WorldWideScience

Sample records for chemical radiation detectors

  1. Radiation detector

    Science.gov (United States)

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  2. Tin Can Radiation Detector.

    Science.gov (United States)

    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)

  3. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  4. Transition Radiation Detectors

    CERN Document Server

    Andronic, A

    2012-01-01

    We review the basic features of transition radiation and how they are used for the design of modern Transition Radiation Detectors (TRD). The discussion will include the various realizations of radiators as well as a discussion of the detection media and aspects of detector construction. With regard to particle identification we assess the different methods for efficient discrimination of different particles and outline the methods for the quantification of this property. Since a number of comprehensive reviews already exist, we predominantly focus on the detectors currently operated at the LHC. To a lesser extent we also cover some other TRDs, which are planned or are currently being operated in balloon or space-borne astro-particle physics experiments.

  5. Semiconductor radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  6. ALICE Transition Radiation Detector

    CERN Multimedia

    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 Pτ tracks in one single TRD stack.

  7. Radiation damages in chemical components of organic scintillator detectors; Danos de radiacao em componentes quimicos de detectores cintiladores organicos

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes Neto, Jose Maria

    2003-07-01

    Samples containing PPO (1%, g/ml), diluted in toluene, they were irradiated in a {sup 60}Co irradiator (6.46 kGy/h) at different doses. The PPO concentration decay bi-exponentially with the dose, generating the degradation products: benzoic acid, benzamide and benzilic alcohol. The liquid scintillator system was not sensitive to the radiation damage until 20 kGy. Otherwise, the pulse height analysis showed that dose among 30 to 40 kGy generate significant loss of quality of the sensor (liquid scintillating) and the light yield was reduced in half with the dose of (34.04 {+-} 0.80) kGy. This value practically was confirmed by the photo peak position analysis that resulted D{sub 1/2} = (31.7 {+-} 1,4) kGy, The transmittance, at 360 nm, of the irradiated solution decreased exponentially. The compartmental model using five compartments (fast decay PPO, slow decay PPO, benzamide, benzoic acid and benzilic alcohol) it was satisfactory to explain the decay of the PPO in its degradation products in function of the dose. The explanation coefficient r{sup 2} = 0.985636 assures that the model was capable to explain 98.6% of the experimental variations. The Target Theory together with the Compartmental Analysis showed that PPO irradiated in toluene solution presents two sensitive molecular diameters both of them larger than the true PPO diameter. >From this analysis it showed that the radiolytic are generated, comparatively, at four toluene molecules diameter far from PPO molecules. For each one PPO-target it was calculated the G parameter (damage/100 eV). For the target expressed by the fast decay the G value was (418.4 {+-} 54.1) damages/100 eV, and for the slow decay target the G value was (54.5 {+-} 8.9) damages/100 eV. The energies involved in the chemical reactions were w (0.239 {+-} 0.031) eV/damage (fast decay) and w = (1 834 {+-} 0.301) eV/damage (slow decay). (author)

  8. Radiation detectors based by polymer materials

    International Nuclear Information System (INIS)

    Scintillation counters make use of the property of certain chemical compounds to emit short light pulses after excitation produced by the passage of charged particles or photons of high energy. These flashes of light are detected by a photomultiplier tube that converts the photons into a voltage pulse. The light emitted from the detector also can be collected, focussed and dispersed by a CCD detector. The study of the evolution of the light emission and of the radiation damage under irradiation is a primary topic in the development of radiation hard polymer based scintillator. Polymer scintillator thin films are used in monitoring radiation beam intensities and simultaneous counting of different radiations. Radiation detectors have characteristics which depend on: the type of radiation, the energy of radiation, and the material of the detector. Three types of polymer thin films were studied: a polyvinyltoluene based scintillator, fluorinated polyimide and PMMA. (authors)

  9. Workshops on radiation imaging detectors

    International Nuclear Information System (INIS)

    This document gathers the transparencies that were presented at the international workshop on radiation imaging detectors. 9 sessions were organized: 1) materials for detectors and detector structure, 2) front end electronics, 3) interconnected technologies, 4) space, fusion applications, 5) the physics of detection, 6) industrial applications, 7) synchrotron radiation, 8) X-ray sources, and 9) medical and other applications

  10. Workshops on radiation imaging detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sochinskii, N.V.; Sun, G.C.; Kostamo, P.; Silenas, A.; Saynatjoki, A.; Grant, J.; Owens, A.; Kozorezov, A.G.; Noschis, E.; Van Eijk, C.; Nagarkar, V.; Sekiya, H.; Pribat, D.; Campbell, M.; Lundgren, J.; Arques, M.; Gabrielli, A.; Padmore, H.; Maiorino, M.; Volpert, M.; Lebrun, F.; Van der Putten, S.; Pickford, A.; Barnsley, R.; Anton, M.E.G.; Mitschke, M.; Gros d' Aillon, E.; Frojdh, C.; Norlin, B.; Marchal, J.; Quattrocchi, M.; Stohr, U.; Bethke, K.; Bronnimann, C.H.; Pouvesle, J.M.; Hoheisel, M.; Clemens, J.C.; Gallin-Martel, M.L.; Bergamaschi, A.; Redondo-Fernandez, I.; Gal, O.; Kwiatowski, K.; Montesi, M.C.; Smith, K

    2005-07-01

    This document gathers the transparencies that were presented at the international workshop on radiation imaging detectors. 9 sessions were organized: 1) materials for detectors and detector structure, 2) front end electronics, 3) interconnected technologies, 4) space, fusion applications, 5) the physics of detection, 6) industrial applications, 7) synchrotron radiation, 8) X-ray sources, and 9) medical and other applications.

  11. Radiation detector with spodumene

    Energy Technology Data Exchange (ETDEWEB)

    D' Amorim, Raquel Aline P.O.; Lima, Hestia Raissa B.R.; Souza, Susana O. [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Fisica; Sasaki, Jose M., E-mail: sasaki@fisica.ufc.b [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisica; Caldas, Linda V.E., E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    In this work, {beta}-spodumene potentiality as a radiation detector was evaluated by making use of thermoluminescence (TL) and thermally stimulated exoelectron emission (TSEE) techniques. The pellets were obtained from the {beta}-spodumene powder mixed with Teflon followed by a sintering process of thermal treatments of 300 deg/30 min and 400 deg/1.5 h. The samples were irradiated in standard gamma radiation beams with doses between 5 Gy and 10 kGy. The TL emission curve showed a prominent peak at 160 deg and in the case of TSEE a prominent peak at 145 Celsius approximately. Initial results show that the material is promising for high-dose dosimetry. (author)

  12. Radiation Hazard Detector

    Science.gov (United States)

    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.

  13. Development of new radiation detectors

    International Nuclear Information System (INIS)

    The works on the development of radiation detectors performed at Waseda University are described. As the fundamental studies on radiation detectors, measurement was made for the Z3 dependence of the power of metal targets to stop alpha particles or C-ions, the Fano factor in rare gas, the peak value of the energy given by fast charged particles to materials and its fluctuation, the W-value and the Fano factor of liquid rare gas, and the LET dependence of the luminescence efficiency of liquid rare gas by radiation. The development of liquid rare gas detectors has been made. The considered detector types were a pulse ionization chamber with grid (liquid Xe), a proportional luminescent counter (liquid Xe), an electromagnetic calorimeter (liquid Ar, liquid Xe), and a photo-ionization detector. The development of silicon detectors is also in progress. The silicon detectors under development are a silicon detector telescope for satellite experiment, a silicon shower detector for balloon experiment, and a micron strip silicon detector for synchrotron radiation or elementary particle experiment. The use of plastic track detectors for cosmic ray observation has been examined. The discrimination of isotopes by using a new plastic CR-39 was able to be done. The detectors for low level alpha and gamma spectroscopy have been investigated. For alpha particles, a pulse ionization chamber with a cylindrical grid has been used. For gamma-ray, a Compton-suppressed Ge(Li) detector has been used. (Kato, T.)

  14. Status of radiation detector and neutron monitor technology

    CERN Document Server

    Kim, Y K; Ha, J H; Han, S H; Hong, S B; Hwang, I K; Lee, W G; Moon, B S; Park, S H; Song, M H

    2002-01-01

    In this report, we describe the current states of the radiation detection technology, detectors for industrial application, and neutron monitors. We also survey the new technologies being applied to this field. The method to detect radiation is the measurement of the observable secondary effect from the interaction between incident radiation and detector material, such as ionization, excitation, fluorescence, and chemical reaction. The radiation detectors can be categorized into gas detectors, scintillation detectors, and semiconductor detectors according to major effects and main applications. This report contains the current status and operational principles of these detectors. The application fields of radiation detectors are industrial measurement system, in-core neutron monitor, medical radiation diagnostic device, nondestructive inspection device, environmental radiation monitoring, cosmic-ray measurement, security system, fundamental science experiment, and radiation measurement standardization. The st...

  15. Simple dynamic electromagnetic radiation detector

    Science.gov (United States)

    Been, J. F.

    1972-01-01

    Detector monitors gamma dose rate at particular position in a radiation facility where a mixed neutron-gamma environment exists, thus determining reactor power level changes. Device also maps gamma intensity profile across a neutron-gamma beam.

  16. Radiation hard cryogenic silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-01-21

    It has been recently observed that heavily irradiated silicon detectors, no longer functional at room temperature, 'resuscitate' when operated at temperatures below 130 K. 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.

  17. Radiation Hardening of Silicon Detectors

    CERN Multimedia

    Leroy, C; Glaser, M

    2002-01-01

    %RD48 %title\\\\ \\\\Silicon detectors will be widely used in experiments at the CERN Large Hadron Collider where high radiation levels will cause significant bulk damage. In addition to increased leakage current and charge collection losses worsening the signal to noise, the induced radiation damage changes the effective doping concentration and represents the limiting factor to long term operation of silicon detectors. The objectives are to develop radiation hard silicon detectors that can operate beyond the limits of the present devices and that ensure guaranteed operation for the whole lifetime of the LHC experimental programme. Radiation induced defect modelling and experimental results show that the silicon radiation hardness depends on the atomic impurities present in the initial monocrystalline material.\\\\ \\\\ Float zone (FZ) silicon materials with addition of oxygen, carbon, nitrogen, germanium and tin were produced as well as epitaxial silicon materials with epilayers up to 200 $\\mu$m thickness. Their im...

  18. 49 CFR 173.310 - Exceptions for radiation detectors.

    Science.gov (United States)

    2010-10-01

    ... for radiation detectors. Radiation detectors, radiation sensors, electron tube devices, or ionization...) Radiation detectors must be single-trip, hermetically sealed, welded metal inside containers that will...

  19. Surprising radiation detectors

    CERN Document Server

    Fleischer, Robert

    2003-01-01

    Radiation doses received by the human body can be measured indirectly and retrospectively by counting the tracks left by particles in ordinary objects like pair of spectacles, glassware, compact disks...This method has been successfully applied to determine neutron radiation doses received 50 years ago on the Hiroshima site. Neutrons themselves do not leave tracks in bulk matter but glass contains atoms of uranium that may fission when hurt by a neutron, the recoil of the fission fragments generates a track that is detectable. The most difficult is to find adequate glass items and to evaluate the radiation shield they benefited at their initial place. The same method has been used to determine the radiation dose due to the pile-up of radon in houses. In that case the tracks left by alpha particles due to the radioactive decay of polonium-210 have been counted on the superficial layer of the window panes. Other materials like polycarbonate plastics have been used to determine the radiation dose due to heavy io...

  20. The study and the realization of radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique

    International Nuclear Information System (INIS)

    The aim of this work was to develop radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique. The influence of surface treatments, contact technology and diamond growth parameters on the diamond detectors characteristics was investigated in order to optimise the detector response to alpha particles. The first part of the study focused on the electrical behaviour of as-deposited diamond surface, showing a p type conduction and its influence on the leakage current of the device. A surface preparation process was established in order to reduce the leakage current of the device by surface dehydrogenation using an oxidising step. Several methods to form and treat electrical contacts were also investigated showing that the collection efficiency of the device decreases after contact annealing. In the second part, we reported the influence of the diamond deposition parameters on the characteristics of the detectors. The increase of the deposition temperature and/or methane concentration was shown to lead η to decrease. In contrast, η was found to increase with the micro-wave power. The evolution of the diamond detector characteristics results from the variation in sp2 phases incorporation and in the crystallography quality of the films. These defects increase the leakage current and reduce the carrier mobility and lifetime. Measurements carried out on detectors with different thicknesses showed that the physical properties varies along the growth direction, improving with the film thickness. Finally, the addition of nitrogen (> 10 ppm) in the gas mixture during diamond deposition was found to strongly reduce the collection efficiency of the detectors. To conclude the study, we fabricated and characterised diamond devices which were used for thermal neutron detection and for the intensity and shape measurement of VUV and soft X-ray pulses. (author)

  1. Flexible composite radiation detector

    Science.gov (United States)

    Cooke, D. Wayne; Bennett, Bryan L.; Muenchausen, Ross E.; Wrobleski, Debra A.; Orler, Edward B.

    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.

  2. Detectors for radiation dosimetry

    International Nuclear Information System (INIS)

    For our purposes in this review, we note the following points: (1) for charged particle detection, these counters can be filled with any noble gas-quenching gas mixture that produces satisfactory electrical signals; (2) neutron counters, in which the neutrons are detected by their interaction with the specific filling of the chamber to yield an ionizing particle, require special gas mixtures containing 3He or BF3, an alternative approach is to coat the inner surface of the cathode with a boron or lithium compound; (3) proportional counters are used if there is any need to discriminate between different types of radiation incident on the chamber by the magnitude of the ionizing energy retained within the sensitive volume of the counter; (4) proportional counters can operate at higher speeds than Geiger counters, typically up to 107 cts/sec versus less than 105/sec for the Geiger counters; and (5) Geiger counters produce very large uniform pulses which can be scaled by very simple electronics, hence, they are often used in survey meters and other portable monitoring instruments

  3. Radiation damage in silicon detectors

    CERN Document Server

    Bruzzi, Mara

    2000-01-01

    This work presents an overview of the most important mechanisms of radiation damage in silicon detectors to be used for high energy experiments in LHC. The changes in the shallow concentration have been studied by Thermally Stimulated Currents (TSC) after proton and neutron irradiation with fluences up to 1015 cm-2 to investigate the role of thermal donors and the donor-removal effect in standard and oxygen enriched silicon with different resistivities. Deep defects in irradiated silicon have been analysed by Deep Level Transient Spectroscopy (DLTS) and Photo Induced Current Transient Spectroscopy (P1CTS) in the same materials. The radiation-induced microscopic disorder has been related with the carrier transport properties of irradiated silicon measured by Hall effect, by capacitance and current vs. voltage characteristics and with charge collection efficiency. The dependence of the irradiated silicon detectors performances on crystal orientation, on incident particle type and on the starting concentration o...

  4. Bismuth tri-iodide radiation detector development

    Science.gov (United States)

    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

  5. Chemical effects of radiation

    International Nuclear Information System (INIS)

    Ionizing radiations initiate chemical changes in materials because of the high energy of their quanta. In water, highly reactive free radicals are produced which can initiate secondary changes of solutes, and in chemical of biological molecules in contact with the water. Free radicals can also be directly produced in irradiated medical products. Their fate can be identified and the molecular basis of radiation inactivation clarified. Methods have now been developed to protect and minimise such radiation damage. (author)

  6. Radiation detectors laboratory; Laboratorio de detectores de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The Radiation detectors laboratory was established with the assistance of the International Atomic Energy Agency which gave this the responsibility to provide its services at National and regional level for Latin America and it is located at the ININ. The more expensive and delicate radiation detectors are those made of semiconductor, so it has been put emphasis in the use and repairing of these detectors type. The supplied services by this laboratory are: selection consultant, detectors installation and handling and associated systems. Installation training, preventive and corrective maintenance of detectors and detection systems calibration. (Author)

  7. Development of CVD diamond radiation detectors

    CERN Document Server

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

    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 presented in terms of collection distance, $d=\\mu E \\tau$, the average distance electron-hole pairs move apart under the influence of an electric field, where $\\mu$ is the sum of carrier mo bilities, $E$ is the applied electric field, and $\\tau$ is the mobility weighted carrier lifetime. Over the last two years the collection distance increased from $\\sim$ 75 $\\mu$m to over 200 $\\mu$ m. With this high quality CVD diamond a series of micro-strip and pixel particle detectors have been constructed. These devices were tested to determine their position resolution and signal to n oise performance. Diamond detectors w...

  8. Hybrid anode for semiconductor radiation detectors

    Science.gov (United States)

    Yang, Ge; Bolotnikov, Aleksey E; Camarda, Guiseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B

    2013-11-19

    The present invention relates to a novel hybrid anode configuration for a radiation detector that effectively reduces the edge effect of surface defects on the internal electric field in compound semiconductor detectors by focusing the internal electric field of the detector and redirecting drifting carriers away from the side surfaces of the semiconductor toward the collection electrode(s).

  9. Radiation experience with the CDF silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Husemann, Ulrich; /Rochester U.

    2005-11-01

    The silicon detectors of the CDF experiment at the Tevatron collider are operated in a harsh radiation environment. The lifetime of the silicon detectors is limited by radiation damage, and beam-related incidents are an additional risk. This article describes the impact of beam-related incidents on detector operation and the effects of radiation damage on electronics noise and the silicon sensors. From measurements of the depletion voltage as a function of the integrated luminosity, estimates of the silicon detector lifetime are derived.

  10. ALICE Transition Radiation Detector (TRD), test beam.

    CERN Multimedia

    2003-01-01

    Electrons and positrons can be discriminated from other charged particles using the emission of transition radiation - X-rays emitted when the particles cross many layers of thin materials. To develop such a Transition Radiation Detector(TRD) for ALICE many detector prototypes were tested in mixed beams of pions and electrons, as in the example shown here.

  11. Development of advanced silicon radiation detectors for harsh radiation environment

    CERN Document Server

    Groenlund, Tanja

    2012-01-01

    This thesis describes the development of advanced silicon radiation detectors and their characterization by simulations, used in the work for searching elementary particles in the European Organization for Nuclear Research, CERN. Silicon particle detectors will face extremely harsh radiation in the proposed upgrade of the Large Hadron Collider, the future high-energy physics experiment Super-LHC. The increase in the maximal fluence and the beam luminosity up to 1016 neq / cm2 and 1035 cm-2s-1 will require detectors with a dramatic improvement in radiation hardness, when such a fluence will be far beyond the operational limits of the present silicon detectors. The main goals of detector development concentrate on minimizing the radiation degradation. This study contributes mainly to the device engineering technology for developing more radiation hard particle detectors with better characteristics. Also the defect engineering technology is discussed. In the nearest region of the beam in Super-LHC, the only dete...

  12. High sensitive radiation detector for radiology dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Valente, M.; Malano, F. [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Molina, W.; Vedelago, J., E-mail: valente@famac.unc.edu.ar [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2014-08-15

    Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, dose rate recorded and incident direction independence as well as linear dose response. This work presents the development and characterization of a novel Fricke gel system, based on modified chemical compositions making possible its application in clinical radiology. Properties of standard Fricke gel dosimeter for high dose levels are used as starting point and suitable chemical modifications are introduced and carefully investigated in order to attain high resolution for low dose ranges, like those corresponding to radiology interventions. The developed Fricke gel radiation dosimeter system achieves the expected typical dose dependency, actually showing linear response in the dose range from 20 up to 4000 mGy. Systematic investigations including several chemical compositions are carried out in order to obtain a good enough dosimeter response for low dose levels. A suitable composition among those studied is selected as a good candidate for low dose level radiation dosimetry consisting on a modified Fricke solution fixed to a gel matrix containing benzoic acid along with sulfuric acid, ferrous sulfate, xylenol orange and ultra-pure reactive grade water. Dosimeter samples are prepared in standard vials for its in phantom irradiation and further characterization by spectrophotometry measuring visible light transmission and absorbance before and after irradiation. Samples are irradiated by typical kV X-ray tubes and calibrated Farmer type ionization chamber is used as reference to measure dose rates inside phantoms in at vials locations. Once sensitive material composition is already optimized, dose-response curves show significant improvement regarding overall sensitivity for low dose levels. According to

  13. A novel compact real time radiation detector.

    Science.gov (United States)

    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 μCi (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

  14. Development of a plasma panel radiation detector

    CERN Document Server

    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.

  15. Development of innovative silicon radiation detectors

    CERN Document Server

    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 ...

  16. Semiconductor High-Energy Radiation Scintillation Detector

    CERN Document Server

    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...

  17. Property of the diamond radiation detector

    International Nuclear Information System (INIS)

    The outstanding properties of diamond, such as radiation hardness, high carrier mobility, high band gap and breakdown field, distinguish it as a good candidate for radiation detectors. In the dosimetry for radiotherapy is permanently searched the detector with high sensitivity, high stability, linear dependence of the response, small size, tissue equivalent material and fast response, for the measuring of the temporal and space variations of the dose. The diamond detector properties as high sensitivity, good spatial and temporal resolution, low Leakage currents, low capacitance, possibility to fabricate robust and compact device and high temperature operation make it possible to use these detectors in many fields from high energy physics till radiation monitoring, from Medical therapy dosimetry till synchrotron radiation measurement. (authors)

  18. Radiation damage in semiconductor detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kraner, H.W.

    1981-12-01

    A survey is presented of the important damage-producing interactions in semiconductor detectors and estimates of defect numbers are made for MeV protons, neutrons and electrons. Damage effects of fast neutrons in germanium gamma ray spectrometers are given in some detail. General effects in silicon detectors are discussed and damage constants and their relationship to leakage current is introduced.

  19. Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Ullaland, O

    2011-01-01

    Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors in 'Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors 3.3.1 Introduction 3.3.2 Time of Flight Measurements 3.3.2.1 Scintillator hodoscopes 3.3.2.2 Parallel plate ToF detectors 3.3.3 Cherenkov Radiation 3.3.3.1 ...

  20. Radiation tests of semiconductor detectors

    OpenAIRE

    Chmill, Valery

    2006-01-01

    This thesis investigates the response of Gallium Arsenide (GaAs) detectors to ionizing irradiation. Detectors based on π-υ junction formed by deep level centers doping. The detectors have been irradiated with 137Cs γ-rays up to 110 kGy, with 6 MeV mean energy neutron up to approximately 6 · 1014 n/cm2, with protons and mixed beam up to 1015 p/cm2. Results are presented for the effects on leakage currents and charge collection efficiencies for minimum ionizing electrons and alpha particles. Th...

  1. Wafer-fused semiconductor radiation detector

    Science.gov (United States)

    Lee, Edwin Y.; James, Ralph B.

    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. CVD diamond detectors for ionizing radiation

    CERN Document Server

    Friedl, M; Bauer, C; Berfermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernegger, H; Pernicka, Manfred; Peitz, A; Pirollo, S; Polesello, P; Pretzl, Klaus P; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Schnetzer, S R; Sciortino, S; Speziali, V; Stelzer, H; Stone, R; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; Ziock, H J; Zöller, M

    1999-01-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2*4 cm/sup 2/ have been grown and refined for better charge collection properties, which are measured with a beta source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5*10/sup 15/ cm/sup -2/ to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (16 refs).

  3. CVD diamond detectors for ionizing radiation

    International Nuclear Information System (INIS)

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2x4 cm2 have been grown and refined for better charge collection properties, which are measured with a β source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5x1015 cm-2 to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (author)

  4. CVD diamond detectors for ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Friedl, M. E-mail: markus.friedl@cern.ch; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hartjes, F.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernegger, H.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Tapper, R.J.; Tesarek, R.; Thomson, G.B.; Trawick, M.; Trischuk, W.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Ziock, H.; Zoeller, M

    1999-10-01

    In future HEP accelerators, such as the LHC (CERN), detectors and electronics in the vertex region of the experiments will suffer from extreme radiation. Thus radiation hardness is required for both detectors and electronics to survive in this harsh environment. CVD diamond, which is investigated by the RD42 Collaboration at CERN, can meet these requirements. Samples of up to 2x4 cm{sup 2} have been grown and refined for better charge collection properties, which are measured with a {beta} source or in a test beam. A large number of diamond samples has been irradiated with hadrons to fluences of up to 5x10{sup 15} cm{sup -2} to study the effects of radiation. Both strip and pixel detectors were prepared in various geometries. Samples with strip metallization have been tested with both slow and fast readout electronics, and the first diamond pixel detector proved fully functional with LHC electronics. (author)

  5. Recent results on the development of radiation-hard diamond detectors

    CERN Document Server

    Conway, J S; Bauer, C; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Dabrowski, W; Da Graca, J; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Jamieson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernicka, Manfred; Peitz, A; Pirollo, S; Plano, R; Polesello, P; Prawer, S; Pretzl, Klaus P; Procario, M; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Russ, J; Schnetzer, S; Sciortino, S; Somalwar, S V; Speziali, V; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R; Thomson, G B; Trawick, M; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; White, C; Ziock, H J; Zöller, M

    1999-01-01

    Charged particle detectors made from chemical vapor deposition (CVD) diamond have radiation hardness greatly exceeding that of silicon- based detectors. The CERN-based RD42 Collaboration has developed and tested CVD diamond microstrip and pixel detectors with an eye to their application in the intense radiation environment near the interaction region of hadron colliders. This paper presents recent results from tests of these detectors. (4 refs).

  6. Semiconductor High-Energy Radiation Scintillation Detector

    OpenAIRE

    Kastalsky, A.; Luryi, S.; 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 d...

  7. CVD diamond detectors of ionising radiation

    International Nuclear Information System (INIS)

    Diamond is a resilient material with excellent physical properties for radiation experiments. As such it is an interesting material for fabrication of high performance solid-state particle detectors operating at room temperature. Its high radiation hardness makes it an ideal material in high radiation environment. High breakdown voltage allows application of high electric field and so speeds up the charge collection. Diamond manufacturing technology (CVD) allows low cost diamond production in large sheets and with higher purity than nature diamonds. There have been already produced CVD diamond detectors with coaxial geometry, planar, micro-strip and pixel detectors. Also at Slovak University of Technology have been already produced first CVD diamond layers. (authors)

  8. Neutron radiation damage studies on silicon detectors

    International Nuclear Information System (INIS)

    Effects of neutron radiation on electrical properties of Si detectors have been studied. At high neutron fluence (Φn ≥ 1012 n/cm2), C-V characteristics of detectors with high resistivities (ρ ≥ 1 kΩ-cm) become frequency dependent. A two-trap level model describing this frequency dependent effect is proposed. Room temperature anneal of neutron damaged (at LN2 temperature) detectors shows three anneal stages, while only two anneal stages were observed in elevated temperature anneal. 19 refs., 14 figs

  9. Cadmium telluride nuclear radiation detectors

    International Nuclear Information System (INIS)

    The characteristics and performance of undoped high resistivity cadmium telluride detectors are compared to chlorine lifted counters. It is shown, in particular, that Undodep CdTe is in fact aluminium doped and that compensation occurs, as an silicon or germanium, by pair and triplet formation between the group III donor and the doubly charged cadmium vacancy acceptor. Furthermore, in chlorine doped samples, the polarization effect results from the unpaired level at Esub(c)-0,6eV

  10. Multiple-mode radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Claus, Liam D.; Derzon, Mark S.; Kay, Randolph R.; Bauer, Todd; Trotter, Douglas Chandler; Henry, Michael David

    2015-08-25

    An apparatus for detecting radiation is provided. In embodiments, at least one sensor medium is provided, of a kind that interacts with radiation to generate photons and/or charge carriers. The apparatus also includes at least one electrode arrangement configured to collect radiation-generated charge from a sensor medium that has been provided. The apparatus also includes at least one photodetector configured to produce an electrical output in response to photons generated by radiation in such a sensor medium, and an electronic circuit configured to produce an output that is jointly responsive to the collected charge and to the photodetector output. At least one such electrode arrangement, at least one such photodetector, and at least one such sensor medium are combined to form an integral unit.

  11. Semiconductor high-energy radiation scintillation detector

    Energy Technology Data Exchange (ETDEWEB)

    Kastalsky, A. [University at Stony Brook, ECE Department and NY State Center for Advanced Sensor Technology, Stony Brook, NY 11794-2350 (United States); Luryi, S. [University at Stony Brook, ECE Department and NY State Center for Advanced Sensor Technology, Stony Brook, NY 11794-2350 (United States)]. E-mail: serge.luryi@stonybrook.edu; Spivak, B. [Department of Physics, University of Washington, Seattle, WA 98195 (United States)

    2006-09-15

    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 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. An important advantage of the proposed detector is its fast response time, about 1 ns, essentially limited only by the recombination time of minority carriers. Notably, the fast response comes without any degradation in brightness. When the scintillator is implemented in a qualified semiconductor material (such as InP or GaAs), the photo-detector and associated circuits can be epitaxially integrated on the scintillator slab and the structure can be stacked-up to achieve virtually any desired absorption capability.

  12. Ionization box type radiation detector

    International Nuclear Information System (INIS)

    An ionization box for monitoring radiation rays, a first amplification circuit of a multi-stage amplification circuit employing a MOS type FET as an initial stage amplification device, a second amplification circuit employing a junction type FET as an initial stage amplification device, a first change-over switch for switching ionization current depending on input signals, a second change-over switch for switching output signals, and a signal level discrimination circuit are constituted integrally. When radiation dose rate is low, the ionization current is inputted to the first amplification circuit and outputted as a radiation ray monitor signal and, when the radiation dose rate is increased to higher than a predetermined value, the ionization current is inputted to the second amplification circuit and outputted as a radiation ray monitor signal. That is, monitoring accuracy is high when the ionization current is low since the MOS type FET of high input impedance is used. If the ionization current is higher than a predetermined value, there is no worry that the detection becomes impossible since the junction type FET having less worry of causing characteristic change due to high radiation dose rate is used. Accordingly, ionization box type monitor at a high monitoring reliability can be obtained. (N.H.)

  13. Radiation hardness characteristics of Si-PIN radiation detectors

    Science.gov (United States)

    Jeong, Manhee; Jo, Woo Jin; Kim, Han Soo; Ha, Jang Ho

    2015-06-01

    The Korea Atomic Energy Research Institute (KAERI) has fabricated Si-PIN radiation detectors with low leakage current, high resistivity (>11 kΩ cm) and low capacitance for high-energy physics and X-ray spectroscopy. Floating-zone (FZ) 6-in. diameter N-type silicon wafers, with crystal orientation and 675 μm thick, were used in the detector fabrication. The active areas are 3 mm×3 mm, 5 mm×5 mm and 10 mm×10 mm. We used a double deep-diffused structure at the edge of the active area for protection from the surface leakage path. We also compared the electrical performance of the Si-PIN detector with anti-reflective coating (ARC). For a detector with an active area of 3 mm×3 mm, the leakage current is about 1.9 nA and 7.4 nA at a 100 V reverse bias voltage, and 4.6 pF and 4.4 pF capacitance for the detector with and without an ARC, respectively. In addition, to compare the energy resolution in terms of radiation hardness, we measured the energy spectra with 57Co and 133Ba before the irradiation. Using developed preamplifiers (KAERI-PA1) that have ultra-low noise and high sensitivity, and a 3 mm×3 mm Si-PIN radiation detector, we obtained energy resolutions with 122 keV of 57Co and 81 keV of 133Ba of 0.221 keV and 0.261 keV, respectively. After 10, 100, 103, 104 and 105 Gy irradiation, we tested the characteristics of the radiation hardness on the Si-PIN radiation detectors in terms of electrical and energy spectra performance changes. The fabricated Si-PIN radiation detectors are working well under high dose irradiation conditions.

  14. Neutron detectors made from chemically vapor deposited semiconductors

    International Nuclear Information System (INIS)

    In this paper, the authors present the results of investigations on the use of semiconductors deposited by chemical vapor deposition (CVD) for the fabrication of neutron detectors. For this purpose, 20 microm thick hydrogenated amorphous silicon (a-Si:H) pin diodes and 100 microm thick polycrystalline diamond resistive detectors were fabricated. The detectors were coupled to a neutron-charged particle converter: a layer of either gadolinium or boron (isotope 10 enriched) deposited by evaporation. They have demonstrated the capability of such neutron detectors to operate at neutron fluxes ranging from 101 to 106 neutrons/cm2.s. The fabrication of large area detectors for neutron counting or cartography through the use of multichannel reading circuits is discussed. The advantages of these detectors include the ability to produce large area detectors at low cost, radiation hardness (∼ 4 Mrad for a-Si:H and ∼ 100 Mrad for diamond), and for diamond, operation at temperatures up to 500 C. These properties enable the use of these devices for neutron detection in harsh environments. Thermal neutron detection efficiency up to 22% and 3% are expected by coupling a-Si:H diodes and diamond detectors to 3 microm thick gadolinium (isotope 157) and 2 microm thick boron layers, respectively

  15. Radiation damage in barium fluoride detector materials

    Energy Technology Data Exchange (ETDEWEB)

    Levey, P.W.; Kierstead, J.A.; Woody, C.L.

    1988-01-01

    To develop radiation hard detectors, particularly for high energy physics studies, radiation damage is being studied in BaF/sub 2/, both undoped and doped with La, Ce, Nd, Eu, Gd and Tm. Some dopants reduce radiation damage. In La doped BaF/sub 2/ they reduce the unwanted long lifetime luminescence which interferes with the short-lived fluorescence used to detect particles. Radiation induced coloring is being studied with facilities for making optical measurements before, during and after irradiation with /sup 60/C0 gamma rays. Doses of 10/sup 6/ rad, or less, create only ionization induced charge transfer effects since lattice atom displacement damage is negligible at these doses. All crystals studied exhibit color center formation, between approximately 200 and 800 nm, during irradiation and color center decay after irradiation. Thus only measurements made during irradiation show the total absorption present in a radiation field. Both undoped and La doped BaF/sub 2/ develop damage at minimum detectable levels in the UV---which is important for particle detectors. For particle detector applications these studies must be extended to high dose irradiations with particles energetic enough to cause lattice atom displacement damage. In principle, the reduction in damage provided by dopants could apply to other applications requiring radiation damage resistant materials.

  16. Heavy ion measurement by chemical detectors

    International Nuclear Information System (INIS)

    In testing the applicability of the threshold system polyvinyl alcohol/methyl orange/chloral hydrate/sodium tetraborate to the quantitative detection of single particles, the chemical detector was irradiated with 4He, 12C, 18O, 22He ions of different LET. Detectors with 4 different borax concentrations (chloral hydrate concentration kept constant) have been irradiated. The dose causing the colour change increased linearly with the borax concentration. For equal borax concentrations this dose increases with increasing LET due to the decreasing G value of the HCl. The fluence ranges measurable with the various detector compositions are given. 4He and 18O ion ranges have been determined. The measured depth dose curves have been corrected because the dose is LET-dependent. The experimentally determined ranges are in good agreement with values calculated for the detector material

  17. Workshop on detectors for synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Arthur L.

    2000-11-22

    Forefront experiments in many scientific areas for which synchrotron sources provide sufficient flux are nonetheless hindered because detectors cannot collect data fast enough, do not cover sufficiently solid angle, or do no have adequate resolution. Overall, the synchrotron facilities, each of which represents collective investments from funding agencies and user institutions ranging from many hundreds of millions to more than a billion dollars, are effectively significantly underutilized. While this chronic and growing problem plagues facilities around the world, it is particularly acute in the United States, where detector research often has to ride on the coat tails of explicitly science-oriented projects. As a first step toward moving out of this predicament, scientists from the U.S. synchrotron facilities held a national workshop in Washington, DC, on October 30-31, 2000. The Workshop on Detectors for Synchrotron Research aimed to create a national ''roadmap'' for development of synchrotron-radiation detectors.

  18. Smart detectors for Monte Carlo radiative transfer

    CERN Document Server

    Baes, Maarten

    2008-01-01

    Many optimization techniques have been invented to reduce the noise that is inherent in Monte Carlo radiative transfer simulations. As the typical detectors used in Monte Carlo simulations do not take into account all the information contained in the impacting photon packages, there is still room to optimize this detection process and the corresponding estimate of the surface brightness distributions. We want to investigate how all the information contained in the distribution of impacting photon packages can be optimally used to decrease the noise in the surface brightness distributions and hence to increase the efficiency of Monte Carlo radiative transfer simulations. We demonstrate that the estimate of the surface brightness distribution in a Monte Carlo radiative transfer simulation is similar to the estimate of the density distribution in an SPH simulation. Based on this similarity, a recipe is constructed for smart detectors that take full advantage of the exact location of the impact of the photon pack...

  19. The Radiation Assessment Detector (RAD) Investigation

    Science.gov (United States)

    Hassler, D. M.; Zeitlin, C.; Wimmer-Schweingruber, R. F.; Böttcher, S.; Martin, C.; Andrews, J.; Böhm, E.; Brinza, D. E.; Bullock, M. A.; Burmeister, S.; Ehresmann, B.; Epperly, M.; Grinspoon, D.; Köhler, J.; Kortmann, O.; Neal, K.; Peterson, J.; Posner, A.; Rafkin, S.; Seimetz, L.; Smith, K. D.; Tyler, Y.; Weigle, G.; Reitz, G.; Cucinotta, F. A.

    2012-09-01

    The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) is an energetic particle detector designed to measure a broad spectrum of energetic particle radiation. It will make the first-ever direct radiation measurements on the surface of Mars, detecting galactic cosmic rays, solar energetic particles, secondary neutrons, and other secondary particles created both in the atmosphere and in the Martian regolith. The radiation environment on Mars, both past and present, may have implications for habitability and the ability to sustain life. Radiation exposure is also a major concern for future human missions. The RAD instrument combines charged- and neutral-particle detection capability over a wide dynamic range in a compact, low-mass, low-power instrument. These capabilities are required in order to measure all the important components of the radiation environment. RAD consists of the RAD Sensor Head (RSH) and the RAD Electronics Box (REB) integrated together in a small, compact volume. The RSH contains a solid-state detector telescope with three silicon PIN diodes for charged particle detection, a thallium doped Cesium Iodide scintillator, plastic scintillators for neutron detection and anti-coincidence shielding, and the front-end electronics. The REB contains three circuit boards, one with a novel mixed-signal ASIC for processing analog signals and an associated control FPGA, another with a second FPGA to communicate with the rover and perform onboard analysis of science data, and a third board with power supplies and power cycling or "sleep"-control electronics. The latter enables autonomous operation, independent of commands from the rover. RAD is a highly capable and highly configurable instrument that paves the way for future compact energetic particle detectors in space.

  20. The Use of Radiation Detectors in Medicine: Radiation Detectors for Functional Imaging (2/3)

    CERN Document Server

    CERN. Geneva

    2009-01-01

    The development of radiation detectors in the field of nuclear and particle physics has had a terrific impact in medical imaging since this latter discipline took off in late ’70 with the invention of the CT scanners. The massive use in High Energy Physics of position sensitive gas detectors, of high Z and high density scintillators coupled to Photomultiplier (PMT) and Position Sensitive Photomultipliers (PSPMT), and of solid state detectors has triggered during the last 30 years a series of novel applications in Medical Imaging with ionizing radiation. The accelerated scientific progression in genetics and molecular biology has finally generated what it is now called Molecular Imaging. This field of research presents additional challenges not only in the technology of radiation detector, but more and more in the ASIC electronics, fast digital readout and parallel software. In this series of three lectures I will try to present how high energy physics and medical imaging development have both benefited by t...

  1. The Use of Radiation Detectors in Medicine: Radiation Detectors for Morphological Imaging (1/3)

    CERN Document Server

    CERN. Geneva

    2009-01-01

    The development of radiation detectors in the field of nuclear and particle physics has had a terrific impact in medical imaging since this latter discipline took off in late ’70 with the invention of the CT scanners. The massive use in High Energy Physics of position sensitive gas detectors, of high Z and high density scintillators coupled to Photomultiplier (PMT) and Position Sensitive Photomultipliers (PSPMT), and of solid state detectors has triggered during the last 30 years a series of novel applications in Medical Imaging with ionizing radiation. The accelerated scientific progression in genetics and molecular biology has finally generated what it is now called Molecular Imaging. This field of research presents additional challenges not only in the technology of radiation detector, but more and more in the ASIC electronics, fast digital readout and parallel software. In this series of three lectures I will try to present how high energy physics and medical imaging development have both benefited by t...

  2. Radiation Experience with the CMS Pixel Detector

    CERN Document Server

    Veszpremi, Viktor

    2015-01-01

    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 read-out 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. Radiation experience with the CMS pixel detector

    Science.gov (United States)

    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.

  4. Nano structural anodes for radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, Joseph V.; Serkiz, Steven M.; McWhorter, Christopher S.; Sexton, Lindsay T.; Retterer, Scott T.

    2015-07-07

    Anodes for proportional radiation counters and a process of making the anodes is provided. The nano-sized anodes when present within an anode array provide: significantly higher detection efficiencies due to the inherently higher electric field, are amenable to miniaturization, have low power requirements, and exhibit a small electromagnetic field signal. The nano-sized anodes with the incorporation of neutron absorbing elements (e.g., .sup.10B) allow the use of neutron detectors that do not use .sup.3He.

  5. Mobile robot prototype detector of gamma radiation

    International Nuclear Information System (INIS)

    In this paper the technological development of a mobile robot prototype detector of gamma radiation is shown. This prototype has been developed for the purpose of algorithms implementation for the applications of terrestrial radiation monitoring of exposed sources, search for missing radioactive sources, identification and delineation of radioactive contamination areas and distribution maps generating of radioactive exposure. Mobile robot detector of radiation is an experimental technology development platform to operate in laboratory environment or flat floor facilities. The prototype integrates a driving section of differential configuration robot on wheels, a support mechanism and rotation of shielded detector, actuator controller cards, acquisition and processing of sensor data, detection algorithms programming and control actuators, data recording (Data Logger) and data transmission in wireless way. The robot in this first phase is remotely operated in wireless way with a range of approximately 150 m line of sight and can extend that range to 300 m or more with the use of signal repeaters. The gamma radiation detection is performed using a Geiger detector shielded. Scan detection is performed at various time sampling periods and diverse positions of discrete or continuous angular orientation on the horizon. The captured data are geographical coordinates of robot GPS (latitude and longitude), orientation angle of shield, counting by sampling time, date, hours, minutes and seconds. The data is saved in a file in the Micro Sd memory on the robot. They are also sent in wireless way by an X Bee card to a remote station that receives for their online monitoring on a laptop through an acquisition program by serial port on Mat Lab. Additionally a voice synthesizing card with a horn, both in the robot, periodically pronounced in Spanish, data length, latitude, orientation angle of shield and detected accounts. (Author)

  6. Semiconductor scintillator detector for gamma radiation

    International Nuclear Information System (INIS)

    Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

  7. X-Ray and Gamma-Ray Radiation Detector

    DEFF Research Database (Denmark)

    2015-01-01

    Disclosed is a semiconductor radiation detector for detecting X-ray and / or gamma-ray radiation. The detector comprises a converter element for converting incident X-ray and gamma-ray photons into electron-hole pairs, at least one cathode, a plurality of detector electrodes arranged with a pitch...

  8. Radiation simulations of the CMS detector

    Science.gov (United States)

    Stoddard, Graham J.

    This thesis presents results of recent radiation simulations for the Compact Muon Solenoid detector at the Large Hadron Collider at CERN performed using the Monte Carlo simulation package FLUKA. High statistics simulations with a fine granularity in the detector were carried out using the Condor batch system at the Fermilab LHC Physics Center. In addition, an existing web tool for accessing and displaying simulation data was upgraded. The FLUKA data and previously generated MARS Monte Carlo data can be plotted using 1-D or 2-D plotting functionalities along R and Z, the transverse distance from the beamline and the distance along the beamline, respectively. Comparisons between the data sets have been carried out; the effect of particle transport thresholds in both packages was explored, comparisons with zero magnetic field in the CMS solenoid and full field are made, a model of non-ionizing energy losses is examined, and sensitive areas of interest within the simulation are identified.

  9. Physics with the ALICE Transition Radiation Detector

    CERN Document Server

    Pachmayer, Yvonne

    2013-01-01

    The ALICE Transition Radiation Detector (TRD) significantly enlarges the scope of physics observables studied in ALICE, because it allows due to its electron identification capability to measure open heavy-flavour production and quarkonium states, which are essential probes to characterize the Quark-Gluon-Plasma created in nucleus-nucleus collisions at LHC. In addition the TRD enables to enhance rare probes due to its trigger contributions. We report on the first results of the electron identification capability of the ALICE Transition Radiation Detector (TRD) in pp collisions at $\\sqrt{s}$ = 7 TeV using a one-dimensional likelihood method on integrated charge measured in each TRD chamber. The analysis of heavy flavour production in pp collisions at $\\sqrt{s}$ = 7 TeV with this particle identification method, which extends the $p_{t}$ range of the existing measurement from $p_{t}$ = 4 GeV/c to 10 GeV/c and reduces the systematic uncertainty due to particle identification, is presented. The performance of the ...

  10. Portable radiation detector and mapping system

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

    A portable radiation detector and mapping system (RADMAPS) has been developed to detect, locate, and plot nuclear radiation intensities on commercially available digital maps and other images. The field unit records gamma-ray spectra or neutron signals together with positions from a global positioning system (GPS) on flash memory cards. The recorded information is then transferred to a laptop computer for spectral data analyses and then georegistered graphically on maps, photographs, etc. RADMAPS integrates several existing technologies to produce a preprogrammable field unit uniquely suited for each survey, as required. The system records spectra from a NaI(Tl) gamma-ray detector or an enriched {sup 6}Li doped glass neutron scintillator. Standard Geographic Information System (GIS) software installed in a lap-top, complete with CD-ROM supporting digitally imaged maps, permits the characterization of nuclear material in the field when the presence of such material is not otherwise documented. This paper gives the results of a typical site survey of the Savannah River site (SRS) using RADMAPS. The ability to provide rapid field data should be of use in treaty verification, safeguards, decontamination, and nuclear weapons dismantlement.

  11. Ruggedization of CdZnTe detectors and detector assemblies for radiation detection applications

    International Nuclear Information System (INIS)

    This paper described improvements in the ruggedization of CdZnTe detectors and detector assemblies for use in radiation detection applications. Research included experimenting with various conductive and underfill adhesive material systems suitable for CZT substrates. A detector design with encapsulation patterning was developed to protect detector surfaces and to control spacing between CZT anode and PCB carrier. Robustness of bare detectors was evaluated through temperature cycling and metallization shear testing. Attachment processes using well-chosen adhesives and PCB carrier materials were optimized to improve reliability of detector assemblies, resulted in Improved Attachment Detector Assembly. These detector assemblies were subjected to aggressive temperature cycling, and varying levels of drop/shock and vibration, in accordance with modified JEDEC, ANSI and FedEx testing standards, to assess their ruggedness. Further enhanced detector assembly ruggedization methods were investigated involving adhesive conformal coating, potting and dam filling on detector assemblies, which resulted in the Enhanced Ruggedization Detector Assembly. Large numbers of CZT detectors and detector assemblies with 5 mm and 15 mm thick, over 200 in total, were tested. Their performance was evaluated by exposure to various radioactive sources using comprehensive predefined detector specifications and testing protocols. Detector assemblies from improved attachment and enhanced ruggedization showed stable performances during the harsh environmental condition tests. In conclusion, significant progress has been made in improving the reliability and enhancing the ruggedness of CZT detector assemblies for radiation detection applications deployed in operational environments. - Highlights: • We developed ruggedization methods to enhance reliability of CZT detector assemblies. • Attachment of CZT radiation detectors was improved through comparative studies. • Bare detector metallization

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

    OpenAIRE

    Barry, Mamadou Yaya

    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, ...

