Sample records for detectors radiation

  1. Thallium bromide radiation detectors

    Microsoft Academic Search

    K. S. Shah; J. C. Lund; F. Olschner; L. Moy; M. R. Squillante

    1989-01-01

    Radiation detectors have been fabricated from crystals of the semiconductor material thallium bromide (TlBr) and the performance of these detectors as room temperature photon spectrometers has been measured. These detectors exhibit improved energy resolution over previously reported TlBr detectors. These results indicate that TlBr is a very promising radiation detector material.

  2. Nuclear radiation detectors

    Microsoft Academic Search

    Luiz Alexandre Schuch; Daniel Jean Roger Nordemann

    1990-01-01

    Detectors of nuclear radiation, such as gaseous detectors, scintillators, and semiconductors, are presented through their general properties and with their operating systems. The semiconductor detectors are studied with more details.

  3. Nuclear Radiation Detectors

    Microsoft Academic Search

    G. A. Morton

    1962-01-01

    Nuclear radiation detectors are required in all the major fields of nuclear science and technology. They fall into two principal categories, single element detectors and imaging detectors. Single element detectors can be classified into four types, based upon their physical mode of operation. These are 1) Scintillation counters, 2) Gas ionization detectors, a) Ionization chambers, b) Proportional counters, c) Geiger-Mueller

  4. Silicon radiation detectors

    Microsoft Academic Search

    Pavel Rehak

    2003-01-01

    A rapid progress of past 20 years in silicon radiation detectors is reviewed. The availability of silicon as almost ideal semiconductor material is one of the main reasons for this progress. The well-defined properties of the silicon-silicon dioxide interface allowed the development of detector structures beyond the structure of a classical diode detector, which was practically the only silicon detector

  5. Tin Can Radiation Detector.

    ERIC Educational Resources Information Center

    Crull, John L.

    1986-01-01

    Provides instructions for making tin can radiation detectors from empty aluminum cans, aluminum foil, clear plastic, copper wire, silica gel, and fine, unwaxed dental floss put together with tape or glue. Also provides suggestions for activities using the detectors. (JN)

  6. Microwave Radiation Detector

    NASA Technical Reports Server (NTRS)

    Lesh, J. R.

    1984-01-01

    Direct photon detector responds to microwave frequencies. Method based on trapped-ion frequency-generation standards proposed to detect radio-frequency (RF) radiation at 40.5 GHz. Technique used for directdetection (RF) communication, radar, and radio astronomy.

  7. Amorphous silicon radiation detectors

    Microsoft Academic Search

    V. Perez-Mendez; S. N. Kaplan

    1992-01-01

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of

  8. Photovoltaic radiation detector element

    DOEpatents

    Agouridis, D.C.

    1980-12-17

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein in the edge of which closely approaches but is spaced from the current collector strips.

  9. Photovoltaic radiation detector element

    DOEpatents

    Agouridis, Dimitrios C. (Oak Ridge, TN)

    1983-01-01

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein the edge of which closely approaches but is spaced from the current collector strips.

  10. Transition radiation detectors

    Microsoft Academic Search

    Boris Dolgoshein

    1993-01-01

    The use of transition radiation (TR) as a means of identifying high energy particles has now become a subject of intensive experimental investigations and applications. Our intention is first to study the physics of these phenomena and to describe ways of building detectors which can efficiently identify particles.

  11. Semiconductor radiation detector

    DOEpatents

    Patt, Bradley E. (Sherman Oaks, CA); Iwanczyk, Jan S. (Los Angeles, CA); Tull, Carolyn R. (Orinda, CA); Vilkelis, Gintas (Westlake Village, CA)

    2002-01-01

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  12. ALICE Transition Radiation Detector

    E-print Network

    Pachmayer, Y

    2013-01-01

    The Transition Radiation Detector (TRD) is the main electron detector in ALICE. In conduction with the TPC and the ITS, it provides the necessary electron identification capability to study: - Production of light and heavy vector mesons as well as the continuum in the di-electron channel, - Semi leptonic decays of hadrons with open charm and open beauty via the single-electron channel using the displaced vertex information provided by the ITS, - Correlated DD and BB pairs via coincidences of electrons in the central barrel and muons in the forward muon arm, - Jets with high P? tracks in one single TRD stack.

  13. Radiation Hazard Detector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NASA technology has made commercially available a new, inexpensive, conveniently-carried device for protection, of people exposed to potentially dangerous levels of microwave radiation. Microwaves are radio emissions of extremely high frequency. They can be hazardous but the degree of hazard is not yet well understood. Generally, it is believed that low intensity radiation of short duration is not harmful but that exposure to high levels can induce deep internal burns, affecting the circulatory and nervous systems, and particularly the eyes. The Department of Labor's Occupational Safety and Health Administration (OSHA) has established an allowable safe threshold of exposure. However, people working near high intensity sources of microwave energy-for example, radar antennas and television transmitters-may be unknowingly exposed to radiation levels beyond the safe limit. This poses not only a personal safety problem but also a problem for employers in terms of productivity loss, workman's compensation claims and possible liability litigation. Earlier-developed monitoring devices which warn personnel of dangerous radiation levels have their shortcomings. They can be cumbersome and awkward to use while working. They also require continual visual monitoring to determine if a person is in a dangerous area of radiation, and they are relatively expensive, another deterrent to their widespread adoption. In response to the need for a cheaper and more effective warning system, Jet Propulsion Laboratory developed, under NASA auspices, a new, battery-powered Microwave Radiation Hazard Detector. To bring the product to the commercial market, California Institute Research Foundation, the patent holder, granted an exclusive license to Cicoil Corporation, Chatsworth, California, an electronic components manufacturer.

  14. Semiconductor nuclear radiation detector studies

    Microsoft Academic Search

    A. H. Sher

    1974-01-01

    In response to a problem that arose with regard to the availability of germanium for lithium-drifted germanium detectors (Ge(Li) detectors), a comprehensive program was undertaken aimed toward the development of a method for the rapid specification of germanium quality for nuclear radiation detector use, and the determination of factors affecting germanium quality. Measurements on a large number of germanium crystals,

  15. Transition Radiation Detector in MACRO

    Microsoft Academic Search

    Mario Nicola Mazziotta

    1999-01-01

    The MACRO detector is located in the Gran Sasso Laboratory. MACRO's overburden varies from to ? . A transition radiation detector (TRD) has been added to the MACRO detector in order to measure the residual energy of muons entering MACRO, i.e. the energy they have after passing through the Gran Sasso's rock overburden. The TRD consists of three identical modules

  16. Compound semiconductor radiation detectors

    NASA Astrophysics Data System (ADS)

    Owens, Alan; Peacock, A.

    2004-09-01

    We discuss the potential benefits of using compound semiconductors for the detection of X- and ?-ray radiation. While Si and Ge have become detection standards for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by one or more of their physical limitations; namely the need for ancillary cooling systems or bulky cryogenics, their modest stopping powers and radiation intolerance. Compound semiconductors encompass such a wide range of physical properties that it is technically feasible to engineer a material to any application. Wide band-gap compounds offer the ability to operate in a wide range of thermal and radiation environments, whilst still maintaining sub-keV spectral resolution at hard X-ray wavelengths. Narrow band-gap materials, on the other hand, offer the potential of exceeding the spectral resolution of both Si and Ge, by as much as a factor of 3. Assuming that the total system noise can be reduced to a level commensurate with Fano noise, spectroscopic detectors could work in the XUV, effectively bridging the gap between the ultraviolet and soft X-ray wavebands. Thus, in principle, compound semiconductor detectors can provide continuous spectroscopic coverage from the far infrared through to ?-ray wavelengths. However, while they are routinely used at infrared and optical wavelengths, in other bands, their development has been plagued by material and fabrication problems. This is particularly true at hard X- and ?-ray wavelengths, where only a few compounds (e.g., GaAs, CdZnTe and HgI2) have evolved sufficiently to produce working detection systems. In this paper, we examine the current status of research in compound semiconductors and by a careful examination of material properties and future requirements, recommend a number of compounds for further development. In the longer term, when material problems are sufficiently under control, we believe the future lies in the development of heterostructures and inserted interface layers to overcome contacting problems and quantum heterostructures and superlattices to facilitate low-noise readout.

  17. Radiation damage of germanium detectors

    NASA Technical Reports Server (NTRS)

    Pehl, R. H.

    1978-01-01

    Energetic particles can produce interstitial-vacancy pairs in a crystal by knocking the atoms from their normal positions. Detectors are unique among semiconductor devices in depending on very low concentrations of electrically active impurities, and also on efficient transport of holes and electrons over relatively large distances. Because the dense regions of damage produced by energetic particles may result in donors and/or acceptors, and also provide trapping sites for holes and electrons, detectors are very sensitive to radiation damage. In addition to these effects occurring within the detector, radiation may also change the characteristics of the exposed surfaces causing unpredictable effects on the detector leakage current. Radiation-induced surface degradation has rarely, if ever, been observed for germanium detectors. The possibility of minimizing hole trapping in charge collection by the use of a high-purity germanium coaxial detector configured with the p (+) contact on the coaxial periphery is discussed.

  18. Transition Radiation Detector in MACRO

    Microsoft Academic Search

    M. N. Mazziotta

    1999-01-01

    The MACRO detector is located in the Gran Sasso Laboratory. MACRO's\\u000aoverburden varies from 3150 to 7000 hg\\/cm^2. A transition radiation detector\\u000a(TRD) has been added to the MACRO detector in order to measure the residual\\u000aenergy of muons entering MACRO, i.e. the energy they have after passing through\\u000athe Gran Sasso's rock overburden. The TRD consists of three identical

  19. Radiation hard cryogenic silicon detectors

    Microsoft Academic Search

    L. Casagrande; M. C. Abreu; W. H. Bell; P. Berglund; W. de Boer; E. Borchi; K. Borer; M. Bruzzi; S. Buontempo; S. Chapuy; V. Cindro; P. Collins; N. D'Ambrosio; C. Da Viá; S. Devine; B. Dezillie; Z. Dimcovski; V. Eremin; A. Esposito; V. Granata; E. Grigoriev; F. Hauler; E. Heijne; S. Heising; S. Janos; L. Jungermann; I. Konorov; Z. Li; C. Lourenço; M. Mikuz; T. O. Niinikoski; V. O'Shea; S. Pagano; V. G. Palmieuri; S. Paul; S. Pirollo; K. Pretzl; P. Rato; G. Ruggiero; K. Smith; P. Sonderegger; P. Sousa; E. Verbitskaya; S. Watts; M. Zavrtanik

    2002-01-01

    It has been recently observed that heavily irradiated silicon detectors, no longer functional at room temperature, “resuscitate” when operated at temperatures below 130K. This is often referred to as the “Lazarus effect”. The results presented here show that cryogenic operation represents a new and reliable solution to the problem of radiation tolerance of silicon detectors.

  20. Picosecond photoconductors as radiation detectors

    Microsoft Academic Search

    R. S. Wagner; J. M. Bradley; R. B. Hammond

    1986-01-01

    A new class of extremely high-speed radiation detectors has been developed. They are simple and inexpensive to fabricate, rugged, and reliable. Their sensitivity to gamma-rays, X-rays, soft X-rays, charged particles, and light has been demonstrated, and response speeds of less than 100 ps have been obtained. Their current response is proportional to incident-radiation intensity. The detectors are not used for

  1. Picosecond Photoconductors as Radiation Detectors

    Microsoft Academic Search

    Ronald S. Wagner; Jeffrey M. Bradley; Robert B. Hammond

    1986-01-01

    We have developed a new class of extremely high-speed radiation detectors. They are simple and inexpensive to fabricate, rugged, and reliable. We have demonstrated their sensitivity to gamma-rays, x-rays, soft x-rays, charged particles, and light and have obtained response speeds of <100 ps. Their current response is proportional to incident-radiation intensity. The detectors are not used for detecting single particles

  2. Solid xenon radiation detectors

    NASA Astrophysics Data System (ADS)

    Dolinski, Michelle J.

    2014-03-01

    Cryogenic liquid xenon detectors have become a popular technology in the search for rare events, such as dark matter interactions and neutrinoless double beta decay. The power of the liquid xenon detector technology is in the combination of the ionization and scintillation signals, resulting in particle discrimination and improved energy resolution over the ionization-only signal. The improved energy resolution results from a unique anti-correlation phenomenon that has not been described from first principles. Solid xenon bolometers, under development at Drexel University, are expected to have excellent counting statistics in the phonon channel, with energy resolution of 0.1% or better. This additional energy channel may offer the final piece of the puzzle in understanding liquid xenon detector energy response. Supported by a grant from the Charles E. Kaufman Foundation.

  3. Gaseous Radiation Detectors

    NASA Astrophysics Data System (ADS)

    Sauli, Fabio

    2014-06-01

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

  4. Broadband optical radiation detector

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Hong, S. D.; Moacanin, J. (inventors)

    1981-01-01

    A method and apparatus for detecting optical radiation by optically monitoring temperature changes in a microvolume caused by absorption of the optical radiation to be detected is described. More specifically, a thermal lens forming material is provided which has first and second opposite, substantially parallel surfaces. A reflective coating is formed on the first surface, and a radiation absorbing coating is formed on the reflective coating. Chopped, incoming optical radiation to be detected is directed to irradiate a small portion of the radiation absorbing coating. Heat generated in this small area is conducted to the lens forming material through the reflective coating, thereby raising the temperature of a small portion of the lens forming material and causing a thermal lens to be formed therein.

  5. Cadmium telluride photovoltaic radiation detector

    DOEpatents

    Agouridis, Dimitrios C. (Oak Ridge, TN); Fox, Richard J. (Oak Ridge, TN)

    1981-01-01

    A dosimetry-type radiation detector is provided which employs a polycrystalline, chlorine-compensated cadmium telluride wafer fabricated to operate as a photovoltaic current generator used as the basic detecting element. A photovoltaic junction is formed in the wafer by painting one face of the cadmium telluride wafer with an n-type semiconductive material. The opposite face of the wafer is painted with an electrically conductive material to serve as a current collector. The detector is mounted in a hermetically sealed vacuum containment. The detector is operated in a photovoltaic mode (zero bias) while DC coupled to a symmetrical differential current amplifier having a very low input impedance. The amplifier converts the current signal generated by radiation impinging upon the barrier surface face of the wafer to a voltage which is supplied to a voltmeter calibrated to read quantitatively the level of radiation incident upon the detecting wafer.

  6. Modern detectors for radiation monitors

    Microsoft Academic Search

    A. V. Shumakov; A. S. Sviridov; S. V. Kolesnikov

    2011-01-01

    The possibilities of using modern photon and neutron detectors for developing radiation monitors, specifically, LaBr3, Bi4Ge3O12, CdWO4, LiI, ZnO, Lu2SiO5(Ce), CdTe, and HgI2, microtubes from organic scintillators, nanomaterials, and detectors based on gaseous and solid-state electronic multipliers\\u000a are examined. A comparison is made of conventional detectors based on NaI(Tl) and CsI(Tl), plastic scintillators, and 3He counters. The advantages of the

  7. Radiation detector passes big test.

    PubMed

    2011-03-01

    The new Emergency Department Notification System (EDNS) for radiation detection has been successfully tested at University of Pittsburgh Medical Center Presbyterian Hospital in Pittsburgh. Physicians in the hospital ED and radiation oncology departments agree this"new generation" device offers several benefits. Isotopes regularly used for diagnoses and therapy will not set off the detectors. Because dangerous isotopes can be detected in a patient's body, if radioactive dust has been inhaled, the detectors will set off an alarm. Machines such as CT scans can be saved from contamination. PMID:21449511

  8. Advanced Space Radiation Detector Technology Development

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    The advanced space radiation detector development team at the NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

  9. Advanced Space Radiation Detector Technology Development

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

  10. Portable Radiation Detectors

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Through a Small Business Innovation Research (SBIR) contract from Kennedy Space Center, General Pneumatics Corporation's Western Research Center satisfied a NASA need for a non-clogging Joule-Thomson cryostat to provide very low temperature cooling for various sensors. This NASA-supported cryostat development played a key part in the development of more portable high-purity geranium gamma-ray detectors. Such are necessary to discern between the radionuclides in medical, fuel, weapon, and waste materials. The outcome of the SBIR project is a cryostat that can cool gamma-ray detectors, without vibration, using compressed gas that can be stored compactly and indefinitely in a standby mode. General Pneumatics also produces custom J-T cryostats for other government, commercial and medical applications.

  11. Pyromagnetic infrared radiation detectors

    Microsoft Academic Search

    R. W. Bene; R. M. Walser

    1975-01-01

    Work on the spin reorientation transition in YbFeO3 was completed. This work showed the two second order transitions associated with the spin reorientation transition. Experimental work on 15 MHz on the family of materials (CoS(2-x)Se(x) has been completed. This study investigates the detector material limitations on high frequency response. In particular the effect of eddy currents is examined both theoretically

  12. Radiation Detector Materials: An Overview

    SciTech Connect

    Milbrath, Brian D.; Peurrung, Anthony J.; Bliss, Mary; Weber, William J.

    2008-10-10

    This review describes the current state of radiation detection material science, with particular emphasis on national security needs and the goal of identifying the challenges and opportunities that this area represents for the materials science community. Radiation detector materials physics is reviewed, which sets the stage for performance metrics that determine the relative merit of existing and new materials. Semiconductors and scintillators represent the two primary classes of radiation detector materials that are of interest. The state-of-the-art and limitations for each of these materials classes are presented, along with possible avenues of research. Novel materials that could overcome the need for single crystals will also be discussed. Finally, new methods of material discovery and development are put forward – the goal being to provide more predictive guidance and faster screening of candidate materials – and thus ultimately the faster development of superior radiation detection materials.

  13. The ALICE transition radiation detector

    Microsoft Academic Search

    Tariq Mahmoud

    2003-01-01

    The ALICE Transition Radiation Detector (TRD) is equipped with 750m2 total area of gas chambers with radiators for particle tracking and electron identification above 1GeV\\/c, divided in 540 modules organized in 18 sectors and 6 layers, in a barrel geometry between 2.9 and 3.7m from the beam axis. The TRD will also serve as a trigger on high-pte+e- pairs in

  14. Avalanche semiconductor radiation detectors

    SciTech Connect

    Sadygov, Z.Y. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation); [Azerbaijan Academy of Sciences, Baku (Azerbaijan). Physics Inst.; Zheleznykh, I.M.; Kirillova, T.A. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research] [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research; Malakhov, N.A.; Jejer, V.N. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation)

    1996-06-01

    Operation of novel avalanche semiconductor detector, produced on the basis of heterojunctions Si-SiC and Si-Si{sub x}O{sub y} is described. A uniform avalanche process with gain from 10{sup 3} to 10{sup 5} can be reached depending on the conductivity of SiC and Si{sub x}O{sub y} layers. Two types of avalanche photodetectors designed for applications in wavelength range 500--10,00 nm with quantum efficiency 60 {+-} 10% (650 nm) and 200--700 nm with quantum efficiency 60 {+-} 15% (450 nm) are presented.

  15. Ionizing Radiation Detector

    DOEpatents

    Wright, Gomez W. (Nashville, TN); James, Ralph B. (Livermore, CA); Burger, Arnold (Nashville, TN); Chinn, Douglas A. (Livermore, CA)

    2003-11-18

    A CdZnTe (CZT) crystal provided with a native CdO dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals is disclosed. A two step process is provided for forming the dielectric coating which includes etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and passivating the CZT crystal surface with a solution of 10 w/o NH.sub.4 F and 10 w/o H.sub.2 O.sub.2 in water after attaching electrical contacts to the crystal surface.

  16. Flexible composite radiation detector

    DOEpatents

    Cooke, D. Wayne (Santa Fe, NM); Bennett, Bryan L. (Los Alamos, NM); Muenchausen, Ross E. (Los Alamos, NM); Wrobleski, Debra A. (Los Alamos, NM); Orler, Edward B. (Los Alamos, NM)

    2006-12-05

    A flexible composite scintillator was prepared by mixing fast, bright, dense rare-earth doped powdered oxyorthosilicate (such as LSO:Ce, LSO:Sm, and GSO:Ce) scintillator with a polymer binder. The binder is transparent to the scintillator emission. The composite is seamless and can be made large and in a wide variety of shapes. Importantly, the composite can be tailored to emit light in a spectral region that matches the optimum response of photomultipliers (about 400 nanometers) or photodiodes (about 600 nanometers), which maximizes the overall detector efficiency.

  17. Compound semiconductor radiation detectors

    Microsoft Academic Search

    Alan Owens; A. Peacock

    2004-01-01

    We discuss the potential benefits of using compound semiconductors for the detection of X- and ?-ray radiation. While Si and Ge have become detection standards for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by one or more of their physical limitations; namely the need for ancillary cooling systems or bulky

  18. Advanced Radiation Detector Development

    SciTech Connect

    The University of Michigan

    1998-07-01

    Since our last progress report, the project at The University of Michigan has continued to concentrate on the development of gamma ray spectrometers fabricated from cadmium zinc telluride (CZT). This material is capable of providing energy resolution that is superior to that of scintillation detectors, while avoiding the necessity for cooling associated with germanium systems. In our past reports, we have described one approach (the coplanar grid electrode) that we have used to partially overcome some of the major limitations on charge collection that is found in samples of CZT. This approach largely eliminates the effect of hole motion in the formation of the output signal, and therefore leads to pulses that depend only on the motion of a single carrier (electrons). Since electrons move much more readily through CZT than do holes, much better energy resolution can be achieved under these conditions. In our past reports, we have described a 1 cm cube CZT spectrometer fitted with coplanar grids that achieved an energy resolution of 1.8% from the entire volume of the crystal. This still represents, to our knowledge, the best energy resolution ever demonstrated in a CZT detector of this size.

  19. InI nuclear radiation detectors

    Microsoft Academic Search

    M. R. Squillante; C. Zhou; J. Zhang; L. P. Moy; K. S. Shah

    1993-01-01

    Semiconductor radiation detectors are fabricated on single crystal wafers of indium iodide and tested both as direct radiation detectors and as optical detectors coupled to a scintillator crystal. The initial performance of the devices is encouraging but some chemical instability of the crystals is observed. Improvements in the detector performance may be possible by enhancing the InI crystal purity and

  20. Radiation hardness studies of CVD diamond detectors

    Microsoft Academic Search

    C. Bauer; I. Baumann; C. Colledani; J. Conway; P. Delpierre; F. Djama; W. Dulinski; A. Fallou; K. K. Gan; R. S. Gilmore; E. Grigoriev; G. Hallewell; S. Han; T. Hessing; K. Honschied; J. Hrubec; D. Husson; H. Kagan; D. Kania; R. Kass; W. Kinnison; K. T. Knöpfle; M. Krammer; T. J. Llewellyn; P. F. Manfredi; L. S. Pan; H. Pernegger; M. Pernicka; R. Plano; V. Re; S. Roe; A. Rudge; M. Schaeffer; S. Schnetzer; S. Somalwar; V. Speziali; R. Stone; R. J. Tapper; R. Tesarek; W. Trischuk; R. Turchetta; G. B. Thomson; R. Wagner; P. Weilhammer; C. White; H. Ziock; M. Zoeller

    1995-01-01

    The inherent properties of diamond make it an ideal material for tracking detectors especially in the high rate, high radiation environments of future colliders such as the LHC. In order to survive in this environment, detectors must be radiation hard. We have constructed charged particle detectors using high quality CVD diamond and performed radiation hardness tests on them. The signal

  1. A low temperature gravitational radiation detector

    NASA Technical Reports Server (NTRS)

    Hamilton, W. O.

    1971-01-01

    The beginning design of an experiment is discussed for studying gravitational radiation by using massive detectors which are cooled to ultralow temperatures in order to improve the signal to noise ratios and the effective range and stability of the detectors. The gravitational detector, a low detection system, a cooled detector, magnetic support, superconducting shielding, and superconducting accelerometer detector are described.

  2. Transition Radiation Detector in MACRO

    E-print Network

    M. N. Mazziotta; for the MACRO Collaboration

    1999-05-13

    The MACRO detector is located in the Gran Sasso Laboratory. MACRO's overburden varies from 3150 to 7000 hg/cm^2. A transition radiation detector (TRD) has been added to the MACRO detector in order to measure the residual energy of muons entering MACRO, i.e. the energy they have after passing through the Gran Sasso's rock overburden. The TRD consists of three identical modules with a total horizontal area of 36 m^2. The results presented here are referred to single and double events in MACRO with one muon crossing one of the TRD modules. Our data show that double muons are more energetic than single ones, as predicted by the interaction models of primary cosmic rays with the atmosphere.

  3. Plasma Panel Based Radiation Detectors

    SciTech Connect

    Friedman, Dr. Peter S. [Integrated Sensors, LLC; Varner Jr, Robert L [ORNL; Ball, Robert [University of Michigan; Beene, James R [ORNL; Ben Moshe, M. [Tel Aviv University; Benhammou, Yan [Tel Aviv University; Chapman, J. Wehrley [University of Michigan; Etzion, E [Tel Aviv University; Ferretti, Claudio [University of Michigan; Bentefour, E [Ion Beam Applications; Levin, Daniel S. [University of Michigan; Moshe, M. [Tel Aviv University; Silver, Yiftah [Tel Aviv University; Weaverdyck, Curtis [University of Michigan; Zhou, Bing [University of Michigan

    2013-01-01

    The plasma panel sensor (PPS) is a gaseous micropattern radiation detector under current development. It has many operational and fabrication principles common to plasma display panels (PDPs). It comprises a dense matrix of small, gas plasma discharge cells within a hermetically sealed panel. As in PDPs, it uses non-reactive, intrinsically radiation-hard materials such as glass substrates, refractory metal electrodes, and mostly inert gas mixtures. We are developing these devices primarily as thin, low-mass detectors with gas gaps from a few hundred microns to a few millimeters. The PPS is a high gain, inherently digital device with the potential for fast response times, fine position resolution (< 50 m RMS) and low cost. In this paper we report here on prototype PPS experimental results in detecting betas, protons and cosmic muons, and we extrapolate on the PPS potential for applications including detection of alphas, heavy-ions at low to medium energy, thermal neutrons and X-rays.

  4. Advanced concepts for semiconductor nuclear radiation detectors

    Microsoft Academic Search

    J. Kemmer

    1990-01-01

    By applying the technologies of semiconductor device fabrication, new types of Si radiation detectors have been developed. These include low-noise detectors for energy spectroscopy as well as detectors for precise position measurement of radiation. The activities on smart sensors resulted in detectors with on-chip low-noise signal amplification. One of the most interesting ideas is a random-access pixel detector with charge

  5. Inexpensive solid state radiation detector

    NASA Astrophysics Data System (ADS)

    Aplin, Karen; Hastings, Peter; Harrison, R. Giles; Nicoll, Keri

    2015-04-01

    Monitoring of environmental radioactivity is of interest both within the geosciences community and to groups such as the emergency services who need to quickly assess the safety of an environment. Here we present a light weight and inexpensive detector based on solid state technology, that can be easily worn or carried, or used disposably. It responds to gamma radiation and other radioactive particles such as those from space weather and cosmic rays. Unlike traditional technology such as the Geiger counter, the detector can operate at low voltage without the need for step-up circuitry, and it can also distinguish different particle energies. It is suitable for monitoring background radioactivity from cosmic rays and radon as well as responding to higher radioactivity levels. We anticipate that the device will have a broad range of end users, from terrestrial to space applications.

  6. RADIATION DETECTORS. 3. THEIR OPERATING LIMITATIONS

    Microsoft Academic Search

    Gray

    1959-01-01

    All types of detectors are limited by their response to unwanted ; radiation. Detectors chosen must be of sufficient sensitivity to provide from ; the lowest level to be measured a statistical error small enough to be within the ; limits of accuracy required. The influence of these factors on the choice of a ; detector and the limits withia

  7. Semiconductor nuclear radiation detector studies. Final report

    Microsoft Academic Search

    Sher

    1974-01-01

    In response to a problem that arose with regard to the availability of ; germanium for lithium-drifted germanium detectors (Ge(Li) detectors), a ; comprehensive program was undertaken aimed toward the development of a method for ; the rapid specification of germanium quality for nuclear radiation detector use, ; and the determination of factors affecting germanium quality. Measurements on a ;

  8. Development of CVD diamond radiation detectors

    Microsoft Academic Search

    W Adam; C Bauer; E Berdermann; F Bogani; E Borchi; Mara Bruzzi; C Colledani; J Conway; W Dabrowski; P A Delpierre; A Deneuville; W Dulinski; B van Eijk; A Fallou; D Fisch; F Foulon; M Friedl; K K Gan; E Gheeraert; E A Grigoriev; G D Hallewell; R Hall-Wilton; S Han; F G Hartjes; Josef Hrubec; D Husson; H Kagan; D R Kania; J Kaplon; R Kass; K T Knöpfle; Manfred Krammer; P F Manfredi; D Meier; M Mishina; F Le Normand; L S Pan; H Pernegger; Manfred Pernicka; S Pirollo; V Re; J L Riester; S Roe; D G Roff; A Rudge; S R Schnetzer; S Sciortino; V Speziali; H Stelzer; R Stone; R J Tapper; R J Tesarek; G B Thomson; M L Trawick; W Trischuk; R Turchetta; A M Walsh; R Wedenig; Peter Weilhammer; H J Ziock; M M Zoeller

    1998-01-01

    Diamond is a nearly ideal material for detecting ionizing radiation. Its outstanding radiation hardness, fast charge collection and low leakage current allow a diamond detector to be used in high ra diation, high temperature and in aggressive chemical media. We have constructed charged particle detectors using high quality CVD diamond. Characterization of the diamond samples and various detect ors are

  9. Properties of lead iodide semiconductor radiation detectors

    NASA Astrophysics Data System (ADS)

    Lund, J. C.; Shah, K. S.; Squillante, M. R.; Moy, L. P.; Sinclair, F.; Entine, G.

    1989-11-01

    Semiconductor radiation detectors have been fabricated from melt grown crystals of lead iodide (PbI2) and the performance of these detectors as room temperature X-ray spectrometers has been measured. These detectors exhibit good energy resolution (915 eV FWHM for the 5.9 keV peak of 55Fe at 20°C). Preliminary results indicate they are more stable than HgI2 detectors and capable of operating at temperatures over 100°C.

  10. Radiation damage effects on solid state detectors

    NASA Technical Reports Server (NTRS)

    Trainor, J. H.

    1972-01-01

    Totally depleted silicon diodes are discussed which are used as nuclear particle detectors in investigations of galactic and solar cosmic radiation and trapped radiation. A study of radiation and chemical effects on the diodes was conducted. Work on electron and proton irradiation of surface barrier detectors with thicknesses up to 1 mm was completed, and work on lithium-drifted silicon devices with thicknesses of several millimeters was begun.

  11. A novel compact real time radiation detector.

    PubMed

    Li, Shiping; Xu, Xiufeng; Cao, Hongrui; Tang, Shibiao; Ding, Baogang; Yin, Zejie

    2012-08-01

    A novel compact real time radiation detector with cost-effective, ultralow power and high sensitivity based on Geiger counter is presented. The power consumption of this detector which employs CMOS electro circuit and ultralow-power microcontroller is down to only 12.8 mW. It can identify the presences of 0.22 ?Ci (60)Co at a distance of 1.29 m. Furthermore, the detector supports both USB bus and serial interface. It can be used for personal radiation monitoring and also fits the distributed sensor network for radiation detection. PMID:22738843

  12. Development of a plasma panel radiation detector

    E-print Network

    Ball, R; Ben-Moshe, M; Benhammou, Y; Bensimon, R; Chapman, J W; Etzion, E; Ferretti, C; Friedman, P S; Levin, D S; Silver, Y; Varner, R L; Weaverdyck, C; Wetzel, R; Zhou, B; Anderson, T; McKinny, K; Bentefour, E H

    2014-01-01

    This article reports on an investigation of a radiation detector based on plasma display panel technology. The plasma panel sensor (PPS) is a variant of micropattern gas radiation detectors. PPS components are non-reactive and intrinsically radiation-hard materials, such as glass substrates, metal electrodes and inert gas mixtures. Plasma display panels used as detectors were tested with cosmic ray muons, beta rays and gamma rays, protons, and thermal neutrons. The results demonstrated risetimes and time resolution of a few nanoseconds, as well as spatial resolution compatible with the pixel pitch.

  13. Development of innovative silicon radiation detectors

    E-print Network

    Balbuena, JuanPablo

    Silicon radiation detectors fabricated at the IMB-CNM (CSIC) Clean Room facilities using the most innovative techniques in detector technology are presented in this thesis. TCAD simulation comprises an important part in this work as becomes an essential tool to achieve exhaustive performance information of modelled detectors prior their fabrication and subsequent electrical characterization. Radiation tolerance is also investigated in this work using TCAD simulations through the potential and electric field distributions, leakage current and capacitance characteristics and the response of the detectors to the pass of different particles for charge collection efficiencies. Silicon detectors investigated in this thesis were developed for specific projects but also for applications in experiments which can benefit from their improved characteristics, as described in Chapter 1. Double-sided double type columns 3D (3D-DDTC) detectors have been developed under the NEWATLASPIXEL project in the framework of the CERN ...

  14. Bubble detector characterization for space radiation.

    PubMed

    Green, A R; Andrews, H R; Bennett, L G I; Clifford, E T H; Ing, H; Jonkmans, G; Lewis, B J; Noulty, R A; Ough, E A

    2005-01-01

    In light of the importance of the neutron contribution to the dose equivalent received by space workers in the near-Earth radiation environment, there is an increasing need for a personal dosimeter that is passive in nature and able to respond to this neutron field in real time. Recent Canadian technology has led to the development of a bubble detector, which is sensitive to neutrons, but insensitive to low linear energy transfer (LET) radiation. By changing the composition of the bubble detector fluid (or "superheat"), the detectors can be fabricated to respond to different types of radiation. This paper describes a preliminary ground-based research effort to better characterize the bubble detectors of different compositions at various charged-particle accelerator facilities, which are capable of simulating the space radiation field. PMID:15835053

  15. Semiconductor High-Energy Radiation Scintillation Detector

    E-print Network

    Kastalsky, A; Spivak, B

    2006-01-01

    We propose a new scintillation-type detector in which high-energy radiation produces electron-hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible attenuation. We discuss two ways to accomplish this, one based on doping the semiconductor with shallow impurities of one polarity type, preferably donors, the other by heterostructure bandgap engineering. The proposed semiconductor scintillator combines the best properties of currently existing radiation detectors and can be used for both simple radiation monitoring, like a Geiger counter, and for high-resolution spectrography of the high-energy radiation. The most important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombi...

  16. Development of a silicon carbide radiation detector

    Microsoft Academic Search

    F. H. Ruddy; A. R. Dulloo; J. G. Seidel; S. Seshadri; L. B. Rowland

    1998-01-01

    The radiation detection properties of semiconductor detectors made of 4H silicon carbide were evaluated. Both Schottky and p-n junction devices were tested. Exposure to alpha particles from a 238Pu source led to robust signals from the detectors. The resolution of the Schottky SiC detector was 5.8% (FWHM) at an energy of 294 keV, while that of the p-n junction was

  17. Cerenkov background radiation in imaging detectors

    Microsoft Academic Search

    Edward I. Rosenblatt; Edward A. Beaver; Ross D. Cohen; J. B. Linsky; Ron W. Lyons

    1991-01-01

    The authors discuss results of an analysis of background dark data obtained with the Digicon detector in the faint object spectrograph on board the Hubble Space Telescope. Time sequenced data are presented which show the background recorded by the detector as it orbits the Earth at an altitude of 600 km. The authors propose that Cerenkov radiation produced by cosmic

  18. Characteristics of radiation detectors for diagnostic radiology

    Microsoft Academic Search

    Larry A. DeWerd; Louis K. Wagner

    1999-01-01

    The use of X-rays for diagnosis has been significant since its discovery. A measurement of the X-ray dose is the main determinant for risk vs benefit of these examinations. Radiation detectors are important for dose measurement. A description of these detectors, including the most frequently used ionization chamber, aids in the understanding necessary for their use. Proper and accurate use

  19. Ionizing radiation detector using multimode optical fibers

    Microsoft Academic Search

    J. J. Suter; J. C. Poret; M. Rosen; J. M. Rifkind

    1992-01-01

    An optical ionizing radiation detector, based on the attenuation of 850-nm light in 50\\/125-?m multimode fibers, is described. The detector is especially well suited for application on spacecraft because of its small design. The detection element consists of a section of coiled fibers that has been designed to strip higher-order optical modes. Cylindrical radiation shields with atomic numbers ranging from

  20. Superconductive tunnel structures as radiation detectors

    SciTech Connect

    Barone, A.; Gray, K.E.

    1985-08-01

    A brief review is given on various aspects of the potential of superconducting tunnel junctions as detectors for atomic and nuclear radiations. On the basis of recent results main advantages and drawbacks are indicated providing a preliminary comparison with the presently used semiconductor detectors. The basic ideas underlying the physics of the interaction of nuclear particles and other radiations with superconducting junctions are outlined. 9 refs., 1 tab.

  1. Wafer-fused semiconductor radiation detector

    DOEpatents

    Lee, Edwin Y. (Livermore, CA); James, Ralph B. (Livermore, CA)

    2002-01-01

    Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

  2. Processing circuitry for single channel radiation detector

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D. (Inventor); Delaune, Paul B. (Inventor); Turner, Kathryn M. (Inventor)

    2009-01-01

    Processing circuitry is provided for a high voltage operated radiation detector. An event detector utilizes a comparator configured to produce an event signal based on a leading edge threshold value. A preferred event detector does not produce another event signal until a trailing edge threshold value is satisfied. The event signal can be utilized for counting the number of particle hits and also for controlling data collection operation for a peak detect circuit and timer. The leading edge threshold value is programmable such that it can be reprogrammed by a remote computer. A digital high voltage control is preferably operable to monitor and adjust high voltage for the detector.

  3. NUCLEAR RADIATION DETECTOR HAVING ELECTROSTATICALLY CHARGEABLE ELEMENTS

    Microsoft Academic Search

    Shriner

    1963-01-01

    An ionizing radiation detector that is inexpensive and requires no ; outside source of electric current for recharging is described. The device is ; activated by shaking that develops electric charge of opposite polarities on the ; walls of an ionization chamber and on free-floating elements within the chamber. ; Ionizing radiation causes a proportional decrease of the electrostatic charge,

  4. Radiation tolerant semiconductor sensors for tracking detectors

    Microsoft Academic Search

    2006-01-01

    The CERN RD50 collaboration ``Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders'' is developing radiation tolerant tracking detectors for the upgrade of the Large Hadron Collider at CERN (Super-LHC). One of the main challenges arising from the target luminosity of 1035 cm-2 s-1 are the unprecedented high radiation levels. Over the anticipated 5 years lifetime of the

  5. Thallium Bromide Nuclear Radiation Detector Development

    Microsoft Academic Search

    Alexei V. Churilov; Guido Ciampi; Hadong Kim; Leonard J. Cirignano; William M. Higgins; Fred Olschner; Kanai S. Shah

    2009-01-01

    Thallium bromide (TlBr) is a dense, high-Z, wide bandgap semiconductor that has potential as an efficient, compact, room temperature nuclear radiation detector. In this paper we report on our recent progress in TlBr nuclear detector development. In particular, improvements in material purification have led to an order of magnitude increase in the mobility-lifetime product of electrons, (mutau)e, to as high

  6. Semiconductor high-energy radiation scintillation detector

    Microsoft Academic Search

    A. Kastalsky; S. Luryi; B. Spivak

    2006-01-01

    We propose a new scintillation-type detector in which high-energy radiation generates electron–hole pairs in a direct-gap semiconductor material that subsequently recombine producing infrared light to be registered by a photo-detector. The key issue is how to make the semiconductor essentially transparent to its own infrared light, so that photons generated deep inside the semiconductor could reach its surface without tangible

  7. Low-Power Multi-Aspect Space Radiation Detector System

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave; Freeman, Jon C.; Burkebile, Stephen P.

    2012-01-01

    The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of all of these detector technologies will result in an improved detector system in comparison to existing state-of-the-art (SOA) instruments for the detection and monitoring of the deep space radiation field.

  8. Metal-semiconductor, composite radiation detectors

    NASA Astrophysics Data System (ADS)

    Orvis, W. J.; Yee, J. H.; Fuess, D.

    1992-12-01

    In 1989, two researchers published a design for an increased efficiency x-ray detector. The design increased the efficiency of a semiconductor detector by interspersing layers of high-z metal within it. Semiconductors such as silicon make good, high-resolution radiation detectors, but they have low efficiency because they are low-z materials (z = 14). High-z metals, on the other hand, are good absorbers of high-energy photons. By interspersing high-z metal layers with semiconductor layers, the researchers combined the high absorption efficiency of the high-z metals with the good detection capabilities of a semiconductor. This project is an attempt to use the same design to produce a high-efficiency, room temperature gamma ray detector. By their nature, gamma rays require thicker metal layers to efficiently absorb them. These thicker layers change the behavior of the detector by reducing the resolution, compared to a solid state detector, and shifting the photopeak by a predictable amount. During the last year, the authors have procured and tested a commercial device with operating characteristics similar to those of a single layer of the composite device. They have modeled the radiation transport in a multi-layered device, to verify the initial calculations of layer thickness and composition. They have modeled the electrostatic field in different device designs to locate and remove high-field regions that can cause device breakdown. They have fabricated 14 single layer prototypes.

  9. Bismuth tri-iodide radiation detector development

    NASA Astrophysics Data System (ADS)

    Gokhale, Sasmit S.

    Bismuth tri-iodide is an attractive material for room temperature radiation detection. BiI3 demonstrates a number of properties that are apt for semiconductor radiation detection, especially gamma ray spectroscopy. The high atomic number (ZBi = 83 and ZI = 53) and the relatively high density (5.78 g/cm3) cause the material to have good photon stopping power, while the large band-gap (1.67 eV ) allows it to function as a room temperature radiation detector without any cooling mechanism. This work presents the fabrication and characterization of BiI3 radiation detectors. For the purpose of this research detectors were fabricated by cutting BiI3 crystal boules, followed by mechanical and chemical surface treatments. Detectors with various electrode geometries enabling single polarity charge sensing were fabricated. The electrical characteristics and the radiation response of the detectors were measured. The radiation response measurement was performed at room temperature using a 241Am alpha particle source and a 241Am sealed gamma-ray source. The spectral resolutions of the detectors varied from 2.09% - 6.1% for 59.5 keV gamma-rays and between 26% - 40% for 5.48 MeV alpha particles. Charge carrier properties such as the electron and hole mobility and lifetime were also estimated. The electron mobility for an ultrapure BiI 3 detector was estimated to be approximately 433 cm 2/Vs while that for antimony doped BiI3 was estimated to be around 956 cm2/Vs and the mobility-lifetime product for electrons was estimated to be around 5.44 x 10-4 cm 2/V. Detector simulation was performed using the Monte Carlo simulation code MCNP5. A Matlab script which incorporates charge carrier trapping and statistical variation was written to generate a gamma-ray spectrum from the simulated energy deposition spectra. Measured and simulated spectra were compared to extract the charge carrier mobility-lifetime products, which for electrons and holes were estimated to be 5 x 10-3 cm2/V and 1.3 x 10-4 cm2/V respectively. A traveling molten zone refining setup was built and successfully utilized to purify BiI3 powder. The commercially acquired powder had a starting impurity concentration of 200 ppm; this concentration was reduced to around 26 ppm after zone refining.

  10. BIBLIOGRAPHY ON SEMICONDUCTOR NUCLEAR RADIATION DETECTORS

    Microsoft Academic Search

    1958-01-01

    This bibliography consists of 72 references from the published ; literature on the potential uses of semiconductors as nuclear radiation detectors. ; Most references on the uses of cadmium sulfide have been omitted, except for ; recent articles, because excellent bibliographies have already been prepared. ; (auth);

  11. Nuclear Radiation Induced Noise in Infrared Detectors

    Microsoft Academic Search

    J. C. Pickel; M. D. Petroff

    1975-01-01

    A model for calculating the rate and amplitude of gamma ionization events in infrared detectors is presented. Several simplifying approximations to the actual, complex physical situation are applied in the model, thereby allowing an exact analytical formulation of the problem. Experimental measurements of nuclear-radiation induced noise pulse-height distributions and event rates are compared to predictions made using the model. Comparisons

  12. Nuclear radiation induced noise in infrared detectors

    Microsoft Academic Search

    J. C. Pickel; M. D. Petroff

    1975-01-01

    A model for calculating the rate and amplitude of gamma ionization events in infrared detectors is presented. Several simplifying approximations to the actual, complex physical situation are applied in the model, thereby allowing an exact analytical formulation of the problem. Experimental measurements of nuclear-radiation induced noise pulse-height distributions and event rates are compared to predictions made using the model. Comparisons

  13. Analytical model of the ferroelectric radiation detector

    Microsoft Academic Search

    J. T. Klopcic; D. L. Swanson

    1973-01-01

    As part of the Defense Nuclear Agency project Jl1 AAXPX231 to study the ; behavior of the ferroelectric radiation detector, an analytical model of the ; energy balance within a ferroelectric crystal has been developed. This model ; relates ionic spacing and charges to macroscopic quantities such as the ; pyroelectric and piezoelectric coefficients. Although a highly simplified model, ;

  14. Integrator Circuitry for Single Channel Radiation Detector

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D. (Inventor); Delaune, Paul B. (Inventor); Turner, Kathryn M. (Inventor)

    2008-01-01

    Input circuitry is provided for a high voltage operated radiation detector to receive pulses from the detector having a rise time in the range of from about one nanosecond to about ten nanoseconds. An integrator circuit, which utilizes current feedback, receives the incoming charge from the radiation detector and creates voltage by integrating across a small capacitor. The integrator utilizes an amplifier which closely follows the voltage across the capacitor to produce an integrator output pulse with a peak value which may be used to determine the energy which produced the pulse. The pulse width of the output is stretched to approximately 50 to 300 nanoseconds for use by subsequent circuits which may then use amplifiers with lower slew rates.

  15. Radiation detectors: Needs and prospects

    NASA Astrophysics Data System (ADS)

    Armantrout, G. A.

    Important applications for X and gamma ray spectroscopy are found in prospecting, materials characterization, environmental monitoring, the life sciences, and nuclear physics. The specific requirements vary for each application with varying degrees of emphasis on either spectrometer resolution, detection efficiency, or both. Since no one spectrometer is ideally suited to this wide range of needs, compromises are usually required. Gas and scintillation spectrometers have reached a level of maturity, and recent interest has concentrated on semiconductor spectrometers. Germanium detectors are showing continuing refinement and are the spectrometers of choice for high resolution applications. The new high Z semiconductors, such as CdTe and HgI2 show steady improvement but are limited in both resolution and size and will likely be used only in applications which require their unique properties.

  16. The Gas System for the HERMES Transition Radiation Detector

    E-print Network

    The Gas System for the HERMES Transition Radiation Detector by Douglas Michael Thiessen B: Master of Science Title of thesis: The Gas System for the HERMES Transition Radiation Detector Examining to HERMES. The transition radiation detector forms an integral component of the particle iden­ tification

  17. Alpha-beta radiation detector

    DOEpatents

    Fleming, D.M.; Simmons, K.L.; Froelich, T.J.; Carter, G.L.

    1998-08-18

    The invention is based in part on the discovery that a plastic housing that is lightweight is surprisingly efficient inasmuch as background signals from any gamma radiation are significantly reduced by using a plastic housing instead of a metal housing. A further aspect of the present invention is the profile of the housing as a bi-linear approximation to a parabola resulting in full optical response from any location on the scintillation material to the photomultiplier tube. A yet further aspect of the present invention is that the survey probe is resistant to magnetic fields. A yet further aspect of the present invention is the use of a snap-fit retaining bracket that overcomes the need for multiple screws. 16 figs.

  18. Alpha-beta radiation detector

    DOEpatents

    Fleming, Dale M. (Richland, WA); Simmons, Kevin L. (Kennewick, WA); Froelich, Thomas J. (West Richland, WA); Carter, Gregory L. (Richland, WA)

    1998-01-01

    The invention is based in part on the discovery that a plastic housing that is lightweight is surprisingly efficient inasmuch as background signals from any gamma radiation are significantly reduced by using a plastic housing instead of a metal housing. A further aspect of the present invention is the profile of the housing as a bi-linear approximation to a parabola resulting in full optical response from any location on the scintillation material to the photomultiplier tube. A yet further aspect of the present invention is that the survey probe is resistant to magnetic fields. A yet further aspect of the present invention is the use of a snap-fit retaining bracket that overcomes the need for multiple screws.

  19. Improved performance lead iodide nuclear radiation detectors

    NASA Astrophysics Data System (ADS)

    Deich, V.; Roth, M.

    1996-10-01

    Melt-grown lead iodide single crystals with an improved transport of positive charge carriers (holes) have been developed. It is shown that an energy resolution of about 3% can be obtained for gamma-radiation at 60 keV ( 241Am isotope source). Improvement of the spectrometric performance of lead iodide detectors at lower gamma-ray energies has been achieved as well due to better purification of the starting material and optimization of the etching procedure. Correlation between the detector performance and the structure of lead iodide crystals has been studied using X-ray diffraction analysis.

  20. Development of a plasma panel radiation detector

    E-print Network

    R. Ball; J. R. Beene; M. Ben-Moshe; Y. Benhammou; R. Bensimon; J. W. Chapman; E. Etzion; C. Ferretti; P. S. Friedman; D. S. Levin; Y. Silver; R. L. Varner; C. Weaverdyck; R. Wetzel; B. Zhou; T. Anderson; K. McKinny; E. H. Bentefour

    2014-06-14

    This article reports on the development and experimental results of commercial plasma display panels adapted for their potential use as micropattern gas radiation detectors. The plasma panel sensors (PPS) design an materials include glass substrates, metal electrodes and inert gas mixtures which provide a physically robust, hermetically-sealed device. Plasma display panels used as detectors were tested with cosmic ray muons, beta rays and gamma rays, protons and thermal neutrons. The results demonstrated rise times and time resolution of a few nanoseconds, as well as sub-millimeter spatial resolution compatible with the pixel pitch.

  1. Radiation experience with the CMS pixel detector

    E-print Network

    Viktor Veszpremi; for the CMS Collaboration

    2014-12-09

    The CMS pixel detector is the innermost component of the CMS tracker occupying the region around the centre of CMS, where the LHC beams are crossed, between 4.3 cm and 30 cm in radius and 46.5 cm along the beam axis. It operates in a high-occupancy and high-radiation environment created by particle collisions. Studies of radiation damage effects to the sensors were performed throughout the first running period of the LHC. Leakage current, depletion voltage, pixel readout thresholds, and hit finding efficiencies were monitored as functions of the increasing particle fluence. The methods and results of these measurements will be described together with their implications to detector operation as well as to performance parameters in offline hit reconstruction.

  2. Radiation experience with the CMS pixel detector

    NASA Astrophysics Data System (ADS)

    Veszpremi, V.

    2015-04-01

    The CMS pixel detector is the innermost component of the CMS tracker occupying the region around the centre of CMS, where the LHC beams are crossed, between 4.3 cm and 30 cm in radius and 46.5 cm along the beam axis. It operates in a high-occupancy and high-radiation environment created by particle collisions. Studies of radiation damage effects to the sensors were performed throughout the first running period of the LHC . Leakage current, depletion voltage, pixel readout thresholds, and hit finding efficiencies were monitored as functions of the increasing particle fluence. The methods and results of these measurements will be described together with their implications to detector operation as well as to performance parameters in offline hit reconstruction.

