box 9600, Leiden (Netherlands)

    2013-08-15

    Integration of optical imaging technologies can further strengthen the field of radioguided surgery. Rather than using two separate chemical entities to achieve this extension, hybrid imaging agents can be used that contain both radionuclear and optical properties. Two types of such hybrid imaging agents are available: (1) hybrid imaging agents generated by Cerenkov luminescence imaging (CLI) of {beta}-emitters and (2) hybrid imaging agents that contain both a radioactive moiety and a fluorescent dye. One major challenge clinicians are now facing is to determine the potential value of these approaches. With this tutorial review we intend to clarify the differences between the two approaches and highlight the clinical potential of hybrid imaging during image-guided surgery applications. (orig.)

  9. Sensitivity improvement of Cerenkov luminescence endoscope with terbium doped Gd{sub 2}O{sub 2}S nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Xin; Chen, Xueli, E-mail: xlchen@xidian.edu.cn, E-mail: jimleung@mail.xidian.edu.cn; Cao, Xu; Zhan, Yonghua; Liang, Jimin, E-mail: xlchen@xidian.edu.cn, E-mail: jimleung@mail.xidian.edu.cn [Engineering Research Center of Molecular and Neuro Imaging of the Ministry of Education and School of Life Science and Technology, Xidian University, Xi' an, Shaanxi 710071 (China); Kang, Fei; Wang, Jing [Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China); Wu, Kaichun [Department of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi' an, Shaanxi 710032 (China)

    2015-05-25

    Our previous study showed a great attenuation for the Cerenkov luminescence endoscope (CLE), resulting in relatively low detection sensitivity of radiotracers. Here, a kind of radioluminescence nanoparticles (RLNPs), terbium doped Gd{sub 2}O{sub 2}S was mixed with the radionuclide {sup 68}Ga to enhance the intensity of emitted luminescence, which finally improved the detection sensitivity of the CLE by using the radioluminescence imaging technique. With the in vitro and in vivo pseudotumor experiments, we showed that the use of RLNPs mixed with the radionuclide {sup 68}Ga enabled superior sensitivity compared with the radionuclide {sup 68}Ga only, with 50-fold improvement on detection sensitivity, which guaranteed meeting the demands of the clinical diagnosis of gastrointestinal tract tumors.

  10. Position-sensitive X-ray detectors

    International Nuclear Information System (INIS)

    Hendrix, J.

    1982-01-01

    In this review of the application of different types of position sensitive detectors to synchrotron radiation, discussion of the proportional counters based on the gas amplification principle forms a major part. Other topics reviewed are detector requirements, multiwire proportional chamber system, drift chamber type detectors, TV detectors, and recent developments, such as that based on a micro-channel plate as the amplifying element, and charge-coupled devices. (U.K.)

  11. Particlc detectors. Foundations and applications; Teilchendetektoren. Grundlagen und Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Kolanoski, Hermann; Wermes, Norbert

    2016-08-01

    The following topics are dealt with: Interaction of particles with matter, motion of charge carriers in electric and magnetic fields, signal generation by moving charges, non-electronic detectors, gas-filled detectors, semiconductor detectors, track reconstruction and momentum measurement, photodetectors, Cherenkov detectors, transition-radiation detectors, scintillation detectors, particle identification, calorimeters, detection of cosmic particles, signal processing and noise, trigger and data acquisition systems. (HSI)

  12. Three-dimensional noninvasive monitoring iodine-131 uptake in the thyroid using a modified Cerenkov luminescence tomography approach.

    Science.gov (United States)

    Hu, Zhenhua; Ma, Xiaowei; Qu, Xiaochao; Yang, Weidong; Liang, Jimin; Wang, Jing; Tian, Jie

    2012-01-01

    Cerenkov luminescence tomography (CLT) provides the three-dimensional (3D) radiopharmaceutical biodistribution in small living animals, which is vital to biomedical imaging. However, existing single-spectral and multispectral methods are not very efficient and effective at reconstructing the distribution of the radionuclide tracer. In this paper, we present a semi-quantitative Cerenkov radiation spectral characteristic-based source reconstruction method named the hybrid spectral CLT, to efficiently reconstruct the radionuclide tracer with both encouraging reconstruction results and less acquisition and image reconstruction time. We constructed the implantation mouse model implanted with a 400 µCi Na(131)I radioactive source and the physiological mouse model received an intravenous tail injection of 400 µCi radiopharmaceutical Iodine-131 (I-131) to validate the performance of the hybrid spectral CLT and compared the reconstruction results, acquisition, and image reconstruction time with that of single-spectral and multispectral CLT. Furthermore, we performed 3D noninvasive monitoring of I-131 uptake in the thyroid and quantified I-131 uptake in vivo using hybrid spectral CLT. Results showed that the reconstruction based on the hybrid spectral CLT was more accurate in localization and quantification than using single-spectral CLT, and was more efficient in the in vivo experiment compared with multispectral CLT. Additionally, 3D visualization of longitudinal observations suggested that the reconstructed energy of I-131 uptake in the thyroid increased with acquisition time and there was a robust correlation between the reconstructed energy versus the gamma ray counts of I-131 (r(2) = 0.8240). The ex vivo biodistribution experiment further confirmed the I-131 uptake in the thyroid for hybrid spectral CLT. Results indicated that hybrid spectral CLT could be potentially used for thyroid imaging to evaluate its function and monitor its treatment for thyroid cancer.