  13. The HERMES dual-radiator RICH detector

    CERN Document Server

    Jackson, H E

    2003-01-01

    The HERMES experiment emphasizes measurements of semi-inclusive deep-inelastic scattering. Most of the hadrons produced lie between 2 and 10 GeV, a region in which it had not previously been feasible to separate pions, kaons, and protons with standard particle identification (PID) techniques. The recent development of new clear, large, homogeneous and hydrophobic silica aerogel material with a low index of refraction offered the means to apply RICH PID techniques to this difficult momentum region. The HERMES instrument uses two radiators, C sub 4 F sub 1 sub 0 , a heavy fluorocarbon gas, and a wall of silica aerogel tiles. A lightweight spherical mirror constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality provides optical focusing on a photon detector consisting of 1934 photomultiplier tubes (PMT) for each detector half. The PMT array is held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet. Ring recon...

  14. Studies of ionizing radiation effects on STAR silicon drift detectors

    International Nuclear Information System (INIS)

    A 63 x 63 mm rectangular silicon drift detector was irradiated using a 60Co source and its performance was studied. The total accumulated dose was 23.5 krad. The detector performance after room temperature annealing was studied. The detector was found to be sufficiently radiation hard for RHIC applications

  15. 18th International Workshop on Radiation Imaging Detectors

    CERN Document Server

    2016-01-01

    The International Workshops on Radiation Imaging Detectors are held yearly and provide an international forum for discussing current research and developments in the area of position sensitive detectors for radiation imaging, including semiconductor detectors, gas and scintillator-based detectors. Topics include processing and characterization of detector materials, hybridization and interconnect technologies, design of counting or integrating electronics, readout and data acquisition systems, and applications in various scientific and industrial fields. The workshop will have plenary sessions with invited and contributed papers presented orally and in poster sessions. The invited talks will be chosen to review recent advances in different areas covered in the workshop.

  16. Real-time self-networking radiation detector apparatus

    Science.gov (United States)

    Kaplan, Edward; Lemley, James; Tsang, Thomas Y.; Milian, Laurence W.

    2007-06-12

    The present invention is for a radiation detector apparatus for detecting radiation sources present in cargo shipments. The invention includes the features of integrating a bubble detector sensitive to neutrons and a GPS system into a miniaturized package that can wirelessly signal the presence of radioactive material in shipping containers. The bubble density would be read out if such indicated a harmful source.

  17. Embedded silicon detector to investigate the natural radiative environment

    International Nuclear Information System (INIS)

    A detector based on a silicon diode was developed to investigate the natural radiative environment. As the detector is embeddable, it has low power consumption and is lightweight and small. The instrument was tested under different neutron beams and used during stratospheric balloon flights. A comparison of the experimental results with Monte Carlo simulation results shows that the embeddable detector is a promising means of investigating the natural radiative environment.

  18. Progress in the Development of Plasma Panel Radiation Detectors

    CERN Document Server

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

    2011-01-01

    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.

  19. Wire chamber radiation detector with discharge control

    International Nuclear Information System (INIS)

    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

  20. Particle and radiation detectors based on diamond

    Energy Technology Data Exchange (ETDEWEB)

    Bergonzo, P.; Tromson, D.; Mer, C.; Guizard, B.; Foulon, F.; Brambilla, A. [LIST/DIMRI/SIAR, CEA/Saclay, Gif-sur-Yvette (France)

    2001-05-16

    CVD diamond is a remarkable material for the fabrication of particle and photon radiation detectors. The improvement of the electronic properties of the material has been under intensive investigations and led to the development of a few applications that are addressing specific industrial needs. In particular, we have used diamond layers for industrial applications where it exhibits attractive characteristics as compared with other materials: e.g., radiation and corrosion hardness for {alpha}-counters or high gamma-meters at high fluxes; high transparency to low energy X-rays for synchrotron beam line monitoring devices, etc. These specific properties can motivate the use of diamond even though the detection properties remain relatively poor. Indeed, one inherent problem with diamond is the presence of defect levels that are altering the detection characteristics. These are observed in all CVD materials but also in very high quality natural diamonds. They result in unstable responses and carrier losses. Also, it has been observed that high sensitivities may result from the progressive filling of deep levels, e.g. pumping effects, with a detrimental effect on the stability and the response time. Also, the polycrystalline nature is somewhat detrimental as it induces significant non-uniformities of the device response with respect to the position of interaction. We have investigated these features by imaging the response of CVD diamond using a micrometer size focused X-ray beam. The comparison with the grain structure showed that it has a strong influence on the field distribution. We present here recent developments studied at CEA in Saclay for the optimisation of the material with respect to the specific requirements of several applications. They include radiation hard counters; X-ray intensity, shape and beam position monitors, solar blind photodetectors, and high dose rate gamma-meters. (orig.)

  1. Design of SJ-10 Space Radiation Detector Prototype

    CERN Document Server

    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.

  2. Radiation hardness of a single crystal CVD diamond detector for MeV energy protons

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yuki, E-mail: y.sato@riken.jp [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Shimaoka, Takehiro; Kaneko, Junichi H. [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Murakami, Hiroyuki [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Isobe, Mitsutaka; Osakabe, Masaki [National Institute for Fusion Science, 322-6, Oroshi-cho Toki-city, Gifu 509-5292 (Japan); Tsubota, Masakatsu [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Ochiai, Kentaro [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chayahara, Akiyoshi; Umezawa, Hitoshi; Shikata, Shinichi [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

    2015-06-01

    We have fabricated a particle detector using single crystal diamond grown by chemical vapor deposition. The irradiation dose dependence of the output pulse height from the diamond detector was measured using 3 MeV protons. The pulse height of the output signals from the diamond detector decreases as the amount of irradiation increases at count rates of 1.6–8.9 kcps because of polarization effects inside the diamond crystal. The polarization effect can be cancelled by applying a reverse bias voltage, which restores the pulse heights. Additionally, the radiation hardness performance for MeV energy protons was compared with that of a silicon surface barrier detector.

  3. Optical Analysis of a Linear-Array Thermal Radiation Detector for Geostationary Earth Radiation Budget Applications

    OpenAIRE

    Sanchez, Maria Cristina

    1998-01-01

    The Thermal Radiation Group, a laboratory in the Department of Mechanical Engineering at Virginia Polytechnic Institute and State University, is currently working to develop a new technology for thermal radiation detectors. The Group is also studying the viability of replacing current Earth Radiation Budget radiometers with this new concept. This next-generation detector consists of a thermopile linear array thermal radiation detector. The principal objective of t...

  4. Radiation physical chemistry effects on organic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, C.H.; Duarte, C.L.; Hamada, M.M. E-mail: mmhamada@net.ipen.br

    2003-06-01

    The radiation damage effect on a liquid scintillating system was evaluated in the PPO and POPOP solutes. Samples containing PPO (1%w/v) and POPOP (0.2%w/v) diluted in toluene were irradiated at different doses, using a {sup 60}Co irradiator at 1.8 Gy/s. The transmittance and the chemical degradation of those solutes were evaluated as a function of dose. The PPO transmittance at 360 nm decayed exponentially with the dose, while the POPOP transmittance at 420 nm decayed linearly. The chemical degradation on the PPO and POPOP was fitted to a bi-exponential mathematical model as a function of dose. The first exponential (fast slope) was interpreted as damage produced by toluene radiolytics whereas the second exponential (slow slope) was interpreted as the damage caused by primary interaction of the {gamma}-radiation with targets, i.e., {gamma} photons that hit PPO and POPOP directly. The w (eV/damage molecule) and G (damaged molecules/100 eV) parameters were estimated in this paper.

  5. A conductive surface coating for Si-CNT radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, Antonio, E-mail: antonio.valentini@ba.infn.it [Dipartimento di Fisica, Università degli Studi di Bari, Via Orabona 4, 70125 Bari (Italy); Valentini, Marco [INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Ditaranto, Nicoletta [Dipartimento di Chimica, Università degli Studi di Bari, Via Amendola 173, 70126 Bari (Italy); Melisi, Domenico [INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Aramo, Carla, E-mail: aramo@na.infn.it [INFN, Sezione di Napoli, Via Cintia 2, 80126 Napoli (Italy); Ambrosio, Antonio [CNR-SPIN U.O.S. di Napoli and Dipartimento di Scienze Fisiche, Università degli Studi di Napoli “Federico II”, Via Cintia 2, 80126 Napoli (Italy); Casamassima, Giuseppe [Dipartimento di Fisica, Università degli Studi di Bari, Via Orabona 4, 70125 Bari (Italy); INFN, Sezione di Bari, Via Orabona 4, 70126 Bari (Italy); Cilmo, Marco [INFN, Sezione di Napoli, and Dipartimento di Scienze Fisiche, Università degli Studi di Napoli “Federico II”, Via Cintia 2, 80126 Napoli (Italy); Fiandrini, Emanuele [INFN, Sezione di Perugia, and Dipartimento di Fisica, Università degli Studi di Perugia, Piazza Università 1, 06100 Perugia (Italy); Grossi, Valentina [INFN, Sezione di L’Aquila, and Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell’Aquila, Via Vetoio 10 Coppito, 67100 L’Aquila (Italy); and others

    2015-08-01

    Silicon–Carbon Nanotube radiation detectors need an electrically conductive coating layer to avoid the nanotube detachment from the silicon substrate and uniformly transmit the electric field to the entire nanotube active surface. Coating material must be transparent to the radiation of interest, and must provide the drain voltage necessary to collect charges generated by incident photons. For this purpose various materials have been tested and proposed in photodetector and photoconverter applications. In this article interface properties and electrical contact behavior of Indium Tin Oxide films on Carbon Nanotubes have been analyzed. Ion Beam Sputtering has been used to grow the transparent conductive layer on the nanotubes. The films were deposited at room temperature with Oxygen/Argon mixture into the sputtering beam, at fixed current and for different beam energies. Optical and electrical analyses have been performed on films. Surface chemical analysis and in depth profiling results obtained by X-ray Photoelectron Spectroscopy of the Indium Tin Oxide layer on nanotubes have been used to obtain the interface composition. Results have been applied in photodetectors realization based on multi wall Carbon Nanotubes on silicon. - Highlights: • ITO was deposited by Ion Beam Sputtering on MWCNT. • ITO on CNT makes an inter-diffusion layer of the order of one hundred nanometers. • Improvements of quantum efficiency of photon detectors based on CNT with ITO.

  6. A conductive surface coating for Si-CNT radiation detectors

    International Nuclear Information System (INIS)

    Silicon–Carbon Nanotube radiation detectors need an electrically conductive coating layer to avoid the nanotube detachment from the silicon substrate and uniformly transmit the electric field to the entire nanotube active surface. Coating material must be transparent to the radiation of interest, and must provide the drain voltage necessary to collect charges generated by incident photons. For this purpose various materials have been tested and proposed in photodetector and photoconverter applications. In this article interface properties and electrical contact behavior of Indium Tin Oxide films on Carbon Nanotubes have been analyzed. Ion Beam Sputtering has been used to grow the transparent conductive layer on the nanotubes. The films were deposited at room temperature with Oxygen/Argon mixture into the sputtering beam, at fixed current and for different beam energies. Optical and electrical analyses have been performed on films. Surface chemical analysis and in depth profiling results obtained by X-ray Photoelectron Spectroscopy of the Indium Tin Oxide layer on nanotubes have been used to obtain the interface composition. Results have been applied in photodetectors realization based on multi wall Carbon Nanotubes on silicon. - Highlights: • ITO was deposited by Ion Beam Sputtering on MWCNT. • ITO on CNT makes an inter-diffusion layer of the order of one hundred nanometers. • Improvements of quantum efficiency of photon detectors based on CNT with ITO

  7. Temperature effects on radiation damage to silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Barberis, E.; Cartiglia, N.; Leslie, J.; Pitzl, D.; Rowe, W.A.; Sadrozinski, H.F.W. (SCIPP, Univ. California, Santa Cruz, CA (United States)); Boissevain, J.G.; Ferguson, P.; Holzscheiter, K.; Kapustinsky, J.S.; Palounek, A.P.T.; Sommer, W.F.; Sondheim, W.E.; Ziock, H.J. (Los Alamos National Lab., NM (United States)); Ellison, J.A.; Fleming, J.K.; Jerger, S.; Joyce, D.; Lietzke, C.; Wimpenny, S.J. (Univ. California, Riverside, CA (United States)); Matthews, J.A.J.; Skinner, D. (Univ. New Mexico, Albuquerque, NM (United States))

    1993-03-01

    Motivated by the large particle fluences anticipated for the SSC and LHC, we are performing a systematic study of radiation damage to silicon microstrip detectors. Here we report radiation effects on detectors cooled to 0deg C (the proposed operating point for a large SSC silicon tracker) including leakage currents and change in depletion voltage. We also present results on the annealing behavior of the radiation damage. Finally, we report results of charge collection measurements of the damaged detectors made with an [sup 241]Am [alpha] source. (orig.).

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

    Science.gov (United States)

    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.

  9. Radiation-chemical antielectrostatic finishing

    International Nuclear Information System (INIS)

    Antielectrostatic finishing of textile fabrics of poly(ethylene terephthalate) was performed by radiation-chemical coating of poly(ethyleneglycol acrylate)s. The achieved modification effect was investigated with regard to its permanence mainly by recording the course of surface resistivity, and as a function of the composition of the modifier (monoacrylate/diacrylate ratio, molar mass), impregnation time and temperature, residual moisture, mass increase, energy dose, and dose rate. Detailed analytical and microscopic investigations evidenced important findings concerning the optimal technology of modification. The results permitted to suggest favorable modification parameters for satisfactory permanence of the effect. (author)

  10. Study on performance of GaN radiation detector

    International Nuclear Information System (INIS)

    Gallium nitride (GaN) as a radiation detector has many advantages, such as wide forbidden band, high resistant radiation and so on. It can be applied in high temperature and high density radiation field environment. The energy spectrum of 241Am α particle was measured by GaN semiconductor detector, and the energy resolution of which is about 30%. At the same time, the energy and detection efficiency calibration of GaN detector was carried out using Si semiconductor detector which was assumed to have 100% detection efficiency. The detection efficiency of GaN detector was up to 80.1%. Finally, current-voltage (I-V) curve was measured using Keithley 2635 electrometer. The background current density is less than 70 nA/cm2 at -15 V reverse bias. (authors)

  11. Solid-state radiation detectors technology and applications

    CERN Document Server

    2015-01-01

    The book discusses the current solid state material used in advance detectors manufacturing and their pros and cons and how one can tailor them using different techniques, to get the maximum performance. The book is application oriented to radiation detectors for medical, X and gamma rays application, and good reference with in-depth discussion of detector's physics as it relates to medical application tailored for engineers and scientists.

  12. On the limit of energy resolution in radiation detectors

    International Nuclear Information System (INIS)

    The limit of energy resolution in various radiation detectors is reviewed from the theoretical view-point. Fano-factors in gaseous, liquid and solid detector media for ionization and for scintillation are discussed and the limit of energy resolution in micro-calorimeters operated at low temperature is also discussed. (author)

  13. Bremstrahlung Detection and Chamber Obstruction Localisation Using Scanning Radiation Detectors

    CERN Document Server

    Naylor, G A; Robinson, D

    2005-01-01

    Radiation monitors consisting of scintillating plastic coupled to photomultipliers are used for diagnostic purposes. By scanning such a detector or a radiation scatterer, two applications are demonstrated: i) Monitoring of vacuum chamber conditioning by monitoring gas Bremstrahlung from residual gas. ii) Localisation of beam interception (beam losses) by longitudinal scanning of a radiation detector. The measurement of gas pressure inside long, small cross section, vacuum vessels is difficult due to the distance between the centre of the vacuum vessel and vacuum gauges (leading to a low vacuum conductance). The narrow beam of gamma Bremstrahlung radiation is intercepted by scanning tungsten blades in the beam line front-end allowing a radiation shower to be detected outside the vacuum vessel proportional to the gas pressure in the corresponding storage ring straight section. A second detector mounted on rails can be moved over a length of 6.5m parallel to the ESRF storage ring so as to localise regions of bea...

  14. Ion radiation damage in plastic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, M

    2006-07-01

    Plastic detectors are widely used for particle identification, micro pore and nano pore technology, neutron, gamma, radon and electron dosimeters. For some applications, plastic detectors have unique advantages among electronic detectors as 4 solid angles for ion identification in nuclear and cosmic ray physics; low-cost for massive use in indoors radon and neutron dosimeters; wide dose-range response for gamma and electron dosimetry; easy to use detectors in active geological faults in prospecting geothermal energy etc. There is a grate diversity of plastic detectors, which further improves their use in a particular application. However, the comparison test between different kinds of plastics can be time consuming, being therefore necessary to have methods for rapidly assessing plastic detectors properties. This invited talk deals in the first part with overview applications in Mexico of plastic detectors mentioned in the first paragraph. In the second part presents a general experimental relationship between the diameter-grow of positive ions tracks in several plastics for light ions, that allow to compare their energy resolution and to predict the track diameter of isotopes beams, as well as to predict the uniformity of micro pores. The formation of Nano pores produced by {sup 238} U ions is also discussed. (Author)

  15. Detection of nuclear radiations; Detectores de radiaciones nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Tanarro Sanz, A.

    1959-07-01

    A summary of the lectures about the ordinary detectors of nuclear radiations given by the author in the Courses of Introduction to Nuclear Engineering held at the JEN up to the date of publication is given. Those lectures are considered to be a necessary introduction to Nuclear Instrumentation and Applied electronics to Nuclear Engineering so it has been intent to underline those characteristics of radiation detectors that must be taken in consideration in choosing or designing the electronic equipment associated to them in order to take advantage of each detector possibilities. (Author) 8 refs.

  16. New detectors of neutron, gamma- and X-radiations

    CERN Document Server

    Lobanov, N S

    2002-01-01

    Paper presents new detectors to record absorbed doses of neutron, gamma- and X-ray radiations within 0-1500 Mrad range. DBF dosimeter is based on dibutyl phthalate. EDS dosimeter is based on epoxy (epoxide) resin, while SD 5-40 detector is based on a mixture of dibutyl phthalate and epoxy resin. Paper describes experimental techniques to calibrate and interprets the measurement results of absorbed doses for all detectors. All three detectors cover 0-30000 Mrad measured does range. The accuracy of measurements is +- 10% independent (practically) of irradiation dose rates within 20-2000 rad/s limits under 20-80 deg C temperature

  17. The radiation environment in the ATLAS inner detector

    CERN Document Server

    Dawson, I

    2000-01-01

    The radiation environment in the inner detector has been simulated using the particle transport program FLUKA with a recent description of the ATLAS experiment. Given in this paper are particle fluences and doses at positions relevant to the three inner detector subsystems; the Pixel, SCT and TRT detectors. In addition, studies are reported on in which (1) information concerning the optimization of the inner detector neutron-moderators is obtained and (2) the impact of including additional vacuum-equipment material is assessed. (19 refs).

  18. Use of HgI2 as gamma radiation detector

    International Nuclear Information System (INIS)

    The Mercuric Iodide (HgI2) has become one of the most promising room temperature semiconductors for the construction of X and gamma radiation detectors. The classical methods of spectroscopy have not demonstrated to achieve optimum results with HgI2 detectors, mainly due to its particular carrier transport properties. Several alternative spectroscopic methods developed in the last ten years are presented and commented, selecting for a complete study one of them: 'The Partial Charge Collection Method'. The transport properties of the carriers generated by the radiation in the detector is specially important for understanding the spectroscopic behaviour of the HgI2 detectors. For a rigorous characterization of this transport, it has been studied a digital technique for the analysis of the electric pulses produced by the radiation. Theoretically, it has been developed a Monte Carlo simulation of the radiation detection and the electronic signal treatment processes with these detectors in the energy range of 60-1300 KeV. These codes are applied to the study of the The Partial Charge Collection Method and its comparison with gaussian methods. Experimentally, this digital techniques is used for the study of the transport properties of thin HgI2 detectors. Special interest is given to the contribution of the slower carriers, the holes, obtaining some consequent of spectroscopic interest. Finally, it is presented the results obtained with the first detectors grown and mounted in CIEMAT with own technology. (author). 129 ref

  19. RD50 Collaboration overview: Development of new radiation hard detectors

    Science.gov (United States)

    Kuehn, S.

    2016-07-01

    Silicon sensors are widely used as tracking detectors in high energy physics experiments. This results in several specific requirements like radiation hardness and granularity. Therefore research for highly performing silicon detectors is required. The RD50 Collaboration is a CERN R&D collaboration dedicated to the development of radiation hard silicon devices for application in high luminosity collider experiments. Extensive research is ongoing in different fields since 2001. The collaboration investigates both defect and material characterization, detector characterization, the development of new structures and full detector systems. The report gives selected results of the collaboration and places an emphasis on the development of new structures, namely 3D devices, CMOS sensors in HV technology and low gain avalanche detectors.

  20. Monolithic active pixel radiation detector with shielding techniques

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, Grzegorz W.

    2016-09-06

    A monolithic active pixel radiation detector including a method of fabricating thereof. The disclosed radiation detector can include a substrate comprising a silicon layer upon which electronics are configured. A plurality of channels can be formed on the silicon layer, wherein the plurality of channels are connected to sources of signals located in a bulk part of the substrate, and wherein the signals flow through electrically conducting vias established in an isolation oxide on the substrate. One or more nested wells can be configured from the substrate, wherein the nested wells assist in collecting charge carriers released in interaction with radiation and wherein the nested wells further separate the electronics from the sensing portion of the detector substrate. The detector can also be configured according to a thick SOA method of fabrication.

  1. Comparison of radiation and chemical risks

    International Nuclear Information System (INIS)

    Injury to living cells is caused by mechanisms which in many cases are similar for radiation and chemicals. It is thus not surprising that radiation and many chemicals can cause similar biological effects, e.g. cancer, fetal injury and hereditary disease. Both radiation and chemicals are always found in our environment. One agent may strengthen or weaken the effect of another, be it radiation in combination with chemicals or one chemical with another. The implications of such synergistic or antagonistic effects are discussed. Intricate mechanisms help the body to defend itself against threats to health from radiation and chemicals, even against cancer risks. In a strategy for health, it might be worth to exploit actively these defense mechanisms, in parallel with decreasing the exposures. On particular interest are the large exposures from commonly known sources such as smoking, sun tanning and high fat contents of food. (author)

  2. Radiation hardness of cryogenic silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-01-11

    We shall review test results which show that silicon detectors can withstand at 130 K temperature a fluence of 2x10{sup 15} cm{sup -2} of 1 MeV 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 irradiated at room temperature using reactor neutrons, and in situ at low temperatures using high-energy protons and lead ions. No substantial difference was observed between samples irradiated at low temperature and those irradiated at room temperature, after beneficial annealing. The design of low-mass modules for low-temperature trackers is discussed briefly, together with the cooling circuits for small and large systems.

  3. Monitoring Radiation Damage in the ATLAS Pixel Detector

    CERN Document Server

    Schorlemmer, André Lukas; Große-Knetter, Jörn; Rembser, Christoph; Di Girolamo, Beniamino

    2014-11-05

    Radiation hardness is one of the most important features of the ATLAS pixel detector in order to ensure a good performance and a long lifetime. Monitoring of radiation damage is crucial in order to assess and predict the expected performance of the detector. Key values for the assessment of radiation damage in silicon, such as the depletion voltage and depletion depth in the sensors, are measured on a regular basis during operations. This thesis summarises the monitoring program that is conducted in order to assess the impact of radiation damage and compares it to model predictions. In addition, the physics performance of the ATLAS detector highly depends on the amount of disabled modules in the ATLAS pixel detector. A worrying amount of module failures was observed during run I. Thus it was decided to recover repairable modules during the long shutdown (LS1) by extracting the pixel detector. The impact of the module repairs and module failures on the detector performance is analysed in this thesis.

  4. Diamond and silicon pixel detectors in high radiation environments

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, Jieh-Wen

    2012-10-15

    Diamond pixel detector is a promising candidate for tracking of collider experiments because of the good radiation tolerance of diamond. The diamond pixel detector must withstand the radiation damage from 10{sup 16} particles per cm{sup 2}, which is the expected total fluence in High Luminosity Large Hadron Collider. The performance of diamond and silicon pixel detectors are evaluated in this research in terms of the signal-to-noise ratio (SNR). Single-crystal diamond pixel detectors with the most recent readout chip ATLAS FE-I4 are produced and characterized. Based on the results of the measurement, the SNR of diamond pixel detector is evaluated as a function of radiation fluence, and compared to that of planar-silicon ones. The deterioration of signal due to radiation damage is formulated using the mean free path of charge carriers in the sensor. The noise from the pixel readout circuit is simulated and calculated with leakage current and input capacitance to the amplifier as important parameters. The measured SNR shows good agreement with the calculated and simulated results, proving that the performance of diamond pixel detectors can exceed the silicon ones if the particle fluence is more than 10{sup 15} particles per cm{sup 2}.

  5. The HERMES dual-radiator ring imaging Cherenkov detector

    CERN Document Server

    Akopov, N; Bailey, K; Bernreuther, S; Bianchi, N; Capitani, G P; Carter, P; Cisbani, E; De Leo, R; De Sanctis, E; De Schepper, D; Dzhordzhadze, V; Filippone, B W; Frullani, S; Garibaldi, F; Hansen, J O; Hommez, B; Iodice, M; Jackson, H E; Jung, P; Kaiser, R; Kanesaka, J; Kowalczyk, R; Lagamba, L; Maas, A; Muccifora, V; Nappi, E; Negodaeva, K; Nowak, Wolf-Dieter; O'Connor, T; O'Neill, T G; Potterveld, D H; Ryckbosch, D; Sakemi, Y; Sato, F; Schwind, A; Shibata, T A; Suetsugu, K; Thomas, E; Tytgat, M; Urciuoli, G M; Van De Kerckhove, K; Van De Vyver, R; Yoneyama, S; Zhang, L F; Zohrabyan, H G

    2002-01-01

    The construction and use of a dual radiator Ring Imaging Cherenkov (RICH) detector is described. This instrument was developed for the HERMES experiment at DESY which emphasises measurements of semi-inclusive deep-inelastic scattering. It provides particle identification for pions, kaons, and protons in the momentum range from 2 to 15 GeV, which is essential to these studies. The instrument uses two radiators, C sub 4 F sub 1 sub 0 , a heavy fluorocarbon gas, and a wall of silica aerogel tiles. The use of aerogel in a RICH detector has only recently become possible with the development of clear, large, homogeneous and hydrophobic aerogel. A lightweight mirror was constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality. The photon detector consists of 1934 photomultiplier tubes (PMT) for each detector half, held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet.

  6. The HERMES dual-radiator ring imaging Cerenkov detector

    CERN Document Server

    Akopov, N Z; Bailey, K; Bernreuther, S; Bianchi, N; Capitani, G P; Carter, P; Cisbani, E; De Leo, R; De Sanctis, E; De Schepper, D; Dzhordzhadze, V; Filippone, B W; Frullani, S; Garibaldi, F; Hansen, J O; Hommez, B; Iodice, M; Jackson, H E; Jung, P; Kaiser, R; Kanesaka, J; Kowalczyk, R; Lagamba, L; Maas, A; Muccifora, V; Nappi, E; Negodaeva, K; Nowak, Wolf-Dieter; O'Connor, T; O'Neill, T G; Potterveld, D H; Ryckbosch, D; Sakemi, Y; Sato, F; Schwind, A; Shibata, T A; Suetsugu, K; Thomas, E; Tytgat, M; Urciuoli, G M; Van de Kerckhove, K; Van de Vyver, R; Yoneyama, S; Zohrabyan, H G; Zhang, L F

    2002-01-01

    The construction and use of a dual radiator Ring Imaging Cerenkov(RICH) detector is described. This instrument was developed for the HERMES experiment at DESY which emphasizes measurements of semi-inclusive deep-inelastic scattering. It provides particle identification for pions, kaons, and protons in the momentum range from 2 to 15 GeV, which is essential to these studies. The instrument uses two radiators, C4F10, a heavy fluorocarbon gas, and a wall of silica aerogel tiles. The use of aerogel in a RICH detector has only recently become possible with the development of clear, large homogeneous and hydrophobic aerogel. A lightweight mirror was constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality. The photon detector consists of 1934 photomultiplier tubes for each detector half, held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet.

  7. The HERMES dual-radiator ring imaging Cherenkov detector

    International Nuclear Information System (INIS)

    The construction and use of a dual radiator Ring Imaging Cherenkov (RICH) detector is described. This instrument was developed for the HERMES experiment at DESY which emphasises measurements of semi-inclusive deep-inelastic scattering. It provides particle identification for pions, kaons, and protons in the momentum range from 2 to 15 GeV, which is essential to these studies. The instrument uses two radiators, C4F10, a heavy fluorocarbon gas, and a wall of silica aerogel tiles. The use of aerogel in a RICH detector has only recently become possible with the development of clear, large, homogeneous and hydrophobic aerogel. A lightweight mirror was constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality. The photon detector consists of 1934 photomultiplier tubes (PMT) for each detector half, held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet

  8. The photon detector of the HERMES dual-radiator RICH

    Science.gov (United States)

    Aschenauer, E. C.; Van der Kerckhove, K.

    1999-08-01

    To provide hadron identification over the full kinematic range (2-20GeV) of the HERMES experiment, the gas threshold Cherenkov counters were replaced by a dual-radiator ring-imaging Cherenkov detectors incorporating for the first time aerogel (SiO2) and C4F10 gas as radiator materials. This combination of radiators requires a photon detector that is sensitive over wavelengths from ultraviolet to 700nm. Commercially available `3/4 in.' photo-multipliers were chosen to form an array of 2000 for each of two photon-detectors. Exhaustive calibration and sorting of the phototubes prior to installation resulted in very low noise hit rates in the LeCroy PCOS4 readout system, with a uniform effective threshold of 0.1 photo-electrons.

  9. Radiation hardness of three-dimensional polycrystalline diamond detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lagomarsino, Stefano, E-mail: lagomarsino@fi.infn.it; Sciortino, Silvio [National Institute of Nuclear Physics (INFN), Via B. Rossi, 1-3, 50019 Sesto Fiorentino (Italy); Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Bellini, Marco [European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Istituto Nazionale di Ottica (INO-CNR), Largo Enrico Fermi 6, 50125 Firenze (Italy); Corsi, Chiara [Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Cindro, Vladimir [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Kanxheri, Keida; Servoli, Leonello [National Institute of Nuclear Physics (INFN), Via A. Pascoli, 06123 Perugia (Italy); Department of Physics, University of Perugia, Via A. Pascoli, 06123 Perugia (Italy); Morozzi, Arianna [Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Passeri, Daniele [National Institute of Nuclear Physics (INFN), Via A. Pascoli, 06123 Perugia (Italy); Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Schmidt, Christian J. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt (Germany)

    2015-05-11

    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 ×10{sup 16 }cm{sup −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.

  10. Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, Harris; Kass, Richard; Gan, K. K.

    2014-01-23

    With the LHC upgrades in 2013, and further LHC upgrades scheduled in 2018, most LHC experiments are planning for detector upgrades which require more radiation hard technologies than presently available. At present all LHC experiments now have some form of diamond detector. As a result Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of all LHC experiments. Moreover CVD diamond is now being discussed as an alternative sensor material for tracking very close to the interaction region of the HL-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications. Our accomplishments include: • Developed a two U.S.companies to produce electronic grade diamond, • Worked with companies and acquired large area diamond pieces, • Performed radiation hardness tests using various proton energies: 70 MeV (Cyric, Japan), 800 MeV (Los Alamos), and 24 GeV (CERN).

  11. Radiation damage measurements on CZT drift strip detectors

    DEFF Research Database (Denmark)

    Kuvvetli, Irfan; Budtz-Jørgensen, Carl; Korsbech, Uffe C C;

    2003-01-01

    At DSRI, in collaboration with the cyclotron facility at Copenhagen University Hospital, we have performed a study of radiation effects exposing a 2.7 mm thick CZT drift strip detector to 30 MeV protons. The detector characteristics were evaluated after exposure to a number of fluences in the range....... A numerical model that emulates the physical processes of the charge transport in the CZT detector was used to derive the charge trapping parameter, mutau(e), (the product of charge mobility and trapping time) as a function of fluence. The analysis showed that the electron trapping increased proportionately...

  12. R&D for Better Nuclear Security: Radiation Detector Materials

    Energy Technology Data Exchange (ETDEWEB)

    Kammeraad, J E

    2009-04-02

    I am going to talk about the need for better materials for radiation detectors. I believe that government investment in this area can enable transformational technology change that could impact domestic nuclear security and also national nuclear security in some very positive and powerful ways. I'm not going to give you a lecture on how radiation detectors work, but I am going to tell you a bit about today's off-the-shelf technology and why it is not sufficient, what we need, and what security benefit you could get from improvements. I think we're at a critical point in time for some very impactful investments. In particular I'm going to focus on the use of gamma-ray radiation detectors at ports of entry. Not long before DHS was formed, Congress decreed that counter measures against the delivery of radiological and nuclear threats would be put in place at US ports of entry, under the authority of US Customs (later Customs and Border Protection in DHS). This included the screening of all cars and trucks passing through a port of entry. Existing off-the-shelf radiation detectors had to be selected for this purpose. Plans were made to make the most of the available technologies, but there are some inherent limitations of these detectors, plus the operational setting can bring out other limitations.

  13. The Gamma-Ray Response of Silicon Carbide Radiation Detectors

    International Nuclear Information System (INIS)

    Silicon Carbide (SiC) radiation detectors are being developed for charged-particle, neutron, and gamma-ray detection. SiC is a wide band gap semiconductor that offers several advantages for use as a solid-state radiation detector. Among these are the ability of SiC devices to operate at elevated temperatures and their improved resistance to radiation compared to other semiconductors. SiC charged-particle detectors have been shown to have good energy resolution for alpha particles. Furthermore, pulse heights and full-widths at half-maximum were found to be completely unperturbed by changes in temperature up to 89 C. In subsequent measurements, SiC neutron detectors based on detection of neutron-induced tritons from a juxtaposed 6LiF foil were shown to have a highly linear response to thermal neutron flux in the range from 1.76 x 104 to 3.59 x 1010 cm-2/s in National Institute of Standards and Technology neutron fields. An important attribute of SiC radiation detectors is their ability to operate in and monitor intense gamma-ray fields while in pulse-mode operation

  14. Effect of temperature on silicon PIN photodiode radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Soo; Jeong, Man Hee; Kim, Young Soo; HA, Jang Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seong Yeon [Yonsei University, Wonju (Korea, Republic of)

    2014-03-15

    One of the noise sources of a semiconductor radiation detector is thermal noise, which degrades the performance, such as the energy resolution and unexpected random pulse signals. In this study, PIN photodiode radiation detectors, with different active areas were designed and fabricated for an experimental comparison of the energy resolutions for different temperatures and capacitances by using a Ba-133 calibration gamma-ray source. The experimental temperature was approximately in the range from -7 to 24 .deg. C and was controlled by using a peltier device. The design considerations and the electrical characteristics, such as the I-V and the C-V characteristics, are also addressed.

  15. Organic semiconductors as real-time radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, T., E-mail: tsuzuki@hep.sc.niigata-u.ac.jp [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Miyata, H., E-mail: miyata@hep.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan); Katsumata, M. [Department of Physics, Niigata University, Niigata 950-2181 (Japan); Nakano, S.; Matsuda, K. [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Tamura, M. [Carlit Holdings Co., Ltd., Tokyo 104-0031 (Japan)

    2014-11-01

    In this study, the possibility of using π-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 α- and β-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.

  16. [Effects of ionizing radiation on scintillators and other particle detectors

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    Seco, Joao; Clasie, Ben; Partridge, Mike

    2014-10-01

    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

  18. The pin detector - a simple, robust, cheap and effective nuclear radiation detector

    International Nuclear Information System (INIS)

    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 the most convenient. The structures are robust and call for no precision alignments so keeping costs down. Performance of the devices in respect of sensitivity and pulse height resolution is comparable to that of conventional wire counters. (orig.)

  19. Time Dependent DD Neutrons Measurement Using a Single Crystal Chemical Vapor Deposition Diamond Detector on EAST

    Science.gov (United States)

    Du, Tengfei; Peng, Xingyu; Chen, Zhongjing; Hu, Zhimeng; Ge, Lijian; Hu, Liqun; Zhong, Guoqiang; Pu, Neng; Chen, Jinxiang; Fan, Tieshuan

    2016-09-01

    A single crystal chemical vapor deposition (scCVD) diamond detector has been successfully employed for neutron measurements in the EAST (Experimental Advanced Superconducting Tokamak) plasmas. The scCVD diamond detector coated with a 5 μm 6LiF (95% 6Li enriched) layer was placed inside a polyethylene moderator to enhance the detection efficiency. The time-dependent neutron emission from deuteron plasmas during neutral beam injection (NBI) heating was obtained. The measured results are compared with that of fission chamber detectors, which always act as standard neutron flux monitors. The scCVD diamond detector exhibits good reliability, stability and the capability to withstand harsh radiation environments despite its low detection efficiency due to the small active volume. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB106004 and 2012GB101003) and National Natural Science Foundation of China (No. 91226102)

  20. Radiation, chemicals, and occupational health research

    International Nuclear Information System (INIS)

    Radiation protection and its interplay with physical research programs are described. Differences and similarities between problems in health protection for chemicals and for radiation are discussed. The importance of dosimetry in radiation work and its relevance to chemicals are cited. A collaborative program between physical and biological scientists on the toxicity of metals is briefly described. It serves as an example of new research directed toward the development of fundamental concepts and principles as a basis for understanding and controlling occupational and population exposures to chemicals. 12 references, 4 figures

  1. Successful beam tests for ALICE Transition Radiation Detector

    CERN Multimedia

    2002-01-01

    Another round of beam tests of prototypes for the Transition Radiation Detector (TRD) for ALICE has been completed and there are already some good results. Mass production of the components of the detector will start early next year.   Top view of the setup for the Transition Radiation Detector prototype tests at CERN.On the left, can be seen the full-scale TRD prototype together with four smaller versions. These are busy days for the TRD (Transition Radiation Detector) team of ALICE. Twenty people - mainly from Germany, but also from Russia and Japan - were working hard during the beam tests this autumn at CERN to assess the performance of their detector prototypes. Analysis of the data shows that the TRD can achieve the desired physics goal even for the highest conceivable multiplicities in lead-lead collisions at the LHC. In its final configuration in the ALICE experiment, the TRD will greatly help in identifying high-momentum electrons, which are 'needles in a haystack' that consists mostly of...

  2. Application of solid state nuclear track detectors in radiation protection

    International Nuclear Information System (INIS)

    This article reviews the current status of the application of nuclear track detectors with emphasis on recent developments in the field of radiation protection. Track etch detectors have been used for the measurements of low level radiation in the environment, fast neutron and radon daughter inhalation dose. Recent developments in the field of dosimetry seem to be promising. In fast neutron dosimetry, track etch detectors can be used without inclusion of fissile materials by using the electrochemical etching technique. These detectors can provide important information in the energy range upto 250 keV. Survey of this range of energy with TLD is difficult because they are extremely energy dependent and over-respond to low energy neutrons. Measurement of radon using track detectors can help to lower the cost of the radon dosimeters. Certain detectors are sensitive to alpha particles from radon and their progeny. Higher sensitivity permits their use in a passive type of personnel dosimeter, which does not require the troublesome aspects of air sampling for the collection of radon daughter samples. (author), 38 refs., 8 tabs., 12 figs

  3. Experimental investigation of the radiation shielding of a MCP detector in the radiation environment near Europa

    Science.gov (United States)

    Tulej, Marek; Wurz, Peter; Meyer, Stefan; Lasi, Davide; Lüthi, Matthias; Galli, André; Piazza, Daniele; Desorgher, Laurent; Hajdas, Wojciech; Reggiani, Davide; Karlsson, Stefan; Kalla, Leif

    2016-04-01

    The Neutral Ion Mass spectrometer (NIM) is one of the six instruments in the Particle Environmental Package (PEP) designed for the JUICE mission of ESA to the Jupiter system. NIM will conduct detailed measurements of chemical composition of Jovian moon exospheres and is equipped with a sensitive MCP ion detector. To maintain high sensitivity of the NIM instrument, background signals arising from the presence of a large background of penetrating radiation (mostly high-energy electrons and protons) in Jupiter's magnetosphere have to be minimised. We investigate the performance of a layered-Z radiation shield, an Al-Ta-Al sandwich, as a potential shielding against high-energy electrons. The experimental investigations were performed at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute (PSI), Villigen, Switzerland. The facility delivers a particle beam containing e,  and  with an adjustable momentum ranging from 17.5 to 345 MeV/c. The measurements of the induced radiation background generated during the interaction of primary particles with Al-Ta-Al sandwich were conducted by beam diagnostic methods and a MCP detector. Diagnostic methods provided for the characterisation of the beam parameters (beam geometry, flux and intensity) and identification of individual particles in the primary beam and in the flux of secondary particles. The MCP detector measurements provided information on the effects of radiation and the results of these measurements define the performance of the shielding material in reducing the background arising from penetrating radiation. In parallel, we performed modelling studies using GEANT 4 and GRASS methods to identify products of the interaction and predict their fluxes and particle rates at the MCP detector. Combination of the experiment and modelling studies yields detailed characterisation of the radiation effects produced by the interaction of the incident e- in the

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

    CERN Document Server

    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.

  5. Proximity focusing RICH detector based on multilayer silica aerogel radiator

    CERN Document Server

    De Leo, R; Bellunato, T; Calvi, M; Cisbani, E; Cusanno, F; Garibaldi, F; Lagamba, L; Marra, M; Marrone, S; Matteuzzi, C; Musico, P; Nappi, E; Perego, D L; Torrioli, S; Vilardi, I

    2010-01-01

    The performance of a proximity focusing Ring Imaging Cherenkov detector equipped with a radiator of silica aerogel is presented. The aerogel tile used is a monolith with variable index of refraction. Cherenkov photons are detected with high granularity by eight Hamamatsu H9500 flat panel multi anode phototubes.

  6. Evaluation of a digital optical ionizing radiation particle track detector

    International Nuclear Information System (INIS)

    An ionizing radiation particle track detector is outlined which can, in principle, determine the three-dimensional spatial distribution of all the secondary electrons produced by the passage of ionizing radiation through a low-pressure (0.1 to 10 kPa) gas. The electrons in the particle track are excited by the presence of a high-frequency AC electric field, and two digital cameras image the optical radiation produced in electronic excitation collisions of the surroundings gas by the electrons. The specific requirements of the detector for neutron dosimetry and microdosimetry are outlined (i.e., operating conditions of the digital cameras, high voltage fields, gas mixtures, etc.) along with an estimate of the resolution and sensitivity achievable with this technique. The proposed detector is shown to compare favorable with other methods for obtaining the details of the track structure, particularly in the quality of the information obtainable about the particle track and the comparative simplicity and adaptability of the detector for measuring the secondary electron track structure for many forms of ionizing radiation over a wide range of energies

  7. Spectra of radioactive nuclides radiation, measured with semiconductor detectors. 2

    International Nuclear Information System (INIS)

    The second part of the atlas 'Radiation spectra of radionuclides measured with semiconductor detectors' is presented including 259 spectra of 126 alpha, beta, gamma, and X ray emitters. Some spectra of the first part of the atlas are given at another scale and sometimes for other energy ranges. The total number of investigated radionuclides amounts to 261 of which 69 are new ones

  8. A radiation detector design mitigating problems related to sawed edges

    International Nuclear Information System (INIS)

    In pixelated silicon radiation detectors that are utilized for the detection of UV, visible, and in particular Near Infra-Red (NIR) light it is desirable to utilize a relatively thick fully depleted Back-Side Illuminated (BSI) detector design providing 100% Fill Factor (FF), low Cross-Talk (CT), and high Quantum Efficiency (QE). The optimal thickness of such detectors is typically less than 300μm and above 40μm and thus it is more or less mandatory to thin the detector wafer from the backside after the front side of the detector has been processed and before a conductive layer is formed on the backside. A TAIKO thinning process is optimal for such a thickness range since neither a support substrate on the front side nor lithographic steps on the backside are required. The conductive backside layer should, however, be homogenous throughout the wafer and it should be biased from the front side of the detector. In order to provide good QE for blue and UV light the conductive backside layer should be of opposite doping type than the substrate. The problem with a homogeneous backside layer being of opposite doping type than the substrate is that a lot of leakage current is typically generated at the sawed chip edges, which may increase the dark noise and the power consumption. These problems are substantially mitigated with a proposed detector edge arrangement which 2D simulation results are presented in this paper

  9. Study of radiation detectors response in standard X, gamma and beta radiation standard beams

    International Nuclear Information System (INIS)

    The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams (37Cs and 60Co), and some of them were tested in beta radiation (90Sr+9'0Y e 204Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author)

  10. Radiation effects on II-VI compound-based detectors

    CERN Document Server

    Cavallini, A; Dusi, W; Auricchio, N; Chirco, P; Zanarini, M; Siffert, P; Fougeres, P

    2002-01-01

    The performance of room temperature CdTe and CdZnTe detectors exposed to a radiation source can be strongly altered by the interaction of the ionizing particles and the material. Up to now, few experimental data are available on the response of II-VI compound detectors to different types of radiation sources. We have carried out a thorough investigation on the effects of gamma-rays, neutrons and electron irradiation both on CdTe : Cl and Cd sub 0 sub . sub 9 Zn sub 0 sub . sub 1 Te detectors. We have studied the detector response after radiation exposure by means of dark current measurements and of quantitative spectroscopic analyses at low and medium energies. The deep traps present in the material have been characterized by means of PICTS (photo-induced current transient spectroscopy) analyses, which allow to determine the trap apparent activation energy and capture cross-section. The evolution of the trap parameters with increasing irradiation doses has been monitored for all the different types of radiati...

  11. Characterization of a radiation detector for aircraft measurements

    Energy Technology Data Exchange (ETDEWEB)

    Holanda M, L. de; Federico, C. A.; Caldas, L. V. E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares, Av. Lineu Prestes 2242, Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil)

    2014-08-15

    Air crews, as pilots and flight attendants, are subjected to cosmic ray doses which can be higher than the average doses on workers from the nuclear industry. The diversity of particles of high energies present in the radiation field on board of air crafts turns the determination of the incident dose difficult, and requires special care regarding dosimetric systems to be used in this kind of radiation field. The Brazilian Air Force, through its Institute for Advanced Studies (Instituto de Estudos Avancados, IEAv/DCTA) in conjunction with the Institute of Energetic and Nuclear Research (Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP) are working on this subject since 2008. A prototype of a radiation detector for aircraft measurements was previously built and tested in flight and laboratory conditions. The detector is able of measuring a quantity known as absorbed dose (using passive dosimeters), which will subsequently be correlated to the ambient dose equivalent and the effective dose received by air crews. In this context, a theoretical approach through Monte Carlo simulations with the computational codes MCNP5 and MCNPX was used to model and characterize the detector response at such experimental conditions. This work presents the preliminary results of the computational modeling, with special emphasis on the comparison between the absorbed doses measured and simulated, and its relationship with the ambient dose equivalent and the effective dose for this detector. (author)

  12. The effects of ultraviolet radiation on some plastic detectors

    International Nuclear Information System (INIS)

    Exposure to ultraviolet (U.V.) radiation could lead to the development of phototoxicity, photoallergy and enhancement of photocarcinogenesis (IRPA 1979). For the measurement of the dose of ultraviolet radiation harmful to human bodies, it is desirable to use a detector with a response curve similar to the human action spectra for erythema and for ultraviolet radiation. It is not easy to obtain a detector which satisfies the requirement unless a very complicated setup of spectrometer with suitable photodetectors is employed. For the purpose of measuring the personal dose, a passive type of detector is preferred. Davis et al (1976) has developed a detector using polysulphone for this purpose. The response curve shows a broad peak extending from 260 to 325 nm. Other detectors (spectrosonics, Partridge and Barton 1978, Fanslow et al 1983), which were developed for similar purposes, have a sharp peak around 280 to 320 nm. These response curves are not very good approximations to the human action spectrum which has a sharp cut-off at around 300 nm. They tend to overestimate the contribution on the long wavelength region (300-320 nm) of UV-B. The integrated response in the UV-B region could be twice the total area of the human action spectrum in the same region of wavelength. The irradiance of these long wavelengths is at least ten times that of the short wavelengths (less than 300 nm) in the solar spectrum. A search for materials with a better approximation than the three types of detectors mentioned above would be useful in the development of a more accurate dosimeter. In this paper, we will report our preliminary results on a new type of plastic material

  13. Response of radiation detectors in electron accelerator environment

    International Nuclear Information System (INIS)

    Full text: Due to the complex nature of radiation field present in high-energy electron accelerators and in associated systems, radiation measurements and interpretation of the results become a difficult task. In the present paper response of radiation instruments due to pulsed radiation of different duty cycle, radio frequency (RF) and low frequency (LF) interference from radio frequency generators (eg. magnetron) and associated systems are studied and the results are presented. The results show that gas filled detectors operated in the multiplicative region (eg. GM tube) severely underestimate the radiation field at very low duty cycles. The response is found to improve as the duty cycle is increased. RF, LF and magnetic field interference also is studied and the results are discussed

  14. Development of Superconducting Tunnel Junction as an Imaging Radiation Detector

    Science.gov (United States)

    Yamasaki, N. Y.; Rokutanda, E.; Kikuchi, K.; Kushino, A.; Ohashi, T.; Kurakado, M.