  3. Plasma panel-based radiation detectors

    E-print Network

    Peter Friedman; Robert Ball; James Beene; Yan Benhammou; Meny Ben-Moshe; Hassan Bentefour; J. W. Chapman; Erez Etzion; Claudio Ferretti; Daniel Levin; Yiftah Silver; Robert Varner; Curtis Weaverdyck; Bing Zhou

    2013-05-10

    The plasma panel sensor (PPS) is a gaseous micropattern radiation detector under current development. It has many operational and fabrication principles common to plasma display panels. It comprises a dense matrix of small, gas plasma discharge cells within a hermetically sealed panel. As in plasma display panels, it uses nonreactive, intrinsically radiation-hard materials such as glass substrates, refractory metal electrodes, and mostly inert gas mixtures. We are developing these devices primarily as thin, low-mass detectors with gas gaps from a few hundred microns to a few millimeters. The PPS is a high gain, inherently digital device with the potential for fast response times, fine position resolution (<50-mm RMS) and low cost. In this paper, we report on prototype PPS experimental results in detecting betas, protons, and cosmic muons, and we extrapolate on the PPS potential for applications including the detection of alphas, heavy ions at low-to-medium energy, thermal neutrons, and X-rays.

  4. Coherent Transition Radiation in Askaryan radio detectors

    E-print Network

    de Vries, Krijn D; van Eijndhoven, Nick; Meures, Thomas; O'Murchadha, Aongus; Scholten, Olaf

    2015-01-01

    We discuss the coherent transition radiation emitted by a macroscopic bunch of particles with a net charge traversing the boundary of two different media. The obtained expression is compared to the emission from a relativistically moving steady charge, as well the emission from a time-varying charge or current. As a first application, we discuss the transition radiation from high-energy cosmic-ray induced air showers hitting Earth's surface before the cascade has died out in the atmosphere. The induced emission gives rise to a radio signal which should be detectable in the currently operating Askaryan radio detectors built to search for the GZK neutrino flux.

  5. Improved performance lead iodide nuclear radiation detectors

    Microsoft Academic Search

    V. Deich; M. Roth

    1996-01-01

    Melt-grown lead iodide single crystals with an improved transport of positive charge carriers (holes) have been developed. It is shown that an energy resolution of about 3% can be obtained for gamma-radiation at 60 keV (241Am isotope source). Improvement of the spectrometric performance of lead iodide detectors at lower gamma-ray energies has been achieved as well due to better purification

  6. Thermal and nonequilibrium responses of superconductors for radiation detectors

    Microsoft Academic Search

    Z. M. Zhang; A. Frenkel

    1994-01-01

    This work summarizes the progress in the study of the superconductor response to optical radiation and in the development of infrared detectors. The recent advances in the design of high-Tc superconducting radiation detectors using silicon microfabrication technology are emphasized. Thermal and optical properties important for the detector performance are discussed. The mechanism of the nonequilibrium optical response and its potential

  7. GaN as a radiation hard particle detector

    Microsoft Academic Search

    J. Grant; R. Bates; W. Cunningham; A. Blue; J. Melone; F. McEwan; J. Vaitkus; E. Gaubas; V. O’Shea

    2007-01-01

    Semiconductor tracking detectors at experiments such as ATLAS and LHCb at the CERN Large Hadron Collider (LHC) will be subjected to intense levels of radiation. The proposed machine upgrade, the Super-LHC (SLHC), to 10 times the initial luminosity of the LHC will require detectors that are ultra-radiation hard. Much of the current research into finding a detector that will meet

  8. Characterization of detectors for extreme UV radiation

    NASA Astrophysics Data System (ADS)

    Scholze, F.; Klein, R.; Müller, R.

    2006-04-01

    Accurate measurements of the radiant power and other quantities are a prerequisite for the development and optimization of suitable radiation sources for extreme ultraviolet (EUV) lithography. Photodiodes are established as easy-to-operate detectors also in the EUV range. The calibrations at the Physikalisch-Technische Bundesanstalt are based on the comparison of the detector to be calibrated with the cryogenic electrical substitution radiometer as a primary detector standard using monochromatized synchrotron radiation at the soft x-ray radiometry beamline in the spectral range from 1 nm up to 25 nm. The spectral responsivity is measured with a relative uncertainty of 0.3% or better. For the dissemination of these high-accuracy calibrations, we investigated the stability and linearity of silicon n-on-p junction photodiodes under intense EUV irradiation in ultra-high vacuum. The maximum current in linear operation (1% relative saturation) depends on the size of the photon beam and ranges from about 3 mA for a 6 mm photon beam diameter to 0.2 mA for a 0.25 mm diameter spot. Diodes with diamond-like carbon or a TiSiN top layer proved to be stable up to a radiant exposure of about 100 kJ cm-2. Furthermore, examples of the calibration of spectrally and spatially resolving radiometric tools for EUV-source characterization are presented.

  9. Radiation damage measurements in room-temperature semiconductor radiation detectors

    Microsoft Academic Search

    Larry A. Franks; Bruce A. Brunett; Richard W. Olsen; David S. Walsh; Gyögy Vizkelethy; Jacob I. Trombka; Barney L. Doyle; Ralph B. James

    1999-01-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI2) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3MeV) proton fluences exhibit increased interstrip leakage after 1010 p\\/cm2 and significant bulk leakage after 1012 p\\/cm2. CZT exposed to 200MeV

  10. A new transition radiation detector for cosmic ray nuclei

    NASA Technical Reports Server (NTRS)

    Lheureux, J.; Meyer, P.; Muller, D.; Swordy, S.

    1981-01-01

    Test measurements on materials for transition radiation detectors at a low Lorentz factor are reported. The materials will be based on board Spacelab-2 for determining the composition and energy spectra of nuclear cosmic rays in the 1 TeV/nucleon range. The transition radiation detectors consist of a sandwich of radiator-photon detector combinations. The radiators emit X-rays and are composed of polyolefin fibers used with Xe filled multiwired proportional chamber (MWPC) detectors capable of detecting particle Lorentz factors of several hundred. The sizing of the detectors is outlined, noting the requirement of a thickness which provides a maximum ratio of transition radiation to total signal in the chambers. The fiber radiator-MWPC responses were tested at Fermilab and in an electron cyclotron. An increase in transition radiation detection was found as a square power law of Z, and the use of six radiator-MWPC on board the Spacelab-2 is outlined.

  11. IMPROVEMENTS IN OR RELATING TO NUCLEAR RADIATION DETECTOR SHIELDING

    Microsoft Academic Search

    1962-01-01

    A radiation detection unit is provided with castle shielding consisting ; of lid, sleeve, radiation detector tube mounting, and base sections. The ; positions of the radiation detector tube mounting and sleeve sections may be ; interchanged relative to the base. (R.J.S.)

  12. Radiation-induced damage in GaAs particle detectors

    Microsoft Academic Search

    R. L. Bates; C. Da Via; A. Pickford; C. Raine; K. M. Smith

    1997-01-01

    The motivation for investigating the use of GaAs as a material for detecting particles in experiments for high-energy physics (HEP) arose from its perceived resistance to radiation damage. This is a vital requirement for detector materials that are to be used in experiments at future accelerators where the radiation environments would exclude all but the most radiation resistant of detector

  13. Radiation detector having a multiplicity of individual detecting elements

    DOEpatents

    Whetten, Nathan R. (Burnt Hills, NY); Kelley, John E. (Albany, NY)

    1985-01-01

    A radiation detector has a plurality of detector collection element arrays immersed in a radiation-to-electron conversion medium. Each array contains a multiplicity of coplanar detector elements radially disposed with respect to one of a plurality of positions which at least one radiation source can assume. Each detector collector array is utilized only when a source is operative at the associated source position, negating the necessity for a multi-element detector to be moved with respect to an object to be examined. A novel housing provides the required containment of a high-pressure gas conversion medium.

  14. The AMS-02 transition radiation detector

    NASA Astrophysics Data System (ADS)

    Kirn, Th.; AMS-02 TRD Group

    2007-10-01

    The Alpha Magnetic Spectrometer (AMS-02) experiment will be mounted on the International Space Station (ISS) for 3 years to perform precision cosmic particle spectroscopy in space. The search for dark matter candidates requires precise e+-spectroscopy in the energy range from 10 GeV up to 300 GeV. Therefore, the dominating p-background has to be reduced by a factor of 106. This will be achieved with the AMS-02 electromagnetic calorimeter delivering 3-4 orders of magnitude and the transition radiation detector with proton rejection between 100 and 1000. The AMS-02 TRD consists of 20 layers of 6 mm diameter straw modules alternating with 20 mm layers of polyethylene/polypropylene fleece radiator. The straws are filled with a 80 %:20 %Xe/CO2 gas mixture at 1.0 bar absolute from a recirculating gas system designed to operate >3 years. The straw modules will be operated in proportional mode at a gas gain of 3000. For the readout a dedicated low-power data-acquisition system based on VA analog multiplexers has been developed. The completed construction and assembly of the detector is presented with special emphasis on space qualification, long flight duration aspects and calibration of the AMS-02 TRD. This project is funded by the German Space Agency DLR (contract 50OO0501), the US Department of Energy DOE and NASA.

  15. Radiation detector system having heat pipe based cooling

    DOEpatents

    Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul

    2006-10-31

    A radiation detector system having a heat pipe based cooling. The radiation detector system includes a radiation detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the radiation detector, whereby heat is generated by the TEC. A heat removal device dissipates the heat generated by the TEC to surrounding environment. A heat pipe has a first end thermally coupled to the TEC to receive the heat generated by the TEC, and a second end thermally coupled to the heat removal device. The heat pipe transfers the heat generated by the TEC from the first end to the second end to be removed by the heat removal device.

  16. Detection of Nuclear Radiations; DETECTORES DE RADIACIONES NUCLEARES

    Microsoft Academic Search

    Sanz

    1959-01-01

    The lectures given on radiation detection instruments are summarized. ; The detectors discussed are ionization chambers, proportional counters, Geiger ; counters, scintillation detectors, and neutron detectors. The characteristics ; which must be considered in the design of associated electronic equipment are ; emphasized. (J.S.R.);

  17. Numerical Model of Graphene-Based Radiation Detector Response

    E-print Network

    Chen, Yong P.

    of expected energy resolution and noise analysis for GRDs. I. INTRODUCTION GRAPHENE is a single atomic layerNumerical Model of Graphene-Based Radiation Detector Response Michael Foxe, Student Member, IEEE. Chen, Member, IEEE, and Igor Jovanovic Abstract--Graphene-based radiation detectors (GRDs) have

  18. Pyroelectric detector development for the Radiation Measurement system

    NASA Technical Reports Server (NTRS)

    Hubbard, G. S.; Mcmurray, Robert E., Jr.; Hanel, R. P.; Dominguez, D. E.; Valero, F. P. J.; Baumann, Hilary; Hansen, W. L.; Haller, E. E.

    1993-01-01

    A new class of high detectivity pyroelectric detectors developed for optimization of the radiation measurement system within the framework of the Atmospheric Radiation Measurement program is described. These devices are intended to provide detectivities of up to about 10 exp 11 cm Hz exp 0.5/W with cooling to about 100 K required for the detector focal plane.

  19. Space Radiation Detector with Spherical Geometry

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  20. Progress in the Development of Plasma Panel Radiation Detectors

    E-print Network

    Robert Ball; James R. Beene; Yan Benhammou; Meny Ben Moshe; J. Wehrley Chapman; Tiesheng Dai; Erez Etzion; Peter S. Friedman; Daniel S. Levin; Yiftah Silver; Guy Sherman; Robert L. Varner Jr.; Curtis Weaverdyck; Steve White; J. Yu; Bing Zhou

    2010-12-30

    Plasma Display Panels (PDP), the underlying engine of panel plasma television displays, are being investigated for their utility as radiation detectors called Plasma Panel Sensors (PPS). The PPS a novel variant of a micropattern radiation detector, is intended to be a fast, high resolution detector comprised of an array of plasma discharge cells operating in a hermetically sealed gas mixture. We report on the PPS development effort, including recent laboratory measurements.

  1. Wire chamber radiation detector with discharge control

    DOEpatents

    Perez-Mendez, Victor (Berkeley, CA); Mulera, Terrence A. (Berkeley, CA)

    1984-01-01

    A wire chamber radiation detector (11) has spaced apart parallel electrodes (16) and grids (17, 18, 19) defining an ignition region (21) in which charged particles (12) or other ionizing radiations initiate brief localized avalanche discharges (93) and defining an adjacent memory region (22) in which sustained glow discharges (94) are initiated by the primary discharges (93). Conductors (29, 32) of the grids (18, 19) at each side of the memory section (22) extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles (12) were detected by sequentially transmitting pulses to the conductors (29) of one grid (18) while detecting transmissions of the pulses to the orthogonal conductors (36) of the other grid (19) through glow discharges (94). One of the grids (19) bounding the memory region (22) is defined by an array of conductive elements (32) each of which is connected to the associated readout conductor (36) through a separate resistance (37). The wire chamber (11) avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or near simultaneous charged particles (12) have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

  2. A virtual phase CCD detector for synchrotron radiation applications

    NASA Astrophysics Data System (ADS)

    Rodricks, Brian; Clarke, Roy; Smither, Robert; Fontaine, Alain

    1989-08-01

    A two-dimensional charge coupled device (CCD) detector, based on the Texas Instruments ``virtual phase'' CCD, has been developed for synchrotron radiation applications. Simultaneous near-edge and multilayer scattering experiments have been carried out with the detector on an energy-dispersive synchrotron beamline. The detector was used in an optical mode where the CCD element is coupled to a phosphor screen by a pair of focusing and demagnifying lenses. We report on the performance of the detector in this mode.

  3. Design of SJ-10 Space Radiation Detector Prototype

    E-print Network

    Liu, Yaqing; Cui, Xingzhu; Peng, Wenxi; Fan, Ruirui; Gao, Xiaohua Liang Ming; Zhang, Yunlong; Zhang, Chengmo; Zhang, Jiayu; Yang, Jiawei; Wang, Jinzhou; Dong, Fei Zhang Yifan; Guo, Dongya; Zhou, Dawei

    2014-01-01

    The space radiation detector is a space apparatus for detecting the outer-space particles and monitoring the radiation environment. Though identifying the particles and acquiring the biological experimental data, we can learn about the space radiation impacts on the human body and defend the space radiation damage. This paper designed a prototype of the space radiation detector for SJ-10 and evaluated the performance by the system simulation. More specifically, the space radiation impacts on the human body were analyzed including the different particles, the radiation flux and the energy channels. Then the detector system based on analysis results were built by the Monte Carlo simulation. Finally, the detection algorithms of incident energy range were proposed to identify the outer-space particles and provide the reliable radiation environment data for biological experimental apparatus.

  4. SEMICONDUCTOR DETECTORS IN RADIATION MEDICINE: RADIOTHERAPY AND RELATED APPLICATIONS

    Microsoft Academic Search

    ANATOLY B. ROSENFELD; Wollongong NSW

    Semiconductor radiation detectors play an important role in radiation instrumentation. They have many advantages due to their\\u000a small size, outstanding energy resolution in nuclear spectroscopy, easy pixilation for high spatial resolution and ability\\u000a of integration with readout electronics. Advancement in microelectronic industry made silicon one of the most popular material\\u000a for radiation detectors in medicine with applications in diagnostic and

  5. The silicon transition radiation detector: Performance and perspectives

    NASA Astrophysics Data System (ADS)

    Brigida, M.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Loparco, F.; Marangelli, B.; Mazziotta, M. N.; Mirizzi, N.; Rainò, S.; Spinelli, P.

    2007-03-01

    The Silicon Transition Radiation Detector (SiTRD) consists of multiple modules each composed by a radiator and a silicon strip detector operating inside a magnetic field region. This design allows to well separate inside the detector volume the charged particle with respect to the transition radiation X-rays eventually produced in the radiator. In this paper we will show the results of a beam test performed at low momenta, up to 5 GeV/c, with a reduced scale detector prototype. We have also implemented a full Monte Carlo simulation to design a SiTRD for an accelerator a cosmic ray experiment at higher momenta, up to 100 GeV/c. We have simulated two different detector configurations and we have studied their performance.

  6. Flame detector operable in presence of proton radiation

    NASA Technical Reports Server (NTRS)

    Walker, D. J.; Turnage, J. E.; Linford, R. M. F.; Cornish, S. D. (inventors)

    1974-01-01

    A detector of ultraviolet radiation for operation in a space vehicle which orbits through high intensity radiation areas is described. Two identical ultraviolet sensor tubes are mounted within a shield which limits to acceptable levels the amount of proton radiation reaching the sensor tubes. The shield has an opening which permits ultraviolet radiation to reach one of the sensing tubes. The shield keeps ultraviolet radiation from reaching the other sensor tube, designated the reference tube. The circuitry of the detector subtracts the output of the reference tube from the output of the sensing tube, and any portion of the output of the sensing tube which is due to proton radiation is offset by the output of the reference tube. A delay circuit in the detector prevents false alarms by keeping statistical variations in the proton radiation sensed by the two sensor tubes from developing an output signal.

  7. Radiation Effect On Gas Electron Multiplier Detector Performance

    SciTech Connect

    Park, Kwang June [Korean Atomic Energy Research Institute, Daejeon, 305-600 (Korea, Republic of); Baldeloma, Edwin; Park, Seongtae; White, Andrew P.; Yu, Jaehoon [Department of Physics, University of Texas at Arlington, Arlington TX 76019 (United States)

    2011-06-01

    Gas Electron Multiplier (GEM) detector is a gas device with high gain and high efficiency. These detectors use chemically perforated 65 {mu}m thick copper clad Kapton polyimide foils. Given its potential for detecting X-rays and other radiations, GEM detectors may be used in an environment with high radioactivity. The Kapton foils manufacturer, Du Pont Inc., claims that the foils are radioactive resistant. To verify whether the GEM detector performance is affected by the exposure to radiation, several GEM foils were irradiated to a {sup 60}Co source at the gamma-ray irradiation facility at Sterigenics, Tustin, CA. Four sets of GEM foils were exposed to the level of 10 kGy, 100 kGy, 1,000 kGy and 10,000 kGy. The output signal from the GEM detectors with irradiated GEM foils were measured and compared to the detector with no irradiation. We observed that the shapes of the peaks from 5.9 KeV {sup 55}Fe X-ray were distorted and that the detector gain increased compared to that of the un-irradiated detector. In particular, the detector with 10,000 kGy irradiation appeared to have the biggest peak distortion and increased gain. It was also found from that additional electrons from radiation-induced free radicals in the Kapton film contribute to output signal of the irradiated GEM detectors. Further studies are needed to explain the mechanism of these detector performance changes.

  8. Plastic scintillator-based radiation detector for mobile radiation detection system against nuclear\\/radiological terrorism

    Microsoft Academic Search

    Sung-Woo Kwak; Ho-Sik Yoo; Sung Soon Jang; Jung Soo Kim; Wan-Ki Yoon; In Sub Jun; Kwang Hyun Kim

    2009-01-01

    Illicit trafficking of nuclear or radioactive materials has become a serious world wide problem. Due to operational constraints of radiation detection system for such nuclear security application, a radiation detector with large effective area is needed to maximize its sensitivity. This paper suggests a new method of using plastic scintillation detector as a cost-effective mobile radiation detection system. Monte Carlo

  9. Silicon radiation detector fabricated in a standard IC process

    Microsoft Academic Search

    S. E. Wouters; T. Otaredian; E. M. Schooneveld

    1991-01-01

    The authors present a silicon radiation detector for nuclear radiation, fabricated in a standard IC process, in which the generated charge carriers are collected by means of diffusion. A model is derived and experiments with optical and nuclear radiation are presented. Ionizing particles can be detected with a reasonable internal efficiency (65%) and response time (<10 ?s), and the spatial

  10. Designing SWORD--SoftWare for Optimization of Radiation Detectors

    Microsoft Academic Search

    Elena I. Novikova; Mark S. Strickman; Chul Gwon; Bernard F. Phlips; Eric A. Wulf; Carrie Fitzgerald; Laurie S. Waters; Russell C. Johns

    2006-01-01

    The software for the optimization of radiation detectors (SWORD) is an integrated system (based on MCNPX [Pelowitz, DB, 2005] and GEANT4 [Agostinelli, S, et al., 2003] 3D Monte Carlo radiation transport codes) useful for the optimization of high energy radiation detection systems. A set of usable sample inputs and analysis algorithms are integrated into the system. Sample inputs include special

  11. A Xylophone Detector of Gravitational Radiation

    NASA Technical Reports Server (NTRS)

    Tinto, Massimo

    1997-01-01

    We discuss spacecraft Doppler tracking searches for gravitational waves in which Doppler data recorded on the ground are linearly combined with Doppler measurements made on board a spacecraft. By using the four-link radio system first proposed by Vessot and Levine, we describe a new method for removing from the combined data the frequency fluctuations due to the Earth troposphere, ionosphere, and mechanical vibrations of the antenna on the ground. This technique provides also a way for reducing by several orders of magnitude, at selected Fourier components, the frequency fluctuations due to other noise sources, such as the clock on board the spacecraft or the antenna and buffeting of the probe by nongravitational forces. In this respect spacecraft Doppler tracking can be regarded as a xylophone detector of gravitational radiation. In the assumption of calibrating the frequency fluctuations induced by the interplanetary plasma, a strain sensitivity equal to 4.7 x 10(exp -18) at 10(exp -3) Hz is estimated. This experimental technique could be extended to other tests of the theory of relativity, and to radio science experiments that rely on high-precision Doppler measurements.

  12. Heat Transfer Issues in Thin-Film Thermal Radiation Detectors

    NASA Technical Reports Server (NTRS)

    Barry, Mamadou Y.

    1999-01-01

    The Thermal Radiation Group at Virginia Polytechnic Institute and State University has been working closely with scientists and engineers at NASA's Langley Research Center to develop accurate analytical and numerical models suitable for designing next generation thin-film thermal radiation detectors for earth radiation budget measurement applications. The current study provides an analytical model of the notional thermal radiation detector that takes into account thermal transport phenomena, such as the contact resistance between the layers of the detector, and is suitable for use in parameter estimation. It was found that the responsivity of the detector can increase significantly due to the presence of contact resistance between the layers of the detector. Also presented is the effect of doping the thermal impedance layer of the detector with conducting particles in order to electrically link the two junctions of the detector. It was found that the responsivity and the time response of the doped detector decrease significantly in this case. The corresponding decrease of the electrical resistance of the doped thermal impedance layer is not sufficient to significantly improve the electrical performance of the detector. Finally, the "roughness effect" is shown to be unable to explain the decrease in the thermal conductivity often reported for thin-film layers.

  13. A Silicon Transition Radiation Detector for space and accelerator applications

    NASA Astrophysics Data System (ADS)

    Brigida, M.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Loparco, F.; Marangelli, B.; Mazziotta, M. N.; Mirizzi, N.; Rainò, S.; Spinelli, P.

    2006-08-01

    We have developed an unconventional Transition Radiation Detector (SiTRD) based on silicon strip detectors (SSDs) operating inside a magnetic field. In this way, the path of the radiating particle is deflected with respect to the transition radiation X-rays that convert in a detector region far away from the charged particle track. In this paper we will show the results of a beam test performed at low momenta, up to 5 GeV/c, with a reduced scale detector prototype. We have also implemented a full Monte Carlo simulation to design a SiTRD for an accelerator or a cosmic ray experiment at higher momenta, up to 100 GeV/c. We have simulated two different detector configurations and we have studied their performance.

  14. Thermal treatment of CdTe surfaces for radiation detectors

    Microsoft Academic Search

    T. Ozaki; Y. Iwase; H. Takamura; M. Ohmori

    1996-01-01

    In order to decrease the leakage current of In\\/CdTe\\/Au radiation detectors, thermal treatment of the CdTe wafers was introduced into the detector fabrication process. Detectors were fabricated from Cl-doped THM-grown high-resistivity wafers. The thermal treatment was carried out in a vacuum evaporator at 200–300°C before deposition of the In electrode. An Au electrode was formed by electroless plating. The thermal

  15. Position-sensitive scintillation detectors of nuclear radiation (Review)

    SciTech Connect

    Akimov, Yu.K. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    1995-05-01

    The techniques for detecting nuclear radiation using nontraditional light detectors, such as image converters, multichannel vacuum and solid-state photomultiplers, avalanche photodiodes, and photosensitive chambers with gas amplification are reviewed. Most of the paper is dedicated to tracking detectors with organic scintillating fibers. Devices with capillaries filled with a liquid scintillator are also considered. Position-sensitive detectors built around scintillating inorganic single crystals and glasses are described.

  16. DQE as detection probability of the radiation detectors

    Microsoft Academic Search

    Giovanni Zanella

    2008-01-01

    In this paper it is shown that quantum efficiency (DQE), as commonly defined for imaging detectors, can be extended to all radiation detectors with the meaning of detection probability, if Poisson statistics applies. This unified approach is possible in time-domain at zero spatial-frequency.

  17. Advances in gas avalanche radiation detectors for biomedical applications

    E-print Network

    primary ionization statistics and #uctuations in the avalanche process, low detection e$ciency for enerAdvances in gas avalanche radiation detectors for biomedical applications A. Breskin* Department of Particle Physics, The Weizmann Institute of Science, 76100 Rehovot, Israel Abstract Gas avalanche detectors

  18. Improved Infrared Response Measurements in Semiconductor Nuclear Radiation Detectors

    Microsoft Academic Search

    A. H. Sher; W. J. Keery; H. E. Dyson

    1972-01-01

    An infrared response technique has been developed wnich has been shown to yield more detailed spectra than previous techniques and which can be used to identify more specifically energy levels arising from unwanted impurities and defects in semiconductor diodes used as nuclear radiation detectors. The presence of known impurities in germanium detectors, both lithium-compensated and high purity (uncompensated), has been

  19. High purity liquid phase epitaxial gallium arsenide nuclear radiation detector

    Microsoft Academic Search

    Dimitri Alexiev; K. S. A. Butcher

    1992-01-01

    Surface barrier radiation detector made from high purity liquid phase epitaxial gallium arsenide wafers have been operated as X- and gamma-ray detectors at various operating temperatures. Low energy isotopes are resolved including 241Am at 40°C and the higher gamma energies of 235U at -80°C.

  20. Analysis of semiconductor nuclear radiation detectors with arbitrary electrode geometries

    Microsoft Academic Search

    J. F. Butler; C. L. Lingren

    1998-01-01

    This paper develops a theoretical framework and sets of differential and integral equations for analyzing the operating characteristics of semiconductor nuclear radiation detectors with arbitrary electrode geometries. Results provide a basis for conceptualization and numerical calculations and are relevant to recent substantial improvements in detector performance achieved through various single-carrier charge collection schemes based on special electrode configurations. During the

  1. The role of contacts in semiconductor gamma radiation detectors

    Microsoft Academic Search

    Uri Lachish

    1998-01-01

    It is proposed that the operation of semiconductor gamma radiation detectors, equipped with ohmic contacts, which allow free electron flow between the contacts and bulk material, will not be sensitive to low hole mobility, hole collection efficiency, or hole trapping. Such fast-operating detectors may be readily integrated into monolithic arrays. The detection mechanism and various material aspects are discussed and

  2. Bismuth iodide (III) crystals for nuclear radiation detectors

    Microsoft Academic Search

    M. Matsumoto; K. Hitomi; T. Shoji; Y. Hiratate

    2001-01-01

    Bismuth tri-iodide (BiI3) is an attractive material for room temperature radiation detectors because of its wide bandgap energy and high photon stopping power. In this study, BiI3 crystals have been grown by the vertical Bridgman technique using commercially available powder. The grown crystals have been characterized in terms of their structural properties and stoichiometry. Room temperature radiation detectors have been

  3. Bismuth tri-iodide crystal for nuclear radiation detectors

    Microsoft Academic Search

    Manabu Matsumoto; Keitaro Hitomi; Tadayoshi Shoji; Yukio Hiratate

    2002-01-01

    Bismuth tri-iodide (BiI3) is an attractive material for room temperature radiation detectors because of its wide bandgap energy and high photon stopping power. In this paper, BiI3 crystals have been grown by the vertical Bridgman technique using commercially available powder. The grown crystals have been characterized in terms of their structural properties and stoichiometry. Room temperature radiation detectors have been

  4. Cryogenic Si detectors for ultra radiation hardness in SLHC environment

    Microsoft Academic Search

    Zheng Li; M. Abreu; P. Anbinderis; T. Anbinderis; N. D’. Ambrosio; W. de Boer; E. Borchi; K. Borer; M. Bruzzi; S. Buontempo; W. Chen; V. Cindro; A. Dierlamm; V. Eremin; E. Gaubas; V. Gorbatenko; E. Grigoriev; F. Hauler; E. Heijne; S. Heising; O. Hempel; R. Herzog; J. Härkönen; I. Ilyashenko; S. Janos; L. Jungermann; V. Kalesinskas; J. Kapturauskas; R. Laiho; P. Luukka; I. Mandic; Rita De Masi; D. Menichelli; M. Mikuz; O. Militaru; T. O. Niinikosky; V. O’. Shea; S. Pagano; S. Paul; K. Piotrzkowski; K. Pretzl; P. Rato Mendes; X. Rouby; G. Ruggiero; K. Smith; P. Sonderegger; P. Sousa; E. Tuominen; E. Tuovinen; E. Verbitskaya; J. Vaitkus; E. Wobst; M. Zavrtanik

    2007-01-01

    Radiation hardness up to 1016neq\\/cm2 is required in the future HEP experiments for most inner detectors. However, 1016neq\\/cm2 fluence is well beyond the radiation tolerance of even the most advanced semiconductor detectors fabricated by commonly adopted technologies: the carrier trapping will limit the charge collection depth to an effective range of 20–30?m regardless of depletion depth. Significant improvement of the

  5. Development of a high-sensitivity radiation detector for chromatography

    Microsoft Academic Search

    J. S. Huber; S. M. Hanrahan; W. W. Moses; S. E. Derenzo; B. W. Reutter; J. P. O'Neil; G. T. Gullberg

    2009-01-01

    Radionuclide techniques will be increasingly important for the development of biofuels, since they can both uniquely characterize metabolic pathways and image large model systems. We are investigating the application of nuclear medical imaging tools and techniques to biofuel development, using high-sensitivity chromatographic radiation detectors and compounds radiolabeled with short-lived, cyclotron-produced, positron-emitting isotopes (e.g., 11C). The application of high-sensitivity radiation detectors

  6. Radiation hardness of cryogenic silicon detectors

    Microsoft Academic Search

    T. O Niinikoski; M. Abreu; W. Bell; P. Berglund; W de Boer; E. Borchi; K. Borer; M. Bruzzi; S. Buontempo; L. Casagrande; S. Chapuy; V. Cindro; P. Collins; N D’Ambrosio; C Da Viá; S. R. H Devine; B. Dezillie; Z. Dimcovski; V. Eremin; A. Esposito; V. Granata; E. Grigoriev; S. Grohmann; F. Hauler; E. Heijne; S. Heising; S. Janos; L. Jungermann; I. Konorov; Z. Li; C. Lourenço; M. Mikuz; V O’Shea; S. Pagano; V. G Palmieri; S. Paul; S. Pirollo; K. Pretzl; P. Rato Mendes; G. Ruggiero; K. Smith; P. Sonderegger; P. Sousa; E. Verbitskaya; S. Watts; M. Zavrtanik

    2002-01-01

    We shall review test results which show that silicon detectors can withstand at 130K temperature a fluence of 2×1015cm–2 of 1MeV neutrons, which is about 10 times higher than the fluence tolerated by the best detectors operated close to room temperature. The tests were carried out on simple pad devices and on microstrip detectors of different types. The devices were

  7. Author's personal copy Monte Carlo methods for design and analysis of radiation detectors

    E-print Network

    Shultis, J. Kenneth

    Author's personal copy Monte Carlo methods for design and analysis of radiation detectors William L Radiation detectors Inverse problems Detector design a b s t r a c t An overview of Monte Carlo as a practical method for designing and analyzing radiation detectors is provided. The emphasis is on detectors

  8. Characterisation of bubble detectors for aircrew and space radiation exposure.

    PubMed

    Green, A R; Bennett, L G I; Lewis, B J; Tume, P; Andrews, H R; Noulty, R A; Ing, H

    2006-01-01

    The Earth's atmosphere acts as a natural radiation shield which protects terrestrial dwellers from the radiation environment encountered in space. In general, the intensity of this radiation field increases with distance from the ground owing to a decrease in the amount of atmospheric shielding. Neutrons form an important component of the radiation field to which the aircrew and spacecrew are exposed. In light of this, the neutron-sensitive bubble detector may be ideal as a portable personal dosemeter at jet altitudes and in space. This paper describes the ground-based characterisation of the bubble detector and the application of the bubble detector for the measurement of aircrew and spacecrew radiation exposure. PMID:16987919

  9. Recent advances in compound semiconductor radiation detectors

    Microsoft Academic Search

    Paul J Sellin

    2003-01-01

    Recent developments in compound semiconductor detectors are reviewed, highlighting the latest spectroscopic performance from devices fabricated from a range of wide bandgap materials. Cadmium zinc telluride and cadmium telluride continue to dominate the field, with a range of prototype imaging detectors under development, principally for nuclear medicine and X-ray astronomy applications. Improvements in material quality and supply plus metal–semiconductor contact

  10. Diamond radiation detectors I. Detector properties for IIa diamond

    SciTech Connect

    Kania, D.R.

    1997-05-16

    The detector properties and carrier dynamics of type IIa diamonds are reasonably well understood. The trends in the electron and hole mobilities have been characterized as a function of temperature, impurity content, electric field and carrier density. The carrier lifetimes are coupled through the nitrogen impurity. This leaves us with typical samples with collection distances of 20 to 50 micrometers. The detailed dynamics of the carriers can be modeled using a rate equation analysis. Much progress has been made in understanding the detector properties of diamond, but continued progress has been limited by the geologic processes used to make the material, for example sample size and no synthesis control. CVD diamond promises to eliminate these restrictions.

  11. The pin detector - A simple, robust, cheap and effective nuclear radiation detector

    Microsoft Academic Search

    J. E. Bateman

    1985-01-01

    The development of a series of radiation detectors based on the point anode is reported. Using readily available preformed pins from a variety of electrical connectors as the anodes, a family of devices has been created with useful properties as X-ray detectors, radiation monitors and internal beta counters. A wide variety of gas fillings can be used, argon\\/CH4 premix being

  12. Proton-induced radiation damage in germanium detectors

    NASA Technical Reports Server (NTRS)

    Brueckner, J.; Koerfer, M.; Waenke, H.; Schroeder, A. N. F.; Filges, D.; Dragovitsch, P.; Englert, P. A. J.; Starr, R.; Trombka, J. I.

    1991-01-01

    High-purity germanium (HPGe) detectors will be used in future space missions for gamma-ray measurements and will be subject to interactions with energetic particles. To simulate this process, several large-volume n-type HPGe detectors were incrementally exposed to a particle fluence of up to 10 to the 8th protons/sq cm (proton energy: 1.5 GeV) at different operating temperatures (90 to 120 K) to induce radiation damage. Basic scientific and engineering data on detector performance were collected. During the incremental irradiation, the peak shape produced by the detectors showed a significant change from a Gaussian shape to a broad complex structure. After the irradiation, all detectors were thoroughly characterized by measuring many parameters. To remove the accumulated radiation damage, the detectors were stepwise-annealed at temperatures below 110 C, while kept in their specially designed cryostats. This study shows that n-type HPGe detectors can be used in charged-particle environments as high-energy resolution devices until a certain level of radiation damage is accumulated and that the damage can be removed at moderate annealing temperatures and the detector returned to operating condition.

  13. A hybrid radiation detector for simultaneous spatial and temporal dosimetry.

    PubMed

    Poole, C; Trapp, J V; Kenny, J; Kairn, T; Williams, K; Taylor, M; Franich, R; Langton, C M

    2011-09-01

    In this feasibility study an organic plastic scintillator is calibrated against ionisation chamber measurements and then embedded in a polymer gel dosimeter to obtain a quasi-4D radiation detector. This hybrid dosimeter was irradiated with megavoltage x-rays from a linear accelerator, with temporal measurements of the dose rate being acquired by the scintillator and spatial measurements acquired with the gel dosimeter. The detectors employed in this study are radiologically equivalent; and we show that neither detector perturbs the intensity of the radiation field of the other. By employing these detectors in concert, spatial and temporal variations in the radiation intensity can now be detected and gel dosimeters can be calibrated for absolute dose from a single irradiation. PMID:21678102

  14. Development of position sensitive radiation detectors using gas electron multipliers.

    PubMed

    Park, Seongtae; Hahn, Chang Hie

    2009-01-01

    Gas electron multipliers (GEM) were introduced to develop a radiation detector which is applicable to medical imaging or luggage inspection systems at the airport or harbor. Two GEM foils were used in the amplifier, and an Ar/CO(2) mixed gas was inserted into the chamber at a mixing ratio of Ar:CO(2)=80:20. A two-dimensional X-ray image was taken with a 64-channel GEM detector from an Fe-55 radiation source. We also constructed a 256-channel GEM detector in which 4 charge sensitive preamplifiers were used in a daisy chain. With linear array type readout electrodes, we were able to realize a position sensitive radiation detector. PMID:19282195

  15. Using cumulants and spectra to model nuclear radiation detectors

    Microsoft Academic Search

    Eduardo Winston Pontes; Ademar Ferreira

    2006-01-01

    A general mathematical methodology is presented to model a nuclear radiation detector. This is accomplished by using a proposed generalization of Campbell's theorem, which employs nth-order cumulants and spectra analysis and a vector of random parameters to describe the current pulses. This allows a more elaborate, higher order statistical characterization of the radiation detection process, as compared to the usual

  16. Polarization Phenomena in CdTe Nuclear Radiation Detectors

    Microsoft Academic Search

    H. L. Malm; M. Martini

    1974-01-01

    Nuclear radiation detectors made from high resistivity chlorine doped cadmium telluride grown by the travelling heater method were evaluated. Short term performance for ¿, ??, and ¿ radiations was good but the long term performance (>1 min) was degraded by a decrease in the full energy pulse height and ¿-ray efficiency with time after the bias voltage was applied. A

  17. Ionization detector with improved radiation source. [fire detection

    Microsoft Academic Search

    1977-01-01

    The detector comprises a chamber having at least one radiation source disposed therein. The chamber includes spaced collector plates which form a part of a detection circuit for sensing changes in the ionization current in the chamber. The radiation source in one embodiment is in the form of a wound wire or ribbon suitably supported in the chamber and preferably

  18. Design of a transition radiation detector for cosmic rays

    NASA Technical Reports Server (NTRS)

    Hartmann, G.; Mueller, D.; Prince, T.

    1975-01-01

    Transition radiation detectors consisting of sandwiches of plastic foam radiators and multiwire proportional chambers can be used to identify cosmic ray particles with energies gamma ? E/mc-squared is greater than 10 to the 3rd and to measure their energy in the region gamma is roughly equal to 10 to the 3rd

  19. Integrated nuclear radiation detector and monitor

    Microsoft Academic Search

    B. L. Biehl; S. I. Lieberman

    1982-01-01

    A battery powered device which can continuously monitor and detect nuclear radiation utilizing fully integrated circuitry and which is provided with an alarm which alerts persons when the radiation level exceeds a predetermined threshold.

  20. Nuclear radiation-warning detector that measures impedance

    DOEpatents

    Savignac, Noel Felix; Gomez, Leo S; Yelton, William Graham; Robinson, Alex; Limmer, Steven

    2013-06-04

    This invention is a nuclear radiation-warning detector that measures impedance of silver-silver halide on an interdigitated electrode to detect light or radiation comprised of alpha particles, beta particles, gamma rays, X rays, and/or neutrons. The detector is comprised of an interdigitated electrode covered by a layer of silver halide. After exposure to alpha particles, beta particles, X rays, gamma rays, neutron radiation, or light, the silver halide is reduced to silver in the presence of a reducing solution. The change from the high electrical resistance (impedance) of silver halide to the low resistance of silver provides the radiation warning that detected radiation levels exceed a predetermined radiation dose threshold.

  1. Radiation hardness of high resistivity magnetic Czochralski silicon detectors after gamma, neutron, and proton radiations

    Microsoft Academic Search

    Zheng Li; Jaakko Harkonen; Wei Chen; J. Kierstead; Panja Luukka; Eija Tuominen; Etuovine Tuovinen; Elea Verbitskaya; Vladimir Eremin

    2004-01-01

    High resistivity magnetic Czochralski Si detectors were irradiated with 60Co gamma rays, neutrons, and protons to various doses\\/fluences, along with control float zone Si detectors. 1) It has been found that for gamma radiation, magnetic Czochralski Si detectors behave similarly to the high-temperature, long-time (HTLT) oxygenated float zone Si detectors. There is no space charge sign inversion and there is

  2. The charged particle response of silicon carbide semiconductor radiation detectors

    Microsoft Academic Search

    Frank H. Ruddy; Abdul R. Dulloo; John G. Seidel; John W. Palmour; Ranbir Singh

    2003-01-01

    Silicon carbide (SiC) radiation detectors are being developed for high-temperature applications in harsh radiation environments. The wide band gap of SiC (3.25eV) compared to conventional semiconductors such as silicon (1.1eV) and the relatively high-radiation resistance of SiC make it a semiconductor, that is highly suited for such applications. In this paper, we report on charged particle response measurements with larger-sized

  3. Recent progress in the development of transition radiation detectors

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.; Hartmann, G.; Prince, T.; Mueller, D.

    1978-01-01

    Transition-radiation detectors have been used in several recent cosmic-ray experiments for particle identification at energies E/mc-squared of at least about 1000. In order to optimize the design of such detectors and to use them for energy measurements over a broad energy range, it is necessary to study the details of the transition-radiation process. Experimental results are presented which test the theoretical predictions more precisely and at higher energies than in previous experiments. The dependence of the interference pattern in the frequency spectrum on the radiator dimensions is studied, and the total transition-radiation yield generated by electrons in various radiators is measured over a very wide energy range, from 5 to 300 GeV. The significance of the individual experimental parameters in the design of transition radiation detectors is reviewed, and the characteristics of transition-radiation detectors capable of measuring particle energies over the range E/mc-squared from about 300 to 100,000 are discussed.

  4. Recent advances in compound semiconductor radiation detectors

    NASA Astrophysics Data System (ADS)

    Sellin, Paul J.

    2003-11-01

    Recent developments in compound semiconductor detectors are reviewed, highlighting the latest spectroscopic performance from devices fabricated from a range of wide bandgap materials. Cadmium zinc telluride and cadmium telluride continue to dominate the field, with a range of prototype imaging detectors under development, principally for nuclear medicine and X-ray astronomy applications. Improvements in material quality and supply plus metal-semiconductor contact technologies are discussed, as is the continued development of single polarity charge sensing electrode structures. Other material systems are also reviewed, covering the latest results from intermediate- Z materials such as gallium arsenide and indium phosphide, and high- Z materials including mercuric iodide and thallium bromide. The technological challenges of these materials are summarised and the prospects for future imaging array detectors highlighted.

  5. Background radiation measurement with water Cherenkov detectors

    NASA Astrophysics Data System (ADS)

    Bertou, X.; Pierre Auger Collaboration

    2011-05-01

    Water Cherenkov Detectors have the nice property of being mostly calorimeters for cosmic ray induced electrons and photons, while providing a clear signal for muons. At large energy deposited in the detector, they observe small extended air showers. This makes them interesting detectors to study the background of cosmic ray secondaries. Using low threshold scaler counters, one can follow the flux of cosmic rays on top of the atmosphere, and/or study atmospheric effects on the cosmic ray shower development. In this paper, background data from the Pierre Auger Observatory are presented. These data are searched for short time-scale variation (one second scale, as expected from Gamma Ray Bursts), and larger time-scale variations, showing modulation effects due to Solar activity (Forbush decreases). Rapid changes in the background flux are also observed during the crossing of storms over the 3000 km 2 of the ground array.

  6. AN IN-PHANTOM RADIATION DETECTOR

    Microsoft Academic Search

    Majic S. Potsaid; Goro Irie

    1961-01-01

    A solid system capable of detecting as well as measuring the amount of ; radiation absorbed, and composed of several easily controlled organic molecules ; that can be prepared economically, was devised for experimental and clinical ; applications. It permits the study of radiation effects in a material whose ; density can be made closely equivalent to that of living

  7. MEGA: a low-background radiation detector

    Microsoft Academic Search

    Kareem Kazkaz; Craig E. Aalseth; Todd W. Hossbach; Victor M. Gehman; Jeremy D. Kephart; Harry S. Miley

    2004-01-01

    The multiple-element gamma assay (MEGA) is a low-background detector designed to support environmental monitoring and national security applications. MEGA also demonstrates technology needed for Majorana, a next generation neutrino mass experiment. It will employ active and passive shielding to reduce backgrounds. It will also exploit multicoincidence signatures to identify specific radioactive isotopes. MEGA is expected to begin testing in late

  8. Method for manufacturing nuclear radiation detector with deep diffused junction

    Microsoft Academic Search

    Hall

    1977-01-01

    Germanium radiation detectors are manufactured by diffusing lithium into high purity p-type germanium. The diffusion is most readily accomplished from a lithium-lead-bismuth alloy at approximately 430°C and is monitored by a quartz half cell containing a standard composition of this alloy. Detectors having n-type cores may be constructed by converting high purity p-type germanium to n-type by a lithium diffusion

  9. High resolution room temperature ionization chamber xenon gamma radiation detector

    Microsoft Academic Search

    Gary Tepper; Jon Losee

    1995-01-01

    A unique thin walled dual-type gridded ionization chamber gamma radiation detector using ultra pure Xe gas as the detection medium is described. The detector was operated at room temperature and the energy spectra of 60Co, 137Cs, 22Na and 133Ba were obtained. An energy resolution of (16 keV) 2.4% FWHM was determined for the 662 keV 137Cs gamma peak which is

  10. A comprehensive analysis of low-resistivity silicon radiation detectors

    Microsoft Academic Search

    D. Passeri; G. M. Bilei; P. Ciampolini

    1999-01-01

    Low-resistivity materials have been proposed for the fabrication of radiation-hard solid-state particle detectors. A complete analysis of low-resistivity detector performance, including the estimate of charge collection efficiency, has been carried out by using a numerical device simulator, and compared with results expected from conventional, high-resistivity devices. By exploiting the features of the CAD environment, characterization of devices over a wide

  11. Radiation hardness of three-dimensional polycrystalline diamond detectors

    NASA Astrophysics Data System (ADS)

    Lagomarsino, Stefano; Bellini, Marco; Corsi, Chiara; Cindro, Vladimir; Kanxheri, Keida; Morozzi, Arianna; Passeri, Daniele; Servoli, Leonello; Schmidt, Christian J.; Sciortino, Silvio

    2015-05-01

    The three-dimensional concept in particle detection is based on the fabrication of columnar electrodes perpendicular to the surface of a solid state radiation sensor. It permits to improve the radiation resistance characteristics of a material by lowering the necessary bias voltage and shortening the charge carrier path inside the material. If applied to a long-recognized exceptionally radiation-hard material like diamond, this concept promises to pave the way to the realization of detectors of unprecedented performances. We fabricated conventional and three-dimensional polycrystalline diamond detectors, and tested them before and after neutron damage up to 1.2 ×1016 cm-2, 1 MeV-equivalent neutron fluence. We found that the signal collected by the three-dimensional detectors is up to three times higher than that of the conventional planar ones, at the highest neutron damage ever experimented.

  12. Silicon carbide detector for laser-generated plasma radiation

    NASA Astrophysics Data System (ADS)

    Bertuccio, Giuseppe; Puglisi, Donatella; Torrisi, Lorenzo; Lanzieri, Claudio

    2013-05-01

    We present the performance of a Silicon Carbide (SiC) detector in the acquisition of the radiation emitted by laser generated plasmas. The detector has been employed in time of flight (TOF) configuration within an experiment performed at the Prague Asterix Laser System (PALS). The detector is a 5 mm2 area 100 nm thick circular Nisbnd SiC Schottky junction on a high purity 4Hsbnd SiC epitaxial layer 115 ?m thick. Current signals from the detector with amplitudes up to 1.6 A have been measured, achieving voltage signals over 80 V on a 50 ? load resistance with excellent signal to noise ratios. Resolution of few nanoseconds has been experimentally demonstrated in TOF measurements. The detector has operated at 250 V DC bias under extreme operating conditions with no observable performance degradation.

  13. The Dielectric Bolometer, A New Type of Thermal Radiation Detector

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.

    1960-01-01

    Thermal detectors for the infrared, such as thermocouples and bolometers, are limited in their ultimate sensitivity predominantly by Johnson noise rather than temperature noise. Low noise figures are hard to achieve since Johnson noise preponderates temperature noise, which is the only essential noise for thermal detectors. The dielectric constants of some materials are sufficiently temperature dependent to make a new type of bolometer feasible. The basic theory of a dielectric bolometer, as shown here, promises noise figures below 3 decibels even at chopper frequencies well above the 1/tau value of the detector. Ferroelectrics such as barium-strontium titanate and others seem to be well suited for radiation-cooled dielectric bolometers.

  14. Organic semiconductors as real-time radiation detectors

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Miyata, H.; Katsumata, M.; Nakano, S.; Matsuda, K.; Tamura, M.

    2014-11-01

    In this study, the possibility of using ?-conjugated organic semiconducting polymers as real-time radiation detectors was explored. Polyaniline (PAni) was used to fabricate radiation sensors because of its relative long-term stability in air. Each fabricated sensor was then subjected to irradiation by ?- and ?-particles, and the real-time response was measured. The multichannel analyzer (MCA) data of the response signal for each irradiation was acquired and the detection efficiency, relative to the electrode bias voltage of the detector, was extracted.

  15. MEGA: a low-background radiation detector

    Microsoft Academic Search

    Kareem Kazkaz; Craig E. Aalseth; Todd W. Hossbach; Victor M. Gehman; Jeremy D. Kephart; Harry S. Miley

    2003-01-01

    The Multiple-Element Gamma Assay (MEGA) is a low-background detector designed to support environmental monitoring and national security applications. MEGA also demonstrates technology needed for Majorana, a next generation neutrino mass experiment. It will employ active and passive shielding to reduce backgrounds. It will also exploit multi-coincidence signatures to identify specific radioactive isotopes. MEGA is expected to begin operation in late

  16. MEGA: A Low-Background Radiation Detector

    SciTech Connect

    Kazkaz, Kareem; Aalseth, Craig E.; Hossbach, Todd W.; Gehman, Victor M.; Kephart, Jeremy; Miley, Harry S.

    2004-06-01

    The multiple-element gamma assay (MEGA) is a low-background detector designed to support environmental monitoring and national security applications. MEGA also demonstrates technology needed or Majorana, a next generation neutrino mass experiment. It will also exploit multicoincidence signatures to identify specific radioactive isotopes. MEGA is expected to begin testing in late 2003 for eventual installation at the Waste Isolation Plant, Carlsbad, NM.

  17. (Effects of ionizing radiation on scintillators and other particle detectors)

    SciTech Connect

    Proudfoot, J.

    1992-01-01

    It is my task to summarise the great variety of topics (covering a refreshing mix of physics, chemistry and technology) presented at this conference, which has focused on the effects of ionising radiation on scintillators and other particle detectors. One of the reasons and the central interest of many of the participants was the use of such detectors in experiments at two future large hadron colliders: the Superconducting Super Collider to be operating outside of Dallas in the United States by the turn of the decade and its European counterpart the Large Hadron Collider to be operating outside of Geneva in Switzerland on a similar time scale. These accelerators are the apple of the high energy physicist's eye.'' Their goal is to uncover the elusive Higgs particle and thereby set the cornerstone in our current knowledge of elementary particle interactions. This is the Quest, and from this lofty height the presentations rapidly moved on to the specific questions of experimental science: how such an experiment is carried out; why radiation damage is an issue; how radiation damage affects detectors; which factors affect radiation damage characteristics; which factors are not affected by radiation damage; and how better detectors may be constructed. These were the substance of this conference.

  18. Current injected detectors (CID) - a new approach for detector operation in very high radiation environment

    Microsoft Academic Search

    V. Eremin; I. Ilyashenko; E. Verbitskaya; N. Egorov; S. Golubkov; K. Konkov; A. Sidorov; Z. Li; K. M. Smith; T. Niinikoski; J. Haerkonen

    2004-01-01

    For the upcoming Super LHC (SLHC) experiments on the LHC upgrade, Si detectors will still be considered as the main detectors for inner tracker. However, the radiation level in SLHC will be up to 10 times more than that in LHC due to the increase of luminosity from 1034 cm-2s-1 to 1035 cm-2s-1. In this study a new approach for

  19. Applications of a-Si:H radiation detectors

    SciTech Connect

    Fujieda, I.; Cho, G.; Conti, M.; Drewery, J.; Kaplan, S.N.; Perez-Mendez, V.; Qureshi, S.; Street, R.A.