  13. SU-G-TeP3-06: Nanoparticle-Aided External Beam Radiotherapy Leveraging the Cerenkov Effect

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Z; Ngwa, W [University of Massachusetts Lowell, Lowell, MA (United States); Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School (United States); Liu, B; Sajo, E [University of Massachusetts Lowell, Lowell, MA (United States); Yasmin-Karim, S [Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School (United States)

    2016-06-15

    Purpose: This study investigates the feasibility of exploiting the Cerenkov radiation (CR) present during external beam radiotherapy (EBRT) for significant therapeutic gain, using titanium dioxide nanoparticles (titania) delivered via a new design of radiotherapy biomaterials. Methods: Recently published work has shown that CR generated by radionuclides during PET imaging could substantially enhance damage to cancer cells in the presence of 0.625 µg/g titania. We hypothesize that equal or greater damage can be achieved during EBRT. To test this hypothesis, Monte Carlo simulation was done using GEANT4 in order to get the total CR yield inside a tumor volume during EBRT compared to that of the radionuclides. We considered a novel approach where a sufficiently potent concentration of the titania was delivered directly into the tumor using radiotherapy biomaterials (e.g. fiducials) loaded with the titania. The intra-tumor distribution/diffusion of titania released from the fiducials was calculated. An in-vitro MTS assay experiment was also carried out to establish the relative non-toxicity of titania for concentrations of up to 1 µg/g. Results: For a radiotherapy biomaterial loaded with 15 µg/g of 2-nm titania, at least 0.625 µg/g could be delivered through out a tumor sub-volume of 2-cm diameter after 14 days. This concentration level could inflict substantial damage to tumor cells during EBRT. The Monte Carlo results showed the CR yield in tumor by 6 MV radiation was higher than the radionuclides and hence potentially greater damage may be obtained during EBRT. No significant cell viability change was observed for 1 µg/g titania. Conclusion: Altogether, these preliminary findings demonstrate a potential new approach that can be used to take advantage of the CR present during megavoltage EBRT to boost damage to tumor cells. The results provide significant impetus for further experimental studies towards development of nanoparticle-aided EBRT powered by the

  14. Recent advances with a hybrid micro-pattern gas detector operated in low pressure H2 and He, for AT-TPC applications

    Directory of Open Access Journals (Sweden)

    Cortesi Marco

    2018-01-01

    Full Text Available In view of a possible application as a charge-particle track readout for an Active-Target Time Projection Chamber (AT-TPC, the operational properties and performances of a hybrid Micro-Pattern Gaseous Detector (MPGD were investigated in pure low-pressure Hydrogen (H2 and Helium (He. The detector consists of a MICROMEsh GAseous Structure (MICROMEGAS coupled to a two-cascade THick Gaseous Electron Multiplier (THGEM as a pre-amplification stage. This study reports the effective gain dependence of the hybrid-MPGD at relevant pressure (in the range of 200-760 torr for different detector arrangements. The results of this work are relevant in the field of avalanche mechanism in low-pressure, low-mass noble gases, in particularly for applications of MPGD end-cap readout for active-target Time Projection Chambers (TPC in the field of nuclear physics and nuclear astrophysics.

  15. Experimental Neutrino Physics and Astrophysics with the IMB-3 Detector

    Science.gov (United States)

    Casper, David William

    1990-01-01

    Description of the universe on the smallest (elementary particle physics) and largest (cosmology) scales has become dependent on the properties of the most weakly interacting fundamental particle known, the neutrino. The IMB experiment, designed to study nucleon decay, is also the world's largest detector of neutrinos. The experiment uses 6800 tons (3300 tons fiducial) of water as both target and detecting medium. Relativistic charges particles traversing the water radiate Cerenkov light. The distinctive ring patterns are imaged by 2048 light collectors (each a photo-multiplier tube coupled with a wavelength-shifting plate) distributed over the surfaces of the tank. This dissertation describes the IMB-3 detector, a four-fold increase in sensitivity over the original apparatus. Neutrino interactions of both atmospheric and extragalactic origin were collected during a 3.4 kiloton-year exposure. A consequence of non-zero neutrino mass could be oscillation of neutrino flavor. The energies and long flight distances of atmospheric neutrinos offer a unique opportunity to explore this possibility. To study the composition of the atmospheric neutrinos, single-ring events are classified as showering or non-showering using the geometry of the Cerenkov pattern. A simulation of neutrino interactions and a model of atmospheric neutrino production are used to predict the composition of the sample. The showering/non-showering character of an event is strongly correlated with the flavor of its neutrino parent. In the lepton momentum range p mass or "dark matter" problem result in high-energy neutrino production within the Sun. A model of dark matter capture and annihilation in the Sun predicts the resulting neutrino fluxes at Earth. No evidence of the phenomenon is observed, but for canonical values of dark matter density and velocity in the solar system, greater exposure will be required to verify or exclude the expected signal.