    Superconducting tunnel junctions (STJs) as X-ray detectors have been developed mainly aiming at high resolution spectrometers. We archived an energy resolution of 106 eV at 5.9 keV (FWHM) using an STJ developed at Nippon Steel Corporation with a cooled (~ 100K) FET. Furthermore, series-connected STJs as an imaging radiation detector are developed. Both the pulse hight and the rise time of signals from 241Am α-particles irradiated on a series-connected STJ give a good position sensitivity, indicating the intrinsic position resolution less than 0.5 mm

  15. The study and the realization of radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique; Etude et realisation de detecteurs de rayonnements a base de films de diamant polycristallin elabores par depot chimique en phase vapeur assiste par plasma micro-onde

    Energy Technology Data Exchange (ETDEWEB)

    Jany, Ch

    1998-10-29

    The aim of this work was to develop radiation detectors made from polycrystalline diamond films grown by microwave plasma enhanced chemical vapour deposition technique. The influence of surface treatments, contact technology and diamond growth parameters on the diamond detectors characteristics was investigated in order to optimise the detector response to alpha particles. The first part of the study focused on the electrical behaviour of as-deposited diamond surface, showing a p type conduction and its influence on the leakage current of the device. A surface preparation process was established in order to reduce the leakage current of the device by surface dehydrogenation using an oxidising step. Several methods to form and treat electrical contacts were also investigated showing that the collection efficiency of the device decreases after contact annealing. In the second part, we reported the influence of the diamond deposition parameters on the characteristics of the detectors. The increase of the deposition temperature and/or methane concentration was shown to lead {eta} to decrease. In contrast, {eta} was found to increase with the micro-wave power. The evolution of the diamond detector characteristics results from the variation in sp{sup 2} phases incorporation and in the crystallography quality of the films. These defects increase the leakage current and reduce the carrier mobility and lifetime. Measurements carried out on detectors with different thicknesses showed that the physical properties varies along the growth direction, improving with the film thickness. Finally, the addition of nitrogen (> 10 ppm) in the gas mixture during diamond deposition was found to strongly reduce the collection efficiency of the detectors. To conclude the study, we fabricated and characterised diamond devices which were used for thermal neutron detection and for the intensity and shape measurement of VUV and soft X-ray pulses. (author)

  16. Proceedings of the workshop on radiation detector and its application

    International Nuclear Information System (INIS)

    This workshop was held from January 23 to 25, 1996 at National Laboratory for High Energy Physics. At the workshop, lectures were given on the development of the single ion detector using MCP in heavy ion microbeam device, the response of MCP to single heavy ion, the response of a superheated liquid drop type detector to low LET radiation, the response characteristics of a CR-39 flight track detector to hydrogen isotopes, the analysis of small nuclear flight tracks on CR-39 with an interatomic force microscope, charge-sensible amplifiers, the signal-processing circuit for position detection, time and depth-resolved measurement of ion tracks in condensed matter, the response of a thin Si detector to electrons, the method of expressing gas-amplifying rate curves in proportional count gas for low temperature, the characteristics of self annihilating streamer by ultraviolet laser, the development of slow positron beam using radioisotopes, the development of a tunnel junction type x-ray detector, the development of the pattern-analyzing system for PIXE spectra, the characteristics of NE213-CaF2 bond type neutron detector and many others. In this report, the gists of these papers are collected. (K.I.)

  17. Ionizing radiation solid detectors on the base of amorphous arsenic chalcogenides

    International Nuclear Information System (INIS)

    The possibility to use radiation-sensitive elements of solid chalcogenide glass-like semiconductors (CGS) - special class of oxygen-free amorphous substances, which are alloys of groups 3, 4 and 5 elements with chalcogens (S, Se, Te), was analyzed. The materials feature lower temperatures of radiation information erasure (440-470 K) than oxide glasses. Radiation-induced electron-defect processes lay at physical basis of operation of CGS-based solid detectors. The processes consist in violation of atom normal coordination at the expense of chemical bond rupture and appearance of other bonds. The main principles of operation are reduced to registration of CGS density at a certain wavelength prior to and after total dose collection. The use of helium-neon laser as a probing radiation source simplifies considerably measurement procedure and permits making measurements without sensor extraction from radiation field

  18. Radiation damage in silicon. Defect analysis and detector properties

    International Nuclear Information System (INIS)

    Silicon microstrip and pixel detectors are vital sensor-components as particle tracking detectors for present as well as future high-energy physics (HEP) experiments. All experiments at the large Hadron Collider (LHC) are equipped with such detectors. Also for experiments after the upgrade of the LHC (the so-called Super-LHC), with its ten times higher luminosity, or the planned International Linear Collider (ILC) silicon tracking detectors are forseen. Close to the interaction region these detectors have to face harsh radiation fields with intensities above the presently tolerable level. defect engineering of the used material, e. g. oxygen enrichment of high resistivity float zone silicon and growing of thin low resistivityepitaxial layers on Czochralski silicon substrates has been established to improve the radiation hardness of silicon sensors. This thesis focuses mainly on the investigation of radiation induced defects and their differences observed in various kinds of epitaxial silicon material. Comparisons with other materials like float zone or Czochralski silicon are added. Deep Level Transient Spectroscopy (DLTS) and Thermally Stimulated Current (TSC) measurements have been performed after γ-, electron-, proton- and neutron-irradiation. The differenced in the formation of vacancy and interstitial related defects as well as so-called clustered regions were investigated for various types of irradiation. In addition to the well known defects VOi, CiOi, CiCs, VP or V2 several other defect complexes have been found and investigated. Also the material dependence of the defect introduction rates and the defect annealing behavior has been studied by isothermal and isochronal annealing experiments. Especially the IO2 defect which is an indicator for the oxygen-dimer content of the material has been investigated in detail. On the basis of radiation induced defects like the bistable donor (BD) defect and a deep acceptor, a model has been introduced to describe the

  19. Radiation damage in silicon. Defect analysis and detector properties

    Energy Technology Data Exchange (ETDEWEB)

    Hoenniger, F.

    2008-01-15

    Silicon microstrip and pixel detectors are vital sensor-components as particle tracking detectors for present as well as future high-energy physics (HEP) experiments. All experiments at the large Hadron Collider (LHC) are equipped with such detectors. Also for experiments after the upgrade of the LHC (the so-called Super-LHC), with its ten times higher luminosity, or the planned International Linear Collider (ILC) silicon tracking detectors are forseen. Close to the interaction region these detectors have to face harsh radiation fields with intensities above the presently tolerable level. defect engineering of the used material, e. g. oxygen enrichment of high resistivity float zone silicon and growing of thin low resistivityepitaxial layers on Czochralski silicon substrates has been established to improve the radiation hardness of silicon sensors. This thesis focuses mainly on the investigation of radiation induced defects and their differences observed in various kinds of epitaxial silicon material. Comparisons with other materials like float zone or Czochralski silicon are added. Deep Level Transient Spectroscopy (DLTS) and Thermally Stimulated Current (TSC) measurements have been performed after {gamma}-, electron-, proton- and neutron-irradiation. The differenced in the formation of vacancy and interstitial related defects as well as so-called clustered regions were investigated for various types of irradiation. In addition to the well known defects VO{sub i}, C{sub i}O{sub i}, C{sub i}C{sub s}, VP or V{sub 2} several other defect complexes have been found and investigated. Also the material dependence of the defect introduction rates and the defect annealing behavior has been studied by isothermal and isochronal annealing experiments. Especially the IO{sub 2} defect which is an indicator for the oxygen-dimer content of the material has been investigated in detail. On the basis of radiation induced defects like the bistable donor (BD) defect and a deep

  20. Multipurpose High Sensitivity Radiation Detector: Terradex

    International Nuclear Information System (INIS)

    Terradex project aims to realise an accurate and programmable multiparametric tool which will measure relevant physical quantities such as observation time, energy and type of all decay products of three naturally occurring decay chains of uranium and thorium series present in nature as well as the decay products of man-made radioactivity. The measurements described in this work are based on the performance tests of the first version of an instrument that is designed to provide high counting accuracy, by introducing self-triggering, delayed time-coincidence technique, of products of a given decay chain. In order to qualify the technique and to calibrate the Terradex, a 222Rn source is used. The continuous and accurate monitoring of radon concentration in air is realised by observing the alpha and beta particles produced by the decay of 222Rn and its daughters and tag each of them with a precise occurrence time. The validity of delayed coincident technique by using the state of the art electronics with application of novel data sampling and analysis methods are discussed. The flexibility of sampling protocols and the advantages of online calibration capability to achieve the highest level of precision in natural and man-made radiation measurements are also described

  1. Multipurpose High Sensitivity Radiation Detector: Terradex

    Energy Technology Data Exchange (ETDEWEB)

    Alpat, Behcet [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy)]. E-mail: behcet.alpat@pg.infn.it; Aisa, Damiano [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Bizzarri, Marco [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Blasko, Sandor [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Esposito, Gennaro [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Farnesini, Lucio [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Fiori, Emmanuel [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Papi, Andrea [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Postolache, Vasile [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Renzi, Francesca [Dipartimento di Fisica dell' Universita di Perugia and INFN Sezione di Perugia (Italy); Ionica, Romeo [Politecnica University of Bucarest, Splaiul Indipendentei, Bucharest (Romania); Manolescu, Florentina [Space Science Institute of Bucharest, Maugurele, Bucharest (Romania); Ozkorucuklu, Suat [Suleyman Demirel Universitesi, Isparta (Turkey); Denizli, Haluk [Abant Izzet Baysal Universitesi, Bolu (Turkey); Tapan, Ilhan [Uludag Universitesi, Bursa (Turkey); Ercan Pilicer [Uludag Universitesi, Bursa (Turkey); Egidi, Felice [SITE Technology, Carsoli (Italy); Moretti, Cesare [SITE Technology, Carsoli(AQ) (Italy); Dicola, Luca [SITE Technology, Carsoli(AQ) (Italy)

    2007-05-11

    Terradex project aims to realise an accurate and programmable multiparametric tool which will measure relevant physical quantities such as observation time, energy and type of all decay products of three naturally occurring decay chains of uranium and thorium series present in nature as well as the decay products of man-made radioactivity. The measurements described in this work are based on the performance tests of the first version of an instrument that is designed to provide high counting accuracy, by introducing self-triggering, delayed time-coincidence technique, of products of a given decay chain. In order to qualify the technique and to calibrate the Terradex, a {sup 222}Rn source is used. The continuous and accurate monitoring of radon concentration in air is realised by observing the alpha and beta particles produced by the decay of {sup 222}Rn and its daughters and tag each of them with a precise occurrence time. The validity of delayed coincident technique by using the state of the art electronics with application of novel data sampling and analysis methods are discussed. The flexibility of sampling protocols and the advantages of online calibration capability to achieve the highest level of precision in natural and man-made radiation measurements are also described.

  2. Development of high voltage power supply for nuclear radiation detectors

    International Nuclear Information System (INIS)

    The purpose of this thesis is to develop a versatile NIM compatible high voltage power supply for proper operation of nuclear radiation detectors especially for those high resolution detectors such as semiconductor detectors, and proportional counters which require high voltage power supply with very low output ripple and high output stability. A driven type dc-ac inverter and a voltage multiplier are applied to convert a low de voltage to high dc voltage. The filter circuit is used to reduce the output ripple when the power supply is loaded and a close-loop voltage control circuit is used to minimize the drift in the output voltage. Adjustment of the output level for desired value is done through a three turn high precision potentiometer. Besides, micro-circuits are used in order to reduce undesirable temperature effect and at the same time to minimize size and weight of the high voltage module

  3. Experiences with radiation portal detectors for international rail transport

    Science.gov (United States)

    Stromswold, D. C.; McCormick, K.; Todd, L.; Ashbaker, E. D.; Evans, J. C.

    2006-08-01

    Radiation detectors monitored trains at two international borders to evaluate the performance of NaI(Tl) and plastic (polyvinyltoluene: PVT) gamma-ray detectors to characterize rail cargo. The detectors included a prototype NaI(Tl) radiation-portal-monitor panel having four large detectors (10-cm × 10-cm × 41-cm) and a PVT panel with a 41 cm × 173 cm × 3.8-cm detector. Spectral data from the NaI(Tl) and PVT detectors were recorded. Of particular emphasis was the identification of naturally occurring radioactive material (NORM) and the resultant frequency of nuisance alarms. For rail monitoring, the difficulty in stopping trains to perform secondary inspection on alarming cars creates a need for reliable identification of NORM during initial screening. Approximately 30 trains were monitored, and the commodities in individual railcars were ascertained from manifest information. At one test site, the trains carried inter-modal containers that had been unloaded from ships, and at the other site, the trains contained bulk cargo in tanker cars and hopper cars or individual items in boxcars or flatbeds. NORM encountered included potash, liquefied petroleum gas, fireworks, televisions, and clay-based products (e.g., pottery). Analysis of the spectral data included the use of the template-fitting portion of the program GADRAS developed at Sandia National Laboratories. For most of the NORM, the NaI(Tl) data produced a correct identification of the radionuclides present in the railcars. The same analysis was also used for PVT data in which the spectral information (no peaks but only gradual spectral changes including Compton edges) was limited. However, the PVT analysis provided correct identification of 40K and 226Ra in many cases.

  4. Radiation Tolerance of Aluminum Microwave Kinetic Inductance Detector

    Science.gov (United States)

    Karatsu, K.; Dominjon, A.; Fujino, T.; Funaki, T.; Hazumi, M.; Irie, F.; Ishino, H.; Kida, Y.; Matsumura, T.; Mizukami, K.; Naruse, M.; Nitta, T.; Noguchi, T.; Oka, N.; Sekiguchi, S.; Sekimoto, Y.; Sekine, M.; Shu, S.; Yamada, Y.; Yamashita, T.

    2016-08-01

    Microwave kinetic inductance detector (MKID) is one of the candidates of focal plane detector for future satellite missions such as LiteBIRD. For the space use of MKIDs, the radiation tolerance is one of the challenges to be characterized prior to the launch. Aluminum (Al) MKIDs with 50 nm thickness on silicon substrate and on sapphire substrate were irradiated with a proton beam of 160 MeV at the heavy ion medical accelerator in Chiba. The total water-equivalent absorbed dose was ˜ 10 krad which should simulate the worst radiation absorption of 5 years observation at the Lagrange point L2. We measured characteristics of these MKIDs before and after the irradiation. We found no significant changes on resonator quality factor, responsivity, and recombination time of quasi-particles. The change on electrical noise equivalent power was also evaluated, and no significant increase was found at the noise level of O(10^{-18}) W/√{ Hz }.

  5. Radiation-hard semiconductor detectors for SuperLHC

    CERN Document Server

    Bruzzi, Mara; Al-Ajili, A A; Alexandrov, P; Alfieri, G; Allport, Philip P; Andreazza, A; Artuso, M; Assouak, S; Avset, B S; Barabash, L; Baranova, E; Barcz, A; Basile, A; Bates, R; Belova, N; Betta, G F D; Biagi, S F; Bilei, G M; Bisello, D; Blue, A; Blumenau, A; Boisvert, V; Bölla, G; Bondarenko, G B; Borchi, E; Borrello, L; Bortoletto, D; Boscardin, M; Bosisio, L; Bowcock, T J V; Brodbeck, T J; Broz, J; Brukhanov, A; Brzozowski, A; Buda, M; Buhmann, P; Buttar, C; Campabadal, F; Campbell, D; Candelori, A; Casse, G; Cavallini, A; Chilingarov, A G; Chren, D; Cindro, V; Citterio, M; Collins, P; Coluccia, R; Contarato, D; Coutinho, J; Creanza, D; Cunningham, W; Cvetkov, V; Davies, G; Dawson, I; De Palma, M; Demina, R; Dervan, P; Dierlamm, A; Dittongo, S; Dobrzanski, L; Dolezal, Z; Dolgolenko, A; Eberlein, T; Eremin, V; Fall, C; Fasolo, F; Ferbel, T; Fizzotti, F; Fleta, C; Focardi, E; Forton, E; Franchenko, S; Fretwurst, E; Gamaz, F; García-Navarro, J E; García, C; Gaubas, E; Genest, M H; Gill, K A; Giolo, K; Glaser, M; Gössling, C; Golovine, V; Gorelov, I; Goss, J; Gouldwell, A; Grégoire, G; Gregori, P; Grigoriev, E; Grigson, C; Grillo, A; Groza, A; Guskov, J; Haddad, L; Harding, R; Härkönen, J; Hauler, F; Hayama, S; Hoeferkamp, M; Honniger, F; Horazdovsky, T; Horisberger, R P; Horn, M; Houdayer, A; Hourahine, B; Hruban, A; Hughes, G; Ilyashenko, Yu S; Irmscher, K; Ivanov, A; Jarasiunas, K; Jin, T; 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 P; Kierstead, J A; Klaiber Lodewigs, J M; Kleverman, M; Klingenberg, R; Kodys, P; Kohout, Z; Korjenevski, S; Kowalik, A; Kozlowski, R; Kozodaev, M; Kramberger, G; Krasel, O; Kuznetsov, A; Kwan, S; Lagomarsino, S; Lari, T; Lassila-Perini, K M; Lastovetsky, V F; Latino, G; Latushkin, S T; Lazanu, I; Lazanu, S; Lebel, C; Leinonen, K; Leroy, C; Li, Z; Lindström, G; Lindström, L; Linhart, V; Litovchenko, A P; Litovchenko, P G; Litvinov, V; Lo Giudice, A; Lozano, M; Luczynski, Z; Luukka, Panja; Macchiolo, A; Mainwood, A; Makarenko, L F; Mandic, I; Manfredotti, C; Martí i García, S; Marunko, S; Mathieson, K; Melone, J; Menichelli, D; Meroni, C; Messineo, A; Miglio, S; Mikuz, M; Miyamoto, J; Moll, M; Monakhov, E; Moscatelli, F; Mozzanti, A; Murin, L; Naoumov, D; Nava, F; Nossarzhevska, E; Nummela, S; Nysten, J; Olivero, P; O'Shea, V; Palviainen, T; Paolini, C; Parkes, C; Passeri, D; Pein, U; Pellegrini, G; Perera, L; Petasecca, M; Piatkowski, B; Piemonte, C; Pignatel, G U; Pinho, N; Pintilie, I; Pintilie, L; Polivtsev, L; Polozov, P; Popa, A I; Popule, J; Pospísil, S; Pucker, G; Radicci, V; Rafí, J M; Ragusa, F; Rahman, M; Rando, R; Röder, R; Rohe, T; Ronchin, S; Rott, C; Roy, A; Roy, P; Ruzin, A; Ryazanov, 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 J; Sentenac, D; Sevilla, S G; Shipsey, I; Sícho, P; Sloan, T; Solar, M; Son, S; Sopko, B; Spencer, N; Stahl, J; Stavitski, I; Stolze, D; Stone, R; Storasta, J; Strokan, N; Strupinski, W; Sudzius, M; Surma, B; Suuronen, J; Suvorov, A; Svensson, B G; Tipton, P; Tomasek, M; Troncon, C; Tsvetkov, A; Tuominen, E; Tuovinen, E; Tuuva, T; Tylchin, M; Uebersee, H; Uher, J; Ullán, M; Vaitkus, J V; Vanni, P; Velthuis, J; Verbitskaya, E; Verzellesi, G; Vrba, V; Wagner, G; Wilhelm, I; Worm, S; Wright, V; Wunstorf, R; Zabierowski, P; Zaluzhny, A; Zavrtanik, M; Zen, M; Zhukov, V; Zorzi, N; de Boer, Wim

    2005-01-01

    An option of increasing the luminosity of the Large Hadron Collider (LHC) at CERN to 10/sup 35/ cm-/sup 2/s-/sup 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 interaction region will receive severe doses of fast hadron irradiation and the inner tracker detectors will need to survive fast hadron fluences of up to above 10 /sup 16/ cm-/sup 2/. The CERN-RD50 project "Development of Radiation Hard Semiconductor Devices for Very High Luminosity Colliders" has been established in 2002 to explore detector materials and technologies that will allow to operate devices up to, or beyond, this limit. The strategies followed by RD50 to enhance the radiation tolerance include the development of new or defect engineered detector materials (SiC, GaN, Czochralski and epitaxial silicon, oxygen enriched Flo...

  6. Low Cost Long Distance Detector for Explosives and Chemical Analysis by IEC Application

    Directory of Open Access Journals (Sweden)

    George H. Miley

    2005-01-01

    Full Text Available A radiation source for detecting specific chemicals at several meter distances even behind walls, car doors or other barriers is the application of Million electron Volts (MeV neutrons from nuclear fusion reactions at such low intensities to avoid any danger for human bodies. The chemical analysis consists in the neutron activation of nuclei emitting then gamma radiation of lines very specific for the excited nuclei. The neutron generation by the Inertial Electrostatic Confinement (IEC had been developed to a level where very low cost neutron generators in mass production may be developed with a power supply from a normal AC plug-in or a battery. For specific chemicals e.g. the ratio of nitrogen against other elements used in all explosives, the selection of few specific gamma lines for the detectors may be of sufficiently low cost in the case of mass production.

  7. VeriTainer radiation detector for intermodal shipping containers

    International Nuclear Information System (INIS)

    The VeriSpreaderTM radiation detection system will monitor every container passing through a shipping terminal without impeding the flow of commerce by making the radiation measurements during normal container handling. This is accomplished by integrating neutron and spectroscopic γ-ray detectors into a container crane spreader bar, the part of the crane that directly engages the intermodal shipping containers while moving from ship to shore and vice versa. The use of a spectroscopic γ-detector reduces the rate of nuisance alarms due to naturally occurring radioactive material (NORM). The combination of γ and neutron detection reduces the effectiveness of shielding and countermeasures. The challenges in this spreader bar-based approach arise from the harsh environment, particularly the mechanical shock and the vibration of the moving spreader bar, since the measurement is taken while the container is moving. The electrical interfaces in the port environment, from the crane to a central monitoring office, present further challenges. It is the packaging, electronic interfaces, and data processing software that distinguish this system, which is based on conventional radiation sensors. The core of the system is Amptek's GAMMA-RAD, which integrates a ruggedized scintillator/PMT, digital pulse shaping electronics, electronics for the neutron detector, power supplies, and an Ethernet interface. The design of the VeriTainer system and results from both the laboratory and a proof-of-concept test at the Port of Oakland, California will be presented

  8. Radiation monitoring of the GEM muon detectors at CMS

    Science.gov (United States)

    Dimitrov, L.; Iaydjiev, P.; Mitev, G.; Vankov, I.

    2016-09-01

    The higher energy and luminosity of future High Luminosity (HL) LHC, determines a significant increasing of the radiation background around the CMS subdetectors, and especially in the higher pseudorapidity region. Under such heavy conditions, the RPC (used in muon trigger) most probably could not operate effectively. GEM (Gas Electron Multiplier) detectors have been identified as a suitable technology to operate in the high radiation environment in that region and test at CMS will start in 2016. A monitoring system to control the absorbed radiation dose by the GEM under test is developed. Two types of sensors are used in it: RadFETs for total absorbed dose and p-i-n diodes for particle (proton and neutron) detection. The basic detector unit, called RADMON, contains two sensors of each type and can be installed at each GEM detector. The system has a modular structure, permitting to increase easily the number of controlled RADMONs: one module controls up to 12 RADMONs, organized in three group of four and communicates outside by RS 485 and CANBUS interfaces.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyong Sei; Hong, Byung Sik; Park, Sung Keun [Korea University, Seoul (Korea, Republic of); Kim, Sang Yeol [NoticeKorea, Anyang (Korea, Republic of)

    2014-11-15

    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 x 16 cm{sup 2} 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 x 10{sup 6} Hz cm{sup -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.

  10. Mobile robot prototype detector of gamma radiation; Prototipo de robot movil detector de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez C, R.M. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Duran V, M. D.; Jardon M, C. I., E-mail: raulmario.vazquez@inin.gob.mx [Tecnologico de Estudios Superiores de Villa Guerrero, Carretera Federal Toluca-Ixtapan de la Sal Km. 64.5, La Finca Villa Guerrero, Estado de Mexico (Mexico)

    2014-10-15

    In this paper the technological development of a mobile robot prototype detector of gamma radiation is shown. This prototype has been developed for the purpose of algorithms implementation for the applications of terrestrial radiation monitoring of exposed sources, search for missing radioactive sources, identification and delineation of radioactive contamination areas and distribution maps generating of radioactive exposure. Mobile robot detector of radiation is an experimental technology development platform to operate in laboratory environment or flat floor facilities. The prototype integrates a driving section of differential configuration robot on wheels, a support mechanism and rotation of shielded detector, actuator controller cards, acquisition and processing of sensor data, detection algorithms programming and control actuators, data recording (Data Logger) and data transmission in wireless way. The robot in this first phase is remotely operated in wireless way with a range of approximately 150 m line of sight and can extend that range to 300 m or more with the use of signal repeaters. The gamma radiation detection is performed using a Geiger detector shielded. Scan detection is performed at various time sampling periods and diverse positions of discrete or continuous angular orientation on the horizon. The captured data are geographical coordinates of robot GPS (latitude and longitude), orientation angle of shield, counting by sampling time, date, hours, minutes and seconds. The data is saved in a file in the Micro Sd memory on the robot. They are also sent in wireless way by an X Bee card to a remote station that receives for their online monitoring on a laptop through an acquisition program by serial port on Mat Lab. Additionally a voice synthesizing card with a horn, both in the robot, periodically pronounced in Spanish, data length, latitude, orientation angle of shield and detected accounts. (Author)

  11. Natural radiation, nuclear wastes and chemical pollutants

    International Nuclear Information System (INIS)

    Doses from natural radiation to the population in the Nordic Countries are summarized and man made modifications of the natural radiation environment are discussed. An account is given of the radiological consequences of energy conservation by reduced ventilation. Risks from possible future releases of radioactivity from final repositories of spent nuclear fuel are compared to the risks from present natural radioactivity in the environment. The possibilities for comparison between chemical and radiological risks are discussed. (author) 13 refs

  12. [Influence of Detector Radiation Damage on CR Mammography Quality Control].

    Science.gov (United States)

    Moriwaki, Atsumi; Ishii, Mie; Terazono, Shiho; Arao, Keiko; Ishii, Rie; Sanada, Taizo; Yoshida, Akira

    2016-05-01

    Recently, radiation damage to the detector apparatus employed in computed radiography (CR) mammography has become problematic. The CR system and the imaging plate (IP) applied to quality control (QC) program were also used in clinical mammography in our hospital, and the IP to which radiation damage has occurred was used for approximately 5 years (approximately 13,000 exposures). We considered using previously acquired QC image data, which is stored in a server, to investigate the influence of radiation damage to an IP. The mammography unit employed in this study was a phase contrast mammography (PCM) Mermaid (KONICA MINOLTA) system. The QC image was made newly, and it was output in the film, and thereafter the optical density of the step-phantom image was measured. An input (digital value)-output (optical density) conversion curve was plotted using the obtained data. The digital values were then converted to optical density values using a reference optical density vs. digital value curve. When a high radiation dose was applied directly, radiation damage occurred at a position on the IP where no object was present. Daily QC for mammography is conducted using an American College of Radiology (ACR) accreditation phantom and acrylic disc, and an environmental background density measurement is performed as one of the management indexes. In this study, the radiation damage sustained by the acrylic disc was shown to differ from that of the background. Thus, it was revealed that QC results are influenced by radiation damage. PMID:27211088

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-07-01

    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 thickness in front of them. The measured TL signal in the 0.1 mm thick detector just shielded by an aluminised Kapton foil of 25 {mu}m thickness in front yielded a dose of 29.8 Gy (calibrated with {sup 137}Cs gamma rays) for an exposure time of 12.7 days; after 2.5 gcm{sup -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 the open space. The knowledge of depth-dose distribution is a prerequisite to determine the organ doses an astronaut will receive during an extravehicular activity. The BIOPAN experiments are to be continued in the future. (author)

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

    Science.gov (United States)

    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

  17. Development of the mercury iodide semiconductor crystal for application as a radiation detector

    International Nuclear Information System (INIS)

    In this work, the establishment of a technique for HgI growth and preparation of crystals, for use as room temperature radiation semiconductor detectors is described. Three methods of crystal growth were studied while developing this work: physical vapor transport (PVT); saturated solution of HgI2, using two different solvents; (a) dimethyl sulfoxide (DMSO) and (b) acetone, and the Bridgman method. In order to evaluate the obtained crystals by the three methods, systematic measurements were carried out for determining the stoichiometry, structure, orientation, surface morphology and impurity of the crystal. The influence of these physical chemical properties on the crystals development was studied, evaluating their performance as radiation detectors. The X-ray diffractograms indicated that the crystals were, preferentially, oriented in the (001) e (101) directions with tetragonal structure for all crystals. Nevertheless, morphology with a smaller deformation level was observed for the crystal obtained by the PVT technique, comparing to other methods. Uniformity on the surface layer of the PVT crystal was detected, while clear incrustations of elements distinct from the crystal could be viewed on the DMSO crystal surface. The best results as to radiation response were found for the crystal grown by physical vapor transport. Significant improvement in the HgIz2 radiation detector performance was achieved for purer crystals, growing the crystal twice by PVT technique. (author)

  18. Joint chemical agent detector (JCAD): the future of chemical agent detection

    Science.gov (United States)

    Laljer, Charles E.

    2003-08-01

    The Joint Chemical Agent Detector (JCAD) has continued development through 2002. The JCAD has completed Contractor Validation Testing (CVT) that included chemical warfare agent testing, environmental testing, electromagnetic interferent testing, and platform integration validation. The JCAD provides state of the art chemical warfare agent detection capability to military and homeland security operators. Intelligence sources estimate that over twenty countries have active chemical weapons programs. The spread of weapons of mass destruction (and the industrial capability for manufacture of these weapons) to third world nations and terrorist organizations has greatly increased the chemical agent threat to U.S. interests. Coupled with the potential for U.S. involvement in localized conflicts in an operational or support capacity, increases the probability that the military Joint Services may encounter chemical agents anywhere in the world. The JCAD is a small (45 in3), lightweight (2 lb.) chemical agent detector for vehicle interiors, aircraft, individual personnel, shipboard, and fixed site locations. The system provides a common detection component across multi-service platforms. This common detector system will allow the Joint Services to use the same operational and support concept for more efficient utilization of resources. The JCAD detects, identifies, quantifies, and warns of the presence of chemical agents prior to onset of miosis. Upon detection of chemical agents, the detector provides local and remote audible and visual alarms to the operators. Advance warning will provide the vehicle crew and other personnel in the local area with the time necessary to protect themselves from the lethal effects of chemical agents. The JCAD is capable of being upgraded to protect against future chemical agent threats. The JCAD provides the operator with the warning necessary to survive and fight in a chemical warfare agent threat environment.

  19. Photoluminescence and Photonics: from miniaturised light sources to radiation detectors

    International Nuclear Information System (INIS)

    Photonics is the science of the harnessing of light. Photonics encompasses the generation of light, the detection of light, the management of light through guidance, manipulation, and amplification. Luminescence phenomena are widely used in solid state light sources and radiation detectors based on point defects in insulators. Among them, 2 ed F3+ aggregate colour centres are induced in lithium fluoride (LiF) by various kinds of ionizing radiation and are laser active in the visible spectral region. They have been studied and successfully used at Frascati ENEA Research Centre for realizing prototypes of both miniaturized light sources, in the form of waveguides and vertical optical micro cavities for integrated optics, and of novel X-ray imaging detectors, based on the optical reading of photoluminescence of the locally induced defects. The highest intrinsic spatial resolution on a wide field of view and their versatility, achieved by the growth of LiF thin films by thermal evaporation, allow using such detectors in the frameworks of nano photonics, life science and energy. Recently, they have been also used in the advanced diagnostics of proton beams, with promising results in imaging and dosimetry based on photoluminescence

  20. Semiconductor scintillator detector for gamma radiation; Detector cintilador semicondutor para radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Laan, F.T.V. der; Borges, V.; Zabadal, J.R.S., E-mail: ftvdl@ufrgs.br, E-mail: borges@ufrgs.br, E-mail: jorge.zabadal@ufrgs.br [Universidade Federal do Rio Grande do Sul (GENUC/DEMEC/UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares. Departamento de Engenharia Mecanica

    2015-07-01

    Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

  1. SENTIRAD-An innovative personal radiation detector based on a scintillation detector and a silicon photomultiplier

    International Nuclear Information System (INIS)

    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.

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

    Science.gov (United States)

    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.

  3. Intrinsic Radiation in Lutetium Based PET Detector: Advantages and Disadvantages

    CERN Document Server

    Wei, Qingyang

    2015-01-01

    Lutetium (Lu) based scintillators such as LSO and LYSO, are widely used in modern PET detectors due to their high stopping power for 511 keV gamma rays, high light yield and short decay time. However, 2.6% of naturally occurring Lu is 176Lu, a long-lived radioactive element including a beta decay and three major simultaneous gamma decays. This phenomenon introduces random events to PET systems that affects the system performance. On the other hand, the advantages of intrinsic radiation of 176Lu (IRL) continues to be exploited. In this paper, research literatures about IRL in PET detectors are reviewed. Details about the adverse effects of IRL to PET and their solutions, as well as the useful applications are presented and discussed.

  4. Silicon detectors operating beyond the LHC collider conditions: scenarios for radiation fields and detector degradation

    International Nuclear Information System (INIS)

    Particle physics makes its greatest advances with experiments at the highest energies. The way to advance to a higher energy regime is through hadron colliders, or through non-accelerator experiments, as for example the space astroparticle missions. In the near future, the Large Hadron Collider (LHC) will be operational, and beyond that, its upgrades: the Super-LHC (SLHC) and the hypothetical Very Large Hadron Collider (VLHC). At the present time, there are no detailed studies for future accelerators, except those referring to LHC. For the new hadron collider LHC and some of its updates in luminosity and energy, the silicon detectors could represent an important option, especially for the tracking system and calorimetry. The main goal of this paper is to analyse the expected long-time degradation of the silicon as material and for silicon detectors, during continuous radiation, in these hostile conditions. The behaviour of silicon in relation to various scenarios for upgrade in energy and luminosity is discussed in the frame of a phenomenological model developed previously by the authors and now extended to include new mechanisms, able to explain and give solutions to discrepancies between model predictions and detector behaviour after hadron irradiation. Different silicon material parameters resulting from different technologies are considered to evaluate what materials are harder to radiation and consequently could minimise the degradation of device parameters in conditions of continuous long time operation. (authors)

  5. Chemical radiation protection in mammals and humans

    International Nuclear Information System (INIS)

    The development and the present situation in experimental research with animals as well as in clinical application in the field of chemical radioprotection are described. The efficacy of radioprotective substances in the case of acute radiation death, of radiation-induced changes in various tissues and organs as well as in late effects are reported. The mechanisms of actions are discussed. By comparison of radiation reactions in protected and unprotected animals radioprotective factors can be determined. Such factors depend, among other parameters, on the kind of the radioprotective agent and its dose, on the radiation reaction, on the quality of radiation as well as on the radiation dose. Up to now thiophosphate WR 2721 proved to be the most efficient substance. It was observed that the application of this compound yielded a protection factor of up to 2.7 for the acute radiation death in mice. The disadvantage of radioprotective agents must be seen in their side effects. Despite this behaviour thiophosphate, amongst others, is being tested in clinical radiotherapy. In order to apply radioprotective substances in foreseen emergency or catastrophic situations a number of demands were postulated. As yet, none of the tested radioprotectors meet these demands. Therefore, NATO has refrained from keeping radioprotective agents in reserve up to now. On the other hand, the USSR has included the radioprotective agent cystamine in their civil defence protection kit. (orig.)

  6. Chemical protection against ionizing radiation. Final report

    International Nuclear Information System (INIS)

    The scientific literature on radiation-protective drugs is reviewed. Emphasis is placed on the mechanisms involved in determining the sensitivity of biological material to ionizing radiation and mechanisms of chemical radioprotection. In Section I, the types of radiation are described and the effects of ionizing radiation on biological systems are reviewed. The effects of ionizing radiation are briefly contrasted with the effects of non-ionizing radiation. Section II reviews the contributions of various natural factors which influence the inherent radiosensitivity of biological systems. Inlcuded in the list of these factors are water, oxygen, thiols, vitamins and antioxidants. Brief attention is given to the model describing competition between oxygen and natural radioprotective substances (principally, thiols) in determining the net cellular radiosensitivity. Several theories of the mechanism(s) of action of radioprotective drugs are described in Section III. These mechanisms include the production of hypoxia, detoxication of radiochemical reactive species, stabilization of the radiobiological target and the enhancement of damage repair processes. Section IV describes the current strategies for the treatment of radiation injury. Likely areas in which fruitful research might be performed are described in Section V. 495 references

  7. Chemical protection against ionizing radiation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Livesey, J.C.; Reed, D.J.; Adamson, L.F.

    1984-08-01

    The scientific literature on radiation-protective drugs is reviewed. Emphasis is placed on the mechanisms involved in determining the sensitivity of biological material to ionizing radiation and mechanisms of chemical radioprotection. In Section I, the types of radiation are described and the effects of ionizing radiation on biological systems are reviewed. The effects of ionizing radiation are briefly contrasted with the effects of non-ionizing radiation. Section II reviews the contributions of various natural factors which influence the inherent radiosensitivity of biological systems. Inlcuded in the list of these factors are water, oxygen, thiols, vitamins and antioxidants. Brief attention is given to the model describing competition between oxygen and natural radioprotective substances (principally, thiols) in determining the net cellular radiosensitivity. Several theories of the mechanism(s) of action of radioprotective drugs are described in Section III. These mechanisms include the production of hypoxia, detoxication of radiochemical reactive species, stabilization of the radiobiological target and the enhancement of damage repair processes. Section IV describes the current strategies for the treatment of radiation injury. Likely areas in which fruitful research might be performed are described in Section V. 495 references.

  8. Intrinsic Radiation in Lutetium Based PET Detector: Advantages and Disadvantages

    OpenAIRE

    Wei, Qingyang

    2015-01-01

    Lutetium (Lu) based scintillators such as LSO and LYSO, are widely used in modern PET detectors due to their high stopping power for 511 keV gamma rays, high light yield and short decay time. However, 2.6% of naturally occurring Lu is 176Lu, a long-lived radioactive element including a beta decay and three major simultaneous gamma decays. This phenomenon introduces random events to PET systems that affects the system performance. On the other hand, the advantages of intrinsic radiation of 176...

  9. A Study of an Acrylic Cerenkov Radiation Detector

    CERN Document Server

    Porter, B; De Barbaro, P; Bodek, Arie; Budd, H S

    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 nuclear physics experiments, as well as to analysis techniques involving Poisson statistics. [to be published in Am. J. Phys. 67 (Oct/Nov 1999).

  10. High-Speed, Low Power 256 Channel Gamma Radiation Array Detector ASIC Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Building on prior success in detector electronics, we propose to design and fabricate a 256 channel readout ASIC for solid state gamma radiation array detectors...

  11. Response of personal radiation detectors to simulated criticality accident pulses

    International Nuclear Information System (INIS)

    Personal radiation detection instruments (PRDIs) are often used to augment the protection provided by the installed criticality accident alarm system (CAAS). ANSI/ANS-8.3-1997 provides examples of situations when PRDIs could be used, including hor ellipsisalarm system maintenance or testing, evacuation drills, activities in areas not normally occupied by personnel, or other special operations. These instruments were designed for use in radiological control applications. Consequently, documented performance capabilities under conditions typical of the initial pulse from a criticality accident are not readily available. This paper describes testing performed to demonstrate the capability of the PRDIs to respond to radiation pulses similar to that which would be expected to occur in the event of a criticality accident. Detector responses for low-power, oscillating, or slow excursions were either available from manufacturing data or bounded by the initial pulse

  12. Advanced radiation detector development mercuric iodide, silicon with internal gain, hybrid scintillator/semiconductor detectors. Comprehensive summary report, 1976-1985

    International Nuclear Information System (INIS)

    Accomplishments are reported in the development of a compound semi-insulator mercuric iodide (HgI2) for nuclear radiation detection and spectroscopy, early lung cancer detection and localization in the uranium miner/worker population, computer digital image processing and image reconstruction research, and a concept for multiple, filtered x-ray computed tomography scanning to reveal chemical compositional information. Another area of interest is the study of new advances in the area of silicon detectors with internal gain (''avalanche'')

  13. Microscopic model for chemical etchability along radiation damage paths in solids

    Institute of Scientific and Technical Information of China (English)

    Mukhtar Ahmed RANA

    2008-01-01

    It would be very interesting to develop a picture about removal of atoms from the radiation damaged paths or latent nuclear tracks and undamaged bulk material in track detectors. Here, theory of chemical etching is described briefly and a new model for chemical etching along radiation damaged paths in solids is developed based on basic scientific facts and valid assumptions. Dependence of chemical etching on radiation damage intensity and etching conditions is discussed. A new parameter for etching along radiation damaged paths is introduced, which is useful for investigation of relationship between chemical etchability and radiation damage in a solid. Results and discussion presented here are also useful for further development of nuclear waste immobilization.

  14. Development of Personal Radiation Detector Instrument with Multi Channel Analyzer and Wireless Communication

    International Nuclear Information System (INIS)

    According to the Department of Homeland Security specifications regarding illicit traffic of nuclear materials, a Personal Radiation Detector has been developed. Personal Radiation Detectors are small, lightweight radiation monitors worn on the body, used to detect the presence of or to search for gamma and neutron radiation. This type of instrument can be supplied to unprofessional radiation trained personnel for detection and alert of radioactive materials. A wireless connection of Personal Radiation Detector instruments to a remote risk assessment center increases the possibly to contain a radiological incident in its beginning, until the nuclear Hazards Materials specialists estimate and evaluate the event. Integrating spectrometry capability and wireless communication into the Personal Radiation Detector has many advantages. For example, energy spectrum can be transmitted from the field in real time, enabling the specialist at the risk assessment center to manage the control actions in an event involving the presence of radioactive materials. A Personal Radiation Detector developed instrument, the Personal Detector system-100, includes internal low power Multi Channel Analyzer and Blue Tooth wireless communication. The detector includes neutron and gamma scintillators, a tube, novel pulse processing electronics and sophisticated software. In order to decrease the power consumption, a Cockcroft Walton type power supply was developed. The Personal Radiation Detector software enables fast alert in case of radiation increase over background. This work introduces the Multi Channel Analyzer design approach and experiments results showing the actual performances of the Personal Detector system-100

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

    International Nuclear Information System (INIS)

    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

  16. Processing and characterization of epitaxial GaAs radiation detectors

    Science.gov (United States)

    Wu, X.; Peltola, T.; 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.

    2015-10-01

    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 - 130 μm 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 μm / 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 (Vfd) of the detectors with 110 μm epi-layer thickness is in the range of 8-15 V and the leakage current density is about 10 nA/cm2. 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 velocity of electrons in GaAs at a given thickness. Numerical simulations with an appropriate defect model agree with the experimental results.

  17. Large area radiation detectors based on II VI thin films

    Science.gov (United States)

    Quevedo-Lopez, Manuel

    2015-03-01

    The development of low temperature device technologies that have enabled flexible displays also present opportunities for flexible electronics and flexible integrated systems. Of particular interest are possible applications in flexible, low metal content, sensor systems for unattended ground sensors, smart medical bandages, electronic ID tags for geo-location, conformal antennas, neutron/gamma-ray/x-ray detectors, etc. In this talk, our efforts to develop novel CMOS integration schemes, circuits, memory, sensors as well as novel contacts, dielectrics and semiconductors for flexible electronics are presented. In particular, in this presentation we discuss fundamental materials properties including crystalline structure, interfacial reactions, doping, etc. defining performance and reliability of II-VI-based radiation sensors. We investigate the optimal thickness of a semiconductor diode for thin-film solid state thermal neutron detectors. Besides II-VI materials, we also evaluated several diode materials, Si, CdTe,GaAs, C (diamond), and ZnO, and two neutron converter materials,10B and 6LiF. We determine the minimum semiconductor thickness needed to achieve maximum neutron detection efficiency. By keeping the semiconductor thickness to a minimum, gamma rejection is kept as high as possible. In this way, we optimize detector performance for different thin-film semiconductor materials.

  18. Radiation Tolerance of Cryogenic Beam Loss Monitor Detectors

    CERN Document Server

    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. Processing and characterization of epitaxial GaAs radiation detectors

    CERN Document Server

    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...

  20. Nuclear Track Detectors for Environmental Studies and Radiation Monitoring

    CERN Document Server

    Manzoor, S; Cozzi, M; Errico, M; Giacomelli, G; Giorgini, M; Kumar, A; Margiotta, A; Medinaceli, E; Patrizii, L; Popa, V; Qureshi, I E; Togo, V

    2007-01-01

    Several improvements were made for Nuclear Track Detectors (NTDs) used for environmental studies and for particle searches. A new method was used to determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the simultaneous measurement of the diameter and of the height of etch-pit cones caused by relativistic heavy ions (158 A GeV Pb(82+) and In(49+) ions) and their fragments. The use of alcohol in the etching solution improves the surface quality of NTDs and it raises their thresholds. The detectors were used for the determination of nuclear fragmentation cross sections of Iron and Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for the determination of doses in hadron therapy and for doses received by astronauts. The detectors were also used in the search of massive particles in the cosmic radiation, for the determination of the mass spectrum of cosmic rays and for the evaluation of Po(210) alpha decay and of natural radon concentrations.

  1. Nuclear Track Detectors for Environmental Studies and Radiation Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Manzoor, S. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); PRD, PINSTECH, P.O. Nilore, Islamabad (Pakistan); COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan)], E-mail: manzoor@bo.infn.it; Balestra, S.; Cozzi, M.; Errico, M.; Giacomelli, G.; Giorgini, M. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Kumar, A. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Dept. of Physics, Sant Longowal Institute of Eng. and Tech., Longowal 148 106 India (India); Margiotta, A.; Medinaceli, E.; Patrizii, L. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Popa, V. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Institute of Space Sciences, Bucharest R-77125 (Romania); Qureshi, I.E. [PRD, PINSTECH, P.O. Nilore, Islamabad (Pakistan); COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Togo, V. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy)

    2007-10-15

    Several improvements were made for Nuclear Track Detectors (NTDs) used for environmental studies and for particle searches. A new method was used to determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the simultaneous measurement of the diameter and of the height of etch-pit cones caused by relativistic heavy ions (158 A GeV Pb{sup 82+} and In{sup 49+} ions) and their fragments. The use of alcohol in the etching solution improves the surface quality of NTDs and it raises their thresholds. The detectors were used for the determination of nuclear fragmentation cross sections of Iron and Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for the determination of doses in hadrontherapy and for doses received by astronauts. The detectors were also used in the search of massive particles in the cosmic radiation, for the determination of the mass spectrum of cosmic rays and for the evaluation of Po{sup 210}{alpha}-decay and of natural radon concentrations.