    1989-07-01

    Device structures and operation principles are described for detecting various kinds of radiation with hydrogenated amorphous silicon (a-Si:H) layers. With some new configurations such as the buried p-i-n structure and the use of interdigitated electrodes, the a-Si:H radiation detectors will find their applications in many fields of science. Some applications in high energy physics, medical imaging, materials sciences and life sciences are discussed in this paper. 41 refs., 7 figs., 1 tab.

  20. Recent progress in the transition radiation detector techniques

    NASA Technical Reports Server (NTRS)

    Yuan, L. C. L.

    1973-01-01

    A list of some of the major experimental achievements involving charged particles in the relativistic region are presented. With the emphasis mainly directed to the X-ray region, certain modes of application of the transition radiation for the identification and separation of relativistic charged particles are discussed. Some recent developments in detection techniques and improvements in detector performances are presented. Experiments were also carried out to detect the dynamic radiation, but no evidence of such an effect was observed.

  1. Practical theory of the multilayered transition radiation detector

    Microsoft Academic Search

    X. Artru; G. B. Yodh; G. Mennessier

    1975-01-01

    The transition-radiation detector with a multifoil radiator for ultrarelativistic particles is studied in the following aspects: X-ray spectrum, Lorentz-factor (gamma) dependence, interference effects, saturation at high gamma, effects of irregularities, and multiple scattering. The analysis is simplified by reducing the various parameters to essentially three dimensionless quantities: a scaled Lorentz factor, a scaled frequency, and the ratio of foil spacing

  2. Performance of the E715 transition radiation detector

    SciTech Connect

    Denisov, A.; Grachev, V.; Kulikov, A.; Schegelsky, V.; Seliverstov, D.; Smirnov, N.; Terentyev, N.; Tkatch, I.; Vorobyov, A.; Hsueh, S.Y.

    1984-01-01

    The transition radiation detector (TRD) consisted of 12 identical modules, each containing a radiator and a multiwire proportional counter (MWPC). A TRD is found to be an effective device for the identification of electrons in a large hadron background at Tevatron energies. The TRD proved to be a stable and reliable device with performance parameters in close agreement with theoretical predictions. The combination of a TRD with a lead glass calorimeter proved to be a very powerful method of electron identification. (LEW)

  3. BIBLIOGRAPHY ON SEMICONDUCTOR NUCLEAR RADIATION DETECTORS

    Microsoft Academic Search

    J. L. Blankenship; H. D. comps. Raleigh

    1962-01-01

    A bibliography on the theory, manufacture, properties, performance, and ; utilization of semiconductor materials for the detection of nuclear radiation is ; presented. The 464 references cover reports and published literature through ; January 1962. The report references are arranged alpha-numerically by report ; number behind the name of the issuing agency. The journal references are ; arranged alphabetically by

  4. Radiation Response of Emerging High Gain, Low Noise Detectors

    NASA Technical Reports Server (NTRS)

    Becker, Heidi N.; Farr, William H; Zhu, David Q.

    2007-01-01

    Data illustrating the radiation response of emerging high gain, low noise detectors are presented. Ionizing dose testing of silicon internal discrete avalanche photodiodes, and 51-MeV proton testing of InGaAs/InAlAs avalanche photodiodes operated in Geiger mode are discussed.

  5. A study of an acrylic Cerenkov radiation detector

    Microsoft Academic Search

    B. Porter; P. Auchincloss; P. de Barbaro; A. Bodek; H. Budd

    1999-01-01

    An experiment investigating the angle of Cerenkov light emitted by 3-MeV electrons traversing an acrylic detector has been developed for use in the advanced physics laboratory course at the University of Rochester. In addition to exploring the experimental phenomena of Cerenkov radiation and total internal reflection, the experiment introduces students to several experimental techniques used in actual high energy and

  6. Mercuric iodide single crystals for nuclear radiation detectors

    Microsoft Academic Search

    Weitang Li; Zhenghui Li; Shifu Zhu; Shujun Yin; Beijun Zhao; Guanxiong Chen; Shi Yin; Hong Yuan; Huapeng Xu

    1996-01-01

    Large size HgI2 single crystals were grown using the modified temperature oscillation method with low dislocation densities in a relatively stable temperature environment. Radiation detectors were fabricated from the single crystals which showed good energy resolution with small polarization

  7. Undoped high-resistivity cadmium telluride for nuclear radiation detectors

    Microsoft Academic Search

    R. Triboulet; Y. Marfaing; A. Cornet; P. Siffert

    1974-01-01

    Starting with highly purified feed material, single crystals of semiinsulating CdTe were grown by the use of the traveling heater method, without external chemical compensation. Evaluation of the crystals by the use of electrical and optical measurements showed decisive improvements in quality. Nuclear radiation detectors prepared by the use of this material resulted in an energy resolution (FWHM), at room

  8. A SMALL, LINEAR, WIDE RANGE NUCLEAR RADIATION DETECTOR

    Microsoft Academic Search

    T. A. Rabson

    1962-01-01

    A simple nuclear radiation detector is produced using a scintillation ; element and a CdS photoresistive cell, which possesses the properties of ; linearity over a wide energy range, small size, and energy independence. Several ; scintillation materials including NaI and Pilot B are tested. (auth);

  9. Mercuric iodide single crystal for nuclear radiation detectors

    Microsoft Academic Search

    Weitang Li; Zhenghui Li; Shifu Zhu; Shujun Yin; Beijun Zhao; Guanxiong Chen; Shi Yin; Hong Yuan; Huapeng Xu

    1995-01-01

    Large size HgI2 single crystals are grown using the modified temperature oscillation method with low dislocation densities in a relatively stable temperature environment. Radiation detectors are fabricated from the single crystals which show good energy resolution with small polarization

  10. From Vacuum Fluctuations to Radiation: Accelerated Detectors and Black Holes

    Microsoft Academic Search

    S. Massar; R. Parentani

    1994-01-01

    The vacuum fluctuations that induce the transitions and the thermalisation of a uniformly accelerated two level atom are studied in detail. Their energy content is revealed through the weak measurement formalism of Aharonov et al. It is shown that each time the detector makes a transition it radiates a Minkowski photon. The same analysis is then applied to the conversion

  11. IceCube: A Cubic Kilometer Radiation Detector

    E-print Network

    Spencer R. Klein; for the IceCube Collaboration

    2008-12-01

    IceCube is a 1 km^3 neutrino detector now being built at the Amundsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate \

  12. Characterization of thallium bromide crystals for radiation detector applications

    Microsoft Academic Search

    K. Hitomi; M Matsumoto; O Muroi; T Shoji; Y Hiratate

    2001-01-01

    In this study, thallium bromide (TlBr) crystals have been investigated for radiation detector applications. Thallium bromide crystals have been grown by the traveling molten zone method using materials purified by the conventional zone refining method. The grown crystals have been characterized in terms of their structural properties, stoichiometry and surface properties. Charge transport properties of the grown crystals have also

  13. Electronics and data acquisition in radiation detectors for medical imaging

    Microsoft Academic Search

    João Varela

    2004-01-01

    Electronics and data acquisition systems are important components of radiation detectors applied to medical imaging. The performance of these systems has strong implications on crucial parameters of imaging devices, like the sensitivity and the image background noise. The paper presents a review of the functionality, typical architectures and main components of the electronics and data acquisition systems in medical imaging.

  14. Mercuric iodide single crystals for nuclear radiation detectors

    SciTech Connect

    Li, W.; Li, Z.; Zhu, S.; Yin, S.; Zhao, B.; Chen, G. [Sichuan Univ., Chengdu (China). Material Science Dept.; Yin, S. [Univ. of Southern California, Los Angeles, CA (United States). Physics Dept.; Yuan, H.; Xu, H. [Deyang Mercuric Iodide Single Crystal Plant, Sichuan (China)

    1996-06-01

    Large size HgI{sub 2} single crystals were grown using the Modified Temperature Oscillation Method (MTOM) with low dislocation densities in a relatively stable temperature environment. Radiation detectors were fabricated from the single crystals which showed good energy resolution with small polarization. Applications have been found in geological explorations, marine mineral analysis, environment pollution monitoring, industrial material quality assurance, and space explorations.

  15. Simple classical model for Fano statistics in radiation detectors

    Microsoft Academic Search

    David V. Jordan; Andrea S. Renholds; John E. Jaffe; Kevin K. Anderson; L. René Corrales; Anthony J. Peurrung

    2008-01-01

    A simple classical model that captures the essential statistics of energy partitioning processes involved in the creation of information carriers (ICs) in radiation detectors is presented. The model pictures IC formation from a fixed amount of deposited energy in terms of the statistically analogous process of successively sampling water from a large, finite-volume container (“bathtub”) with a small dipping implement

  16. Development of a High-Sensitivity Radiation Detector for Chromatography

    Microsoft Academic Search

    Jennifer S. Huber; Stephen M. Hanrahan; William W. Moses; Steve E. Derenzo; Bryan W. Reutter; James P. O'Neil; Grant T. Gullberg

    2011-01-01

    We describe a radiotracer imaging system for mea- suring the biochemical production rates of organic compounds from animals or plants. It uses a high performance liquid chro- matography (HPLC) column to separate the compounds and a parallel-plane radiation detector to measure the disintegrations from each compound over a period of time. Because the mea- surement time is much longer than

  17. Simple classical model for Fano statistics in radiation detectors

    Microsoft Academic Search

    David V. Jordan; Andrea S. Renholds; John E. Jaffe; Kevin K. Anderson; L. René Corrales; Anthony J. Peurrung

    2008-01-01

    A simple classical model that captures the essential statistics of energy partitioning processes involved in the creation of information carriers (ICs) in radiation detectors is presented. The model pictures IC formation from a fixed amount of deposited energy in terms of the statistically analogous process of successively sampling water from a large, finite-volume container (``bathtub'') with a small dipping implement

  18. Radiation detector made of a high-quality polycrystalline diamond

    Microsoft Academic Search

    J. H. Kaneko; T. Tanaka; S. Kawamura; Y. Oshiki; K. Tsuji; M. Katagiri; K. Ochiai; T. Nishitani; F. Fujita; A. Homma; T. Sawamura; T. Iida; M. Furusaka

    2005-01-01

    Radiation detector was made of a high-quality CVD polycrystalline diamond composed of frost column like structure diamond grains, and induced charge distribution spectra and drift velocities were measured by using alpha particles. As a result, the CVD polycrystalline achieved maximum induced charge of 83% of HP\\/HT type IIa diamond. Moreover, the CVD crystal had lower charge loss on electrons compared

  19. Compensation of radiation damages for SOI pixel detector via tunneling

    E-print Network

    Yamada, Miho; Kurachi, Ikuo

    2015-01-01

    We are developing monolithic pixel detectors based on SOI technology for high energy physics, X-ray applications and so on.To employ SOI pixel detector on such radiation environments, we have to solve effects of total ionization damages (TID) for transistors which are enclosed in oxide layer.The holes which are generated and trapped in the oxide layers after irradiation affect characteristics of near-by transistors due to its positive electric field.Annealing and radiation of ultraviolet are not realistic to remove trapped holes for a fabricated detector due to thermal resistance of components and difficulty of handling. We studied compensation of TID effects by tunneling using a high-voltage. For decrease of trapped holes, applied high-voltage to buried p-well which is under oxide layer to inject the electrons into the oxide layer.In this report, recent progress of this study is shown.

  20. Synchrotron radiation applications of charge coupled device detectors (invited)

    SciTech Connect

    Clarke, R. (University of Michigan, Department of Physics, Ann Arbor, Michigan 48109-1120 (United States)); Lowe, W.P.; MacHarrie, R.A. (AT T Bell Laboratories, Murray Hill, New Jersey 07974-2070 (United States)); Brizard, C.; Rodricks, B.G. (Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States))

    1992-01-01

    Scientific charge coupled devices (CCDs) offer many opportunities for high brightness synchrotron radiation applications where good spatial resolution and fast data acquisition are important. We describe the use of virtual-phase CCD pixel arrays as two-dimensional area detectors illustrating the techniques with results from recent x-ray scattering, imaging, and absorption spectroscopy studies at NSLS, CHESS, SRC, and LURE DCI. The virtual phase architecture allows direct frontside illumination of the CCD detector chips giving advantages in the speed and sensitivity of the detector. Combining developments in x-ray optics (dispersive geometry), position sensitive area detectors (CCDs), and fast data acquisition, we have been able to perform time-resolved measurements at the microsecond level. Current developments include faster data transfer rates so that the single bunch timing structure of third generation synchrotron sources can be exploited.

  1. Two-dimensional position sensitive radiation detectors

    DOEpatents

    Mihalczo, John T. (Oak Ridge, TN)

    1994-01-01

    Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wave length shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event.

  2. Two-dimensional position sensitive radiation detectors

    DOEpatents

    Mihalczo, J.T.

    1994-02-22

    Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wavelength shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event. 6 figures.

  3. Three-dimensional architecture for solid state radiation detectors

    DOEpatents

    Parker, Sherwood (Berkeley, CA)

    1999-01-01

    A radiation-damage resistant radiation detector is formed on a substrate formed of a material doped with a first conductivity type dopant. The detector includes at least one first electrode formed of first conductivity type dopant, and at least one second electrode that is spaced-apart from the first electrode and formed of a second conductivity type dopant. Each first and second electrode penetrates into the substrate from a substrate surface, and one or more electrodes may penetrate entirely through the substrate, that is traversing from one surface to the other surface. Particulate and/or electromagnetic radiation penetrating at least a surface of the substrate releases electrons and holes in substrate regions. Because the electrodes may be formed entirely through the substrate thickness, the released charges will be a relatively small distance from at least a portion of such an electrode, e.g., a distance less than the substrate thickness. The electrons and/or holes traverse the small distance and are collected by said electrodes, thus promoting rapid detection of the radiation. By providing one or more electrodes with a dopant profile radially graded in a direction parallel to a substrate surface, an electric field results that promotes rapid collection of released electrons and said holes. Monolithic combinations of such detectors may be fabricated including CMOS electronics to process radiation signals.

  4. Three-dimensional architecture for solid state radiation detectors

    DOEpatents

    Parker, S.

    1999-03-30

    A radiation-damage resistant radiation detector is formed on a substrate formed of a material doped with a first conductivity type dopant. The detector includes at least one first electrode formed of first conductivity type dopant, and at least one second electrode that is spaced-apart from the first electrode and formed of a second conductivity type dopant. Each first and second electrode penetrates into the substrate from a substrate surface, and one or more electrodes may penetrate entirely through the substrate, that is traversing from one surface to the other surface. Particulate and/or electromagnetic radiation penetrating at least a surface of the substrate releases electrons and holes in substrate regions. Because the electrodes may be formed entirely through the substrate thickness, the released charges will be a relatively small distance from at least a portion of such an electrode, e.g., a distance less than the substrate thickness. The electrons and/or holes traverse the small distance and are collected by said electrodes, thus promoting rapid detection of the radiation. By providing one or more electrodes with a dopant profile radially graded in a direction parallel to a substrate surface, an electric field results that promotes rapid collection of released electrons and said holes. Monolithic combinations of such detectors may be fabricated including CMOS electronics to process radiation signals. 45 figs.

  5. LC-DET-2000-038 Si-pixel Transition Radiation Detector

    E-print Network

    LC-DET-2000-038 Si-pixel Transition Radiation Detector with separation of TR-photons and particle.Franklin University of Portsmouth, Portsmouth, UK Abstract This proposal describes a Transition Radiation Detector

  6. Super-radiation hard detector technologies: 3-D and widegap detectors

    Microsoft Academic Search

    M. Rahman; A. Al-Ajili; R. Bates; A. Blue; W. Cunningham; F. Doherty; M. Glaser; L. Haddad; M. Horn; J. Melone; M. Mikuz; T. Quinn; P. Roy; V. O'Shea; K. M. Smith; J. Vaitkus; V. Wright

    2004-01-01

    The radiation hardness of semiconductor detectors for harsh environments, including nuclear, space, and particle physics, may be enhanced by a number of strategies. We examine the use of materials alternative to silicon, namely silicon carbide and gallium nitride, as well as a nonconventional geometry called \\

  7. LALP-07-091 Fall 2007 Development of improved radiation detector materials

    E-print Network

    LALP-07-091 Fall 2007 Development of improved radiation detector materials Tailored processing new resolution for a particular special nuclear material detector application, then an alternative processing radiation detectors. The per- formance of these detectors can be significantly enhanced if the materials

  8. Test of radiation detectors used in homeland security applications.

    PubMed

    Pibida, L; Minniti, R; O'Brien, M; Unterweger, M

    2005-05-01

    This work was performed as part of the National Institute of Standards and Technology (NIST) program to support the development of the new American National Standards Institute (ANSI) standards N42.32-2003 and N42.33-2003 for hand-held detectors, and personal electronic dosimeters, as well as to support the Office of Law Enforcement Standards (OLES) and the Department of Homeland Security (DHS) in testing these types of detectors for their use by first responders. These instruments are required to operate over a photon energy range of 60 keV to 1.33 MeV and over a wide range of air-kerma rates. The performance and response of various radiation detectors, purchased by the NIST, was recorded when placed in 60Co, 137Cs, and x-ray beams at different air-kerma rates. The measurements described in this report were performed at the NIST x-ray and gamma-ray radiation calibration facilities. The instruments' response (exposure or dose rate readings) shows strong energy dependence but almost no dependence to different air-kerma rates. The data here reported provide a benchmark in support of current protocols that are being developed for radiation detection instrumentation used in homeland security applications. A future plan is to test these devices, plus other commercially available detectors, against ANSI standards N42.32-2003 and N42.33-2003. PMID:15824588

  9. Device for detachably securing a collimator to a radiation detector

    SciTech Connect

    Hanz, G.J.; Jung, G.; Pflaum, M.

    1986-12-16

    A device is described for detachably securing a collimator to a radiation detector, comprising: (a) a first annular groove means secured to the radiation detector; (b) a second annular groove means secured to the collimator; (c) a split ring having a first and second ring ends, the ring being received in the first annular groove means; and (d) a ring diameter control system, including (d1) a first lever system having two ends; (d2) a second lever system having two ends; and (d3) a rotating hub being rotatably secured to the detector head; wherein the first lever system is rotatably mounted with one end linked to the first ring end and with the other end linked to the rotating hub. The second lever system is rotatably mounted with one end linked to the second ring end and with the other end linked to the rotating hub, such that rotation of the rotating hub moves the first and second lever systems in opposite directions thereby moving the first and second ring ends between a first position, in which the split ring is positioned only in the first annular groove means, and a second position, in which the split ring is located in both the first annular groove means and the second annular groove means, thus attaching the collimator to the radiation detector.

  10. Optimization of efficiency and response time of diffusion-based nuclear radiation detectors

    Microsoft Academic Search

    S. E. Wouters; T. Otaredian; E. M. Schooneveld

    1991-01-01

    The charge collection process in a diffusion-based silicon nuclear radiation detector was investigated by illuminating the detector at the backside with optical radiation. The results are compared to calculations and show good agreement. The collection mechanism is characterized, and the detector response to nuclear radiation and its optimum with respect to efficiency and response time are calculated. Efficiency and response

  11. IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 57, NO. 6, DECEMBER 2010 3795 Femtosecond Radiation Experiment Detector

    E-print Network

    Gruner, Sol M.

    IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 57, NO. 6, DECEMBER 2010 3795 Femtosecond Radiation, radiation detectors, semicon- ductor device measurement, silicon radiation detectors, X-ray de- tector, X Experiment Detector for X-Ray Free-Electron Laser (XFEL) Coherent X-Ray Imaging Hugh T. Philipp, Lucas J

  12. The AMS-02 Transition Radiation Detector to Search for Dark Matter in Space

    E-print Network

    Roma "La Sapienza", Università di

    The AMS-02 Transition Radiation Detector to Search for Dark Matter in Space Francesca Bucci) to measure the primary cosmic rays spectrum in space. A Transition Radiation Detector (TRD) will provide in the energy range of interest. Index Terms-- Transition radiation detector, straw tubes, gas gain, dark matter

  13. The PAMELA Transition Radiation Detector F.S. Cafagna for the PAMELA Collaboration

    E-print Network

    Morselli, Aldo

    OG 4.2.12 The PAMELA Transition Radiation Detector F.S. Cafagna for the PAMELA Collaboration University and INFN, Bari, Italy Abstract A Transition Radiation Detector (TRD) has been developed will be equipped with a transition radiation detector (TRD), that together with a silicon-tungsten calorimeter

  14. AMS Transition Radiation Detector 4-Layer Prototype and Gas System Tests

    E-print Network

    Roma "La Sapienza", Università di

    AMS Transition Radiation Detector 4-Layer Prototype and Gas System Tests Francesca Bucci University of Rome "La Sapienza" September 26 2006 The AMS Transition Radiation Detector (TRD) will provide a proton physics, allowing cross checks among its subdetectors. In particular the Transition Radiation Detector

  15. Examination results of the Three Mile Island radiation detector HP-R-211

    Microsoft Academic Search

    M. B. Murphy; G. M. Mueller; F. V. Thome

    1981-01-01

    An area radiation detector, HP-R-211, which was removed from the Three Mile Island containment building on August 15, 1980 has been examined. The detector had failed at some time following the accident and indicated erroneous, low radiation levels from that point on. This report discusses the cause of failue, detector radiation measurement characteristics, our attempts to reconstruct the gamma rate

  16. Examination results of the Three Mile Island radiation detector HP-R-211

    Microsoft Academic Search

    M. B. Murphy; G. M. Mueller; F. V. Thome

    1981-01-01

    An area radiation detector, HP-R-211, which was removed from the Three Mile Island containment building on August 15, 1980, has been examined. The detector had failed at some time following the accident and indicated erroneous, low radiation levels from that point on. This report discusses the cause of failure, detector radiation measurement characteristics, our attempts to reconstruct the gamma rate

  17. Design of a wire imaging synchrotron radiation detector

    SciTech Connect

    Kent, J.; Gomez-Cadenas, J.J.; Hogan, A.; King, M.; Rowe, W.; Watson, S.; Von Zanthier, C. (California Univ., Santa Cruz, CA (USA)); Briggs, D.D. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)); Levi, M. (Lawrence Berkeley Lab., CA (USA))

    1990-01-01

    This paper documents the design of a detector invented to measure the positions of synchrotron radiation beams for the precision energy spectrometers of the Stanford Linear Collider (SLC). The energy measurements involve the determination, on a pulse-by-pulse basis, of the separation of pairs of intense beams of synchrotron photons in the MeV energy range. The detector intercepts the beams with arrays of fine wires. The ejection of Compton recoil electrons results in charges being developed in the wires, thus enabling a determination of beam positions. 10 refs., 4 figs.

  18. Virtual detector of synchrotron radiation (VDSR) - A C++ parallel code for particle tracking and radiation calculation

    SciTech Connect

    Rykovanov, S. G.; Chen, M.; Geddes, C. G. R.; Schroeder, C. B.; Esarey, E.; Leemans, W. P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley CA 94720 (United States)

    2012-12-21

    The Virtual Detector for Synchrotron Radiation (VDSR) is a parallel C++ code developed to calculate the incoherent radiation from a single charged particle or a beam moving in given external electro-magnetic fields. In this proceedings the code structure and features are introduced. An example of radiation generation from the betatron motion of a beam in the focusing fields of the wake in a laser-plasma accelerator is presented.

  19. Distributed miniature radiation detectors for monitoring plutonium casting processes.

    SciTech Connect

    Huang, J. Y. (John Y.); Vo, Duc T.; Montoya, J. B. (Joseph B.); Flores, A. D. (Anna D.); Velasquez, M. D. (Matthew D.); Martinez, M. M. (Michael M.); Valdez, A. F. (Anthony F.); Martinez, S. C. (Sammy C.); Sandoval, D. P. (Darren P.); Rodriguez, F. (Floyd); Romero, G. (Gilbert); Villareal, D. V. (Doyle V.)

    2004-01-01

    Miniature cadmium-zinc telluride (CZT) detectors are used to monitor plutonium casting processes at the Los Alamos TA-55 Plutonium Facility. Specially designed fixtures provide adequate shielding from background radiation and allow the attachment of the detectors onto the outside surfaces of gloveboxes with minimal intrusion to the operators, the processes, and the facilities. The detectors are located where the process steps and duration are well defined. From the sequence of the detected changes in the signal strength and the elapsed time between changes, the occurrence of casting processes can be distinguished from random movements of special nuclear materials. For the teps that do not require operators continued attendance, this detection system has the potential for safeguarding these materials.

  20. Modelling radiation loads to detectors in a SNAP mission.

    PubMed

    Mokhov, N V; Rakhno, I L; Striganov, S I; Peterson, T J

    2005-01-01

    In order to investigate the degradation of optical detectors of the Supernova Acceleration Project (SNAP) space mission because of irradiation, a three-dimensional model of the satellite has been developed. A realistic radiation environment at the satellite orbit, including both galactic cosmic rays and cosmic ray trapped in radiation belts, has been taken into account. The modelling has been performed with the MARS14 Monte Carlo code. In a current design, the main contribution to dose accumulated in the photo-detectors is shown to be due to trapped protons. The contribution of primary alpha particles is estimated. Predicted performance degradation for the photodetector for a four-year space mission is 40% and this can be reduced further by means of shielding optimisation. PMID:16604632

  1. Calibration of the active radiation detector for Spacelab-One

    SciTech Connect

    Not Available

    1982-12-01

    The flight models of the active radiation detector (ARD) for the ENV-01 environmental monitor were calibrated using gamma radiation. Measured sensitivities of the ion chambers were 6.1 + or - 0.3 micron rad per count for ARD S/N1, and 10.4 + or - 0.5 micron rad per count for ARD S/N2. Both were linear over the measured range 0.10 to 500 m/rad hour. The particle counters (proportional counters) were set to respond to approximately 85% of minimum ionizing particles of unit charge passing through them. These counters were also calibrated in the gamma field.

  2. Calibration of the active radiation detector for Spacelab-One

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The flight models of the active radiation detector (ARD) for the ENV-01 environmental monitor were calibrated using gamma radiation. Measured sensitivities of the ion chambers were 6.1 + or - 0.3 micron rad per count for ARD S/N1, and 10.4 + or - 0.5 micron rad per count for ARD S/N2. Both were linear over the measured range 0.10 to 500 m/rad hour. The particle counters (proportional counters) were set to respond to approximately 85% of minimum ionizing particles of unit charge passing through them. These counters were also calibrated in the gamma field.

  3. Performance of the AMS-02 Transition Radiation Detector

    E-print Network

    P. v. Doetinchem; S. Fopp; W. Karpinski; T. Kirn; K. Luebelsmeyer; J. Orboeck; S. Schael; A. Schultz von Dratzig; G. Schwering; T. Siedenburg; R. Siedling; W. Wallraff; U. Becker; J. Burger; R. Henning; A. Kounine; V. Koutsenko; J. Wyatt

    2006-08-29

    For cosmic particle spectroscopy on the International Space Station the AMS experiment will be equipped with a Transition Radiation Detector (TRD) to improve particle identification. The TRD has 20 layers of fleece radiator with Xe/CO2 proportional mode straw tube chambers. They are supported in a conically shaped octagon structure made of CFC-Al-honeycomb. For low power consumption VA analog multiplexers are used as front-end readout. A 20 layer prototype built from final design components has achieved proton rejections from 100 to 2000 at 90% electron efficiency for proton beam energies up to 250 GeV with cluster counting, likelihood and neural net selection algorithms.

  4. CMOS sensor as charged particles and ionizing radiation detector

    NASA Astrophysics Data System (ADS)

    Cruz-Zaragoza, E.; Piña López, I.

    2015-01-01

    This paper reports results of CMOS sensor suitable for use as charged particles and ionizing radiation detector. The CMOS sensor with 640 × 480 pixels area has been integrated into an electronic circuit for detection of ionizing radiation and it was exposed to alpha particle (Am-241, Unat), beta (Sr-90), and gamma photons (Cs-137). Results show after long period of time (168 h) irradiation the sensor had not loss of functionality and also the energy of the charge particles and photons were very well obtained.

  5. A precision synchrotron radiation detector using phosphorescent screens

    SciTech Connect

    Jung, C.K.; Lateur, M.; Nash, J.; Tinsman, J. (Stanford Linear Accelerator Center, Menlo Park, CA (USA)); Butler, J. (Fermi National Accelerator Lab., Batavia, IL (USA)); Wormser, G. (Paris-11 Univ., 91 - Orsay (France). Lab. de l'Accelerateur Lineaire); Levi, M.; Rouse, F. (Lawrence Berkeley Lab., CA (USA))

    1990-01-01

    A precision detector to measure synchrotron radiation beam positions has been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 {mu}m on a pulse-to-pulse basis. This contributes less than 5 MeV to the error in the measurement of SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. 3 refs., 5 figs., 1 tab.

  6. Indirect Dark Matter Search with AMS Transition Radiation Detector

    Microsoft Academic Search

    Feng Zhou

    2009-01-01

    The Alpha Magnetic Spectrometer (AMS) 02, to be installed on the International Space Station in 2010, will perform a high statistics study of cosmic rays in a large energy range. The Transition Radiation sub-detector (TRD) will provide a positron\\/proton separation up to 300GeV to search for the signatures of neutralino dark matter. The TRD design, test and current cosmic ray

  7. Protective surface coatings on semiconductor nuclear radiation detectors

    Microsoft Academic Search

    W. L. Hansen; E. E. Haller; G. S. Hubbard

    1980-01-01

    Surface states on germanium p-i-n junctions have been investigated using deep level transient spectroscopy (DLTS) and collimated beams of 60 keV gamma-rays. The DLTS spectra have a characteristic signature for each surface treatment but the spectra are complex and not readily interpretable as to suitability for radiation detectors. Collimated gamma-ray beams give a direct measure of surface channel effects and

  8. Double gated-integrator for shaping nuclear radiation detector signals

    Microsoft Academic Search

    J. Gál

    2001-01-01

    A new shaper, the double gated-integrator, for shaping nuclear radiation detector signals is investigated both theoretically and experimentally. The double gated-integrator consists of a pre-filter and two cascaded gated integrators. Two kinds of pre-filters were considered: a rectangular one and an exponential one. The results of the theoretical calculation show that the best figure of demerit for the double gated-integrator

  9. Improved spectrometric characteristics of thallium bromide nuclear radiation detectors

    Microsoft Academic Search

    K. Hitomi; T. Murayama; T. Shoji; T. Suehiro; Y. Hiratate

    1999-01-01

    Thallium bromide (TlBr) is a compound semiconductor with a high atomic number and wide band gap. In this study, nuclear radiation detectors have been fabricated from the TlBr crystals. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using the materials purified by many pass zone refining. The crystals were characterized by measuring the resistivity, the

  10. Protective surface coatings on semiconductor nuclear radiation detectors

    Microsoft Academic Search

    W. L. Hansen; E. E. Haller; G. S. Hubbard

    1979-01-01

    Surface states on germanium p-i-n junctions have been investigated using deep level transient spectroscopy (DLTS) and collimated beams of 60 keV gamma-rays. The DLTS spectra have a characteristic signature for each surface treatment but the spectra are complex and not readily interpretable as to suitability for radiation detectors. Collimated gamma-ray beams give a direct measure of surface channel effects and

  11. Progress in ultra-low-noise ASICs for radiation detectors

    Microsoft Academic Search

    Giuseppe Bertuccio; Stefano Caccia

    2007-01-01

    The progress of a research aimed to design CMOS front-end with noise level down to few electrons r.m.s. is presented. The interest in ultra-low-noise Application-Specific Integrated Circuits (ASICs) has been stimulated by silicon carbide pixel radiation detectors with negligible electronic noise at room temperature due to leakage currents in the femtoampere range. An experimental study on the 1\\/f noise of

  12. Modeling and characterization of polycrystalline mercuric iodide radiation detectors

    Microsoft Academic Search

    Unmesh Khadilkar

    2003-01-01

    The ability of Mercuric Iodide (HgI2) to function as a highly efficient radiation detector at room temperature has generated great interest and has triggered further studies on this difficult material. This property is expected to enable significant enhancements to a far-ranging variety of applications and systems. HgI2 devices have shown superior performance at room temperature compared to elemental Si or

  13. Simple classical model for Fano statistics in radiation detectors

    SciTech Connect

    Jordan, David V.; Renholds, Andrea S.; Jaffe, John E.; Anderson, Kevin K.; Corrales, L. Rene; Peurrung, Anthony J.

    2008-02-01

    A simple classical model that captures the essential statistics of energy partitioning processes involved in the creation of information carriers (ICs) in radiation detectors is presented. The model pictures IC formation from a fixed amount of deposited energy in terms of the statistically analogous process of successively sampling water from a large, finite-volume container (“bathtub”) with a small dipping implement (“shot glass”). The model exhibits sub-Poisson variance in the distribution of the number of ICs generated (the “Fano e_ect”). Elementary statistical analysis of the model clarifies the role of energy conservation in producing the Fano e_ect and yields Fano’s prescription for relating the IC number distribution to the mean and variance of the underlying IC energy distribution. The connection between the model and energy partitioning in semiconductor radiation detectors is illustrated, and the implications of this simple picture for guiding or constraining more detailed, “microscopic” physical models of detector material response to ionizing radiation are discussed.

  14. System for determining the type of nuclear radiation from detector output pulse shape

    Microsoft Academic Search

    William H. Miller; Ronald R. Berliner

    1994-01-01

    A radiation detection system determines the type of nuclear radiation received in a detector by producing a correlation value representative of the statistical cross correlation between the shape of the detector signal and pulse shape data previously stored in memory and characteristic of respective types of radiation. The correlation value is indicative of the type of radiation. The energy of

  15. Radiation tests for a single-GEM-loaded gaseous detector

    NASA Astrophysics Data System (ADS)

    Lee, Kyong Sei; Hong, Byungsik; Park, Sung Keun; Kim, Sang Yeol

    2014-11-01

    We report on a systematic study of a single-gas-electron-multiplier (GEM)-loaded gaseous detector developed for precision measurements of high-energy particle beams and for dose verification in particle therapy. In the present study, a 256-channel prototype detector having an active area of 16 × 16 cm2 and operating using a continuous current-integration-mode signal-processing method was manufactured and tested with X-rays emitted from a 70-kV X-ray generator and 43-MeV protons provided by the MC50 proton cyclotron at the Korea Institute of Radiological and Medical Science (KIRAMS). The amplified detector response was measured for X-rays with an intensity of about 5 × 106 Hz cm-2. The linearity of the detector response to the particle flux was examined and validated by using 43-MeV proton beams. The non-uniform development of the amplification for the gas electrons in space was corrected by applying a proper calibration to the channel responses of the measured beam-profile data. We conclude from the radiation tests that the detector developed in the present study will allow us to perform quality measurements of various high-energy particle beams and to apply the technology to dose-verification measurements in particle therapy.

  16. System for determining the type of nuclear radiation from detector output pulse shape

    DOEpatents

    Miller, W.H.; Berliner, R.R.

    1994-09-13

    A radiation detection system determines the type of nuclear radiation received in a detector by producing a correlation value representative of the statistical cross correlation between the shape of the detector signal and pulse shape data previously stored in memory and characteristic of respective types of radiation. The correlation value is indicative of the type of radiation. The energy of the radiation is determined from the detector signal and is used to produce a spectrum of radiation energies according to radiation type for indicating the nature of the material producing the radiation. 2 figs.

  17. Field Testing of a Portable Radiation Detector and Mapping System

    SciTech Connect

    Hofstetter, K.J. [Westinghouse Savannah River Company, AIKEN, SC (United States); Hayes, D.W.; Eakle, R.F.

    1998-03-01

    Researchers at the Savannah River Site (SRS) have developed a man- portable radiation detector and mapping system (RADMAPS) which integrates the accumulation of radiation information with precise ground locations. RADMAPS provides field personnel with the ability to detect, locate, and characterize nuclear material at a site or facility by analyzing the gamma or neutron spectra and correlating them with position. the man-portable field unit records gamma or neutron count rate information and its location, along with date and time, using an embedded Global Positioning System (GPS). RADMAPS is an advancement in data fusion, integrating several off-the-shelf technologies with new computer software resulting in a system that is simple to deploy and provides information useful to field personnel in an easily understandable form. Decisions on subsequent actions can be made in the field to efficiently use available field resources. The technologies employed in this system include: recording GPS, radiation detection (typically scintillation detectors), pulse height analysis, analog-to-digital converters, removable solid-state (Flash or SRAM) memory cards, Geographic Information System (GIS) software and personal computers with CD-ROM supporting digital base maps. RADMAPS includes several field deployable data acquisition systems designed to simultaneously record radiation and geographic positions. This paper summarizes the capabilities of RADMAPS and some of the results of field tests performed with the system.

  18. Design and construction of the prototype synchrotron radiation detector

    NASA Astrophysics Data System (ADS)

    This Paper Is Dedicated To The Memory Of Johannes `Jos'kuipers; Anderhub, H.; Bates, J. R.; Bätzner, D.; Baumgartner, S.; Biland, A.; Camps, C.; Capell, M.; Commichau, V.; Djambazov, L.; Fanchiang, Y.-J.; Flügge, G.; Fritschi, M.; Grimm, O.; Hangarter, K.; Hofer, H.; Horisberger, U.; Kan, R.; Kästli, W.; Kenney, G. P.; Kim, G. N.; Kim, K. S.; Koutsenko, V.; Kräber, M.; Kuipers, J.; Lebedev, A.; Lee, M. W.; Lee, S.-C.; Lewis, R.; Lustermann, W.; Pauss, F.; Rauber, T.; Ren, D.; Ren, Z. L.; Röser, U.; Son, D.; Ting, Samuel C. C.; Tiwari, A. N.; Viertel, G. M.; von Gunten, H.; Wicki, S. Waldmeier; Wang, T.-S.; Yang, J.; Zimmermann, B.

    2002-09-01

    The Prototype Synchrotron Radiation Detector (PSRD) is a small-scale experiment designed to measure the rate of low-energy charged particles and photons in near the Earth's orbit. It is a precursor to the Synchrotron Radiation Detector (SRD), a proposed addition to the upgraded version of the Alpha Magnetic Spectrometer (AMS-02). The SRD will use the Earth's magnetic field to identify the charge sign of electrons and positrons with energies above 1TeV by detecting the synchrotron radiation they emit in this field. The differential energy spectrum of these particles is astrophysically interesting and not well covered by the remaining components of AMS-02. Precise measurements of this spectrum offer the possibility to gain information on the acceleration mechanism and characteristics of all cosmic rays in our galactic neighbourhood. The SRD will discriminate against protons as they radiate only weakly. Both the number and energy of the synchrotron photons that the SRD needs to detect are small. The identification is complicated by the presence of a large particle and photon background. Existing measurements of these backgrounds are insufficient for the construction of the large-scale SRD, so a measurement in space was indispensable. The PSRD was designed to fly as a Space Shuttle secondary payload, within the Shuttle Small Payloads Project. The flight on board the Space Shuttle Endeavour took place from 5 to 17 December 2001. The scientific goal, hardware and the flight of the PSRD are described in this report.

  19. Design and construction of the prototype synchrotron radiation detector

    NASA Astrophysics Data System (ADS)

    Anderhub, H.; Bates, J. R.; Bätzner, D.; Baumgartner, S.; Biland, A.; Camps, C.; Capell, M.; Commichau, V.; Djambazov, L.; Fanchiang, Y.-J.; Flügge, G.; Fritschi, M.; Grimm, O.; Hangarter, K.; Hofer, H.; Horisberger, U.; Kan, R.; Kästli, W.; Kenney, G. P.; Kim, G. N.; Kim, K. S.; Koutsenko, V.; Kräber, M.; Kuipers, J.; Lebedev, A.; Lee, M. W.; Lee, S.-C.; Lewis, R.; Lustermann, W.; Pauss, F.; Rauber, T.; Ren, D.; Ren, Z. L.; Röser, U.; Son, D.; Ting, Samuel C. C.; Tiwari, A. N.; Viertel, G. M.; von Gunten, H.; Wicki, S. Waldmeier; Wang, T.-S.; Yang, J.; Zimmermann, B.; This paper is dedicated to the memory of Johannes `Jos'Kuipers

    2002-09-01

    The Prototype Synchrotron Radiation Detector (PSRD) is a small-scale experiment designed to measure the rate of low-energy charged particles and photons in near the Earth's orbit. It is a precursor to the Synchrotron Radiation Detector (SRD), a proposed addition to the upgraded version of the Alpha Magnetic Spectrometer (AMS-02). The SRD will use the Earth's magnetic field to identify the charge sign of electrons and positrons with energies above 1 TeV by detecting the synchrotron radiation they emit in this field. The differential energy spectrum of these particles is astrophysically interesting and not well covered by the remaining components of AMS-02. Precise measurements of this spectrum offer the possibility to gain information on the acceleration mechanism and characteristics of all cosmic rays in our galactic neighbourhood. The SRD will discriminate against protons as they radiate only weakly. Both the number and energy of the synchrotron photons that the SRD needs to detect are small. The identification is complicated by the presence of a large particle and photon background. Existing measurements of these backgrounds are insufficient for the construction of the large-scale SRD, so a measurement in space was indispensable. The PSRD was designed to fly as a Space Shuttle secondary payload, within the Shuttle Small Payloads Project. The flight on board the Space Shuttle Endeavour took place from 5 to 17 December 2001. The scientific goal, hardware and the flight of the PSRD are described in this report.

  20. Investigation of radiation doses in open space using TLD detectors.

    PubMed

    Reitz, G; Facius, R; Bilski, P; Olko, P

    2002-01-01

    The low energy component of the cosmic radiation field is strongly modified by the shielding of the spacecraft and it is time and location dependent. Thermoluminescent lithium fluoride detectors have been applied to determine the radiation doses inside the ESA-Facility BIOPAN. The BIOPAN facility was mounted outside and launched on a Foton spacecraft and opened to space to allow exposure of several experiments to open space. Standard TLD-600. TLD-700 chips, two layers MTS-Ns sintered pellets with different effective thickness of the sensitive layer and MTS-N of different thickness have been exposed with different shielding thicknesses in front of them. The measured TL signal in the 0.1 mm thick detector just shielded by an aluminised Kapton foil of 25 microm thickness in front yielded a dose of 29.8 Gy (calibrated with 137Cs gamma rays) for an exposure time of 12.7 days: after 2.5 g.cm(-2) shielding the doses dropped to 3 mGy. The monitoring of radiation doses and its depth dose distribution outside the spacecraft are of great interest for radiation protection of astronauts working in open space. The knowledge of depth-dose distribution is a prerequisite to determine the organ doses an astronaut will receive during an extravehicular activity (EVA). The BIOPAN experiments are to be continued in the future. PMID:12382937

  1. Examination results of the Three Mile Island radiation detector HP-R-213

    Microsoft Academic Search

    1982-01-01

    Area radiation detector HP-R-213 was removed from the Three Mile Island containment building on May 28, 1981. The detector apparently failed at the time of the hydrogen burn, and afterwards indicated radiation levels of less than 0.1mR\\/h. This report discusses the cause of failure, detector radiation measurement characteristics, and our estimates of the total gamma radiation dose received by the

  2. Examination results of the Three Mile Island radiation detector HP-R-213

    Microsoft Academic Search

    1982-01-01

    Area radiation detector HP-R-213 was removed from the Three Mile island containment building on May 28, 1981. The detector apparently failed at the time of the hydrogen burn, and afterwards indicated radiation levels of less than 0.1 mR\\/h. This report discusses the cause of failure, detector radiation measurement characteristics, and our estimates of the total gamma radiation dose received by

  3. Effect of radiation induced deep level traps on Si detector performance

    Microsoft Academic Search

    V. Eremin; E. Verbitskaya; Z. Li

    2002-01-01

    The main factor, which leads to semiconductor detector degradation in high-energy physics experiments, is the introduction of lattice defects in the detector material produced by radiation. Based on the spectrum of radiation induced defects in the silicon bulk, the overview of effects and mechanisms responsible for the changes in the main detector parameters such as effective concentration of the space

  4. Calibration of VUV spectrometer-detector system using synchrotron radiation

    SciTech Connect

    McPherson, A.; Rouze, N.; Westerveld, W.B.; Risley, J.S.

    1986-01-15

    A new technique and apparatus have been developed for the measurement of absolute electron impact photoemission cross sections in the 30--150-nm wavelength range. Synchrotron light is used as the primary intensity standard for the calibration of the detection efficiency of a vacuum ultraviolet (VUV) spectrometer-detector system. A multiadjustable manipulator was used to position precisely a Seya-Namioka-type spectrometer-detector system with respect to a narrow ray of synchrotron radiation. By scanning the beam of synchrotron radiation across the surface of the grating in the spectrometer, precise simulation of the geometry of the light source encountered in the electron impact photoemission mesurement was realized. Analysis of the results underscores the fact that for spectrometer calibrations in the VUV, the calibration procedure depends on the geometry of the experimental source. The simultaneous determination of the absolute apparatus response function of the spectrometer--detector system and the geometrical factors pertaining to the electron impact photoemission source allows photoemission cross sections in the VUV to be determined with unparalleled precision.

  5. SENTIRAD—An innovative personal radiation detector based on a scintillation detector and a silicon photomultiplier

    NASA Astrophysics Data System (ADS)

    Osovizky, A.; Ginzburg, D.; Manor, A.; Seif, R.; Ghelman, M.; Cohen-Zada, I.; Ellenbogen, M.; Bronfenmakher, V.; Pushkarsky, V.; Gonen, E.; Mazor, T.; Cohen, Y.

    2011-10-01

    The alarming personal radiation detector (PRD) is a device intended for Homeland Security (HLS) applications. This portable device is designed to be worn or carried by security personnel to detect photon-emitting radioactive materials for the purpose of crime prevention. PRD is required to meet the scope of specifications defined by various HLS standards for radiation detection. It is mandatory that the device be sensitive and simultaneously small, pocket-sized, of robust mechanical design and carriable on the user's body. To serve these specialized purposes and requirements, we developed the SENTIRAD, a new radiation detector designed to meet the performance criteria established for counterterrorist applications. SENTIRAD is the first commercially available PRD based on a CsI(Tl) scintillation crystal that is optically coupled with a silicon photomultiplier (SiPM) serving as a light sensor. The rapidly developing technology of SiPM, a multipixel semiconductor photodiode that operates in Geiger mode, has been thoroughly investigated in previous studies. This paper presents the design considerations, constraints and radiological performance relating to the SENTIRAD radiation sensor.

  6. PERDaix -Proton Electron Radiation Detector Aix-la-Chapelle

    NASA Astrophysics Data System (ADS)

    Schug, David; Schael, Stefan; Yearwood Roper, Gregorio; Bachlechner, Andreas; Beischer, Bastian; Deckenhoff, Mirco; Greim, Roman; Jenniches, Laura; Kucirek, Philipp; Lewke, Ronja; Mai, Carsten; Schug, David; Shchutska, Lesya; Tholen, Heiner; Ulrich, Jascha; Wienkenhoever, Jens; Zimmermann, Nikolas

    For the purpose of understanding recent cosmic ray measurements in the energy region below 10 GeV it is important to obtain good knowledge of the charge-sign dependent modulation caused by interplanetary magnetic fields. Existing three-dimensional time-dependent models of the heliosphere can be constrained further using series of measurements of the low-energy cosmic ray fluxes over the course of a solar cycle. Following the measurements of the positron fraction from AESOP in 2006 and 2009, we present a new light-weighted spectrometer which is under construction in Aachen for measuring helium, proton, positron and electron fluxes. The detector is designed to measure in the energy range between 0.5 GeV and 5 GeV and identify helium, protons, electrons and positrons. The detector consists of a spectrometer made up of a permanent magnet and a scintillating fiber tracking detector, a transition radiation detector and a time of flight system with a total weight of approximately 30kg. We applied successfully for a flight on a stratosphere balloon in late 2010 as part of the German-Swedish Balloon-Borne Experiments for University Students (BEXUS) Program.

  7. Radiation detector resolution over a continuous energy range

    SciTech Connect

    Zhang, Yanwen; Milbrath, Brian D.; Weber, William J.; Elfman, Mikael; Whitlow, Harry J.

    2007-08-27

    Urgent need for new radiation detector materials with excellent energy resolution at room temperature has prompted research efforts on both accelerated materials discovery and efficient techniques that can investigate candidate materials to identify material properties relevant to detector performance. In this work, an ion-beam approach is demonstrated to obtain energy resolution in both semiconductor detectors and scintillators over a continuous energy range. For semiconductors, the energy resolution of a silicon detector was measured as a function of He+ ion energy, and the values from an extrapolation to high energies are in good agreement with the literature data from alpha measurements. For the scintillators, benchmark crystals of BGO, YAP(Ce) and CsI(Tl) subject to He+ irradiation were investigated, and the corresponding energy resolution is compared with gamma-ray tests on the same crystals. The agreement of energy resolution between the ion and gamma measurements indicates that the ion approach can be used to predict energy resolution of candidate materials in thin film form (a few tens ?m thick) or a small crystals (a few mm3), when large crystals necessary for gamma-ray testing are unavailable.

  8. 3D — A proposed new architecture for solid-state radiation detectors

    Microsoft Academic Search

    S. I. Parker; C. J. Kenney; J. Segal

    1997-01-01

    A proposed new architecture for solid-state radiation detectors using a three-dimensional array of electrodes that penetrate into the detector bulk is described. Proposed fabrication steps are listed. Collection distances and calculated collection times are about one order of magnitude less than those of planar technology strip and pixel detectors with electrodes confined to the detector surface, and depletion voltages are

  9. Porous Silicon-Based Quantum Dot Broad Spectrum Radiation Detector

    PubMed Central

    Urdaneta, M.; Stepanov, P.; Weinberg, I. N.; Pala, I. R.; Brock, S.

    2013-01-01

    Silicon is a convenient and inexpensive platform for radiation detection, but has low stopping power for x-rays and gamma-rays with high energy (e.g., 100 keV, as used in computed tomography and digital radiography, or 1 MeV, as desired for detection of nuclear materials). We have effectively increased the stopping power of silicon detectors by producing a layer of porous or micro-machined silicon, and infusing this layer with semiconductor quantum dots made of electron-dense materials. Results of prototype detectors show sensitivity to infrared, visible light, and x-rays, with dark current of less than 1 nA/mm2. PMID:24432047

  10. Relaxation of radiation damages in silicon planar detectors

    SciTech Connect

    Eremin, V.; Ivanov, A.; Storkan, N.; Verbitskaya, E. [Ioffe Physico-Technial Institute, Russian Acadamey of Sciences, St. Petersburg, (Russian Federation); Li, Zheng [Brookhaven National Lab., Upton, NY (United States); Schmidt, B. [Forschungszentrum Rossendorf e.V. (FZR), Rossendorf bei Dresden (Germany)

    1993-12-01

    The behaviour of radiation induced carbon related defects in high resistivity silicon detectors has been investigated. The defects were introduced by {alpha}-particle irradiation and the measurements were carried out by the DLTS-technique. The unusual defect behaviour consists in low temperature annealing, including self annealing at room temperature, of the interstitial carbon C{sub i} with the simultaneous increase of the (C{sub i}-O{sub i})-complex concentration. The kinetic parameters of the process have been determined from the increase of the C{sub i}-centre concentration versus time. Two annealing velocities have been observed, which are due to different heat treatments during the detector fabrication process.