  16. Relationship of Ambient Atmosphere and Biological Aerosol Responses from a Fielded Pyrolysis-Gas Chromatography-Ion Mobility Spectrometry Bioanalytical Detector

    National Research Council Canada - National Science Library

    Snyder, A

    2003-01-01

    .... A pyrolysis-gas chromatography-ion mobility spectrometry stand-alone bioaerosol system was interfaced to an aerosol concentrator to collect ambient background aerosols and produce bioanalytical...

  17. Detector for atomic particles and ionizing radiations

    International Nuclear Information System (INIS)

    Mallet, Georges; Ythier, Christian.

    1976-01-01

    The aim of this invention is to provide improved detectors of atomic particles and of ionising radiations, having maximum sensitivity, by virtually suppressing all absorption of the radiation scattered by the main detector, so that these detectors are particularly suitable for fitting to anti-Compton spectrometers. Reference is particularly made to detectors of the Ge(Li) type, lithium compensated germanium, which are the most used. It is however made clear that this choice is not restrictive and that this invention not only applies to all known types of detectors and particularly to scintillator detectors, for instance to detectors such as NaI (Tl), composed of a monocrystal of a thallium activated alkaline halogenide, but also to gas, ionisation chamber and luminescent chamber type detectors and in general to all the known devices that convert the energy of particles into electric signals. Owing to the fact that the walls of the enclosure containing the main detector are composed, in the part around this detector, of an auxiliary detector, the latter detects virtually all the radiations scattered by the main detector. It does so without any loss due to the absorption of these radiations (a) by the metal walls of the enclosure usually containing the main detector and (b) by the walls of the auxiliary detector casing. It results from this that the detectors of the invention enable coincidence or anti-coincidence spectrometers with a very high performance to be made [fr

  18. Ionization particle detector

    International Nuclear Information System (INIS)

    Ried, L.

    1982-01-01

    A new device is claimed for detecting particles in a gas. The invention comprises a low cost, easy to assemble, and highly accurate particle detector using a single ionization chamber to contain a reference region and a sensing region. The chamber is designed with the radioactive source near one electrode and the second electrode located at a distance less than the distance of maximum ionization from the radioactive source

  19. The CLEO RICH detector

    International Nuclear Information System (INIS)

    Artuso, M.; Ayad, R.; Bukin, K.; Efimov, A.; Boulahouache, C.; Dambasuren, E.; Kopp, S.; Li, Ji; Majumder, G.; Menaa, N.; Mountain, R.; Schuh, S.; Skwarnicki, T.; Stone, S.; Viehhauser, G.; Wang, J.C.; Coan, T.E.; Fadeyev, V.; Maravin, Y.; Volobouev, I.; Ye, J.; Anderson, S.; Kubota, Y.; Smith, A.

    2005-01-01

    We describe the design, construction and performance of a Ring Imaging Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones with a novel 'sawtooth'-shaped exit surface. Photons in the wavelength interval 135-165nm are detected using multi-wire chambers filled with a mixture of methane gas and triethylamine vapor. Excellent π/K separation is demonstrated

  20. Longitudinal development of air-shower electrons studied from the arrival time distributions of atmospheric Cerenkov light measured at 5200 m above sea level

    International Nuclear Information System (INIS)

    Inoue, N.; Kaneko, T.; Yoshii, H.

    1985-01-01

    The longitudinal development of electrons in extensive air showers before the maximum has been studied by measuring the arrival time distributions of atmospheric Cerenkov light from air showers, with primary energies in the range 6 x 10 15 to 2 x 10 17 eV, in the Chacaltaya air-shower array. These arrival time distributions are consistent with those calculated using a model of particle interactions which contain Feynman scaling in the fragmentation region, an Esup(1/2) multiplicity law in the pionisation region and a rising cross section for primary protons. Such a model also reproduces the arrival time distributions of Cerenkov light measured in the Akeno air-shower array as described in the preceding paper, which implies a very fast development before the maximum and a slow development after the maximum. (author)