  2. Laser system for testing radiation imaging detector circuits

    Science.gov (United States)

    Zubrzycka, Weronika; Kasinski, Krzysztof

    2015-09-01

    Performance and functionality of radiation imaging detector circuits in charge and position measurement systems need to meet tight requirements. It is therefore necessary to thoroughly test sensors as well as read-out electronics. The major disadvantages of using radioactive sources or particle beams for testing are high financial expenses and limited accessibility. As an alternative short pulses of well-focused laser beam are often used for preliminary tests. There are number of laser-based devices available on the market, but very often their applicability in this field is limited. This paper describes concept, design and validation of laser system for testing silicon sensor based radiation imaging detector circuits. The emphasis is put on keeping overall costs low while achieving all required goals: mobility, flexible parameters, remote control and possibility of carrying out automated tests. The main part of the developed device is an optical pick-up unit (OPU) used in optical disc drives. The hardware includes FPGA-controlled circuits for laser positioning in 2 dimensions (horizontal and vertical), precision timing (frequency and number) and amplitude (diode current) of short ns-scale (3.2 ns) light pulses. The system is controlled via USB interface by a dedicated LabVIEW-based application enabling full manual or semi-automated test procedures.

  3. Radiation loads of the detectors for the central region of the LHCb experiment at LHC

    CERN Document Server

    Talanov, V V

    2002-01-01

    The formation of the secondary-radiation field in the central region of the future LHCb experiment at LHC (CERN) was numerically simulated. The specific features of the field characteristics were revealed for different configurations of detectors in the experiment. The radiation loads governing the detector operation in a given radiation environment were evaluated. Methods for optimizing the design of the detectors and the accelerator vacuum chamber were proposed. (15 refs).

  4. Radiation flaw detector for testing non-uniform surface bodies of revolution

    International Nuclear Information System (INIS)

    Radiation flaw detector for testing bodies of revolution with non-uniform surface, welded joints, etc., based on spatial filtration and differentiation of ionizing radiation flux has been described. The calculation of the most important unit of flaw detector - integrators - is made. Experimental studies of the sensitivity have shown, that the radiation flaw detector can be used for rapid testing of products with the sensitivity comparable with the sensitivity of radiographic testing of steel

  5. Study of chemical and radiation induced carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  6. Experimental investigation of the radiation shielding efficiency of a MCP detector in the radiation environment near Jupiter's moon Europa

    Science.gov (United States)

    Tulej, M.; Meyer, S.; Lüthi, M.; Lasi, D.; Galli, A.; Piazza, D.; Desorgher, L.; Reggiani, D.; Hajdas, W.; Karlsson, S.; Kalla, L.; Wurz, P.

    2016-09-01

    Neutral Ion Mass spectrometer (NIM) is one of the instruments in the Particle Environmental Package (PEP) designed for the JUICE mission of ESA to the Jupiter system. NIM, equipped with a sensitive MCP ion detector, will conduct detailed measurements of the chemical composition of Jovian icy moons exospheres. To achieve high sensitivity of the instrument, radiation effects due to the high radiation background (high-energy electrons and protons) around Jupiter have to be minimised. We investigate the performance of an Al-Ta-Al composite stack as a potential shielding against high-energy electrons. Experiments were performed at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute, Villigen, Switzerland. The facility delivers a particle beam containing e-, μ- and π- with momentum from 17.5 to 345 MeV/c (Hajdas et al., 2014). The measurements of the radiation environment generated during the interaction of primary particles with the Al-Ta-Al material were conducted with dedicated beam diagnostic methods and with the NIM MCP detector. In parallel, modelling studies using GEANT4 and GRAS suites were performed to identify products of the interaction and predict ultimate fluxes and particle rates at the MCP detector. Combination of experiment and modelling studies yields detailed characterisation of the radiation fields produced by the interaction of the incident e- with the shielding material in the range of the beam momentum from 17.5 to 345 MeV/c. We derived the effective MCP detection efficiency to primary and secondary radiation and effective shielding transmission coefficients to incident high-energy electron beam in the range of applied beam momenta. This study shows that the applied shielding attenuates efficiently high-energy electrons. Nevertheless, owing to nearly linear increase of the bremsstrahlung production rate with incident beam energy, above 130 MeV their detection rates measured by the MCP

  7. Modifications of radiation detection response of PADC track detectors by photons

    CERN Document Server

    Sinha, D

    1998-01-01

    Photon induced modifications in polyalyldiglycol carbonate (PADC) track detectors have been studied in the dose range of 10 sup 1 -10 sup 6 Gy. It was found that some of the properties like bulk-etch rate, track-etch rate got enhanced at the dose of 10 sup 6 Gy. Activation energy for bulk-etching has been determined for different gamma doses. In order to correlate the high etch rate with the chemical modifications, UV-Vis, IR and ESR studies were carried out. These studies clearly give the indication that radiation damage results into radical formation through bond cleavage. TGA study was performed for understanding the thermal resistance of this detector. The results are presented and discussed.

  8. Chemical protection against ionizing radiation: a survey of possible mechanisms

    International Nuclear Information System (INIS)

    A comparative survey is given of the hypotheses which have been proposed to explain the protecting and sensitizing action of chemical substances towards ionizing radiation such as gamma radiation or x radiation

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-21

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Field Deployable Gamma Radiation Detectors for DHS Use

    Energy Technology Data Exchange (ETDEWEB)

    Sanjoy Mukhopadhyay

    2007-08-01

    Recently, the 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 off-the-shelf 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 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{trademark}, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, 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{trademark} 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, better resolution, and 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 automatically triggers the saving of relevant

  13. Next Generation Semiconductor-Based Radiation Detectors Using Cadmium Magnesium Telluride

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Fabrication and performance of p-i-n CdTe radiation detectors

    International Nuclear Information System (INIS)

    We report on the fabrication and performance of CdTe radiation detectors in a new p-i-n structure which helps to reduce the leakage current to a minimum level. Chlorine-doped single-crystal CdTe substrates having resistivity in the order of 109 Ω cm were used in this study. Iodine-doped n-type CdTe layers were grown homoepitaxially on one face of each crystals using the hydrogen plasma-radical-assisted metalorganic chemical vapor deposition technique at low substrate temperature of 150 deg. C. Indium electrode was evaporated on the n-CdTe side while a gold electrode on the opposite side acted as a p-type contact. Detectors thus fabricated exhibited low leakage current (below 0.4 nA/mm2 at 250 V applied reverse bias for the best one) and good performance at room temperature. Spectral response of the detectors showed improved energy resolution for Am-241, Co-57, and Cs-137 radioisotopes. Detectors were further tested with X-ray photons of different intensities for their potential application in imaging systems and promising responses were obtained

  15. Construction and performance of the ALICE Transition Radiation Detector

    Energy Technology Data Exchange (ETDEWEB)

    Emschermann, David

    2010-01-20

    The Transition Radiation Detector (TRD) has been designed to identify electrons in the pion dominated background of heavy-ions collisions. As electrons do not interact strongly, they allow to probe the early phase of the interaction. As trigger on high-p{sub t} e{sup +}e{sup -} pairs within 6.5 {mu}s after collision, the TRD can initiate the readout of the Time Projection Chamber (TPC). The TRD is composed of 18 super modules arranged in a barrel geometry in the central part of the ALICE detector. It offers almost 1.2 million readout channels on a total area of close to 700 m{sup 2}. The particle detection properties of the TRD depend crucially on details in the design of the cathode pad readout plane. The design parameters of the TRD readout pad plane are introduced and analysed regarding their physical properties. The noise patterns observed in the detector can be directly linked to the static pad capacitance distribution and corrected for it. A summary is then given of the TRD services infrastructure at CERN: a 70 kW low voltage system, a 1080 channel 2.5 kV high voltage setup and the Ethernet network serving more than 600 nodes. Two beam tests were conducted at the CERN PS accelerator in 2004 and 2007 using full sized TRD chambers from series production. Details on the setups are presented with particular emphasis on the custom tailored data acquisition systems. Finally the performance of the TRD is studied, focusing on the pion rejection capability and the excellent position resolution. (orig.)

  16. Technique of absolute efficiency determination for gamma radiation semiconductor detectors

    International Nuclear Information System (INIS)

    Simple technique is suggested to determine the absolute efficiency (E) of semiconductor detectors (SCD) which employes low-intensity neutron sources wide spread in scientific laboratories. The technique is based on using radioactive nuclide gamma radiation in decay chains of heavy element fission fragments, uranium-235, for example. Cumulative yields of a number of nulcides following heavy element fission are measured to a high accuracy (1-5%), which permits to . the value E is determined for a wide energy range (from X- ray to some MeV); using a nuclide with a well known decay scheme and measured to a high accuracy cumulative yield 140La, for example, one can calibrate in absolute values comparatively easily obtained plots of the SCD relative efficiency. The technique allows to determine the E value for extended plane (and volumetric) sources of an arbitrary form. Some nuclides, convenient for the determination of E, and their nuclear characteristics are tabulated

  17. Personal Radiation Detector Field Test and Evaluation Campaign

    International Nuclear Information System (INIS)

    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

  18. Advances in Physical and Biological Radiation Detectors. Proceedings of a Symposium on New Developments in Physical and Biological Radiation Detectors

    International Nuclear Information System (INIS)

    Radiation dosimetry is a fundamental part of all radiation protection work. The measurements are made with a variety of instruments, and health physicists, after professional interpretation of the data, can assess the levels of exposure which might be encountered in a given area or the individual doses received by workers, visitors and others at places where the possibility of radiation exposure exists. The types of radiation concerned here are photon radiations, ranging from soft X-rays to gamma rays, and particulate radiations such as β-rays, α-particles, protons, neutrons and fission fragments. The type of technique used depends not only on the type of radiation but also on such factors as whether the radiation is from a source internal or external to the body. Radiation dosimetry is not only used at nuclear facilities; it has diverse applications, for example in determining doses when radiation sources are employed for medical diagnostics and therapy, in safeguarding workers in any industry where isotopes are used, and in assessing the effect of both naturally occurring and man-made radiations on the general public and the environment. The advances of modern technology have increased the variety of sources; an example can be given from colour television, where the high potential necessary in certain colour cathode-ray tubes generates a non-negligible amount of X-rays. The Symposium on New Developments in Physical and Biological Radiation Detectors was one of a continuing series of meetings in which the International Atomic Energy Agency furthers the exchange of information on all aspects of personnel and area dosimetry. The Symposium was devoted in particular to a study of the dose meters themselves - their radiation-sensitive elements (both physical and biological),their instrumentation, and calibration and standardization. Several speakers suggested that the situation in the standardization and calibration of measuring equipment and sources was

  19. Two-dimension multiwire detector for ionizing radiation

    International Nuclear Information System (INIS)

    A multiwire proportional Counter of 100 x 100 mm2 sensitive area has been developed. The chamber is formed by three planes: a cathode plane of 50 μm gold coated tungsten wires stretched on an Epoxi frame; and anode plane made of 20 μm gold plated tungsten wires stretched at 45 deg C with respect to the first cathode wires; and second cathode plane made of copper strips on a printed circuit board at 90 deg C with respect to the first cathode. The cathode strips are connected to the taps of delay-lines chips. The position of the incidence of radiation is extracted by measuring the time difference of the pulse arriving at the extremities of the delay-line chain for each coordinate. The performance of the detector has been tested using 5.89 KeV X-rays from a 55 Fe source, and 8.04 KeV from Rigaku X-rays generator, operating the detector with 90% Ar + 10% CH4 gas mixture at 930 mbar. An energy resolution of 26% was obtained. An integral non linearity better than 0.3% and a position resolution better than 1 mm have been observed. The information corresponding to each one of the coordinates were digitized by a TDC in a CAMAC system and stored event by event in a micro-computer (IBM-AT). (author)

  20. Radiation Detector Characterization at APO While Stacking pbars in 1999

    International Nuclear Information System (INIS)

    The Main Injector provided beam for pbar stacking for the first time in 1999 over the period 12/20 to 12/21. The purpose of this memo is to record some observations on the response of various radiation detectors as a function of beam on the pbar targel. The detectors include a Scarecrow in the APO Vault, a Chipmunk just upstream of the APO vault, and a Chipmunk in the water cage adjacent to the Pulsed Magnet pump skid in the water systems cage. In addition, there are air monitors, one sampling in the PreVault enclosure and one sampling at the exhaust stack at the upstream end of lhe PreTarget enclosure. All data was collected by the ACNET system Lumberjack data logger. Beam intensity data was summed over consecutive 10 minute periods and normalized to an hourly intensity. The Chipmunk, Scarecrow, and Air Monitor data are based 10 minute averages taken over periods which coincide with normalized beam intensity.

  1. Chemical applications of synchrotron radiation: Workshop report

    International Nuclear Information System (INIS)

    The most recent in a series of topical meetings for Advanced Photon Source user subgroups, the Workshop on Chemical Applications of Synchrotron Radiation (held at Argonne National Laboratory, October 3-4, 1988) dealt with surfaces and kinetics, spectroscopy, small-angle scattering, diffraction, and topography and imaging. The primary objectives were to provide an educational resource for the chemistry community on the scientific research being conducted at existing synchrotron sources and to indicate some of the unique opportunities that will be made available with the Advanced Photon Source. The workshop organizers were also interested in gauging the interest of chemists in the field of synchrotron radiation. Interest expressed at the meeting has led to initial steps toward formation of a Chemistry Users Group at the APS. Individual projects are processed separately for the data bases

  2. Chemical applications of synchrotron radiation: Workshop report

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

    The most recent in a series of topical meetings for Advanced Photon Source user subgroups, the Workshop on Chemical Applications of Synchrotron Radiation (held at Argonne National Laboratory, October 3-4, 1988) dealt with surfaces and kinetics, spectroscopy, small-angle scattering, diffraction, and topography and imaging. The primary objectives were to provide an educational resource for the chemistry community on the scientific research being conducted at existing synchrotron sources and to indicate some of the unique opportunities that will be made available with the Advanced Photon Source. The workshop organizers were also interested in gauging the interest of chemists in the field of synchrotron radiation. Interest expressed at the meeting has led to initial steps toward formation of a Chemistry Users Group at the APS. Individual projects are processed separately for the data bases.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hull, E.L. [PHDS Corporation, 3011 Amherst Road, Knoxville, TN 37921 (United States); Jackson, E.G.; Lister, C.J. [Physics Department, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Pehl, R.H. [PHDS Corporation, 3011 Amherst Road, Knoxville, TN 37921 (United States)

    2014-10-21

    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 ∼8×10{sup 9} n/cm{sup 2}. The radiation-damaged detectors were studied in the 60–80 K temperature range.

  4. Radiation detector device for rejecting and excluding incomplete charge collection events

    Science.gov (United States)

    Bolotnikov, Aleksey E.; De Geronimo, Gianluigi; Vernon, Emerson; Yang, Ge; Camarda, Giuseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B.

    2016-05-10

    A radiation detector device is provided that is capable of distinguishing between full charge collection (FCC) events and incomplete charge collection (ICC) events based upon a correlation value comparison algorithm that compares correlation values calculated for individually sensed radiation detection events with a calibrated FCC event correlation function. The calibrated FCC event correlation function serves as a reference curve utilized by a correlation value comparison algorithm to determine whether a sensed radiation detection event fits the profile of the FCC event correlation function within the noise tolerances of the radiation detector device. If the radiation detection event is determined to be an ICC event, then the spectrum for the ICC event is rejected and excluded from inclusion in the radiation detector device spectral analyses. The radiation detector device also can calculate a performance factor to determine the efficacy of distinguishing between FCC and ICC events.

  5. Performance characteristics of a silicon photomultiplier based compact radiation detector for Homeland Security applications

    International Nuclear Information System (INIS)

    A next-generation compact radiation detector was studied for more accurate measurement of radiation and for improvement of detector reliability for the purpose of developing radiation protection technology and military applications. The previously used radiation detector had some limitations due to its bulky size, limited range and its environment for radiation measurement. On the other hand, the compact radiation detector examined in this study utilizes a silicon photomultiplier which appears to be more suitable for this application because of its physical superiority characterized by its small size, high sensitivity, and durability. Accordingly, a SiPM based scintillation detector has been developed as part of this basic study of military radiation detectors. The detector has been tested for its ability to obtain the operating characteristics of a sensor and analyzed with variations of parameter values and for efficiency of detection in accordance with its ability to measure radiation in the environment. Two SiPM based Scintillation detectors with LYSO, BGO and CsI:Tl scintillators were developed and the detectors were analyzed by a number of operating characteristics such as reverse bias, operating temperature and high magnetic field, that depend on environmental changes in radiation measurement. The Photon count rate and spectra were compared for these three scintillators. We found that there were variations in the radiation detection which were characterized by reverse bias, temperature and high magnetic field. It was also found that there was an 11.9% energy resolution for the LYSO, 15.5% for BGO and 13.5% for CsI:Tl using Array SiPM, and 18% for CsI:Tl energy resolution using single SiPM when we measured energy resolution of 511 keV for 22Na. These results demonstrate the potential widespread use of SiPM based compact radiation detectors for Homeland Security applications

  6. Design of a Silicon Photomultiplier Based Compact Radiation Detector for Homeland Security Screening

    International Nuclear Information System (INIS)

    Next-generation compact radiation detector was studied for more accurate measurement of radiation and improvement of reliability of the detector with purpose of developing of radiation protection technology and military application. The radiation detector which was used previously had some limitations due to the bulky size, limited range and the environment of radiation measurement. On the other hand, the compact radiation detector under this study which has adopted the silicon photomultiplier seems to be suitable for the application because of its physical excellence which are characterized by its small size, high sensitivity and durability. Accordingly, a SiPM based Scintillation detector has been made as a part of basic study of military radiation detector development. The detector has been tested for obtaining the operating characteristics of a sensor and analyzed with variation of parameter values and the efficiency of detection in accordance with the factor of measurement environment of radiation. The two SiPM based Scintillation detectors with the LYSO, BGO and CsI:Tl scintillator were made and the detectors were analyzed with the variation of operating characteristics as reverse bias, operating temperature and high magnetic field that are depend on environmental changes of radiation measurement. The results of three scintillators for a photon count rate and spectra were compared with each other. It was found that there are variations of radiation detection which are characterized by reverse bias, temperature and high magnetic field. Also, It was found that there were the 11.9 % for the LYSO, 15.5 % for BGO and 13.5 % for CsI:Tl energy resolution using array SiPM, and 18 % for CsI:Tl energy resolution using single SiPM, respectively when we measured energy resolution of 511 keV for 22Na. The results demonstrate the potential of SiPM based compact radiation detector to be used widely for Homeland Security applications. (authors)

  7. Performance characteristics of a silicon photomultiplier based compact radiation detector for Homeland Security applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye Min, E-mail: ramilab2011@gmail.com; Joo, Koan Sik

    2015-05-01

    A next-generation compact radiation detector was studied for more accurate measurement of radiation and for improvement of detector reliability for the purpose of developing radiation protection technology and military applications. The previously used radiation detector had some limitations due to its bulky size, limited range and its environment for radiation measurement. On the other hand, the compact radiation detector examined in this study utilizes a silicon photomultiplier which appears to be more suitable for this application because of its physical superiority characterized by its small size, high sensitivity, and durability. Accordingly, a SiPM based scintillation detector has been developed as part of this basic study of military radiation detectors. The detector has been tested for its ability to obtain the operating characteristics of a sensor and analyzed with variations of parameter values and for efficiency of detection in accordance with its ability to measure radiation in the environment. Two SiPM based Scintillation detectors with LYSO, BGO and CsI:Tl scintillators were developed and the detectors were analyzed by a number of operating characteristics such as reverse bias, operating temperature and high magnetic field, that depend on environmental changes in radiation measurement. The Photon count rate and spectra were compared for these three scintillators. We found that there were variations in the radiation detection which were characterized by reverse bias, temperature and high magnetic field. It was also found that there was an 11.9% energy resolution for the LYSO, 15.5% for BGO and 13.5% for CsI:Tl using Array SiPM, and 18% for CsI:Tl energy resolution using single SiPM when we measured energy resolution of 511 keV for {sup 22}Na. These results demonstrate the potential widespread use of SiPM based compact radiation detectors for Homeland Security applications.

  8. Two-dimension multiwire detector for ionizing radiation; Detector multifilar bidimensional para radiacao ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Barberino, Carlos Henrique

    1993-12-31

    A multiwire proportional Counter of 100 x 100 mm{sup 2} sensitive area has been developed. The chamber is formed by three planes: a cathode plane of 50 {mu}m gold coated tungsten wires stretched on an Epoxi frame; and anode plane made of 20 {mu}m gold plated tungsten wires stretched at 45 deg C with respect to the first cathode wires; and second cathode plane made of copper strips on a printed circuit board at 90 deg C with respect to the first cathode. The cathode strips are connected to the taps of delay-lines chips. The position of the incidence of radiation is extracted by measuring the time difference of the pulse arriving at the extremities of the delay-line chain for each coordinate. The performance of the detector has been tested using 5.89 KeV X-rays from a {sup 55} Fe source, and 8.04 KeV from Rigaku X-rays generator, operating the detector with 90% Ar + 10% CH{sub 4} gas mixture at 930 mbar. An energy resolution of 26% was obtained. An integral non linearity better than 0.3% and a position resolution better than 1 mm have been observed. The information corresponding to each one of the coordinates were digitized by a TDC in a CAMAC system and stored event by event in a micro-computer (IBM-AT). (author) 56 refs., 68 figs.

  9. Radiation detection. Chapter 4. Effects of tellurium precipitates on charge collection in CZT (CdZnTe) nuclear radiation detectors

    International Nuclear Information System (INIS)

    It has been recently demonstrated that individual Tellurium (Te) precipitates identified with infrared (IR) transmission microscopes in radiation detector-grade CdZnTe (CZT) crystals correlate precisely with poor charge collection. This indicates that Te precipitates adversely affect the electron charge collection efficiency and thus the performance of nuclear radiation detectors produced from the crystals. By employing different techniques it is investigated how Te precipitates affect different CZT devices. These measurements indicate that Te precipitates put limits on the size, electrode configurations and spectral performance of CZT detectors. These limits can be relaxed by lowering the size and density of Te precipitates in the detectors

  10. Novel computational methods for image analysis and quantification using position sensitive radiation detectors

    OpenAIRE

    Sanchez Crespo, Alejandro

    2005-01-01

    The major advantage of position sensitive radiation detector systems lies in their ability to non invasively map the regional distribution of the emitted radiation in real-time. Three of such detector systems were studied in this thesis, gamma-cameras, positron cameras and CMOS image sensors. A number of physical factors associated to these detectors degrade the qualitative and quantitative properties of the obtained images. These blurring factors could be divided into two groups. The first g...

  11. Some recent results of the silicon detector radiation damage study by the RD2 collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Anghinolfi, F. [CERN, Geneva (Switzerland); Bates, S. [CERN, Geneva (Switzerland); Bardos, R. [School of Physics, University of Melbourne, Parkville, Victoria 3052 (Australia); Bonino, R. [DPNC, Geneva University, Geneva (Switzerland); Chilingarov, A. [CERN, Geneva (Switzerland); Clark, A.G. [DPNC, Geneva University, Geneva (Switzerland); Feick, H. [1. Institut fuer Experimentalphysik, Universitaet Hamburg, D-20355 Hamburg (Germany); Fretwurst, E. [1. Institut fuer Experimentalphysik, Universitaet Hamburg, D-20355 Hamburg (Germany); Glaser, M. [CERN, Geneva (Switzerland); Gorfine, G. [School of Physics, University of Melbourne, Parkville, Victoria 3052 (Australia); Goessling, C. [Institut fuer Physik, Universitaet Dortmund, D-4600 Dortmund (Germany); Jarron, P. [CERN, Geneva (Switzerland); Kambara, H. [DPNC, Geneva University, Geneva (Switzerland); Lindstroem, G. [1. Institut fuer Experimentalphysik, Universitaet Hamburg, D-20355 Hamburg (Germany); Lisowski, B. [Institut fuer Physik, Universitaet Dortmund, D-4600 Dortmund (Germany); Moorhead, G.F. [School of Physics, University of Melbourne, Parkville, Victoria 3052 (Australia); Munday, D.J. [Cambridge Univ. (United Kingdom). Cavendish Lab.; Parker, M.A. [Cambridge Univ. (United Kingdom). Cavendish Lab.; Perrin, E. [DPNC, Geneva University, Geneva (Switzerland); Pilath, S. [Institut fuer Physik, Universitaet Dortmund, D-4600 Dortmund (Germany); Rolf, A. [Institut fuer Physik, Universitaet Dortmund, D-4600 Dortmund (Germany); Schulz, T. [1. Institut fuer Experimentalphysik, Universitaet Hamburg, D-20355 Hamburg (Germany); Taylor, G.N. [School of Physics, University of Melbourne, Parkville, Victoria 3052 (Australia); Teiger, J. [Centre d`Etudes Nucleaires de Saclay, F-91191 Gif-sur-Yvette (France); Tovey, S.N. [School of Physics, University of Melbourne, Parkville, Victoria 3052 (Australia); Uhlmann, T.M. [1. Institut fuer Experimentalphysik, Universitaet Hamburg, D-20355 Hamburg (Germany)

    1995-06-01

    Recent results by the RD2 Collaboration of a study of radiation damage of silicon detectors for the ATLAS detector at LHC are presented. The detectors have been irradiated by neutrons with fluences of up to 1.5x10{sup 14} neutrons/cm{sup 2}. The electric field in the detectors before and after type inversion, the depletion voltage and the dark current were studied. (orig.).

  12. Industrial workshop on LASL semiconductor radiation-detector research and development

    International Nuclear Information System (INIS)

    An Industrial Workshop on LASL Semiconductor Radiation Detector Research and Development was held at the Los Alamos Scientific Laboratory (LASL) in the spring of 1977. The purpose was to initiate communication between our detector research and development program and industry. LASL research programs were discussed with special emphasis on detector problems. Industrial needs and capabilities in detector research and development were also presented. Questions of technology transfer were addressed. The notes presented here are meant to be informal, as were the presentations

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

    Science.gov (United States)

    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.

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

    CERN Document Server

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

    2011-01-01

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

  15. Performance of an LPD prototype detector at MHz frame rates under Synchrotron and FEL radiation

    Science.gov (United States)

    Koch, A.; Hart, M.; Nicholls, T.; Angelsen, C.; Coughlan, J.; French, M.; Hauf, S.; Kuster, M.; Sztuk-Dambietz, J.; Turcato, M.; Carini, G. A.; Chollet, M.; Herrmann, S. C.; Lemke, H. T.; Nelson, S.; Song, S.; Weaver, M.; Zhu, D.; Meents, A.; Fischer, P.

    2013-11-01

    A MHz frame rate X-ray area detector (LPD — Large Pixel Detector) is under development by the Rutherford Appleton Laboratory for the European XFEL. The detector will have 1 million pixels and allows analogue storage of 512 images taken at 4.5 MHz in the detector front end. The LPD detector has 500 μm thick silicon sensor tiles that are bump bonded to a readout ASIC. The ASIC's preamplifier provides relatively low noise at high speed which results in a high dynamic range of 105 photons over an energy range of 5-20 keV. Small scale prototypes of 32 × 256 pixels (LPD 2-Tile detector) and 256 × 256 pixels (LPD supermodule detector) are now available for X-ray tests. The performance of prototypes of the detector is reported for first tests under synchrotron radiation (PETRA III at DESY) and Free-Electron-Laser radiation (LCLS at SLAC). The initial performance of the detector in terms of signal range and noise, radiation hardness and spatial and temporal response are reported. The main result is that the 4.5 MHz sampling detection chain is reliably working, including the analogue on-chip memory concept. The detector is at least radiation hard up to 5 MGy at 12 keV. In addition the multiple gain concept has been demonstrated over a dynamic range to 104 at 12 keV with a readout noise equivalent to < 1 photon rms in its most sensitive mode.

  16. Radiation induced polarization in CdTe detectors

    Science.gov (United States)

    Vartsky, D.; Goldberg, M.; Eisen, Y.; Shamai, Y.; Dukhan, R.; Siffert, P.; Koebel, J. M.; Regal, R.; Gerber, J.

    1988-01-01

    Polarization induced by irradiation with intense gamma ray sources has been studied in chlorine-compensated CdTe detectors. The influence of several parameters, such as applied field strength, temperature and incident photon flux, on the polarization effect have been investigated. A relationship was found between the degree of polarization, detector efficiency and detector leakage current.

  17. Radiation induced polarization in CdTe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vartsky, D.; Goldberg, M.; Eisen, Y.; Shamai, Y.; Dukhan, R.; Siffert, P.; Koebel, J.M.; Regal, R.; Gerber, J.

    1988-01-15

    Polarization induced by irradiation with intense gamma ray sources has been studied in chlorine-compensated CdTe detectors. The influence of several parameters, such as applied field strength, temperature and incident photon flux, on the polarization effect have been investigated. A relationship was found between the degree of polarization, detector efficiency and detector leakage current.

  18. Temperature dependence of radiation damage and its annealing in silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, H.J.; Boissevain, J.G.; Holzscheiter, K.; Kapustinsky, J.S.; Palounek, A.P.T.; Sondheim, W.E. [Los Alamos National Lab., NM (United States); Barberis, E.; Cartiglia, N.; Leslie, J.; Pitzl, D.; Rowe, W.A.; Sadrozinski, H.F.W.; Seiden, A.; Spencer, E.; Wilder, M. [California Univ., Santa Cruz, CA (United States). Inst. for Particle Physics; Ellison, J.A.; Fleming, J.K.; Jerger, S.; Joyce, D.; Lietzke, C.; Reed, E.; Wimpenny, S.J. [California Univ., Riverside, CA (United States); Ferguson, P. [Missouri Univ., Rolla, MO (United States); Frautschi, M.A.; Matthews, J.A.J.; Skinner, D. [New Mexico Univ., Albuquerque, NM (United States)

    1992-12-01

    The radiation damage resulting from the large particle fluences predicted at the Superconducting Super Collider will induce significant leakage currents in silicon detectors. In order to limit those currents, we plan to operate the detectors at reduced temperatures ({approximately}0{degree} C). In this paper, we present the results of a study of temperature effects on both the initial radiation damage and the long-term annealing of that damage in silicon PIN detectors. Depletion voltage results are reported. The detectors were exposed to approximately 10{sup 14}/cm{sup 2} 650 MeV protons. Very pronounced temperature dependencies were observed.

  19. Temperature dependence of radiation damage and its annealing in silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, H.J.; Boissevain, J.G.; Holzscheiter, K.; Kapustinsky, J.S.; Palounek, A.P.T.; Sondheim, W.E. (Los Alamos National Lab., NM (United States)); Barberis, E.; Cartiglia, N.; Leslie, J.; Pitzl, D.; Rowe, W.A.; Sadrozinski, H.F.W.; Seiden, A.; Spencer, E.; Wilder, M. (Univ. of California, Santa Cruz, CA (United States). Santa Cruz Inst. for Particle Physics); Ellison, J.A.; Fleming, J.K.; Jerger, S.; Joyce, D.; Lietzke, C.; Reed, E.; Wimpenny, S.J. (Univ. of California, Riverside, CA (United States)); Ferguson, P. (Univ. of Missouri, Rolla, MO (United States)); Frautschi, M.A.; Matthews, J.A.J.; Skinner, D. (Univ. of New Mexico, Albuquerque, NM (United States))

    1993-08-01

    The radiation damage resulting from the large particle fluences predicted at the Superconducting Super Collider will induce significant leakage currents in silicon detectors. In order to limit those currents, the authors plan to operate the detectors at reduced temperatures ([approximately] 0 C). In this paper, they present the results of a study of temperature effects on both the initial radiation damage and the long-term annealing of that damage in silicon PIN detectors. Depletion voltage results are reported. The detectors were exposed to approximately 10[sup 14]/cm[sup 2] 650 MeV protons. Very pronounced temperature dependencies were observed.

  20. Temperature dependence of radiation damage and its annealing in silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, H.J.; Boissevain, J.G.; Holzscheiter, K.; Kapustinsky, J.S.; Palounek, A.P.T.; Sondheim, W.E. (Los Alamos National Lab., NM (United States)); Barberis, E.; Cartiglia, N.; Leslie, J.; Pitzl, D.; Rowe, W.A.; Sadrozinski, H.F.W.; Seiden, A.; Spencer, E.; Wilder, M. (California Univ., Santa Cruz, CA (United States). Inst. for Particle Physics); Ellison, J.A.; Fleming, J.K.; Jerger, S.; Joyce, D.; Lietzke, C.; Re

    1992-01-01

    The radiation damage resulting from the large particle fluences predicted at the Superconducting Super Collider will induce significant leakage currents in silicon detectors. In order to limit those currents, we plan to operate the detectors at reduced temperatures ([approximately]0[degree] C). In this paper, we present the results of a study of temperature effects on both the initial radiation damage and the long-term annealing of that damage in silicon PIN detectors. Depletion voltage results are reported. The detectors were exposed to approximately 10[sup 14]/cm[sup 2] 650 MeV protons. Very pronounced temperature dependencies were observed.

  1. Plasma Processes : Plasma sprayed alumina coatings for radiation detector development

    Indian Academy of Sciences (India)

    Mary Alex; V Balagi; K R Prasad; K P Sreekumar; P V Ananthapadmanabhan

    2000-11-01

    Conventional design of radiation detectors uses sintered ceramic insulating modules. The major drawback of these ceramic components is their inherent brittleness. Ion chambers, in which these ceramic spacers are replaced by metallic components with plasma spray coated alumina, have been developed in our Research Centre. These components act as thin spacers that have good mechanical strength as well as high electrical insulation and replace alumina insulators with the same dimensions. As a result, the design of the beam loss monitor ion chamber for CAT could be simplified by coating the outer surface of the HT electrode with alumina. One of the chambers developed for isotope calibrator for brachytherapy gamma sources has its outer aluminium electrode (60 mm dia × 220 mm long) coated with 250 thick alumina (97%) + titania (3%). In view of potential applications in neutron-sensitive ion chambers used in reactor control instrumentation, studies were carried out on alumina 100 to 500 thick coatings on copper, aluminium and SS components. The electrical insulation varied from 108 ohms to 1012 ohms for coating thicknesses above 200 . The porosity in the coating resulted in some fall in electrical insulation due to moisture absorption. An improvement could be achieved by providing the ceramic surface with moisture-repellent silicone oil coating. Irradiation at Apsara reactor core location showed that the coating on aluminium was found to be unaffected after exposure to 1017 nvt fluence.

  2. Radiation monitoring and beam dump system of the OPAL silicon microvertex detector

    CERN Document Server

    Braibant, S

    1997-01-01

    The OPAL microvertex silicon detector radiation monitoring and beam dump system is described. This system was designed and implemented in order to measure the radiation dose received at every beam crossing and to induce a fast beam dump if the radiation dose exceeds a given threshold.

  3. Influence of radiation induced defect clusters on silicon particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Junkes, Alexandra

    2011-10-15

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) addresses some of today's most fundamental questions of particle physics, like the existence of the Higgs boson and supersymmetry. Two large general-purpose experiments (ATLAS, CMS) are installed to detect the products of high energy protonproton and nucleon-nucleon collisions. Silicon detectors are largely employed in the innermost region, the tracking area of the experiments. The proven technology and large scale availability make them the favorite choice. Within the framework of the LHC upgrade to the high-luminosity LHC, the luminosity will be increased to L=10{sup 35} cm{sup -2}s{sup -1}. In particular the pixel sensors in the innermost layers of the silicon trackers will be exposed to an extremely intense radiation field of mainly hadronic particles with fluences of up to {phi}{sub eq}=10{sup 16} cm{sup -2}. The radiation induced bulk damage in silicon sensors will lead to a severe degradation of the performance during their operational time. This work focusses on the improvement of the radiation tolerance of silicon materials (Float Zone, Magnetic Czochralski, epitaxial silicon) based on the evaluation of radiation induced defects in the silicon lattice using the Deep Level Transient Spectroscopy and the Thermally Stimulated Current methods. It reveals the outstanding role of extended defects (clusters) on the degradation of sensor properties after hadron irradiation in contrast to previous works that treated effects as caused by point defects. It has been found that two cluster related defects are responsible for the main generation of leakage current, the E5 defects with a level in the band gap at E{sub C}-0.460 eV and E205a at E{sub C}-0.395 eV where E{sub C} is the energy of the edge of the conduction band. The E5 defect can be assigned to the tri-vacancy (V{sub 3}) defect. Furthermore, isochronal annealing experiments have shown that the V{sub 3} defect

  4. Influence of radiation induced defect clusters on silicon particle detectors

    International Nuclear Information System (INIS)

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) addresses some of today's most fundamental questions of particle physics, like the existence of the Higgs boson and supersymmetry. Two large general-purpose experiments (ATLAS, CMS) are installed to detect the products of high energy protonproton and nucleon-nucleon collisions. Silicon detectors are largely employed in the innermost region, the tracking area of the experiments. The proven technology and large scale availability make them the favorite choice. Within the framework of the LHC upgrade to the high-luminosity LHC, the luminosity will be increased to L=1035 cm-2s-1. In particular the pixel sensors in the innermost layers of the silicon trackers will be exposed to an extremely intense radiation field of mainly hadronic particles with fluences of up to Φeq=1016 cm-2. The radiation induced bulk damage in silicon sensors will lead to a severe degradation of the performance during their operational time. This work focusses on the improvement of the radiation tolerance of silicon materials (Float Zone, Magnetic Czochralski, epitaxial silicon) based on the evaluation of radiation induced defects in the silicon lattice using the Deep Level Transient Spectroscopy and the Thermally Stimulated Current methods. It reveals the outstanding role of extended defects (clusters) on the degradation of sensor properties after hadron irradiation in contrast to previous works that treated effects as caused by point defects. It has been found that two cluster related defects are responsible for the main generation of leakage current, the E5 defects with a level in the band gap at EC-0.460 eV and E205a at EC-0.395 eV where EC is the energy of the edge of the conduction band. The E5 defect can be assigned to the tri-vacancy (V3) defect. Furthermore, isochronal annealing experiments have shown that the V3 defect exhibits a bistability, as does the leakage current. In oxygen rich material the

  5. Chemical effects of ionizing radiation and sonic energy in the context of chemical evolution

    International Nuclear Information System (INIS)

    Ionizing radiation and sonic energy are considered as sources for chemical evolution processes. These sources have still a modest place in the interdisciplinary approach for the prebiological synthesis of organic compounds. Studies in Radiation Chemistry and Sonochemistry can provide a deeper insight into the chemical processes that may have importance for prebiotic chemistry. The present work concerns the analysis of some chemical reactions induced by ionizing radiation or cavitation in aqueous media that may be relevant to chemical evolution studies. (author)

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

    Science.gov (United States)

    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.

  7. Asymmetric devices based on carbon nanotubes as detectors of sub-THz radiation

    Science.gov (United States)

    Gayduchenko, I. A.; Fedorov, G. E.; Stepanova, T. S.; Titova, N.; Voronov, B. M.; But, D.; Coquillat, D.; Diakonova, N.; Knap, W.; Goltsman, G. N.

    2016-08-01

    Demand for efficient terahertz (THz) radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. In this work, we systematically investigate the response of asymmetric carbon nanodevices to sub-terahertz radiation using different sensing elements: from dense carbon nanotube (CNT) network to individual CNT. We conclude that the detectors based on individual CNTs both semiconducting and quasi-metallic demonstrate much stronger response in sub-THz region than detectors based on disordered CNT networks at room temperature. We also demonstrate the possibility of using asymmetric detectors based on CNT for imaging in the THz range at room temperature. Further optimization of the device configuration may result in appearance of novel terahertz radiation detectors.

  8. Performance And Radiation Hardness Of The Atlas/sct Detector Module

    CERN Document Server

    Eklund, L

    2003-01-01

    The ATLAS experiment is a general purpose experiment being constructed at the Large Hadron Collider (LHC) at FERN, Geneva. ATLAS is designed to exploit the full physics potential of LHC, in particular to study topics concerning the Higgs mechanism, Super-symmetry and CP violation. The cross sections for the processes under study are extremely small, requiring very high luminosity colliding beams. The Semiconductor Tracker (SCT) is an essential part of the Inner Detector tracking system of ATLAS. The active elements of the SCT is 4088 detector modules, tiled on four barrel cylinders and eighteen endcap disks. As a consequence of the high luminosity, the detector modules will operate in a harsh radiation environment. This thesis describes work concerning radiation hardness, beam test performance and methods for production testing of detector modules. The radiation hardness studies have been focused on the electrical performance of the front-end ASIC and the detector module. The results have identified features ...

  9. Ion Beam Induced Charge Collection (IBICC) Studies of Cadmium Zinc Telluride (CZT) Radiation Detectors

    International Nuclear Information System (INIS)

    Cadmium Zinc Telluride is an emerging material for room temperature radiation detectors. In order to optimize the performance of these detectors, it is important to determine how the electronic properties of CZT are related to the presence of impurities and defects that are introduced during the crystal growth and detector fabrication. At the Sandia microbeam facility IBICC and Time Resolved IBICC (TRIBICC) were used to image electronic properties of various CZT detectors. Two-dimensional areal maps of charge collection efficiency were deduced from the measurements. In order to determine radiation damage to the detectors, we measured the deterioration of the IBICC signal as the function of dose. A model to explain quantitatively the pattern observed in the charge collection efficiency maps of the damaged detectors has been developed and will be discussed in the paper

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Novel radiation hard microfabricated scintillation detectors with high spatial resolution

    CERN Document Server

    Mapelli, A; Haguenauerc, M; Jiguet, S; Vico Triviño, N; Renaud, P

    2010-01-01

    A novel liquid scintillation detector with high spatial resolution is being developed with standard microfabrication techniques. It consists of a dense array of scintillating waveguides obtained by filling microfluidic channels with an organic liquid scintillator and optically coupled to a pixellated photodetector. Such a microfluidic device can be designed and processed to meet the requirements of a wide range of applications like medical imaging, homeland security and high-energy physics. High-spatial resolution miniaturized detectors as well as large-area detectors can easily be fabricated. The fabrication process of a prototype detector and experimental results are presented in this paper.

  12. Radiation tolerance studies of neutron irradiated double sided silicon microstrip detectors

    Science.gov (United States)

    Singla, M.; Larionov, P.; Balog, T.; Heuser, J.; Malygina, H.; Momot, I.; Sorokin, I.; Sturm, C.

    2016-07-01

    Radiation tolerance studies were made on double-sided silicon microstrip detectors for the Silicon Tracking System of the Compressed Baryonic Matter experiment at FAIR. The prototype detectors from two different vendors were irradiated to twice the highest expected fluence (1 ×1014 1 MeVneqcm-2) in the CBM experimental runs of several years. Test results from these prototype detectors both before and after irradiations have been discussed.

  13. Uncooled Radiation Hard SiC Schottky VUV Detectors Capable of Single Photon Sensing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project seeks to design, fabricate, characterize and commercialize very large area, uncooled and radiative hard 4H-SiC VUV detectors capable of near single...

  14. Recent trends of X-ray detectors in synchrotron radiation science

    CERN Document Server

    Suzuki, M

    2003-01-01

    This article attempts to describe the recent trends of X-ray detectors in synchrotron radiation science in the light of not only the advance but also the stagnation of which are seriously dependent upon the current semiconductor technology. (author)

  15. Thermal Characterization of Absorbing Coatings for Thermal Detectors of Radiation by Photopyroelectric Method

    OpenAIRE

    Bravina, Svetlana L.; Morozovsky, Nicholas V.; Dovbeshko, Galina I.; Obraztsova, Elena D.

    2006-01-01

    By photothermomodulatoin method the comparative study of thermal diffusivity of absorbing coating for sensitive elements of pyroelectric detectors of radiation formed from metal dispersion layer blacks, dielectric paint blacks and carbon nanotubes paint blacks has been performed. Prospects of using carbon nanotubes based black absorbing coatings for pyroelectric and other thermal detector application are shown.

  16. One-dimensional ionizing radiation detector on the charge-coupled device basis

    International Nuclear Information System (INIS)

    Basic features of the one-dimensional ionizing radiation detector designed on the charge-coupled device (CCD) basis with surface as well as deepened channel are studied. The eta (E) dependence of the detector quantum efficiency on the density of soft X radiation energy is given. It has been found on the basis of the analysis of the eta(E) dependence that the most acceptable range of using CCD-detectors lies in the limits of radiation energy from 2 to 12 keV. In this energy region the linearity of ionizing radiation flux conversion into electrical charge is assured. The CCD-detector sensitivity constitutes 2x108 photon/(cm2xs). The upper limit of the detector dynamic range equals to 1010 photon/(cm2xs) while the whole dynamic range equals to 50. The effect of long-term irradiation on the basic features of the CCD-detectors is considered as well as restoration methods of their operating performances are proposed. The real irradiation levels, which the CCD-detectors made on the n-Si base withstand, constitute (1-3)x104 rad. It is pointed out that most prospective CCD-detectors are those with a deepened channel and Schottky gates in which control through the oxide layer is missing

  17. Performance of an LPD prototype detector at MHz frame rates under Synchrotron and FEL radiation

    CERN Document Server

    Koch, Andreas; Nicholls, Tim; Angelsen, Christian; Coughlan, John; French, Marcus; Hauf, Steffen; Kuster, Markus; Sztuk-Dambietz, Jolanta; Turcato, Monica; Carini, Gabriella A; Chollet, Matthieu; Herrmann, Sven C; Lemke, Henrik T; Nelson, Silke; Song, Sanghoon; Weaver, Matt; Zhu, Diling; Meents, Alke; Fischer, Pontus

    2013-01-01

    A MHz frame rate X-ray area detector (LPD - Large Pixel Detector) is under development by the Rutherford Appleton Laboratory for the European XFEL. The detector will have 1 million pixels and allows analogue storage of 512 images taken at 4.5 MHz in the detector front end. The LPD detector has 500 mm thick silicon sensor tiles that are bump bonded to a readout ASIC. The ASICs preamplifier provides relatively low noise at high speed which results in a high dynamic range of 10^5 photons over an energy range of 5-20 keV. Small scale prototypes of 32x256 pixels (LPD 2-Tile detector) and 256x256 pixels (LPD supermodule detector) are now available for X-ray tests. The performance of prototypes of the detector is reported for first tests under synchrotron radiation (PETRA III at DESY) and Free-Electron-Laser radiation (LCLS at SLAC). The initial performance of the detector in terms of signal range and noise, radiation hardness and spatial and temporal response are reported. The main result is that the 4.5 MHz sampli...

  18. The iQID camera: An ionizing-radiation quantum imaging detector

    OpenAIRE

    Miller, Brian W.; Gregory, Stephanie J.; Fuller, Erin S.; Barrett, Harrison H.; Barber, H. Bradford; Furenlid, Lars R.

    2014-01-01

    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...