  11. Porous Silicon-Based Quantum Dot Broad Spectrum Radiation Detector.

    PubMed

    Urdaneta, M; Stepanov, P; Weinberg, I N; Pala, I R; Brock, S

    2011-01-11

    Silicon is a convenient and inexpensive platform for radiation detection, but has low stopping power for x-rays and gamma-rays with high energy (e.g., 100 keV, as used in computed tomography and digital radiography, or 1 MeV, as desired for detection of nuclear materials). We have effectively increased the stopping power of silicon detectors by producing a layer of porous or micro-machined silicon, and infusing this layer with semiconductor quantum dots made of electron-dense materials. Results of prototype detectors show sensitivity to infrared, visible light, and x-rays, with dark current of less than 1 nA/mm(2). PMID:24432047

  12. On the radiation tolerance of SU8, a new material for gaseous microstructure radiation detector fabrication

    Microsoft Academic Search

    M. J. Key; V. Cindro; M. Lozano

    2004-01-01

    SU-8 photosensitive epoxy resin was developed for the fabrication of high-aspect ratio microstructures in MEMS and microengineering applications, and has potential for use in the construction of novel gaseous micropattern radiation detectors. However, little is known of the behaviour of the cured material under irradiation. Mechanical properties of SU-8 film have been measured as a function of neutron exposure and

  13. A Study of an Acrylic Cerenkov Radiation Detector

    E-print Network

    B. Porter; P. Auchincloss; P. de Barbaro; A. Bodek; H. Budd

    1999-08-24

    An experiment investigating the angle of Cerenkov light emitted by 3-MeV electrons traversing an acrylic detector has been developed for use in the advanced physics laboratory course at the University of Rochester. In addition to exploring the experimental phenomena of Cerenkov radiation and total internal reflection, the experiment introduces students to several experimental techniques used in actual high energy and nuclear physics experiments, as well as to analysis techniques involving Poisson statistics. [to be published in Am. J. Phys. 67 (Oct/Nov 1999).

  14. IceCube: A Cubic Kilometer Radiation Detector

    SciTech Connect

    IceCube Collaboration; Klein, Spencer R; Klein, S.R.

    2008-06-01

    IceCube is a 1 km{sup 3} neutrino detector now being built at the Amudsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate {nu}{sub {mu}}, {nu}{sub t}, and {nu}{sub {tau}} interactions because of their different topologies. IceCube construction is currently 50% complete.

  15. Nuclear Instruments and Methods in Physics Research A 477 (2002) 299303 Radiation hard cryogenic silicon detectors

    E-print Network

    Zavrtanik, Marko

    2002-01-01

    Nuclear Instruments and Methods in Physics Research A 477 (2002) 299­303 Radiation hard cryogenic increase of the depletion voltage. When the radiation fluence approaches 1015 n=cm2 ; standard detectors the radiation hardness of silicon detectors is their operation at cryogenic temperatures. Indeed, it has been

  16. Particle identification with the ALICE transition radiation detector

    NASA Astrophysics Data System (ADS)

    Pachmayer, Yvonne

    2014-12-01

    The Transition Radiation Detector (TRD) provides particle identification in the ALICE central barrel. In particular, it allows electron identification via the measurement of transition radiation for p > 1 GeV / c, where pions can no longer be rejected sufficiently via specific energy loss in the ALICE Time Projection Chamber. The ALICE TRD is uniquely designed to record the time evolution of the signal, which allows even better electron/pion separation. In addition, the electron identification capability of the TRD can be used on-line to trigger at level 1. The particle identification and its performance in pp, p-Pb and Pb-Pb collisions employing various methods, such as truncated mean signal, one- and two-dimensional likelihood on integrated charge and neural network, will be presented. The measurement of J/? mesons in Pb-Pb collisions is given as a case study to show how well the TRD contributes to physics analyses due to its excellent pion suppression.

  17. Electrical delay line multiplexing for pulsed mode radiation detectors

    NASA Astrophysics Data System (ADS)

    Vinke, Ruud; Yeom, Jung Yeol; Levin, Craig S.

    2015-04-01

    Medical imaging systems are composed of a large number of position sensitive radiation detectors to provide high resolution imaging. For example, whole-body Positron Emission Tomography (PET) systems are typically composed of thousands of scintillation crystal elements, which are coupled to photosensors. Thus, PET systems greatly benefit from methods to reduce the number of data acquisition channels, in order to reduce the system development cost and complexity. In this paper we present an electrical delay line multiplexing scheme that can significantly reduce the number of readout channels, while preserving the signal integrity required for good time resolution performance. We experimented with two 4 × 4 LYSO crystal arrays, with crystal elements having 3 mm × 3 mm × 5 mm and 3 mm × 3 mm × 20 mm dimensions, coupled to 16 Hamamatsu MPPC S10931-050P SiPM elements. Results show that each crystal could be accurately identified, even in the presence of scintillation light sharing and inter-crystal Compton scatter among neighboring crystal elements. The multiplexing configuration degraded the coincidence timing resolution from ?243 ps FWHM to ?272 ps FWHM when 16 SiPM signals were combined into a single channel for the 4 × 4 LYSO crystal array with 3 mm × 3 mm × 20 mm crystal element dimensions, in coincidence with a 3 mm × 3 mm × 5 mm LYSO crystal pixel. The method is flexible to allow multiplexing configurations across different block detectors, and is scalable to an entire ring of detectors.

  18. Radiation Tolerance of Cryogenic Beam Loss Monitor Detectors

    E-print Network

    Kurfuerst, C; Bartosik, M; Dehning, B; Eisel, T; Sapinski, M; Eremin, V; Verbitskaya, E; Fabjan, C; Griesmayer, E

    2013-01-01

    At the triplet magnets, close to the interaction regions of the LHC, the current Beam Loss Monitoring system is sensitive to the particle showers resulting from the collision of the two beams. For the future, with beams of higher energy and intensity resulting in higher luminosity, distinguishing between these interaction products and possible quench-provoking beam losses from the primary proton beams will be challenging. Investigations are therefore underway to optimise the system by locating the beam loss detectors as close as possible to the superconducting coils of the triplet magnets. This means putting detectors inside the cold mass in superfluid helium at 1.9 K. Previous tests have shown that solid state diamond and silicon detectors as well as liquid helium ionisation chambers are promising candidates. This paper will address the final open question of their radiation resistance for 20 years of nominal LHC operation, by reporting on the results from high irradiation beam tests carried out at CERN in a...

  19. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, J.H.; Lavietes, A.D.

    1998-05-26

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector is disclosed. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radionuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components. 9 figs.

  20. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, James H. (Livermore, CA); Lavietes, Anthony D. (Hayward, CA)

    1998-05-29

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radio nuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components.

  1. Processing and characterization of epitaxial GaAs radiation detectors

    E-print Network

    Wu, X; Arsenovich, T; Gädda, A; Härkönen, J; Junkes, A; Karadzhinova, A; Kostamo, P; Lipsanen, H; Luukka, P; Mattila, M; Nenonen, S; Riekkinen, T; Tuominen, E; Winkler, A

    2015-01-01

    GaAs devices have relatively high atomic numbers (Z=31, 33) and thus extend the X-ray absorption edge beyond that of Si (Z=14) devices. In this study, radiation detectors were processed on GaAs substrates with 110 $\\mu\\textrm{m}$ - 130 $\\mu\\textrm{m}$ thick epitaxial absorption volume. Thick undoped and heavily doped p$^+$ epitaxial layers were grown using a custom-made horizontal Chloride Vapor Phase Epitaxy (CVPE) reactor, the growth rate of which was about 10 $\\mu\\textrm{m}$/h. The GaAs p$^+$/i/n$^+$ detectors were characterized by Capacitance Voltage ($CV$), Current Voltage ($IV$), Transient Current Technique (TCT) and Deep Level Transient Spectroscopy (DLTS) measurements. The full depletion voltage ($V_{\\textrm{fd}}$) of the detectors with 110 $\\mu\\textrm{m}$ epi-layer thickness is in the range of 8 V - 15 V and the leakage current density is about 10 nA/cm$^2$. The signal transit time determined by TCT is about 5 ns when the bias voltage is well above the value that produces the peak saturation drift ve...

  2. The use of synchrotron radiation for detector calibrations

    NASA Astrophysics Data System (ADS)

    Saloman, E. B.

    1980-05-01

    The National Bureau of Standards (NBS) VUV radiometric detector program calibrates photodiode detectors as radiometric transfer standards over the wavelength range between 50 and 2500 Å (5-250 eV photon energy). Our calibration uncertainty is 10% or better over this full range. The source of radiation used for calibration in the spectral region below 600 Å is synchrotron radiation from the NBS Synchrotron Ultraviolet Radiation Facility (SURF) while a duoplasmatron source is used above 600 Å. A noble gas double ionization chamber is used as the absolute detector between 400-1000 Å while a single ionization chamber is used below 400 Å and a thermopile referred to the double ionization chamber is used above 1000 Å. At wavelengths above 1200 Å magnesium flouride windowed photodiodes with cesium or rubidium telluride photocathodes serve as transfer standards. For wavelengths below 1200 Å specially prepared Al 2O 3 photodiodes are used. Their photocathodes are made by evaporating about 1800 Å of aluminum onto a quartz disc. Then a 150 Å thick layer of Al 2O 3 is formed through anodization to serve as the photoemitting surface. The properties of these diodes prove to be very sensitive to contamination especially at wavelengths below 200 Å. It is particularly important that hydrocarbon oils not be cracked on their surface since this tends to form a carbonaneous photoemitting surface. We are also investigating tungsten photocathodes as a possible transfer standard for the shorter wavelengths. In collaboration with groups at LASL and NRL studies have been made of the photoefficiency of several "practical" photocathode materials at wavelengths between 50-584 Å. Results will be shown for natural aluminum, gold, and carbon. The studies include evaluation of the stability of photoefficiency with time and the sensitivity of the photoefficiency to contamination with use in plasma machine diagnostics. In collaboration with DoE and the University of Hawaii a study was made of some high photoefficiency materials for radiometric diagnostic work. Results for CuI and CsI will be reported as will a study of some "disposable" radiometric detectors.

  3. Methodology for Assessing Radiation Detectors Used by Emergency Responders

    SciTech Connect

    Piotr Wasiolek; April Simpson

    2008-03-01

    The threat of weapons of mass destruction terrorism resulted in the U.S. Department of Homeland Security deploying large quantities of radiation detectors throughout the emergency responder community. However, emergency responders specific needs were not always met by standard health physics instrumentation used in radiation facilities. Several American National Standards Institute standards were developed and approved to evaluate the technical capabilities of detection equipment. Establishing technical capability is a critical step, but it is equally important to emergency responders that the instruments are easy to operate and can withstand the rugged situations they encounter. The System Assessment and Validation for Emergency Responders (SAVER) Program (managed by the U.S. Department of Homeland Security, Office of Grants and Training, Systems Support Division) focuses predominantly on the usability, ergonomics, readability, and other features of the detectors, rather than performance controlled by industry standards and the manufacturers. National Security Technologies, LLC, as a SAVER Technical Agent, conducts equipment evaluations using active emergency responders who are familiar with the detection equipment and knowledgeable of situations encountered in the field, which provides more relevant data to emergency responders.

  4. Experimental verification of a hand held electronically-collimated radiation detector

    Microsoft Academic Search

    W. H. Hill; Kenneth L. Matthews II

    2007-01-01

    A hand-held electronically-collimated directional detector is being developed for gamma-radiation source localization. The system comprises a 6-sided box of detectors; Compton scatter events between pairs of detectors provide the source localization data. We report on experimental and simulation results for a partial prototype, with extrapolation to potential performance of a full detector system. The partial prototype used CZT detector modules

  5. Single charge carrier type sensing with a parallel strip pseudo-Frisch-grid CdZnTe semiconductor radiation detector

    E-print Network

    He, Zhong

    radiation detector D. S. McGregor,a) Z. He, H. A. Seifert, and D. K. Wehe Department of Nuclear Engineering temperature operated ra- diation detectors. The most common semiconductor radiation detector design CdZnTe semiconductor detector that incorporates a parallel strip pseudo-Frisch-grid detector design

  6. Characteristics of VPE GaAs radiation detectors after proton irradiation

    E-print Network

    Glasgow, University of

    Characteristics of VPE GaAs radiation detectors after proton irradiation Craig Whitehill Dept.2 The Radiation Environment . . . . . . . . . . . . . . . . . . . 8 1.3 Choice of GaAs . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.4 Thesis Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2 Semiconductor Theory

  7. Use of radiation detectors in remote monitoring for containment and surveillance

    SciTech Connect

    Dupree, S.A.; Ross, M. [Sandia National Labs., Albuquerque, NM (United States); Bonino, A. [Nuclear Regulatory Authority of Argentina, Buenos Aires (Argentina); Lucero, R.; Hasimoto, Yu [PNC Oarai Engineering Center, Ibaraki (Japan)

    1998-07-01

    Radiation detectors have been included in several remote monitoring field trial systems to date. The present study considers detectors at Embalse, Argentina, and Oarai, Japan. At Embalse four gamma detectors have been operating in the instrumentation tubes of spent fuel storage silos for up to three years. Except for minor fluctuations, three of the detectors have operated normally. One of the detectors appears never to have operated correctly. At Oarai two gamma detectors have been monitoring a spent-fuel transfer hatch for over 18 months. These detectors have operated normally throughout the period, although one shows occasional noise spikes.

  8. Field Deployable Gamma Radiation Detectors for DHS Use

    SciTech Connect

    Sanjoy Mukhopadhyay

    2007-08-31

    Recently, the U.S. Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS’s requirements in terms of sensitivity, resolution, response time and reach back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron’s identiFINDER™, which primarily uses sodium iodide crystals (3.18-cm x 2.54-cm cylinders) as gamma detector, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack™ that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity (comparable to that of a 7.62-cm x 7.62-cm sodium iodide crystal at low gamma energy ranging from 30 keV to 3,000 keV), better resolution (< 3.0 percent at 662 keV), faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system auto triggers saving of relevant spectral data and software-triggers the digital camera to take a snapshot. The spectral data including in situ analysis and the imagery data will be packaged in a suitable format and sent to a command post using an imbedded cell phone.

  9. Radiation resistance of wide-gap materials as exemplified by SiC nuclear radiation detectors

    NASA Astrophysics Data System (ADS)

    Ivanov, A. M.; Strokan, N. B.; Lebedev, A. A.

    2012-04-01

    In wide-gap materials used in nuclear detectors, the polarization effect is typically observed when the concentration of radiation-induced defects is high. An emf arising in the detector is associated with long-term trapping of charge carries by deep radiation-induced levels (centers). The polarization kinetics and the polarization field strength are determined experimentally. The trapping efficiency can be controlled by varying the temperature, and a tradeoff can be reached at an "optimal" temperature between the generation current and the position of the deepest level, which has a negligible effect on charge losses via trapping. It is found that the ratio between the depth of this level and the bandgap is about 1/3 irrespective of the material but the optimal temperature is material-specific.

  10. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOEpatents

    Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

    1996-10-22

    An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

  11. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOEpatents

    Majewski, Stanislaw (Grafton, VA); Kross, Brian J. (Yorktown, VA); Zorn, Carl J. (Yorktown, VA); Majewski, Lukasz A. (Grafton, VA)

    1996-01-01

    An optimized examination system and method based on the Reverse Geometry X-Ray.RTM. (RGX.RTM.) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging.

  12. Space radiation dosimetry: An optically stimulated luminescence radiation detector for low-Earth orbit

    Microsoft Academic Search

    Ramona Gaza

    2004-01-01

    Scope and method of study. The purpose of this study was to investigate Al2O3:C as a potential optically stimulated luminescence (OSL) radiation detector for Low-Earth Orbit. The OSL response of Al2O3:C was characterized in terms of its luminescence efficiency for a variety of heavy charged particles (HCPs) with features similar to those found in space. The HCP irradiations were performed

  13. Personal Radiation Detector Field Test and Evaluation Campaign

    SciTech Connect

    Chris A. Hodge, Ding Yuan, Raymond P. Keegan, Michael A. Krstich

    2007-07-09

    Following the success of the Anole test of portable detection system, the U.S. Department of Homeland Security (DHS) Domestic Nuclear Detection Office organized a test and evaluation campaign for personal radiation detectors (PRDs), also known as 'Pagers'. This test, 'Bobcat', was conducted from July 17 to August 8, 2006, at the Nevada Test Site. The Bobcat test was designed to evaluate the performance of PRDs under various operational scenarios, such as pedestrian surveying, mobile surveying, cargo container screening, and pedestrian chokepoint monitoring. Under these testing scenarios, many operational characteristics of the PRDs, such as gamma and neutron sensitivities, positive detection and false alarm rates, response delay times, minimum detectable activities, and source localization errors, were analyzed. This paper will present the design, execution, and methodologies used to test this equipment for the DHS.

  14. Combined performance tests before installation of the ATLAS Semiconductor and Transition Radiation Tracking Detectors

    Microsoft Academic Search

    E Abat; A Abdesselam; T N Addy; T P A Åkesson; P P Allport; L Andricek; F Anghinolfi; R Apsimon; E Arik; M Arik; N Austin; O K Baker; E Banas; A Bangert; G Barbier; S Baron; A J Barr; S Basiladze; L E Batchelor; R L Bates; J R Batley; M Battistin; G A Beck; A Beddall; P J Bell; W H Bell; A Belymam; D P Benjamin; J Bernabeu; H Bertelsen; S Bethke; A Bingul; A Bitadze; J P Bizzell; J Blocki; A Bocci; M Bochenek; J Bohm; V G Bondarenko; P Bonneau; C N Booth; O Brandt; F M Brochu; Z Broklova; J Broz; P A Bruckman de Renstrom; S Burdin; C M Buttar; M Capeáns Garrido; L Cardiel Sas; C Carpentieri; A A Carter; J R Carter; A Catinaccio; S A Cetin; M Chamizo llatas; D G Charlton; A Cheplakov; S Chouridou; M L Chu; V Cindro; A Ciocio; J V Civera; A Clark; A P Colijn; T Cornelissen; M J Costa; D Costanzo; J Cox; P Cwetanski; W Dabrowski; J Dalmau; M Dam; K M Danielsen; H Danielsson; S DAuria; I Dawson; P de Jong; M D Dehchar; B Demirkoz; P Dervan; B Di Girolamo; S Diez Cornell; F Dittus; S D Dixon; E Dobson; O B Dogan; Z Dolezal; B A Dolgoshein; M Donega; M DOnofrio; T Donszelmann; O Dorholt; J D Dowell; Z Drasal; N Dressnandt; C Driouchi; R Duxfield; M Dwuznik; W L Ebenstein; S Eckert; P Eerola; U Egede; K Egorov; L M Eklund; M Elsing; R Ely; V Eremin; C Escobar; H Evans; P Farthouat; D Fasching; O L Fedin; L Feld; D Ferguson; P Ferrari; D Ferrere; L Fiorini; J Fopma; A J Fowler; H Fox; R S French; D Froidevaux; J A Frost; J Fuster; S Gadomski; P Gagnon; B J Gallop; F C Gannaway; C Garcia; J E Garcia Navarro; I L Gavrilenko; C Gay; N Ghodbane; M D Gibson; S M Gibson; K G Gnanvo; J Godlewski; T Göttfert; S Gonzalez; S Gonzalez-Sevilla; M J Goodrick; A Gorišek; E Gornicki; M Goulette; Y Grishkevich; J Grognuz; J Grosse-Knetter; C Haber; R Härtel; Z Hajduk; M Hance; F H Hansen; J B Hansen; J D Hansen; P H Hansen; K Hara; A Harvey Jr; M Hauschild; C Hauviller; B M Hawes; R J Hawkings; H S Hayward; S J Haywood; F E W Heinemann; N P Hessey; J C Hill; M C Hodgkinson; P Hodgson; T I Hollins; A Holmes; R Holt; S Hou; D F Howell; W Hulsbergen; T Huse; Y Ikegami; Y Ilyushenka; C Issever; J N Jackson; V Jain; K Jakobs; R C Jared; G Jarlskog; P Jarron; L G Johansen; P Johansson; M Jones; T J Jones; D Joos; J Joseph; P Jovanovic; V A Kantserov; J Kaplon; M Karagoz Unel; F Kayumov; P T Keener; G D Kekelidze; N Kerschen; C Ketterer; S H Kim; D Kisielewska; B Kisielewski; T Kittelmann; E B Klinkby; P Kluit; S Kluth; B R Ko; P Kodys; T Koffas; E Koffeman; T Kohriki; T Kondo; N V Kondratieva; S P Konovalov; S Koperny; H Korsmo; S Kovalenko; T Z Kowalski; K Krüger; V Kramarenko; G Kramberger; M Kruse; P Kubik; L G Kudin; N Kundu; C Lacasta; V R Lacuesta; W Lau; A-C Le Bihan; S-C Lee; R P Lefevre; B C LeGeyt; K J C Leney; C G Lester; Z Liang; P Lichard; W Liebig; M Limper; A Lindahl; S W Lindsay; A Lipniacka; G Llosa Llacer; S Lloyd; A Loginov; C W Loh; M Lozano Fantoba; S Lucas; A Lucotte; I Ludwig; J Ludwig; F Luehring; L Luisa; J Lynn; M Maaßen; D Macina; R Mackeprang; A Macpherson; C A Magrath; P Majewski; P Malecki; V P Maleev; I Mandi?; M Mandl; M Mangin-Brinet; S Marti i Garcia; A J Martin; F F Martin; T Maruyama; R Mashinistov; A Mayne; K W McFarlane; S J McMahon; T J McMahon; J Meinhardt; B R Mellado Garcia; C Menot; I Messmer; B Mikulec; M Mikuž; S Mima; M Minano; B Mindur; V A Mitsou; P Modesto; S Moed; B Mohn; R M Moles Valls; J Morin; M-C Morone; S V Morozov; J Morris; H G Moser; A Moszczynski; S V Mouraviev; A Munar; W J Murray; K Nagai; Y Nagai; D Naito; K Nakamura; I Nakano; S Y Nesterov; F M Newcomer; R Nicholson; R B Nickerson; T Niinikoski; N Nikitin; R Nisius; H Ogren; S H Oh; M Olcese; J Olszowska; M Orphanides; V OShea; W Ostrowicz; B Ottewell; O Oye; E Paganis; M J Palmer; M A Parker; U Parzefall; M S Passmore; S Pataraia; G Pellegrini; H Pernegger; E Perrin; V D Peshekhonov; T C Petersen; R Petti; A W Phillips; P W Phillips; A Placci; K Poltorak; A Poppleton; M J Price; K Prokofiev; O Røhne; C Rembser; P Reznicek; R H Richter; A Robichaud-Veronneau; D Robinson; S Roe; O Rohne; A Romaniouk; L P Rossi; D Rousseau; G Ruggiero; K Runge; Y F Ryabov; A Salzburger; J Sanchez; H Sandaker; J Santander; V A Schegelsky; D Scheirich; J Schieck; M P Schmidt; C Schmitt; E Sedykh; D M Seliverstov; A Sfyrla; T Shin; A Shmeleva; S Sivoklokov; S Yu Smirnov; L Smirnova; O Smirnova; M Söderberg; A O Solberg; V V Sosnovtsev; L Sospedra Suay; H Spieler; G Sprachmann; E Stanecka; S Stapnes; J Stastny; M Stodulski; A Stradling; B Stugu; S Subramania; S I Suchkov; V V Sulin; R R Szczygiel; R Takashima; R Tanaka; G Tartarelli; P K Teng; S Terada; V O Tikhomirov; P Tipton; M Titov; K Toms; A Tonoyan; D R Tovey; A Tricoli; M Turala; M Tyndel; F Ukegawa; M Ullan Comes; Y Unno; V Vacek; S Valkar; J A Valls Ferrer; E van der Kraaij; R VanBerg; V I Vassilakopoulos; L Vassilieva; T Vickey; G H A Viehhauser; E G Villani; J H Vossebeld; T Vu Anh; R Wall; R S Wallny

    2008-01-01

    The ATLAS (A Toroidal LHC ApparatuS) Inner Detector provides charged particle tracking in the centre of the ATLAS experiment at the Large Hadron Collider (LHC). The Inner Detector consists of three subdetectors: the Pixel Detector, the Semiconductor Tracker (SCT), and the Transition Radiation Tracker (TRT). This paper summarizes the tests that were carried out at the final stage of SCT+TRT

  15. Study of multi-electrodes structure in CdTe nuclear radiation detectors

    Microsoft Academic Search

    Madan Niraula; Yasunori Agata; Kazuhito Yasuda

    2004-01-01

    We studied CdTe nuclear radiation detectors with multi-electrodes structure. The detector consists of a common cathode, while the anode has been separated into three electrodes: the central collecting anode, a guard ring electrode, and a guiding electrode. The detector was biased in such a way that the central anode collects electrons while the guiding electrode repel electrons and guide them

  16. AN EVALUATION OF CADMIUM SULFIDE AS A NUCLEAR RADIATION DETECTOR (thesis)

    Microsoft Academic Search

    1962-01-01

    Solid state radiation detectors were constructed using crystal platelets ; of CdS. Both intrinsic and p-n junction detectors were made and evaluated. ; Although alpha particles were detected by both types of detectors, the mobility-; lifetime product of the charge carriers resulted in the pulse response not being ; proportional to the energy of the incident particle. The best experimental

  17. Charge-trap correction and radiation damage in orthogonal-strip planar germanium detectors

    NASA Astrophysics Data System (ADS)

    Hull, E. L.; Jackson, E. G.; Lister, C. J.; Pehl, R. H.

    2014-10-01

    A charge-carrier trap correction technique was developed for orthogonal strip planar germanium gamma-ray detectors. The trap corrector significantly improves the gamma-ray energy resolution of detectors with charge-carrier trapping from crystal-growth defects and radiation damage. Two orthogonal-strip planar germanium detectors were radiation damaged with 2-MeV neutron fluences of ~8×109 n/cm2. The radiation-damaged detectors were studied in the 60-80 K temperature range.

  18. Seismic restraint means for a nuclear radiation detector mounted in a tubular thimble

    Microsoft Academic Search

    R. H. Underwood; W. H. Todt

    1985-01-01

    Seismic restraint means are provided for mounting an elongated, generally cylindrical nuclear radiation detector within a tubular thimble. The restraint means permits longitudinal movement of the restraint means and the radiation detector into and out of the thimble. The restraint means includes spring bias means and thimble constant means whereby the contact means engage the thimble with a constant predetermined

  19. Testing and Evaluation Protocol for Alarming Personal Radiation Detectors for Homeland Security

    E-print Network

    Testing and Evaluation Protocol for Alarming Personal Radiation Detectors for Homeland Security T Radiation Detectors for Homeland Security EFF. DATE 2013-05-17 REV. 3.00 PAGE 1 of 5 Testing and Evaluation................................................................................1 4. Test and evaluation steps

  20. Testing and Evaluation Protocol for Alarming Personal Radiation Detectors for Homeland Security

    E-print Network

    Perkins, Richard A.

    Testing and Evaluation Protocol for Alarming Personal Radiation Detectors for Homeland Security T .........................................................................................................3 #12;TEST AND EVALUATION PROTOCOL TEP NO. N42.32 PREPARED BY: DIV682 TITLE: Alarming Personal Radiation Detectors for Homeland Security EFF. DATE 2010-11-09 REV. 2.02 PAGE 1 of 74 Testing and Evaluation

  1. Particle Identification with the ALICE Transition Radiation Detector

    E-print Network

    Pachmayer, Yvonne

    2014-01-01

    The Transition Radiation Detector (TRD) provides particle identification in the ALICE central barrel. In particular, it allows electron identification via the measurement of transition radiation for $\\rm p >$ 1 GeV/$c$, where pions can no longer be rejected sufficiently via specific energy loss in the ALICE Time Projection Chamber. The ALICE TRD is uniquely designed to record the time evolution of the signal, which allows even better electron/pion separation. In addition, the electron identification capability of the TRD can be used on-line to trigger at level 1. The particle identification and its performance in pp, p-Pb and Pb-Pb collisions employing various methods, such as truncated mean signal, one- and two-dimensional likelihood on integrated charge and neural network, will be presented. The measurement of J/$\\psi$ mesons in Pb-Pb collisions is given as a case study to show how well the TRD contributes to physics analyses due to its excellent pion suppression.

  2. Particle Identification with the ALICE Transition Radiation Detector

    E-print Network

    Yvonne Pachmayer for the ALICE Collaboration

    2014-02-14

    The Transition Radiation Detector (TRD) provides particle identification in the ALICE central barrel. In particular, it allows electron identification via the measurement of transition radiation for $\\rm p >$ 1 GeV/$c$, where pions can no longer be rejected sufficiently via specific energy loss in the ALICE Time Projection Chamber. The ALICE TRD is uniquely designed to record the time evolution of the signal, which allows even better electron/pion separation. In addition, the electron identification capability of the TRD can be used on-line to trigger at level 1. The particle identification and its performance in pp, p-Pb and Pb-Pb collisions employing various methods, such as truncated mean signal, one- and two-dimensional likelihood on integrated charge and neural network, will be presented. The measurement of J/$\\psi$ mesons in Pb-Pb collisions is given as a case study to show how well the TRD contributes to physics analyses due to its excellent pion suppression.

  3. Wire-chamber radiation detector with discharge control

    DOEpatents

    Perez-Mendez, V.; Mulera, T.A.

    1982-03-29

    A wire chamber; radiation detector has spaced apart parallel electrodes and grids defining an ignition region in which charged particles or other ionizing radiations initiate brief localized avalanche discharges and defining an adjacent memory region in which sustained glow discharges are initiated by the primary discharges. Conductors of the grids at each side of the memory section extend in orthogonal directions enabling readout of the X-Y coordinates of locations at which charged particles were detected by sequentially transmitting pulses to the conductors of one grid while detecting transmissions of the pulses to the orthogonal conductors of the other grid through glow discharges. One of the grids bounding the memory region is defined by an array of conductive elements each of which is connected to the associated readout conductor through a separate resistance. The wire chamber avoids ambiguities and imprecisions in the readout of coordinates when large numbers of simultaneous or; near simultaneous charged particles have been detected. Down time between detection periods and the generation of radio frequency noise are also reduced.

  4. Development of CdTe nuclear radiation detectors for spectroscopy and imaging applications

    Microsoft Academic Search

    M. Niraula; K. Yasuda; Y. Agata; A. Nakamura; T. Aoki; Y. Hatanaka

    2003-01-01

    CdTe nuclear radiation detectors were developed for spectroscopy and imaging applications. Detectors were fabricated in two different techniques in order to alleviate the poor hole charge transport property in CdTe semiconductor. The first type comprises an M-?-n diode type detector fabricated by growing an n-type CdTe epitaxial layer on the p-like high resistivity CdTe crystal wafer. This detector is operated

  5. SEMICONDUCTOR NUCLEAR-RADIATION DETECTORS. SILICON JUNCTION DETECTORS OF GOOD RESOLUTION, LONG-TERM STABILITY AND FAST RISE TIME SUITABLE FOR NUCLEAR RESEARCH

    Microsoft Academic Search

    J. Terada; Y. Ebara; J. Yoshida; T. Kobayashi

    1963-01-01

    Characteristics of the silicon junction detector and some examples of ; its applications to radiation detection are described. The range of effective ; detection was improved and its application to BETA and gamma measurements was ; expanded. Work was carried out toward the development of a series of radiation ; detectors including a lithium-ion drifted silicon (germanium) detector. (auth);

  6. Effect of a metal electrode on the radiation tolerance of a SiC neutron detector

    NASA Astrophysics Data System (ADS)

    Park, Junesic; Shin, Hee-Sung; Kim, Ho-Dong; Kim, Han Soo; Park, Se Hwan; Lee, Cheol Ho; Kim, Yong Kyun

    2012-08-01

    The Korea Atomic Energy Research Institute (KAERI) has developed a silicon carbide (SiC) diode as a neutron detector that can be used in harsh environments such as nuclear reactor cores and spent fuel. The radiation tolerance of the SiC detector was studied in the present work. Especially, the effect of a metal electrode on the radiation tolerance of the SiC detector was studied. Four different types of SiC detectors were fabricated, and the operation properties of the detectors were measured and compared before and after neutron irradiations of 2.16 × 1015 n/cm2 and 5.40 × 1017 n/cm2. From the comparison, the detector with a Ti/Au electrode structure showed the highest radiation tolerance among detectors. A detector assembly was fabricated using two types of SiC p-i-n diode detectors: one containing 6LiF and the other without it. Signals from the detectors were measured in the current mode to minimize the noise of the detector. Signal currents from detectors were measured for neutron fluxes ranging from 5.54 × 106 n/cm2 s to 2.86 × 108 n/cm2 s and gamma doses up to 100 Gy/h.

  7. Signal and noise analysis of aSi:H radiation detector-amplifier system

    Microsoft Academic Search

    Gyuseong Cho; Gyuseong

    1992-01-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1-d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same

  8. Radiation damage effects by 25 MeV protons and thermal annealing effects on thallium bromide nuclear radiation detectors

    Microsoft Academic Search

    K. Hitomi; T. Shoji; T. Suehiro; Y. Hiratate

    1999-01-01

    In this study, TlBr detectors were irradiated with 25 MeV protons accelerated by an AVF cyclotron. Isothermal annealing was performed to restore the performance of the detectors. In order to characterize the radiation damage and thermal annealing effects on the TlBr detectors, we measured current-voltage (I-V) characteristics, mobility-lifetime (??) products and spectrometric responses. The I-V and ?? measurements suggest that

  9. Plural-wavelength flame detector that discriminates between direct and reflected radiation

    NASA Technical Reports Server (NTRS)

    Hall, Gregory H. (Inventor); Barnes, Heidi L. (Inventor); Medelius, Pedro J. (Inventor); Simpson, Howard J. (Inventor); Smith, Harvey S. (Inventor)

    1997-01-01

    A flame detector employs a plurality of wavelength selective radiation detectors and a digital signal processor programmed to analyze each of the detector signals, and determine whether radiation is received directly from a small flame source that warrants generation of an alarm. The processor's algorithm employs a normalized cross-correlation analysis of the detector signals to discriminate between radiation received directly from a flame and radiation received from a reflection of a flame to insure that reflections will not trigger an alarm. In addition, the algorithm employs a Fast Fourier Transform (FFT) frequency spectrum analysis of one of the detector signals to discriminate between flames of different sizes. In a specific application, the detector incorporates two infrared (IR) detectors and one ultraviolet (UV) detector for discriminating between a directly sensed small hydrogen flame, and reflections from a large hydrogen flame. The signals generated by each of the detectors are sampled and digitized for analysis by the digital signal processor, preferably 250 times a second. A sliding time window of approximately 30 seconds of detector data is created using FIFO memories.

  10. Proceedings of ICRC 2001: 2223 c Copernicus Gesellschaft 2001 The Transition Radiation Detector for the PAMELA experiment

    E-print Network

    Morselli, Aldo

    Radiation Detector (TRD) has been developed and tested for the PAMELA instrument. PAMELA is a satellite (Adriani et al., 1999), a transition radiation detector (TRD), a silicon- tungsten imaging calorimeter view of a 32 straws module. 2 The Transition Radiation Detector The PAMELA TRD will be placed on top

  11. A liquid radiation detector with high spatial resolution

    NASA Technical Reports Server (NTRS)

    Alvarez, L.

    1972-01-01

    Detector, using point anode, minimizes problem of oblique tracks by permitting construction of very thin counter. Detector is useful in cosmic ray and high energy physics research and X-ray and neutron diffraction technology.

  12. Accelerated Detector - Quantum Field Correlations: From Vacuum Fluctuations to Radiation Flux

    E-print Network

    Shih-Yuin Lin; B. L. Hu

    2006-06-21

    In this paper we analyze the interaction of a uniformly accelerated detector with a quantum field in (3+1)D spacetime, aiming at the issue of how kinematics can render vacuum fluctuations the appearance of thermal radiance in the detector (Unruh effect) and how they engender flux of radiation for observers afar. Two basic questions are addressed in this study: a) How are vacuum fluctuations related to the emitted radiation? b) Is there emitted radiation with energy flux in the Unruh effect? We adopt a method which places the detector and the field on an equal footing and derive the two-point correlation functions of the detector and of the field separately with full account of their interplay. From the exact solutions, we are able to study the complete process from the initial transient to the final steady state, keeping track of all activities they engage in and the physical effects manifested. We derive a quantum radiation formula for a Minkowski observer. We find that there does exist a positive radiated power of quantum nature emitted by the detector, with a hint of certain features of the Unruh effect. We further verify that the total energy of the dressed detector and a part of the radiated energy from the detector is conserved. However, this part of the radiation ceases in steady state. So the hint of the Unruh effect in radiated power is actually not directly from the energy flux that the detector experiences in Unruh effect. Since all the relevant quantum and statistical information about the detector (atom) and the field can be obtained from the results presented here, they are expected to be useful, when appropriately generalized, for addressing issues of quantum information processing in atomic and optical systems, such as quantum decoherence, entanglement and teleportation.

  13. Charged Particle Induced Radiation damage of Germanium Detectors in Space: Two Mars Observer Gamma-Ray Detectors

    NASA Technical Reports Server (NTRS)

    Bruekner, J.; Koenen, M.; Evans, L. G.; Starr, R.; Bailey, S. H.; Boynton W. V.

    1997-01-01

    The Mars Observer Gamma-Ray Spectrometer (MO GRS) was designed to measure gamma-rays emitted by the Martian surface. This gamma-ray emission is induced by energetic cosmic-ray particles penetrating the Martian surface and producing many secondary particles and gamma rays. The MO GRS consisted of an high-purity germanium (HPGe) detector with a passive cooler. Since radiation damage due to permanent bombardment of energetic cosmic ray particles (with energies up to several GeV) was expected for the MO GRS HPGe crystal, studies on radiation damage effects of HPGe crystals were carried on earth. One of the HPGe crystals (paradoxically called FLIGHT) was similar to the MO GRS crystal. Both detectors, MO GRS and FLIGHT, contained closed-end coaxial n-type HPGe crystals and had the same geometrical dimensions (5.6 x 5.6 cm). Many other parameters, such as HV and operation temperature, differed in space and on earth, which made it somewhat difficult to directly compare the performance of both detector systems. But among other detectors, detector FLIGHT provided many useful data to better understand radiation damage effects.

  14. Dynamic Electrothermal Model of a Sputtered Thermopile Thermal Radiation Detector for Earth Radiation Budget Applications

    NASA Technical Reports Server (NTRS)

    Weckmann, Stephanie

    1997-01-01

    The Clouds and the Earth's Radiant Energy System (CERES) is a program sponsored by the National Aeronautics and Space Administration (NASA) aimed at evaluating the global energy balance. Current scanning radiometers used for CERES consist of thin-film thermistor bolometers viewing the Earth through a Cassegrain telescope. The Thermal Radiation Group, a laboratory in the Department of Mechanical Engineering at Virginia Polytechnic Institute and State University, is currently studying a new sensor concept to replace the current bolometer: a thermopile thermal radiation detector. This next-generation detector would consist of a thermal sensor array made of thermocouple junction pairs, or thermopiles. The objective of the current research is to perform a thermal analysis of the thermopile. Numerical thermal models are particularly suited to solve problems for which temperature is the dominant mechanism of the operation of the device (through the thermoelectric effect), as well as for complex geometries composed of numerous different materials. Feasibility and design specifications are studied by developing a dynamic electrothermal model of the thermopile using the finite element method. A commercial finite element-modeling package, ALGOR, is used.

  15. Status of radiation damage measurements in room temperature semiconductor radiation detectors

    SciTech Connect

    Franks, L.A.; James, R.B.

    1998-04-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI{sub 2}) is reviewed for the purpose of determining their applicability to space applications. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10{sup 10} p/cm{sup 2} and significant bulk leakage after 10{sup 12} p/cm{sup 2}. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 {times} 10{sup 9} p/cm{sup 2} in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum neutrons after fluences up to 10{sup 10} n/cm{sup 2}, although activation was evident. CT detectors show resolution losses after fluences of 3 {times} 10{sup 9} p/cm{sup 2} at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 {times} 10{sup 10} n/cm{sup 2}. Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10{sup 12} p/cm{sup 2} and with 1.5 GeV protons at fluences up to 1.2 {times} 10{sup 8} p/cm{sup 2}. Neutron exposures at 8 MeV have been reported at fluences up to 10{sup 15} n/cm{sup 2}. No radiation damage was found under these irradiation conditions.

  16. X-Ray Detector: An x-ray radiation detector design code

    Microsoft Academic Search

    Rick B. Spielman

    1990-01-01

    X-Ray Detector (XRD) is an x-ray detector design code. It is intended to aid in the rapid design of x-ray detector packages. The design capabilities of XRD include filters, x-ray mirrors, x-ray diodes, silicon PIN diodes, GaAs PIN diodes, photoconducting detectors, bolometers, and x-ray film. XRD uses x-ray cross-section information stored in easily-modified external libraries. Interactive calculations are completed in

  17. Recent Progress in CERN RD39: Radiation Hard Cryogenic Silicon Detectors for Applications in LHC Experiments and Their Future Upgrades

    Microsoft Academic Search

    E. Tuominen; P. Anbinderis; T. Anbinderis; R. Bates; W. de Boer; E. Borchi; M. Bruzzi; C. Buttar; W. Chen; V. Cindro; S. Czellar; A. Dierlamm; V. Eremin; E. Gaubas; J. Harkonen; E. Heijne; I. Ilyashenko; V. Kalesinskas; M. J. Kortelainen; T. Lampen; Z. Li; P. Luukka; I. Mandic; D. Menichelli; M. Mikuz; O. Militaru; S. Mueller; T. Maenpaa; T. O. Niinikoski; V. O'Shea; C. Parkes; K. Piotrzkowski; S. Pirollo; P. Pusa; J. Raisanen; E. Tuovinen; J. Vaitkus; E. Verbitskaya; S. Vayrynen; M. Zavrtanik

    2009-01-01

    CERN RD39 Collaboration develops radiation-hard cryogenic silicon detectors. Recently, we have demonstrated improved radiation hardness in novel Current Injected Detectors (CID). For detector characterization, we have applied cryogenic Transient Current Technique (C-TCT). In beam tests, heavily irradiated CID detector showed capability for particle detection. Our results show that the CID detectors are operational at the temperature -50degC after the fluence

  18. Recent progress in CERN RD39 Radiation hard cryogenic silicon detectors for applications in LHC experiments and their future upgrades

    E-print Network

    Tuominen, E; Anbinderis, T; Bates, R; de Boer, W; Borchi, E; Bruzzi, M; Buttar, C; Chen, W; Cindro, V; Czellar, S; Dierlamm, A; Eremin, V; Gaubas, E; Härkönen, J; Heijne, E; Ilyashenko, I; Kalesinskas, V; Kortelainen, M J; Lampen, T; Li, Z; Luukka, P; Mandic, I; Menichelli, D; Mikuz, M; Militaru, O; Mueller, S; Mäenpää, T; Niinikoski, T O; O'Shea, V; Parkes, C; Piotrzkowski, K; Pirollo, S; Pusa, P; Räisänen, J; Tuovinen, E.; Vaitkus, J; Verbitskaya, E; Väyrynen, S; Zavrtanik, M; 10.1109/TNS.2009.2013950

    2009-01-01

    CERN RD39 Collaboration develops radiation-hard cryogenic silicon detectors. Recently, we have demonstrated improved radiation hardness in novel Current Injected Detectors (CID). For detector characterization, we have applied cryogenic Transient Current Technique (C-TCT). In beam tests, heavily irradiated CID detector showed capability for particle detection. Our results show that the CID detectors are operational at the temperature -50degC after the fluence of 1 times 1016 1 MeV neutron equivalent/cm2.

  19. Recent progress in CERN RD39: radiation hard cryogenic silicon detectors for applications in LHC experiments and their future upgrades

    Microsoft Academic Search

    E. Tuominen; P. Anbinderis; T. Anbinderis; R. Bates; W. de Boer; E. Borchi; M. Bruzzi; C. Buttar; W. Chen; V. Cindro; S. Czellar; V. Eremin; A. Furgeri; E. Gaubas; J. Harkonen; E. Heijne; I. Ilyashenko; V. Kalesinskas; M. J. Kortelainen; M. Krause; T. Lampen; Z. Li; P. Luukka; I. Mandic; D. Menichelli; M. Mikuz; O. Militaru; S. Mueller; T. Maenpaa; T. O. Niinikoski; V. O'Shea; C. Parkes; K. Piotrzkowski; S. Pirollo; P. Pusa; J. Raisanen; X. Rouby; E. Tuovinen; J. Vaitkus; E. Verbitskaya; S. Vayrynen; M. Zavrtanik

    2008-01-01

    CERN RD39 Collaboration develops radiation-hard cryogenic silicon detectors. Recently, we have demonstrated improved radiation hardness in novel Current Injected Detectors (CID). For detector characterization, we have applied cryogenic Transient Current Technique (C-TCT). In beam tests, heavily irradiated CID detector showed capability for particle detection. Our results show that the CID detectors are operational at the temperature -50°C after 1016 1

  20. Crystallographic and metallurgical characterization of radiation detector grade cadmium telluride materials

    SciTech Connect

    Johnson, C.J.; Eissler, E.E.; Cameron, S.E. (II-VI, Inc., Saxonburg, PA (United States). eV Products Div.); Kong, Y.; Fan, S.; Jovanovic, S.; Lynn, K.G. (Brookhaven National Lab., Upton, NY (United States))

    1993-01-01

    Radiation detector grade CdTe crystals are characterized by several crystallographic and metallurgical techniques including infrared microscopy, dislocation etch pitting and X-ray diffraction. Results are presented for a set of 50 detectors fabricated from an ingot produced by the High Pressure Bridgman method. Data on the temperature dependence of leakage current and pulse height analysis are presented, along with measurements of room temperature charge transport properties. Attempts to relate crystal structure to detector performance discussed.

  1. Crystallographic and metallurgical characterization of radiation detector grade cadmium telluride materials

    SciTech Connect

    Johnson, C.J.; Eissler, E.E.; Cameron, S.E. [II-VI, Inc., Saxonburg, PA (United States). eV Products Div.; Kong, Y.; Fan, S.; Jovanovic, S.; Lynn, K.G. [Brookhaven National Lab., Upton, NY (United States)

    1993-06-01

    Radiation detector grade CdTe crystals are characterized by several crystallographic and metallurgical techniques including infrared microscopy, dislocation etch pitting and X-ray diffraction. Results are presented for a set of 50 detectors fabricated from an ingot produced by the High Pressure Bridgman method. Data on the temperature dependence of leakage current and pulse height analysis are presented, along with measurements of room temperature charge transport properties. Attempts to relate crystal structure to detector performance discussed.

  2. The design and application of lithium drift silicon diodes as nuclear radiation detectors

    Microsoft Academic Search

    P. E. Gibbons; N. G. Blamires

    1965-01-01

    A range of lithium-drifted silicon radiation detectors is described. Areas up to 8 cm2 and thicknesses up to 0.6 cm have been achieved. At - 20°C, a resolution of 8 kev full width half maximum was obtained on 661 kev beta particles using a 1 cm2 detector 0.1 cm thick. The performance of the detectors is discussed in relation to

  3. CdZnTe semiconductor parallel strip Frisch grid radiation detectors

    Microsoft Academic Search

    D. S. McGregor; Z. He; H. A. Seifert; R. A. Rojeski; D. K. Wehe

    1998-01-01

    CdZnTe wide band gap compound semiconducting material offers promise as a room temperature operated gamma ray spectrometer. Position-dependent free charge carrier losses during transport can prevent efficient charge carrier extraction from semiconductor detectors and severely reduce energy resolution. Hole trapping losses in CdZnTe radiation detectors are far worse than electron trapping losses and resolution degradation in CdZnTe detectors results primarily

  4. Spectroscopic performance and long-term stability of thallium bromide radiation detectors

    Microsoft Academic Search

    Toshiyuki Onodera; Keitato Hitomi; Tadayoshi Shoji

    2006-01-01

    Thallium bromide (TlBr) is a very promising detector material used for X- and gamma-ray spectroscopy due to its high atomic number (Tl: 81 and Br: 35), high density (7.56g\\/cm3) and wide band gap (2.68eV). This paper reports results of research on spectroscopic performance and long-term stability of TlBr radiation detectors. TlBr detectors with simple planar structure have been fabricated from

  5. Study of the charge collection efficiency of CdZnTe radiation detectors

    Microsoft Academic Search

    Y. Nemirovsky; A. Ruzin; G. Asa; J. Gorelik

    1996-01-01

    The charge collection efficiency of CdZnTe radiation detectors with two different configurations: aSchottky diode detector and aresistive detector are compared. The average charge collection efficiencies for three different directions of irradiation (negative electrode,\\u000a positive electrode and perpendicular to the electric field) are calculated. The mobility-lifetime product of the CdZnTe substrates\\u000a is evaluated from the dependence of the measured spectra upon

  6. Effects of Te Inclusions on the Performance of CdZnTe Radiation Detectors

    Microsoft Academic Search

    A. E. Bolotnikov; N. M. Abdul-Jabbar; O. S. Babalola; G. S. Camarda; Y. Cui; A. M. Hossain; E. M. Jackson; H. C. Jackson; J. A. James; K. T. Kohman; A. L. Luryi; R. B. James

    2008-01-01

    Te inclusions existing at high concentrations in CdZnTe (CZT) material can degrade the performance of CZT detectors. These microscopic defects trap the free electrons generated by incident radiation, so entailing significant fluctuations in the total collected charge and thereby strongly affecting the energy resolution of thick (long-drift) detectors. Such effects were demonstrated in thin planar detectors, and, in many cases,

  7. Polarization Study of Defect Structure of CdTe Radiation Detectors

    Microsoft Academic Search

    R. Grill; E. Belas; J. Franc; M. Bugar; Š. Uxa; P. Moravec; P. Hoschl

    2011-01-01

    Polarization of CdTe radiation detectors in the dark was studied theoretically by taking into account a wide set of detector characteristics relevant to the polarization. Drift-diffusion and Poisson's equations were solved numerically in one dimension in time-resolved regime, where the characteristic time is determined by the charging of detector bulk. Shockley-Read-Hall model describes the trapping\\/detrapping of free carriers. Both diode-like

  8. Terahertz spectroscopy with a holographic Fourier transform spectrometer plus array detector using coherent synchrotron radiation

    SciTech Connect

    Nikolay I. Agladz, John Klopf, Gwyn Williams, Albert J. Sievers

    2010-06-01

    By use of coherent terahertz synchrotron radiation, we experimentally tested a holographic Fourier transform spectrometer coupled to an array detector to determine its viability as a spectral device. Somewhat surprisingly, the overall performance strongly depends on the absorptivity of the birefringent lithium tantalate pixels in the array detector.

  9. Growth and characterization of CdTe single crystals for radiation detectors

    Microsoft Academic Search

    Minoru Funaki; Tsutomu Ozaki; Kazuyuki Satoh; Ryoichi Ohno

    1999-01-01

    To improve the productivity of CdTe radiation detectors, the crystal growth by traveling heater method (THM) as well as the quality of the fabricated detectors were investigated. In the THM growth, optimization of the solvent volume was found to be essential because it affects the shape of the growth interface. The use of the slightly tilted seed from ?111?B was

  10. Radiation-detector optical-imaging device is of simplified construction

    NASA Technical Reports Server (NTRS)

    1965-01-01

    A simplified radiation detector was designed which employs an activated continuous front surface consisting of either the diffused or barrier type of semiconducting material with a grid structure on the nonactivated side of the detector. Its form may be either a rectangular coordinate or a polar coordinate system.

  11. Optimizing the SNR from a radiation detector with delay-line position-sensing electrodes

    Microsoft Academic Search

    Manhee Jeong; Mark D. Hammig; Subhashree Ramadoss

    2011-01-01

    In order to image the radiation field, instruments measure the position of interaction of the incident quanta, a task typically accomplished by partitioning the detector or its readout. We previously performed a fundamental investigation of the electrode design and pulse shape analysis routines required to optimize the detector's position resolution, when limited by both temporal and carrier uncertainties. If the

  12. Evaluating the performance of semiconductor radiation detectors through static charge analysis

    Microsoft Academic Search

    C. L. Lingren; J. F. Butler

    1998-01-01

    This paper presents a new approach to analyzing semiconductor radiation detectors based on considering: (1) static charge when all free charge has been collected and (2) capacitances between electrodes and trapped charge within the crystal. It avoids any direct consideration of free charge motion in the detector. The validity of this “static charge” approach is established by using it to

  13. Nuclear microprobe studies of the electronic transport properties of cadmium zinc telluride (CZT) radiation detectors

    Microsoft Academic Search

    Gyorgy Vizkelethy; Barney L. Doyle; David S. Walsh; Ralph B. James

    2000-01-01

    Ion Beam Induced Charge Collection (IBICC) is a proven albeit relatively new method to measure the electronic transport properties of room temperature radiation detectors. Using an ion microbeam, the charge collection efficiency of CZT detectors can be mapped with submicron resolution and maps of the electron mobility and lifetime can be calculated. The nuclear microprobe can be used not only

  14. Simulation of ion beam induced current in radiation detectors and microelectronic devices

    Microsoft Academic Search

    Gyorgy Vizkelethy

    2011-01-01

    Ion Beam Induced Charge (IBIC) is the basic mechanism of the operation of semiconductor detectors and it can lead to Single Event Effects (SEEs) in microelectronic devices. To be able to predict SEEs in ICs and detector responses one needs to be able to simulate the radiation-induced current as the function of time on the electrodes of the devices and

  15. RADIATION-HARD ASICS FOR OPTICAL DATA TRANSMISSION IN THE ATLAS PIXEL DETECTOR

    E-print Network

    Gan, K. K.

    RADIATION-HARD ASICS FOR OPTICAL DATA TRANSMISSION IN THE ATLAS PIXEL DETECTOR K.K. GAN, K.E. ARMS-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip diode. We have successfully implemented both ASICs in 0.25 mm CMOS technology using enclosed layout

  16. LiF:Mg,Ti (MTT) TL Detectors optimised for high-LET radiation dosimetry

    Microsoft Academic Search

    P. Bilski; M. Budzanowski; P. Olko; E. Mandowska

    2004-01-01

    The properties of LiF:Mg,Ti (distributed as, e.g., TLD-100 or MTS-N), the most frequently used thermoluminescent detector, have been optimised for measurements of sparsely ionising radiation (gamma rays), typically encountered in radiation protection or clinical dosimetry. However, these detectors need also to be applied in conditions of mixed-field dosimetry with a high-LET component, such as those encountered in heavy ion beams

  17. An investigation of the use of semiconductors as detectors of nuclear radiation 

    E-print Network

    Ivy, Edward Weber

    1960-01-01

    AN INVESTIGATION OF THE USE OF SEMICONDUCTORS AS DETECTORS OF NUCLEAR RADIATION A Thesis By EDWARD WEBER IVY Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August l960 Major Subject: Electrical Engineering AN INVESTIGATION OF THE USE OF SEMICONDUCTORS AS DETECTORS OF NUCLEAR RADIATION A Thesis By EDWARD WEBER IVY Approved as to style and content by: (Chai man of Co ittee...

  18. Pulse-shape discrimination techniques for correcting the effects of radiation damage in germanium coaxial detectors

    NASA Astrophysics Data System (ADS)

    Ho, W. C. G.; Boggs, S. E.; Lin, R. P.; Slassi-Sennou, S.; Madden, N. W.; Pehl, R. H.; Hull, E. L.

    Pusle-shape discrimination (PSD) techniques on current pulses from coaxial germanium detectors can significantly correct for charge losses due to hole trapping caused by radiation damage. Numerical simulations of PSD indicate that by measuring the two largest photon interaction locations and correcting the energy depositions separately, a significant recovery of the energy resolution and the Gaussian line shape of narrow lines in radiation damaged detectors can be obtained.

  19. Radiation hardness of SiC based ions detectors for influence of the relative protons

    Microsoft Academic Search

    A. M Ivanov; N. B Strokan; D. V Davydov; N. S Savkina; A. A Lebedev; Yu. T Mironov; G. A Riabov; E. M Ivanov

    2001-01-01

    Nuclear detector radiation hardness is very important for key experiments in high-energy physics, where the irradiation fluence of relativistic particles can be as high as 1015cm?2. In this work, we investigate the radiation hardness of SiC Schottky diode detectors ?600?m, obtained by magnetron sputtering of Ni on surface of 6H–SiC films, grown by sublimation epitaxy in vacuum. Irradiation has been

  20. An investigation of the use of semiconductors as detectors of nuclear radiation

    E-print Network

    Ivy, Edward Weber

    1960-01-01

    AN INVESTIGATION OF THE USE OF SEMICONDUCTORS AS DETECTORS OF NUCLEAR RADIATION A Thesis By EDWARD WEBER IVY Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August l960 Major Subject: Electrical Engineering AN INVESTIGATION OF THE USE OF SEMICONDUCTORS AS DETECTORS OF NUCLEAR RADIATION A Thesis By EDWARD WEBER IVY Approved as to style and content by: (Chai man of Co ittee...

  1. Monte Carlo modelling of a silicon strip detector for microbeam radiation therapy

    Microsoft Academic Search

    Ashley Cullen; Michael Lerch; Marco Petasecca; Anatoly Rosenfeld

    Microbeam radiation therapy is an experimental technique utilising synchrotron X-rays collimated into a planar array of microbeams. Due to the complex structure of the radiation field and high dose rate, this introduces dosimetric challenges. Current dosimetric methods are inadequate in that they lack either real-time readout, or high spatial resolution. A detector system, consisting of the Silicon Multi-Strip Detector and

  2. Development of bulk GaAs room temperature radiation detectors

    Microsoft Academic Search

    D. S. McGregor; G. F. Knoll; Y. Eisen; R. Brake

    1992-01-01

    Various configurations of Schottky diode detectors were fabricated with bulk crystals of liquid encapsulated Czochralski (LEC) semi-insulating undoped GaAs material. Basic detector construction utilized one Ti\\/Au Schottky contact and one Au\\/Ge\\/Ni alloyed ohmic contact. Pulsed X-ray analysis indicated pulse decay times dependent on bias voltage. Pulse height analysis disclosed nonuniform electric field distributions across the detectors tentatively explained as a

  3. Fast infrared detectors for beam diagnostics with synchrotron radiation

    Microsoft Academic Search

    A. Bocci; A. Marcelli; E. Pace; A. Drago; M. Piccinini; M. Cestelli Guidi; A. De Sio; D. Sali; P. Morini; J. Piotrowski

    2007-01-01

    Beam diagnostic is a fundamental constituent of any particle accelerators either dedicated to high-energy physics or to synchrotron radiation experiments. All storage rings emit radiations. Actually they are high brilliant sources of radiation: the synchrotron radiation emission covers from the infrared range to the X-ray domain with a pulsed structure depending on the temporal characteristics of the stored beam. The

  4. Radiation Effects on LWS Detectors and Deglitching of LWS Data

    Microsoft Academic Search

    M. Burgdorf; A. Harwood; S. D. Sidher

    2003-01-01

    Glitches are caused by the effects of ionising particles (either a primary cosmic ray, interplanetary or belt electron, or a secondary generated in the spacecraft structure) on the detectors. There was roughly one glitch per ten seconds per detector during the normal period of LWS operation. These energetic particles cause a sudden jump in the ramp voltage, due to a

  5. Method for mapping charge pulses in semiconductor radiation detectors

    Microsoft Academic Search

    T. H. Prettyman

    1999-01-01

    An efficient method for determining the distribution of charge pulses produced by semiconductor detectors is presented. The method is based on a quasi-steady-state model for semiconductor detector operation. A complete description of the model and the underlying assumptions are given. Mapping of charge pulses is accomplished by solving an adjoint carrier continuity equation. The solution of the adjoint equation yields

  6. Theoretical framework for mapping pulse shapes in semiconductor radiation detectors

    Microsoft Academic Search

    T. H. Prettyman

    1999-01-01

    An efficient method for calculating of charge pulses produced by semiconductor detectors is presented. The method is based on a quasi-steady-state model for semiconductor detector operation. A complete description of the model and underlying assumptions is given. Mapping of charge pulses is accomplished by solving an adjoint carrier continuity equation. The solution of the adjoint equation yields Green's function, a

  7. On the charge multiplication mechanism in silicon radiation detectors

    Microsoft Academic Search

    V. F. Kushniruk; I. V. Kuznetsov; Yu. G. Sobolev

    1997-01-01

    The analysis of experimental data obtained for different silicon detectors irradiated by heavy charged particles with wide mass and energy range was carried out. It is shown that the experimental results are in good agreement with a model based on charge accumulation close to the entrance detector electrode in the course of the charge collection process. The accumulation of a

  8. Radiation detector signal processing using sampling kernels without bandlimiting constraints

    Microsoft Academic Search

    Jürgen Stein; Marcus J. Neuer; Claus-Michael Herbach; Guntram Pausch; Kai Ruhnau

    2007-01-01

    For the development of digital signal processing systems for fast scintillation detectors we comprehensively study the modeling of nuclear signals, deconvolution of detector pulses and signal sampling. Applications for new scintillators with light decay times of a few nanoseconds demand suitable low power digital systems running at lowest possible sampling rates. We are interested in accurate sub-nanosecond timing and optimal

  9. Radiation detectors based on microchannel plates for free-electron lasers

    NASA Astrophysics Data System (ADS)

    Syresin, E.; Brovko, O.; Grebentsov, A.; Zamjatin, N.; Shabunov, A.; Yurkov, M.; Gruenert, J.; Freund, W.; Novikov, D.; Basta, R.; Fiala, T.; Hedbavny, P.

    2014-11-01

    Detectors based on microchannel plates are used to detect the radiation of free-electron lasers operating in short-wavelength ranges. We present descriptions of radiation detectors for the FLASH free-electron laser (DESY, Hamburg) that operates in vacuum ultraviolet and soft X-ray wavelength ranges (4-100 nm) and detectors for the European X-ray free electron laser that is being constructed in Hamburg and is designed to operate in the X-ray wavelength range from 0.05 to 4.3 nm.

  10. DEVELOPMENT OF CdZnTe RADIATION DETECTORS

    SciTech Connect

    BOLOTNIKOV, A.; CAMARDA, G.; HOSSAIN, A.; KIM, K.H.; YANG, G.; GUL, R.; CUI, Y.; AND JAMES, R.B.

    2011-10-23

    Cadmium Zinc Telluride (CdZnTe or CZT) is a very attractive material for room-temperature semiconductor detectors because of its wide band-gap and high atomic number. Despite these advantages, CZT still presents some material limitations and poor hole mobility. In the past decade most of the developing CZT detectors focused on designing different electrode configurations, mainly to minimize the deleterious effect due to the poor hole mobility. A few different electrode geometries were designed and fabricated, such as pixelated anodes and Frisch-grid detectors developed at Brookhaven National Lab (BNL). However, crystal defects in CZT materials still limit the yield of detector-grade crystals, and, in general, dominate the detector's performance. In the past few years, our group's research extended to characterizing the CZT materials at the micro-scale, and to correlating crystal defects with the detector's performance. We built a set of unique tools for this purpose, including infrared (IR) transmission microscopy, X-ray micro-scale mapping using synchrotron light source, X-ray transmission- and reflection-topography, current deep level transient spectroscopy (I-DLTS), and photoluminescence measurements. Our most recent work on CZT detectors was directed towards detailing various crystal defects, studying the internal electrical field, and delineating the effects of thermal annealing on improving the material properties. In this paper, we report our most recent results.

  11. Radiation hardness of a wide-bandgap material by the example of SiC nuclear radiation detectors

    NASA Astrophysics Data System (ADS)

    Ivanov, A. M.; Strokan, N. B.; Lebedev, A. A.

    2012-05-01

    A polarization effect characteristically occurs in detectors based on wide-bandgap materials at considerable concentrations of radiation defects. The appearance of an electromotive force in the bulk of a detector is due to the long-term capture of carriers at deep levels related to radiation centers. The kinetics and strength of the polarization field have been determined. The carrier capture by the radiation centers can be controlled by varying the detector temperature, with a compromise reached at the "optimal" temperature between the generation current and the position of the deepest of the levels whose contribution to the loss of charge via capture is negligible. It has been found that the depth of a level of this kind (related to the energy gap width) is close to 1/3, irrespective of a material. The optimal temperatures are strictly individual for materials.

  12. Monte Carlo simulation of the performance of the D0 transition radiation detector

    Microsoft Academic Search

    Y. Ducros; F. Feinstein; J. R. Hubbard; Ph. Mangeot; B. Mansoulié; J. Teiger; A. Zylberstejn

    1989-01-01

    We present a comparison of a Monte Carlo simulation of the D0 Transition Radiation Detector with the data obtained with a prototype. The X-ray production is calculated taking into account the irregular distribution of the gaps between the foils of the radiator. The delta rays are simulated by using the cluster energy deposition spectrum given by the photoabsorption ionisation model.

  13. Development of a synthetic diamond radiation detector with a boron doped CVD diamond contact

    Microsoft Academic Search

    Junichi Kaneko; Masaki Katagiri; Yujiro Ikeda; Takeo Nishitani

    1999-01-01

    A boron doped CVD diamond contact was applied to a diamond radiation detector for suppressing a polarization phenomenon. A boron doped CVD diamond layer was grown on a synthetic type IIa single crystal diamond; it was then used as a contact. The contact was completely free from radiation damage which is unavoidable in a contact made by an ordinary ion

  14. Design of terahertz detector based on radiation-induced magnetoresistance oscillations

    NASA Astrophysics Data System (ADS)

    Zhou, Q. S.; Cao, J. C.; Qi, M.

    2010-06-01

    We have investigated the longitudinal resistivity of two-dimensional (2D) electron gas driven by microwave and magnetic field by using the balance-equation theory. Radiation-induced magnetoresistance oscillations have been reproduced. The period-in-the-inverse-magnetic-field is determined by radiation frequency. This property can be used to design a terahertz detector. The detection is realized by applying a time-varying magnetic field on a 2D electron device and then measuring the difference of longitudinal resistivity with and without radiation. This kind of detector has high sensitivity and high immunity.

  15. Extended Defects in CdZnTe Radiation Detectors

    Microsoft Academic Search

    Aleksey E. Bolotnikov; Stephen O. Babalola; Giuseppe S. Camarda; Henry Chen; S. Awadalla; Yonggang Cui; Stephrn U. Egarievwe; Petro M. Fochuk; Rastgo Hawrami; Anwar Hossain; Jesse R. James; I. J. Nakonechnyj; J. MacKenzie; Ge Yang; Chao Xu; Ralph B. James

    2009-01-01

    Large-volume CdZnTe (CZT) single crystals with electron lifetime exceeding 10 mus have recently become commercially available. This opened the opportunity for making room temperature CZT gamma-ray detectors with extended thicknesses and larger effective areas. However, the extended defects that are present even in the highest-quality material remain a major drawback which affects the availability and cost of large CZT detectors.

  16. Study of the characteristics of silicon MESA radiation detectors

    Microsoft Academic Search

    D. Chren; M. Juneau; Z. Kohout; C. Lebel; V. Linhart; P. Roy; A. Saintonge; B. Sopko

    2001-01-01

    The MESA process for building silicon diodes is described. I–V and C–V features of MESA detectors are given. Results of pulse-height spectra measurements with ? particles incident on the front and back sides of a MESA diode establish the energy resolution of these detectors, show the evolution of their response as a function of applied bias voltage, and bring information

  17. Calibration of VUV spectrometer-detector system using synchrotron radiation

    Microsoft Academic Search

    Armon McPherson; Ned Rouze; W. B. Westerveld; John S. Risley

    1986-01-01

    A new technique and apparatus have been developed for the measurement of absolute electron impact photoemission cross sections in the 30--150-nm wavelength range. Synchrotron light is used as the primary intensity standard for the calibration of the detection efficiency of a vacuum ultraviolet (VUV) spectrometer-detector system. A multiadjustable manipulator was used to position precisely a Seya-Namioka-type spectrometer-detector system with respect

  18. Simulation of ion beam induced current in radiation detectors and microelectronic devices.

    SciTech Connect

    Vizkelethy, Gyorgy

    2009-10-01

    Ionizing radiation is known to cause Single Event Effects (SEE) in a variety of electronic devices. The mechanism that leads to these SEEs is current induced by the radiation in these devices. While this phenomenon is detrimental in ICs, this is the basic mechanism behind the operation of semiconductor radiation detectors. To be able to predict SEEs in ICs and detector responses we need to be able to simulate the radiation induced current as the function of time. There are analytical models, which work for very simple detector configurations, but fail for anything more complex. On the other end, TCAD programs can simulate this process in microelectronic devices, but these TCAD codes costs hundreds of thousands of dollars and they require huge computing resources. In addition, in certain cases they fail to predict the correct behavior. A simulation model based on the Gunn theorem was developed and used with the COMSOL Multiphysics framework.

  19. Detector recovery\\/improvement via elevated-temperature-annealing (DRIVE): a new approach for Si detector applications in high radiation environment in SLHC

    Microsoft Academic Search

    Zheng Li; E. Verbitskaya; V. Eremin; A. Ivanov; J. Harkonen; E. Tuovinen; P. Luukka

    2005-01-01

    A new approach to improve Si detector radiation hardness\\/tolerance, termed as DRIVE (detector recovery\\/improvement via elevated-temperature-annealing), has been realized by annealing of oxygen-rich (magnetic CZ, MCZ), proton-irradiated Si detectors (with negative space charge before annealing) at medium temperature for a few hours. The DRIVE approach has been proved to lead to the dramatic decrease in detector leakage current, decrease in

  20. A program in detector development for the US synchrotron radiation community

    SciTech Connect

    Thompson, A.; Mills, D.; Naday, S.; Gruner, S.; Siddons, P.; Arthur, J.; Wehlitz, R.; Padmore, H.

    2001-07-14

    There is a clear gulf between the capabilities of modern synchrotrons to deliver high photon fluxes, and the capabilities of detectors to measure the resulting photon, electron or ion signals. While a huge investment has been made in storage ring technology, there has not to date been a commensurate investment in detector systems. With appropriate detector technology, gains in data rates could be 3 to 4 orders of magnitude in some cases. The US community working in detector technology is under-funded and fragmented and works without the long term funding commitment required for development of the most advanced detector systems. It is becoming apparent that the US is falling behind its international competitors in provision of state-of-the-art detector technology for cutting edge synchrotron radiation based experiments.

  1. Electromagnetic and nuclear radiation detector using micromechanical sensors

    DOEpatents

    Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN); Wachter, Eric A. (Oak Ridge, TN)

    2000-01-01

    Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic spectrum can be imaged with picoJoule sensitivity, and specific absorptive coatings can be used for selective sensitivity in specific wavelength bands. Microcantilevers coated with optical cross-linking polymers are useful as integrating optical radiation dosimeters. Nuclear radiation dosimetry is possible by fabricating cantilevers from materials that are sensitive to various nuclear particles or radiation. Upon exposure to radiation, the cantilever bends due to stress and its resonance frequency shifts due to changes in elastic properties, based on cantilever shape and properties of the coating.

  2. Radiation Hard AlGaN Detectors and Imager

    SciTech Connect

    None

    2012-05-01

    Radiation hardness of AlGaN photodiodes was tested using a 65 MeV proton beam with a total proton fluence of 3x10{sup 12} protons/cm{sup 2}. AlGaN Deep UV Photodiode have extremely high radiation hardness. These new devices have mission critical applications in high energy density physics (HEDP) and space explorations. These new devices satisfy radiation hardness requirements by NIF. NSTec is developing next generation AlGaN optoelectronics and imagers.

  3. Electromagnetic and nuclear radiation detector using micromechanical sensors

    Microsoft Academic Search

    Thomas G. Thundat; Robert J. Warmack; Eric A. Wachter

    2000-01-01

    Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and\\/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic

  4. Strip detector for high spatial resolution dosimetry in radiation therapy

    Microsoft Academic Search

    Ashley James Cullen

    2009-01-01

    Radiation therapy is an established modality in the treatment of tumours. With treatments ever evolving and increasing in terms of their complexities, the need arises to ensure the best quality treatment is delivered; the survival of the patient relies upon it. A modern treatment such as Intensity Modulated Radiation Therapy employs steep dose gradients varying dynamically to deliver complex dose

  5. Study of edgeless radiation detector with 3D spatial mapping technique

    NASA Astrophysics Data System (ADS)

    Wu, X.; Kalliopuska, J.; Jak?bek, M.; Jak?bek, J.; Gädda, A.; Eränen, S.

    2014-04-01

    Edgeless radiation detector has gained increased attention due to its superiority in the defect-free edge fabrication and the capability to minimize the insensitive area at the detector edge. The doped edge in the edgeless detector is at the same potential with the back plane and causes a local distortion of the electric field at the detector edge. The deformed electric field alters the charge collection of the edge pixel and leads to an inaccurate charge interpolation. To study the influence of active edges on the response of edge pixels, we used an advanced X-ray based 3D spatial mapping technique to visually show the charge collection volumes of pixels. Various edgeless detectors with diverse polarities, thicknesses and edge-to-pixel distances were investigated. For the n-on-p (n+/p-/p+) edgeless detector, the mapping shows that the p-spray isolation method has the advantage of achieving a greater sensitive edge region compared to the p-stop method. And the p-on-p (p+/p-/n+) edgeless detector, reported for the first time, functions for both spatial and energy signals. The n-type edgeless detectors were studied together with a standard Medipix detector with the guard ring design. The results show that the edgeless detector is capable of maximally utilizing the edge region of the detector as the charge sensitive volume, while the standard Medipix detector has still vast insensitive region at the edge. The X-ray spectroscopic measurements with 241Am and 55Fe sources performed on all detectors gives a similar conclusion and proves the 3D spatial mapping results.

  6. Characterization of a novel two dimensional diode array the ''magic plate'' as a radiation detector for radiation therapy treatment

    SciTech Connect

    Wong, J. H. D.; Fuduli, I.; Carolan, M.; Petasecca, M.; Lerch, M. L. F.; Perevertaylo, V. L.; Metcalfe, P.; Rosenfeld, A. B. [Centre for Medical Radiation Physics, University of Wollongong, NSW 2522, Australia and Faculty of Medicine, University of Malaya, Kuala Lumpur 50603 (Malaysia); Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 (Australia); Illawarra Cancer Care Centre, Wollongong Hospital, NSW 2500, Australia and Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 (Australia); Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 (Australia); SPA BIT, Kiev, Ukraine, 04136 (Ukraine); Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 (Australia)

    2012-05-15

    Purpose: Intensity modulated radiation therapy (IMRT) utilizes the technology of multileaf collimators to deliver highly modulated and complex radiation treatment. Dosimetric verification of the IMRT treatment requires the verification of the delivered dose distribution. Two dimensional ion chamber or diode arrays are gaining popularity as a dosimeter of choice due to their real time feedback compared to film dosimetry. This paper describes the characterization of a novel 2D diode array, which has been named the ''magic plate'' (MP). It was designed to function as a 2D transmission detector as well as a planar detector for dose distribution measurements in a solid water phantom for the dosimetric verification of IMRT treatment delivery. Methods: The prototype MP is an 11 x 11 detector array based on thin (50 {mu}m) epitaxial diode technology mounted on a 0.6 mm thick Kapton substrate using a proprietary ''drop-in'' technology developed by the Centre for Medical Radiation Physics, University of Wollongong. A full characterization of the detector was performed, including radiation damage study, dose per pulse effect, percent depth dose comparison with CC13 ion chamber and build up characteristics with a parallel plane ion chamber measurements, dose linearity, energy response and angular response. Results: Postirradiated magic plate diodes showed a reproducibility of 2.1%. The MP dose per pulse response decreased at higher dose rates while at lower dose rates the MP appears to be dose rate independent. The depth dose measurement of the MP agrees with ion chamber depth dose measurements to within 0.7% while dose linearity was excellent. MP showed angular response dependency due to the anisotropy of the silicon diode with the maximum variation in angular response of 10.8% at gantry angle 180 deg. Angular dependence was within 3.5% for the gantry angles {+-} 75 deg. The field size dependence of the MP at isocenter agrees with ion chamber measurement to within 1.1%. In the beam perturbation study, the surface dose increased by 12.1% for a 30 x 30 cm{sup 2} field size at the source to detector distance (SDD) of 80 cm whilst the transmission for the MP was 99%. Conclusions: The radiation response of the magic plate was successfully characterized. The array of epitaxial silicon based detectors with ''drop-in'' packaging showed properties suitable to be used as a simplified multipurpose and nonperturbing 2D radiation detector for radiation therapy dosimetric verification.

  7. Preparation and Characteristics of Natural Diamond Nuclear Radiation Detectors

    Microsoft Academic Search

    S. F. Kozlov; R. Stuck; M. Hage-Ali; P. Siffert

    1975-01-01

    It is shown that natural diamond can be used as a homogeneous conduction counter with near complete charge collection, even over a long period of time. Indeed, polarization effects have been suppressed by making the back contact of the detector injecting under the influence of the applied field in order to compensate for trapped charge carriers. The electric and detection

  8. Radiation-hard semiconductor detectors for SuperLHC

    Microsoft Academic Search

    M. Bruzzi; J. Adey; A. Al-Ajili; P. Alexandrov; G. Alfieri; P. P. Allport; A. Andreazza; M. Artuso; S. Assouak; B. S. Avset; L. Barabash; E. Baranova; A. Barcz; A. Basile; R. Bates; N. Belova; S. F. Biagi; G. M. Bilei; D. Bisello; A. Blue; A. Blumenau; V. Boisvert; G. Bolla; G. Bondarenko; E. Borchi; L. Borrello; D. Bortoletto; M. Boscardin; L. Bosisio; T. J. V. Bowcock; T. J. Brodbeck; J. Broz; A. Brukhanov; A. Brzozowski; M. Buda; P. Buhmann; C. Buttar; F. Campabadal; D. Campbell; A. Candelori; G. Casse; A. Cavallini; A. Chilingarov; D. Chren; V. Cindro; M. Citterio; P. Collins; R. Coluccia; D. Contarato; J. Coutinho; D. Creanza; W. Cunningham; V. Cvetkov; G.-F. Dalla Betta; G. Davies; I. Dawson; W. de Boer; M. De Palma; R. Demina; P. Dervan; A. Dierlamm; S. Dittongo; L. Dobrzanski; Z. Dolezal; A. Dolgolenko; T. Eberlein; V. Eremin; C. Fall; F. Fasolo; T. Ferbel; F. Fizzotti; C. Fleta; E. Focardi; E. Forton; S. Franchenko; E. Fretwurst; F. Gamaz; C. Garcia; J. E. Garcia-Navarro; E. Gaubas; M.-H. Genest; K. A. Gill; K. Giolo; M. Glaser; C. Goessling; V. Golovine; S. González Sevilla; I. Gorelov; J. Goss; A. Gouldwell; G. Grégoire; P. Gregori; E. Grigoriev; C. Grigson; A. Grillo; A. Groza; J. Guskov; L. Haddad; J. Härkönen; R. Harding; F. Hauler; S. Hayama; M. Hoeferkamp; F. Hönniger; T. Horazdovsky; R. Horisberger; M. Horn; A. Houdayer; B. Hourahine; A. Hruban; G. Hughes; I. Ilyashenko; K. Irmscher; A. Ivanov; K. Jarasiunas; T. Jin; B. K. Jones; R. Jones; C. Joram; L. Jungermann; E. Kalinina; P. Kaminski; A. Karpenko; A. Karpov; V. Kazlauskiene; V. Kazukauskas; V. Khivrich; V. Khomenkov; J. Kierstead; J. Klaiber-Lodewigs; M. Kleverman; R. Klingenberg; P. Kodys; Z. Kohout; S. Korjenevski; A. Kowalik; R. Kozlowski; M. Kozodaev; G. Kramberger; O. Krasel; A. Kuznetsov; S. Kwan; S. Lagomarsino; T. Lari; K. Lassila-Perini; V. Lastovetsky; G. Latino; S. Latushkin; S. Lazanu; I. Lazanu; C. Lebel; K. Leinonen; C. Leroy; Z. Li; G. Lindström; L. Lindstrom; V. Linhart; A. Litovchenko; P. Litovchenko; V. Litvinov; A. Lo Giudice; M. Lozano; Z. Luczynski; P. Luukka; A. Macchiolo; A. Mainwood; L. F. Makarenko; I. Mandi?; C. Manfredotti; S. Marti i Garcia; S. Marunko; K. Mathieson; A. Mozzanti; J. Melone; D. Menichelli; C. Meroni; A. Messineo; S. Miglio; M. Mikuz; J. Miyamoto; M. Moll; E. Monakhov; F. Moscatelli; L. Murin; F. Nava; D. Naoumov; E. Nossarzewska-Orlowska; S. Nummela; J. Nysten; P. Olivero; V. Oshea; T. Palviainen; C. Paolini; C. Parkes; D. Passeri; U. Pein; G. Pellegrini; L. Perera; M. Petasecca; B. Piatkowski; C. Piemonte; G. U. Pignatel; N. Pinho; I. Pintilie; L. Pintilie; L. Polivtsev; P. Polozov; A. I. Popa; J. Popule; S. Pospisil; G. Pucker; V. Radicci; J. M. Rafí; F. Ragusa; M. Rahman; R. Rando; R. Roeder; T. Rohe; S. Ronchin; C. Rott; P. Roy; A. Roy; A. Ruzin; A. Ryazanov; H. F. W. Sadrozinski; S. Sakalauskas; M. Scaringella; L. Schiavulli; S. Schnetzer; B. Schumm; S. Sciortino; A. Scorzoni; G. Segneri; S. Seidel; A. Seiden; G. Sellberg; P. Sellin; D. Sentenac; I. Shipsey; P. Sicho; T. Sloan; M. Solar; S. Son; B. Sopko; N. Spencer; J. Stahl; I. Stavitski; D. Stolze; R. Stone; J. Storasta; N. Strokan; W. Strupinski; M. Sudzius; B. Surma; J. Suuronen; A. Suvorov; B. G. Svensson; P. Tipton; M. Tomasek; C. Troncon; A. Tsvetkov; E. Tuominen; E. Tuovinen; T. Tuuva; M. Tylchin; H. Uebersee; J. Uher; M. Ullán; J. V. Vaitkus; P. Vanni; J. Velthuis; G. Verzellesi; E. Verbitskaya; V. Vrba; G. Wagner; I. Wilhelm; S. Worm; V. Wright; R. Wunstorf; P. Zabierowski; A. Zaluzhny; M. Zavrtanik; M. Zen; V. Zhukov; N. Zorzi

    2005-01-01

    An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 1035cm?2s?1 has been envisaged to extend the physics reach of the machine. An efficient tracking down to a few centimetres from the interaction point will be required to exploit the physics potential of the upgraded LHC. As a consequence, the semiconductor detectors close to the

  9. Transition Radiation Detector to Search for Dark Matter in Space

    E-print Network

    Roma "La Sapienza", Università di

    the modules The tubes are arranged into 328 modules of 16 straws each AMS-02AMS-02 AMS-02 on ISSAMS-02 on ISS Station (ISS) for a 3 years mission at a mean altitude of 400 km The detector will perform primary cosmic ray spectroscopy allowing the direct search for antimatter and the indirect

  10. Radiation Tests for a Single-GEM Loaded Gaseous Detector

    E-print Network

    Lee, Kyong Sei; Kim, Sang Yeol; Park, Sung Keun

    2014-01-01

    We report on the systematic study of a single-gas-electron-multiplication (GEM) loaded gaseous detector developed for precision measurements of high-energy particle beams and dose-verification measurements. In the present study, a 256-channel prototype detector with an active area of 16$\\times$16 cm$^{2}$, operated in a continuous current-integration-mode signal-processing method, was manufactured and tested with x rays emitted from a 70-kV x-ray generator and 43-MeV protons provided by the MC50 proton cyclotron at the Korea Institute of Radiological and Medical Science (KIRAMS). The amplified detector response was measured for the x rays with an intensity of about 5$\\times$10$^{6}$ Hz cm$^{-2}$. The linearity of the detector response to the particle flux was examined and validated by using 43-MeV proton beams. The non-uniform development of the amplification for the gas electrons in space was corrected by applying proper calibration to the channel responses of the measured beam-profile data. We concluded fro...

  11. Thickness scalability of large volume Cadmium Zinc Telluride high resolution radiation detectors

    Microsoft Academic Search

    S. A. Awadallat; H. Chent; J. Mackenzie; P. Lu; K. Iniewski; P. Marthandam; R. Redden; G. Bindley; Z. He; F. Zhang; M. Groza; A. Burger; D. R. Mayo; C. L. Sullivan

    2008-01-01

    In an effort to optimize the spectroscopic performance of large volume Cadmium Zinc Telluride (CZT) radiation detectors grown by the Traveling Heater Method (THM), especially for higher energy gamma detection applications, bulk material and pixellated detector performance of THM CZT crystals at 15mm-thick and 10mm-thick were compared to that at 5mm-thick. We demonstrate that the outstanding performance of monolithic pixellated

  12. Thermal detector units for monitoring thin-film radiation-induced polymerization

    Microsoft Academic Search

    J. D. Wisnosky; R. M. Fantazier

    1981-01-01

    Detector cell units have been designed and fabricated to monitor radiation-induced polymerizations in neat, thin-film (4-10 mils) resin systems. The cells utilize rapid-response, thin-foil differential thermocouples to measure the heat evolved during a photopolymerization reaction. Analysis of reaction exotherm curves from the photopolymerization of common resin systems showed that the thermal response of the detector cells was comparable to that

  13. Energetic particle radiations measured by particle detector on board CBERS-1 satellite

    Microsoft Academic Search

    YongQiang Hao; Zuo Xiao; Hong Zou; DongHe Zhang

    2007-01-01

    Using the data measured by energetic particle detector on board CBERS-01 and-02 for the past five years, statistics was made\\u000a to show the general features of MeV electrons and protons along a solar synchronous orbit at an altitude of 780 km. This height\\u000a is in the bottom region of the Earth’s radiation belts. Detectors are inside the satellite cabinet and

  14. I. Vibration Isolation for Gravitational Radiation Detectors. II. QSO Heavy-Element Absorption Systems

    Microsoft Academic Search

    Thomas Lytell Aldcroft

    1993-01-01

    In Part 1 of the thesis we discuss passive vibration isolation systems for ultralow temperature gravitational radiation detectors, using the detector at Stanford University as the primary example. The basic theory of such isolation systems is reviewed and we describe methods of analysis for one-degree-of-freedom isolators. Next we discuss general design considerations, optimization and detailed analysis of six degree-of-freedom isolators.

  15. Coaxial nuclear radiation detector with deep junction and radial field gradient

    Microsoft Academic Search

    Hall

    1979-01-01

    Germanium radiation detectors are manufactured by diffusion lithium into high purity p-type germanium. The diffusion is most readily accomplished from a lithium-lead-bismuth alloy at approximately 430° and is monitored by a quartz half cell containing a standard composition of this alloy. Detectors having n-type cores may be constructed by converting high purity p-type germanium to n-type by a lithium diffusion

  16. X-ray diffuse scattering for evaluation of wide bandgap semiconductor nuclear radiation detectors

    Microsoft Academic Search

    M. S Goorsky; H. Yoon; M. Schieber; R. B James; D. S McGregor; M. Natarajan

    1996-01-01

    The crystalline perfection of solid state radiation detectors was examined using triple axis x-ray diffraction. Triple axis techniques provide a means to analyze the origin of diffraction peak broadening: the effects of strain (due to deviations in alloy composition or stoichiometry) and lattice tilts (mosaic structure) can be separated. Cd1 ? xZnxTe (x ? 0.1), HgI2, and GaAs detector materials

  17. Structural properties of cadmium zinc telluride and their effects on nuclear radiation detector performance

    Microsoft Academic Search

    Hojun Yoon

    1998-01-01

    Structural properties of cadmium zinc telluride, Cdsb{1-x}Znsb{x}Te, used as room temperature nuclear radiation detectors are characterized in relation to various detector properties. Alloy (zinc) composition variation is determined by triple axis diffraction lattice parameter measurements and its effects on the material resistivity are examined. Structural defects including cracks, grain\\/twin boundaries, mosaic structure, small angle tilt boundaries, and dislocations are characterized

  18. Radiation hard silicon detectors—developments by the RD48 (ROSE) collaboration

    Microsoft Academic Search

    G. Lindström; M. Ahmed; S. Albergo; P. Allport; D. Anderson; L. Andricek; M. M. Angarano; V. Augelli; N. Bacchetta; P. Bartalini; R. Bates; U. Biggeri; G. M. Bilei; D. Bisello; D. Boemi; E. Borchi; T. Botila; T. J. Brodbeck; M. Bruzzi; T. Budzynski; P. Burger; F. Campabadal; G. Casse; E. Catacchini; A. Chilingarov; P. Ciampolini; V. Cindro; M. J. Costa; D. Creanza; P. Clauws; C Da Via; G. Davies; W De Boer; R Dell’Orso; M De Palma; B. Dezillie; V. Eremin; O. Evrard; G. Fallica; G. Fanourakis; H. Feick; E. Fretwurst; L. Fonseca; J. Fuster; K. Gabathuler; M. Glaser; P. Grabiec; E. Grigoriev; G. Hall; M. Hanlon; F. Hauler; S. Heising; A. Holmes-Siedle; R. Horisberger; G. Hughes; M. Huhtinen; I. Ilyashenko; A. Ivanov; B. K Jones; L. Jungermann; A. Kaminsky; Z. Kohout; G. Kramberger; M. Kuhnke; S. Kwan; F. Lemeilleur; C. Leroy; M. Letheren; Z. Li; T. Ligonzo; V. Linhart; P. Litovchenko; D. Loukas; M. Lozano; Z. Luczynski; G. Lutz; B. MacEvoy; S. Manolopoulos; A. Markou; C. Martinez; A. Messineo; M. Mikuz; M. Moll; E. Nossarzewska; G. Ottaviani; V. Oshea; G. Parrini; D. Passeri; D. Petre; A. Pickford; I. Pintilie; L. Pintilie; S. Pospisil; R. Potenza; C. Raine; J. M Rafi; P. N Ratoff; R. H Richter; P. Riedler; S. Roe; P. Roy; A. Ruzin; A. I. Ryazanov; A. Santocchia; L. Schiavulli; P. Sicho; I. Siotis; T. Sloan; W. Slysz; K. Smith; M. Solanky; B. Sopko; K. Stolze; B Sundby Avset; B. Svensson; C. Tivarus; G. Tonelli; A. Tricomi; S. Tzamarias; G. Valvo; A. Vasilescu; A. Vayaki; E. Verbitskaya; P. Verdini; V. Vrba; S. Watts; E. R Weber; M. Wegrzecki; I. Wegrzecka; P. Weilhammer; R. Wheadon; C. Wilburn; I. Wilhelm; R. Wunstorf; J. Wüstenfeld; J. Wyss; K. Zankel; P. Zabierowski; D Žontar

    2001-01-01

    The RD48 (ROSE) collaboration has succeeded to develop radiation hard silicon detectors, capable to withstand the harsh hadron fluences in the tracking areas of LHC experiments. In order to reach this objective, a defect engineering technique was employed resulting in the development of Oxygen enriched FZ silicon (DOFZ), ensuring the necessary O-enrichment of about 2×1017 O\\/cm3 in the normal detector

  19. Recent advancements in the development of radiation hard semiconductor detectors for S-LHC

    Microsoft Academic Search

    E. Fretwurst; J. Adey; A. Al-Ajili; G. Alfieri; P. P. Allport; M. Artuso; S. Assouak; B. S. Avset; L. Barabashi; A. Barcz; R. Bates; S. F. Biagi; G. M. Bilei; D. Bisello; A. Blue; A. Blumenau; V. Boisvert; G. Bolla; G. Bondarenko; E. Borchi; L. Borrello; D. Bortoletto; M. Boscardin; L. Bosisio; T. J. V. Bowcock; T. J. Brodbeck; J. Broz; M. Bruzzi; A. Brzozowski; M. Buda; P. Buhmann; C. Buttar; F. Campabadal; D. Campbell; A. Candelori; G. Casse; A. Cavallini; S. Charron; A. Chilingarov; D. Chren; V. Cindro; P. Collins; R. Coluccia; D. Contarato; J. Coutinho; D. Creanza; L. Cunningham; G.-F. Dalla Betta; I. Dawson; W. de Boer; M. De Palma; R. Demina; P. Dervan; S. Dittongo; Z. Dolezal; A. Dolgolenko; T. Eberlein; V. Eremin; C. Fall; F. Fasolo; T. Ferbel; F. Fizzotti; C. Fleta; E. Focardi; E. Forton; C. Garcia; J. E. Garcia-Navarro; E. Gaubas; M.-H. Genest; K. A. Gill; K. Giolo; M. Glaser; C. Goessling; V. Golovine; S. González Sevilla; I. Gorelov; J. Goss; A. Gouldwell Bates; G. Grégoire; P. Gregori; E. Grigoriev; A. A. Grillo; A. Groza; J. Guskov; L. Haddad; J. Härkönen; F. Hauler; M. Hoeferkamp; F. Hönniger; T. Horazdovsky; R. Horisberger; M. Horn; A. Houdayer; B. Hourahine; G. Hughes; I. Ilyashenko; K. Irmscher; A. Ivanov; K. Jarasiunas; K. M. H. Johansen; B. K. Jones; R. Jones; C. Joram; L. Jungermann; E. Kalinina; P. Kaminski; A. Karpenko; A. Karpov; V. Kazlauskiene; V. Kazukauskas; V. Khivrich; V. Khomenkov; J. Kierstead; J. Klaiber-Lodewigs; R. Klingenberg; P. Kodys; Z. Kohout; S. Korjenevski; M. Koski; R. Kozlowski; M. Kozodaev; G. Kramberger; O. Krasel; A. Kuznetsov; S. Kwan; S. Lagomarsino; K. Lassila-Perini; V. Lastovetsky; G. Latino; I. Lazanu; S. Lazanu; A. Lebedev; C. Lebel; K. Leinonen; C. Leroy; Z. Li; G. Lindström; V. Linhart; P. Litovchenko; A. Litovchenko; A. Lo Giudice; M. Lozano; Z. Luczynski; P. Luukka; A. Macchiolo; L. F. Makarenko; I. Mandi?; C. Manfredotti; N. Manna; S. Marti i Garcia; S. Marunko; K. Mathieson; J. Melone; D. Menichelli; A. Messineo; J. Metcalfe; S. Miglio; M. Mikuz; J. Miyamoto; M. Moll; E. Monakhov; F. Moscatelli; D. Naoumov; E. Nossarzewska-Orlowska; J. Nysten; P. Olivero; V. Oshea; T. Palviainen; C. Paolini; C. Parkes; D. Passeri; U. Pein; G. Pellegrini; L. Perera; M. Petasecca; C. Piemonte; G. U. Pignatel; N. Pinho; I. Pintilie; L. Pintilie; L. Polivtsev; P. Polozov; A. Popa; J. Popule; S. Pospisil; A. Pozza; V. Radicci; J. M. Rafí; R. Rando; R. Roeder; T. Rohe; S. Ronchin; C. Rott; A. Roy; A. Ruzin; H. F. W. Sadrozinski; S. Sakalauskas; M. Scaringella; L. Schiavulli; S. Schnetzer; B. Schumm; S. Sciortino; A. Scorzoni; G. Segneri; S. Seidel; A. Seiden; G. Sellberg; P. Sellin; D. Sentenac; I. Shipsey; P. Sicho; T. Sloan; M. Solar; S. Son; B. Sopko; V. Sopko; N. Spencer; J. Stahl; D. Stolze; R. Stone; J. Storasta; N. Strokan; M. Sudzius; B. Surma; A. Suvorov; B. G. Svensson; P. Tipton; M. Tomasek; A. Tsvetkov; E. Tuominen; E. Tuovinen; T. Tuuva; M. Tylchin; H. Uebersee; J. Uher; M. Ullán; J. V. Vaitkus; J. Velthuis; E. Verbitskaya; V. Vrba; G. Wagner; I. Wilhelm; S. Worm; V. Wright; R. Wunstorf; Y. Yiuri; P. Zabierowski; A. Zaluzhny; M. Zavrtanik; M. Zen; V. Zhukov; N. Zorzi

    2005-01-01

    The proposed luminosity upgrade of the Large Hadron Collider (S-LHC) at CERN will demand the innermost layers of the vertex detectors to sustain fluences of about 1016 hadrons\\/cm2. Due to the high multiplicity of tracks, the required spatial resolution and the extremely harsh radiation field new detector concepts and semiconductor materials have to be explored for a possible solution of

  20. HTLT oxygenated silicon detectors: radiation hardness and long-term stability

    Microsoft Academic Search

    Z. Li; B. Dezillie; M. Bruzzi; W. Chen; V. Eremin; E. Verbitskaya; P. Weilhammer

    2001-01-01

    Silicon detectors fabricated by BNLs high-temperature, long time (HTLT) oxidation technology have been characterized using various techniques for material\\/detector properties and radiation hardness with respect to gamma, proton and neutron irradiation. It has been found that a uniform oxygen distribution with a concentration of 4×1017\\/cm3 has been achieved in high-resistivity FZ silicon with our HTLT technology. With the standard HTLT

  1. Purification and preparation of TlBr crystal for room temperature radiation detector applications

    Microsoft Academic Search

    Icimone B. Oliveira; Fabio E. Costa; José F. D. Chubaci; Margarida M. Hamada

    2003-01-01

    Thallium bromide (TlBr) is a compound semiconductor with a high atomic number and wide band gap, being a very promising material to be used as room temperature radiation detectors. In this work, the commercial TlBr powder was used for growing crystals for detector applications. To reduce impurities, this material was purified by the zone refining technique. Trace impurities at ppb\\/ppm

  2. Novel p-JFET embedded in silicon radiation detectors that avoids preamplifier feedback resistor

    Microsoft Academic Search

    M. Sampietro; L. Fasoli; P. Rehak; L. Struder

    1995-01-01

    The paper describes the design and the performance of an original p-channel JFET embedded in the collecting anode of a silicon radiation detector. The choice of a p-channel transistor, whose gate-to-channel junction is forward biased by the leakage current from the detector, avoids the preamplifier feedback resistor and performs a continuous dc reset of the collected charge. The reported design,

  3. Purification and preparation of TlBr crystals for room temperature radiation detector applications

    Microsoft Academic Search

    Icimone B. Oliveira; Fábio E. Costa; José F. D. Chubaci; Margarida M. Hamada

    2004-01-01

    Thallium bromide (TlBr) is a semiconductor compound with a high atomic number and a wide bandgap, being a very promising material to be used as room temperature radiation detectors. In this work, commercial TlBr powder was used for growing crystals for detector applications. To reduce impurities, this material was purified by the zone refining technique. Trace impurities at ppb\\/ppm level

  4. Radiation pressure induced instabilities in laser interferometric detectors of gravitational waves

    Microsoft Academic Search

    A. Pai; S. V. Dhurandhar; P. Hello; J.-Y. Vinet

    2000-01-01

    The large scale interferometric gravitational wave detectors consist of Fabry-Perot cavities operating at very high powers\\u000a ranging from tens of kW to MW for next generations. The high powers may result in several nonlinear effects which would affect\\u000a the performance of the detector. In this paper, we investigate the effects of radiation pressure, which tend to displace the\\u000a mirrors from

  5. Network deployment of radiation detectors with physics-based detection probability calculations

    Microsoft Academic Search

    Nedialko B. Dimitrov; Dennis P. Michalopoulos; David P. Morton; Michael V. Nehme; Feng Pan; Elmira Popova; Erich A. Schneider; Gregory G. Thoreson

    We describe a model for deploying radiation detectors on a transportation network consisting of two adversaries: a nuclear-material\\u000a smuggler and an interdictor. The interdictor first installs the detectors. These installations are transparent to the smuggler,\\u000a and are made under an uncertain threat scenario, which specifies the smuggler’s origin and destination, the nature of the\\u000a material being smuggled, the manner in

  6. Low Noise Junction Field Effect Transistors in a Silicon Radiation Detector Technology

    Microsoft Academic Search

    Gian-Franco Dalla Betta; Maurizio Boscardin; F. Fenotti; L. Pancheri; C. Piemonte; L. Ratti; N. Zorzi

    2006-01-01

    We report on n-channel Junction Field Effect Transistors fabricated on high resistivity silicon by means of a specially tailored radiation detector technology. This research activity is being carried out in the framework of a project aiming at the integration of read-out circuits in the same detector substrate. Possible applications are in the field of medical\\/industrial imaging, space and high energy

  7. Modeling of characteristics of ionizing radiation detector based on AlGaAs-GaAs heterostructure

    Microsoft Academic Search

    G. I. Ayzenshtat; D. Y. Mokeev; O. P. Tolbanov; V. A. Khan

    2002-01-01

    Calculations of parameters of an ionizing radiation detector on the basis of the transistor heterostructure n(AlGaAs)-p+(GaAs)-n-(GaAs) have been carried out. The parameters of the structure have been optimized to achieve a maximum amplification factor at a minimum density of a collector current. It has been shown that in dynamics, when the detector is connected as a phototransistor with the broken

  8. Modeling of characteristics of ionizing radiation detector based on AlGaAs–GaAs heterostructure

    Microsoft Academic Search

    G. I Ayzenshtat; D. Y Mokeev; O. P Tolbanov; V. A Khan

    2002-01-01

    Calculations of parameters of an ionizing radiation detector on the basis of the transistor heterostructure n(AlGaAs)–p+(GaAs)–n?(GaAs) have been carried out. The parameters of the structure have been optimized to achieve a maximum amplification factor at a minimum density of a collector current. It has been shown that in dynamics, when the detector is connected as a phototransistor with the broken

  9. Radiation damage due to NIEL in GaAs particle detectors

    Microsoft Academic Search

    A. Chilingarov; J. S Meyer; T. Sloan

    1997-01-01

    The Non-Ionizing Energy Loss (NIEL) for fast neutrons, protons and pions in GaAs has been estimated from published calculations. The values are then used to search for a correlation between the observed reduction of charge collection efficiency (CCE) in GaAs particle detectors with the radiation dose from NIEL. A correlation is demonstrated to be present for detectors made from a

  10. Radiation detector made of a diamond single crystal grown by a chemical vapor deposition method

    Microsoft Academic Search

    J. H. Kaneko; T. Tanaka; T. Imai; Y. Tanimura; M. Katagiri; T. Nishitani; H. Takeuchi; T. Sawamura; T. Iida

    2003-01-01

    The first investigation of a radiation detector made of a diamond single crystal grown by a chemical vapor deposition (CVD) method was successfully carried out. The diamond single crystal, having a size of 2.0×2.0×0.7mm3, was grown by the CVD method and then applied to the detector. The CVD method was able to reduce nitrogen and boron impurities in diamond crystals

  11. Effect of extreme radiation fluences on parameters of SiC nuclear particle detectors

    Microsoft Academic Search

    A. M. Ivanov; A. A. Lebedev; N. B. Strokan

    2006-01-01

    Detectors based on modern CVD-grown films were irradiated with 8 MeV protons at a fluence of 3 1014 cm?2. The concentration of primary radiation defects was ?1017 cm?3, which is three orders of magnitude higher than the concentration of the initially present uncompensated donors. The resulting\\u000a deep compensation of SiC enabled measurements of detector parameters in two modes: under reverse

  12. PTOSL response of commercial Al2O3:C detectors to ultraviolet radiation.

    PubMed

    Gronchi, Claudia C; Caldas, Linda V E

    2013-04-01

    The photo-transferred optically stimulated luminescence (PTOSL) technique using Al2O3:C detectors has been suggested as a good option for ultraviolet (UV) radiation dosimetry. The objective of this work was to study the PTOSL response of Al2O3:C InLight detectors and the OSL microStar reader of Landauer. The parameters such as radiation pre-dose, optical treatment time and UV illumination time were determined. The detectors presented a satisfactory stimulus of PTOSL signals when they were subjected to a preconditioning procedure with gamma radiation (1 Gy pre-dose), 30 min of optical treatment (to empty the shallow traps) and 30 min of UV illumination from an artificial source. PMID:22887115

  13. A transition radiation detector for RHIC featuring accurate tracking and dE/dx particle identification

    SciTech Connect

    O`Brien, E.; Lissauer, D.; McCorkle, S.; Polychronakos, V.; Takai, H. [Brookhaven National Lab., Upton, NY (United States); Chi, C.Y.; Nagamiya, S.; Sippach, W.; Toy, M.; Wang, D.; Wang, Y.F.; Wiggins, C.; Willis, W. [Columbia Univ., New York, NY (United States); Cherniatin, V.; Dolgoshein, B. [Moscow Institute of Physics and Engineering, (Russian Federation); Bennett, M.; Chikanian, A.; Kumar, S.; Mitchell, J.T.; Pope, K. [Yale Univ., New Haven, CT (United States)

    1991-12-31

    We describe the results of a test ran involving a Transition Radiation Detector that can both distinguish electrons from pions which momenta greater titan 0.7 GeV/c and simultaneously track particles passing through the detector. The particle identification is accomplished through a combination of the detection of Transition Radiation from the electron and the differences in electron and pion energy loss (dE/dx) in the detector. The dE/dx particle separation is most, efficient below 2 GeV/c while particle ID utilizing Transition Radiation effective above 1.5 GeV/c. Combined, the electron-pion separation is-better than 5 {times} 10{sup 2}. The single-wire, track-position resolution for the TRD is {approximately}230 {mu}m.