  19. Assessment of radiation exposure of nuclear medicine staff using personal TLD dosimeters and charcoal detectors

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, F.; Garcia-Talavera, M.; Pardo, R.; Deban, L. [Valladolid Univ., Dept. de Quimica Analitica, Facultad de Ciencias (Spain); Garcia-Talavera, P.; Singi, G.M.; Martin, E. [Hospital Clinico Univ., Servicio de Medicina Nuclear, Salamanca (Spain)

    2006-07-01

    Although the main concern regarding exposure to ionizing radiation for nuclear medicine workers is external radiation, inhalation of radionuclides can significantly contribute to the imparted doses. We propose a new approach to assess exposure to inhalation of {sup 131}I based on passive monitoring using activated charcoal detectors. We compared the inhalation doses to the staff of a nuclear medicine department, based on the measurements derived from charcoal detectors placed at various locations, and the external doses monitored using personal TLD dosimeters. (authors)

  20. A Modular High Sensitive Radiation Detector for Homel and Security and Post Event Applications

    International Nuclear Information System (INIS)

    A modular, high sensitive radiation monitoring system designed for the homeland security radiological requirements and radiological post event applications is presented. The prevention of undocumented and potentially threatening shipment of radioactive and nuclear materials is a problem at seaports, border crossings, rail yards, airports and similar locations that requires the use of sensitive radiation detectors. Furthermore; radiological events such as the Fukushima nuclear incident emphasize the need for sensitive detector for monitoring food and commercial products

  1. Characterizing the radiation response of Cherenkov glass detectors with isotopic sources

    Energy Technology Data Exchange (ETDEWEB)

    Hayward, J P [University of Tennessee, Knoxville (UTK); Hobbs, C. L. [University of Tennessee, Knoxville (UTK); Bell, Zane W [ORNL; Boatner, Lynn A [ORNL; Johnson, Rose E [ORNL; Ramey, Joanne Oxendine [ORNL; Jellison Jr, Gerald Earle [ORNL; Lillard, Cole R [ORNL; Ramey, Lucas A [ORNL

    2012-01-01

    Abstract Cherenkov detectors are widely used for particle identification and threshold detectors in high-energy physics. Glass Cherenkov detectors that are sensitive to beta emissions originating from neutron activation have been demonstrated recently as a potential replacement for activation foils. In this work, we set the groundwork to evaluate large Cherenkov glass detectors for sensitivity to MeV photons through first understanding the measured response of small Cherenkov glass detectors to isotopic gamma-ray sources. Counting and pulse height measurements are acquired with reflected glass Cherenkov detectors read out with a photomultiplier tube. Simulation was used to inform our understanding of the measured results. This simulation included radioactive source decay, radiation interaction, Cherenkov light generation, optical ray tracing, and photoelectron production. Implications for the use of Cherenkov glass detectors to measure low energy gammaray response are discussed.

  2. Measurement of ionising radiation semiconductor detectors: a review

    International Nuclear Information System (INIS)

    Manufacturing techniques for nuclear detectors using semiconductors are constantly advancing, and a large range of models with different specificities and characteristics are available. After a theoretical reminder, this report describes the main types of detectors, their working and their preferential use. A comparative table guides the neophyte reader in his choice

  3. Search for Physics beyond the Standard Model with the ATLAS detector and the development of radiation detectors

    CERN Document Server

    Silver, Yiftah

    We are investigating a radiation detector based on plasma display panel technology, the principal component of plasma television displays. This Plasma Panel Sensor (PPS) technology is a variant of micro-pattern gas radiation detectors. Based on the properties of existing plasma display panels, we expect eventually to be able to build a sealed array of plasma discharge gas cells to detect ionizing radiation with fast rise time of less than 10ns and high spatial resolution using a pixel pitch of less than 100 micrometer. In this thesis I shall describe our program of testing plasma display panels as detectors, including simulations, design and the first laboratory and beam studies that demonstrate the detection of cosmic ray muons, beta rays and medium energy protons. The ATLAS detector is used to search for high-mass resonances, in particular heavy neutral gauge bosons (Z') and excited states of Kaluza-Klein γ/Z bosons decaying to an electron-positron pair or a muon-antimuon pair. Results are presented based ...

  4. Studies of radiation hardness of MOS devices for application in a linear collider vertex detector

    International Nuclear Information System (INIS)

    The proposed International Linear Collider (ILC) together with the Large Hadron Collider (LHC) at CERN serve as a combined tool to explore the mysteries of the universe: the former is a precision machine and the latter can be considered as a finding machine. The key component of the ILC is the vertex detector that should be placed as close as possible to the Interaction Point (IP) and has better radiation tolerance against the dominant electron-positron pair production background from beam-beam interactions. A new generation of MOS-type Depleted-Field-Effect Transistor (MOSDEPFET) active pixel detectors has been proposed and developed by Semiconductor Labor Munich for Physics and for extraterrestrial Physics in order to meet the requirements of the vertex detector at the ILC. Since all MOS devices are susceptible to ionizing radiation, the main topic is focused on the radiation hardness of detectors, by which a series of physical processes are analyzed: e.g. surface damage due to ionizing radiation as well as damage mechanisms and their associated radiation effects. As a consequence, the main part of this thesis consists of a large number of irradiation experiments and the corresponding discussions. Finally, radiation hardness of the detectors should be improved through a set of concluded experiences that are based on a series of analysis of the characteristic parameters using different measurement techniques. The feasibility of the MOSDEPFET-based vertex detector is, therefore, predicted at ILC. (orig.)

  5. Studies of radiation hardness of MOS devices for application in a linear collider vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qingyu

    2008-10-17

    The proposed International Linear Collider (ILC) together with the Large Hadron Collider (LHC) at CERN serve as a combined tool to explore the mysteries of the universe: the former is a precision machine and the latter can be considered as a finding machine. The key component of the ILC is the vertex detector that should be placed as close as possible to the Interaction Point (IP) and has better radiation tolerance against the dominant electron-positron pair production background from beam-beam interactions. A new generation of MOS-type Depleted-Field-Effect Transistor (MOSDEPFET) active pixel detectors has been proposed and developed by Semiconductor Labor Munich for Physics and for extraterrestrial Physics in order to meet the requirements of the vertex detector at the ILC. Since all MOS devices are susceptible to ionizing radiation, the main topic is focused on the radiation hardness of detectors, by which a series of physical processes are analyzed: e.g. surface damage due to ionizing radiation as well as damage mechanisms and their associated radiation effects. As a consequence, the main part of this thesis consists of a large number of irradiation experiments and the corresponding discussions. Finally, radiation hardness of the detectors should be improved through a set of concluded experiences that are based on a series of analysis of the characteristic parameters using different measurement techniques. The feasibility of the MOSDEPFET-based vertex detector is, therefore, predicted at ILC. (orig.)

  6. Organic liquid scintillation detector shape and volume impact on radiation portal monitors

    Science.gov (United States)

    Paff, Marc G.; Clarke, Shaun D.; Pozzi, Sara A.

    2016-07-01

    We have developed and tested a radiation portal monitor using organic liquid scintillation detectors. In order to optimize our system designs, neutron measurements were carried out with three organic liquid scintillation detectors of different shapes and sizes, along with a 3He radiation portal monitor (RPM) as a reference. The three liquids tested were a 7.62 cm diameter by 7.62 cm length cylindrical active volume organic liquid scintillation detector, a 12.7 cm diameter by 12.7 cm length cylindrical active volume organic liquid scintillation detector, and a 25 cm by 25 cm by 10 cm "paddle" shaped organic liquid scintillation detector. Background and Cf-252 neutron measurements were recorded to allow for a comparison of neutron intrinsic efficiencies as well as receiver operating characteristics (ROC) curves between detectors. The 12.7 cm diameter cylindrical active volume organic liquid scintillation detector exhibited the highest intrinsic neutron efficiency (54%) of all three liquid scintillators. An ROC curve analysis for a heavily moderated Cf-252 measurement showed that using the 12.7 cm diameter by 12.7 cm length cylindrical active volume Eljen EJ309 organic liquid scintillation detector would result in the fewest needed detector units in order to achieve a near 100% positive neutron alarm rate while maintaining a better than 1 in 10,000 false alarm rate on natural neutron background. A small number of organic liquid scintillation detectors could therefore be a valid alternative to 3He in some RPM applications.

  7. Large arrays of discrete ionizing radiation detectors multiplexed using fluorescent optical converters

    International Nuclear Information System (INIS)

    This invention provides a radiation imaging system employing arrays of scintillators. An object of the invention is to produce a detector with high spatial resolution, high gamma-photon absorption efficiency, excellent source and detector scatter rejection, and utilizing low-cost solid state opto-electronic devices. In one embodiment, it provides a radiation detection and conversion apparatus having an array of optically isolated radiation sensitive elements that emit optical radiation upon absorption of ionizing radiation. An array of channels, comprising a material that absorbs and traps the radiation emitted and transports it or radiation that has been shifted to longer wavelengths, is placed near the radiation-sensitive elements. Electro-optical detectors that convert the transported radiation into electrical signals are coupled to the channels. The activation of one of the electro-optical devices by radiation from one of the channels indicates that at least one of the radiation-sensitive elements near that channel has absorbed a quantity of radiation

  8. The use of detectors based on ionisation recombination in radiation protection

    International Nuclear Information System (INIS)

    Intitial recombination of ionisation in a gas depends on the ionisation density and hence on the linear energy transfer along the tracks of charged particles. This effect can be used as a basis for instruments that respond to different types of ionising radiation approximately in the way required by the quality factor-linear energy transfer relation recommended by the ICRP for use in radiation protection. Empirical instruments based on ionisation recombination that have been used for radiation protection measurements are reviewed, and relations are derived from recombination theory that show that the response of such detectors can be readily predicted. The usefulness of recombination instruments in radiation protection is discussed and their advantages and limitations assessed. It is shown that their main application will be as reference instruments against which other detectors can be calibrated. As an extension to using recombination detectors as reference instruments, the feasibility of specifying radiation quality in terms of ionisation recombination is investigated. (author)

  9. Radiation and Background Levels in a CLIC Detector due to Beam-Beam Effects Optimisation of Detector Geometries and Technologies

    CERN Document Server

    Sailer, André; Lohse, Thomas

    2013-01-10

    The high charge density---due to small beam sizes---and the high energy of the proposed CLIC concept for a linear electron--positron collider with a centre-of-mass energy of up to 3~TeV lead to the production of a large number of particles through beam-beam interactions at the interaction point during every bunch crossing (BX). A large fraction of these particles safely leaves the detector. A still significant amount of energy will be deposited in the forward region nonetheless, which will produce secondary particles able to cause background in the detector. Furthermore, some particles will be created with large polar angles and directly cause background in the tracking detectors and calorimeters. The main sources of background in the detector, either directly or indirectly, are the incoherent $mathrm{e}^{+}mathrm{e}^{-}$ pairs and the particles from $gammagamma ightarrow$ hadron events. The background and radiation levels in the detector have to be estimated, to study if a detector is feasible, that can han...

  10. Chemical imaging of cotton fibers using an infrared microscope and a focal-plane array detector

    Science.gov (United States)

    In this presentation, the chemical imaging of cotton fibers with an infrared microscope and a Focal-Plane Array (FPA) detector will be discussed. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In addition, FPA detectors allow for simultaneous spe...

  11. Analyzing the efficiency of the forward radiation shielding for the CMS detector at the LHC

    CERN Document Server

    Azhgirey, L S

    2002-01-01

    The forward radiation shielding of the CMS detector is developed for the LHC by the Institute for High-Energy Physics. The efficiency of this shielding is analyzed on the basis of the results of numerical simulation. The computed particle-flux densities are compared to those of the ideal model of the shielding. The secondary-radiation field near the detector is investigated with different configurations of the shielding. Measures for reinforcing the shielding of the detector's experimental zone are proposed. The possibilities of improving the shielding structure and the composition of its materials are discussed. (13 refs).

  12. Defect analysis of silicon detectors made of different materials for radiation hardness

    CERN Document Server

    Dezillie, B; Li, Z

    1999-01-01

    A comparative study of the radiation hardness of single pad detectors, manufactured from standard float-zone (FZ) and epitaxial (Epi) n-type monocrystal silicon with comparable initial resistivity is presented. Detectors 2processed from FZ and Epi material with a low (400 OMEGA cm and 500 OMEGA cm) and a high (approx 2 k OMEGA cm) initial resistivity have been irradiated up to 4x10 sup 1 sup 4 n/cm sup 2 and measured under the same conditions in order to study the influence of the initial resistivity on the detector radiation hardness.

  13. Defect analysis of silicon detectors made of different materials for radiation hardness

    Energy Technology Data Exchange (ETDEWEB)

    Dezillie, B. E-mail: britta.dezillie@cern.ch; Eremin, V.; Li, Z

    1999-04-21

    A comparative study of the radiation hardness of single pad detectors, manufactured from standard float-zone (FZ) and epitaxial (Epi) n-type monocrystal silicon with comparable initial resistivity is presented. Detectors 2processed from FZ and Epi material with a low (400 {omega} cm and 500 {omega} cm) and a high ({approx}2 k{omega} cm) initial resistivity have been irradiated up to 4x10{sup 14} n/cm{sup 2} and measured under the same conditions in order to study the influence of the initial resistivity on the detector radiation hardness.

  14. Radiation hardness of silicon detectors manufactured on wafers from various sources

    Energy Technology Data Exchange (ETDEWEB)

    Dezillie, B. [European Organization for Nuclear Research, Geneva (Switzerland); Bates, S. [European Organization for Nuclear Research, Geneva (Switzerland); Glaser, M. [European Organization for Nuclear Research, Geneva (Switzerland); Lemeilleur, F. [European Organization for Nuclear Research, Geneva (Switzerland); Leroy, C. [University of Montreal, Montreal (Canada)

    1997-04-01

    Impurity concentrations in the initial silicon material are expected to play an important role for the radiation hardness of silicon detectors, during their irradiation and for their evolution with time after irradiation. This work reports on the experimental results obtained with detectors manufactured using various float-zone (FZ) and epitaxial-grown material. Preliminary results comparing the changes in leakage current and full depletion voltage of FZ and epitaxial detectors as a function of fluence and of time after 10{sup 14} cm{sup -2} proton irradiation are given. The measurement of charge collection efficiency for epitaxial detectors is also presented. (orig.).

  15. Radiation hard silicon microstrip detectors for use in ATLAS at CERN

    International Nuclear Information System (INIS)

    The Large Hadron Collider (LHC) at CERN (Geneva, Switzerland) will accelerate protons in colliding beams to a center of mass energy of 14 TeV at very high luminosities. The ATLAS detector is being built to explore the physics in this unprecedented energy range. Tracking of charged particles in high-energy physics (HEP) experiments requires a high spatial resolution and fast signal readout, all with as little material as possible. Silicon microstrip detectors meet these requirements well and have been chosen for the Semiconductor Tracker (SCT) which is part of the inner tracking system of ATLAS and has a total area of 61 m2. During the 10 years of operation at LHC, the total fluence received by the detectors is sufficiently large that they will suffer a severe degradation from radiation induced damage. The damage affects both the physics performance of the detectors as well as their operability and a great challenge has been to develop radiation hard detectors for this environment. An extensive irradiation programme has been carried out where detectors of various designs, including defect engineering by oxygen enriched silicon, have been irradiated to the expected fluence. A subsequent thermal annealing period is included to account for a realistic annual maintenance schedule at room temperature, during which the radiation induced defects alter the detector properties significantly. This thesis presents work that has been carried out in the Bergen ATLAS group with results both from the irradiation programme and from detector testing during the module production. (Author)

  16. Radiation hard silicon microstrip detectors for use in ATLAS at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Lars Gimmestad

    2005-07-01

    The Large Hadron Collider (LHC) at CERN (Geneva, Switzerland) will accelerate protons in colliding beams to a center of mass energy of 14 TeV at very high luminosities. The ATLAS detector is being built to explore the physics in this unprecedented energy range. Tracking of charged particles in high-energy physics (HEP) experiments requires a high spatial resolution and fast signal readout, all with as little material as possible. Silicon microstrip detectors meet these requirements well and have been chosen for the Semiconductor Tracker (SCT) which is part of the inner tracking system of ATLAS and has a total area of 61 m2. During the 10 years of operation at LHC, the total fluence received by the detectors is sufficiently large that they will suffer a severe degradation from radiation induced damage. The damage affects both the physics performance of the detectors as well as their operability and a great challenge has been to develop radiation hard detectors for this environment. An extensive irradiation programme has been carried out where detectors of various designs, including defect engineering by oxygen enriched silicon, have been irradiated to the expected fluence. A subsequent thermal annealing period is included to account for a realistic annual maintenance schedule at room temperature, during which the radiation induced defects alter the detector properties significantly. This thesis presents work that has been carried out in the Bergen ATLAS group with results both from the irradiation programme and from detector testing during the module production. (Author)

  17. Gamma-ray detectors for intelligent, hand-held radiation monitors

    International Nuclear Information System (INIS)

    Small radiation detectors based on HgI2, bismuth germanate (BGO), plastic, or NaI(Tl) detector materials were evaluated for use in small, lighweight radiation monitors. The two denser materials, HgI2 and BGO, had poor resolution at low-energy and thus performed less well than NaI(Tl) in detecting low-energy gamma rays from bare, enriched uranium. The plastic scintillator, a Compton recoil detector, also performed less well at low gamma-ray energy. Two small NaI(Tl) detectors were suitable for detecting bare uranium and sheilded plutonium. One became part of a new lightweight hand-held monitor and the other found uses as a pole-mounted detector for monitoring hard-to-reach locations

  18. Low radioactivity material for use in mounting radiation detectors

    Science.gov (United States)

    Fong, Marshall; Metzger, Albert E.; Fox, Richard L.

    1988-01-01

    Two materials, sapphire and synthetic quartz, have been found for use in Ge detector mounting assemblies. These materials combine desirable mechanical, thermal, and electrical properties with the radioactive cleanliness required to detect minimal amounts of K, Th, and U.

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

    CERN Document Server

    Prettyman, T H

    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 time- and position-dependent map that contains all possible charge pulses that can be produced by the detector for charge generated at discrete locations (e.g., by gamma-ray interactions). Because the map is generated by solving a single, time-dependent problem, the potential for reduction in computational effort over direct mapping methods is significant, particularly for detectors with complex electrode structures. In this paper, the adjoint equation is presented and the mapping method is validated for a benchmark problem.

  20. Method for mapping charge pulses in semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Prettyman, T.H.

    1998-12-01

    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 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 time- and position-dependent map that contains all possible charge pulses that can be produced by the detector for charge generated at discrete locations (e.g., by gamma-ray interactions). Because the map is generated by solving a single, time-dependent problem, the potential for reduction in computational effort over direct mapping methods is significant, particularly for detectors with complex electrode structures. In this paper, the adjoint equation is derived and the mapping method is illustrated for a simple case.

  1. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo;

    proportional to absorbed dose. A model by Hansen and Olsen, based on the Track Structure Theory is available, which can predict the relative efficiency of some detectors, when the particle spectrum is known. For alanine detectors the model was successfully validated by Hansen and Olsen for several ion species...... at energies below 20 MeV/u. We implemented this model in the Monte Carlo code FLUKA. At the GSI heavy ion facility in Darmstadt, Germany, alanine has been irradiated with carbon ions at energies between 88 an 400 MeV/u, which is the energy range used for therapy. The irradiation and the detector response have...... been simulated with FLUKA. We found an agreement between measured values of the relative efficiency with values predicted by the Hansen and Olsen model with divergence less than 4%. With the implementation in FLUKA we are able to simulate the detector response in the depth dose curves with precisions...

  2. Measurement of gamma and neutron radiations inside spent fuel assemblies with passive detectors

    Energy Technology Data Exchange (ETDEWEB)

    Viererbl, L., E-mail: vie@ujv.cz [Nuclear Research Institute Rez plc, 250 68 Husinec-Rez 130 (Czech Republic); Research Centre Rez Ltd. (Czech Republic); Lahodova, Z.; Voljanskij, A.; Klupak, V.; Koleska, M. [Nuclear Research Institute Rez plc, 250 68 Husinec-Rez 130 (Czech Republic); Research Centre Rez Ltd. (Czech Republic); Cabalka, M. [Nuclear Research Institute Rez plc, 250 68 Husinec-Rez 130 (Czech Republic); Turek, K. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic (Czech Republic)

    2011-10-01

    During operation of a fission nuclear reactor, many radionuclides are generated in fuel by fission and activation of {sup 235}U, {sup 238}U and other nuclides present in the assembly. After removal of a fuel assembly from the core, these radionuclides are sources of different types of radiation. Gamma and neutron radiation emitted from an assembly can be non-destructively detected with different types of detectors. In this paper, a new method of measurement of radiation from a spent fuel assembly is presented. It is based on usage of passive detectors, such as alanine dosimeters for gamma radiation and track detectors for neutron radiation. Measurements are made on the IRT-2M spent fuel assemblies used in the LVR-15 research reactor. During irradiation of detectors, the fuel assembly is located in a water storage pool at a depth of 6 m. Detectors are inserted into central hole of the assembly, irradiated for a defined time interval, and after the detectors removed from the assembly, gamma dose or neutron fluence are evaluated. Measured profiles of gamma dose rate and neutron fluence rate inside of the spent fuel assembly are presented. This measurement can be used to evaluate relative fuel burn-up.

  3. Measurement of gamma and neutron radiations inside spent fuel assemblies with passive detectors

    Science.gov (United States)

    Viererbl, L.; Lahodová, Z.; Voljanskij, A.; Klupák, V.; Koleška, M.; Cabalka, M.; Turek, K.

    2011-10-01

    During operation of a fission nuclear reactor, many radionuclides are generated in fuel by fission and activation of 235U, 238U and other nuclides present in the assembly. After removal of a fuel assembly from the core, these radionuclides are sources of different types of radiation. Gamma and neutron radiation emitted from an assembly can be non-destructively detected with different types of detectors. In this paper, a new method of measurement of radiation from a spent fuel assembly is presented. It is based on usage of passive detectors, such as alanine dosimeters for gamma radiation and track detectors for neutron radiation. Measurements are made on the IRT-2M spent fuel assemblies used in the LVR-15 research reactor. During irradiation of detectors, the fuel assembly is located in a water storage pool at a depth of 6 m. Detectors are inserted into central hole of the assembly, irradiated for a defined time interval, and after the detectors removed from the assembly, gamma dose or neutron fluence are evaluated. Measured profiles of gamma dose rate and neutron fluence rate inside of the spent fuel assembly are presented. This measurement can be used to evaluate relative fuel burn-up.

  4. Radiative Processes of the DeWitt-Takagi Detector

    CERN Document Server

    Díaz, D E

    2003-01-01

    We examine the excitation of a uniformly accelerated DeWitt-Takagi detector coupled quadratically to a Majorana-Dirac field. We obtain the transition probability from the ground state of the detector and the vacuum state of the field to an excited state with the emission of a Minkowski pair of quanta, in terms of elementary processes of absorption and scattering of Rindler quanta from the Fulling-Davies-Unruh thermal bath in the co-accelerated frame.

  5. A novel position sensitive detector for nuclear radiation. Final Report

    International Nuclear Information System (INIS)

    Current and next generation experiments in nuclear and elementary particle physics require detectors with high spatial resolution, fast response, and accurate energy information. Such detectors are required for spectroscopy, and imaging of optical and high-energy photons, charged particles, and neutrons, and are of interest not only in nuclear and high-energy physics, but also in other areas such as medical imaging, diffraction, astronomy, nuclear treaty verification, non-destructive evaluation, and geological exploration

  6. A new technique for the fabrication of thin silicon radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Foulon, F.; Rousseau, L.; Brambilla, A.; Bergonzo, P. [LETI/DEIN/SPE, Gif-sur-Yvette (France); Babadjian, L.; Spirkovitch, S. [Groupe ESIEE, Noisy-le-Grand (France)

    1999-06-01

    The fabrication of silicon radiation detectors with thicknesses lower than 30 {micro}m requires non-standard processing equipment and procedures. Such detectors are commonly manufactured by vias in thick silicon wafers of typically 300 {micro}m in order to locally create on small areas thin detectors. Since the etching step controls the thickness and uniformity of the detector, it must provide a constant and controllable etch rate and should not modify the surface micro-roughness, rendering this manufacturing technique critical. As an alternative, the authors have developed a new technique for the fabrication of thin detectors based on the use of substrates presenting a buried etch-stop layer. The detector thickness, its uniformity and the surface roughness are fixed and controlled by the substrate specifications. 5 to 30 {micro}m thick pin silicon diodes with surfaces ranging from 1 to 100 mm{sup 2} have been fabricated. Using this technique, thickness uniformity as low as {+-}0.05 {micro}m can be obtained on 5 {micro}m thick detectors over 100 mm{sup 2} area. 30 {micro}m thick pin detectors (S = 64 mm{sup 2}) are fully depleted at zero bias and exhibit an energy resolution of less than 120 keV ({approximately}2%) for 5.5 MeV alpha particles. This constitutes a breakthrough towards the low cost fabrication of thin silicon radiation detectors using planar technology.

  7. Evidence of Dopant Type-Inversion and Other Radiation Damage Effects of the CDF Silicon Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Ballarin, Roberto [Univ. of the Basque Country, Leioa (Spain)

    2010-06-01

    The aim of this document is to study the effect of radiation damage on the silicon sensors. The reflection of the effect of radiation can be observed in two fundamental parameters of the detector: the bias current and the bias voltage. The leakage current directly affects the noise, while the bias voltage is required to collect the maximum signal deposited by the charged particle.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. The radiation effect of 60Co gamma rays on polycarbonate detector

    International Nuclear Information System (INIS)

    The irradiation of polymeric materials with ionizing radiation (gamma rays, X rays, accelerated electrons, ion beams) leads to the formation of very reactive intermediates products (excited states, ions and free radicals), which result in rearrangements and/or formation of new bonds. The effects of these reactions are formation of oxidized products, grafts, scission of main chain (degradation) or cross-linking. Often the two processes (degradation - cross- linking) occur simultaneously, and the outcome of the process is determined by a competition between the reactions. Polycarbonate detectors are used as a particle track detector for neutrons and alpha particles detection. This work aims to study the ionizing radiation dose response of polycarbonate samples using spectrophotometric technique. A commercially available polycarbonate was analysed and its dosimetric characteristics were studied: radiation-induced absorption spectra, ambient light, temperature and humidity influence, pre- and post-irradiation stability, reproducibility and dose range useful response. Samples of polycarbonate (3 x 1 cm2) were irradiated with 60Co gamma radiation in free air at electronic equilibrium with absorbed doses between 1 and 95 kGy. When exposed to gamma radiation the polycarbonate detectors undergoes changes in their optical response, the colour variation is used for determining the absorbed dose. A Shimadzu UV-2101PC spectrophotometer was used for scanning the absorption spectra and measuring the optical density of film detectors irradiated with different radiation doses. Polycarbonate film detector are easy to prepare and to analyse, of good optical quality, inexpensive and of small size. The dosimetric accuracy can be affect by environmental conditions so, the detectors must be stored in appropriate conditions. The reproducibility of the detectors response can be improved by careful monitoring of optical densities before irradiation. The dose response curve presents linear

  10. alpha/beta radiation detector using wavelength and delayed fluorescence discrimination

    CERN Document Server

    Maekawa, T

    2002-01-01

    This paper describes a novel two-layer radiation detector for alpha/beta simultaneous counting for dust radiation monitoring in nuclear power plants. For alpha/beta discrimination, wavelength and delayed fluorescence discrimination techniques were newly developed. To establish the wavelength discrimination, we adopted a two-layer scintillator consisting of the plastic scintillator (NE-111A) and Y sub 2 O sub 2 S(Eu) whose emission spectra are quite different. To reject the mixed beta signal in the alpha detection layer, we used the delayed fluorescence characteristics of Y sub 2 O sub 2 S(Eu) in the signal processing. We manufactured the detector and tested its feasibility and the detection performance for dust radiation monitoring. Finally, we concluded that the performance of this new alpha/beta detector using the new discrimination methods is suitable for dust radiation monitoring.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Chemical modification of neoplastic cell transformation by heavy ion radiation

    International Nuclear Information System (INIS)

    Quantitative data on chemical modification of neoplastic cell transformation by heavy-ion radiation was obtained using in-vitro cell transformation technique. The specific aims were 1) to test the potential effects of various chemicals on the expression of cell transformation, and 2) to systematically collect information on the mechanisms of expression and progression of cell transformation by ionizing radiation. Recent experimental studies with DMSO, 5-azacytidine, and dexamethasone suggest that DMSO can effectively suppress the neoplastic cell transformation by high-LET radiation and that some nonmutagenic changes in DNA may be important in modifying the expression, and progression of radiation-induced cell transformation

  13. Modeling detector response in solid-state systems for radiation therapy and radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Hugtenburg, R.P. [School of Physics and Astronomy, University of Birmingham, B15 2TT, UK (United Kingdom); Bradley, D.A. [Department of Physics, University of Surrey, Guildford, GU2 7XH, UK (United Kingdom)

    2006-07-01

    In order for the many advantageous properties of solid-state dosimeters to be realised in clinic, strategies must be evolved for the calibration of detector systems for an ever expanding range of radiation sources including spectrally complex and mixed radiation fields. Monte Carlo models of the source and detector systems provide a means to account in a precise way for energy absorbed in the detector allowing for primary and secondary radiation processes including multiple scattering. Solid- state dosimeters including Si diodes, MOSFET, diamond detectors and doped optical fibres have been calibrated for dose in monoenergetic synchrotron X-rays in the range 5-50 keV, for quasi monoenergetic X-rays sources from 20-200 keV and for megavoltage X-ray and proton sources, such as are used in radical radiation therapy. With careful consideration of the elemental composition of the detector it is possible to achieve high quality agreement (2-3%) between measurement and Monte Carlo models of the variation of the detector response over a wide energy range. This information is needed in radiation therapy dosimetry where, for large external X-ray beams, detectors see a mixture of high energy primary photons and low energy (e.g. Compton scattered and pair-production-annihilation) photons. Typically, for solid-state detectors, different cavity theories are required for the two energy groups. In addition, high-Z constituents in detectors lead to an enhanced photoelectric absorption, which in the case of pure silicon detectors is up to 8 times greater than the tissue equivalent response. Information from maps of the elemental composition in the detectors, obtained via XRF and PIXE, is used in the models. Monte Carlo models are also being developed for contributions to the response from electron transport, including the microdosimetric response of detectors. Current Monte Carlo codes are able to handle large variations in density that typify tissue equivalent gas

  14. Strip type radiation detector and method of making same

    International Nuclear Information System (INIS)

    An improved strip detector and a method for making such a detector are described. A high resistivity N conduction semiconductor body has electrode strips formed thereon by diffusion. The strips are formed so as to be covered by an oxide layer at the surface point of the PN junction and in which the opposite side of the semiconductor body then has a substantial amount of material etched away to form a thin semiconductor upon which strip electrodes which are perpendicular to the electrodes on the first side are then placed

  15. Strip type radiation detector and method of making same

    International Nuclear Information System (INIS)

    An improved strip detector and a method for making such a detector in which a high resistivity N conduction semiconductor body has electrode strips formed thereon by diffusion is described. The strips are formed so as to be covered by an oxide layer at the surface point of the PN junction and in which the opposite side of the semiconductor body then has a substantial amount of material etched away to form a thin semiconductor upon which strip electrodes which are perpendicular to the electrodes on the first side are then placed

  16. Technical Note: Response measurement for select radiation detectors in magnetic fields

    International Nuclear Information System (INIS)

    Purpose: Dose response to applied magnetic fields for ion chambers and solid state detectors has been investigated previously for the anticipated use in linear accelerator–magnetic resonance devices. In this investigation, the authors present the measured response of selected radiation detectors when the magnetic field is applied in the same direction as the radiation beam, i.e., a longitudinal magnetic field, to verify previous simulation only data. Methods: The dose response of a PR06C ion chamber, PTW60003 diamond detector, and IBA PFD diode detector is measured in a longitudinal magnetic field. The detectors are irradiated with buildup caps and their long axes either parallel or perpendicular to the incident photon beam. In each case, the magnetic field dose response is reported as the ratio of detector signals with to that without an applied longitudinal magnetic field. The magnetic field dose response for each unique orientation as a function of magnetic field strength was then compared to the previous simulation only studies. Results: The measured dose response of each detector in longitudinal magnetic fields shows no discernable response up to near 0.21 T. This result was expected and matches the previously published simulation only results, showing no appreciable dose response with magnetic field. Conclusions: Low field longitudinal magnetic fields have been shown to have little or no effect on the dose response of the detectors investigated and further lend credibility to previous simulation only studies

  17. Active noise canceling system for mechanically cooled germanium radiation detectors

    Science.gov (United States)

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

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

    CERN Document Server

    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...

  19. Radiation Measurements of the Mars Science Lab Radiation Assessment Detector (MSL-RAD) on the Surface of Mars

    OpenAIRE

    Reitz, Guenther; Matthiä, Daniel; Hassler, Donald M.; Wimmer-Schweingruber, Robert; Ehresmann, Bent; Zeitlin, Cary; Guo, Jingnan; Koehler, Jan

    2016-01-01

    The Radiation Assessment Detector (RAD) was designed to characterize the radiation environment as “Life Limiting Factor” to habitability and to help to prepare for future human exploration of Mars. The Mars Science Laboratory spacecraft (MSL), containing the Curiosity rover, in which RAD is integrated, was launched to Mars on November 26, 2011. Although not part of the mission planning, RAD was operated already during the 253 day and 560 million km cruise to Mars and made the first detailed a...

  20. Disk shaped radiation sources for education purposes made of chemical fertilizer

    International Nuclear Information System (INIS)

    A method for fabricating a disk-shaped radiation source from material containing natural radioisotopes was developed. In this compression and formation method, a certain amount of powdered material is placed in a stainless steel formwork and compressed to form a solid disk. Using this method, educational radiation sources were fabricated using commercially available chemical fertilizers that naturally contain the radionuclide, 40K, which emits either beta or gamma rays, at each disintegration. The compression and formation method was evaluated by inspecting eleven radiation sources thus fabricated. Then the suitability of the fertilizer radiation source as an education aid was evaluated. The results showed that the method could be used to fabricate radiation sources without the need for learning special skills or techniques. It was also found that the potassium fertilizer radiation source could be used to demonstrate that the inverse-square law can be applied to the distance between the radiation source and detector, and that an exponential relationship can be seen between the shielding effectiveness and the total thickness of the shielding materials. It is concluded that a natural fertilizer radiation source is an appropriate aid for demonstrating the characteristics of radiation. (author)

  1. Radiation-chemical hardening of epoxyoligoesteracrylates

    International Nuclear Information System (INIS)

    The paint and varnish epoxide compositions radiation-hardened with the following warm-up (γ-radiation of 60%, dose rate 1 Gy/s; accelerated electrons, dose rate 1.7 kGy/s) are obtained. Therewith both methods of epoxy group inclusions into a three-dimensional net are coincided: preliminary epoxy resin modification by methacrylic acid and inclusion ternary amine into compositions. Physicomechanical and electric characteristics of oligomeric compositions are presented

  2. Radiation protection in the pharmaceutical-chemical industry

    International Nuclear Information System (INIS)

    Some aspects of the use of ionizing radiation in research in the pharmaceutical and chemical industries will be discussed, the emphasis being placed on the handling of open radioactive materials in research laboratories. The compliance with official regulations and the preparation of company internal radiation protection regulations are described. 1 tab., 9 refs

  3. Radiation-Hard Opto-Link for the Atlas Pixel Detector

    OpenAIRE

    Gan, K. K.

    2004-01-01

    The on-detector optical link of the ATLAS pixel detector contains radiation-hard receiver chips to decode bi-phase marked signals received on PIN arrays and data transmitter chips to drive VCSEL arrays. The components are mounted on hybrid boards (opto-boards). We present results from the opto-boards and from irradiation studies with 24 GeV protons up to 33 Mrad (1.2 x 10^15 p/cm^2).

  4. Measurement of the radiation field at the Collider Detector at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    K. Kordas et al.

    2003-01-12

    We present direct measurements of the spatial distribution of both ionizing radiation and low energy neutrons (E{sub n} < 200 keV) inside the tracking volume of the Collider Detector at Fermilab (CDF). Using data from multiple exposures we are able to separate the contributions from beam losses and proton-antiproton collisions. Initial measurements of leakage currents in the CDF silicon detectors show patterns consistent with predictions based on our measurements.

  5. SiC detectors for radiation sources characterization and fast plasma diagnostic

    Science.gov (United States)

    Cannavò, A.; Torrisi, L.

    2016-09-01

    Semiconductor detectors based on SiC have been investigated to characterize the radiations (photons and particles) emitted from different sources, such as radioactive sources, electron guns, X-ray tubes and laser-generated plasmas. Detectors show high response velocity, low leakage current, high energy gap and high radiation hardness. Their high detection efficiency permits to use the detectors in spectroscopic mode and in time-of-flight (TOF) approach, generally employed to monitor low and high radiation fluxes, respectively. Using the laser start signal, they permit to study the properties of the generated plasma in vacuum by measuring accurately the particle velocity and energy using pulsed lasers at low and high intensities. Possible applications will be reported and discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Observation of microwave radiation using low-cost detectors at the ANKA storage ring*

    CERN Document Server

    Judin, V; Hofmann, A; Huttel, E; Kehrer, B; Klein, M; Marsching, S; Müller, A S; Nasse, M; Smale, N; Caspers, F; Peier, P

    2011-01-01

    Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed, because the vacuum chamber cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: the accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches [1]. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths below the waveguide shielding cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually use...

  8. High-resolution detectors for medical applications and synchrotron radiation research

    Science.gov (United States)

    Babichev, E. A.; Baru, S. E.; Grigoriev, D. N.; Groshev, V. R.; Leonov, V. V.; Papushev, P. A.; Porosev, V. V.; Savinov, G. A.; Shayakhmetov, V. R.; Shekhtman, L. I.; Tikhonov, Yu. A.; Ukraintsev, Yu. G.; Yurchenko, Yu. B.

    2011-02-01

    In the present report, we summarize our experience in the development of high-resolution position sensitive gas detectors for medicine and synchrotron radiation experiments at Budker Institute of Nuclear Physics for the last years. We have designed several versions of Multistrip Ionisation Chambers with a channel pitch varying from 0.4 down to 0.1 mm. The high quantum efficiency (>65%) of these detectors allow its application in high quality diagnostic imaging. The detector with 0.1 mm strip pitch and 20 atm pressure of Xe demonstrates the best possible DQE and spatial resolution for gaseous detectors in a wide range of X-ray energies. Additionally, the initial results of feasibility study of the detector for beam position monitoring for Heavy Ion Therapy System are presented too.

  9. Investigation of GEM-Micromegas Detector on X-ray Beam of Synchrotron Radiation

    CERN Document Server

    Zhang, YuLian; Hu, BiTao; Fan, ShengNan; Wang, Bo; Liu, Mei; Zhang, Jian; Liu, RongGuang; Chang, GuangCai; Liu, Peng; Ouyang, Qun; Chen, YuanBo; Yi, FuTing

    2013-01-01

    To solve the discharge of the standard Bulk Micromegas and GEM detector, the GEM-Micromegas detector was developed in Institute of High Energy Physics. Taking into account the advantages of the two detectors, one GEM foil was set as a preamplifier on the mesh of Micromegas in the structure and the GEM preamplification decreased the working voltage of Micromegas to reduce the effect of the discharge significantly. In the paper, the performance of detector in X-ray beam was studied at 1W2B laboratory of Beijing Synchrotron Radiation Facility. Finally, the result of the energy resolution under various X-ray energies was given in different working gases. It indicated that the GEM-Micromegas detector had the energy response capability in all the energy range and it could work better than the standard Bulk-Micromegas.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Influence of field effect on the performance of InGaAs-based terahertz radiation detectors

    CERN Document Server

    Minkevičius, Linas; Kojelis, Martynas; Žąsinas, Ernestas; Bukauskas, Virginijus; Šetkus, Arūnas; Kašalynas, Irmantas; Valušis, Gintaras

    2016-01-01

    Detailed electric characterization of high-performance InGaAs-based terahertz radiation detectors and corresponding simulation results are presented. The local surface potential and tunneling current were scanned on the surface of detectors by Kelvin probe force microscope (KPFM) and scanning tunneling microscope (STM) and a position of the Fermi level was obtained from these experiments. Current-voltage curves were measured and modelled using Synopsys Sentaurus TCAD package to get a better insight of processes happening within the detector. In addition, finite-difference time-domain simulations were performed to reveal the peculiarities of electric field concentration by the metal contacts of the detectors. Results of our investigation confirm, that field-effect induced conductivity modulation is a possible contributing mechanism to high sensitivity of the detectors.

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

    International Nuclear Information System (INIS)

    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 μm) 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

  13. Studies of the radiation hardness of oxygen-enriched silicon detectors

    CERN Document Server

    Ruzin, A; Glaser, M; Lemeilleur, F

    1999-01-01

    Detectors of high-energy particles sustain substantial structural defects induced by the particles during the operation period. Some of the defects have been found to be electrically active, degrading the detector's performance. Understanding the mechanisms of the electrical activities and learning to suppress their influence are essential if long 'lifetime' detectors are required. This work report s about radiation hardness of silicon P-I-N devices fabricated from oxygen-enriched, high-resistivity material. The high and nearly uniform concentration of oxygen in float-zone silicon has been achie ved by diffusion of oxygen from SiO2 layers.

  14. Thallium bromide chloride (TlBrxCl1-x) nuclear radiation detector

    International Nuclear Information System (INIS)

    Thallium bromide (TlBr) has been studied as an X- and gamma-ray detector material and relatively good spectrometric performances have been obtained from the detectors. However, the energy resolution of the TlBr detectors is limited by the relatively low resistivity of the crystals. Thallium bromide chloride (TlBrxCl1-x) is a mixed crystal of TlBr and thallium chloride (TlCl). TlBr0.8Cl0.2 crystals have been grown by the traveling molten zone method (TMZ) from purified materials. Nuclear radiation detectors have been fabricated from the grown TlBr0.8Cl0.2 crystals and the detector performance has been characterized. Optical transmittance was evaluated in order to characterize bandgap of the grown crystal. The results confirm that the bandgap of TlBr0.8Cl0.2 is wider than the bandgap of TlBr. Leakage currents of the detectors were measured as a function of the bias voltage at room temperature. The resistivity of the TlBr0.8Cl0.2 detector is approximately equal to the resistivity of typical TlBr detector. A TlBr0.8Cl0.2 detector operated at room temperature was irradiated with gamma-rays from 137Cs source. The detector exhibited a clear peak corresponding 662 keV gamma-rays. The resolution obtained by the TlBr0.8Cl0.2 detector, however, was presently not better than the resolution obtained by the typical TlBr detector. (M. Suetake)

  15. Palladium silicide - a new contact for semiconductor radiation detectors

    International Nuclear Information System (INIS)

    Silicide layers can be used as low resistance contacts in semiconductor devices. The formation of a metal rich palladium silicide Pd2Si is discussed. A palladium film 100A thick is deposited at 3000C and the resulting silicide layer used as an ohmic contact in an n + p silicon detector. This rugged contact has electrical characteristics comparable with existing evaporated gold contacts and enables the use of more reproducible bonding techniques. (author)

  16. Time expansion chambers of the ALICE Transition Radiation Detector (TRD)

    CERN Multimedia

    2003-01-01

    The TRD is segmented into 18 sectors in the azimuthal angle. Each sector consists of 6 layers in the radial direction and is composed of 5 stacks in the longitudinal direction. This amounts to 540 individual detector modules with a total active area of roughly 750 m2 and 1.2 million readout channels. The largest module is 159 cm long and 120 cm wide.

  17. Characterization of Silicon Photomultiplier Detectors using Cosmic Radiation

    Science.gov (United States)

    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.

  18. Application of MCP-N (Lif: Mg, Cu, P TL detectors in monitoring environmental radiation

    Directory of Open Access Journals (Sweden)

    Olko Pavel

    2004-01-01

    Full Text Available Thermoluminescent MCP-N detectors based on LiF:Mg,Cu,P are by about 2 orders of magnitude more sensitive than TLD-100 detectors based on conventional LiF:Mg,Ti, which makes it possible to use them in short-term monitoring of ionizing radiation in the environment (e. g., over a two-week period, rather than over 3-12 months. We describe the properties of MCP-N detectors and methods of their application in environmental monitoring. The system was tested in short and long-term exposure periods at 100 sites around Krakow region. MCP-N detectors were then applied to measure variation of radiation dose rate at four selected villages in Serbia, where depleted uranium ammunition was deployed in 1999. Together with short-term thermoluminescent dosimetry, in situ measurements using proportional counters were per formed in order to assess the range of variation of natural radiation background in these villages. The mean terrestrial kerma dose rate in these villages was found to vary between 85 and 116 nGyh–1 and the average ambient dose equivalent rate H*(10 determined by thermoluminescent detectors and by proportional counter measurements was 160 nSvh–1. These values of natural radiation back ground dose rates can be applied as reference levels for field measurements around other sites where depleted uranium ammunition was deployed.

  19. Radiation hardness of punch-through and FET biased silicon microstrip detectors

    International Nuclear Information System (INIS)

    Silicon microstrip detectors can be biased with polysilicon resistors or Field Effect Transistor (FET) biasing structures. Polysilicon resistors are radiation hard, but using the FET biasing principle reduces processing costs and can give better noise performance. A set of microstrip detectors has been manufactured with a standard radiation sensor process in order to assess the radiation hardness of punch-through and FET biasing. Eight different bias geometry designs were used in order to study the effects of bias gap lengths and strip end geometries on the detector characteristics. The test detectors were irradiated at several dose levels up to 75 kGy with a 60Co source. Initially the devices had very low oxide charge (3.1010 cm-2) and leakage current levels (60 pA per strip). The dynamic resistance was in the 1 GΩ range, which is higher than the values which can be achieved by conventional polysilicon resistors. Radiation exposure gave significant increases in the leakage current of the devices. This causes large reductions in the dynamic resistance, and detector performance will degrade. The degradation due to increased leakage current was present for all strip end geometries, and it could not be compensated by changing the gate voltage. (orig.)

  20. Chemical resistance of optical plastics and resin for level detectors

    Science.gov (United States)

    Omegna, Cicero L.; Fontes Garcia, Jonas; Ramos-Gonzáles, Roddy E.; Barbosa, Luiz C.

    2015-09-01

    A test method was developed to find the ideal optical material that supports the chemical reaction of some fuels. Optical plastics and resin were submerged for long periods of time in reservoirs of ethanol, gasoline, Diesel and biodiesel. The dimensional change and weight change of the submerged samples was measured. A special resin successfully supported the chemical attack of fuels. Samples of acrylic polymer and polycarbonate were used as type of optical plastic.

  1. Simulation of active-edge pixelated CdTe radiation detectors

    OpenAIRE

    Duarte, DD; Lipp, JD; Schneider, A.; Seller, P; Veale, MC; Wilson, MD; Baker, MA; Sellin, PJ

    2016-01-01

    The edge surfaces of single crystal CdTe play an important role in the electronic properties and performance of this material as an X-ray and γ-ray radiation detector. Edge effects have previously been reported to reduce the spectroscopic performance of the edge pixels in pixelated CdTe radiation detectors without guard bands. A novel Technology Computer Aided Design (TCAD) model based on experimental data has been developed to investigate these effects. The results presented in this paper sh...

  2. Effects of radiation and chemical substances on cells and organism

    International Nuclear Information System (INIS)

    The book treats the radiation chemistry part of biophysics and applied biophysics in the sphere of ionizing radiation. Discussed are the concepts of radiation units and radioactivity units and the relative biological efficiency. The effects of ionizing and UV radiations are analyzed at the level of macromolecular changes. Chapters dealing with genetic radiation effects discuss the effects at the cellular level with respect to cell proliferation. All these problems are used to illustrate the effect on the organism as a whole. The chapters on applied biophysics deal with the indications of radiation and chemical damage, sensitivity of cells and the organism, and the study and influencing of growth at the cellular level. The concluding chapter is devoted to the environmental impact of radiation. (J.P.)