  14. Review on the characteristics of radiation detectors for dosimetry and imaging.

    PubMed

    Seco, Joao; Clasie, Ben; Partridge, Mike

    2014-10-21

    The enormous advances in the understanding of human anatomy, physiology and pathology in recent decades have led to ever-improving methods of disease prevention, diagnosis and treatment. Many of these achievements have been enabled, at least in part, by advances in ionizing radiation detectors. Radiology has been transformed by the implementation of multi-slice CT and digital x-ray imaging systems, with silver halide films now largely obsolete for many applications. Nuclear medicine has benefited from more sensitive, faster and higher-resolution detectors delivering ever-higher SPECT and PET image quality. PET/MR systems have been enabled by the development of gamma ray detectors that can operate in high magnetic fields. These huge advances in imaging have enabled equally impressive steps forward in radiotherapy delivery accuracy, with 4DCT, PET and MRI routinely used in treatment planning and online image guidance provided by cone-beam CT. The challenge of ensuring safe, accurate and precise delivery of highly complex radiation fields has also both driven and benefited from advances in radiation detectors. Detector systems have been developed for the measurement of electron, intensity-modulated and modulated arc x-ray, proton and ion beams, and around brachytherapy sources based on a very wide range of technologies. The types of measurement performed are equally wide, encompassing commissioning and quality assurance, reference dosimetry, in vivo dosimetry and personal and environmental monitoring. In this article, we briefly introduce the general physical characteristics and properties that are commonly used to describe the behaviour and performance of both discrete and imaging detectors. The physical principles of operation of calorimeters; ionization and charge detectors; semiconductor, luminescent, scintillating and chemical detectors; and radiochromic and radiographic films are then reviewed and their principle applications discussed. Finally, a general discussion of the application of detectors for x-ray nuclear medicine and ion beam imaging and dosimetry is presented. PMID:25229250

  15. Internal Electric Field Behavior of Cadmium Zinc Telluride Radiation Detectors Under High Carrier Injection

    SciTech Connect

    Yang, G.; Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Hossain, A.; Kim, K.H.; Gul, R.; and James, R.B.

    2010-10-26

    The behavior of the internal electric-field of nuclear-radiation detectors substantially affects the detector's performance. We investigated the distribution of the internal field in cadmium zinc telluride (CZT) detectors under high carrier injection. We noted the build-up of a space charge region near the cathode that produces a built-in field opposing the applied field. Its presence entails the collapse of the electric field in the rest of detector, other than the portion near the cathode. Such a space-charge region originates from serious hole-trapping in CZT. The device's operating temperature greatly affects the width of the space-charge region. With increasing temperature from 5 C to 35 C, its width expanded from about 1/6 to 1/2 of the total depth of the detector.

  16. Gamma-ray escape peak characteristics of radiation-damaged reverse-electrode germanium coaxial detectors

    NASA Astrophysics Data System (ADS)

    Pehl, Richard H.; Hull, Ethan L.; Madden, Norman W.; Xing, Jingshu; Friesel, Dennis L.

    1996-02-01

    A comparison of the characteristics of full-energy gamma-ray peaks and their corresponding escape peaks when high energy photons interact in radiation damaged reverse-electrode (n-type) germanium coaxial detectors is presented. Coaxial detector geometry is the dominant factor, causing charge collection to be dramatically better for interactions occurring near the outer periphery of the detector as well as increasing of the probability of escape events occurring in this region. It follows that the resolution of escape peaks is better than that of ordinary gamma-ray peaks. This is experimentally verified. A nearly identical but undamaged detector exhibited significant Doppler broadening of single escape peaks. Because double escape events preferentially occur at outer radii, energy shifts of double escape reflect extremely small amounts of charge trapping in undamaged detectors.

  17. Radiation damage and charge collection effects in Si(Li) gamma-ray detectors

    NASA Astrophysics Data System (ADS)

    Hull, Ethan L.; Pehl, Richard H.; Tindall, Craig; Luke, Paul N.; Kurfess, James D.

    2003-01-01

    The spectroscopy performance of 6-mm thick Si(Li) planar detectors was studied as a function of operating temperature and electric field. The energy resolution of the 662-keV gamma-ray peak from a 137Cs source was used to monitor the spectroscopy performance of the detectors. The efficiency, depletion voltage, leakage current, and noise were also monitored. The effects of radiation damage caused by 200-MeV protons were studied to determine the viability of operation in space. Four detectors, two maintained at 88 K and two maintained at 212 K, were irradiated to a fluence of 8.7×10 8 p/cm 2. No effects were observed. The two detectors irradiated at 212 K were subsequently irradiated with an additional 8.7×10 9 p/cm 2, again at 212 K. These detectors then exhibited slight energy resolution degradation. No other radiation damage effects were observed. The resolution degradation increased at higher operating temperature and decreased with higher electric field. Cycling the detectors to room temperature for 14 h eliminated the resolution degradation. The resolution of these detectors is limited by the combination of ballistic deficit and parallel noise in the ˜220 K range. A significant decrease in the gamma-ray peak count rate, almost certainly caused by surface channel effects, was the most dramatic temperature-dependent effect observed.

  18. Beam test results with a reduced scale Silicon Transition Radiation Detector prototype

    NASA Astrophysics Data System (ADS)

    Brigida, M.; Caliandro, G. A.; Favuzzi, C.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Loparco, F.; Marangelli, B.; Mazziotta, M. N.; Mirizzi, N.; Monte, C.; Rainò, S.; Spinelli, P.

    2007-07-01

    This paper shows the results of a beam test campaign performed in September 2006 at the CERN-PS T9 beam facility with a reduced scale prototype of a silicon transition radiation detector (SiTRD). The detector prototype has been exposed to an electron-pion beam with momenta up to 10 GeV/c and has been tested with different kinds of radiators. These results integrate the ones obtained in a previous beam test, that are illustrated in Brigida et al. [Nucl. Instr. and Meth. A 564 (2006) 115].

  19. Pulse height distribution and radiation tolerance of CVD diamond detectors

    Microsoft Academic Search

    W. Adam; E. Berdermann; P. Bergonzo; G. Bertuccio; F. Bogani; E. Borchi; A. Brambilla; M. Bruzzi; C. Colledani; J. Conway; P. Dangelo; W. Dabrowski; P. Delpierre; A. Deneuville; W. Dulinski; B. van Eijk; A. Fallou; F. Fizzotti; F. Foulon; M. Friedl; K. K. Gan; E. Gheeraert; E. Grigoriev; G. Hallewell; S. Han; F. Hartjes; J. Hrubec; D. Husson; H. Kagan; D. Kania; J. Kaplon; C. Karl; R. Kass; M. Krammer; A. Logiudice; R. Lu; C. Manfredotti; D. Meier; M. Mishina; L. Moroni; A. Oh; L. S. Pan; M. Pernicka; A. Peitz; S. Pirollo; P. Polesello; M. Procario; J. L. Riester; S. Roe; L. Rousseau; A. Rudge; J. Russ; S. Sala; M. Sampietro; S. Schnetzer; S. Sciortino; H. Stelzer; R. Stone; B. Suter; R. J. Tapper; R. Tesarek; M. Trawick; W. Trischuk; D. Tromson; E. Vittone; A. M. Walsh; R. Wedenig; P. Weilhammer; C. White; W. Zeuner; M. Zoeller; A. Fenyvesi; J. Molnar; D. Sohler

    2000-01-01

    The paper reviews measurements of the radiation tolerance of CVD diamond for irradiation with 24GeV\\/c protons, 300MeV\\/c pions and 1MeV neutrons. For proton and neutron irradiation, the measured charge signal spectrum is compared with the spectrum calculated by a model. Irradiation by particles causes radiation damage leading to a decrease of the charge signal. However, both the measurements and the

  20. Functional characterization of a high-gain BJT radiation detector

    Microsoft Academic Search

    Giovanni Batignani; Stefano Bettarini; Mario Bondioli; Maurizio Boscardin; Luciano Bosisio; Gian-Franco Dalla Betta; Selenia Dittongo; Francesco Forti; Gabriele Giacomini; Marcello A. Giorgi; Paolo Gregori; Claudio Piemonte; Irina Rachevskaia; Sabina Ronchin; Nicola Zorzi

    2005-01-01

    n-p-n bipolar phototransistors have been designed and fabricated on high-resistivity silicon substrates. A technology featuring a double implant for the emitter allowed us to obtain a typical current gain of about 600. The device has been tested with ? particles from a 239Pu source, ? particles from 90Sr, and X-rays from 241Am using a simple experimental setup, where the detector

  1. Role of zinc in CdZnTe radiation detectors

    Microsoft Academic Search

    Muren Chu; Sevag Terterian; David Ting

    2004-01-01

    CdZnTe (CZT) crystals grown with Zn compositions of 0%, 10%, 15%, and 20% have been grown and detectors have been produced. Infrared transmissions measured on the wafers sliced from these crystals show that as the Zn composition increases, there is a reduction in the transmission toward longer wavelengths, indicating the existence of an increasing amount of larger Te-inclusions. For producing

  2. An advanced SiC nuclear radiation detector

    Microsoft Academic Search

    S. Seshadri; A. R. Dulloo; F. H. Ruddy

    1997-01-01

    This paper reports low noise, high charge collection efficiency, resolution, room temperature, self-biased operation of 3-8 ?m thick, epitaxially grown, SiC Schottky and pn junction diode detectors fabricated on n+ 4H-SiC substrates. These devices are also shown, for the first time, to have a linear gamma ray response. The thin active region used not only eliminates the problems with material

  3. [Effects of ionizing radiation on scintillators and other particle detectors]. Conference summary

    SciTech Connect

    Proudfoot, J.

    1992-09-01

    It is my task to summarise the great variety of topics (covering a refreshing mix of physics, chemistry and technology) presented at this conference, which has focused on the effects of ionising radiation on scintillators and other particle detectors. One of the reasons and the central interest of many of the participants was the use of such detectors in experiments at two future large hadron colliders: the Superconducting Super Collider to be operating outside of Dallas in the United States by the turn of the decade and its European counterpart the Large Hadron Collider to be operating outside of Geneva in Switzerland on a similar time scale. These accelerators are the ``apple of the high energy physicist`s eye.`` Their goal is to uncover the elusive Higgs particle and thereby set the cornerstone in our current knowledge of elementary particle interactions. This is the Quest, and from this lofty height the presentations rapidly moved on to the specific questions of experimental science: how such an experiment is carried out; why radiation damage is an issue; how radiation damage affects detectors; which factors affect radiation damage characteristics; which factors are not affected by radiation damage; and how better detectors may be constructed. These were the substance of this conference.

  4. Characterization of Silicon Photomultiplier Detectors using Cosmic Radiation

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    The silicon photomultiplier light detector has gained a lot of attention lately in fields such as particle physics, astrophysics, and medical physics. Its popularity stems from its lower cost, compact size, insensitivity to magnetic fields, and its excellent ability to distinguish a quantized number of photons. They are normally operated at room temperature and biased above their breakdown voltages. As such, they may also exhibit properties that may hinder their optimal operation which include a thermally induced high dark count rate, after pulse effects, and cross talk from photons in nearby pixels. At this poster session, we describe our data analysis and our endeavor to characterize the multipixel photon counter (MPPC) detectors from Hamamatsu under different bias voltages and temperature conditions. Particularly, we describe our setup which uses cosmic rays to induce scintillation light delivered to the detector by wavelength shifting optical fibers and the use of a fast 1 GHz waveform sampler, the domino ring sampler (DRS4) digitizer board. Department of Education grant number P031S90007.

  5. Capture of carriers by impurity clouds in germanium nuclear-radiation detectors

    Microsoft Academic Search

    V. V. Voronkov; G. I. Voronkova; S. G. Danengirsh; B. V. Zubov; V. P. Kalinushkin; T. M. Murina; E. A. Petrova; A. M. Prokhorov; N. B. Strokan; O. P. Chikalova-Luzina

    1982-01-01

    A correlation between the intensity of low-angle scattering of COâ laser radiation by impurity clouds of radius a = 6--9 ..mu.. and with an average charge loss factor lambda-bar was observed in nuclear-radiation detectors made of high-purity germanium. The nature of this effect was explained by considering the interaction of an impurity cloud with carriers drifting in the electric field

  6. Comprehensive modeling of bulk-damage effects in silicon radiation detectors

    Microsoft Academic Search

    Daniele Passeri; Paolo Ciampolini; Gian Mario Bilei; Francesco Moscatelli

    2001-01-01

    In this paper, the issue of numerical modeling of radiation-damaged silicon devices is discussed, with reference to radiation detectors employed in high-energy physics experiments. Since the actual physical picture is far too complex to be accounted for at a first-principle (i.e., defect kinetics) level and not yet fully understood, a hierarchical approach has been followed looking for a suitable approximation

  7. MOS-transistor radiation detectors and X-ray dose-enhancement effects

    Microsoft Academic Search

    L. D. Posey; T. F. Wrobel; D. C. Evans; W. Beezhold; J. G. Kelly; C. J. MacCallum; F. N. Coppage; T. F. Luera; A. J. Smith

    1985-01-01

    Sandia National Laboratory (SNL) CMOS IC dose detectors and 3N161 MOS Transistors were evaluated as pulsed X-radiation dosimeters and used as monitors to measure dose-enhancement effects. Measurements were made in the photon environments from the HydraMITE II, SPR III, MBS and PITHON radiation sources. The dosimetric evaluation data suggest that the 3N161 MOS transistors are useful dosimeters for measuring flash

  8. MOS-transistor radiation detectors and x-ray dose-enhancement effects

    Microsoft Academic Search

    L. D. Posey; T. F. Wrobel; D. C. Evans; W. Beezhold; J. G. Kelly; C. J. MacCallum; F. N. Coppage; T. F. Luera; A. J. Smith

    1985-01-01

    Sandia National Laboratory (SNL) CMOS IC dose detectors and 3N161 MOS Transistors were evaluated as pulsed x-radiation dosimeters and used as monitors to measure dose-enhancement effects. Measurements were made in the photon environments from the HydraMITE II, SPR III, MBS and PITHON radiation sources. The dosimetric evaluation data suggest that the 3N161 MOS transistors are useful dosimeters for measuring flash

  9. Feasibility study of a plasma display-like radiation detector for X-ray imaging.

    PubMed

    Eom, Sangheum; Shin, Hyoungsup; Kang, Jungwon; Lee, Hakjae; Lee, Kisung

    2012-01-01

    In this study we have investigated a 2-dimensional gas type detector based on plasma display technology as a candidate for the flat-panel radiation detector. By using the Garfield code, the dependence of X-ray absorption and multiplication on gas composition, cell gap and electric field were examined. Considering the simulation results, three prototype detectors were designed and fabricated. The performance of these detectors was evaluated by measuring the collected charge density, dark current density and sensitivity. The collected charge had the highest value at a condition when Xe 100% and 2.8 mm gap was 108.8 nC/cm² at 1000 V. The dark current of the same detector was varied from 0.0095 to 0.10 nA/cm² and about a fourth of the dark current density of a-Se based detector was at the bias range of 100-1000 V. The sensitivity of Xe 100% and 2.8 mm detector was 0.20 nC/mR·cm² at 0.36 V/um. It is about a tenth lower than that of a-Se based detector at 10 V/um. PMID:22948349

  10. On the problem of the radiation hardness of SiC nuclear radiation detectors at high working temperatures

    SciTech Connect

    Ivanov, A. M., E-mail: Alexandr.Ivanov@mail.ioffe.ru; Sadokhin, A. V.; Strokan, N. B.; Lebedev, A. A. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation)

    2011-10-15

    Owing to the radiation-induced pronounced conductivity compensation in silicon carbide, carrier localization (trapping) prevails over recombination in capture of nonequilibrium carriers. This makes it possible, by raising the temperature, to reduce the time of carrier retention by a trapping center to values shorter than the duration of signal shaping by electronic circuits. For structural defects created by 6.5-MeV protons, the temperature excluding degradation of the detector signal via carrier localization is estimated. The values of the appearing generation current the noise of which can restrict the operation of a detector in the spectrometric mode are determined.

  11. High-efficiency scintillation detector for combined of thermal and fast neutrons and gamma radiation

    DOEpatents

    Chiles, Marion M. (Knoxville, TN); Mihalczo, John T. (Oak Ridge, TN); Blakeman, Edward D. (Oak Ridge, TN)

    1989-01-01

    A scintillation based radiation detector for the combined detection of thermal neutrons, high-energy neutrons and gamma rays in a single detecting unit. The detector consists of a pair of scintillators sandwiched together and optically coupled to the light sensitive face of a photomultiplier tube. A light tight radiation pervious housing is disposed about the scintillators and a portion of the photomultiplier tube to hold the arrangement in assembly and provides a radiation window adjacent the outer scintillator through which the radiation to be detected enters the detector. The outer scintillator is formed of a material in which scintillations are produced by thermal-neutrons and the inner scintillator is formed of a material in which scintillations are produced by high-energy neutrons and gamma rays. The light pulses produced by events detected in both scintillators are coupled to the photomultiplier tube which produces a current pulse in response to each detected event. These current pulses may be processed in a conventional manner to produce a count rate output indicative of the total detected radiation even count rate. Pulse discrimination techniques may be used to distinguish the different radiations and their energy distribution.

  12. High-efficiency scintillation detector for combined detection of thermal and fast neutrons and gamma radiation

    DOEpatents

    Chiles, M.M.; Mihalczo, J.T.; Blakeman, E.D.

    1987-02-27

    A scintillation based radiation detector for the combined detection of thermal neutrons, high-energy neutrons and gamma rays in a single detecting unit. The detector consists of a pair of scintillators sandwiched together and optically coupled to the light sensitive face of a photomultiplier tube. A light tight radiation pervious housing is disposed about the scintillators and a portion of the photomultiplier tube to hold the arrangement in assembly and provides a radiation window adjacent the outer scintillator through which the radiation to be detected enters the detector. The outer scintillator is formed of a material in which scintillations are produced by thermal-neutrons and the inner scintillator is formed of a material in which scintillations are produced by high-energy neutrons and gamma rays. The light pulses produced by events detected in both scintillators are coupled to the photomultiplier tube which produces a current pulse in response to each detected event. These current pulses may be processed in a conventional manner to produce a count rate output indicative of the total detected radiation event count rate. Pulse discrimination techniques may be used to distinguish the different radiations and their energy distribution.

  13. Method and system for determining depth distribution of radiation-emitting material located in a source medium and radiation detector system for use therein

    DOEpatents

    Benke, Roland R. (Helotes, TX); Kearfott, Kimberlee J. (Ann Arbor, MI); McGregor, Douglas S. (Ann Arbor, MI)

    2003-03-04

    A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder positioned so that its central axis is perpendicular to the upper surface of the large area source when positioned thereon. The collimator allows the detector to angularly sample the emitted radiation over many ranges of polar angles. This is done by forming the collimator as a single adjustable collimator or a set of collimator pieces having various possible configurations when connected together. In any one configuration, the collimator allows the detector to detect only the radiation emitted from a selected range of polar angles measured from the detector axis. Adjustment of the collimator or the detector therein enables the detector to detect radiation emitted from a different range of polar angles. The system further includes a signal processor for processing the signals from the detector wherein signals obtained from different ranges of polar angles are processed together to obtain a reconstruction of the radiation-emitting material as a function of depth, assuming, but not limited to, a spatially-uniform depth distribution of the material within each layer. The detector system includes detectors having different properties (sensitivity, energy resolution) which are combined so that excellent spectral information may be obtained along with good determinations of the radiation field as a function of position.

  14. A Cherenkov Radiation Detector with High Density Aerogels

    E-print Network

    Cremaldi, Lucien; Sonnek, Peter; Summers, Donald J; Reidy, Jim

    2009-01-01

    We have designed a threshold Cherenkov detector at the Rutherford-Appleton Laboratory to identify muons with momenta between 230 and 350 MeV/c. We investigated the properties of three aerogels for the design. The nominal indexes of refraction were n = 1.03, 1.07, 1.12, respectively. Two of the samples are of high density aerogel not commonly used for Cherenkov light detection. We present results of an examination of some optical properties of the aerogel samples and present basic test beam results.

  15. Development of radiation tolerant semiconductor detectors for the Super-LHC

    NASA Astrophysics Data System (ADS)

    Moll, M.; Adey, J.; Al-Ajili, A.; Alfieri, G.; Allport, P. P.; Artuso, M.; Assouak, S.; Avset, B. S.; Barabash, L.; Barcz, A.; Bates, R.; Biagi, S. F.; Bilei, G. M.; Bisello, D.; Blue, A.; Blumenau, A.; Boisvert, V.; Bolla, G.; Bondarenko, G.; Borchi, E.; Borrello, L.; Bortoletto, D.; Boscardin, M.; Bosisio, L.; Bowcock, T. J. V.; Brodbeck, T. J.; Broz, J.; Bruzzi, M.; Brzozowski, A.; Buda, M.; Buhmann, P.; Buttar, C.; Campabadal, F.; Campbell, D.; Candelori, A.; Casse, G.; Cavallini, A.; Charron, S.; Chilingarov, A.; Chren, D.; Cindro, V.; Collins, P.; Coluccia, R.; Contarato, D.; Coutinho, J.; Creanza, D.; Cunningham, W.; Dalla Betta, G.-F.; Dawson, I.; de Boer, W.; De Palma, M.; Demina, R.; Dervan, P.; Dittongo, S.; Dolezal, Z.; Dolgolenko, A.; Eberlein, T.; Eremin, V.; Fall, C.; Fasolo, F.; Fizzotti, F.; Fleta, C.; Focardi, E.; Forton, E.; Fretwurst, E.; Garcia, C.; Garcia-Navarro, J. E.; Gaubas, E.; Genest, M.-H.; Gill, K. A.; Giolo, K.; Glaser, M.; Goessling, C.; Golovine, V.; González Sevilla, S.; Gorelov, I.; Goss, J.; Gouldwell Bates, A.; Grégoire, G.; Gregori, P.; Grigoriev, E.; Grillo, A. A.; Groza, A.; Guskov, J.; Haddad, L.; Härkönen, J.; Hauler, F.; Hoeferkamp, M.; Hönniger, F.; Horazdovsky, T.; Horisberger, R.; Horn, M.; Houdayer, A.; Hourahine, B.; Hughes, G.; Ilyashenko, I.; Irmscher, K.; Ivanov, A.; Jarasiunas, K.; Johansen, K. M. H.; Jones, B. K.; Jones, R.; Joram, C.; Jungermann, L.; Kalinina, E.; Kaminski, P.; Karpenko, A.; Karpov, A.; Kazlauskiene, V.; Kazukauskas, V.; Khivrich, V.; Khomenkov, V.; Kierstead, J.; Klaiber-Lodewigs, J.; Klingenberg, R.; Kodys, P.; Kohout, Z.; Korjenevski, S.; Koski, M.; Kozlowski, R.; Kozodaev, M.; Kramberger, G.; Krasel, O.; Kuznetsov, A.; Kwan, S.; Lagomarsino, S.; Lassila-Perini, K.; Lastovetsky, V.; Latino, G.; Lazanu, S.; Lazanu, I.; Lebedev, A.; Lebel, C.; Leinonen, K.; Leroy, C.; Li, Z.; Lindström, G.; Linhart, V.; Litovchenko, A.; Litovchenko, P.; Lo Giudice, A.; Lozano, M.; Luczynski, Z.; Luukka, P.; Macchiolo, A.; Makarenko, L. F.; Mandi?, I.; Manfredotti, C.; Manna, N.; Marti i Garcia, S.; Marunko, S.; Mathieson, K.; Melone, J.; Menichelli, D.; Messineo, A.; Metcalfe, J.; Miglio, S.; Mikuž, M.; Miyamoto, J.; Monakhov, E.; Moscatelli, F.; Naoumov, D.; Nossarzewska-Orlowska, E.; Nysten, J.; Olivero, P.; OShea, V.; Palviainen, T.; Paolini, C.; Parkes, C.; Passeri, D.; Pein, U.; Pellegrini, G.; Perera, L.; Petasecca, M.; Piemonte, C.; Pignatel, G. U.; Pinho, N.; Pintilie, I.; Pintilie, L.; Polivtsev, L.; Polozov, P.; Popa, A.; Popule, J.; Pospisil, S.; Pozza, A.; Radicci, V.; Rafí, J. M.; Rando, R.; Roeder, R.; Rohe, T.; Ronchin, S.; Rott, C.; Roy, A.; Ruzin, A.; Sadrozinski, H. F. W.; Sakalauskas, S.; Scaringella, M.; Schiavulli, L.; Schnetzer, S.; Schumm, B.; Sciortino, S.; Scorzoni, A.; Segneri, G.; Seidel, S.; Seiden, A.; Sellberg, G.; Sellin, P.; Sentenac, D.; Shipsey, I.; Sicho, P.; Sloan, T.; Solar, M.; Son, S.; Sopko, B.; Sopko, V.; Spencer, N.; Stahl, J.; Stolze, D.; Stone, R.; Storasta, J.; Strokan, N.; Sudzius, M.; Surma, B.; Suvorov, A.; Svensson, B. G.; Tipton, P.; Tomasek, M.; Tsvetkov, A.; Tuominen, E.; Tuovinen, E.; Tuuva, T.; Tylchin, M.; Uebersee, H.; Uher, J.; Ullán, M.; Vaitkus, J. V.; Velthuis, J.; Verbitskaya, E.; Vrba, V.; Wagner, G.; Wilhelm, I.; Worm, S.; Wright, V.; Wunstorf, R.; Yiuri, Y.; Zabierowski, P.; Zaluzhny, A.; Zavrtanik, M.; Zen, M.; Zhukov, V.; Zorzi, N.

    2005-07-01

    The envisaged upgrade of the Large Hadron Collider (LHC) at CERN towards the Super-LHC (SLHC) with a 10 times increased luminosity of 10 35 cm -2 s -1 will present severe challenges for the tracking detectors of the SLHC experiments. Unprecedented high radiation levels and track densities and a reduced bunch crossing time in the order of 10 ns as well as the need for cost effective detectors have called for an intensive R&D program. The CERN RD50 collaboration "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" is working on the development of semiconductor sensors matching the requirements of the SLHC. Sensors based on defect engineered silicon like Czochralski, epitaxial and oxygen enriched silicon have been developed. With 3D, Semi-3D and thin detectors new detector concepts have been evaluated and a study on the use of standard and oxygen enriched p-type silicon detectors revealed a promising approach for radiation tolerant cost effective devices. These and other most recent advancements of the RD50 collaboration are presented.

  16. Optimum pulse filters for radiation detectors and their parameters

    Microsoft Academic Search

    L. S. Gorn; M. V. Iovlev; B. I. Khazanov

    1972-01-01

    ABS>Calculations are given for the parameters of optimum pulse filters ; for radiation detection instruments. These filters guarantee minimum statistical ; measurement error at a given density function of the distribution of useful and ; back-round signals and signal frequency ratio. A equations are derived for the ; coefficient of reduction of the pulse frequency in the zone of filter

  17. Evaluation of high density DRAMs as a nuclear radiation detector

    Microsoft Academic Search

    H. P. Chou; T. C. Chou; T. H. Hau

    1997-01-01

    The research is based on the nuclear radiation induced soft error phenomenon associated with dynamic random access memory devices (DRAMs). Samples of 256 kbit and 1 Mbit decapped DRAMs from several manufacturers were exposed to standard alpha sources and showed a linear response with an intrinsic detection efficiency approaching 10%. Sensitivity studies were performed to evaluate the effects of DRAM

  18. Spectral and temperature correction of silicon photovoltaic solar radiation detectors

    Microsoft Academic Search

    J. J. Michalsky; R. Perez; L. Harrison; B. A. LeBaron

    1991-01-01

    Silicon photovoltaic sensors are an inexpensive alternative to standard thermopile sensors for the measurement of solar radiation. However, their temperature and spectral response render them less accurate for global horizontal irradiance and unsuitable for direct beam and diffuse horizontal irradiance unless they can be reliably corrected. A correction procedure for the rotating shadowband radiometer, which measures all three components, based

  19. Radiation detectors and sources enhanced with micro/nanotechnology

    NASA Astrophysics Data System (ADS)

    Whitney, Chad Michael

    The ongoing threat of nuclear terrorism presents major challenges to maintaining national security. Currently, only a small percentage of the cargo containers that enter America are searched for fissionable bomb making materials. This work reports on a multi-channel radiation detection platform enabled with nanoparticles that is capable of detecting and discriminating all types of radiation emitted from fissionable bomb making materials. Typical Geiger counters are limited to detecting only beta and gamma radiation. The micro-Geiger counter reported here detects all species of radiation including beta particles, gamma/X-rays, alpha particles, and neutrons. The multi-species detecting micro-Geiger counter contains a hermetically sealed and electrically biased fill gas. Impinging radiation interacts with tailored nanoparticles to release secondary charged particles that ionize the fill gas. The ionized particles collect on respectively biased electrodes resulting in a characteristic electrical pulse. Pulse height spectroscopy and radiation energy binning techniques can then be used to analyze the pulses to determine the specific radiation isotope. The ideal voltage range of operation for energy discrimination was found to be in the proportional region at 1000VDC. In this region, specific pulse heights for different radiation species resulted. The amplification region strength which determines the device sensitivity to radiation energy can be tuned with the electrode separation distance. Considerable improvements in count rates were achieved by using the charge conversion nanoparticles with the highest cross sections for particular radiation species. The addition of tungsten nanoparticles to the microGeiger counter enabled the device to be four times more efficient at detecting low level beta particles with a dose rate of 3.2uR/hr (micro-Roentgen per hour) and just under three times more efficient than an off the shelf Geiger counter. The addition of lead nanoparticles enabled the gamma/X-ray microGeiger counter channel to be 28 times more efficient at detecting low level gamma rays with a dose rate of 10uR/hr when compared to a device without nanoparticles. The addition of 10B nanoparticles enabled the neutron microGeiger counter channel to be 17 times more efficient at detecting neutrons. The device achieved a neutron count rate of 9,866 counts per minute when compared to a BF3 tube which resulted in a count rate of 9,000 counts per minute. By using a novel micro-injection ceramic molding and low temperature (950°C) silver paste metallizing process, the batch fabrication of essentially disposable micro-devices can be achieved. This novel fabrication technique was then applied to a MEMS neutron gun and water spectroscopy device that also utilizes the high voltage/temperature insulating packaging.

  20. Preliminary Results from an Investigation into Nanostructured Nuclear Radiation Detectors for Non-Proliferation Applications

    SciTech Connect

    ,

    2012-10-01

    In recent years, the concept of embedding composite scintillators consisting of nanosized inorganic crystals in an organic matrix has been actively pursued. Nanocomposite detectors have the potential to meet many of the homeland security, non-proliferation, and border and cargo-screening needs of the nation and, by virtue of their superior nuclear identification capability over plastic, at roughly the same cost as plastic, have the potential to replace all plastic detectors. Nanocomposites clearly have the potential of being a gamma ray detection material that would be sensitive yet less expensive and easier to produce on a large scale than growing large, whole crystals of similar sensitivity. These detectors would have a broad energy range and a sufficient energy resolution to perform isotopic identification. The material can also be fabricated on an industrial scale, further reducing cost. This investigation focused on designing and fabricating prototype core/shell and quantum dot (QD) detectors. Fourteen core/shell and four QD detectors, all with the basic consistency of a mixture of nanoparticles in a polymer matrix with different densities of nanoparticles, were prepared. Nanoparticles with sizes <10 nm were fabricated, embedded in a polystyrene matrix, and the resultant scintillators’ radiation detector properties were characterized. This work also attempted to extend the gamma energy response on both low- and high-energy regimes by demonstrating the ability to detect low-energy and high-energy gamma rays. Preliminary results of this investigation are consistent with a significant response of these materials to nuclear radiation.

  1. Semiconductor multiple-electrode detectors for measuring ionizing radiation at room temperature

    NASA Astrophysics Data System (ADS)

    Lingren, Clinton L.; Apotovsky, Boris A.; Butler, Jack F.; Conwell, Richard L.; Doty, F. Patrick; Friesenhahn, Stan J.; Oganesyan, A.; Pi, Bo; Zhao, S.

    1997-07-01

    Researchers at Digirad Corporation have developed an innovative method for eliminating the effects of hole trapping in radiation detectors made from compound semiconductors such as CdTe or CdZnTe. The technique involves no additional electronics. Working devices have been manufactured in a variety of configurations including imaging arrays. This paper presents results from some simple structures.

  2. The reduction of the leakage current of radiation detectors by a simple cap implantation process

    Microsoft Academic Search

    Dejun Han; Chuanmin Wang; Shuchen Du

    2001-01-01

    The depletion layer of PN junction of semiconductor radiation detectors usually spreads and reaches to the back side of the wafer while it spreads laterally to a distance comparable to the thickness of the wafer during operation. The area of the lateral spreading has a large fraction relative to the core active region, and an extra guard ring structure is

  3. On-line statistical processing of radiation detector pulse trains with time-varying count rates

    Microsoft Academic Search

    G. Apostolopoulos

    2008-01-01

    Statistical analysis is of primary importance for the correct interpretation of nuclear measurements, due to the inherent random nature of radioactive decay processes. This paper discusses the application of statistical signal processing techniques to the random pulse trains generated by radiation detectors. The aims of the presented algorithms are: (i) continuous, on-line estimation of the underlying time-varying count rate ?(t)

  4. Simple method for measuring the energy equivalent of the noise of semiconductor nuclear radiation detectors

    Microsoft Academic Search

    O. V. Zakharchuk; A. A. Ilin

    1973-01-01

    Translated from Prib. Tekn. Eksp.; 16: No. 4, 75-77(1973). A method ; is considered for determining the energy equivalent of the noise of semiconductor ; nuclear-radiation detectors which is based on calibrating a simplified ; measurement device consisting solely of a spectrometric preamplifier and a vacuum-; tube voltmeter. The method allows a considerable increase in the speed of the ;

  5. Developing Si(Li) nuclear radiation detectors by pulsed electric field treatment

    Microsoft Academic Search

    R. A. Muminov; S. A. Radzhapov; A. K. Saimbetov

    2009-01-01

    Fabrication of Si(Li) nuclear radiation detectors using lithium ion drift under the action of a pulsed electric field is considered. Optimum treatment regime parameters are determined, including the pulse amplitude, duration, and repetition rate. Experimental data are presented, which show that the ion drift in a pulsed electric field decreases the semiconductor bulk compensation time by a factor of two

  6. Paul Sellin, Radiation Imaging Group The role of defects on CdTe detector performance

    E-print Network

    Sellin, Paul

    Paul Sellin, Radiation Imaging Group The role of defects on CdTe detector performance P.J. Sellin1-destructive material characterisation techniques have been applied to CdTe wafers grown by the Travelling Heater Method Imaging Group PL mapping of whole CdTe wafers PL ( =819 nm) scan for two CdTe wafers, (left: wafer L700

  7. Performance of the Transition Radiation Detector of the PAMELA space mission

    Microsoft Academic Search

    M. Ambriola

    2002-01-01

    The performance of the Transition Radiation Detector (TRD) of the PAMELA telescope has been studied using beam test data and simulation tools. PAMELA is a satellite—borne magnetic spectrometer designed to measure particles and antiparticles spectra in cosmic rays. The particle identification at high energy will be achieved by combining the measurements by the TRD and a silicon—tungsten imaging calorimeter. The

  8. THE AMS-02 TRANSITION RADIATION DETECTOR FOR THE INTERNATIONAL SPACE STATION

    E-print Network

    Roma "La Sapienza", Università di

    1 THE AMS-02 TRANSITION RADIATION DETECTOR FOR THE INTERNATIONAL SPACE STATION A. BARTOLONI I The Alpha Magnetic Spectrometer (AMS-02) is a large experiment in the International Space Station (ISS on the International Space Station (ISS) to measure primary cosmic ray spectra in space [1]. A key element for dark

  9. Concept of Double Peak electric field distribution in the development of radiation hard silicon detectors

    Microsoft Academic Search

    E. Verbitskaya; V. Eremin; Z. Li; J. Härkönen; M. Bruzzi

    2007-01-01

    The concept of Double Peak (DP) electric field distribution is considered for the analysis of operational characteristics of irradiated silicon detectors. The key point of the model is trapping of equilibrium carriers to the midgap energy levels of radiation-induced defects, which leads to a non-uniform distribution of space charge concentration with positively and negatively charged regions adjacent to the p+

  10. Performance of CdZnTe geometrically weighted semiconductor Frisch grid radiation detectors

    Microsoft Academic Search

    D. S. McGregor; R. A. Rojeski

    1999-01-01

    Semiconductor Frisch grid radiation detectors have been manufactured and tested with encouraging results. Resolution enhancement occurs as a result of combining the geometric weighting effect, the “small pixel” effect and the Frisch grid effect. The devices are operated at ambient temperature without any pulse shape correction, rejection and compensation techniques. The new devices are manufactured from CdZnTe and do not

  11. Influence of zone purification process on TlBr crystals for radiation detector fabrication

    Microsoft Academic Search

    Keitaro Hitomi; Toshiyuki Onodera; Tadayoshi Shoji

    2007-01-01

    Thallium bromide (TlBr) is a wide gap compound semiconductor and is a promising material for fabrication of nuclear radiation detectors. In this study, the conventional zone refining method was employed to reduce the concentration of impurities in the TlBr crystals. In order to evaluate the efficiency of the zone purification, the zone purification process was repeated up to 300 times.

  12. Recent Results Obtained with High Field, Internally Amplifying Semiconductor Radiation Detectors

    Microsoft Academic Search

    Gerald C. Huth

    1966-01-01

    Characterization of the gallium diffused junctions found useful as amplifying radiation detectors indicate a rather surprising window-junction depth relationship. The window, at only the self bias of the junction, has been measured to be a micron or so although the junction depth is ~50 microns. This is a result of the unusual diffusion process used - diffusion to 75 microns

  13. A new thermal radiation detector using optical heterodyne detection of absorbed energy

    NASA Technical Reports Server (NTRS)

    Davis, C. C.; Petuchowski, S. J.

    1983-01-01

    The operating principles of a new kind of room-temperature thermal radiation detector are described. In this device modulated light heats a gas, either directly or by conduction from a thin absorbing membrane, and the resultant change in density of the gas is detected by optical heterodyning. The performance of a membrane device of this kind agrees well with the predictions of theory.

  14. Using Ionizing Radiation Detectors. Module 11. Vocational Education Training in Environmental Health Sciences.

    ERIC Educational Resources Information Center

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on using ionizing radiation detectors. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) naming and telling the function…

  15. Low-cost cadmium zinc telluride radiation detectors based on electron-transport-only designs

    SciTech Connect

    B. A. Brunett; J. C. Lund; J. M. Van Scyoc; N. R. Hilton; E. Y. Lee; R. B. James

    1999-01-01

    The goal of this project was to utilize a novel device design to build a compact, high resolution, room temperature operated semiconductor gamma ray sensor. This sensor was constructed from a cadmium zinc telluride (CZT) crystal. It was able to both detect total radiation intensity and perform spectroscopy on the detected radiation. CZT detectors produced today have excellent electron charge carrier collection, but suffer from poor hole collection. For conventional gamma-ray spectrometers, both the electrons and holes must be collected with high efficiency to preserve energy resolution. The requirement to collect the hole carriers, which have relatively low lifetimes, limits the efficiency and performance of existing experimental devices. By implementing novel device designs such that the devices rely only on the electron signal for energy information, the sensitivity of the sensors for detecting radiation can be increased substantially. In this report the authors describe a project to develop a new type of electron-only CZT detector. They report on their successful efforts to design, implement and test these new radiation detectors. In addition to the design and construction of the sensors the authors also report, in considerable detail, on the electrical characteristics of the CZT crystals used to make their detectors.

  16. Investigation of efficient termination structure for improved breakdown properties of semiconductor radiation detectors

    Microsoft Academic Search

    D. Krizaj; D. Resnik; D. Vrtacnik; S. Amon; V. Cindro

    1998-01-01

    Efficiency of a new junction termination structure for improvement of breakdown properties of semiconductor radiation detectors is investigated. The structure consists of a diffused resistor winding around the active junction in a spiral fashion. The current flow through the spiral enables controlled potential distribution along the spiral turns and thus controlled depletion spreading from the main junction, efficiently preventing premature

  17. Monte Carlo modeling of fiber-scintillator flow-cell radiation detector geometry

    Microsoft Academic Search

    T. L. Rucker; H. H. Ross; G. K. Schweitzer

    1988-01-01

    A Monte Carlo computer calculation is described which models the geometric efficiency of a fiber-scintillator flow-cell radiation detector designed to detect radiolabeled compounds in liquid chromatography eluates. By using special mathematical techniques, an efficiency prediction with a precision of 1% is obtained after generating only 1000 random events. Good agreement is seen between predicted and experimental efficiency except for very

  18. Precise dose evaluation using a commercial phototransistor as a radiation detector

    Microsoft Academic Search

    L. A. P. Santos; F. R. Barros; J. A. Filho

    2006-01-01

    An experimental arrangement and a circuitry based on an NPN phototransistor-type silicon radiation detector have been used for evaluating the X-ray beam dose in the diagnostic range. The circuitry was built to allow alteration of the electric field in the phototransistor internal structure, with some devices that have an available base connection. By changing the transistor base bias it is

  19. Very high radiation detector for the LHC BLM system based on secondary electron emission

    Microsoft Academic Search

    Daniel Kramer; Bernd Dehning; Eva Barbara Holzer; Gianfranco Ferioli

    2007-01-01

    Beam loss monitoring (BLM) system plays a vital role in the active protection of the LHC accelerators elements. It should provide the number of particles lost from the primary hadron beam by measuring the radiation field induced by their interaction with matter surrounding the beam pipe. The LHC BLM system will use ionization chambers as standard detectors but in the

  20. Testing and Evaluation Protocol for Spectroscopic Personal Radiation Detectors (SPRDs) for Homeland

    E-print Network

    Perkins, Richard A.

    Testing and Evaluation Protocol for Spectroscopic Personal Radiation Detectors (SPRDs) for Homeland Security T&E Protocol N42.48, 2010 Version 1.02 #12;Table of Content 1. Scope .........................................................................................................3 #12;TEST AND EVALUATION PROTOCOL TEP NO. N42.48 PREPARED BY: DIV682 TITLE: Spectroscopic Personal

  1. Testing and Evaluation Protocol for Spectroscopic Personal Radiation Detectors (SPRDs) for Homeland

    E-print Network

    Testing and Evaluation Protocol for Spectroscopic Personal Radiation Detectors (SPRDs) for Homeland Security T&E Protocol N42.48, 2013 #12;Table of Content 1. Scope..........................................................................................................3 #12;TEST AND EVALUATION PROTOCOL TEP NO. N42.48 PREPARED BY: DIV682 TITLE: Spectroscopic Personal

  2. Comparison of cosmic rays radiation detectors on-board commercial jet aircraft.

    PubMed

    Kuban?ák, Ján; Ambrožová, Iva; Brabcová, Kate?ina Pachnerová; Jak?bek, Jan; Kyselová, Dagmar; Ploc, Ond?ej; Bemš, Július; Št?pán, Václav; Uchihori, Yukio

    2015-06-01

    Aircrew members and passengers are exposed to increased rates of cosmic radiation on-board commercial jet aircraft. The annual effective doses of crew members often exceed limits for public, thus it is recommended to monitor them. In general, the doses are estimated via various computer codes and in some countries also verified by measurements. This paper describes a comparison of three cosmic rays detectors, namely of the (a) HAWK Tissue Equivalent Proportional Counter; (b) Liulin semiconductor energy deposit spectrometer and (c) TIMEPIX silicon semiconductor pixel detector, exposed to radiation fields on-board commercial Czech Airlines company jet aircraft. Measurements were performed during passenger flights from Prague to Madrid, Oslo, Tbilisi, Yekaterinburg and Almaty, and back in July and August 2011. For all flights, energy deposit spectra and absorbed doses are presented. Measured absorbed dose and dose equivalent are compared with the EPCARD code calculations. Finally, the advantages and disadvantages of all detectors are discussed. PMID:25979739

  3. Silicon field-effect transistors as radiation detectors for the Sub-THz range

    SciTech Connect

    But, D. B., E-mail: but.dmitry@gmail.com; Golenkov, O. G.; Sakhno, N. V.; Sizov, F. F.; Korinets, S. V.; Gumenjuk-Sichevska, J. V.; Reva, V. P.; Bunchuk, S. G. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine)

    2012-05-15

    The nonresonance response of silicon metal-oxide-semiconductor field-effect transistors (Si-MOSFETs) with a long channel (1-20 {mu}m) to radiation in the frequency range 43-135 GHz is studied. The transistors are fabricated by the standard CMOS technology with 1-{mu}m design rules. The volt-watt sensitivity and the noise equivalent power (NEP) for such detectors are estimated with the calculated effective area of the detecting element taken into account. It is shown that such transistors can operate at room temperature as broadband direct detectors of sub-THz radiation. In the 4-5 mm range of wavelengths, the volt-watt sensitivity can be as high as tens of kV/W and the NEP can amount to 10{sup -11} - 10{sup -12}W/{radical}Hz . The parameters of detectors under study can be improved by the optimization of planar antennas.

  4. Dichroic filters to protect milliwatt far-infrared detectors from megawatt ECRH radiation

    SciTech Connect

    Bertschinger, G.; Oosterbeek, J. W. [Institut fuer Energieforschung-Plasmaphysik, Forschungszentrum Juelich, Association EURATOM-FZJ, Trilateral Euregio Cluster, 52425 Juelich (Germany); Endres, C. P.; Lewen, F. [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2008-10-15

    Dichroic filters have been used to shield effectively the far infrared (FIR) detectors at the interferometer/polarimeter on TEXTOR. The filters consist of metal foils with regular holes, the hole diameter, the mutual spacing and the thickness of the foils are chosen to transmit radiation at the design frequency with transmission >90%. The attenuation at the low frequency end of the bandpass filter is about 30 dB per octave, the high frequency transmission is between 20% and 40%. The filters have been used to block the stray radiation from the megawatt microwave heating beam to the detectors of the FIR interferometer, operating with power on the detector in the milliwatt range. If required, the low frequency attenuation can be still enhanced, without compromising the transmission in the passband. The FIR interferometer used for plasma density and position control is no longer disturbed by electromagnetic waves used for plasma heating.

  5. Dichroic filters to protect milliwatt far-infrared detectors from megawatt ECRH radiation.

    PubMed

    Bertschinger, G; Endres, C P; Lewen, F; Oosterbeek, J W

    2008-10-01

    Dichroic filters have been used to shield effectively the far infrared (FIR) detectors at the interferometer/polarimeter on TEXTOR. The filters consist of metal foils with regular holes, the hole diameter, the mutual spacing and the thickness of the foils are chosen to transmit radiation at the design frequency with transmission >90%. The attenuation at the low frequency end of the bandpass filter is about 30 dB per octave, the high frequency transmission is between 20% and 40%. The filters have been used to block the stray radiation from the megawatt microwave heating beam to the detectors of the FIR interferometer, operating with power on the detector in the milliwatt range. If required, the low frequency attenuation can be still enhanced, without compromising the transmission in the passband. The FIR interferometer used for plasma density and position control is no longer disturbed by electromagnetic waves used for plasma heating. PMID:19044527

  6. Operational Characteristics of SiC Diodes as Ionizing Radiation Detectors

    SciTech Connect

    De Napoli, M.; Raciti, G.; Rapisarda, E.; Sfienti, C. [Dipartimento di Fisica e Astronomia, Universita degli Studi di Catania, Via S. Sofia 64, 95123 Catania-Italy (Italy); INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Giacoppo, F. [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica, Universita degli Studi di Messina, Via Salita Sperone 31, I-98166 Messina (Italy)

    2009-12-02

    In order to explore the possibility of using SiC detectors in nuclear physics applications in extreme environments, the operational characteristics of 4H-SiC Schottky diodes with different dopant concentrations have been studied with {sup 12}C and {sup 16}O ions at various incident energies. The detector response has been investigated in term of linearity, energy resolution, signal rise-time and Charge Collection Efficiency as a function of the applied reverse bias and of the dopant concentration. Moreover, since one of the most promising properties of SiC detectors is their radiation hardness, the radiation damage, produced by irradiating SiC diodes with {sup 16}O ions at 35.2 MeV, has been evaluated by measuring the degradation of both the signal pulse-height and the energy resolution as a function of the {sup 16}O fluence.

  7. EFFECT OF SURFACE PREPARATION TECHNIQUE ON THE RADIATION DETECTOR PERFORMANCEOF CDZNTE

    SciTech Connect

    Duff, M

    2007-05-23

    Synthetic CdZnTe (CZT) semiconducting crystals are highly suitable for the room temperature-based detection of gamma radiation. The surface preparation of Au contacts on surfaces of CZT detectors is typically conducted after (1) polishing to remove artifacts from crystal sectioning and (2) chemical etching, which removes residual mechanical surface damage however etching results in a Te rich surface layer that is prone to oxidize. Our studies show that CZT surfaces that are only polished (as opposed to polished and etched) can be contacted with Au and will yield lower surface currents. Due to their decreased dark currents, these as-polished surfaces can be used in the fabrication of gamma detectors exhibiting a higher performance than polished and etched surfaces with relatively less peak tailing and greater energy resolution. CdZnTe or ''CZT'' crystals are attractive to use in homeland security applications because they detect radiation at room temperature and do not require low temperature cooling as with silicon- and germanium-based detectors. Relative to germanium and silicon detectors, CZT is composed of higher Z elements and has a higher density, which gives it greater ''stopping power'' for gamma rays making a more efficient detector. Single crystal CZT materials with high bulk resistivity ({rho}>10{sup 10} {Omega} x cm) and good mobility-lifetime products are also required for gamma-ray spectrometric applications. However, several factors affect the detector performance of CZT are inherent to the as grown crystal material such as the presence of secondary phases, point defects and the presence of impurities (as described in a literature review by R. James and researchers). These and other factors can limit radiation detector performance such as low resistivity, which causes a large electronic noise and the presence of traps and other heterogeneities, which result in peak tailing and poor energy resolution.

  8. Calibration of modified Liulin detector for cosmic radiation measurements on-board aircraft.

    PubMed

    Kyselová, D; Ambrožová, I; Krist, P; Kuban?ák, J; Uchihori, Y; Kitamura, H; Ploc, O

    2015-06-01

    The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them. Aircrew dosimetry is usually performed using special computer programs mostly based on results of Monte Carlo simulations. Contemporary, detectors are used mostly for validation of these computer codes, verification of effective dose calculations and for research purposes. One of such detectors is active silicon semiconductor deposited energy spectrometer Liulin. Output quantities of measurement with the Liulin detector are the absorbed dose in silicon D and the ambient dose equivalent H*(10); to determine it, two calibrations are necessary. The purpose of this work was to develop a calibration methodology that can be used to convert signal from the detector to D independently on calibration performed at Heavy Ion Medical Accelerator facility in Chiba, Japan. PMID:25979744

  9. Radiation detectors fabricated on high-purity GaAs epitaxial materials

    NASA Astrophysics Data System (ADS)

    Wu, X.; Kostamo, P.; Gädda, A.; Nenonen, S.; Riekkinen, T.; Härkönen, J.; Salonen, J.; Andersson, H.; Zhilyaev, Y.; Fedorov, L.; Eränen, S.; Mattila, M.; Lipsanen, H.; Prunnila, M.; Kalliopuska, J.; Oja, A.