  3. Studying radiative B decays with the Atlas detector; Etude des desintegrations radiatives des mesons B dans le detecteur ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Viret, S

    2004-09-01

    This thesis is dedicated to the study of radiative B decays with the ATLAS detector at the LHC (large hadron collider). Radiative decays belong to the rare decays family. Rare decays transitions involve flavor changing neutral currents (for example b {yields} s{gamma}), which are forbidden at the lowest order in the Standard Model. Therefore these processes occur only at the next order, thus involving penguin or box diagrams, which are very sensitive to 'new physics' contributions. The main goal of our study is to show that it would be possible to develop an online selection strategy for radiative B decays with the ATLAS detector. To this end, we have studied the treatment of low energy photons by the ATLAS electromagnetic calorimeter (ECal). Our analysis shows that ATLAS ECal will be efficient with these particles. This property is extensively used in the next section, where a selection strategy for radiative B decays is proposed. Indeed, we look for a low energy region of interest in the ECal as soon as the level 1 of the trigger. Then, photon identification cuts are performed in this region at level 2. However, a large part of the proposed selection scheme is also based on the inner detector, particularly at level 2. The final results show that large amounts of signal events could be collected in only one year by ATLAS. A preliminary significance (S/{radical}B) estimation is also presented. Encouraging results concerning the observability of exclusive radiative B decays are obtained. (author)

  4. Radiation-chemical degradation of cellulose and other polysaccharides

    International Nuclear Information System (INIS)

    Results of studies on the radiation-chemical transformations of cellulose, its ethers, and some other polysaccharides (xylan, starch, dextran, chitin, chitosan, and heparin) are discussed. Ionising radiation causes the degradation of these compounds accompanied by decomposition of the pyranose ring and formation of compounds with carbonyl and carboxy groups, as well as formation of hydrogen, carbon dioxide, and carbon monoxide. The efficiency of degradation increases considerably with temperature and depends on the structure of the polysaccharide and the nature of its substituents. A mechanism of the radiation-chemical transformations of cellulose and other polysaccharides is suggested. The prospects of using radiation-chemical methods for processing of cellulose and other polysaccharides in industry and agriculture are considered. The bibliography includes 213 references.

  5. Investigation of polyethylene detector and adiabatic calorimeter in the radiation filds of proton accelerators

    International Nuclear Information System (INIS)

    The results on investigation of the absorbed energy detectors used at IHEP, i. e., polyethylene detector (PD)-based on hydrogen release from polymer under effect of ionizing radiation and adiabatic calorimeter (AC) are presented. The sensitivity function for these detectors for 6 MeV-3000 GeV hadrons have been calculated. The PD and AC readings have been measured and calculated for the radiation fields near the IHEP proton synchrotron vacuum chamber. The dependence of the calorimeter readings on the working medium has been studied. The PD has been calibrated with the AC. It is ahown that in the hadron spectra the calorimeter readings do not depend on the working medium in the limit of 8%. The PD calibration enchanced the accuracy of radiation dose measuring in the accelerator radiation mixed field. The sensitivity function calculations showed that detectors studied applied for measuring absorved dose have the energy threshold, so for PD it is equal 18 MEV for protons, 6 MeV for charged poins. Results of investigations showed the possibility of PD utilization for measuring absorbed dose in different structural materials operating in mixed radiation fields of accelerators

  6. Novel Surface Preparation and Contacts for CdZnTe Nuclear Radiation Detectors Using Patterned Films of Semiconductors and Insulators

    Science.gov (United States)

    Burger, Arnold; Groza, Michael; Conway, Adam; Payne, Steve

    2013-04-01

    The semiconductor Cadmium Zinc Telluride (CZT) has emerged as the material of choice for room temperature detection of X-rays and gamma-rays. The detectors will cover the energy range from 30 keV to several MeV, and will achieve excellent 662 keV energy resolution. The development of high resolution gamma ray detectors based on CZT is dependent on low electronic noise levels. One common source of noise is the surface leakage current, which limits the performance of advanced readout schemes such as the coplanar grid and pixelated architectures with steering grids. Excessive bulk leakage current can result from one of several surface effects: leaky native oxides, unsatisfied bonds, and surface damage. We propose to fabricate and test oriented [111] CZT crystals with thicknesses up to 1.5 cm with an innovative detection technique based on co-planar or other electron only transport designs using plasma processing, thin film sputtering, chemical passivation and wet etching techniques. Compared to conventional pixel detectors, the proposed contact configuration needs lower power consumption and a lower cost. The detector design can be used for building very low-cost handheld radiation detection devices.

  7. A Cherenkov Radiation Detector with High Density Aerogels

    CERN Document Server

    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.

  8. Radiation by an Unruh-DeWitt Detector in Oscillatory Motion

    CERN Document Server

    Lin, Shih-Yuin

    2016-01-01

    Quantum radiated energy flux emitted by an Unruh-DeWitt (UD) detector, with the internal harmonic oscillator coupled to a massless scalar field, in linear oscillatory motion in (3+1) dimensional Minkowski space is studied by numerical methods. Our results show that quantum interference can indeed suppress the signal of the Unruh effect if the averaged proper acceleration is sufficiently low, but not in the regime with high averaged acceleration and short oscillatory cycle. While the averaged radiated energy flux over a cycle is always positive as guaranteed by the quantum inequalities, an observer at a fixed angle may see short periods of negative radiated energy flux in each cycle of motion, which indicates that the radiation is squeezed. This reveals another resemblance between the detector theory and the moving-mirror model.

  9. Exploring graphene field effect transistor devices to improve spectral resolution of semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Richard Karl [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen Wayne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Jeffrey B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hamilton, Allister B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-12-01

    Graphene, a planar, atomically thin form of carbon, has unique electrical and material properties that could enable new high performance semiconductor devices. Graphene could be of specific interest in the development of room-temperature, high-resolution semiconductor radiation spectrometers. Incorporating graphene into a field-effect transistor architecture could provide an extremely high sensitivity readout mechanism for sensing charge carriers in a semiconductor detector, thus enabling the fabrication of a sensitive radiation sensor. In addition, the field effect transistor architecture allows us to sense only a single charge carrier type, such as electrons. This is an advantage for room-temperature semiconductor radiation detectors, which often suffer from significant hole trapping. Here we report on initial efforts towards device fabrication and proof-of-concept testing. This work investigates the use of graphene transferred onto silicon and silicon carbide, and the response of these fabricated graphene field effect transistor devices to stimuli such as light and alpha radiation.

  10. RADIATION HARDNESS / TOLERANCE OF SI SENSORS / DETECTORS FOR NUCLEAR AND HIGH ENERGY PHYSICS EXPERIMENTS.

    Energy Technology Data Exchange (ETDEWEB)

    LI,Z.

    2002-09-09

    Silicon sensors, widely used in high energy and nuclear physics experiments, suffer severe radiation damage that leads to degradations in sensor performance. These degradations include significant increases in leakage current, bulk resistivity, and space charge concentration. The increase in space charge concentration is particularly damaging since it can significantly increase the sensor full depletion voltage, causing either breakdown if operated at high biases or charge collection loss if operated at lower biases than full depletion. Several strategies can be used to make Si detectors more radiation had tolerant to particle radiations. In this paper, the main radiation induced degradations in Si detectors will be reviewed. The details and specifics of the new engineering strategies: material/impurity/defect engineering (MIDE); device structure engineering (DSE); and device operational mode engineering (DOME) will be given.

  11. Determination of Potassium in Fertilizer via Gamma Radiation by HPGe detector

    International Nuclear Information System (INIS)

    Full text: The feasibility of determining the total potassium content in fertilizers by measuring gamma radiation from potassium-40 was evaluated. The radiation was measured by a high purity germanium (HPGe) detector. We measured six different fertilizer samples. Calibration curve against the standard was found to be linear. The measured values of potassium from the experiment were close to potassium content shown by the producers. The potassium content of four product samples (F3, F4, F5 and F6) measured from the experiment was less than the value specified on the product label. One of the six samples (F2) has the potassium content greater than that presented on the product label. One sample (F1) did not emit any gamma radiation, agreeing with the fertilizer formula (zero potassium content). The analysis of potassium in fertilizers via gamma radiation measuring by HPGe detector has proven to be a good way to estimate the potassium content in the samples

  12. Radiation-induced chemical evolution of biomolecules

    International Nuclear Information System (INIS)

    Chemical evolution in glycilglycine (Gly2) films irradiated with 146 nm vacuum ultraviolet light was studied. It is found that quantum efficiency of chemical evolution from Gly2 to glycilglycilglycine (Gly3) is smaller than that to glycilglycilglycilglycine (Gly4) due to the multiple step of reaction. Furthermore, we have carried out measurement of soft X-ray natural circular dichroism spectra for serine and alanine films in the energy region of oxygen 1s transition and we report the splitting of 1s→π* transitions.

  13. Radiative transfer modeling of surface chemical deposits

    Science.gov (United States)

    Reichardt, Thomas A.; Kulp, Thomas J.

    2016-05-01

    Remote detection of a surface-bound chemical relies on the recognition of a pattern, or "signature," that is distinct from the background. Such signatures are a function of a chemical's fundamental optical properties, but also depend upon its specific morphology. Importantly, the same chemical can exhibit vastly different signatures depending on the size of particles composing the deposit. We present a parameterized model to account for such morphological effects on surface-deposited chemical signatures. This model leverages computational tools developed within the planetary and atmospheric science communities, beginning with T-matrix and ray-tracing approaches for evaluating the scattering and extinction properties of individual particles based on their size and shape, and the complex refractive index of the material itself. These individual-particle properties then serve as input to the Ambartsumian invariant imbedding solution for the reflectance of a particulate surface composed of these particles. The inputs to the model include parameters associated with a functionalized form of the particle size distribution (PSD) as well as parameters associated with the particle packing density and surface roughness. The model is numerically inverted via Sandia's Dakota package, optimizing agreement between modeled and measured reflectance spectra, which we demonstrate on data acquired on five size-selected silica powders over the 4-16 μm wavelength range. Agreements between modeled and measured reflectance spectra are assessed, while the optimized PSDs resulting from the spectral fitting are then compared to PSD data acquired from independent particle size measurements.

  14. Optimized digital filtering techniques for radiation detection with HPGe detectors

    Science.gov (United States)

    Salathe, Marco; Kihm, Thomas

    2016-02-01

    This paper describes state-of-the-art digital filtering techniques that are part of GEANA, an automatic data analysis software used for the GERDA experiment. The discussed filters include a novel, nonlinear correction method for ballistic deficits, which is combined with one of three shaping filters: a pseudo-Gaussian, a modified trapezoidal, or a modified cusp filter. The performance of the filters is demonstrated with a 762 g Broad Energy Germanium (BEGe) detector, produced by Canberra, that measures γ-ray lines from radioactive sources in an energy range between 59.5 and 2614.5 keV. At 1332.5 keV, together with the ballistic deficit correction method, all filters produce a comparable energy resolution of ~1.61 keV FWHM. This value is superior to those measured by the manufacturer and those found in publications with detectors of a similar design and mass. At 59.5 keV, the modified cusp filter without a ballistic deficit correction produced the best result, with an energy resolution of 0.46 keV. It is observed that the loss in resolution by using a constant shaping time over the entire energy range is small when using the ballistic deficit correction method.

  15. Use of glasses as radiation detectors for high doses

    International Nuclear Information System (INIS)

    Glass samples were tested in relation to the possibility of use in high dose dosimetry in medical and industrial areas. The main characteristics were determined: detection threshold, reproducibility, response to gamma radiation of 137Cs and 6 Co and thermal decay at ambient temperature, with the use of optical absorption and thermoluminesce techniques. (author)

  16. Thermoluminescent detector for mixed gamma and fast neutron radiations

    International Nuclear Information System (INIS)

    A thermoluminescent film badge suitable for military use is equally sensitive to gamma radiation and fast neutrons. It preferably contains calcium fluoride powder embedded in a matrix of cross-linked polyethylene, which has a hydrogen content of about 14 weight percent. Some details of the way in which the device is constructed are given. (N.D.H.)

  17. Radiation-hard Optoelectronics for LHC detector upgrades.

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00375195; Newbold, Dave

    A series of upgrades foreseen for the LHC over the next decade will allow the proton-proton collisions to reach the design center of mass energy of 14 TeV and increase the luminosity to five times (High Luminosity-LHC) the design luminosity by 2027. Radiation-tolerant high-speed optical data transmission links will continue to play an important role in the infrastructure of particle physics experiments over the next decade. A new generation of optoelectronics that meet the increased performance and radiation tolerance limits imposed by the increase in the intensity of the collisions at the interaction points are currently being developed. This thesis focuses on the development of a general purpose bi-directional 5 Gb/s radiation tolerant optical transceiver, the Versatile Transceiver (VTRx), for use by the LHC experiments over the next five years, and on exploring the radiation-tolerance of state-of-the art silicon photonics modulators for HL-LHC data transmission applications. The compliance of the VTRx ...

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

    CERN Document Server

    Moll, M; Al-Ajili, A 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; Bölla, G; Bondarenko, G B; 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; Betta, G F D; Dawson, I; de Boer, Wim; 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; García, C; García-Navarro, J E; Gaubas, E; Genest, M H; Gill, K A; Giolo, K; Glaser, M; Gössling, C; Golovine, V; Sevilla, S G; Gorelov, I; Goss, J; Bates, A G; Grégoire, G; Gregori, P; Grigoriev, E; Grillo, A A; Groza, A; Guskov, J; Haddad, L; Härkönen, J; Hauler, F; Hoeferkamp, M; Honniger, F; Horazdovsky, T; Horisberger, Roland Paul; Horn, M; Houdayer, A; Hourahine, B; Hughes, G; Ilyashenko, Yu S; 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 A; 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 M; Lastovetsky, V F; Latino, G; Lazanu, S; Lazanu, I; Lebedev, A; Lebel, C; Leinonen, K; Leroy, C; Li Z; Lindström, G; Linhart, V; Litovchenko, A P; Litovchenko, P G; Lo Giudice, A; Lozano, M; Luczynski, Z; Luukka, P; Macchiolo, A; Makarenko, L F; Mandic, I; Manfredotti, C; Manna, N; Garcia, S Mi; Marunko, S; Mathieson, K; Melone, J; Menichelli, D; Messineo, A; Metcalfe, J; Miglio, S; Mikuz, M; Miyamoto, J; Monakhov, E; Moscatelli, F; Naoumov, D; Nossarzhevska, 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; Pospísil, S; Pozza, A; Radicci, V; Rafí, J M; Rando, R; Röder, 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 J; Sentenac, D; Shipsey, I; Sícho, 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

    2005-01-01

    The envisaged upgrade of the Large Hadron Collider (LHC) at CERN towards the Super-LHC (SLHC) with a 10 times increased luminosity of 10challenges 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 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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z. E-mail: zhengl@bnl.gov; Dezillie, B.; Bruzzi, M.; Chen, W.; Eremin, V.; Verbitskaya, E.; Weilhammer, P

    2001-04-01

    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 4x10{sup 17}/cm{sup 3} has been achieved in high-resistivity FZ silicon with our HTLT technology. With the standard HTLT technology, the original high resistivity of FZ silicon will be retained. However, the controlled introduction of thermal donors (TD) with a concentration higher than the original shallow doping impurity can be achieved with a process slightly altered from the standard HTLT technology (HTLT-TD). Detectors made by both technologies (HTLT and HTLT-TD) have been found to be advantageous in radiation hardness to gamma and proton irradiation, in terms of detector full depletion voltage degradation, as compared to the control samples. In fact, these detectors are insensitive to gamma irradiation up to 600 Mrad and more tolerant by at least a factor of two to proton irradiation and the following reverse annealing. However, there is little improvement in radiation hardness to neutron irradiation, which has been attributed to the nature of neutron-induced damage that is dominated by extended defects or defect clusters. Microscopic measurements (I-DLTS) have also been made on control and HTLT samples and will be compared and presented.

  20. Effect of UV-radiation on track etch parameters of CR-39 plastic track detectors

    International Nuclear Information System (INIS)

    CR-39 track detectors have been irradiated with 239Pu source at nuclear physics laboratory B.H.U. Varanasi, to investigate the track recording properties of the detector. The bulk etch rate is determined by measuring the change in thickness before and after etching, and track etch rate is determined by measuring the change in track length. Other track parameters such as diameter and sensitivity of the plastic detector are also determined. Another set of CR-39 plastic detector is irradiated by 239Pu source and exposed by UV-radiation after irradiation to see the effect of UV-rays on track etches parameters. All detectors were etched in 6.25 N NaOH solution at different temperatures for different hours and all track parameters are measured by optical microscope (Olympus BH-2, magnification 600x). After etching in 6.25 N NaOH solution we see that bulk etch rate, track etch rate and track diameter increased in the case of UV-radiation exposed CR-39 plastics detectors. (author)

  1. Intercomparison of luminescence detectors for space radiation dosimetry within Proton-ICCHIBAN experiments

    Science.gov (United States)

    Uchihori, Yukio; Ploc, Ondrej; Yasuda, Nakahiro; Berger, Thomas; Hajek, Michael; Kodaira, Satoshi; Benton, Eric; Ambrozova, Iva; Kitamura, Hisashi

    2012-07-01

    Luminescence detectors for space radiation dosimetry are frequently used to estimate personal and environmental doses in the International Space Station and other space vehicles. Detector responses for cosmic rays and their secondaries were investigated for a long time and it is well-known that luminescence detectors have dependencies of response on LET (Linear Energy Transfer). Some of luminescence detectors show over-response to gamma rays (used for routine calibration) and others have similar responses to gamma rays. But, because of lack of sufficient and reliable calibration data in the low LET region (about 1 keV/μm), it is the responses of these detectors at LET is poorly known. Protons make up the dominant portion of the fluence from space radiation, so the LET region corresponding to energetic protons must be characterized very well. For that purpose, calibration and intercomparison experiments were performed using relatively low energy (30 to 80 MeV) proton beams at the National Institute of Radiological Sciences, Chiba, Japan. In this paper, the results of these intercomparison experiments, including high energy protons and light ions, are reported and illustrate the response of luminescence detectors in the low LET region. This research will help improve our understanding of space dosimeters and reliable dose measurement for astronauts and cosmonauts in low earth orbit.

  2. Comparison of cosmic rays radiation detectors on-board commercial jet aircraft

    International Nuclear Information System (INIS)

    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. (authors)

  3. Scintillation characteristics of phosphich-detector for detection of beta- and gamma-radiations

    CERN Document Server

    Ananenko, A A; Gavrilyuk, V

    2002-01-01

    The results of the study on the influence of individual peculiarities of the compound scintillation detector structure on the value and stability of the light yield by the gamma- and beta-radiation combined registration are presented. The phosphich detector is manufactured from the sodium iodide monocrystal, activated by thallium, and the scintillation plastic on the polystyrol basis. The comparison of the experimental results with the mathematical modeling data revealed certain regularities of the process of forming the phosphich detector light signal. The recommendations are worked out by means whereof the following characteristics of the scintillation unit: the light yield and its stability, amplitude resolution and the peak-to-valley ratio by the gamma- and beta-radiation registration were improved

  4. Performance of the transition radiation detector of the PAMELA space mission

    CERN Document Server

    Ambriola, M

    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 Si-W imaging calorimeter. The TRD is composed of 9 planes of straw tubes, interleaved with carbon fiber radiators. A prototype of the detector has been exposed to particle beams of electrons, pions and muons of various momenta at the CERN-PS and SPS accelerator facilities. In addition a dedicated Monte Carlo code has been developed to simulate the detector. Here we illustrate both simulation results and experimental data analysis procedures and we will discuss the estimated TRD performance. (15 refs).

  5. High-resolution texture imaging with hard synchrotron radiation in the moving area detector technique

    CERN Document Server

    Wcislak, L; Klein, H; Garbe, U; Schneider, J R

    2003-01-01

    The orientation distribution of crystallites in polycrystalline materials (called texture) is usually measured by polycrystal X-ray diffraction by 'step-scanning' the sample in angular intervals in the order of 1 deg. This technique is not suited to fully exploit the low angular divergence of hard synchrotron radiation in the order of 'milliradian'. Hence, step-scanning was replaced by a continuous 'sweeping' technique using a continuously shifted area detector. In order to avoid overlapping from different reflections (hkl) a Bragg-angle slit was introduced. The 'moving-detector' technique can be applied to obtain images of orientation as well as of location distributions of crystallites in polycrystalline samples. It is suitable for imaging continuous 'orientation density' distribution functions as well as of 'grain-resolved' textures. The excellent features of high-energy synchrotron radiation combined with the moving area detector technique will be illustrated with several examples including very sharp def...

  6. Low-cost cadmium zinc telluride radiation detectors based on electron-transport-only designs

    International Nuclear Information System (INIS)

    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

  7. Fabrication of radiation detector using PbI{sub 2} crystal

    Energy Technology Data Exchange (ETDEWEB)

    Shoji, T.; Sakamoto, K.; Ohba, K.; Suehiro, T.; Hiratate, Y. [Tohoku Inst. of Tech., Sendai (Japan)

    1996-07-01

    In this paper, we will discuss the PbI{sub 2} radiation detector fabricated from a crystal grown by the zone melting method and by the vapor phase method, together with characteristics of the crystal obtained by a XPS analyzer. (J.P.N.)

  8. Radiation detectors at the future p-p collision rings (LHC/SSC)

    International Nuclear Information System (INIS)

    This lesson is about the technology of future proton collider detectors (conception, realization and use) and about the difficulties encountered (repetition ratio, data quantity and radiation problem). After 3-4 research years, many solutions have been found and are presented

  9. Low-cost cadmium zinc telluride radiation detectors based on electron-transport-only designs

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Characteristics of fabricated si PIN-type radiation detectors on cooling temperature

    Science.gov (United States)

    Kim, Han Soo; Jeong, Manhee; Kim, Young Soo; Lee, Dong Hun; Cho, Seung Yeon; Ha, Jang Ho

    2015-06-01

    Si PIN photodiode radiation detectors with three different active areas (3×3 mm2, 5×5 mm2, and 10×10 mm2) were designed and fabricated at the Korea Atomic Energy Research Institute (KAERI) for low energy X- and gamma-ray detection. In Si-based semiconductor radiation detectors, one of the noise sources is thermal noise, which degrades their energy resolution performance. In this study, the temperature effects on the energy resolution were investigated using a 3×3 mm2 active area PIN photodiode radiation detector using a Thermoelectric Module (TEM) from room temperature to -23 °C. Energy resolutions from 25 keV auger electrons to 81 keV gamma-ray from a Ba-133 calibration source were measured and compared at every 10 °C interval. At -23 °C, energy resolutions were improved by 15.6% at 25 keV, 4.0% at 31 keV, and 1.2% at 81 keV in comparison with resolutions at room temperature. CsI(Tl)/PIN photodiode radiation detectors were also fabricated for relatively high energy gamma-ray detection. Energy resolutions for Cs-137, Co-60, and Na-22 sources were measured and compared with the spectral responsivity.

  11. Dead regions and electric thickness in the CdTe(Cl) radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Hirasawa, Masahiko [National Inst. of Radiological Sciences, Division of Radiation Research, Anagawa, Chiba (Japan)

    2001-09-01

    The studies suggested that low resistivity (approximately 10{sup -1}{omega} cm) granular regions were distributed in high resistivity (approximately 10{sup 9} {omega} cm) CdTe(Cl). The existence and influence of these low resistivity regions in the radiation detector made of high resistivity CdTe(Cl) are examined by experiments, numerical simulations and analytical calculations in the present paper. (author)

  12. Gas-Monitor Detector for Intense and Pulsed VUV/EUV Free-Electron Laser Radiation

    Science.gov (United States)

    Sorokin, A. A.; Bobashev, S. V.; Feldhaus, J.; Gerth, Ch.; Gottwald, A.; Hahn, U.; Kroth, U.; Richter, M.; Shmaenok, L. A.; Steeg, B.; Tiedtke, K.; Treusch, R.

    2004-05-01

    In the framework of current developments of new powerful VUV and EUV radiation sources, like VUV free-electron-lasers or EUV plasma sources for 13-nm lithography, we developed a gas-monitor detector in order to measure the photon flux of highly intense and extremely pulsed VUV and EUV radiation in absolute terms. The device is based on atomic photoionization of a rare gas at low particle density. Therefore, it is free of degradation and almost transparent, which allows the detector to be used as a continuously working beam-intensity monitor. The extended dynamic range of the detector allowed its calibration with relative standard uncertainties of 4% in the Radiometry Laboratory of the Physikalisch-Technische Bundesanstalt at the electron-storage ring BESSY II in Berlin using spectrally dispersed synchrotron radiation at low photon intensities and its utilization for absolute photon flux measurements of high power sources. In the present contribution, we describe the design of the detector and its application for the characterization of VUV free-electron-laser radiation at the TESLA test facility in Hamburg. By first pulse resolved measurements, a peak power of more than 100 MW at a wavelength of 87 nm was detected.

  13. Study of planar pixel sensors hardener to radiations for the upgrade of the ATLAS vertex detector

    International Nuclear Information System (INIS)

    In this work, we present a study, using TCAD (Technology Computer-Assisted Design) simulation, of the possible methods of designing planar pixel sensors by reducing their inactive area and improving their radiation hardness for use in the Insertable B-Layer (IBL) project and for SLHC upgrade phase for the ATLAS experiment. Different physical models available have been studied to develop a coherent model of radiation damage in silicon that can be used to predict silicon pixel sensor behavior after exposure to radiation. The Multi-Guard Ring Structure, a protection structure used in pixel sensor design was studied to obtain guidelines for the reduction of inactive edges detrimental to detector operation while keeping a good sensor behavior through its lifetime in the ATLAS detector. A campaign of measurement of the sensor process parameters and electrical behavior to validate and calibrate the TCAD simulation models and results are also presented. A model for diode charge collection in highly irradiated environment was developed to explain the high charge collection observed in highly irradiated devices. A simple planar pixel sensor digitization model to be used in test beam and full detector system is detailed. It allows for easy comparison between experimental data and prediction by the various radiation damage models available. The digitizer has been validated using test beam data for unirradiated sensors and can be used to produce the first full scale simulation of the ATLAS detector with the IBL that include sensor effects such as slim edge and thinning of the sensor. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

    The paper reviews measurements of the radiation tolerance of CVD diamond for irradiation with 24 GeV/c protons, 300 MeV/c pions and 1 MeV 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 outcome from the model shows that for tracker applications this drawback is at least partly counterbalanced by a narrowing of the distribution curve of the charge signal. In addition, we observed after proton irradiation at the charge signal spectrum a decrease of the number of small signals. As a result, the efficiency of a CVD diamond tracker is less affected by irradiation than the mean charge signal.

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

    CERN Document Server

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

    2000-01-01

    The paper reviews measurements of the radiation tolerance of CVD diamond for irradiation with 24 GeV/c protons, 300 MeV/c pions and 1 MeV 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 outcome from the model shows that for tracker applications this drawback is at least partly counterbalanced by a narrowing of the distribution curve of the charge signal. In addition, we observed after proton irradiation at the charge signal spectrum a decrease of the number of small signals. As a result, the efficiency of a CVD diamond tracker is less affected by irradiation than the mean charge signal. (11 refs).

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

    International Nuclear Information System (INIS)

    The paper reviews measurements of the radiation tolerance of CVD diamond for irradiation with 24 GeV/c protons, 300 MeV/c pions and 1 MeV 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 outcome from the model shows that for tracker applications this drawback is at least partly counterbalanced by a narrowing of the distribution curve of the charge signal. In addition, we observed after proton irradiation at the charge signal spectrum a decrease of the number of small signals. As a result, the efficiency of a CVD diamond tracker is less affected by irradiation than the mean charge signal

  17. Radiation hard avalanche photodiodes for the CMS detector

    CERN Document Server

    Antunovic, Z; Deiters, K; Godinovic, N; Ingram, Q; Kuznetsov, A; Musienko, Y; Puljak, I; Renker, D; Reucroft, S; Rusack, R; Sakhelashvili, T M; Singovsky, A V; Soric, I; Swain, J

    2005-01-01

    The avalanche photodiodes, developed by Hamamatsu Photonics in collaboration with CMS, which are to be used to read out the lead tungstate crystals in the barrel part of the CMS electromagnetic calorimeter, are described. The procedures taken to ensure their long-term reliability in the radiation environment expected in CMS are outlined, as well as the studies made to verify the very high reliability required.

  18. Radiation Hard Avalanche Photo-Diodes for the CMS detector

    CERN Document Server

    Antunovic, Z; Deiters, K; Godinovic, N; Ingram, Q; Kuznetsov, A; Musienko, Y; Puljak, I; Reucroft, S; Rusack, R W; Sakhelashvili, T M; Singovsky, A V; Soric, I; Swain, J D

    2003-01-01

    The avalanche photo-diodes, developed by Hamamatsu Photonics in collaboration with CMS, which are to be used to read out the lead tungstate crystals in the barrel part of the CMS electromagnetic calorimeter, are described. The procedures taken to ensure their long term reliability in the radiation environment expected in CMS are outlined, as well as the studies made to verify the very high reliability required.

  19. Radiation dosimetry using junction field-effect transistor detectors

    International Nuclear Information System (INIS)

    The use of junction field effect transistors (JFET) has been studied by connecting them in a bridge circuit. With a suitable back-up circuit, it was possible to measure doses as well as dose-rates. It was possible to alter the sensitivity of the JFET bridge by varying the biasing components of the JFET. Easy temperature compensation was also possible. However, response of the JFET to radiation showed energy dependency similar to that of semiconductor diodes. (author)

  20. BEGe detector response to alpha and beta-radiation near its p+ electrode

    International Nuclear Information System (INIS)

    In Phase II of the GERDA (Germanium Detector Array) experiment Broad Energy Germanium (BEGe) detectors will continue the search for the neutrinoless double beta decay (0νββ) of 76Ge. The main feature of these detectors is their small p+ electrode used for signal read-out. Due to the thin dead layer of the p+ contact, surface events close to this electrode represent a potential background for the search of 0νββ. A study was conducted to determine the response of the detector to alpha and beta-radiation using movable collimated sources within a custom-build cryostat. Preliminary results of this study and a possible method to discriminate these events will be presented.

  1. Calibration of modified Liulin detector for cosmic radiation measurements on-board aircraft

    International Nuclear Information System (INIS)

    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. (authors)

  2. Radiation detectors fabricated on high-purity GaAs epitaxial materials

    Science.gov (United States)

    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.

  3. Investigation of GEM-Micromegas detector on X-ray beam of synchrotron radiation

    Science.gov (United States)

    Zhang, Yu-Lian; Qi, Hui-Rong; Hu, Bi-Tao; Fan, Sheng-Nan; Wang, Bo; Liu, Mei; Zhang, Jian; Liu, Rong-Guang; Chang, Guang-Cai; Liu, Peng; Ouyang, Qun; Chen, Yuan-Bo; Yi, Fu-Ting

    2014-04-01

    To reduce the discharge of the standard bulk Micromegas and GEM detectors, a GEM-Micromegas detector was developed at the Institute of High Energy Physics. Taking into account the advantages of the two detectors, one GEM foil was set as a preamplifier on the mesh of Micromegas in the structure and the GEM preamplification decreased the working voltage of Micromegas to significantly reduce the effect of the discharge. At the same gain, the spark probability of the GEM-Micromegas detector can be reduced to a factor 0.01 compared to the standard Micromegas detector, and an even higher gain could be obtained. This paper describes the performance of the X-ray beam detector that was studied at 1W2B Laboratory of Beijing Synchrotron Radiation Facility. Finally, the result of the energy resolution under various X-ray energies was given in different working gases. This indicates that the GEM-Micromegas detector has an energy response capability in an energy range from 6 keV to 20 keV and it could work better than the standard bulk-Micromegas.

  4. Review of Physics and Monte Carlo Techniques as Relevant to a Cryogenic, Phonon and Ionization Readout, Radiation-Detector

    CERN Document Server

    Leman, S W

    2011-01-01

    This review discusses detector physics and Monte Carlo techniques for cryogenic, radiation detectors that utilize combined phonon and ionization readout. Particular focus is placed on instrumentation that is used in the Cryogenic Dark Matter Search detectors however the discussion is quite general and includes phonon and charge transport physics relevant at low temperatures. Sufficient tutorials and physics references are provided such that an interested reader can jump right into a detector Monte Carlo campaign.

  5. Role of fuel chemical properties on combustor radiative heat load

    Science.gov (United States)

    Rosfjord, T. J.

    1984-01-01

    In an attempt to rigorously study the fuel chemical property influence on combustor radiative heat load, UTRC has conducted an experimental program using 25 test fuels. The burner was a 12.7-cm dia cylindrical device fueled by a single pressure-atomizing injector. Fuel physical properties were de-emphasized by selecting injectors which produced highly-atomized, and hence rapidly-vaporizing sprays. The fuels were specified to cover the following wide ranges of chemical properties: hydrogen, 9.1 to 15- (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. They included standard fuels, specialty products and fuel blends. Fuel naphthalene content exhibited the strongest influence on radiation of the chemical properties investigated. Smoke point was a good global indicator of radiation severity.

  6. Application of synchrotron radiation in chemical dynamics

    International Nuclear Information System (INIS)

    In October 1992, funding was approved to begin construction of a beamline and two end stations to support chemical dynamics experiments at LBL's Advanced Light Source (ALS). This workshop was organized to develop specifications and plans and to select a working team to design and supervise the construction project. Target date for starting the experiments is January 1995. Conclusions of the workshop and representative experiments proposed in earlier workshops to form the basis for beamline plans and end-station designs are summarized in this report. 6 figs

  7. Application of synchrotron radiation in chemical dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Heimann, P.; Koike, M.; Kung, A.H.; Ng, C.Y.; White, M.G.; Wodtke, A.

    1993-05-01

    In October 1992, funding was approved to begin construction of a beamline and two end stations to support chemical dynamics experiments at LBL's Advanced Light Source (ALS). This workshop was organized to develop specifications and plans and to select a working team to design and supervise the construction project. Target date for starting the experiments is January 1995. Conclusions of the workshop and representative experiments proposed in earlier workshops to form the basis for beamline plans and end-station designs are summarized in this report. 6 figs.

  8. Application of synchrotron radiation in chemical dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Heimann, P.; Koike, M.; Kung, A.H.; Ng, C.Y.; White, M.G.; Wodtke, A.

    1993-05-01

    In October 1992, funding was approved to begin construction of a beamline and two end stations to support chemical dynamics experiments at LBL`s Advanced Light Source (ALS). This workshop was organized to develop specifications and plans and to select a working team to design and supervise the construction project. Target date for starting the experiments is January 1995. Conclusions of the workshop and representative experiments proposed in earlier workshops to form the basis for beamline plans and end-station designs are summarized in this report. 6 figs.

  9. Chemical and radiation carcinogenesis. Progress report

    International Nuclear Information System (INIS)

    Gamma radiation, as a quantitative perturbation reference, has been related to oxygen toxicity as the unavoidable background risk due to living in an oxygen atmosphere. The basic mechanisms shared by gamma irradiation and oxygen toxicity have been studied. The response to these two perturbations has been characterized at the molecular level through DNA chemistry and monoclonal antibodies, and by cellular biological responses. The investigation of cellular responses is being extended to the molecular level through a study of alteration of gene arrangement and gene expression. Concentration has been on the study of the involvement of the evolutionally conserved repetitive DNA sequences shared by hamster and man. Such sequences were found and some have been isolated in plasmids. Two cellular systems were chosen for investigation, the embryonic/adult mesenchymal system and the hematopoietic tissues system. Concentration has been on the isolation, properties, and response to perturbation of the progenitor cells and the stem cell populations

  10. Proton irradiation of stem cells: Radiation damage and chemical radioprotection

    Science.gov (United States)

    Riley, R. C.; Montour, J. L.; Gurney, C. W.

    1972-01-01

    Effects of high energy protons on erythropoietic stem cells and radioprotection by chemicals were investigated in NASA Space Radiation Effects Laboratory. The effects of a parallel beam of 600 MeV protons. The fluence, when converted to dose, were referenced to the synchrocyclotron beam monitors which were then used to administer radiation exposures. Mice were given graded doses to 300 rads to determine dose-response curve. Other mice received saline, AET, or 5-hydroxytryptamine 10 to 15 minutes before exposure.

  11. About chemical composition of the primary cosmic radiation at ultra-high energies

    CERN Document Server

    Dedenko, T M Roganova L G; Fedorova, G F; Knurenko, S P; Makarov, I T; Podgrudkov, D A; Pravdin, M I; Sleptzov, I Ye

    2009-01-01

    The fluxes of electrons, positrons, gammas, Cherenkov photons and muons in individual extensive air showers induced by the primary protons and helium, oxygen and iron nuclei at the level of observation have been estimated with help of the code CORSICA 6.616. The comparison show that the values of the function Xi**2 per one degree of freedom changes from 1.1 for iron nuclei to 0.9 for primary protons. As this difference is small all readings of detectors of the Vavilov-Cherenkov radiation have been used. At last, readings of underground detectors of muons with energies above 1 GeV have been exploited to make definite conclusion about chemical composition.

  12. Analysis of Surface Chemistry and Detector Performance of Chemically Process CdZnTe crystals

    Energy Technology Data Exchange (ETDEWEB)

    HOSSAIN, A.; Yang, G.; Sutton, J.; Zergaw, T.; Babalola, O. S.; Bolotnikov, A. E.; Camarda. ZG. S.; Gul, R.; Roy, U. N., and James, R. B.

    2015-10-05

    The goal is to produce non-conductive smooth surfaces for fabricating low-noise and high-efficiency CdZnTe devices for gamma spectroscopy. Sample preparation and results are discussed. The researachers demonstrated various bulk defects (e.g., dislocations and sub-grain boundaries) and surface defects, and examined their effects on the performance of detectors. A comparison study was made between two chemical etchants to produce non-conductive smooth surfaces. A mixture of bromine and hydrogen peroxide proved more effective than conventional bromine etchant. Both energy resolution and detection efficiency of CZT planar detectors were noticeably increased after processing the detector crystals using improved chemical etchant and processing methods.

  13. Radiation tolerance of CVD diamond detectors for pions and protons

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Berdermann, E.; Bergonzo, P.; Bertuccio, G.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; D' Angelo, P.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Hallewell, G.; Han, S.; Hartjes, F. E-mail: f.hartjes@nikhef.nl; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Kass, R.; Koeth, T.; Krammer, M.; Logiudice, A.; Lu, R.; Mac Lynne, L.; Manfredotti, C.; Meier, D.; Mishina, M.; Moroni, L.; Noomen, J.; Oh, A.; Pan, L.S.; Pernicka, M.; Peitz, A.; Perera, L.; Pirollo, S.; Procario, M.; Riester, J.L.; Roe, S.; Rousseau, L.; Rudge, A.; Russ, J.; Sala, S.; Sampietro, M.; Schnetzer, S.; Sciortino, S.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trischuk, W.; Tromson, D.; Vittone, E.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; Wetstein, M.; White, C.; Zeuner, W.; Zoeller, M

    2002-01-11

    The paper gives new results on the radiation tolerance of CVD diamond for irradiation with 300 MeV/c pions and 24 GeV/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 model show that for tracker applications this drawback is at least partly counterbalanced by a narrowing of the distribution curve of the charge signal. As a result, the efficiency of a CVD diamond tracker is less affected by irradiation than the mean charge signal.

  14. Radiation tolerance of CVD diamond detectors for pions and protons

    International Nuclear Information System (INIS)

    The paper gives new results on the radiation tolerance of CVD diamond for irradiation with 300 MeV/c pions and 24 GeV/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 model show that for tracker applications this drawback is at least partly counterbalanced by a narrowing of the distribution curve of the charge signal. As a result, the efficiency of a CVD diamond tracker is less affected by irradiation than the mean charge signal

  15. Human Genetic Marker for Resistance to Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    DR. Howard B. Lieberman

    2001-05-11

    TO characterize the human HRDAD9 gene and evaluate its potential as a biomarker to predict susceptibility to the deleterious health effects potentially caused by exposure to radiations or chemicals present at DOE hazardous waste cleanup sites. HRAD9 is a human gene that is highly conserved throughout evolution. Related genes have been isolated from yeasts and mice, underscoring its biological significance. Most of our previous work involved characterization of the yeast gene cognate, wherein it was determined that the corresponding protein plays a significant role in promoting resistance of cells to radiations and chemicals, and in particular, controlling cell growth in response to DNA damage.

  16. Human Genetic Marker for Resistance to Radiation and Chemicals

    International Nuclear Information System (INIS)

    TO characterize the human HRDAD9 gene and evaluate its potential as a biomarker to predict susceptibility to the deleterious health effects potentially caused by exposure to radiations or chemicals present at DOE hazardous waste cleanup sites. HRAD9 is a human gene that is highly conserved throughout evolution. Related genes have been isolated from yeasts and mice, underscoring its biological significance. Most of our previous work involved characterization of the yeast gene cognate, wherein it was determined that the corresponding protein plays a significant role in promoting resistance of cells to radiations and chemicals, and in particular, controlling cell growth in response to DNA damage

  17. Development of a plasma panel radiation detector: recent progress and key issues

    CERN Document Server

    Silver, Yiftah; Beene, James R; Benhammou, Yan; Ben-Moshe, Meny; Chapman, J W; Dai, Tiesheng; Etzion, Erez; Ferretti, Claudio; Guttman, Nir; Friedman, Peter S; Levin, Daniel S; Ritt, S; Varner, Robert L; Weaverdyck, Curtis; Zhou, Bing

    2012-01-01

    A radiation detector based on plasma display panel technology, which is the principal component of plasma television displays is presented. Plasma Panel Sensor (PPS) technology is a variant of micropattern gas radiation detectors. The PPS is conceived as an array of sealed plasma discharge gas cells which can be used for fast response (O(5ns) per pixel), high spatial resolution detection (pixel pitch can be less than 100 micrometer) of ionizing and minimum ionizing particles. The PPS is assembled from non-reactive, intrinsically radiation-hard materials: glass substrates, metal electrodes and inert gas mixtures. We report on the PPS development program, including simulations and design and the first laboratory studies which demonstrate the usage of plasma display panels in measurements of cosmic ray muons, as well as the expansion of experimental results on the detection of betas from radioactive sources.

  18. A single-photon counting 'edge-on' silicon detector for synchrotron radiation mammography

    Energy Technology Data Exchange (ETDEWEB)

    Rigon, L. [INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy)], E-mail: luigi.rigon@ts.infn.it; Arfelli, F. [INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy); Physics Department, University of Trieste, Via Valerio 2, 34127 Trieste (Italy); Astolfo, A. [Physics Department, University of Trieste, Via Valerio 2, 34127 Trieste (Italy); Bergamaschi, A. [Paul Scherrer Institut, PSI 5232 Villigen (Switzerland); Dreossi, D. [INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy); Sincrotrone Trieste SCpA, S.S. 14 km 163.5, 34012 Basovizza (Italy); Longo, R. [INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy); Physics Department, University of Trieste, Via Valerio 2, 34127 Trieste (Italy); Menk, R.-H. [Sincrotrone Trieste SCpA, S.S. 14 km 163.5, 34012 Basovizza (Italy); Schmitt, B. [Paul Scherrer Institut, PSI 5232 Villigen (Switzerland); Vallazza, E. [INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy); Castelli, E. [INFN, Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy); Physics Department, University of Trieste, Via Valerio 2, 34127 Trieste (Italy)

    2009-09-01

    The Phase Imaging for Clinical Application with Silicon detector and Synchrotron radiatiOn (PICASSO) project is developing an 'edge-on' silicon microstrip detector for mammography with synchrotron radiation. The sensor is equipped with a fast single-photon counting electronics based on the Mythen-II application-specific integrated circuit. A first prototype has been assembled and tested at the SYnchrotron Radiation for MEdical Physics (SYRMEP) beamline at Elettra in Trieste, Italy. The first results are presented in this study including evidence of high-rate single-photon counting with negligible losses up to 1.2x10{sup 6} incident photons per pixel per second; spatial resolution consistent with the pixel aperture (0.3 mmx0.05 mm); high-quality imaging of test-objects, obtained with a dose comparable to the one delivered in modern full-field digital mammographic systems.

  19. Optimized digital filtering techniques for radiation detection with HPGe detectors

    CERN Document Server

    Salathe, M

    2015-01-01

    This paper describes state-of-the-art digital filtering techniques that are part of the tool kit GEANA which is used as a fast automatic data validation tool for the GERDA experiment. The discussed filters include a novel, nonlinear correction method for ballistic deficits, which is combined with one of three shaping filters: the pseudo-Gaussian, a modified trapezoidal, or a modified cusp filter. The performance of the filters is demonstrated using a 762 g high purity germanium detector that measures gamma-ray lines from radioactive sources in an energy range between 59 and 2615 keV. The modified cusp filter was found to be most optimal for individual gamma-ray lines. Furthermore, it was observed, that even though, the shaping time that minimizes the energy resolution is energy dependent, the loss in resolution by using a constant shaping time over the entire energy range is small, i.e. less than 32 eV for the pseudo-Gaussian filter. This together with good energy resolutions, e.g. 1.59 keV at 1333 keV, this ...

  20. Study the radiation damage effects in Si microstrip detectors for future HEP experiments

    Science.gov (United States)

    Lalwani, Kavita; Jain, Geetika; Dalal, Ranjeet; Ranjan, Kirti; Bhardwaj, Ashutosh

    2016-07-01

    Silicon (Si) detectors are playing a key role in High Energy Physics (HEP) experiments due to their superior tracking capabilities. In future HEP experiments, like upgrade of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC), CERN, the silicon tracking detectors will be operated in a very intense radiation environment. This leads to both surface and bulk damage in Si detectors, which in turn will affect the operating performance of Si detectors. It is important to complement the measurements of the irradiated Si strip detectors with device simulation, which helps in understanding of both the device behavior and optimizing the design parameters needed for the future Si tracking system. An important ingredient of the device simulation is to develop a radiation damage model incorporating both bulk and surface damage. In this work, a simplified two-trap model is incorporated in device simulation to describe the type-inversion. Further, an extensive simulation of effective doping density as well as electric field profile is carried out at different temperatures for various fluences.

  1. Evaluation of the radiation field in the future circular collider detector

    CERN Document Server

    Besana, Maria Ilaria; Ferrari, Alfredo; Riegler, Werner; Vlachoudis, Vasilis

    2016-01-01

    The radiation load on a detector at a 100 TeV proton-proton collider, that is being investigated within the Future Circular Collider (FCC) study, is presented. A peak luminosity of 30 1034 cm−2s−1 and a total integrated luminosity of 30 ab−1 are assumed for these radiation studies. A first concept of the detector foresees the presence of central and forward sub-detectors that provide acceptance up to |η|=6 inside a magnetic field generated by the combination of a central solenoid and two forward dipoles. This layout has been modelled and relevant fluence and dose distributions have been calculated using the FLUKA Monte Carlo code. Distributions of fluence rates are discussed separately for charged particles, neutrons and pho- tons. Dose and 1 MeV neutron equivalent fluence, for the accumulated integrated luminosity, are presented. The peak values of these quantities in the different sub-detectors are highlighted, in order to define the radiation tolerance requirements for the choice of possible technol...

  2. Ticor-based scintillation detectors for detection of mixed radiation

    CERN Document Server

    Litvinov, L A; Kolner, V B; Ryzhikov, V D; Volkov, V G; Tarasov, V A; Zelenskaya, O V

    2002-01-01

    Detection of mixed radiation of thermal neutrons and gamma-rays have been realized using a new ceramic material based on small-crystalline long-wave scintillator alpha-Al sub 2 O sub 3 :Ti (Ticor) and lithium fluoride. Characteristics are presented for scintillators with Si-PIN-PD type photoreceivers and PMT under sup 2 sup 3 sup 9 Pu alpha-particles, sup 2 sup 0 sup 7 Bi internal conversion electrons,as well as sup 2 sup 4 sup 1 Am and sup 1 sup 3 sup 7 Cs gamma-quanta. Detection efficiency of thermal neutron is estimated for composite materials based on Ticor and lithium fluoride.

  3. The simulation of the LANFOS-H food radiation contamination detector using Geant4 package

    Science.gov (United States)

    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 π 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 γ conversion factor of the detectors-how many γ 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 π non-destructive apparatus.

  4. Modeling of radiation damage recovery in particle detectors based on GaN

    Science.gov (United States)

    Gaubas, E.; Ceponis, T.; Pavlov, J.

    2015-12-01

    The pulsed characteristics of the capacitor-type and PIN diode type detectors based on GaN have been simulated using the dynamic and drift-diffusion models. The drift-diffusion current simulations have been implemented by employing the commercial software package Synopsys TCAD Sentaurus. The bipolar drift regime has been analyzed. The possible internal gain in charge collection through carrier multiplication processes determined by impact ionization has been considered in order to compensate carrier lifetime reduction due to radiation defects introduced into GaN material of detector.

  5. A Leakage Current-based Measurement of the Radiation Damage in the ATLAS Pixel Detector

    CERN Document Server

    Gorelov, Igor; The ATLAS collaboration

    2015-01-01

    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.

  6. A Response of coaxial Ge (Li) detector to the extended source of gamma radiation

    International Nuclear Information System (INIS)

    In measurements of the absolute source strength of extended source of γ radiation, two main limitations on the accuracy are dues to the difficulties in accounting for the self-absorption in the source and for geometrical dependence of detector efficiency. Two problems were separated by introduction of the average only energy dependent efficiency, which lends itself to calculational and experimental determination (to be reported), and the response of coaxial Ge(Li) detector to cylindrical extended source with self-absorption has been developed here to a reduced analytical form convenient gu numerical calculations. (author)

  7. Gamma spectroscopic measurements using the PID350 pixelated CdTe radiation detector

    CERN Document Server

    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.

  8. Radon measurements by etched track detectors applications in radiation protection, earth sciences and the environment

    CERN Document Server

    Durrani, Saeed A

    1997-01-01

    Exposure to radon gas, which is present in the environment naturally, constitutes over half the radiation dose received by the general public annually. At present, the most widely used method of measuring radon concentration levels throughout the world, both in dwellings and in the field, is by etched track detectors - also known as Solid State Nuclear Detectors (SSNTDs). Although this is not only the most widely used method but is also the simplest and the cheapest, yet there is at present no book available on the market globally, devoted exclusively or largely to the methodology of, and deal

  9. The Performance Assessment of the Detector for the Portable Environmental Radiation Distribution Monitoring System with Rapid Nuclide Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Uk Jae; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    The environment radiation distribution monitoring system measures the radiation using a portable detector and display the overall radiation distribution. Bluetooth and RS-232 communications are used for constructing monitoring system. However RS-232 serial communication is known to be more stable than Bluetooth and also it can use the detector's raw data which will be used for getting the activity of each artificial nuclide. In the present study, the detection and communication performance of the developed detector with RS-232 method is assessed by using standard sources for the real application to the urban or rural environment. Assessment of the detector for the portable environmental radiation distribution monitoring system with rapid nuclide recognition was carried out. It was understood that the raw data of detector could be effectively treated by using RS-232 method and the measurement showed a good agreement with the calculation within the relative error of 0.4 % in maximum.

  10. Radiation hardness of the HERA-B double-sided silicon strip detectors

    CERN Document Server

    Bauer, C; Knöpfle, K T; Pugatch, V; Schwingenheuer, B; Abt, I; Dressel, M; Masciocchi, S; Perschke, T; Schaller, S

    2002-01-01

    Irradiation studies of double-sided silicon strip-detectors for the HERA-B experiment have been performed using a setup at a 21 MeV proton beam. A novel method of fluence monitoring has been implemented. The study presented here gives results of a non-uniform irradiation of two HERA-B detector modules built with double-sided detectors made of oxygenated as well as non-oxygenated wafers. The maximum exposed fluence corresponds to about 3x10 sup 1 sup 4 MIP/cm sup 2. The characterization of the detectors was done with a laser and a sup 1 sup 0 sup 6 Ru source. In regions of low-radiation dose, signal over noise ratios of 22 and 16 were measured for n- and p-side, respectively. In the region of maximum fluence, S/N values of approx 17 and approx 15 were obtained at a bias voltage of 450 V for n- and p-strips, respectively. Our measurements establish for both detector types full functionality at fluences varying by two orders of magnitude. Standard and oxygenated detectors do not show any significant difference.

  11. Current applications of semiconductor x-ray detectors in chemical analysis

    International Nuclear Information System (INIS)

    In the last few years, semiconductor detectors have been used as X-ray detectors with great success, and the routine rapid accumulation of X-ray spectra is now possible. This review surveys the historical development of the detectors, the utilisation, and relative merits of various means of exciting the X-radiation from the elements in the sample, and compares the technique with other methods claiming to offer the capability of simultaneous multi-element analysis. It is concluded that it is of average sensitivity, but offers some advantages from its non-destructive nature, and in some cases its ability to offer information about the spatial distribution of elements in a sample. Other types of analysis may also be possible simultaneously. Sample preparation techniques are reviewed, especially techniques of manufacturing thin samples. An appendix contains details of the very wide variety of samples which have been analysed. More than 350 references are included. (auth.)

  12. State and tendencies of chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Papers published in 1978 in the field of chemical protection against ionizing radiation are reviewed. Protection studies in in-vivo and model systems, the biochemical, pharmacological and toxic effects, and modes of action of radioprotective agents are described and the trends in this field of research appreciated. (author)

  13. State and tendencies of chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Papers published in 1979 and 1980 in the field of chemical protection against ionizing radiation are reviewed. Protection studies in in-vivo and model systems, the biochemical, pharmacological and toxic effects, and modes of action of radioprotective agents are described and the trends in this field of research estimated. (author)

  14. Radiation damage in proton-irradiated epitaxial silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Joern

    2009-07-15

    In this work radiation hardness of 75 {mu}m, 100 {mu}m and 150 {mu}m thick epitaxial silicon pad diodes of both standard and oxygenated material was investigated. Damage after 24 GeV/c proton irradiation in a 1MeV neutron equivalent fluence range between 10{sup 14} cm{sup -2} and 10{sup 16} cm{sup -2} was studied and isothermal annealing experiments at 80 C were carried out. Standard CV/IV measurements could be performed up to 4 x 10{sup 15} cm{sup -2}. The volume-normalised reverse current was found to increase linearly with fluence with a slope independent of the thickness and impurity concentration. However, due to large fluctuations the fluences had to be renormalised using the current-related damage parameter. Concerning the depletion voltage, nearly all materials remained at a moderate level up to 4 x 10{sup 15} cm{sup -2}. During short-term annealing acceptors annealed out, whereas others were introduced during the long-term annealing. The stable damage was characterised by donor removal at low fluences and fluence-proportional predominant donor introduction for highly irradiated diodes, depending on the oxygen level. No type inversion was observed. Time-resolved measurements with a new 670 nm laser-TCT setup made the determination of the trapping time constant with the charge correction method possible. The results agreed with expectations and showed a linear increase of trapping probability with fluence. The electric field exhibited a double peak structure in highly irradiated diodes. Charge collection efficiency measurements with {alpha}-particles were independent of oxygen concentration, but showed an improved efficiency for thinner diodes. A comparison to simulation revealed systematic discrepancies. A non-constant trapping time parameter was proposed as possible solution. (orig.)

  15. Radiation damage in proton-irradiated epitaxial silicon detectors

    International Nuclear Information System (INIS)

    In this work radiation hardness of 75 μm, 100 μm and 150 μm thick epitaxial silicon pad diodes of both standard and oxygenated material was investigated. Damage after 24 GeV/c proton irradiation in a 1MeV neutron equivalent fluence range between 1014 cm-2 and 1016 cm-2 was studied and isothermal annealing experiments at 80 C were carried out. Standard CV/IV measurements could be performed up to 4 x 1015 cm-2. The volume-normalised reverse current was found to increase linearly with fluence with a slope independent of the thickness and impurity concentration. However, due to large fluctuations the fluences had to be renormalised using the current-related damage parameter. Concerning the depletion voltage, nearly all materials remained at a moderate level up to 4 x 1015 cm-2. During short-term annealing acceptors annealed out, whereas others were introduced during the long-term annealing. The stable damage was characterised by donor removal at low fluences and fluence-proportional predominant donor introduction for highly irradiated diodes, depending on the oxygen level. No type inversion was observed. Time-resolved measurements with a new 670 nm laser-TCT setup made the determination of the trapping time constant with the charge correction method possible. The results agreed with expectations and showed a linear increase of trapping probability with fluence. The electric field exhibited a double peak structure in highly irradiated diodes. Charge collection efficiency measurements with α-particles were independent of oxygen concentration, but showed an improved efficiency for thinner diodes. A comparison to simulation revealed systematic discrepancies. A non-constant trapping time parameter was proposed as possible solution. (orig.)

  16. Study of LiF:Mg,Cu,P TL detectors for individual monitoring for weakly penetrating radiations

    DEFF Research Database (Denmark)

    Christensen, P.

    1993-01-01

    The results are described of a study of three commercially available LiF:Mg,Cu,P TL materials aiming at using this phosphor for individual monitoring for weakly penetrating radiations. Due to the high radiation sensitivity of the material it is suitable for application as thin detectors which are...... necessary for monitoring weakly penetrating radiations. Furthermore, the good energy response characteristics of the material for exposure to photons makes it also attractive for monitoring strongly penetrating radiations. Results are given on glow curve analyses of the LiF:Mg,Cu,P TL phosphor and data are...... presented on a number of important dosimetric characteristics of thin detectors prepared from the material, both commercially available detectors and samples prepared in the laboratory. In particular, annealing requirements, and response characteristics of the detectors to beta and photon radiation were...

  17. High-speed, multi-channel detector readout electronics for fast radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, Wolfgang

    2012-06-22

    In this project, we are developing a high speed digital spectrometer that a) captures detector waveforms at rates up to 500 MSPS b) has upgraded event data acquisition with additional data buffers for zero dead time operation c) moves energy calculations to the FPGA to increase spectrometer throughput in fast scintillator applications d) uses a streamlined architecture and high speed data interface for even faster readout to the host PC These features are in addition to the standard functions in our existing spectrometers such as digitization, programmable trigger and energy filters, pileup inspection, data acquisition with energy and time stamps, MCA histograms, and run statistics. In Phase I, we upgraded one of our existing spectrometer designs to demonstrate the key principle of fast waveform capture using a 500 MSPS, 12 bit ADC and a Xilinx Virtex-4 FPGA. This upgraded spectrometer, named P500, performed well in initial tests of energy resolution, pulse shape analysis, and timing measurements, thus achieving item (a) above. In Phase II, we are revising the P500 to build a commercial prototype with the improvements listed in items (b)-(d). As described in the previous report, two devices were built to pursue this goal, named the Pixie-500 and the Pixie-500 Express. The Pixie-500 has only minor improvements from the Phase I prototype and is intended as an early commercial product (its production and part of its development were funded outside the SBIR). It also allows testing of the ADC performance in real applications.The Pixie-500 Express (or Pixie-500e) includes all of the improvements (b)-(d). At the end of Phase II of the project, we have tested and debugged the hardware, firmware and software of the Pixie-500 Express prototype boards delivered 12/3/2010. This proved substantially more complex than anticipated. At the time of writing, all hardware bugs have been fixed, the PCI Express interface is working, the SDRAM has been successfully tested and the SHARC

  18. Characteristics of fabricated SiC radiation detectors for fast neutron detection

    International Nuclear Information System (INIS)

    Silicon carbide (SiC) is a promising material for neutron detection at harsh environments because of its capability to withstand strong radiation fields and high temperatures. Two PIN-type SiC semiconductor neutron detectors, which can be used for nuclear power plant (NPP) applications, such as in-core reactor neutron flux monitoring and measurement, were designed and fabricated. As a preliminary test, MCNPX simulations were performed to estimate reaction probabilities with respect to neutron energies. In the experiment, I-V curves were measured to confirm the diode characteristic of the detectors, and pulse height spectra were measured for neutron responses by using a 252Cf neutron source at KRISS (Korea Research Institute of Standards and Science), and a Tandem accelerator at KIGAM (Korea Institute of Geoscience and Mineral Resources). The neutron counts of the detector were linearly increased as the incident neutron flux got larger.

  19. LHCb: The Performance and Radiation Hardness of the Outer Tracker Detector for LHCb

    CERN Multimedia

    Färber, C

    2012-01-01

    The LHC bexperiment is designed to study B-decays at the LHC. It is crucial to accurately and efficiently detect the charged decay particles in the high-density particle environment of the LHC. For this, the Outer Tracker (OT) has been constructed, consisting of 53,760 straw tubes, covering in total an area of 360 m2 of double layers. At the time of the conference, the detector will have operated under nominal LHC conditions for a period of about 2 years, corresponding to an integrated luminosity of approximately 2.5 fb$^{-1}$ . The performance of the detector will be discussed in terms of high voltage stability, noise rate, single hit efficiency and resolution. Finally, first results on the radiation tolerance of this sensitive gas detector will be shown, after having received a total dose corresponding to about 100 mC/cm in the hottest region.

  20. Feasibility study for the use of PADC as a radiation detector for living cell cultures

    CERN Document Server

    Meesen, G; Gestel, S V; Oostveldt, P V

    1999-01-01

    In the framework of an ESA project, a microbiological experiment in space is planned. In this experiment a cell culture will be exposed to cosmic radiation onboard a spacecraft. Because the living cell culture will be directly on a nuclear track detector stack, this detector will be submitted to a different environment than normally used. The temperature will be 37 deg. C and the culture will be in a biological growth medium. Tests have been conducted to assess the possible use of PADC in these conditions. For this, a series of alpha irradiated detectors have been exposed for different periods of time (up to 1 month) to these 'biological' conditions. The radiological properties as well as the mechanical properties (swelling...) have been investigated. Results show no influence of the biological environment on the PADC, which makes it useable under these circumstances.

  1. A transition radiation detector interleaved with low-density targets for the NOE experiment

    CERN Document Server

    Alexandrov, K V; Bernardini, P; Brigida, M; Campana, D; Candela, A M; Caruso, R; Cassese, F; Ceres, A; D'Aquino, B; De Cataldo, G; De Mitri, I; Di Credico, A; Favuzzi, C; Fusco, P; Gargano, F; Giglietto, N; Giordano, F; Grillo, A; Guarino, F; Gustavino, C; Lamanna, E; Lauro, A; Leone, A; Loparco, F; Mancarella, G; Martello, D; Mazziotta, M N; Mikheyev, S P; Mongelli, M; Osteria, G; Palladino, Vittorio; Passeggio, G; Perchiazzi, M; Pontoniere, G; Rainó, A; Rocco, R; Romanucci, E; Rubizzo, U; Sacchetti, A; Scapparone, E; Spinelli, P; Tikhomirov, V; Vaccina, A; Vanzanella, E; Weber, M

    2001-01-01

    The NOE Collaboration has proposed a transition radiation detector (TRD) interleaved with marble targets to tag the electron decay channel of tau leptons produced by nu /sub tau /, eventually originated by nu /sub mu / oscillations in a long base line experiment. A reduced scale TRD detector prototype has been built and exposed to an electron/pion beam at the CERN PS. Discrimination capabilities between electrons and both charged and neutral pions, representing the main source of background for our measurement, have been determined obtaining rejection factors of the order of the tenth of percent for charged pions, and of a few percent for the neutral pion, matching the experiment requirements. The capabilities of this detector to measure the energy released by particles that start showering inside the targets are shown. A momentum resolution sigma /sub p//P

  2. Improved charge collection of the buried p-i-n a-Si:H radiation detectors

    International Nuclear Information System (INIS)

    Charge collection in hydrogenated amorphous silicon (a-Si:H) radiation detectors is improved for high LET particle detection by adding thin intrinsic layers to the usual p-i-n structure. This buried p-i-n structure enables us to apply higher bias and the electric field is enhanced. When irradiated by 5.8 MeV α particles, the 5.7 μm thick buried p-i-n detector with bias 300V gives a signal size of 60,000 electrons, compared to about 20,000 electrons with the simple p-i-n detectors. The improved charge collection in the new structure is discussed. The capability of tailoring the field profile by doping a-Si:H opens a way to some interesting device structures. 17 refs., 7 figs

  3. GEANT Simulation of the Radiation Dose for the Inner Tracking System of the ALICE Detector

    CERN Document Server

    Barbera, R; CERN. Geneva; Palmeri, A; Pappalardo, G S; Riggi, F; Badalà, A

    1999-01-01

    A full GEANT simulation of the radiation dose expected for the Inner Tracking System (ITS) of the ALICE detector at the Large Hadron Collider has been carried out. Heavy-ion collision events at a c.m. energy of 6 TeV/nucleon have been generated through the HIJING 1.35 event generator and injected into the GEANT software replica of the ALICE detector, to simulate the planned scenario for the first ten years of data taking of the detector. Several factors contributing to the evaluation of the absorbed dose, including the different ITS implementation options, the effect of the magnetic field, the presence of the beam pipe, the finite size of the interaction point and the front absorber of the muon spectrometer are discussed.

  4. A Study to Improve the Radiation Hardness of Gaseous Detectors for Use at Very High Luminosities

    CERN Multimedia

    2002-01-01

    A two-year project is proposed to study the ageing of gas filled proportional detectors under irradiation. The goal is to obtain experimentally a better understanding of the gas polymerisation processes appearing at high radiation doses, in order to extend the lifetime of detectors well above the MRad region. \\\\ \\\\ The wide range of reported lifetimes is symptomatic of our poor understanding of the ageing process: often, measurements supposedly done under identical conditions result in very different lifetimes.\\\\ \\\\ The aim of this project is, with the knowledge gained, to construct a full scale prototype chamber on which future designs can be based. This will ultimately check the validity of our findings and results under realistic experimental circumstances. \\\\ \\\\ The study of ageing processes in gaseous detectors should commence with the construction of reference chambers.\\\\ \\\\ These chambers will be tested for signs of ageing by examination of the $^5

  5. Integrated High-Rate Transition Radiation Detector and Tracking Chamber for the LHC

    CERN Multimedia

    2002-01-01

    % RD-6 \\\\ \\\\Over the past five years, RD-6 has developed a transition radiation detector and charged particle tracker for high rate operation at LHC. The detector elements are based on C-fibre reinforced kapton straw tubes of 4~mm diameter filled with a Xenon gas mixture. Detailed measurements with and without magnetic field have been performed in test beams, and in particular have demonstrated the possibility of operating straw tubes at very high rate (up to 20~MHz) with accurate drift-time measurement accuracy. A full-scale engineering prototype containing 10~000 straws is presently under assembly and will be accurately measured with a powerful X-ray tube. Integrated front-end electronics with fast readout have been designed and successfully operated in test beam. \\\\ \\\\Finally extensive simulations performed for ATLAS have shown that such a detector will provide powerful pattern recognition, accurate momentum measurements, efficient level-2 triggering and excellent electron identification, even at the highe...

  6. Characterization of the Radiation Field in the FCC-hh Detector

    CERN Document Server

    Besana, Maria Ilaria; Ferrari, Alfredo; Riegler, Werner; Vlachoudis, Vasilis

    2016-01-01

    As part of the post-LHC high-energy program, a study is ongoing to design a new 100 km long hadron collider, which is expected to operate at a centre-of-mass energy of 100 TeV and to accumulate up to 30 ab−1, with a peak instantaneous luminosity that could reach 30 1034cm−2s−1. In this context, the evaluation of the radiation load on the detector is a key step for the choice of materials and technologies. In this contribution, a first detector concept will be presented. At the same time, fluence distributions, relevant for detector occupancy, and accumulated damage on materials and electronics will be shown. The effectiveness of a possible shielding configuration, intended to minimise the background in the muon chambers and tracking stations, will be presented.

  7. Measurement of environmental radiation using medical scintillation detector in well counter system

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Kwang Yeul; Park, Yeon Joon; Kim, Min Jeong; Ham, Eun Hye; Yoon, Ji Yeol; Kim, Hyun in; Min, Jung Hwan; Park, Hoon Hee [Dept. of Radiological Technology, Shingu College, Sungnam (Korea, Republic of)

    2015-12-15

    After the Fukushima nuclear accident in 2011, concerns about radiation by people are increasing rapidly. If people could know how much they will be exposed by radiation, it may help them avoiding it and understand what exactly radiation is. By doing this, we were helping to reduce the anxiety of radiation contamination. In this study, we have researched figures of radioactivity with ‘Captus-3000 thyroid uptake measurement systems’ in well counter detector system. The materials were measured with Briquette, Shiitake, Pollock, Button type battery, Alkaline battery, Topsoil, Asphalt, Gasoline, Milk powder, Pine, Basalt stone, Pencil lead, Wasabi, Coarse salt, Tuna(can) Cigar, Beer, and then we categorized those samples into Land resources, Water resources, Foodstuff and Etc (Beer classified as a water resources has been categorized into Foodstuff). Also, we selected the standard radiation source linear 137Cs to measure the sensitivity of well counter detector. After that, we took cpm(counter per minute) for the well counter detector of thyroid uptake system’s sensitivity. Then we compared the results of each material’s cpm and converted those results to Bq/kg unit. There were a little limitation with the measurement equipment because it has less sensitivity than other professional equipment like ‘High purity germanium radiation detector’. Moreover, We didn’t have many choices to decide the materials. As a result, there are macroscopic differences among the rates of material’s spectrum. Therefore, it had meaningful results that showed how much each material had emitted radiation. To compare the material’s cpm with BKG, we’ve compounded their spectrums. By doing that, we were able to detect some differences among the spectrums at specific peak section. Lastly, Button type battery, Alkaline Battery, Briquette, Asphalt and Topsoil showed high value. There were classified emitting high radiation Group A and emitted lower radiation Group B. The Group A

  8. Variable filtered photographic film as a radiation detector for environmental radiation monitoring

    Science.gov (United States)

    Majid, Zafri Azran Abdul; Junet, Laila Kalidah; Hazali, Norazlanshah; Abdullah, Abdul Adam; Hanafiah, Megat Ahmad Kamal Megat

    2013-05-01

    Environmental radiation is an ionising radiation that present in the natural environment which mostly originates from cosmic rays and radionuclide agents in the environment. This may lead the population to be exposed to the radiation. Therefore, the environmental radiation needs to be observed cautiously to minimize the impact of radiation. However, there is no specific or proper monitoring device that provides an outdoor environmental radiation monitoring. Hence, a new outdoor environmental radiation monitoring device was developed. A photographic film has been chosen as a dosimeter. The purpose of this study was to prove the covered photographic film attached with variable filter can be used to develop environmental radiation monitoring device to detect the ionising radiation. The filter used was variable thickness of plastic, aluminium (Al) and lead (Pb). The result from the study showed that the mean optical density (OD) values for medium speed film are in the range 0.41 to 0.73, and for fast speed film the OD values are in the range 0.51 to 1.35. The OD values decreased when the filter was attached. This has proven that the photographic film can be used to detect radiation and fast speed film was more sensitive compared to medium speed film.

  9. Signal and noise of diamond pixel detectors at high radiation fluences

    Science.gov (United States)

    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 λe/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.

  10. Radiation-hard ASICs for optical data transmission in the ATLAS pixel detector

    CERN Document Server

    Kass, R; Gan, K K; Johnson, M; Kagan, H; Rush, C J; Rahimi, A; Smith, S; Ter-Antonian, R; Zoeller, M M; Ciliox, A; Holder, M; Nderitu, S; Ziolkowski, M

    2003-01-01

    We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode for 80 Mbit/s data transmission from the detector, and a Bi-Phase Mark decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode. We have successfully implemented both ASICs in 0.25 um CMOS technology using enclosed layout transistors and guard rings for increased radiation hardness. We present results from prototype circuits and from irradiation studies with 24 GeV protons up to 57 Mrad (1.9 x 10e15 p/cm2).

  11. Radiation-hard ASICs for optical data transmission in the ATLAS pixel detector

    CERN Document Server

    Gan, K K; Johnson, M; Kagan, H; Kass, R; Rush, C; Smith, S; Ter-Antonian, R; Zoeller, M M; Ciliox, A; Holder, M; Ziolkowski, M

    2005-01-01

    We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode for 80 Mbit/s data transmission from the detector, and a Bi-Phase Mark decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode. We have successfully implemented both ASICs in 0.25 mm CMOS technology using enclosed layout transistors and guard rings for increased radiation hardness. We present results from circuits of final design and from irradiation studies with 24 GeV protons up to 62 Mrad (2.3 x 10^15 p/cm^2).

  12. Radiation-Hard ASICs for Optical Data Transmission in the ATLAS Pixel Detector

    CERN Document Server

    Gan, K K; Johnson, M; Kagan, H; Kass, R; Rush, C; Smith, S; Ter-Antonian, R; Zöller, M; Ciliox, A; Holderb, M; Ziolkowski, M

    2006-01-01

    We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the LHC at CERN: a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode for 80 Mbit/s data transmission from the detector, and a Bi-Phase Mark decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode. We have successfully implemented both ASICs in 0.25 mm CMOS technology using enclosed layout transistors and guard rings for increased radiation hardness. We present results from circuits of final design and from irradiation studies with 24 GeV protons up to 80 Mrad (2.6 x 10^15 p/cm^2).

  13. Ion beam induced charge and cathodoluminescence imaging of response uniformity of CVD diamond radiation detectors

    CERN Document Server

    Sellin, P J; Galbiati, A; Maghrabi, M; Townsend, P D

    2002-01-01

    The uniformity of response of CVD diamond radiation detectors produced from high quality diamond film, with crystallite dimensions of >100 mu m, has been studied using ion beam induced charge imaging. A micron-resolution scanning alpha particle beam was used to produce maps of pulse height response across the device. The detectors were fabricated with a single-sided coplanar electrode geometry to maximise their sensitivity to the surface region of the diamond film where the diamond crystallites are highly ordered. High resolution ion beam induced charge images of single crystallites were acquired that demonstrate variations in intra-crystallite charge transport and the termination of charge transport at the crystallite boundaries. Cathodoluminescence imaging of the same crystallites shows an inverse correlation between the density of radiative centres and regions of good charge transport.

  14. Comparison of Direct Normal Irradiance Derived from Silicon and Thermopile Global Hemispherical Radiation Detectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Development and Studies of Novel Microfabricated Radiation Hard Scintillation Detectors With High Spatial Resolution

    CERN Document Server

    Mapelli, A; Haguenauer, M; Jiguet, S; Renaud, P; Vico Triviño, N

    2011-01-01

    A new type of scintillation detector is being developed with standard microfabrication techniques. It consists of a dense array of scintillating waveguides obtained by coupling microfluidic channels filled with a liquid scintillator to photodetectors. Easy manipulation of liquid scintillators inside microfluidic devices allow their flushing, renewal, and exchange making the active medium intrinsically radiation hard. Prototype detectors have been fabricated by photostructuration of a radiation hard epoxy resin (SU-8) deposited on silicon wafers and coupled to a multi-anode photomultiplier tube (MAPMT) to read-out the scintillation light. They have been characterized by exciting the liquid scintillator in the 200 micrometers thick microchannels with electrons from a 90Sr yielding approximately 1 photoelectron per impinging Minimum Ionizing Particle (MIP). These promising results demonstrate the concept of microfluidic scintillating detection and are very encouraging for future developments.

  16. Software development for studies of diffuse scattering using CCD-detectors and synchrotron radiation sources

    CERN Document Server

    Paulmann, C; Bismayer, U

    2001-01-01

    A graphical-user-interface based software system was developed to cover advanced data processing requirements which arise from studies of diffuse scattering in disordered minerals using synchrotron radiation sources and CCD-detectors. The software includes interfaces to standard applications, procedures for numerical processing of large data sets, corrections for sample external scattering and detector-specific distortions, different scaling options to correct the data set against the varying primary beam intensity as well as procedures to reconstruct arbitrary slices in reciprocal space on a regular grid. The software system was successfully applied in studies of diffuse scattering in disordered REE-doped germanates, phase-transition studies of synthetic titanite and studies of the thermal recrystallization behaviour of radiation-damaged (metamict) minerals.

  17. Simulation of active-edge pixelated CdTe radiation detectors

    Science.gov (United States)

    Duarte, D. D.; Lipp, J. D.; Schneider, A.; Seller, P.; Veale, M. C.; Wilson, M. D.; Baker, M. A.; Sellin, P. J.

    2016-01-01

    The edge surfaces of single crystal CdTe play an important role in the electronic properties and performance of this material as an X-ray and γ-ray radiation detector. Edge effects have previously been reported to reduce the spectroscopic performance of the edge pixels in pixelated CdTe radiation detectors without guard bands. A novel Technology Computer Aided Design (TCAD) model based on experimental data has been developed to investigate these effects. The results presented in this paper show how localized low resistivity surfaces modify the internal electric field of CdTe creating potential wells. These result in a reduction of charge collection efficiency of the edge pixels, which compares well with experimental data.

  18. The SNAP 27 gamma radiation spectrum obtained with a Ge/Li/ detector

    Science.gov (United States)

    Taherzadeh, M.

    1976-01-01

    The pulse height distribution, obtained experimentally using a Ge(Li) detector, was employed to determine the photon emission rate characteristic of a PuO2 fuel source known as the SNAP 27 heat source. The selfshielding parameters of the photon emitter, the efficiency of the detector and the geometry of the experiment were utilized to determine the unscattered photon emission rate of the source and the unscattered flux spectrum at a certain specified distance from the source. For the scattered part of the flux spectrum a Monte Carlo technique was employed so that the total flux spectrum could be determined at any point in the radiation field. As a result of this work, a technique was developed to obtain the unfolded radiation spectrum of the SNAP 27 heat source.

  19. Radiation Exposure in the NICU: Computed Radiography versus Digital Detector Radiography.

    Science.gov (United States)

    Oberle, Renee

    2015-01-01

    Medical radiation exposure to pediatric patients has gained national attention in the last few years. New guidelines encourage technologists, managers, radiologists, and equipment manufacturers to tailor imaging to smaller sized patients. With the advent of computed radiography, patient radiation doses have doubled. This literature review addresses how cumulative doses received by highly radiosensitive infants in neonatal intensive care units correspond to similar doses received by infants that later developed radiation induced cancers. While technologist expertise is important for dose management with any receptor technology, converting to digital flat panel detectors can reduce dose to these areas by > 50%, and minimize risks for radiation induced cancers that often do not present until several decades after exposure. PMID:26710555

  20. Radiation hardness of optoelectronic components for the optical readout of the ATLAS inner detector

    Science.gov (United States)

    Hou, S.; Ishii, K.; Itoh, M.; Sakemi, Y.; Su, D. S.; Su, T. T.; Teng, P. K.; Yoshida, H. P.

    2011-04-01

    Optical links are used for data transmission of the ATLAS inner detector in a radiation hazard environment at the Large Hadron Collider (LHC). The radiation tolerance is studied for the opto-electronics of GaAs VCSEL and epitaxial Si PIN with 30 and 70 MeV protons at CYRIC. High speed Si and GaAs PIN photo-diodes are also investigated for upgrade to super-LHC. The annealing of GaAs VCSEL by charge injection is characterized. The GaAs devices show approximately linear degradations to fluence. The dependence on proton energy is compared to the Non-Ionizing Energy Loss calculations.

  1. Study of Radiation Damage of Silicon Drift Detectors Induced by Fast Neutrons

    CERN Document Server

    Kugler, A; CERN. Geneva; Hanzal, V

    1995-01-01

    We report results of radiation hardness tests of linear Silicon Drift Detectors (SDDs). Non-biased SDDs wre irradiated using flux of fast neutrons with fluency up to 3.5 x 1013 neutrons/cm2. Neutrons were generated due to the stopping of 20 MeV deuteron beam in thick Be target. We have found that electron drift is still possible. However substantional increase in the leakage current of SDDs was observed. Hence, radiation damage will result in corresponding increase of heat generation, which has to be taken into account designing the cooling system of ALICE ITS.

  2. Manufacturing of different gel detectors and their calibration for spatial radiation dose measurements

    International Nuclear Information System (INIS)

    Three types of gel dosemeter have been made and their most important properties for radiation dosimetry were studied. The comparison between the three categories helps to widen knowledge in each of these detectors and to establish a method for the preparation as well as testing of this radiation sensitive materials. Experiments show the technical application possibility for using these gel detectors to measure the spatial radiation dose distribution in the range of doses given for cancer treatment. The experimental results give some important characteristic for the three gel dosemeter used in comparison to that of the traditional dosimetry systems. It also shows the simplicity of manufacturing the dosemeter from low cost materials and its radiation response to ionizing. The relationships between the dosemeter response and the dose rate as well as the radiation energy were also investigated. Important subjects that have been also taken into consideration are the effects of ambient conditions and storage likelihood of the studied materials. Recommendation was made for the use of these materials in practical applications and for handling as well as their long term storage possibility. (author)

  3. Simulation of Portable Gamma Radiation Detectors for Virtual Reality based Training applications.

    OpenAIRE

    MOLTÓ CARACENA, TEÓFILO

    2016-01-01

    [EN] This thesis focuses on the development of a simulator of a gamma radiation portable detector. The aim is to determine the feasibility of such a software tool in a virtual reality (VR) based application, with the purpose of using it in training tasks in the framework of nuclear safeguards and security activities. The work starts with the definition of the series of technical requirements which are necessary to achieve a working prototype of an application of the kind aforementioned. ...

  4. Experimental results on radiation induced bulk damage effects in float-zone and epitaxial silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dezillie, B. [European Organization for Nuclear Research, Geneva (Switzerland); Lemeilleur, F. [European Organization for Nuclear Research, Geneva (Switzerland); Glaser, M. [European Organization for Nuclear Research, Geneva (Switzerland); Casse, G.-L. [European Organization for Nuclear Research, Geneva (Switzerland); Leroy, C. [Montreal Univ., PQ (Canada)

    1997-02-11

    A comparative study of the radiation hardness of silicon pad detectors, manufactured from float-zone and epitaxial n-type monocrystals and irradiated with protons and neutrons up to fluence of 3.5 x 10{sup 14} cm{sup -2} is presented. The results are compared in terms of their reverse current, depletion voltage, and charge collection as a function of fluence during irradiation and as a function of time after irradiation. (orig.).

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

    Directory of Open Access Journals (Sweden)

    Zharkov I.P.

    2015-09-01

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

  6. Development of (Cd,Zn)Te X-ray and gamma ray radiation detectors for medical and security applications

    International Nuclear Information System (INIS)

    Full text: There is a growing need for large area X-and Gamma radiation detectors for penetrating radiations in various fields of application e.g. astronomy, detectors for nuclear medicine, biosensor materials, security, non-proliferation of hazardous materials, and environmental applications etc. Direct X-rays conversion into electric charges in a semiconductor is envisaged with better spectroscopic characteristics to improve contrast and quantitative measurements compared to indirect detection using scintillators. The family of II-VI semiconductor materials combine a range of excellent properties such as their high sensitivity due to the high mobility-lifetime products, their high energy resolution as a consequence of the electron-hole pair formation energy, their reasonable maturity in terms of microelectronic technologies required for commercial detector fabrication, wide range of stopping power and band-gaps available. In particular, CdTe and CdxZn1-xTe (CZT) with Zn=0.1 offer a favorable combination of physical and chemical properties that makes it attractive as a room temperature X-ray detector material of choice for many applications involving photon energies up to several hundreds of keV. From the scientific experience accumulated in the past years, the detector properties are strongly dependent on a series of parameters which must be strictly controlled during crystal growth, such as the homogeneity, stoichiometry and the related intrinsic defects which appear during the material growth, a high mobility-lifetime for electron and holes is mandatory etc. Production of detector-grade CdTe and CdZnTe on industrial scale is still a challenge and optimal growth methods and growth conditions have been under intensive investigation. Progress in crystal growth and characterization achieved in a project of Institute partnership between Charles University in Prague and University of Freiburg, Germany which was sponsored by Alexander von Humboldt Foundation, will be

  7. The ALICE Transition Radiation Detector: status and perspectives for Run II

    CERN Document Server

    Klein, Jochen

    2016-01-01

    The ALICE Transition Radiation Detector contributes to the tracking, particle identification, and triggering capabilities of the experiment. It is composed of six layers of multi-wire proportional chambers, each of which is preceded by a radiator and a Xe/CO$_2$-filled drift volume. The signal is sampled in timebins of 100~ns over the drift length which allows for the reconstruction of chamber-wise track segments, both online and offline. The particle identification is based on the specific energy loss of charged particles and additional transition radiation photons, the latter being a signature for electrons. The detector is segmented into 18 sectors, of which 13 were installed in Run I. The TRD was included in data taking since the LHC start-up and was successfully used for electron identification and triggering. During the Long Shutdown 1, the detector was completed and now covers the full azimuthal acceptance. Furthermore, the readout and trigger components were upgraded. When data taking was started for ...

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

    CERN Document Server

    Fretwurst, E; Al-Ajili, A 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; Bölla, G; Bondarenko, G B; 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 G; Chren, D; Cindro, V; Collins, P; Coluccia, R; Contarato, D; Coutinho, J; Creanza, D; Cunningham, L; Dalla Betta, G F; Dawson, I; de Boer, Wim; 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; García, C; García-Navarro, J E; Gaubas, E; Genest, M H; Gill, K A; Giolo, K; Glaser, M; Gössling, 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; Honniger, F; Horazdovsky, T; Horisberger, R P; Horn, M; Houdayer, A; Hourahine, B; Hughes, G; Ilyashenko, Yu S; 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 P; Kierstead, J A; Klaiber Lodewigs, J M; 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 M; Lastovetsky, V F; Latino, G; Lazanu, I; Lazanu, S; Lebedev, A; Lebel, C; Leinonen, K; Leroy, C; Li, Z; Lindström, G; Linhart, V; Litovchenko, P G; Litovchenko, A P; Lo Giudice, A; Lozano, M; Luczynski, Z; Luukka, Panja; Macchiolo, A; Makarenko, L F; Mandic, I; Manfredotti, C; Manna, N; Martí i García, S; Marunko, S; Mathieson, K; Melone, J; Menichelli, D; Messineo, A; Metcalfe, J; Miglio, S; Mikuz, M; Miyamoto, J; Moll, M; Monakhov, E; Moscatelli, F; Naoumov, D; Nossarzhevska, E; Nysten, J; Olivero, P; O'Shea, 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; Populea, J; Pospísil, S; Pozza, A; Radicci, V; Rafí, J M; Rando, R; Röder, 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; Seidela, S; Seiden, A; Sellberg, G; Sellin, P J; Sentenac, D; Shipsey, I; Sícho, 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

    2005-01-01

    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 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. Furthe...

  9. Radiation Hard Hybrid Pixel Detectors, and a bbbar Cross Section Measurement at the CMS Experiment

    CERN Document Server

    Sibille, Jennifer Ann; Rohe, Tilman Volker

    2013-01-01

    Measurements of heavy flavor quark production at hadron colliders provide agood test of the perturbative quantum chromodynamics (pQCD) theory. Itis also essential to have a good understanding of the heavy quark productionin the search for new physics. Heavy quarks contribute to backgrounds andsignals in measurements of higher mass objects, such as the Higgs boson. Akey component to each of these measurements is good vertex resolution. Inorder to ensure reliable operation of the pixel detector, as well as confidencein the results of analyses utilizing it, it is important to study the effects ofthe radiation on the detector.In the first part of this dissertation, the design of the CMS silicon pixeldetector is described. Emphasis is placed on the effects of the high radiation environment on the detector operation. Measurements of the chargecollection efficiency, interpixel capacitance, and other properties of the pixelsensors as a function of the radiation damage are presented.In the second part, a measurem...

  10. Reconstruction of charged particle fluxes detected by the Radiation Assessment Detector onboard of MSL

    Science.gov (United States)

    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.

  11. XNAP: a hybrid pixel detector with nanosecond resolution for time resolved synchrotron radiation studies

    Science.gov (United States)

    Fajardo, P.; Baron, A. Q. R.; Dautet, H.; Davies, M.; Fischer, P.; Göttlicher, P.; Graafsma, H.; Hervé, C.; Rüffer, R.; Thil, C.

    2013-03-01

    The XNAP collaboration is constructing a hybrid pixel X-ray detector based on a monolithic silicon avalanche photodiode (APD) sensor array aiming at applications in synchrotron radiation facilities. The 2D detector is capable of identifying which individual electron bunch produces each detected X-ray photon, even when the storage ring operates in multibunch filling modes. This instrument is intended to be used in X-ray Photon Correlation Spectroscopy and Nuclear Resonance experiments and serve as a demonstrator for various kind of time resolved diffraction and scattering applications as well as a very high count rate device. The detector is a 1 kilopixel device with 280 μm pitch that implements both counting mode up to MHz frame rates and event-by-event readout with sub-nanosecond time resolution. The paper describes the detector design and some results obtained with small 4×4 pixel prototypes that have been built and measured to make and validate the most critical choices for the final detector.

  12. Frontal IBICC study of the induced proton radiation damage in CdTe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Pastuovic, Zeljko E-mail: pastu@rudjer.irb.hr; Jaksic, Milko

    2001-07-01

    Within a continuous international effort in developing the non-cryogenic semiconductor detectors for gamma ray spectroscopy, various wide gap materials were considered. With a best performance achieved, CdTe- and CdZnTe-based detectors become today widely accepted and commercially available. In addition to possible future use of such detectors for particle-induced gamma-ray emission (PIGE), nuclear microprobes are in recent years applied more as their characterisation tool using the ion beam-induced charge collection (IBICC) technique. Several CdTe detectors of 2x2x1 mm{sup 3} size were used in this study. On the basis of frontal IBICC measurements of the charge collection efficiency (CCE) distribution, the spectroscopy performance of detectors were measured. Further degradation of charge collection efficiency and the downward trend in peak position were studied by on-line irradiation of CdTe samples with 3 MeV protons up to 10{sup 10} p/cm{sup 2} radiation dose.

  13. Frontal IBICC study of the induced proton radiation damage in CdTe detectors

    Science.gov (United States)

    Pastuović, Željko; Jakšić, Milko

    2001-07-01

    Within a continuous international effort in developing the non-cryogenic semiconductor detectors for gamma ray spectroscopy, various wide gap materials were considered. With a best performance achieved, CdTe- and CdZnTe-based detectors become today widely accepted and commercially available. In addition to possible future use of such detectors for particle-induced gamma-ray emission (PIGE), nuclear microprobes are in recent years applied more as their characterisation tool using the ion beam-induced charge collection (IBICC) technique. Several CdTe detectors of 2×2×1 mm3 size were used in this study. On the basis of frontal IBICC measurements of the charge collection efficiency (CCE) distribution, the spectroscopy performance of detectors were measured. Further degradation of charge collection efficiency and the downward trend in peak position were studied by on-line irradiation of CdTe samples with 3 MeV protons up to 10 10 p/cm2 radiation dose.

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

    CERN Document Server

    Funaki, M; Satoh, K; Ohno, R

    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 B was also effective to limit the generation of twins having different directions. Single-crystal (1 1 1) wafers, larger than 30x30 mm sup 2 were successfully obtained from a grown crystal of 50 mm diameter. Pt/CdTe/Pt detectors of dimensions 4x4x2 mm sup 3 , fabricated from the whole crystal ingot, showed an energy resolution (FWHM of 122 keV peak from a sup 5 sup 7 Co source) between 6% and 8%. Similarly, Pt/CdTe/In detectors of dimensions 2x2x0.5 mm sup 3 showed a resolution better than 3%. These characteristics encourage the practical applications of various types of CdTe detectors.

  15. Radiation tests of ATLAS full-sized n-in-n prototype detectors

    Energy Technology Data Exchange (ETDEWEB)

    Allport, P.P.; Booth, P.S.L.; Green, C.; Greenall, A.; Hanlon, M.; Jackson, J.N.; Jones, T.J.; Garcia, S.M.I.; Orme, E.; Richardson, J.D.; Smith, N.A.; Turner, P.R.; Wormald, M.P. [Oliver Lodge Laboratory, Department of Physics, The University of Liverpool, P.O. Box 147, Liverpool L69 EBX (United Kingdom); Apsimon, R.J.; Bizzell, J.; Tyndel, M. [Rutherford Appleton Laboratory, Didcot EBX (United Kingdom); Becker, C.; Thuene, R.; Wunstorf, R.; Wuestenfeld, J. [Experimentelle Physik, Universitaet Dortmund EBX (Germany); Bonino, R.; Perrin, E.; Clark, A.G.; Couyoumtzelis, C.; Kowalewski, R.; Macina, D.; Vuaridel, B. [Section de Physique, Universite de Geneve EBX (Switzerland); Boulter, B.; Riedler, P.; Roe, S. [European Laboratory for Particle Physics (CERN) Geneva (Switzerland); Carter, A.A.; Newman-Coburn, D. [Department of Physics, Queen Mary and Westfield College, London (United Kingdom); Carter, J.R.; Goodrick, M.J.; Hill, J.C.; Munday, D.J.; Robinson, D.; Wyllie, K.H. [Cavendish Laboratory, The University of Cambridge EBX (United Kingdom); O' Shea, V. [Department of Physics and Astronomy, The University of Glasgow EBX (United Kingdom)

    1998-11-21

    ATLAS Technical Proposal, CERN/LHCC/94-43 has adopted n-side read out All rights reserved.)s. (Copyrbaseline technology for the silicon microstrips due to the anticipated radiation tolerance of such a design ATLAS Inner Detector Technical Design Report, CERN/LHCC/97-17. This results from the reasonable efficiencies anticipated for charge collection, even when the detectors are run well below the final depletion voltage.Full-sized prototypes 64x63.6 mm{sup 2} detectors have been produced with a range of manufacturers to a common specification and shown to work well in test-beam with ATLAS electronics. A selection of detectors was also scanned in the CERN PS beam for runs of two weeks giving an integrated dose over the full surface of 2x10{sup 14} p/cm{sup 2}. This dose corresponds to the highest charged hadron fluence expected in 10 yr of operation in ATLAS.Results are presented on these detectors both from parametric measurements and from studies using analogue LHC speed electronics. The detectors are shown to remain fully operational after these doses and to yield high signal/noise for read-out of 12 cm strip length. The performance partially depleted is also shown to match expectations and operation at down to half the final depletion voltage gives adequate efficiencies. Uncertainties in the anticipated dose and damage effects argue strongly for this additional robustness in detectors which must operate with very limited access in the hostile environment of the LHC for 10 yr. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  16. Implementation of radiation image detector based on lutetium and gadolinium phosphors

    Science.gov (United States)

    Lee, Y.; Shin, J.; Oh, K.; Noh, S.; Kim, D.; Kim, J.; Hong, J.; Park, S.; Kim, J.; Nam, S.