    2014-12-01

    Epitaxial GaAs material shows a great potential in X-ray spectroscopy and radiography applications due to its high absorption efficiency and low defect density. Fabrication of pixel radiation detectors from high-purtity epitaxial GaAs has been developed further. The process is based on mesa etching for pixellisation and sputtering for metallization. The leakage currents of processed pad detectors are below 10 nA/cm2 at a reverse bias of 100 V and decrease exponentially with the temperature. Measurement with transient current technique (TCT) shows that electrons have a trapping time of 8 ns. Good spectroscopic result were obtained from both a pad detector and a hybridized Medipix GaAs detector.

  10. Gamma-Ray Escape Peak Characteristics of Radiation Damaged Reverse-Electrode Germanium Detectors

    NASA Astrophysics Data System (ADS)

    Hull, E. L.; Xing, J. S.; Friesel, D. L.; Pehl, R. H.; Madden, N. M.

    1996-05-01

    A comparison between the characteristics of escape peaks and ordinary, multiple Compton and photoelectrically interacting, full-energy gamma-ray peaks from radiation damaged reverse-electrode (n-type) germanium coaxial detectors is presented. Coaxial detector geometry is the dominant factor, causing charge collection to be dramatically better near the outer periphery of the detector as well as increasing the probability of escape events occurring in this region. It follows that the resolution of escape peaks is better than that of ordinary gamma-ray peaks. This is experimentally verified. However, a nearly identical but undamaged detector exhibited significant Doppler broadening of single escape peaks. Because double escape events preferentially occur at outer radii, energy shifts in double escape peaks reflect extremely small amounts of charge trapping.

  11. Digital configurable instrument for emulation of signals from radiation detectors.

    PubMed

    Abba, A; Caponio, F; Geraci, A

    2014-01-01

    The paper presents a digital instrument characterized by a specially designed architecture that is able to emulate in real time signals from a generic radiation detection system. The instrument is not a pulse generator of recorded shapes but a synthesizer of random pulses compliant to programmable statistics for height and starting time of events. Completely programmable procedures for emulation of noise, disturbances, and reference level variation are implemented. PMID:24517764

  12. Digital configurable instrument for emulation of signals from radiation detectors

    NASA Astrophysics Data System (ADS)

    Abba, A.; Caponio, F.; Geraci, A.

    2014-01-01

    The paper presents a digital instrument characterized by a specially designed architecture that is able to emulate in real time signals from a generic radiation detection system. The instrument is not a pulse generator of recorded shapes but a synthesizer of random pulses compliant to programmable statistics for height and starting time of events. Completely programmable procedures for emulation of noise, disturbances, and reference level variation are implemented.

  13. Digital configurable instrument for emulation of signals from radiation detectors

    SciTech Connect

    Abba, A.; Caponio, F.; Geraci, A. [Politecnico di Milano, Department of Electronics, Information and Bioengineering-DEIB, Milan 20133 (Italy)] [Politecnico di Milano, Department of Electronics, Information and Bioengineering-DEIB, Milan 20133 (Italy)

    2014-01-15

    The paper presents a digital instrument characterized by a specially designed architecture that is able to emulate in real time signals from a generic radiation detection system. The instrument is not a pulse generator of recorded shapes but a synthesizer of random pulses compliant to programmable statistics for height and starting time of events. Completely programmable procedures for emulation of noise, disturbances, and reference level variation are implemented.

  14. Quantum limits on resonant-mass gravitational-radiation detectors

    Microsoft Academic Search

    James Hollenhorst

    1979-01-01

    The methods of quantum detection theory are applied to a resonant-mass gravitational-radiation antenna. Quantum sensitivity limits are found which depend strongly on the quantum state in which the antenna is prepared. Optimum decision strategies and their corresponding sensitivities are derived for some important initial states. The linear detection limit (E\\/sub min\\/ approx. h..omega..) is shown to apply when the antenna

  15. Radiation tolerance of CVD diamond detectors for pions and protons

    Microsoft Academic Search

    W. Adam; E. Berdermann; P. Bergonzo; G. Bertuccio; F. Bogani; E. Borchi; A. Brambilla; M. Bruzzi; C. Colledani; J. Conway; P D’Angelo; W. Dabrowski; P. Delpierre; A. Deneuville; W. Dulinski; B van Eijk; A. Fallou; F. Fizzotti; F. Foulon; M. Friedl; K. K. Gan; E. Gheeraert; G. Hallewell; S. Han; F. Hartjes; J. Hrubec; D. Husson; H. Kagan; D. Kania; J. Kaplon; R. Kass; T. Koeth; M. Krammer; A. Logiudice; R. Lu; L mac Lynne; C. Manfredotti; D. Meier; M. Mishina; L. Moroni; J. Noomen; A. Oh; L. S Pan; M. Pernicka; A. Peitz; L. Perera; S. Pirollo; M. Procario; J. L Riester; S. Roe; L. Rousseau; A. Rudge; J. Russ; S. Sala; M. Sampietro; S. Schnetzer; S. Sciortino; H. Stelzer; R. Stone; B. Suter; R. J Tapper; R. Tesarek; W. Trischuk; D. Tromson; E. Vittone; A. M Walsh; R. Wedenig; P. Weilhammer; M. Wetstein; C. White; W. Zeuner; M. Zoeller

    2002-01-01

    The paper gives new results on the radiation tolerance of CVD diamond for irradiation with 300MeV\\/c pions and 24GeV\\/c protons. The measured charge signal spectrum is compared at several irradiation levels with the spectrum calculated by a model. Irradiation by particles causes damage leading to a decrease of the charge signal. However, both the measurements and the outcome from the

  16. Performance of bulk SiC radiation detectors

    Microsoft Academic Search

    W. Cunningham; A. Gouldwell; G. Lamb; J. Scott; K. Mathieson; P. Roy; R. Bates; P. Thornton; K. M Smith; R. Cusco; M. Glaser; M. Rahman

    2002-01-01

    SiC is a wide-gap material with excellent electrical and physical properties that may make it an important material for some future electronic devices. The most important possible applications of SiC are in hostile environments, such as in car\\/jet engines, within nuclear reactors, or in outer space. Another area where the material properties, most notably radiation hardness, would be valuable is

  17. Characterisation of vertical gradient freeze semi-insulating InP for use as a nuclear radiation detector

    Microsoft Academic Search

    H. El-Abbassi; S. Rath; P. J. Sellin

    2001-01-01

    The performance of a nuclear radiation detector fabricated from Vertical Gradient Freeze (VGF) semi-insulating Fe-doped InP was investigated. Pulse height spectra were acquired when the detector was irradiated with alpha particles from 241Am, as a function of temperature and detector bias voltage. The spectroscopic performance of the detector was limited at room temperature due to the presence of a high

  18. Radiation hard blocked tunneling band {GaAs}/{AlGaAs} superlattice long wavelength infrared detectors

    NASA Astrophysics Data System (ADS)

    Wu, C. S.; Wen, C. P.; Reiner, P.; Tu, C. W.; Hou, H. Q.

    1996-09-01

    We have developed a novel multiple quantum well (MQW) long wavelength infrared (LWIR) detector which can operate in a photovoltaic detection mode with an intrinsic event discrimination (IED) capability. The detector was constructed using the {GaAs}/{AlGaAs} MQW technology to form a blocked tunneling band superlattice structure with a 10.2 micron wavelength and 2.2 micron bandwidth. The detector exhibited Schottky junction and photovoltaic detection characteristics with extremely low dark current and low noise as a result of a built-in tunneling current blocking layer structure. In order to enhance quantum efficiency, a built-in electric field was created by grading the doping concentration of each quantum well in the MQW region. The peak responsivity of the detector was 0.4 amps/W with a measured detectivity of 6.0 × 10 11 Jones. The external quantum efficiency was measured to be 4.4%. The detector demonstrated an excellent intrinsic event discrimination capability due to the presence of a p-type GaAs hole collector layer, which was grown on top of the n-type electron emitter region of the MQW detector. The best results show that an infrared signal which is as much as 100 times smaller than coincident nuclear radiation induced current can be distinguished and extracted from the noise signal. With this hole collector structure, our detector also demonstrated two-color detection.

  19. Development of an alpha/beta/gamma detector for radiation monitoring

    SciTech Connect

    Yamamoto, Seiichi [Kobe City College of Technology, 8-3, Gakuen-Higashi-machi, Nishi-ku, Kobe, 651-2194 (Japan); Hatazawa, Jun [Osaka University of Graduate School of Medicine, 2-2, Yamadaoka, Suita-shi, Osaka, 565-0871 (Japan)

    2011-11-15

    For radiation monitoring at the site of nuclear power plant accidents such as Fukushima Daiichi, radiation detectors not only for gamma photons but also for alpha and beta particles are needed because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. We developed a radiation detector that can simultaneously monitor alpha and beta particles and gamma photons for radiation monitoring. The detector consists of three-layered scintillators optically coupled to each other and coupled to a photomultiplier tube. The first layer, which is made of a thin plastic scintillator (decay time: 2.4 ns), detects alpha particles. The second layer, which is made of a thin Gd{sub 2}SiO{sub 5} (GSO) scintillator with 1.5 mol.% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol.% Ce (decay time: 70 ns) detects gamma photons. By using pulse shape discrimination, the count rates of these layers can be separated. With individual irradiation of alpha and beta particles and gamma photons, the count rate of the first layer represented the alpha particles, the second layer represented the beta particles, and the third layer represented the gamma photons. Even with simultaneous irradiation of the alpha and beta particles and the gamma photons, these three types of radiation can be individually monitored using correction for the gamma detection efficiency of the second and third layers. Our developed alpha, beta, and gamma detector is simple and will be useful for radiation monitoring, especially at nuclear power plant accident sites or other applications where the simultaneous measurements of alpha and beta particles and gamma photons are required.

  20. Development of an alpha/beta/gamma detector for radiation monitoring.

    PubMed

    Yamamoto, Seiichi; Hatazawa, Jun

    2011-11-01

    For radiation monitoring at the site of nuclear power plant accidents such as Fukushima Daiichi, radiation detectors not only for gamma photons but also for alpha and beta particles are needed because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. We developed a radiation detector that can simultaneously monitor alpha and beta particles and gamma photons for radiation monitoring. The detector consists of three-layered scintillators optically coupled to each other and coupled to a photomultiplier tube. The first layer, which is made of a thin plastic scintillator (decay time: 2.4 ns), detects alpha particles. The second layer, which is made of a thin Gd(2)SiO(5) (GSO) scintillator with 1.5 mol.% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol.% Ce (decay time: 70 ns) detects gamma photons. By using pulse shape discrimination, the count rates of these layers can be separated. With individual irradiation of alpha and beta particles and gamma photons, the count rate of the first layer represented the alpha particles, the second layer represented the beta particles, and the third layer represented the gamma photons. Even with simultaneous irradiation of the alpha and beta particles and the gamma photons, these three types of radiation can be individually monitored using correction for the gamma detection efficiency of the second and third layers. Our developed alpha, beta, and gamma detector is simple and will be useful for radiation monitoring, especially at nuclear power plant accident sites or other applications where the simultaneous measurements of alpha and beta particles and gamma photons are required. PMID:22128972

  1. Modeling the instantaneous dose rate dependence of radiation diode detectors.

    PubMed

    Shi, Jie; Simon, William E; Zhu, Timothy C

    2003-09-01

    The sensitivity S of Si diodes generally increases with an increase in the instantaneous dose rate r of the radiation beam from clinical linear accelerators. A theoretical model is established to understand the physical origin of this dependence. During a radiation exposure, a portion of the excess minority carriers (electrons or holes) generated in the diode is captured by the R-G (recombination-generation) centers and is recombined with the majority carriers. The captured portion depends on the excess minority-carrier concentration delta p (proportional to r), the R-G center concentration N(t), and the minority-carrier capture cross-sections (sigma(n) for electrons and sigma(p) for holes) by the R-G center. When r increases, the R-G center concentration may not be sufficient to keep the recombination portion constant, which leads to an increase in diode sensitivity because a larger fraction of the charge will be collected. Larger majority-carrier concentration increases the recombination probability of the excess minority carriers and thus decreases the r dependence. The ratio of minority-carrier capture cross-sections, sigma(p)/sigma(n), influences the magnitude of the r dependence and also differentiates the r dependence between n-type and p-type diodes. A number of different circumstances can occur in diodes. When sigma(p) > sigma(n), such as for the dominant R-G center generated by electron radiation, the sensitivity is more dependent on r in an n-type diode than in a p-type diode if all the other device parameters are the same. When sigma(p) < sigma(n), the sensitivity is then more dependent on r in a p-type diode than in an n-type diode. The condition of sigma(p) < sigma(n) can occur when R-G centers with this property are generated by the foundry die process. A diode could have very small r dependence due to large R-G center concentration, generated by heavy platinum doping or radiation accumulated dose. Experimental data are compared with theory. PMID:14528973

  2. Study of the current voltage characteristics of a SiC radiation detector irradiated by Co60 gamma-rays

    Microsoft Academic Search

    S. M. Kang; J. H. Ha; S. H. Park; H. S. Kim; S. D. Chun; Y. K. Kim

    2007-01-01

    The SiC semiconductor has recently emerged as an attractive material for an ionization radiation detection. A wide bandgap (3.03 eV) and high radiation damage resistance allow for the fabrication of detectors capable of operating at a high-temperature and in high radiation fields. The major aim of our study is to develop a robust detector which will be applied to harsh

  3. Effects of Te inclusions on the performance of CdZnTe radiation detectors

    SciTech Connect

    Bolotnikov,A.E.; Abdul-Jabber, N. M.; Babalola, O. S.; Camarda, G. S.; Cui, Y.; Hossain, A. M.; Jackson, E. M.; Jackson, H. C.; James, J. A.; Kohman, K. T.; Luryi, A. L.; James, R. B.

    2008-10-19

    Te inclusions existing at high concentrations in CdZnTe (CZT) material can degrade the performance of CZT detectors. These microscopic defects trap the free electrons generated by incident radiation, so entailing significant fluctuations in the total collected charge and thereby strongly affecting the energy resolution of thick (long-drift) detectors. Such effects were demonstrated in thin planar detectors, and, in many cases, they proved to be the dominant cause of the low performance of thick detectors, wherein the fluctuations in the charge losses accumulate along the charge's drift path. We continued studying this effect using different tools and techniques. We employed a dedicated beamline recently established at BNL's National Synchrotron Light Source for characterizing semiconductor radiation detectors, along with an IR transmission microscope system, the combination of which allowed us to correlate the concentration of defects with the devices performances. We present here our new results from testing over 50 CZT samples grown by different techniques. Our goals are to establish tolerable limits on the size and concentrations of these detrimental Te inclusions in CZT material, and to provide feedback to crystal growers to reduce their numbers in the material.

  4. Recent advancements in the development of radiation hard semiconductor detectors for S-LHC

    NASA Astrophysics Data System (ADS)

    Fretwurst, E.; Adey, J.; Al-Ajili, A.; Alfieri, G.; Allport, P. P.; Artuso, M.; Assouak, S.; Avset, B. S.; Barabash, L.; Barcz, A.; Bates, R.; Biagi, S. F.; Bilei, G. M.; Bisello, D.; Blue, A.; Blumenau, A.; Boisvert, V.; Bolla, G.; Bondarenko, G.; Borchi, E.; Borrello, L.; Bortoletto, D.; Boscardin, M.; Bosisio, L.; Bowcock, T. J. V.; Brodbeck, T. J.; Broz, J.; Bruzzi, M.; Brzozowski, A.; Buda, M.; Buhmann, P.; Buttar, C.; Campabadal, F.; Campbell, D.; Candelori, A.; Casse, G.; Cavallini, A.; Charron, S.; Chilingarov, A.; Chren, D.; Cindro, V.; Collins, P.; Coluccia, R.; Contarato, D.; Coutinho, J.; Creanza, D.; Cunningham, L.; Dalla Betta, G.-F.; Dawson, I.; de Boer, W.; De Palma, M.; Demina, R.; Dervan, P.; Dittongo, S.; Dolezal, Z.; Dolgolenko, A.; Eberlein, T.; Eremin, V.; Fall, C.; Fasolo, F.; Ferbel, T.; Fizzotti, F.; Fleta, C.; Focardi, E.; Forton, E.; Garcia, C.; Garcia-Navarro, J. E.; Gaubas, E.; Genest, M.-H.; Gill, K. A.; Giolo, K.; Glaser, M.; Goessling, C.; Golovine, V.; González Sevilla, S.; Gorelov, I.; Goss, J.; Gouldwell Bates, A.; Grégoire, G.; Gregori, P.; Grigoriev, E.; Grillo, A. A.; Groza, A.; Guskov, J.; Haddad, L.; Härkönen, J.; Hauler, F.; Hoeferkamp, M.; Hönniger, F.; Horazdovsky, T.; Horisberger, R.; Horn, M.; Houdayer, A.; Hourahine, B.; Hughes, G.; Ilyashenko, I.; Irmscher, K.; Ivanov, A.; Jarasiunas, K.; Johansen, K. M. H.; Jones, B. K.; Jones, R.; Joram, C.; Jungermann, L.; Kalinina, E.; Kaminski, P.; Karpenko, A.; Karpov, A.; Kazlauskiene, V.; Kazukauskas, V.; Khivrich, V.; Khomenkov, V.; Kierstead, J.; Klaiber-Lodewigs, J.; Klingenberg, R.; Kodys, P.; Kohout, Z.; Korjenevski, S.; Koski, M.; Kozlowski, R.; Kozodaev, M.; Kramberger, G.; Krasel, O.; Kuznetsov, A.; Kwan, S.; Lagomarsino, S.; Lassila-Perini, K.; Lastovetsky, V.; Latino, G.; Lazanu, I.; Lazanu, S.; Lebedev, A.; Lebel, C.; Leinonen, K.; Leroy, C.; Li, Z.; Lindström, G.; Linhart, V.; Litovchenko, P.; Litovchenko, A.; Lo Giudice, A.; Lozano, M.; Luczynski, Z.; Luukka, P.; Macchiolo, A.; Makarenko, L. F.; Mandi?, I.; Manfredotti, C.; Manna, N.; Marti i Garcia, S.; Marunko, S.; Mathieson, K.; Melone, J.; Menichelli, D.; Messineo, A.; Metcalfe, J.; Miglio, S.; Mikuž, M.; Miyamoto, J.; Moll, M.; Monakhov, E.; Moscatelli, F.; Naoumov, D.; Nossarzewska-Orlowska, E.; Nysten, J.; Olivero, P.; Oshea, V.; Palviainen, T.; Paolini, C.; Parkes, C.; Passeri, D.; Pein, U.; Pellegrini, G.; Perera, L.; Petasecca, M.; Piemonte, C.; Pignatel, G. U.; Pinho, N.; Pintilie, I.; Pintilie, L.; Polivtsev, L.; Polozov, P.; Popa, A.; Popule, J.; Pospisil, S.; Pozza, A.; Radicci, V.; Rafí, J. M.; Rando, R.; Roeder, R.; Rohe, T.; Ronchin, S.; Rott, C.; Roy, A.; Ruzin, A.; Sadrozinski, H. F. W.; Sakalauskas, S.; Scaringella, M.; Schiavulli, L.; Schnetzer, S.; Schumm, B.; Sciortino, S.; Scorzoni, A.; Segneri, G.; Seidel, S.; Seiden, A.; Sellberg, G.; Sellin, P.; Sentenac, D.; Shipsey, I.; Sicho, P.; Sloan, T.; Solar, M.; Son, S.; Sopko, B.; Sopko, V.; Spencer, N.; Stahl, J.; Stolze, D.; Stone, R.; Storasta, J.; Strokan, N.; Sudzius, M.; Surma, B.; Suvorov, A.; Svensson, B. G.; Tipton, P.; Tomasek, M.; Tsvetkov, A.; Tuominen, E.; Tuovinen, E.; Tuuva, T.; Tylchin, M.; Uebersee, H.; Uher, J.; Ullán, M.; Vaitkus, J. V.; Velthuis, J.; Verbitskaya, E.; Vrba, V.; Wagner, G.; Wilhelm, I.; Worm, S.; Wright, V.; Wunstorf, R.; Yiuri, Y.; Zabierowski, P.; Zaluzhny, A.; Zavrtanik, M.; Zen, M.; Zhukov, V.; Zorzi, N.

    2005-10-01

    The proposed luminosity upgrade of the Large Hadron Collider (S-LHC) at CERN will demand the innermost layers of the vertex detectors to sustain fluences of about 10 16 hadrons/cm 2. Due to the high multiplicity of tracks, the required spatial resolution and the extremely harsh radiation field new detector concepts and semiconductor materials have to be explored for a possible solution of this challenge. The CERN RD50 collaboration "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" has started in 2002 an R&D program for the development of detector technologies that will fulfill the requirements of the S-LHC. Different strategies are followed by RD50 to improve the radiation tolerance. These include the development of defect engineered silicon like Czochralski, epitaxial and oxygen-enriched silicon and of other semiconductor materials like SiC and GaN as well as extensive studies of the microscopic defects responsible for the degradation of irradiated sensors. Further, with 3D, Semi-3D and thin devices new detector concepts have been evaluated. These and other recent advancements of the RD50 collaboration are presented and discussed.

  5. Radiation Effects of n-type, Low Resistivity, Spiral Silicon Drift Detector Hybrid Systems

    SciTech Connect

    Chen W.; De Geronimo G.; Carini, G.A.; Gaskin, J.A.; Keister, J.W.; Li, S.; Li, Z.; Ramsey, B.D.; Siddons, D.P.; Smith, G.C.; Verbitskaya, E.

    2011-11-15

    We have developed a new thin-window, n-type, low-resistivity, spiral silicon drift detector (SDD) array - to be used as an extraterrestrial X-ray spectrometer (in varying environments) for NASA. To achieve low-energy response, a thin SDD entrance window was produced using a previously developed method. These thin-window devices were also produced on lower resistivity, thinner, n-type, silicon material, effectively ensuring their radiation hardness in anticipation of operation in potentially harsh radiation environments (such as found around the Jupiter system). Using the Indiana University Cyclotron Facility beam line RERS1, we irradiated a set of suitable diodes up to 5 Mrad and the latest iteration of our ASICs up to 12 Mrad. Then we irradiated two hybrid detectors consisting of newly, such-produced in-house (BNL) SDD chips bonded with ASICs with doses of 0.25 Mrad and 1 Mrad. Also we irradiated another hybrid detector consisting of previously produced (by KETEK) on n-type, high-resistivity SDD chip bonded with BNL's ASICs with a dose of 1 Mrad. The measurement results of radiated diodes (up to 5 Mrad), ASICs (up to 12 Mrad) and hybrid detectors (up to 1 Mrad) are presented here.

  6. Advanced radiation detector development: Advanced semiconductor detector development: Development of a room-temperature, gamma ray detector using gallium arsenide to develop an electrode detector. Annual progress report, September 30, 1994--September 29, 1995

    SciTech Connect

    Knoll, G.F.

    1995-11-01

    The advanced detector development project at the University of Michigan has completed the first full year of its current funding. The general goals are the development of radiation detectors and spectrometers that are capable of portable room temperature operation. Over the past 12 months, the authors have worked primarily in the development of semiconductor spectrometers with ``single carrier`` response that offer the promise of room temperature operation and good energy resolution in gamma ray spectroscopy. They have also begun a small scale effort at investigating the properties of a small non-spectroscopic detector system with directional characteristics that will allow identification of the approximate direction in which gamma rays are incident. These activities have made use of the extensive clean room facilities at the University of Michigan for semiconductor device fabrication, and also the radiation measurement capabilities provided in the laboratory in the Phoenix Building on the North Campus.

  7. Prototype Radiation Detector Positioning System For The Automated Nondestructive Assay Of Uf6 Cylinders

    SciTech Connect

    Hatchell, Brian K.; Valdez, Patrick LJ; Orton, Christopher R.; Mace, Emily K.

    2011-08-07

    International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility’s entire cylinder inventory. These measurements are time-consuming, expensive, and assay only a small fraction of the total cylinder volume. An automated nondestructive assay system capable of providing enrichment measurements over the full volume of the cylinder could improve upon current verification practices in terms of efficiency and assay accuracy. This paper describes an approach denoted the Integrated Cylinder Verification Station (ICVS) that supports 100% cylinder verification, provides volume-averaged cylinder enrichment assay, and reduces inspector manpower needs. To allow field measurements to be collected to validate data collection algorithms, a prototype radiation detector positioning system was constructed. The system was designed to accurately position an array of radiation detectors along the length of a cylinder to measure UF6 enrichment. A number of alternative radiation shields for the detectors were included with the system. A collimated gamma-ray spectrometer module that allows translation of the detectors in the surrounding shielding to adjust the field of view, and a collimating plug in the end to further reduce the low-energy field of view, were also developed. Proof-of-principle measurements of neutron and high-energy gamma-ray signatures, using moderated neutron detectors and large-volume spectrometers in a fixed-geometry, portal-like configuration, supported an early assessment of the viability of the concept. The system has been used successfully on two testing campaigns at an AREVA fuel fabrication plant to scan over 30 product cylinders. This paper will describe the overall design of the detector positioning system and provide an overview of the Integrated Cylinder Verification Station (ICVS) approach.

  8. The simulation of the LANFOS-H food radiation contamination detector using Geant4 package

    NASA Astrophysics Data System (ADS)

    Piotrowski, Lech Wiktor; Casolino, Marco; Ebisuzaki, Toshikazu; Higashide, Kazuhiro

    2015-02-01

    Recent incident in the Fukushima power plant caused a growing concern about the radiation contamination and resulted in lowering the Japanese limits for the permitted amount of 137Cs in food to 100 Bq/kg. To increase safety and ease the concern we are developing LANFOS (Large Food Non-destructive Area Sampler)-a compact, easy to use detector for assessment of radiation in food. Described in this paper LANFOS-H has a 4 ? coverage to assess the amount of 137Cs present, separating it from the possible 40K food contamination. Therefore, food samples do not have to be pre-processed prior to a test and can be consumed after measurements. It is designed for use by non-professionals in homes and small institutions such as schools, showing safety of the samples, but can be also utilized by specialists providing radiation spectrum. Proper assessment of radiation in food in the apparatus requires estimation of the ? conversion factor of the detectors-how many ? photons will produce a signal. In this paper we show results of the Monte Carlo estimation of this factor for various approximated shapes of fish, vegetables and amounts of rice, performed with Geant4 package. We find that the conversion factor combined from all the detectors is similar for all food types and is around 37%, varying maximally by 5% with sample length, much less than for individual detectors. The different inclinations and positions of samples in the detector introduce uncertainty of 1.4%. This small uncertainty validates the concept of a 4 ? non-destructive apparatus.

  9. Radiation damage effects on detectors and eletronic devices in harsh radiation environment

    E-print Network

    Fiore, S

    2015-01-01

    Radiation damage effects represent one of the limits for technologies to be used in harsh radiation environments as space, radiotherapy treatment, high-energy phisics colliders. Different technologies have known tolerances to different radiation fields and should be taken into account to avoid unexpected failures which may lead to unrecoverable damages to scientific missions or patient health.

  10. Passive Radiator For Cooling IR Detectors In Geostationary Orbit

    NASA Astrophysics Data System (ADS)

    Grigg, R.; Havey, K.; Meyers, J.

    1985-12-01

    This paper presents an approach to the design, analysis, fabrication, and a test of a development model of 100 K passive space radiator for a geostationary meteorological satellite. Significant design considerations include the importance of heat-leak control at low temperatures and the importance of a well devised plan for elimination and control of moisture and contaminants. Fabrication issues include the ability of the design to be compatible with spacecraft assembly as well as to accommodate disassembly for repair or access to the focal plane. The results of a test of the development model are presented. The data correlation process is discussed and the need for a good means of determination of surface properties at cold temperatures is identified. A summary of recommended design and fabrication features is presented.

  11. A leakage current-based measurement of the radiation damage in the ATLAS Pixel Detector

    NASA Astrophysics Data System (ADS)

    Gorelov, I. V.

    2015-04-01

    A measurement has been made of the radiation damage incurred by the ATLAS Pixel Detector barrel silicon modules from the beginning of operations through the end of 2012. This translates to hadronic fluence received over the full period of operation at energies up to and including (8 TeV). The measurement is based on a per-module measurement of the silicon sensor leakage current. The results are presented as a function of integrated luminosity and compared to predictions by the Hamburg Model. This information can be used to predict limits on the lifetime of the Pixel Detector due to current, for various operating scenarios.

  12. A Leakage Current-based Measurement of the Radiation Damage in the ATLAS Pixel Detector

    E-print Network

    Igor V. Gorelov; for the ATLAS Collaboration

    2015-02-12

    A measurement has been made of the radiation damage incurred by the ATLAS Pixel Detector barrel silicon modules from the beginning of operations through the end of 2012. This translates to hadronic fluence received over the full period of operation at energies up to and including 8 TeV. The measurement is based on a per-module measurement of the silicon sensor leakage current. The results are presented as a function of integrated luminosity and compared to predictions by the Hamburg Model. This information can be used to predict limits on the lifetime of the Pixel Detector due to current, for various operating scenarios.

  13. Gamma spectroscopic measurements using the PID350 pixelated CdTe radiation detector

    E-print Network

    Karafasoulis, K; Seferlis, S; Papadakis, I; Loukas, D; Lambropoulos, C; Potiriadis, C

    2010-01-01

    Spectroscopic measurements are presented using the PID350 pixelated gamma radiation detectors. A high-speed data acquisition system has been developed in order to reduce the data loss during the data reading in case of a high flux of photons. A data analysis framework has been developed in order to improve the resolution of the acquired energy spectra, using specific calibration parameters for each PID350's pixel. Three PID350 detectors have been used to construct a stacked prototype system and spectroscopic measurements have been performed in order to test the ability of the prototype to localize radioactive sources.

  14. Gamma spectroscopic measurements using the PID350 pixelated CdTe radiation detector

    E-print Network

    K. Karafasoulis; K. Zachariadou; S. Seferlis; I. Papadakis; D. Loukas; C. Lambropoulos; C. Potiriadis

    2010-11-15

    Spectroscopic measurements are presented using the PID350 pixelated gamma radiation detectors. A high-speed data acquisition system has been developed in order to reduce the data loss during the data reading in case of a high flux of photons. A data analysis framework has been developed in order to improve the resolution of the acquired energy spectra, using specific calibration parameters for each PID350's pixel. Three PID350 detectors have been used to construct a stacked prototype system and spectroscopic measurements have been performed in order to test the ability of the prototype to localize radioactive sources.

  15. Earth radiation budget measurement from a spinning satellite: Conceptual design of detectors

    NASA Technical Reports Server (NTRS)

    Sromovsky, L. A.; Revercomb, H. E.; Suomi, V. E.

    1975-01-01

    The conceptual design, sensor characteristics, sensor performance and accuracy, and spacecraft and orbital requirements for a spinning wide-field-of-view earth energy budget detector were investigated. The scientific requirements for measurement of the earth's radiative energy budget are presented. Other topics discussed include the observing system concept, solar constant radiometer design, plane flux wide FOV sensor design, fast active cavity theory, fast active cavity design and error analysis, thermopile detectors as an alternative, pre-flight and in-flight calibration plane, system error summary, and interface requirements.

  16. Defects and radiation damage in semi-insulating GaAs radiation detectors

    Microsoft Academic Search

    J. Vaitkus; V. Kazukauskas; R. Didziulis; J. Storasta; R. Bates; V O'Shea; C. Raine; K. M Smith

    1998-01-01

    Thermally stimulated current (TSC) and depolarisation (TSD), measurements and detailed analysis of current - voltage (I-V) characteristics have been made on semi-insulating GaAs (SI-GaAs) Schottky diode particle detectors, fabricated on substrates from several suppliers, before and after irradiation with high-energy protons and pions. The analysis of I-V characteristics allows the determination of the barrier height and bulk resistance in detectors.

  17. Microinhomogeneity effects and radiation damage in semi-insulating GaAs radiation detectors

    Microsoft Academic Search

    R. Bates; R. Didziulis; V. Kazukauskas; V. O'Shea; C. Raine; V. Rinkevioius; K. M. Smith; J. Storasta; J. Vaitkus

    1998-01-01

    Thermally-stimulated current (TSC) measurements and a detailed analysis of current-voltage (I-V) characteristics have been made on semi-insulating GaAs (SI-GaAs) Schottky diode particle detectors, fabricated on substrates from several suppliers, before and after irradiation with 24 GeV protons and 300 MeV pions. The analysis of I-V characteristics allows the determination of the barrier height and bulk resistance in detectors. Changes observed

  18. Electrodrift purification of materials for room temperature radiation detectors

    DOEpatents

    James, R.B.; Van Scyoc, J.M. III; Schlesinger, T.E.

    1997-06-24

    A method of purifying nonmetallic, crystalline semiconducting materials useful for room temperature radiation detecting devices by applying an electric field across the material is disclosed. The present invention discloses a simple technology for producing purified ionic semiconducting materials, in particular PbI{sub 2} and preferably HgI{sub 2}, which produces high yields of purified product, requires minimal handling of the material thereby reducing the possibility of introducing or reintroducing impurities into the material, is easy to control, is highly selective for impurities, retains the stoichiometry of the material and employs neither high temperatures nor hazardous materials such as solvents or liquid metals. An electric field is applied to a bulk sample of the material causing impurities present in the sample to drift in a preferred direction. After all of the impurities have been transported to the ends of the sample the current flowing through the sample, a measure of the rate of transport of mobile impurities, falls to a low, steady state value, at which time the end sections of the sample where the impurities have concentrated are removed leaving a bulk sample of higher purity material. Because the method disclosed here only acts on the electrically active impurities, the stoichiometry of the host material remains substantially unaffected. 4 figs.

  19. Polymerconcrete for Radiation Background Shielding of Detectors at Hadron Colliders

    NASA Astrophysics Data System (ADS)

    Astapov, A. A.; Zaitsev, L. N.; Zaitsev, S. L.

    1997-05-01

    New shielding material - polymerconcrete with density 1.2dots 3.6 g\\cdotcm-3 and H, Li or B contents (4dots6.6)\\cdot10^22 H\\cdotcm-3, 1.3\\cdot10^22 Li\\cdotcm-3 or 3.3\\cdot10^21 B\\cdotcm-3, respectively, is developed. Granular polythene, lead powder, lithium salts or boron carbide are cemented by the special cement, dissolved in the liquid polymer. Material samples have lower limits of the resistance to compression 42 MPa, the resistance to rupture 6 MPa and the dynamic coefficient of elasticity 10^3 MPa. Radiation resistance, tested at the reactor IBR-2 and accelerators at JINR, IHEP and ITEP is 10^3 Mrad at 10 krad\\cdots-1 and 1 Mrad at 10 rad\\cdots-1. It is enough for a future colliders. Our experimental results demonstrate, that the induced radioactivity levels for the polymerconcrete are lower than ones for a ordinary concretes. It is shown that density 3.2dots 3.6 g\\cdotcm-3 of a steel-concrete composition is optimum to get the minimum shielding thickness and cost. Polymerconcrete can be used as bricks or for the filling in any forms. It is suggesting to use this material instead CH2 and Pb for shielding of the setups D0 and CDF at the Tevatron and CMS, ATLAS, ALICE at the LHC.

  20. Electrodrift purification of materials for room temperature radiation detectors

    DOEpatents

    James, Ralph B. (5420 Lenore Ave., Livermore, Alameda County, CA 94550); Van Scyoc, III, John M. (P.O. Box 93, 65 Main St., Apt. 1, Plainfield, Cumberland County, PA 17081); Schlesinger, Tuviah E. (8 Carleton Dr., Mt. Lebanon, Allegheny County, PA 15243)

    1997-06-24

    A method of purifying nonmetallic, crystalline semiconducting materials useful for room temperature radiation detecting devices by applying an electric field across the material. The present invention discloses a simple technology for producing purified ionic semiconducting materials, in particular PbI.sub.2 and preferably HgI.sub.2, which produces high yields of purified product, requires minimal handling of the material thereby reducing the possibility of introducing or reintroducing impurities into the material, is easy to control, is highly selective for impurities, retains the stoichiometry of the material and employs neither high temperatures nor hazardous materials such as solvents or liquid metals. An electric field is applied to a bulk sample of the material causing impurities present in the sample to drift in a preferred direction. After all of the impurities have been transported to the ends of the sample the current flowing through the sample, a measure of the rate of transport of mobile impurities, falls to a low, steady state value, at which time the end sections of the sample where the impurities have concentrated are removed leaving a bulk sample of higher purity material. Because the method disclosed here only acts on the electrically active impurities, the stoichiometry of the host material remains substantially unaffected.

  1. A high rate transition radiation detector for particle identification in a hadron beam

    SciTech Connect

    Errede, D.; Sheaff, M.; Fenker, H.; Mantsch, P.

    1989-08-01

    A Transition Radiation Detector (TRD) was built for the purpose of tagging beam particles in a high rate (/approximately/2 MHz) 250 GeV/c hadron beam during data taking for Experiment 769 at Fermilab. The availability of a good ''tool kit'', including a Monte Carlo program which could reliably predict the detector performance, made it possible to design and build the TRD in approximately one year. Pion or proton samples, each with a small contamination due to the other, could be selected with high efficiency by making cuts on the number of planes of the TRD registering hits for each incident beam particle. The detector is expected to work well to separate kaons from pions in the 500 GeV/c negative beam for E791. 15 refs., 8 figs., 1 tab.

  2. Current-driven detection of terahertz radiation using a dual-grating-gate plasmonic detector

    SciTech Connect

    Boubanga-Tombet, S., E-mail: stephanealbon@hotmail.com; Tanimoto, Y.; Satou, A.; Suemitsu, T.; Otsuji, T. [Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai 980-8577 (Japan); Wang, Y.; Minamide, H.; Ito, H. [RIKEN Sendai, 519-1399 Aramaki Aoba, Aoba-ku, Sendai 980-0845 (Japan); Fateev, D. V.; Popov, V. V. [Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), 410019 Saratov (Russian Federation); Saratov State University, 410012 Saratov (Russian Federation)

    2014-06-30

    We report on the detection of terahertz radiation by an on-chip planar asymmetric plasmonic structure in the frequency region above one terahertz. The detector is based on a field-effect transistor that has a dual grating gate structure with an asymmetric unit cell, which provides a geometrical asymmetry within the structure. Biasing the detector with a dc source-to-drain current in the linear region of the current-voltage characteristic introduces an additional asymmetry (electrical asymmetry) that enhances the detector responsivity by more than one order of magnitude (by a factor of 20) as compared with the unbiased case due to the cooperative effect of the geometrical and electrical asymmetries. In addition to the responsivity enhancement, we report a relatively low noise equivalent power and a peculiar non-monotonic dependence of the responsivity on the frequency, which results from the multi-plasmonic-cavity structure of the device.

  3. Single-detector searches for a stochastic background of gravitational radiation

    E-print Network

    Massimo Tinto; J. W. Armstrong

    2012-05-21

    We propose a data processing technique that allows searches for a stochastic background of gravitational radiation with data from a single detector. Our technique exploits the difference between the coherence time of the gravitational wave (GW) signal and that of the instrumental noise affecting the measurements. By estimating the auto-correlation function of the data at an off-set time that is longer than the coherence time of the noise {\\underbar {but}} shorter than the coherence time of the GW signal, we can effectively enhance the power signal-to-noise ratio (SNR) by the square-root of the integration time. The resulting SNR is comparable in magnitude to that achievable by cross-correlating the data from two co-located and co-aligned detectors whose noises are uncorrelated. Our method is general and it can be applied to data from ground- and space-based detectors, as well as from pulsar timing experiments.

  4. Measurement of the energy spectrum of underground muons at Gran Sasso with a transition radiation detector

    E-print Network

    The MACRO Collaboration; M. Ambrosio et al

    1998-07-09

    We have measured directly the residual energy of cosmic ray muons crossing the MACRO detector at the Gran Sasso Laboratory. For this measurement we have used a transition radiation detector consisting of three identical modules, each of about 12 m^2 area, operating in the energy region from 100 GeV to 1 TeV. The results presented here were obtained with the first module collecting data for more than two years. The average single muon energy is found to be 320 +/- 4 (stat.) +/- 11 (syst.) GeV in the rock depth range 3000-6500 hg/cm^2. The results are in agreement with calculations of the energy loss of muons in the rock above the detector.

  5. VHMPID RICH prototype using pressurized C4F8O radiator gas and VUV photon detector

    NASA Astrophysics Data System (ADS)

    Acconcia, T. V.; Agócs, A. G.; Barile, F.; Barnaföldi, G. G.; Bellwied, R.; Bencédi, G.; Bencze, G.; Berényi, D.; Boldizsár, L.; Chattopadhyay, S.; Chinellato, D. D.; Cindolo, F.; Cossyleon, K.; Das, D.; Das, K.; Das-Bose, L.; Dash, A. K.; D`Ambrosio, S.; De Cataldo, G.; De Pasquale, S.; Di Bari, D.; Di Mauro, A.; Futó, E.; Garcia-Solis, E.; Hamar, G.; Harton, A.; Iannone, G.; Jimenez, R. T.; Kim, D. W.; Kim, J. S.; Knospe, A.; Kovács, L.; Lévai, P.; Markert, C.; Martinengo, P.; Molnár, L.; Nappi, E.; Oláh, L.; Pai?, G.; Pastore, C.; Patimo, G.; Patino, M. E.; Peskov, V.; Pinsky, L.; Piuz, F.; Pochybová, S.; Sgura, I.; Sinha, T.; Song, J.; Takahashi, J.; Timmins, A.; Van Beelen, J. B.; Varga, D.; Volpe, G.; Weber, M.; Xaplanteris, L.; Yi, J.; Yoo, I.-K.

    2014-12-01

    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.

  6. Modeling the response of thermoluminescence detectors exposed to low- and high-LET radiation fields.

    PubMed

    Olko, Pawel; Bilski, Pawel; Budzanowski, Maciej; Waligórski, Michael Patrick Russell; Reitz, Guenther

    2002-12-01

    Lithium fluoride thermoluminescence (TL) detectors, with different Li composition (Li-6 and Li-7) and various activators (LiF:Mg,Ti, LiF:Mg,Cu,P), are widely used for dosimetry in space. The primary radiation field in space is composed of fast electrons, protons and heavy charged particles (HCP). By its interaction with the structures of the spacecraft, this field may be modified inside the crew cabin. Therefore, calibration of TL detectors against a dose of gamma-rays is not sufficient for relating the TL readout to absorbed dose or to quantities relevant in radiation protection, without suitable correction. We introduce and calculate the detection efficiency, eta, relative to gamma-ray dose, of lithium fluoride detectors after proton and heavy charged particle (HCP) irradiation. We calculate eta for MCP-N (LiF:Mg,Cu,P) and for MTS-N (LiF:Mg,Ti) using microdosimetric models. The microdosimetric distributions used in these models (for HCP of charges between Z=1 to Z=8 and in the energy range between 0.3 MeV/amu and 20 MeV/amu) are calculated using an analytical model, based on the results of Monte Carlo simulated charged particle tracks using the MOCA-14 code. The ratio etaMCP-N/etaMTS-N for protons of stopping power (in water) below 10 keV/microm lies in the range between 0.65 and 1.0 and for HCP with Z>1--between 0.3 and 0.6. The stopping power of the particle is found not to be a unique parameter to scale the response of TL detectors. The combination of response of LiF:Mg,Cu,P and LiF:Mg,Cu,P detectors can be more suitable for a dose correction in space radiation fields. PMID:12793731

  7. Comparison of Direct Normal Irradiance Derived from Silicon and Thermopile Global Hemispherical Radiation Detectors: Preprint

    SciTech Connect

    Myers, D. R.

    2010-01-01

    Concentrating solar applications utilize direct normal irradiance (DNI) radiation, a measurement rarely available. The solar concentrator industry has begun to deploy numerous measurement stations to prospect for suitable system deployment sites. Rotating shadowband radiometers (RSR) using silicon photodiodes as detectors are typically deployed. This paper compares direct beam estimates from RSR to a total hemispherical measuring radiometer (SPN1) multiple fast thermopiles. These detectors simultaneously measure total and diffuse radiation from which DNI can be computed. Both the SPN1 and RSR-derived DNI are compared to DNI measured with thermopile pyrheliometers. Our comparison shows that the SPN1 radiometer DNI estimated uncertainty is somewhat greater than, and on the same order as, the RSR DNI estimates for DNI magnitudes useful to concentrator technologies.

  8. Comparison of direct normal irradiance derived from silicon and thermopile global hemispherical radiation detectors

    NASA Astrophysics Data System (ADS)

    Myers, Daryl R.

    2010-08-01

    Concentrating solar applications utilize direct normal irradiance (DNI) radiation, a measurement rarely available. The solar concentrator industry has begun to deploy numerous measurement stations to prospect for suitable system deployment sites. Rotating shadowband radiometers (RSR) using silicon photodiodes as detectors are typically deployed. This paper compares direct beam estimates from RSR to a total hemispherical measuring radiometer (SPN1) multiple fast thermopiles. These detectors simultaneously measure total and diffuse radiation from which DNI can be computed. Both the SPN1 and RSR-derived DNI are compared to DNI measured with thermopile pyrheliometers. Our comparison shows that the SPN1 radiometer DNI estimated uncertainty is somewhat greater than, and on the same order as, the RSR DNI estimates for DNI magnitudes useful to concentrator technologies.

  9. A 2D DNA lattice as an ultrasensitive detector for beta radiations.

    PubMed

    Dugasani, Sreekantha Reddy; Kim, Jang Ah; Kim, Byeonghoon; Joshirao, Pranav; Gnapareddy, Bramaramba; Vyas, Chirag; Kim, Taesung; Park, Sung Ha; Manchanda, Vijay

    2014-02-26

    There is growing demand for the development of efficient ultrasensitive radiation detectors to monitor the doses administered to individuals during therapeutic nuclear medicine which is often based on radiopharmaceuticals, especially those involving beta emitters. Recently biological materials are used in sensors in the nanobio disciplines due to their abilities to detect specific target materials or sites. Artificially designed two-dimensional (2D) DNA lattices grown on a substrate were analyzed after exposure to pure beta emitters, (90)Sr-(90)Y. We studied the Raman spectra and reflected intensities of DNA lattices at various distances from the source with different exposure times. Although beta particles have very low linear energy transfer values, the significant physical and chemical changes observed throughout the extremely thin, ?0.6 nm, DNA lattices suggested the feasibility of using them to develop ultrasensitive detectors of beta radiations. PMID:24476415

  10. Optimized mounting of a polyethylene naphthalate scintillation material in a radiation detector.

    PubMed

    Nakamura, Hidehito; Yamada, Tatsuya; Shirakawa, Yoshiyuki; Kitamura, Hisashi; Shidara, Zenichiro; Yokozuka, Takayuki; Nguyen, Philip; Kanayama, Masaya; Takahashi, Sentaro

    2013-10-01

    Polyethylene naphthalate (PEN) has great potential as a scintillation material for radiation detection. Here the optimum mounting conditions to maximize the light collection efficiency from PEN in a radiation detector are discussed. To this end, we have determined light yields emitted from irradiated PEN for various optical couplings between the substrate and the photodetector, and for various substrate surface treatments. The results demonstrate that light extraction from PEN is more sensitive to the optical couplings due to its high refractive index. We also assessed the extent of radioactive impurities in PEN as background sources and found that the impurities are equivalent to the environmental background level. PMID:23845742

  11. Cosmic radiation dose in aircraft--a neutron track etch detector.

    PubMed

    Vukovi?, B; Radoli?, V; Miklavci?, I; Poje, M; Varga, M; Planini?, J

    2007-01-01

    Cosmic radiation bombards us at high altitude by ionizing particles. The radiation environment is a complex mixture of charged particles of solar and galactic origin, as well as of secondary particles produced in interaction of the galactic cosmic particles with the nuclei of atmosphere of the Earth. The radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard ATR 42 and A 320 aircrafts (flight level of 8 and 11 km, respectively) was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter. The estimated occupational effective dose for the aircraft crew (A 320) working 500 h per year was 1.64 mSv. Other experiments, or dose rate measurements with the neutron dosimeter, consisting of LR-115 track detector and boron foil BN-1 or 10B converter, were performed on five intercontinental flights. Comparison of the dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level showed that the neutron component carried about 50% of the total dose. The dose rate measurements on the flights from the Middle Europe to the South and Middle America, then to Korea and Japan, showed that the flights over or near the equator region carried less dose rate; this was in accordance with the known geomagnetic latitude effect. PMID:17600597

  12. Signal and noise of diamond pixel detectors at high radiation fluences

    NASA Astrophysics Data System (ADS)

    Tsung, J.-W.; Havranek, M.; Hügging, F.; Kagan, H.; Krüger, H.; Wermes, N.

    2012-09-01

    CVD diamond is an attractive material option for LHC vertex detectors mainly because of its strong radiation-hardness causal to its large band gap and strong lattice. In particular, pixel detectors operating close to the interaction point profit from tiny leakage currents and small pixel capacitances of diamond resulting in low noise figures when compared to silicon. On the other hand, the charge signal from traversing high energy particles is smaller in diamond than in silicon by a factor of about 2.2. Therefore, a quantitative determination of the signal-to-noise ratio (S/N) of diamond in comparison with silicon at fluences in excess of 1015 neq cm-2, which are expected for the LHC upgrade, is important. Based on measurements of irradiated diamond sensors and the FE-I4 pixel readout chip design and performance, we determine the signal and the noise of diamond pixel detectors irradiated with high particle fluences. To characterize the effect of the radiation damage on the materials and the signal decrease, the change of the mean free path ?e/h of the charge carriers is determined as a function of irradiation fluence. We make use of the FE-I4 pixel chip developed for ATLAS upgrades to realistically estimate the expected noise figures: the expected leakage current at a given fluence is taken from calibrated calculations and the pixel capacitance is measured using a purposely developed chip (PixCap). We compare the resulting S/N figures with those for planar silicon pixel detectors using published charge loss measurements and the same extrapolation methods as for diamond. It is shown that the expected S/N of a diamond pixel detector with pixel pitches typical for LHC, exceeds that of planar silicon pixels at fluences beyond 1015 particles cm-2, the exact value only depending on the maximum operation voltage assumed for irradiated silicon pixel detectors.

  13. The response time of GaN photoconductive detector under various ultraviolet-radiation intensities

    Microsoft Academic Search

    Jintong Xu; Yinwen Tang; Xiangyang Li; Haimei Gong; Degang Zhao

    2005-01-01

    The persistent photoconductivity (PPC) effect was generally observed in many III-V compound semiconductors and it was always related to yellow luminescence. In this paper, the PPC effect in unintentionally doped GaN was investigated. The GaN photoconductive detector response time measured by changing the chopper frequency of modulator was studied under various ultraviolet-radiation intensities. The maximum value of UV intensities used

  14. Developing Si(Li) nuclear radiation detectors by pulsed electric field treatment

    Microsoft Academic Search

    R. A. Muminov; S. A. Radzhapov; A. K. Saimbetov

    2009-01-01

    Fabrication of Si(Li) nuclear radiation detectors using lithium ion drift under the action of a pulsed electric field is considered.\\u000a Optimum treatment regime parameters are determined, including the pulse amplitude, duration, and repetition rate. Experimental\\u000a data are presented, which show that the ion drift in a pulsed electric field decreases the semiconductor bulk compensation\\u000a time by a factor of two

  15. Performance of lead iodide nuclear radiation detectors with the introduction of rare earth elements

    Microsoft Academic Search

    Mahmoud Hassan; Marie Matuchova; Karel Zdansky

    2006-01-01

    Lead iodide has been recognized as a promising material for room temperature radiation detectors. It has a wide band-gap (?\\u000a 2.3 eV), high atomic numbers (82, 53) and it is environmentally very stable compared to mercuric iodide. Electrical and optical\\u000a properties of lead iodide grown crystals purified under the influence of selected rare earth elements have been investigated.\\u000a Photo-luminescence and

  16. Semi-insulating LEC GaAs as a material for radiation detectors: materials science issues

    Microsoft Academic Search

    A. V. Markov; M. V. Mezhennyi; A. Y. Polyakov; N. B. Smirnov; A. V. Govorkov; V. K. Eremin; E. M. Verbitskaya; V. N. Gavrin; Y. P. Kozlova; Y. P. Veretenkin; T. J. Bowles

    2001-01-01

    Semi-insulating (SI) GaAs is now being reconsidered as a promising material for radiation detectors, mostly due to greatly improved quality of the material. In this paper we shall describe the properties of the state-of-the-art SI GaAs crystals grown by LEC method as relevant for such applications. Specifically, we shall concentrate on the assessment of the spectra and density of residual

  17. Development of radiation tolerant semiconductor detectors for the Super-LHC

    Microsoft Academic Search

    M. Moll; J. Adey; A. Al-Ajili; G. Alfieri; P. P. Allport; M. Artuso; S. Assouak; B. S. Avset; L. Barabash; A. Barcz; R. Bates; S. F. Biagi; G. M. Bilei; D. Bisello; A. Blue; A. Blumenau; V. Boisvert; G. Bolla; G. Bondarenko; E. Borchi; L. Borrello; D. Bortoletto; M. Boscardin; L. Bosisio; T. J. V. Bowcock; T. J. Brodbeck; J. Broz; M. Bruzzi; A. Brzozowski; M. Buda; P. Buhmann; C. Buttar; F. Campabadal; D. Campbell; A. Candelori; G. Casse; A. Cavallini; S. Charron; A. Chilingarov; D. Chren; V. Cindro; P. Collins; R. Coluccia; D. Contarato; J. Coutinho; D. Creanza; W. Cunningham; G.-F. Dalla Betta; I. Dawson; W. de Boer; M. De Palma; R. Demina; P. Dervan; S. Dittongo; Z. Dolezal; A. Dolgolenko; T. Eberlein; V. Eremin; C. Fall; F. Fasolo; F. Fizzotti; C. Fleta; E. Focardi; E. Forton; E. Fretwurst; C. Garcia; J. E. Garcia-Navarro; E. Gaubas; M.-H. Genest; K. A. Gill; K. Giolo; M. Glaser; C. Goessling; V. Golovine; S. González Sevilla; I. Gorelov; J. Goss; A. Gouldwell Bates; G. Grégoire; P. Gregori; E. Grigoriev; A. A. Grillo; A. Groza; J. Guskov; L. Haddad; J. Härkönen; F. Hauler; M. Hoeferkamp; F. Hönniger; T. Horazdovsky; R. Horisberger; M. Horn; A. Houdayer; B. Hourahine; G. Hughes; I. Ilyashenko; K. Irmscher; A. Ivanov; K. Jarasiunas; K. M. H. Johansen; B. K. Jones; R. Jones; C. Joram; L. Jungermann; E. Kalinina; P. Kaminski; A. Karpenko; A. Karpov; V. Kazlauskiene; V. Kazukauskas; V. Khivrich; V. Khomenkov; J. Kierstead; J. Klaiber-Lodewigs; R. Klingenberga; P. Kodys; Z. Kohout; S. Korjenevski; M. Koski; R. Kozlowski; M. Kozodaev; G. Kramberger; O. Krasel; A. Kuznetsov; S. Kwan; S. Lagomarsino; K. Lassila-Perini; V. Lastovetsky; G. Latino; S. Lazanu; I. Lazanu; A. Lebedev; C. Lebel; K. Leinonen; C. Leroy; Z. Li; G. Lindström; V. Linhart; A. Litovchenko; P. Litovchenko; A. Lo Giudice; M. Lozano; Z. Luczynski; P. Luukka; A. Macchiolo; L. F. Makarenko; I. Mandi?; C. Manfredotti; N. Manna; S. Marti i Garcia; S. Marunko; K. Mathieson; J. Melone; D. Menichelli; A. Messineo; J. Metcalfe; S. Miglio; M. Mikuz; J. Miyamoto; E. Monakhov; F. Moscatelli; D. Naoumov; E. Nossarzewska-Orlowska; J. Nysten; P. Olivero; V. Oshea; T. Palviainen; C. Paolini; C. Parkes; D. Passeri; U. Pein; G. Pellegrini; L. Perera; M. Petasecca; C. Piemonte; G. U. Pignatel; N. Pinho; I. Pintilie; L. Pintilie; L. Polivtsev; P. Polozov; A. Popa; J. Popule; S. Pospisil; A. Pozza; V. Radicci; J. M. Rafí; R. Rando; R. Roeder; T. Rohe; S. Ronchin; C. Rott; A. Roy; A. Ruzin; H. F. W. Sadrozinski; S. Sakalauskas; M. Scaringella; L. Schiavulli; S. Schnetzer; B. Schumm; S. Sciortino; A. Scorzoni; G. Segneri; S. Seidel; A. Seiden; G. Sellberg; P. Sellin; D. Sentenac; I. Shipsey; P. Sicho; T. Sloan; M. Solar; S. Son; B. Sopko; V. Sopko; N. Spencer; J. Stahl; D. Stolze; R. Stone; J. Storasta; N. Strokan; M. Sudzius; B. Surma; A. Suvorov; B. G. Svensson; P. Tipton; M. Tomasek; A. Tsvetkov; E. Tuominen; E. Tuovinen; T. Tuuva; M. Tylchin; H. Uebersee; J. Uher; M. Ullán; J. V. Vaitkus; J. Velthuis; E. Verbitskaya; V. Vrba; G. Wagner; I. Wilhelm; S. Worm; V. Wright; R. Wunstorf; Y. Yiuri; P. Zabierowski; A. Zaluzhny; M. Zavrtanik; M. Zen; V. Zhukov; N. Zorzi

    2005-01-01

    The envisaged upgrade of the Large Hadron Collider (LHC) at CERN towards the Super-LHC (SLHC) with a 10 times increased luminosity of 1035cm?2s?1 will present severe challenges for the tracking detectors of the SLHC experiments. Unprecedented high radiation levels and track densities and a reduced bunch crossing time in the order of 10ns as well as the need for cost

  18. Investigation of epitaxial silicon layers as a material for radiation hardened silicon detectors

    Microsoft Academic Search

    Z. Li; V. Eremin; I. Ilyashenko; A. Ivanov; E. Verbitskaya

    1998-01-01

    Epitaxial grown thick layers (⩾100 ?m) of high resistivity silicon (Epi-Si) have been investigated as a possible candidate for radiation hardened material for detectors in high-energy physics. As grown Epi-Si layers contain high concentrations (up to 2·1012 cm-3) of deep levels compared with that in standard high resistivity bulk Si. After irradiation of test diodes by protons (Ep=24 GeV) with

  19. A low noise FET with integrated charge restoration for radiation detectors

    Microsoft Academic Search

    T. Nashoishibi; G. White

    1990-01-01

    A novel pulsed, nonoptical, reset technique for use in charge-sensitive amplifiers and radiation detectors is described. The first-stage FET and charge restoration are integrated into one five-terminal device called the Pentafet. A pulse of minority carriers is injected directly into the channel of the FET. The technique is fast, and there are no aftereffects on the operation of the FET.

  20. Silicon PIN radiation detectors with on-chip front-end junction field effect transistors

    Microsoft Academic Search

    G. F. Dalla Betta; G. Verzellesi; M. Boscardin; L. Bosisio; G. U. Pignatel; L. Ferrario; M. Zen; G. Soncini

    1998-01-01

    We report on the latest results obtained from the development of a fabrication technology for PIN radiation detectors with on-chip front-end junction field effect transistors (JFETs) integrated on high-resistivity, FZ silicon. P-doped polysilicon back-side gettering prevented carrier lifetime degradation in spite of the relatively high thermal budget characterizing the fabrication process, allowing very low leakage currents (?1nA\\/cm2 at full depletion)

  1. Effect of surface preparation technique on the radiation detector performance of CdZnTe

    Microsoft Academic Search

    M. C. Duff; D. B. Hunter; A. Burger; M. Groza; V. Buliga; D. R. Black

    2008-01-01

    Synthetic CdZnTe (CZT) semiconducting crystals are highly suitable for the room temperature-based detection of gamma radiation. The surface preparation of Au contacts on surfaces of CZT detectors is typically conducted after (1) polishing to remove artifacts from crystal sectioning and (2) chemical etching, which removes residual mechanical surface damage however etching results in a Te rich surface layer that is

  2. First-principles study of defects and carrier compensation in semiconductor radiation detector materials

    SciTech Connect

    Du, Mao-Hua [ORNL; Takenaka, Hiroyuki [ORNL; Singh, David J [ORNL

    2009-01-01

    We discuss defect engineering strategies in radiation detector materials. The goal is to increase resistivity by defect-induced Fermi level pinning without causing defect-induced reductions in the carrier drifting length. We show calculated properties of various intrinsic defects and impurities in CdTe. We suggest that the defect complex of a hydrogen atom and an isovalent impurity on an anion site may be an excellent candidate in many semiconductors for Fermi level pinning without carrier trapping.

  3. The iQID camera: An ionizing-radiation quantum imaging detector

    PubMed Central

    Miller, Brian W.; Gregory, Stephanie J.; Fuller, Erin S.; Barrett, Harrison H.; Barber, H. Bradford; Furenlid, Lars R.

    2015-01-01

    We have developed and tested a novel, ionizing-radiation Quantum Imaging Detector (iQID). This scintillation-based detector was originally developed as a high-resolution gamma-ray imager, called BazookaSPECT, for use in single-photon emission computed tomography (SPECT). Recently, we have investigated the detector’s response and imaging potential with other forms of ionizing radiation including alpha, neutron, beta, and fission fragment particles. The confirmed response to this broad range of ionizing radiation has prompted its new title. The principle operation of the iQID camera involves coupling a scintillator to an image intensifier. The scintillation light generated by particle interactions is optically amplified by the intensifier and then re-imaged onto a CCD/CMOS camera sensor. The intensifier provides sufficient optical gain that practically any CCD/CMOS camera can be used to image ionizing radiation. The spatial location and energy of individual particles are estimated on an event-by-event basis in real time using image analysis algorithms on high-performance graphics processing hardware. Distinguishing features of the iQID camera include portability, large active areas, excellent detection efficiency for charged particles, and high spatial resolution (tens of microns). Although modest, iQID has energy resolution that is sufficient to discriminate between particles. Additionally, spatial features of individual events can be used for particle discrimination. An important iQID imaging application that has recently been developed is real-time, single-particle digital autoradiography. We present the latest results and discuss potential applications.

  4. Monte Carlo Study of a Mosfet Detector Response Applied to X-Ray Microbeam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    de Felici, M.; Felici, R.; Sanchez Del Rio, M.; Dilmanian, A.; Ferreo, C.

    2004-07-01

    EGS4 Monte Carlo calculations of the dose deposited by array of microbeams, used for the Microbeam Radiation Therapy technique, are presented. The sensitivity of the results to the experimental parameters (incident beam energy, beam array dimensions and spacing) has been assessed. The effects of the photon beam polarization and energy cut-off have also been investigated. The response of a Silicon MOSFET detector of micrometric dimensions, placed inside a phantom made of two homogeneous media (water and PMMA), has been simulated.

  5. Towards thin-film self-powered radiation detectors employing disparate conductive layers

    NASA Astrophysics Data System (ADS)

    Brivio, D.; Sajo, E.; Zygmanski, P.

    2015-06-01

    A new class of self-powered thin film radiation detectors is experimentally explored via their IV-curve characteristics. These detectors are parallel-plane microstructures composed of disparate atomic number (Z) thin-film electrodes separated by air gaps. Large radiation-induced electron currents (RIC) are observed for zero external voltage bias. Compared to ionization chambers (composed of macroscopic non-disparate low-Z electrodes), this anomalous behavior is due to two independent effects: traversal of fast electrons leaking from the high-Z cathodes and the auto-collection of ionization electrons from the air gap due to the presence of contact potential. The zero voltage current reaches up to 80% of the saturation current measured for non-zero bias voltages. The magnitude of saturation currents increases with the total anode and cathode atomic numbers. The stopping potentials (i.e., external voltage bias resulting in zero RIC current) correspond to the differences in the electrodes’ work functions (the contact potential) modified by the contributions from the fast electron current formed by the leaking electrons. These features make the thin film detector attractive for applications in x-ray medical or industrial imaging, dosimetry and radiation protection.

  6. Reconstruction of charged particle fluxes detected by the Radiation Assessment Detector onboard of MSL

    NASA Astrophysics Data System (ADS)

    Guo, J.; Wimmer-Schweingruber, R. F.; Hassler, D.; Zeitlin, C. J.; Ehresmann, B.; Kohler, J.; Boehm, E.; Appel, J. K.; Lohf, H.; Boettcher, S.; Burmeister, S.; Rafkin, S. C.; Kharytonov, A.; Martin-Garcia, C.; Matthiae, D.; Reitz, G.

    2013-12-01

    One of the main science objectives of the Mars Science Laboratory (MSL) is to help planning future human exploration to Mars by constraining the radiation environment during the cruise phase and on the planet's surface. During the 253-day, 560 million km cruise to Mars, the Radiation Assessment Detector, RAD made detailed measurements of the energy spectrum deposited by energetic particles from space and scattered within the spacecraft. Two types of radiation pose potential health risks to astronauts in deep space: a prolonged low-dose exposure to Galactic Cosmic Rays (GCRs) and short-term exposures to the Solar Energetic Particles (SEPs). On the surface of Mars such energetic particles penetrate through its thin atmosphere and generate secondary particles that can also result harms to humans. In order to interpret the energetic charged particle flux coming into the detector, we have developed the Detector Response Function (DRF) using GEANT 4 simulations and employed a Maximum likelihood inversion technique to invert the detected energy spectrum. This method has been applied to RAD detection of GCRs and secondary charged particles on the Martian surface, giving us an unique insight into their energy fluxes. The spectra of the stopping particle fluxes (hydrogen and helium) are also directly obtained from RAD observations and compared with the inversion results.

  7. Nuclear Instruments and Methods in Physics Research A 419 (1998) 556--569 Radiation damage of silicon strip detectors in the NA50 experiment

    E-print Network

    Ramello, Luciano

    1998-01-01

    Nuclear Instruments and Methods in Physics Research A 419 (1998) 556--569 Radiation damage to 20 Mrad, with a very non-uniform radiation spatial distribution. Radiation effects in the detectors; Radiation damage 1. Introduction The multiplicity detector in the NA50 experi- ment [1] is one of very few

  8. High-energy proton radiation damage of high-purity germanium detectors

    NASA Technical Reports Server (NTRS)

    Pehl, R. H.; Varnell, L. S.; Metzger, A. E.

    1978-01-01

    Quantitative studies of radiation damage in high-purity germanium gamma-ray detectors due to high-energy charged particles have been carried out; two 1.0 cm thick planar detectors were irradiated by 6 GeV/c protons. Under proton bombardment, degradation in the energy resolution was found to begin below 7 x 10 to the 7th protons/sq cm and increased proportionately in both detectors until the experiment was terminated at a total flux of 5.7 x 10 to the 8th protons/sq cm, equivalent to about a six year exposure to cosmic-ray protons in space. At the end of the irradiation, the FWHM resolution measured at 1332 keV stood at 8.5 and 13.6 keV, with both detectors of only marginal utility as a spectrometer due to the severe tailing caused by charge trapping. Annealing these detectors after proton damage was found to be much easier than after neutron damage.

  9. Control of electric field in CdZnTe radiation detectors by above-bandgap light

    NASA Astrophysics Data System (ADS)

    Franc, J.; D?di?, V.; Rejhon, M.; Zázvorka, J.; Praus, P.; Touš, J.; Sellin, P. J.

    2015-04-01

    We have studied the possibility of above bandgap light induced depolarization of CdZnTe planar radiation detector operating under high flux of X-rays by Pockels effect measurements. In this contribution, we show a similar influence of X-rays at 80 kVp and LED with a wavelength of 910 nm irradiating the cathode on polarization of the detector due to an accumulation of a positive space charge of trapped photo-generated holes. We have observed the depolarization of the detector under simultaneous cathode-site illumination with excitation LED at 910 nm and depolarization above bandgap LED at 640 nm caused by trapping of drifting photo-generated electrons. Although the detector current is quite high during this depolarization, we have observed that it decreases relatively fast to its initial value after switching off the depolarizing light. In order to get detailed information about physical processes present during polarization and depolarization and, moreover, about associated deep levels, we have performed the Pockels effect infrared spectral scanning measurements of the detector without illumination and under illumination in polarized and optically depolarized states.

  10. Development of an Alpha/Beta/Gamma Phoswich-Based Radiation Detector for Nuclear Waste Stream Cleanup Processes

    SciTech Connect

    William H. Miller; Tushar Ghosh

    2004-03-10

    The goal of this research is to design, build and test a phoswich-based radiation detector for simultaneously monitoring all radioactive components in the effluent resulting from the cleanup of nuclear waste

  11. The Mars Science Laboratory (MSL) Radiation Assessment Detector (RAD) and Implications for IRAS on ExoMars

    Microsoft Academic Search

    Robert F. Wimmer-Schweingruber; Cary Zeitlin; Stephan Boettcher; Cesar Martin; Onno Kortmann; Arik Posner; Guenther Reitz; Eckhardt Boehm; Scot Rafkin; Soenke Burmeister; Donald M. Hassler

    2008-01-01

    The Radiation Assessment Detector (RAD) on NASA's Mars Science Laboratory mission is being built to characterize the broad-spectrum of the surface radiation environment, including galactic cosmic radiation, solar proton events, and secondary neutrons. This overarching mission goal is met by RADs science objectives 1-5: 1.)Characterize the energetic particle spectrum incident at the surface of Mars, including direct and indirect radiation

  12. Single charge carrier type sensing with a parallel strip pseudo-Frisch-grid CdZnTe semiconductor radiation detector

    Microsoft Academic Search

    D. S. McGregor; H. A. Seifert; D. K. Wehe; R. A. Rojeski

    Wide band gap compound semiconducting materials of- fer great promise for use as room temperature operated ra- diation detectors. The most common semiconductor radiation detector design incorporates the use of a semiconducting block of material with metal contacts applied at opposite ends of the block. A voltage is applied across the block, which produces an internal electric field capable of

  13. Charge transfer in the presence of a layer of trapping centers in semiconductor SiC ionizing radiation detectors

    Microsoft Academic Search

    A. M. Ivanov; E. V. Kalinina; N. B. Strokan

    2008-01-01

    The formation of a response signal in the presence of a layer of trapping centers in semiconductor SiC ionizing radiation detectors is considered on the basis of a new model. Since the trapping layer is situated near the detector surface, nuclear particles that possess long tracks partly generate a charge behind this layer. Under certain conditions, the proposed model leads

  14. Simultaneous measurement of neutron and gamma-ray radiation levels from a TRIGA reactor core using silicon carbide semiconductor detectors

    Microsoft Academic Search

    A. R. Dulloo; F. H. Ruddy; J. G. Seidel; C. Davison; T. Flinchbaugh; T. Daubenspeck

    1998-01-01

    The ability of a SiC detector to measure neutron and gamma radiation levels in a TRIGA reactor's mixed neutron\\/gamma field was demonstrated. Linear responses to an epicadmium neutron fluence rate (up to 3×107 cm-2 s-1) and to a gamma dose rate (0.6-234 krad-Si h-1) were obtained with the detector. Axial profiles of the reactor core's neutron and gamma-ray radiation levels

  15. Development of a fast radiation detector based on barium fluoride scintillation crystal.

    PubMed

    Han, Hetong; Zhang, Zichuan; Weng, Xiufeng; Liu, Junhong; Guan, Xingyin; Zhang, Kan; Li, Gang

    2013-07-01

    Barium fluoride (BaF2) is an inorganic scintillation material used for the detection of X?gamma radiation due to its relatively high density, equivalent atomic number, radiation hardness, and high luminescence. BaF2 has a potential capacity to be used in gamma ray timing experiments due to the prompt decay emission components. It is known that the light output from BaF2 has three decay components: two prompt of those at approximately 195 nm and 220 nm with a decay constant around 600-800 ps and a more intense, slow component at approximately 310 nm with a decay constant around 630 ns which hinders fast timing experiments. We report here the development of a fast radiation detector based on a BaF2 scintillation crystal employing a special optical filter device, a multiple reflection multi-path ultraviolet region short-wavelength pass light guides (MRMP-short pass filter) by using selective reflection technique, for which the intensity of the slow component is reduced to less than 1%. The methods used for this study provide a novel way to design radiation detector by utilizing scintillation crystal with several emission bands. PMID:23902059

  16. Development of a fast radiation detector based on barium fluoride scintillation crystal

    SciTech Connect

    Han, Hetong [Northwest Institute of Nuclear Technology, NINT, Xi'an 710024, Shaanxi (China) [Northwest Institute of Nuclear Technology, NINT, Xi'an 710024, Shaanxi (China); School of Nuclear Science and Technology, Xi'an Jiaotong University, XJTU, Xi'an 710049, Shaanxi (China); Zhang, Zichuan; Weng, Xiufeng; Liu, Junhong; Zhang, Kan; Li, Gang [Northwest Institute of Nuclear Technology, NINT, Xi'an 710024, Shaanxi (China)] [Northwest Institute of Nuclear Technology, NINT, Xi'an 710024, Shaanxi (China); Guan, Xingyin [School of Nuclear Science and Technology, Xi'an Jiaotong University, XJTU, Xi'an 710049, Shaanxi (China)] [School of Nuclear Science and Technology, Xi'an Jiaotong University, XJTU, Xi'an 710049, Shaanxi (China)

    2013-07-15

    Barium fluoride (BaF{sub 2}) is an inorganic scintillation material used for the detection of X/gamma radiation due to its relatively high density, equivalent atomic number, radiation hardness, and high luminescence. BaF{sub 2} has a potential capacity to be used in gamma ray timing experiments due to the prompt decay emission components. It is known that the light output from BaF{sub 2} has three decay components: two prompt of those at approximately 195 nm and 220 nm with a decay constant around 600-800 ps and a more intense, slow component at approximately 310 nm with a decay constant around 630 ns which hinders fast timing experiments. We report here the development of a fast radiation detector based on a BaF{sub 2} scintillation crystal employing a special optical filter device, a multiple reflection multi-path ultraviolet region short-wavelength pass light guides (MRMP-short pass filter) by using selective reflection technique, for which the intensity of the slow component is reduced to less than 1%. The methods used for this study provide a novel way to design radiation detector by utilizing scintillation crystal with several emission bands.

  17. The effects of proton-induced radiation damage on compound-semiconductor X-ray detectors

    NASA Astrophysics Data System (ADS)

    Owens, Alan; Alha, Lauri; Andersson, Hans; Bavdaz, Marcos; Brammertz, Guy; Helariutta, Kerttuli; Peacock, Anthony; Lämsä, V.; Nenonen, Seppo A. A.

    2004-09-01

    We report the results of a series of experiments designed to assess the relative radiation hardness of a range of compound semiconductor X-ray detectors. The specific compounds tested were GaAs, InP, CdZnTe, HgI2 and TlBr, along with an elemental Si device. To allow meaningful comparisons, all devices were of a similar size and, with the exception of the InP detector, had sub-keV energy resolution at 5.9 keV. The irradiations were carried out using the University of Helsinki"s Cyclone 10/5 10 MeV proton cyclotron. Each detector was given six consecutive exposures - the integral fluences being; 2.66 x 109 p cm-2, 7.98 x 109 p cm-2, 2.65 x 1010 p cm-2, 7.97 x 1010 p cm-2, 1.59 x 1011 p cm-2, and 2.65 x 1011 p cm-2, respectively. In Si, these correspond to absorbed radiation doses of 2, 6, 20, 60, 120 and 200 krads. During the exposures, the detectors were kept unbiased and at room temperature. After each irradiation, the effects of the exposure were assessed, both at room temperature and at a reduced temperature using 55Fe, 109Cd and 241Am radioactive sources. It was found that with the exception of the HgI2 and TlBr detectors all materials showed varying degrees of damage effects.

  18. Scattered radiation in flat-detector based cone-beam CT: analysis of voxelized patient simulations

    NASA Astrophysics Data System (ADS)

    Wiegert, Jens; Bertram, Matthias

    2006-03-01

    This paper presents a systematic assessment of scattered radiation in flat-detector based cone-beam CT. The analysis is based on simulated scatter projections of voxelized CT images of different body regions allowing to accurately quantify scattered radiation of realistic and clinically relevant patient geometries. Using analytically computed primary projection data of high spatial resolution in combination with Monte-Carlo simulated scattered radiation, practically noise-free reference data sets are computed with and without inclusion of scatter. The impact of scatter is studied both in the projection data and in the reconstructed volume for the head, thorax, and pelvis regions. Currently available anti-scatter grid geometries do not sufficiently compensate scatter induced cupping and streak artifacts, requiring additional software-based scatter correction. The required accuracy of scatter compensation approaches increases with increasing patient size.

  19. Charged Particle Measurements with the Mars Science Laboratory's Radiation Assessment Detector (MSL/RAD)

    NASA Astrophysics Data System (ADS)

    Ehresmann, B.; Hassler, D.; Zeitlin, C. J.; Kohler, J.; Wimmer-Schweingruber, R. F.; Appel, J. K.; Boehm, E.; Böttcher, S. I.; Brinza, D. E.; Burmeister, S.; Guo, J.; Lohf, H.; Martin-Garcia, C.; Matthiae, D.; Posner, A.; Rafkin, S. C.; Reitz, G.

    2014-12-01

    Since the Curiosity rover's landing in Gale crater on the surface of Mars, the Radiation Assessment Detector (RAD) on board the rover has been conducting the first-ever measurements of the Martian surface radiation field. This field is induced by Galactic Cosmic Rays (GCRs) and their interactions with the atoms of the Martian atmosphere and soil. Furthermore, sporadic Solar Energetic Particle (SEP) events can lead to large, but short-term enhancements in the intensity of the radiation field. A large part of the radiation environment is made up of charged particles, e.g., ions and their isotopes, electrons, and positrons amongst others. There are mainly two factors influencing the surface radiation field: the modulation of the incoming GCR flux due to the solar magnetic field correlating with the solar cycle; the amount of atmospheric column mass above Gale crater resulting in changes of GCR penetration depth into the atmosphere, as well as influencing the secondary particle production rate. Here, we focus on the temporal evolution of the radiation environment since the landing, analyzing changes in the measured particle spectra for different phases in the Martian seasonal cycle and solar activity. Furthermore, we present enhancements in the proton flux during directly observed SEP events.

  20. Investigation of epitaxial silicon layers as a material for radiation hardened silicon detectors

    SciTech Connect

    Li, Z. [Brookhaven National Lab., Upton, NY (United States); Eremin, V.; Ilyashenko, I.; Ivanov, A. [Russian Academy of Sciences, St-Petersburg (Russian Federation). Ioffe Physico-Technical Institute] [and others

    1997-11-01

    Epitaxial grown thick layers (>100 {mu}m) of high resistivity silicon (Epi-Si) have been investigated as a possible candidate of radiation hardened material for detectors for high-energy physics. As grown Epi-Si layers contain high concentration (up to 2{center_dot}10{sup 12} cm{sup {minus}3}) of deep levels compared with that in standard high resistivity bulk Si. After irradiation of test diodes by protons (E{sub p} = 24 GeV) with a fluence of 1.5{center_dot}10{sup 11} cm{sup {minus}2}, no additional radiation induced deep traps have been detected. A reasonable explanation is that there is a sink of primary radiation induced defects, in epitaxial layers. The {open_quotes}sinking{close_quotes} process, however, becomes non-effective at high radiation fluences (10{sup 14} cm{sup {minus}2}) due to saturation of epitaxial defects by high concentration of radiation induced ones. As a result, at neutron fluence of 1{center_dot}10{sup 14}cm{sup {minus}2} the deep level spectrum corresponds to well-known spectrum of radiation induced defects in high resistivity bulk Si. The net effective concentration in the space charge region equals to 3{center_dot}10{sup 12} cm{sup {minus}3} after 3 months of room temperature storage and reveals similar annealing behavior for epitaxial as compared to bulk silicon.

  1. Investigation of epitaxial silicon layers as a material for radiation hardened silicon detectors

    SciTech Connect

    Li, Z. [Brookhaven National Lab., Upton, NY (United States); Eremin, V.; Ilyashenko, I.; Ivanov, A.; Verbitskaya, E. [Russian Academy of Sciences, St. Petersburg (Russian Federation). Ioffe Physico-Technical Inst.; CERN RD-48 ROSE Collaboration

    1997-12-01

    Epitaxial grown thick layers ({ge} 100 micrometers) of high resistivity silicon (Epi-Si) have been investigated as a possible candidate of radiation hardened material for detectors for high-energy physics. As grown Epi-Si layers contain high concentration (up to 2 {times} 10{sup 12} cm{sup {minus}3}) of deep levels compared with that in standard high resistivity bulk Si. After irradiation of test diodes by protons (E{sub p} = 24 GeV) with a fluence of 1.5 {times} 10{sup 11} cm{sup {minus}2}, no additional radiation induced deep traps have been detected. A reasonable explanation is that there is a sink of primary radiation induced defects (interstitial and vacancies), possibly by as-grown defects, in epitaxial layers. The ``sinking`` process, however, becomes non-effective at high radiation fluences (10{sup 14} cm{sup {minus}2}) due to saturation of epitaxial defects by high concentration of radiation induced ones. As a result, at neutron fluence of 1 {times} 10{sup 14} cm{sup {minus}2} the deep level spectrum corresponds to well-known spectrum of radiation induced defects in high resistivity bulk Si. The net effective concentration in the space charge region equals to 3 {times} 10{sup 12} cm{sup {minus}3} after 3 months of room temperature storage and reveals similar annealing behavior for epitaxial as compared to bulk silicon.

  2. Investigation of epitaxial silicon layers as a material for radiation hardened silicon detectors

    SciTech Connect

    Li, Z. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States); Eremin, V.; Ilyashenko, I.; Ivanov, A.; Verbitskaya, E. [Russian Academy of Sciences, St. Petersburg (Russian Federation). Ioffe Physico-Technical Inst.] [Russian Academy of Sciences, St. Petersburg (Russian Federation). Ioffe Physico-Technical Inst.

    1998-06-01

    Epitaxial grown thick layers ({ge} 100 {micro}m) of high resistivity silicon (Epi-Si) have been investigated as a possible candidate for radiation hardened material for detectors in high-energy physics. As grown Epi-Si layers contain high concentrations (up to 2 {times} 10{sup 12} cm{sup {minus}3}) of deep levels compared with that in standard high resistivity bulk Si. After irradiation of test diodes by protons (E{sub p} = 24 GeV) with a fluence of 15 {times} 10{sup 11} cm{sup {minus}2}, no additional radiation induced deep traps have been detected. A reasonable explanation is that there is a sink of primary radiation induced defects (interstitial and vacancies), possibly by as-grown defects, in epitaxial layers. The sinking process, however, becomes non-effective at high radiation fluences (10{sup 14} cm{sup {minus}2}) due to saturation of epitaxial defects by high concentration of radiation induced ones. As a result, at neutron fluences of 1 {times} 10{sup 14} cm{sup {minus}2} the deep level spectrum corresponds to well-known spectrum of radiation induced defects in high resistivity bulk Si. The net effective concentration in the space charge region equals to 3 {times} 10{sup 12} cm{sup {minus}3} after 3 months of room temperature storage and reveals similar annealing behavior for epitaxial as compared to bulk silicon.

  3. Nuclear reactor pulse tracing using a CdZnTe electro-optic radiation detector

    NASA Astrophysics Data System (ADS)

    Nelson, Kyle A.; Geuther, Jeffrey A.; Neihart, James L.; Riedel, Todd A.; Rojeski, Ronald A.; Ugorowski, Philip B.; McGregor, Douglas S.

    2012-07-01

    CdZnTe has previously been shown to operate as an electro-optic radiation detector by utilizing the Pockels effect to measure steady-state nuclear reactor power levels. In the present work, the detector response to reactor power excursion experiments was investigated. Peak power levels during an excursion were predicted to be between 965 MW and 1009 MW using the Fuchs-Nordheim and Fuchs-Hansen models and confirmed with experimental data from the Kansas State University TRIGA Mark II nuclear reactor. The experimental arrangement of the Pockels cell detector includes collimated laser light passing through a transparent birefringent crystal, located between crossed polarizers, and focused upon a photodiode. The birefringent crystal, CdZnTe in this case, is placed in a neutron beam emanating from a nuclear reactor beam port. After obtaining the voltage-dependent Pockels characteristic response curve with a photodiode, neutron measurements were conducted from reactor pulses with the Pockels cell set at the 1/4 and 3/4 wave bias voltages. The detector responses to nuclear reactor pulses were recorded in real-time using data logging electronics, each showing a sharp increase in photodiode current for the 1/4 wave bias, and a sharp decrease in photodiode current for the 3/4 wave bias. The polarizers were readjusted to equal angles in which the maximum light transmission occurred at 0 V bias, thereby, inverting the detector response to reactor pulses. A high sample rate oscilloscope was also used to more accurately measure the FWHM of the pulse from the electro-optic detector, 64 ms, and is compared to the experimentally obtained FWHM of 16.0 ms obtained with the 10B-lined counter.

  4. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    SciTech Connect

    Cho, Gyuseong

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was {approximately}400 MHz and the noise charge {approximately}1000 electrons at a 1 {mu}sec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of {approximately}0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  5. Laboratory tests of pulse shape discrimination techniques for correcting the effects of radiation damage in germanium coaxial detectors

    NASA Astrophysics Data System (ADS)

    Boggs, S. E.; Hull, E. L.; Lin, R. P.; Madden, N. W.; McBride, S.; Pehl, R. H.; Primbsch, J. H.; Slassi-Sennou, S.

    2000-04-01

    A reverse-electrode closed-end germanium coaxial detector was irradiated with 183-MeV neutrons to evaluate the value of Pulse Shape Discrimination (PSD) techniques in restoring the energy resolution and line shape of the radiation damaged detector. Two consecutive irradiations were performed for total fluences of 5.0×10 8 and 10.4×10 8 n/ cm2, with PSD tests performed after each irradiation. These irradiations degraded the energy resolution and line shapes; however, PSD corrections significantly restored the performance, even after severe damage. These PSD techniques delay and potentially eliminate, in some experimental situations, the need to anneal germanium detectors in damaging radiation environments.

  6. New detector technology to detect and determine the angle of arrival of collimated radiation

    NASA Astrophysics Data System (ADS)

    Cantin, Andre; Dubois, Jacques

    1998-09-01

    Miniaturized digital High Angular Resolution Laser Irradiation Detector (HARLIDTM) modules have been developed by the Defence Research Establishment Valcartier in collaboration with EG&G Optoelectronics Canada. These modules are designed to locate a collimated beam of radiation, such as a laser, within +/- 1 degree(s) over a 90 degree(s) field of view either in azimuth or elevation. There are presently two versions of HARLID: the 1-band HARLID which is based on Si detectors and is functional within the range of 0.45 to 1.1 micrometers ; and the 2-band HARLID based on Si/InGaAs detectors and is functional within the range of 0.45 to 1.70 micrometers . The principle of operation of this new patented module is based on the use of a Gray code mask to encode the angle of arrival of a laser beam. Military and civilian applications fields include defensive aid suites (Laser Warning Receivers) and platform guidance, alignment and positioning aids, where high angular precision is required. There are other laser detectors on the market, but HARLID has emerged, through laboratory testing and comparative field trials, to be one of the best performers, selling at the lower cost and having the lowest integration encumbrance.

  7. Soft X-Ray Spectrometer Using 100-Pixel STJ Detectors for Synchrotron Radiation

    SciTech Connect

    Shiki, Shigetomo; Zen, Nobuyuki; Ukibe, Masahiro; Ohkubo, Masataka [National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2009-12-16

    Fluorescent X-ray absorption fine structure (XAFS) is an important tool for material analysis, especially for the measurement of chemical states or local structures of elements. Semiconductor detectors are usually used for separating the fluorescent of elements in question from background fluorescence. However, the semiconductor detectors cannot always discriminate K-lines of light elements and L-lines of various elements as different X-ray peaks at an energy range below about 3 keV. Superconducting tunnel junction (STJ) detectors are promising device for the soft X-ray at synchrotron radiation beam lines because of excellent energy resolution, high detection efficiency, and high counting rate. We are constructing a fluorescent X-ray spectrometer having 100-pixel array of STJs with 200 {mu}m square. The array detector is mounted on a liquid cryogen-free {sup 3}He cryostat. The sensitive area is the largest among the superconducting X-ray spectrometers operating at synchrotron beam lines. Each pixel is connected to a room temperature readout circuit that consists of a charge sensitive amplifier and a pulse height analyzer. The spectrometer will achieve a total solid angle of {approx}0.01 sr and a maximum counting rate of more than 1 M count per second. The present status of developments of our fluorescent X-ray spectrometer was reported.

  8. Artificial diamonds as radiation-hard detectors for ultra-fast fission-fragment timing

    NASA Astrophysics Data System (ADS)

    Oberstedt, S.; Borcea, R.; Bry?, T.; Gamboni, Th.; Geerts, W.; Hambsch, F.-J.; Oberstedt, A.; Vidali, M.

    2013-06-01

    In the framework of the construction of the double time-of-flight spectrometer VERDI, where we aim at measuring pre- and post-neutron masses directly and simultaneously, ultra-fast time pick-up detectors based on artificial diamond material were investigated for the first time with fission fragments from 252Cf (0.5 MeV/uradiation fluence was determined up to at least 109 fission-fragments/cm2 together with more than 3.5×109 neutrons/cm2 and 3×1010?-particles/cm2. This fluence is characteristic for fission experiments. The pre-requisite for the observed signal stability is the application of priming of the diamond material with a strong ?-source for about 48 h. The intrinsic timing resolution of a 100 ?m thick polycrystalline CVD diamond detector with a size of 1×1 cm2 was determined to ?int=(283±41) ps by comparison with Monte-Carlo simulations. Using broadband pre-amplifiers, 4-fold segmented detectors of same total size and with a thickness of 180 ?m show an intrinsic timing resolution of ?int=(106±21) ps. This is highly competitive with the best micro-channel plate detectors. Due to the limited and batch-dependent charge collection efficiency of poly-crystalline diamond material, the detection efficiency for fission fragments may be smaller than 100%.

  9. Next Generation Semiconductor-Based Radiation Detectors Using Cadmium Magnesium Telluride

    SciTech Connect

    Trivedi, Sudhir B [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Kutcher, Susan W [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Palsoz, Witold [Brimrose Technology Corporation, Sparks Glencoe, MD (United States); Berding, Martha [SRI International, Menlo Park, CA (United States); Burger, Arnold [Brimrose Technology Corporation, Sparks Glencoe, MD (United States)

    2014-11-17

    The primary objective of Phase I was to perform extensive studies on the purification, crystal growth and annealing procedures of CdMgTe to gain a clear understanding of the basic material properties to enable production of detector material with performance comparable to that of CdZnTe. Brimrose utilized prior experience in the growth and processing of II-VI crystals and produced high purity material and good quality single crystals of CdMgTe. Processing techniques for these crystals including annealing, mechanical and chemical polishing, surface passivation and electrode fabrication were developed. Techniques to characterize pertinent electronic characteristics were developed and gamma ray detectors were fabricated. Feasibility of the development of comprehensive defect modeling in this new class of material was demonstrated by our partner research institute SRI International, to compliment the experimental work. We successfully produced a CdMgTe detector that showed 662 keV gamma response with energy resolution of 3.4% (FWHM) at room temperature, without any additional signal correction. These results are comparable to existing CdZnTe (CZT) technology using the same detector size and testing conditions. We have successfully demonstrated detection of gamma-radiation from various isotopes/sources, using CdMgTe thus clearly proving the feasibility that CdMgTe is an excellent, low-cost alternative to CdZnTe.

  10. Detector control system for the ATLAS Transition Radiation Tracker: architecture and development techniques

    NASA Astrophysics Data System (ADS)

    Bana?, El?bieta; Hajduk, Zbigniew; Olszowska, Jolanta

    2012-05-01

    The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. With ~300000 drift tube proportional counters (straws) filled with stable gas mixture and high voltage biased it provides precise quasi-continuous tracking and particles identification. Safe, coherent and efficient operation of the TRT is fulfilled with the help of the Detector Control System (DCS) running on 11 computers as PVSS (industrial SCADA) projects. Standard industrial and custom developed server applications and protocols are used for reading hardware parameters. Higher level control system layers based on the CERN JCOP framework allow for automatic control procedures, efficient error recognition and handling and provide a synchronization mechanism with the ATLAS data acquisition system. Different data bases are used to store the detector online parameters, the configuration parameters and replicate a subset of them used to flag data quality for physics reconstruction. The TRT DCS is fully integrated with the ATLAS Detector Control System.

  11. Particle Detectors

    NASA Astrophysics Data System (ADS)

    Grupen, Claus; Shwartz, Boris

    2011-09-01

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

  12. Effects of radiation-induced defects on the charge collection efficiency of a silicon carbide particle detector

    NASA Astrophysics Data System (ADS)

    Iwamoto, Naoya; Onoda, Shinobu; Makino, Takahiro; Ohshima, Takeshi; Kojima, Kazutoshi; Nozaki, Shinji

    2013-05-01

    Radiation hardness of 6H silicon carbide (SiC) p+n diode particle detectors has been studied. The charge collection efficiency (CCE) of the detectors decreases with the increased fluence of electrons with energies of 0.2 MeV and higher. Defect X2 with an activation energy of 0.5 eV was found in all detectors which showed the decreased CCE. The decreased CCE was restored to the initial value by thermal annealing of defect X2. It is concluded that defect X2 is responsible for the decreased CCE of 6H-SiC p+n diode particle detectors.

  13. Traceable calibration of a fibre-coupled superconducting nano-wire single photon detector using characterized synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Müller, Ingmar; Klein, Roman M.; Werner, Lutz

    2014-12-01

    Radiometric calibrations of fibre-coupled single photon detectors are experiencing growing demand, especially at the telecommunication wavelengths. In this paper, the radiometric calibration of a fibre-coupled superconducting nano-wire single photon detector at the telecom wavelength 1.55 µm by means of well-characterized synchrotron radiation is described. This substitution method is based on the unique properties of synchrotron radiation and the Metrology Light Source, the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt, and is suitable for fibre-coupled single photon detectors. The Metrology Light Source is used as a light source with a high dynamic range of the radiant power to bridge the radiometric gap occurring in the transition from radiant power measurements and the counting of photons with single photon detectors. Very low uncertainties below 2% have been achieved in the measurement of the detection efficiency of a fibre-coupled superconducting nano-wire single photon detector.

  14. Bidimensional polycrystalline CVD diamond detector for Intensity Modulated Radiation Therapy pre-treatment verifications

    NASA Astrophysics Data System (ADS)

    Zani, M.; Scaringella, M.; Talamonti, C.; De Sio, A.; Pace, E.; Tozzetti, L.; Baldi, A.; Bucciolini, M.; Bruzzi, M.

    2015-03-01

    This study aims at investigating the possible employment for pre-treatment verifications in Intensity Modulated Radiation Therapy (IMRT) of a polycrystalline Chemical Vapour Deposited (pCVD) diamond bidimensional detector. The pCVD device, with an area of 2.5 × 2.5 cm2 (12 × 12 pixels), has been used to measure dose maps of a 10 MVRX prostatic IMRT field. Its response was compared both with a commercial bi-dimensional detector made with silicon and with Treatment Planning System (TPS) calculations.Measurement provided promising results on a map of 1.8 × 12.6 cm2. Absorbed doses measured along IMRT profiles by our device are consistent with the ones acquired with the commercial device and an overall good agreement with respect to the TPS was found for the diamond dosimeter.

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

    NASA Astrophysics Data System (ADS)

    Akopova, A. B.

    We propose to study the radiation environment on board different flight vehicles: cosmos-type satellites, orbital stations, Space Shuttles and civil (sonic and supersonic) aircraft. These investigations will be carried out with single type of passive detector, namely, nuclear photoemulsions (NPE) with adjustable threshold of particle detection within broad range of linear energy transfer (LET) that is done by means of the technique of selective development of NPE exposed in space. These investigations will allow one to determine: • integral spectra of LET of charged particles of cosmic ray (CR) over a wide range from 2.0 to 5x10^4 MeV/cm in biological tissue • differential energy spectra of fast neutrons (1-20 MeV) • estimation of absorbed and equivalent doses from charged and neutral component CR • charge and energy spectra of low energy nuclei (E <=100 MeV) with Z>=2 having in view the extreme hazard radiation to biological objects and microelectronic schemes taken on board inside and outside of these different flight vehicles with exposures from several days to several months. The investigation of radiation environment on board the airplanes depending on the flight parameters will be conducted using emulsions of different sensitivity without any controlling of threshold sensitivity (Akopova et al., 1996). The proposed detector can be used in the joint experiments on the new International Cosmic Station ``Alpha''.

  16. Radiation-hard active CMOS pixel sensors for HL-LHC detector upgrades

    NASA Astrophysics Data System (ADS)

    Backhaus, Malte

    2015-02-01

    The luminosity of the Large Hadron Collider (LHC) will be increased during the Long Shutdown of 2022 and 2023 (LS3) in order to increase the sensitivity of its experiments. A completely new inner detector for the ATLAS experiment needs to be developed to withstand the extremely harsh environment of the upgraded, so-called High-Luminosity LHC (HL-LHC). High radiation hardness as well as granularity is mandatory to cope with the requirements in terms of radiation damage as well as particle occupancy. A new silicon detector concept that uses commercial high voltage and/or high resistivity full complementary metal-oxide-semiconductor (CMOS) processes as active sensor for pixel and/or strip layers has risen high attention, because it potentially provides high radiation hardness and granularity and at the same time reduced price due to the commercial processing and possibly relaxed requirements for the hybridization technique. Results on the first prototypes characterized in a variety of laboratory as well as test beam environments are presented.

  17. A Compact Combinatorial Device for Measurement of Nonlinearity of Radiation Detectors

    NASA Astrophysics Data System (ADS)

    Saunders, P.; White, D. R.; Edgar, H.

    2015-03-01

    A new compact computer-controlled device using a combinatorial technique for measuring the nonlinearity of radiation detectors is described. The device consists of two sets of four beam-splitter cubes optically cemented together and arranged so that radiation from a single source is split into four separate paths, then recombined after passing through one of five neutral density filters placed in each path. This allows for the measurement of 625 approximately equi-spaced inter-related flux levels based on only 16 unknown transmittance values. These can be solved for by least-squares fitting, leaving 609 degrees of freedom remaining to determine the nonlinearity of the detector. A novel aspect of the design is the use of neutral density glass plates optically cemented along all the external faces of the beam-splitter cubes, which act as beam dumps for any reflected or scattered radiation. The cube faces in the desired beam paths have clear glass plates with an anti-reflection coating applied at the wavelength of interest optically cemented to them. Operation at other wavelengths is achieved by simply replacing these plates with plates coated for the new wavelength. The performance of the device has been tested using a silicon photodiode with a collimated 650 nm LED as the source. The results demonstrate that the device is able to measure linearity to better than 1 part in.

  18. Photodiode radiation hardness, lyman-alpha emitting galaxies and photon detection in liquid argon neutrino detectors

    NASA Astrophysics Data System (ADS)

    Baptista, Brian

    My dissertation is comprised of three projects: 1) studies of Lyman-alpha Emitting galaxies (LAEs), 2) radiation hardness studies of InGaAs photodiodes (PDs), and 3) scintillation photon detection in liquid argon (LAr) neutrino detectors. I began work on the project that has now become WFIRST, developing a science case that would use WFIRST after launch for the observation of LAEs. The radiation hardness of PDs was as an effort to support the WFIRST calibration team. When WFIRST was significantly delayed, I joined an R&D effort that applied my skills to work on photon detection in LAr neutrino detectors. I report results on a broadband selection method developed to detect high equivalent width (EW) LAEs. Using photometry from the CFHT-Legacy Survey Deep 2 and 3 fields, I have spectroscopically confirmed 63 z=2.5-3.5 LAEs using the WIYN/Hydra spectrograph. Using UV continuum-fitting techniques I computed properties such as EWs, internal reddening and star formation rates. 62 of my LAEs show evidence to be normal dust-free LAEs. Second, I present an investigation into the effects of ionizing proton radiation on commercial off-the-shelf InGaAs PDs. I developed a monochromator-based test apparatus that utilized NIST-calibrated reference PDs. I tested the PDs for changes to their dark current, relative responsivity as a function of wavelength, and absolute responsivity. I irradiated the test PDs using 30, 52, and 98 MeV protons at the IU Cyclotron Facility. I found the InGaAs PDs showed increased dark current as the fluence increased with no evidence of broadband response degradation at the fluences expected at an L2 orbit and a 10-year mission lifetime. Finally, I detail my efforts on technology development of both optical detector technologies and waveshifting light guide construction for LAr vacuum UV scintillation light. Cryogenic neutrino detectors use photon detection for both accelerator based science and for SNe neutrino detection and proton decay. I have developed waveshifter doped cast acrylic light guides that convert scintillation light and guide the waveshifted light to SiPMs detectors.

  19. High spatial resolution radiation detectors based on hydrogenated amorphous silicon and scintillator

    SciTech Connect

    Jing, T [Univ. of California, Berkeley, CA (United States). Dept. of Engineering-Nuclear Engineering

    1995-05-01

    Hydrogenated amorphous silicon (a-Si:H) as a large-area thin film semiconductor with ease of doping and low-cost fabrication capability has given a new impetus to the field of imaging sensors; its high radiation resistance also makes it a good material for radiation detectors. In addition, large-area microelectronics based on a-Si:H or polysilicon can be made with full integration of peripheral circuits, including readout switches and shift registers on the same substrate. Thin a-Si:H p-i-n photodiodes coupled to suitable scintillators are shown to be suitable for detecting charged particles, electrons, and X-rays. The response speed of CsI/a-Si:H diode combinations to individual particulate radiation is limited by the scintillation light decay since the charge collection time of the diode is very short (< 10ns). The reverse current of the detector is analyzed in term of contact injection, thermal generation, field enhanced emission (Poole-Frenkel effect), and edge leakage. A good collection efficiency for a diode is obtained by optimizing the p layer of the diode thickness and composition. The CsI(Tl) scintillator coupled to an a-Si:H photodiode detector shows a capability for detecting minimum ionizing particles with S/N {approximately}20. In such an arrangement a p-i-n diode is operated in a photovoltaic mode (reverse bias). In addition, a p-i-n diode can also work as a photoconductor under forward bias and produces a gain yield of 3--8 for shaping times of 1 {micro}s. The mechanism of the formation of structured CsI scintillator layers is analyzed. Initial nucleation in the deposited layer is sensitive to the type of substrate medium, with imperfections generally catalyzing nucleation. Therefore, the microgeometry of a patterned substrate has a significant effect on the structure of the CsI growth.

  20. Field emitter type CdTe radiation detector for x-ray imager

    NASA Astrophysics Data System (ADS)

    Sakata, Takuya; Ikeda, Yoshiaki; Shiozawa, Kazufumi; Neo, Yoichiro; Morii, Hisashi; Aoki, Toru; Mimura, Hidenori

    2006-08-01

    We proposed a new addressing method that used a field emitter type electronic source for the radiation imaging detector. We enabled this device to operate room temperature by using Cadmium Telluride (CdTe) diode. In this addressing method, the energy of the electron from electronic source in each pixel was much uniformed and the electron beams can be focused within a micro meter diameter. Therefore, because this proposed device was lead out by field emitter, it was expected to achieve the super-high resolution X-ray imager. In this paper, we used the carbon nanoneedle field emitter, and the proposed device operation was confirmed by verifying principle about one pixel.