    2013-03-01

    The clinical use of radiation image detectors is influenced by the degree to which patients are exposed to radiation. Phosphors are being used as the radiation receptor materials in a number of radiation imaging systems for the detection of radiation. Rare earth phosphors such as those of Gd, Y, Lu, and La are attracting attention in particular as they exhibit improved properties. However, there has not been any research on the conditions for the synthesis of these phosphors, including the optimal concentrations in which the sensitizer should be added to them. Therefore, in this study, the optimal conditions for the phosphor synthesis were determined by analyzing the characteristics of the phosphors fabricated using various sensitizer concentrations. The deposition method used to form films of the synthesized phosphors was screen printing. This technique is suitable for large-area deposition and allowed for imaging to be performed in conjunction with a complementary metal-oxide semiconductor (CMOS) image detector. The phosphors synthesized were Gd2O3:Eu and Lu2O3:Eu, and the sensitizer used was citric acid, which was added in varying concentrations (0.00-0.05 g) to the phosphors during synthesis. Films of the phosphors 5 × 5 cm in size, which was the size of the active area of the CMOS image sensor, and 100-250 μm in thickness were formed. The structural characteristics of the phosphors were determined through X-ray diffraction analyses and scanning electron microscopy, and the optical characteristics through photoluminescence (PL) measurements. A CMOS-based X-ray detector was manufactured by attaching the phosphor films to the CMOS image sensor and evaluating the modulation transfer functions of the images obtained. The results showed that of all the phosphor samples synthesized, the Gd2O3:Eu and Lu2O3:Eu samples synthesized using 0.02 g of citric acid exhibited the best luminescence characteristics.

  17. Uncooled Radiation Hard Large Area SiC X-ray and EUV Detectors and 2D Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project seeks to design, fabricate, characterize and commercialize large area, uncooled and radiative hard 4H-SiC EUV ? soft X-ray detectors capable of ultra...

  18. Radiation hardness of silicon detectors manufactured on epitaxial material and FZ bulk enriched with oxygen, carbon, tin and platinum

    CERN Document Server

    Ruzin, A; Glaser, M; Lemeilleur, F; Talamonti, R; Watts, S; Zanet, A

    1999-01-01

    Recent results on the radiation hardness of silicon detectors fabricated on epitaxial and float zone bulk silicon enriched by various impurities, such as carbon, oxygen, tin and platinum are reported. A new methodology of measurements of electrical properties of the devices has been utilized in the experiment. It has been shown that in the case of irradiation by protons, oxygen enriched silicon has better radiation hardness than standard float zone silicon. The carbon enriched silicon detectors, on the other hand, exhibited significantly inferior radiation hardness compared to standard detectors. This study shows for the first time, a violation of the widely used normalization technique of the various particle irradiations by NIEL coefficients. The study has been carried out in the framework of the RD48 (ROSE) collaboration, which studies the radiation hardening of silicon detectors. (5 refs).

  19. Radiation hardness of silicon detectors manufactured on epitaxial material and FZ bulk enriched with oxygen, carbon, tin and platinum

    International Nuclear Information System (INIS)

    Recent results on the radiation hardness of silicon detectors fabricated on epitaxial and float zone bulk silicon enriched by various impurities, such as carbon, oxygen, tin and platinum are reported. A new methodology of measurements of electrical properties of the devices has been utilized in the experiment. It has been shown that in the case of irradiation by protons, oxygen enriched silicon has better radiation hardness than standard float zone silicon. The carbon enriched silicon detectors, on the other hand, exhibited significantly inferior radiation hardness compared to standard detectors. This study shows for the first time, a violation of the widely used normalization technique of the various particle irradiations by NIEL coefficients. The study has been carried out in the framework of the RD48 (ROSE) collaboration, which studies the radiation hardening of silicon detectors

  20. Lessons learned from the Radiation measurements of the Mars Science Lab Radiation Assessment Detector (MSL-RAD)

    Science.gov (United States)

    Reitz, Guenther; Ottolenghi, Andrea

    2016-07-01

    The Radiation Assessment Detector (RAD) was designed to characterize the radiation environment on the Mars surface and to contribute to an improved assessment of radiation risk for a future human mission to Mars. The flight was chosen to cover a period of solar maximum activity to allow besides the measurement of the galactic cosmic rays an intense study of exposures by solar particle events. The Mars Science Laboratory spacecraft (MSL), containing the Curiosity rover, in which RAD was integrated, was launched to Mars on November 26, 2011. Although not part of the mission planning, RAD was operated already during the 253 day and 560 million km cruise to Mars and made the first time detailed measurements of a radiation environment comparable to that inside a future spacecraft carrying humans to Mars and in other deep space missions. Exactly 100 years after the discovery of cosmic rays on August 7, 1912 RAD makes the first observation of the radiation environment on the surface of another planet and is still gathering data until today. Meanwhile the maximum activity of the current solar cycle has been passed and the solar activity is decreasing. Unfortunately the present solar cycle was an unexpected weak cycle. As a matter of fact only very small solar particle events could be observed during the still ongoing RAD measurements. The paper highlights the achievements of RAD by presenting selected data measured during the cruise and on the Mars surface and describes its impact on predictive models for health risks of astronauts during space missions.

  1. Radiation-chemical oxidation of adamantylideneadamantane with dioxetane formation

    International Nuclear Information System (INIS)

    Liquid-phase radiation-chemical oxidation of adamantylideneadamantane with 1,2-dioxetane formation is studied. Gamma-irradiation is carried out with the doses up to 17.2 kGy, the dose rate being 1.2 Gy/s. It is shown that the main chance of radiation-chemical oxidation of this alkene is radical expoxidation. One of the sources of radical generation in acetone is the process of oxygen quenching the triplet acetone. In the presence of intermediaries passing excitation to dissolved oxygene in solvents with high yield of excited states generation 1O2 is produced, and alkene is oxidized to dioxetane. Therewith, the epoxide yield is decreased, the dioxetane and epoxide yield ratio is defined by competition between reactions of O2 and intermediaries leading to 1O2 or radical products

  2. Small Teleoperated Robot for Nuclear Radiation and Chemical Leak Detection

    Directory of Open Access Journals (Sweden)

    Kui Qian

    2012-09-01

    Full Text Available In order to meet the actual requirements of nuclear radiation and chemical leak detection, and emergency response, a new small teleoperated robot for nuclear radiation and chemical detection is proposed. A small‐size robot is manufactured according to technical requirements and the overall structure and control system is described. Meanwhile, based on the principles of human‐robot interaction, a user‐friendly human‐robot interaction interface is designed to provide a good telepresence for the operator, helping the operator to perceive and judge the robot’s situation to better assist in making the right decisions and in giving timely operation instructions. The experiment results show the robot system operates reliably and meets the technical requirements.

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

    Science.gov (United States)

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

    2014-11-01

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

  4. Harmonization of risk management approaches: radiation and chemical exposures

    International Nuclear Information System (INIS)

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  5. Harmonization of risk management approaches: radiation and chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, P. [Bhabha Atomic Research Centre, Radiation Safety Systems Div., Mumbai (India)

    2006-07-01

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  6. Hilbert Spectral Analysis of THz Radiation Sources by High-Tc Josephson Detectors

    Science.gov (United States)

    Divin, Yuriy; Lyatti, Matvey; Poppe, Ulrich

    A Hilbert spectrum analyzer was developed and characterized with monochromatic radiation sources at the frequency range from 30 GHz to 1 THz. The analyzer was based on a high-Tc frequency-selective Josephson detector and cooled to temperatures of 60-80K by a Stirling cryocooler. The instrumental function of the spectrum analyzer was shown to be of Lorentz type and within accuracy up to 0.1% without any harmonic and subharmonic contributions. Spectral characterization of THz sources, based on frequency multiplication of input microwave radiation by Schottky diodes, was demonstrated for input frequencies from 10 to 20 GHz with a total scanning time as low as 50 ms per scan. The developed Hilbert spectrum analyzer might be considered as a compact and high-speed substitute of conventional Fourier spectrometers, which are used for characterization of THz radiation sources in combination with liquid-helium-cooled silicon bolometers.

  7. Nuclear reactor pulse tracing using a CdZnTe electro-optic radiation detector

    Science.gov (United States)

    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.

  8. The iQID camera: An ionizing-radiation quantum imaging detector

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Brian W., E-mail: brian.miller@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); College of Optical Sciences, The University of Arizona, Tucson, AZ 85719 (United States); Gregory, Stephanie J.; Fuller, Erin S. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Barrett, Harrison H.; Bradford Barber, H.; Furenlid, Lars R. [Center for Gamma-Ray Imaging, The University of Arizona, Tucson, AZ 85719 (United States); College of Optical Sciences, The University of Arizona, Tucson, AZ 85719 (United States)

    2014-12-11

    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.

  9. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    International Nuclear Information System (INIS)

    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 ∼400 MHz and the noise charge ∼1000 electrons at a 1 μsec 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 ∼0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB

  10. Radiation tolerance of the readout chip for the Phase I upgrade of the CMS pixel detector

    International Nuclear Information System (INIS)

    For the Phase I upgrade of the CMS pixel detector a new digital readout chip (ROC) has been developed. An important part of the design verification are irradiation studies to ensure sufficient radiation tolerance. The paper summarizes results of the irradiation studies on the final ROC design for the detector layers 2 – 4. Samples have been irradiated with 23 MeV protons to accumulate the expected lifetime dose of 0.5 MGy and up to 1.1 MGy to project the performance of the ROC for layer 1 of the detector. It could be shown that the design is sufficiently radiation tolerant and that all performance parameters stay within their specifications. Additionally, very high doses of up to 4.2 MGy have been tested to explore the limits of the current chip design on 250 nm CMOS technology. The study confirmed that samples irradiated up to the highest dose could be successfully operated with test pulses

  11. Radiation-hard ASICs for optical data transmission in the ATLAS pixel detector

    CERN Document Server

    Ziolkowski, M; Buchholz, P; Ciliox, A; Gan, K K; Holder, M; Johnson, M; Kagan, H; Kass, R; Nderitu, S; Rahimi, A; Rush, C J; Smith, S; Ter-Antonian, R; Zoeller, M M

    2004-01-01

    We have developed two radiation-hard ASICs for optical data transmission in the ATLAS pixel detector at the CERN Large Hadron Collider (LHC). The first circuit is a driver chip for a Vertical Cavity Surface Emitting Laser (VCSEL) diode to be used for 80 Mbit/s data transmission from the detector. The second circuit is a Bi-Phase Mark, decoder chip to recover the control data and 40 MHz clock received optically by a PIN diode on the detector side. During ten years of operation at the LHC, the ATLAS optical link circuitry will be exposed to a maximum total fluence of 10/sup 15/ 1-MeV-equivalent neutrons per cm/sup 2/. We have successfully implemented both ASICs in a commercial 0.25 mu m CMOS technology using standard layout techniques to enhance the radiation tolerance. Both chips are four- channel devices compatible with common cathode PIN and VCSEL arrays. We present results from final prototype circuits and from irradiation studies of both circuits with 24 GeV protons up to a total dose of 57 Mrad. (3 refs).

  12. Analysis of the radiation tolerance of the LHCb silicon vertex detector

    CERN Document Server

    Feick, H

    1998-01-01

    This note analyses the radiation tolerance of the LHC-B silicon vertex detector in the framework of the latest damage models put forward by the ROSE / CERN RD 48 Collaboration. The calculations assume constant temperature and constant flux for a one year beam period of 240 d. It is found that the ultimate failure of the detectors is due to the damage-induced doping changes causing the loss of sensitive volume. Increases in the leakage current and carrier trapping stay at a tolerable level. Given a suitable operating temperature (5 degree C) and initial resistivity, detectors of 150 _m (480 \\Omega cm) and 200 _m (850\\Omega cm) thickness are expected to remain fully depleted with 200 V up to equivalent 1-MeV neutron fluences of 5 \\Theta 1014cm\\Gamma 2and 9 \\Theta 1014cm\\Gamma 2, respectively. Admitting partially depleted operation, the lower benchmarkfigure of 7000 collected electrons is reached at radiation doses as high as 8 \\Theta 1014cm\\Gamma 2 and1 \\Theta 1015cm\\Gamma 2, respectively. A conservative 50 4.0...

  13. Signal and noise of Diamond Pixel Detectors at High Radiation Fluences

    CERN Document Server

    Tsung, Jieh-Wen; Hügging, Fabian; Kagan, Harris; Krüger, Hans; Wermes, Norbert

    2012-01-01

    CVD diamond is an attractive material option for LHC vertex detectors 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 10$^{15}$ n$_{eq}$ 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, 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 chang...

  14. Neutron measurements with Time-Resolved Event-Counting Optical Radiation (TRECOR) detector

    Science.gov (United States)

    Brandis, M.; Vartsky, D.; Dangendorf, V.; Bromberger, B.; Bar, D.; Goldberg, M. B.; Tittelmeier, K.; Friedman, E.; Czasch, A.; Mardor, I.; Mor, I.; Weierganz, M.

    2012-04-01

    Results are presented from the latest experiment with a new neutron/gamma detector, a Time-Resolved, Event-Counting Optical Radiation (TRECOR) detector. It is composed of a scintillating fiber-screen converter, bending mirror, lens and Event-Counting Image Intensifier (ECII), capable of specifying the position and time-of-flight of each event. TRECOR is designated for a multipurpose integrated system that will detect Special Nuclear Materials (SNM) and explosives in cargo. Explosives are detected by Fast-Neutron Resonance Radiography, and SNM by Dual Discrete-Energy gamma-Radiography. Neutrons and gamma-rays are both produced in the 11B(d,n+γ)12C reaction. The two detection modes can be implemented simultaneously in TRECOR, using two adjacent radiation converters that share a common optical readout. In the present experiment the neutron detection mode was studied, using a plastic scintillator converter. The measurements were performed at the PTB cyclotron, using the 9Be(d,n) neutron spectrum obtained from a thick Be-target at Ed ~ 13 MeV\\@. The basic characteristics of this detector were investigated, including the Contrast Transfer Function (CTF), Point Spread Function (PSF) and elemental discrimination capability.

  15. Biological effects of low level exposures to chemicals and radiation

    International Nuclear Information System (INIS)

    In May 1990 a group of scientists representing several federal agencies, the International Society of Regulatory Toxicology and Pharmacology, the private sector, and academia met to develop a strategy to encourage the study of the biological effects of low level exposures (BELLE) to chemical agents and radioactivity. A workshop was held in 1991 with seven invited speakers focusing on the toxicological implications of biological adaptations. The selection of topics and speakers was designed to consider critically the concept of hormesis, not only in a broad, conceptual manner, but also at the molecular and biochemical levels. These presentations offered a complementary perspective on the diverse range of molecular mechanisms that can become activated at low levels of toxicant exposure. In addition to chemical toxicology research, an overview of current research on 'Effects of low-dose radiation on the immune response' was presented as well as 'Cellular adaptation as an important response during chemical carcinogenesis'. The final presentation was devoted to biostatistical considerations when designing studies that address issues associated with the biological responses to low doses of chemicals and radiation, as well as issues in interpretation of the findings from such studies

  16. Investigation of epitaxial silicon layers as a material for radiation hardened silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. CMS Run-2 Instrumentation for beam radiation and luminosity measurement using novel detector technologies

    Science.gov (United States)

    Gomez Espinosa, Alejandro; CMS Collaboration Collaboration

    2016-03-01

    The higher energy and luminosity for Run 2 at the LHC initiated the development of dedicated technologies for beam radiation monitoring and luminosity measurement. A dedicated pixel luminosity detector measures coincidences in several three layer telescopes of silicon pixel detectors to arrive at a luminosity for each colliding LHC bunch pair. The full pixel data is also read out at a lower rate to reconstruct charged particle tracks for monitoring and beam spot determination. The upgraded fast beam conditions monitor measures the particle flux using 24 two pad single crystalline diamond sensors, equipped with a fast front-end ASIC, produced in 130 nm CMOS technology, for excellent time resolution. A new beam-halo monitor exploits Cerenkov light production in fused quartz crystals to provide direction sensitivity and excellent time resolution to separate incoming and outgoing particles. The back-end electronics of the beam monitoring systems include dedicated modules with high bandwidth digitizers developed in both VME and microTCA standards for per bunch beam measurements and gain monitoring. All sub-detectors have been taking data from the first day of LHC operation in April 2015. Detector performance results from the 2015 LHC Run II will be presented.

  18. Gamma-spectrometric module based on HPGe detector for radiation portal monitors

    Directory of Open Access Journals (Sweden)

    Kondratjev Vladimir

    2015-01-01

    Full Text Available The appearance of small-sized and powerful enough electric cryocoolers of various types on the market, has opened the perspective of HPGe detectors application, cooled by such coolers, in radiation portal monitors. The first results of a spectrometric module based on HPGe detector with relative efficiency of 45% cooled by a Stirling-cycle cryocooler, are presented. The spectrometer has provided energy resolutions of less than 0.95 keV and 1.95 keV at energies of 122 keV and 1332 keV, respectively. The deterioration of the energy resolution of HPGe detector cooled by electric cryocooler in comparison to the resolution with liquid nitrogen cooling was about 8% at the energy of 1332 keV. With the use of activated filters to suppress pulses produced by the mechanical vibrations, the energy resolution of the spectrometer was 0.8 keV and 1.8 keV, respectively, however, the detector relative efficiency at the energy of 1332 keV has dropped to 39 %.

  19. Computed neutron response of spherical moderator-detector systems for radiation protection monitoring

    International Nuclear Information System (INIS)

    Neutrons of energies below 500 keV are important from the point of view of radiation protection of personnel working around reactors. However, as no neutron sources are available at lower energies, no measured values of neutron energy response are available between thermal and 0.5 MeV (but for Sb-Be source at 24 keV). The response functions in this range are, therefore, arrived at theoretically. After giving a comprehensive review of the work done in the field of response of moderated neutron detectors, a Monte Carlo method developed for this purpose is described and used to calculate energy response functions of the two spherical moderator-detector systems, namely, one using a central BF3 counter and the other using 6LiI(Eu) scintillator of 0.490 dia crystal. The polythene sphere diameter ranged from 2'' to 12''. The results obtained follow the trend predicted by other calculations and experiments, but are a definite improvement over them, because the most recent data on cross sections and angular distribution are used and the opacity of the detector i.e. the presence and size of the detector within the moderator is taken into account in the present calculations. The reasons for the discrepancies in the present results and those obtained earlier by other methods are discussed. The response of the Leake counter arrived at by the present method agrees very well with experimental calibration. (M.G.B.)

  20. Measurements of High Energy X-Ray Dose Distributions Using Multi-Dimensional Fiber-Optic Radiation Detectors

    Science.gov (United States)

    Jang, Kyoung Won; Cho, Dong Hyun; Shin, Sang Hun; Lee, Bongsoo; Chung, Soon-Cheol; Tack, Gye-Rae; Yi, Jeong Han; Kim, Sin; Cho, Hyosung

    In this study, we have fabricated multi-dimensional fiber-optic radiation detectors with organic scintillators, plastic optical fibers and photo-detectors such as photodiode array and a charge-coupled device. To measure the X-ray dose distributions of the clinical linear accelerator in the tissue-equivalent medium, we have fabricated polymethylmethacrylate phantoms which have one-dimensional and two-dimensional fiber-optic detector arrays inside. The one-dimensional and two-dimensional detector arrays can be used to measure percent depth doses and surface dose distributions of high energy X-ray in the phantom respectively.

  1. Comparison of Martian Surface Radiation Predictions to the Measurements of Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    Science.gov (United States)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan; Koehler, Jan; Martin, Cesar; Reitz, Guenther; Posner, Erik

    2014-01-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, detailed knowledge of particle spectra is an important factor. Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Mars Science Laboratory Radiation Assessment Detector (MSL-RAD) on the Curiosity rover since August 2012, and particle fluxes for a wide range of ion species (up to several hundred MeV/u) and high energy neutrons (8 - 1000 MeV) have been available for the first 200 sols. Although the data obtained on the surface of Mars for 200 sols are limited in the narrow energy spectra, the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code are compared to the data. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used, which includes direct knockout, evaporation and nuclear coalescence. Daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station are implemented into transport calculations for describing the daily column depth of atmosphere. Particles impinging on top of the Martian atmosphere reach the RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD by the rest of the instrument. Calculations of stopping particle spectra are in good agreement with the RAD measurements for the first 200 sols by accounting changing heliospheric conditions and atmospheric pressure. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and thus increase the accuracy of the predictions of future radiation environments on Mars. These contributions lend support to the understanding of radiation health risks to

  2. Comparison of Martian Surface Radiation Predictions to the Measurements of Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    Science.gov (United States)

    Kim, M. H. Y.; Cucinotta, F.; Zeitlin, C. J.; Hassler, D.; Ehresmann, B.; Rafkin, S. C.; Wimmer-Schweingruber, R. F.; Böttcher, S. I.; Boehm, E.; Guo, J.; Kohler, J.; Martin-Garcia, C.; Reitz, G.; Posner, A.

    2014-12-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, detailed knowledge of particle spectra is an important factor. Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Mars Science Laboratory Radiation Assessment Detector (MSL-RAD) on the Curiosity rover since August 2012, and particle fluxes for a wide range of ion species (up to several hundred MeV/u) and high energy neutrons (8 - 1000 MeV) have been available for the first 200 sols. Although the data obtained on the surface of Mars for 200 sols are limited in the narrow energy spectra, the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code are compared to the data. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used, which includes direct knockout, evaporation and nuclear coalescence. Daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station are implemented into transport calculations for describing the daily column depth of atmosphere. Particles impinging on top of the Martian atmosphere reach the RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD by the rest of the instrument. Calculations of stopping particle spectra are in good agreement with the RAD measurements for the first 200 sols by accounting changing heliospheric conditions and atmospheric pressure. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and thus increase the accuracy of the predictions of future radiation environments on Mars. These contributions lend support to the understanding of radiation health risks to

  3. Traceable calibration of a fibre-coupled superconducting nano-wire single photon detector using characterized synchrotron radiation

    Science.gov (United States)

    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.

  4. Local Signal Processing of the ALICE Transition Radiation Detector at LHC (CERN)

    CERN Document Server

    Gutfleisch, Marcus

    2006-01-01

    The transition radiation detector of the heavy ion experiment ALICE at LHC (CERN) integrates parts of the data acquisition and trigger system. Therefore, a multi chip module has been developped which incorporates two microchips. Detector signals are preamplified and shaped (Preamplifier and Shaper Chip, PASA). Thereafter they are converted from analog to digital and are processed (Tracklet Processing Chip, TRAP). This thesis describes the digital signal processing of the TRAP chip. The input signals are filtered digitally. Then, they are analyzed by a preprocessor and four CPUs with respect to segments of tracks. The thesis covers the complete development from hardware design of filter and preprocessor, their calibration, programming of the CPUs, up to first application studies on a prototype system.

  5. Instrumentation for beam radiation and luminosity measurement in the CMS experiment using novel detector technologies

    CERN Document Server

    Guthoff, Moritz

    2016-01-01

    The higher energy and luminosity of the LHC initiated the development of dedicated technologies for radiation monitoring and luminosity measurement. A pixelated luminosity detector counts coincidences in several three layer telescopes of silicon pixel detectors to measure the luminosity for each colliding LHC bunch pair. In addition, charged particle tracking allows to monitor the location of the collision point.The upgraded fast beam conditions monitor measures the particle flux using 24 two pad single crystalline diamond sensors, equipped with a fast front-end ASIC produced in 130 nm CMOS technology. The excellent time resolution is used to separate collision products from machine induced background.A new beam-halo monitor at larger radius exploits Cerenkov light produced by relativistic charged particles in fused quartz crystals to provide direction sensitivity and time resolution to separate incoming and outgoing particles. The back-end electronics of the beam monitoring systems includes dedicated modules...

  6. Energy cross-calibration from the first CREAM flight: transition radiation detector versus calorimeter

    CERN Document Server

    Maestro, P; Allison, P S; Bagliesi, M G; Beatty, J J; Bigongiari, G; Boyle, P J; Brandt, T J; Childers, J T; Conklin, N B; Coutu, S; Duvernois, M A; Ganel, O; Han, J H; Hyun, H J; Jeon, J A; Kim, K C; Lee, J K; Lee, M H; Lutz, L; Marrocchesi, P S; Malinine, A; Minnick, S; Mognet, S I; Nam, S; Nutter, S; Park, H; Park, I H; Park, N H; Seo, E S; Sina, R; Swordy, S; Wakely, S P; Wu, J; Yang, J; Yoon, Y S; Zei, R; Zinn, S Y

    2010-01-01

    The Cosmic Ray Energetics And Mass (CREAM) balloon experiment had two successful flights in 2004/05 and 2005/06. It was designed to perform energy measurements from a few GeV up to 1000 TeV, taking advantage of different detection techniques. The first instrument, CREAM-1, combined a transition radiation detector with a calorimeter to provide independent energy measurements of cosmicraynuclei. Each detector was calibrated with particle beams in a limited range of energies. In order to assess the absolute energy scale of the instrument and to investigate the systematic effects of each technique, a cross-calibration was performed by comparing the two independent energy estimates on selected samples of oxygen and carbon nuclei.

  7. Very Low-Power Consumption Analog Pulse Processing ASIC for Semiconductor Radiation Detectors

    International Nuclear Information System (INIS)

    We describe a very-low power consumption circuit for processing the pulses from a semiconductor radiation detector. The circuit was designed for use with a cadmium zinc telluride (CZT) detector for unattended monitoring of stored nuclear materials. The device is intended to be battery powered and operate at low duty-cycles over a long period of time. This system will provide adequate performance for medium resolution gamma-ray pulse-height spectroscopy applications. The circuit incorporates the functions of a charge sensitive preamplifier, shaping amplifier, and peak sample and hold circuit. An application specific integrated circuit (ASIC) version of the design has been designed, built and tested. With the exception of the input field effect transistor (FET), the circuit is constructed using bipolar components. In this paper the design philosophy and measured performance characteristics of the circuit are described

  8. Fast bolometric response by high T sub c detectors measured with subnanosecond synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Carr, G.L.; Quijada, M.; Tanner, D.B. (Department of Physics, University of Florida, Gainesville, Florida 32611 (USA)); Hirschmugl, C.J.; Williams, G.P. (National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973 (USA)); Etemad, S.; Dutta, B.; DeRosa, F.; Inam, A.; Venkatesan, T. (Bell Communications Research, Red Bank, New Jersey 07701 (USA)); Xi, X. (Department of Physics, Rutgers University, Piscataway, New Jersey 08855 (USA))

    1990-12-17

    We have measured a fast response by thin-film YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} detectors to pulsed, broadband, infrared radiation. Synchrotron light from an electron storage ring was used as the infrared source, providing subnanosecond pulses from far infrared through visible. Pulse responsivities as high as 10{sup 6} V/J and as fast as 4 ns have been observed. For film thicknesses in the range 400--3200 A, the detector response follows the film absorptivity while the speed varies inversely with thickness, suggesting a bolometric mechanism. Calculations based on such a model are in accord with the data. We find no evidence for any nonbolometric components in the response.

  9. High-performance diamond radiation detectors produced by lift-off method

    Science.gov (United States)

    Shimaoka, Takehiro; Kaneko, Junichi H.; Tsubota, Masakatsu; Shimmyo, Hiroaki; Watanabe, Hideyuki; Chayahara, Akiyoshi; Umezawa, Hitoshi; Shikata, Shin-ichi

    2016-03-01

    For stable semiconductor detector operation under harsh environments, an ideal single-crystal diamond without a charge trapping centre is required. For this study, a self-standing single-crystal CVD diamond was fabricated using a lift-off method. The reduction of charge trapping factors such as structural defects, point defects, and nitrogen impurities, was attempted using 0.2% of low-methane concentration growth and using a full metal seal chamber. A high-quality self-standing diamond with strong free-exciton recombination emission was obtained. Charge collection efficiencies were 100.1% for holes and 99.8% for electrons, provided that \\varepsilon{diamond}= 13.1 \\text{eV} and \\varepsilon{Si}=3.62 \\text{eV} . Energy resolutions were 0.38% for both holes and electrons. We produced a high-performance diamond radiation detector using the productive lift-off method.

  10. Very Low-Power Consumption Analog Pulse Processing ASIC for Semiconductor Radiation Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, K.O.; Lund, J.C.; Brunett, B.A.; Laguna, G.R.; Clements, J.W.

    1999-08-23

    We describe a very-low power consumption circuit for processing the pulses from a semiconductor radiation detector. The circuit was designed for use with a cadmium zinc telluride (CZT) detector for unattended monitoring of stored nuclear materials. The device is intended to be battery powered and operate at low duty-cycles over a long period of time. This system will provide adequate performance for medium resolution gamma-ray pulse-height spectroscopy applications. The circuit incorporates the functions of a charge sensitive preamplifier, shaping amplifier, and peak sample and hold circuit. An application specific integrated circuit (ASIC) version of the design has been designed, built and tested. With the exception of the input field effect transistor (FET), the circuit is constructed using bipolar components. In this paper the design philosophy and measured performance characteristics of the circuit are described.

  11. Development of a Cryogenic Radiation Detector for Mapping Radio Frequency Superconducting Cavity Field Emissions

    CERN Document Server

    Dotson, Danny W

    2005-01-01

    There is a relationship between field emissions in a Super Conducting RF cavity and the production of radiation (mostly X-rays). External (room temperature) detectors are shielded from the onset of low energy X-rays by the vacuum and cryogenic stainless steel module walls. An internal measuring system for mapping field emissions would assist scientists and engineers in perfecting surface deposition and acid washing module surfaces. Two measurement systems are undergoing cryogenic testing at JLab. One is an active CsI photodiode array and the second is an X-ray film camera. The CsI array has operated sucessfully in a cavity in liquid Helium but saturated at higher power due to scattering in the cavity. A shield with an aperature similar to the X-ray film detector is being designed for the next series of tests which will be completed before PAC-05.

  12. Advances in the project about Pin type silicon radiation detectors; Avances en el proyecto sobre detectores de radiacion de silicio tipo PIN

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez F, J. [Instituto Nacional de Investigaciones Nucleares, Laboratorio de Detectores de Radiacion, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Cerdeira, A.; Aceves, M.; Diaz, A.; Estrada, M.; Rosales, P.; Cabal, A.E.; Montano L, M.; Leyva, A

    1998-07-01

    The obtained advances in the collaboration project ININ-CINVESTAV about development of Pin type semiconductor radiation detectors here are presented. It has been characterized the response to different types of radiation made in CINVESTAV and INAOE. Measurements have been realized with different types of sensitive to charge preamplifiers determining the main characteristics which must be executed to be able to be employed with low capacitance detectors. As applications it has been possible to measure the irradiation time in a mammography machine and X-ray energy spectra have been obtained in the order of 14 KeV, with 4 KeV at ambient temperature. The future actions of project have been indicated and the possible applications of these detectors. (Author)

  13. Performance of radiation-hard HV/HR CMOS sensors for the ATLAS inner detector upgrades

    Science.gov (United States)

    Liu, J.; Barbero, M.; Bilbao De Mendizabal, J.; Breugnon, P.; Godiot-Basolo, S.; Pangaud, P.; Rozanov, A.

    2016-03-01

    A major upgrade (Phase II Upgrade) to the Large Hadron Collider (LHC), scheduled for 2022, will be brought to the machine so as to extend its discovery potential. The upgraded LHC, called High-Luminosity LHC (HL-LHC), will run with a nominal leveled instantaneous luminosity of 5×1034 cm-2s-1, more than twice the expected luminosity. This unprecedented luminosity will result in higher occupancy and background radiations, which will request the design of a new Inner Tracker (ITk) which should have higher granularity, reduced material budget and improved radiation tolerance. A new pixel sensor concept based on High Voltage and High Resistivity CMOS (HV/HR CMOS) technology targeting the ATLAS inner detector upgrade is under exploration. With respect to the traditional hybrid pixel detector, the HV/HR CMOS sensor can potentially offer lower material budget, reduced pixel pitch and lower cost. Several prototypes have been designed and characterized within the ATLAS upgrade R&D effort, to investigate the detection and radiation hardness performance of various commercial technologies. An overview of the HV/HR CMOS sensor operation principle is described in this paper. The characterizations of three prototypes with X-ray, proton and neutron irradiation are also given.

  14. Radiation-hard active CMOS pixel sensors for HL-LHC detector upgrades

    Science.gov (United States)

    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.

  15. Radiation hardness and precision timing study of Silicon detectors for the CMS High Granularity Calorimeter (HGC)

    CERN Document Server

    E. Curras; C. Gallrapp; L. Gray; M. Mannelli; P. Meridiani; M. Moll; S. Nourbakhsh; C. Scharf; P. Silva; G. Steinbrueck; T. Tabarelli de Fatis; I. Vila

    2016-01-01

    The high luminosity upgraded LHC or Phase-II is expected to increase the instantaneous luminosity by a factor of 10 beyond the LHC's design value, expecting to deliver 250 fb^−1 per year for a further 10 years of operation. Under these conditions the performance degradation due to integrated radiation dose will need to be addressed. The CMS collaboration is planning to upgrade the forward calorimeters. The replacement is called the High Granularity Calorimeter (HGC) and it will be realized as a sampling calorimeter with layers of silicon detectors interleaved. The sensors will be realized as pad detectors with sizes of less that ∼1.0 cm^2 and an active thickness between 100 and 300 μm depending on the position, respectively, the expected radiation levels. For an integrated luminosity of 3000 fb^−1, the electromagnetic calorimetry will sustain integrated doses of 1.5 MGy (150 Mrads) and neutron fluences up to 10^16 neq/cm^2. A radiation tolerance study after neutron irradiation of 300, 200, and 100 μ...

  16. Influence of solvothermal synthesis conditions in BiSI nanostructures for application in ionizing radiation detectors

    Science.gov (United States)

    Aguiar, I.; Mombrú, M.; Pérez Barthaburu, M.; Bentos Pereira, H.; Fornaro, L.

    2016-02-01

    BiSI belongs to the A V B VI C VII chalcohalides group of compounds. These compounds show several interesting properties such as ferroelectricity, piezoelectricity along the c axis, and photoconductivity. Moreover, BiSI is a potential semiconductor material for room-temperature gamma and x-ray detection, given its band gap of 1.57 eV and its high density, 6.41 g cm-3. In this work we present BiSI nanostructures synthesized by the solvothermal method with the intention of using them for ionizing radiation detection. The solvent was varied to study its influence in morphology, particle size and size distribution. Three different conditions were tested, using either water, monoethylene glycol and a mixture of both solvents. Nanostructures were characterized by XRD to determine the phase obtained and reaction completeness; TEM was used to observe nanostructures morphology, size, size distribution and crystallinity; and finally FT-IR diffuse reflectance was used to study monoethylene glycol presence in the samples. Nanorods in the range of 100-200 nm width were obtained in all samples, but round nanoparticles of around 10 nm in diameter were also detected in samples synthesized only with monoethylene glycol. Samples synthesized in monoethylene glycol were used to fabricate pellets to construct detectors. The detectors responded to ionizing radiation and a resistivity in the order of 1013 Ω cm was estimated. This work proposes, to our knowledge, the first study of BiSI for its application in ionizing radiation detection.

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

    Institute of Scientific and Technical Information of China (English)

    HAO YongQiang; XIAO Zuo; ZOU Hong; ZHANG DongHe

    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 to show the general features of MeV electrons and protons along a solar synchronous orbit at an altitude of 780 km. This height is in the bottom region of the Earth's radiation belts. Detectors are inside the satellite cabinet and such continuous monitoring of particle radiation environment inside a satellite has seldom conducted so far. After a proper and careful treatment, it is indicated that the data inside satellite are well correlated with the radiation environment outside. Besides the agreement of the general distribution characteristics of energetic electrons and protons with similar observations from other satellites, attention is particularly paid to the disturbed conditions. Variations of particle fluxes are closely related with solar proton events, in general, electron fluxes of outer belt are well correlated with Dst index after three days' delay while the electron injection occurred almost at the same day during great magnetic storms. It is confirmed that both energetic electrons and protons appear in the Polar Cap region only after the solar proton events.

  18. Response of a hybrid pixel detector (MEDIPIX3) to different radiation sources for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Chumacero, E. Miguel; De Celis Alonso, B.; Martínez Hernández, M. I.; Vargas, G.; Moreno Barbosa, E., E-mail: emoreno.emb@gmail.com [Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Rio Verde, Puebla (Mexico); Moreno Barbosa, F. [Hospital General del Sur Hospital de la Mujer, Puebla (Mexico)

    2014-11-07

    The development in semiconductor CMOS technology has enabled the creation of sensitive detectors for a wide range of ionizing radiation. These devices are suitable for photon counting and can be used in imaging and tomography X-ray diagnostics. The Medipix[1] radiation detection system is a hybrid silicon pixel chip developed for particle tracking applications in High Energy Physics. Its exceptional features (high spatial and energy resolution, embedded ultra fast readout, different operation modes, etc.) make the Medipix an attractive device for applications in medical imaging. In this work the energy characterization of a third-generation Medipix chip (Medipix3) coupled to a silicon sensor is presented. We used different radiation sources (strontium 90, iron 55 and americium 241) to obtain the response curve of the hybrid detector as a function of energy. We also studied the contrast of the Medipix as a measure of pixel noise. Finally we studied the response to fluorescence X rays from different target materials (In, Pd and Cd) for the two data acquisition modes of the chip; single pixel mode and charge summing mode.

  19. Performance of radiation-hard HV/HR CMOS sensors for the ATLAS inner detector upgrades

    International Nuclear Information System (INIS)

    A major upgrade (Phase II Upgrade) to the Large Hadron Collider (LHC), scheduled for 2022, will be brought to the machine so as to extend its discovery potential. The upgraded LHC, called High-Luminosity LHC (HL-LHC), will run with a nominal leveled instantaneous luminosity of 5×1034 cm−2s−1, more than twice the expected luminosity. This unprecedented luminosity will result in higher occupancy and background radiations, which will request the design of a new Inner Tracker (ITk) which should have higher granularity, reduced material budget and improved radiation tolerance. A new pixel sensor concept based on High Voltage and High Resistivity CMOS (HV/HR CMOS) technology targeting the ATLAS inner detector upgrade is under exploration. With respect to the traditional hybrid pixel detector, the HV/HR CMOS sensor can potentially offer lower material budget, reduced pixel pitch and lower cost. Several prototypes have been designed and characterized within the ATLAS upgrade R and D effort, to investigate the detection and radiation hardness performance of various commercial technologies. An overview of the HV/HR CMOS sensor operation principle is described in this paper. The characterizations of three prototypes with X-ray, proton and neutron irradiation are also given

  20. Testing the integrity of packaging radiation shielding by scanning with radiation source and detector

    International Nuclear Information System (INIS)

    This specification deals with the radiological scanning method of inspection for biological shielding (to be used in transport packaging for gamma emitting sources of radiation), of regular thickness, when the sections are to be checked for integrity and homogeneity; it does not establish the adequacy of design. The shielding materials may be lead, iron, steel, heavy alloy (tungsten), and depleted uranium. (author)

  1. Mechanism of Interaction between Ionizing Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Lee, B. H.; Shin, H. S. (and others)

    2008-03-15

    This research project has been carried out jointly with INP (Poland) to develop technologies for 'Mechanism of Interaction between ionizing radiation and chemicals{sup .} Several biological end-points were assessed in experimental organisms such as higher plants, rats, cell lines and yeast cells to establish proper bioassay techniques. The Tradescantia somatic cell mutation assay was carried out, and immunohistochemistry and hormone assays were done in Fisher 344 rats and cell lines to analyse the combined effect of ionizing radiation with mercury chloride. Using the common regularities of combined actions of two factors, a theoretical model was established, and applied to the thermo radiation action and synergism between two chemicals, as well. The model approach made it possible to predict the condition under which the maximum synergism could be attained. The research results were published in high standard journals and presented in the scientific conferences to verify KAERI's current technology level. The experience of collaboration can be used as a fundamental tool for multinational collaboration, and make the role of improving relationship between Korea and Poland.

  2. Mechanism of Interaction between Ionizing Radiation and Chemicals

    International Nuclear Information System (INIS)

    This research project has been carried out jointly with INP (Poland) to develop technologies for 'Mechanism of Interaction between ionizing radiation and chemicals. Several biological end-points were assessed in experimental organisms such as higher plants, rats, cell lines and yeast cells to establish proper bioassay techniques. The Tradescantia somatic cell mutation assay was carried out, and immunohistochemistry and hormone assays were done in Fisher 344 rats and cell lines to analyse the combined effect of ionizing radiation with mercury chloride. Using the common regularities of combined actions of two factors, a theoretical model was established, and applied to the thermo radiation action and synergism between two chemicals, as well. The model approach made it possible to predict the condition under which the maximum synergism could be attained. The research results were published in high standard journals and presented in the scientific conferences to verify KAERI's current technology level. The experience of collaboration can be used as a fundamental tool for multinational collaboration, and make the role of improving relationship between Korea and Poland

  3. III-nitride quantum cascade detector grown by metal organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yu, E-mail: yusong@princeton.edu; Huang, Tzu-Yung; Badami, Pranav; Gmachl, Claire [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08540 (United States); Bhat, Rajaram; Zah, Chung-En [Corning Incorporated, Corning, New York 14831 (United States)

    2014-11-03

    Quantum cascade (QC) detectors in the GaN/Al{sub x}Ga{sub 1−x}N material system grown by metal organic chemical vapor deposition are designed, fabricated, and characterized. Only two material compositions, i.e., GaN as wells and Al{sub 0.5}Ga{sub 0.5}N as barriers are used in the active layers. The QC detectors operates around 4 μm, with a peak responsivity of up to ∼100 μA/W and a detectivity of up to 10{sup 8} Jones at the background limited infrared performance temperature around 140 K.

  4. Investigation of Chemical-Vapour-Deposition Diamond Alpha-Particle Detectors

    Institute of Scientific and Technical Information of China (English)

    GU Bei-Bei; WANG Lin-Jun; ZHANG Ming-Long; XIA Yi-Ben

    2004-01-01

    Diamond films with [100] texture were prepared by a hot-filament chemical vapour deposition technique to fabricate particle detectors. The response of detectors to 5.5 MeV 241 Am particles is studied. The photocurrent increases linearly and then levels off with voltage, and 7hA is obtained at bias voltage of 100 V. The timedependent photocurrent initially increases rapidly and then tends to reach saturation. Furthermore, a little increase of the dark-current after irradiation can be accounted for by the release of the charges captured by the trapping centres at low energy levels during irradiation. An obvious peak of the pulse height distribution can be observed, associated with the energy of 5.5 MeV.

  5. Integration of an opto-chemical detector based on group III-nitride nanowire heterostructures.

    Science.gov (United States)

    Kleindienst, R; Becker, P; Cimalla, V; Grewe, A; Hille, P; Krüger, M; Schörmann, J; Schwarz, U T; Teubert, J; Eickhoff, M; Sinzinger, S

    2015-02-01

    The photoluminescence intensity of group III nitrides, nanowires, and heterostructures (NWHs) strongly depends on the environmental H(2) and O(2) concentration. We used this opto-chemical transducer principle for the realization of a gas detector. To make this technology prospectively available to commercial gas-monitoring applications, a large-scale laboratory setup was miniaturized. To this end the gas-sensitive NWHs were integrated with electro-optical components for optical addressing and read out within a compact and robust sensor system. This paper covers the entire realization process of the device from its conceptual draft and optical design to its fabrication and assembly. The applied approaches are verified with intermediate results of profilometric characterizations and optical performance measurements of subsystems. Finally the gas-sensing capabilities of the integrated detector are experimentally proven and optimized.

  6. Photodiode radiation hardness, lyman-alpha emitting galaxies and photon detection in liquid argon neutrino detectors

    Science.gov (United States)

    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

  7. Investigation of DEPFET as vertex detector at ILC. Intrinsic properties, radiation hardness and alternative readout schemes

    International Nuclear Information System (INIS)

    The International Linear Collider (ILC) is supposed to be the next generation lepton collider. The detectors at ILC are intended to be precision instruments improving the performance in impact parameter (IP), momentum and energy resolution significantly compared to previous detectors at lepton colliders. To achieve this goal it is necessary to develop new detector technologies or pushing existing technologies to their technological edges. Regarding the Vertex detector (VTX) this implies challenges in resolution, material budget, power consumption and readout speed. A promising technology for the Vertex detector is the Depleted Field Effect Transistor (DEPFET). The DEPFET is a semiconductor device with in-pixel ampli cation integrated on a fully depleted bulk. This allows building detectors with intrinsically high SNR due to the large sensitive volume and the small input capacitance at the rst ampli er. To reach the ambitious performance goals it is important to understand its various features: clear performance, internal amplification, noise and radiation hardness. The intrinsic noise is analyzed, showing that the contribution of the DEPFET is below 50 e- at the required speed. Moreover it is possible to show that the internal ampli cation could be further improved to more than 1nA/e- using the standard DEPFET technology. The clear performance is investigated on matrix level utilizing a dedicated setup for single pixel testing which allows direct insight into the DEPFET operation, without the complexity of the full readout system. It is possible to show that a full clear could be achieved with a voltage pulse of 10 V. Furthermore a novel clear concept - the capacitive coupled clear gate - is demonstrated. The radiation hardness is studied with respect to the system performance utilizing various irradiations with ionizing and non ionizing particles. The impact on the bulk as well as the interface damage is investigated. Up to now the readout is performed with

  8. Investigation of DEPFET as vertex detector at ILC. Intrinsic properties, radiation hardness and alternative readout schemes

    Energy Technology Data Exchange (ETDEWEB)

    Rummel, Stefan

    2009-07-20

    The International Linear Collider (ILC) is supposed to be the next generation lepton collider. The detectors at ILC are intended to be precision instruments improving the performance in impact parameter (IP), momentum and energy resolution significantly compared to previous detectors at lepton colliders. To achieve this goal it is necessary to develop new detector technologies or pushing existing technologies to their technological edges. Regarding the Vertex detector (VTX) this implies challenges in resolution, material budget, power consumption and readout speed. A promising technology for the Vertex detector is the Depleted Field Effect Transistor (DEPFET). The DEPFET is a semiconductor device with in-pixel ampli cation integrated on a fully depleted bulk. This allows building detectors with intrinsically high SNR due to the large sensitive volume and the small input capacitance at the rst ampli er. To reach the ambitious performance goals it is important to understand its various features: clear performance, internal amplification, noise and radiation hardness. The intrinsic noise is analyzed, showing that the contribution of the DEPFET is below 50 e{sup -} at the required speed. Moreover it is possible to show that the internal ampli cation could be further improved to more than 1nA/e{sup -} using the standard DEPFET technology. The clear performance is investigated on matrix level utilizing a dedicated setup for single pixel testing which allows direct insight into the DEPFET operation, without the complexity of the full readout system. It is possible to show that a full clear could be achieved with a voltage pulse of 10 V. Furthermore a novel clear concept - the capacitive coupled clear gate - is demonstrated. The radiation hardness is studied with respect to the system performance utilizing various irradiations with ionizing and non ionizing particles. The impact on the bulk as well as the interface damage is investigated. Up to now the readout is performed

  9. Methodology optimization of the thallium bromide crystal preparation for application as a radiation detector

    International Nuclear Information System (INIS)

    In this work, TlBr crystals have been purified and grown by the Repeated Bridgman method from commercial TlBr materials and characterized to be used as radiation detectors. To evaluate the purification efficiency, studies on the impurity concentration decrease were performed after each growth, analyzing the trace impurities by inductively coupled plasma mass spectroscopy (ICP-MS). A significant decrease of the concentration of impurities in function of the purification number was observed. The grown crystals presented good crystalline quality according to the results of the x-ray diffraction analysis. To evaluate the crystals to be used as a semiconductor detector, measurements of the resistivity and the pulse height under 241Am gamma rays were carried out. The radiation response was strongly dependent on the crystal purity. The Repeated Bridgman technique showed to be effective to reduce the concentration of impurities and to improve the TlBr crystal quality to be used as a radiation semiconductor detector. A compartmental model was proposed to fit the concentration/segregation of impurities in function of the Bridgman growth step number. This compartmental model is defined by differential equations and can be used to calculate the rate of migration of impurities. It proved to be a useful tool in predicting the number of Bridgman growth repetitions necessary to achieve the desired impurity concentration. The difference of the impurity migration rates between the crystals grown, using salts from different origins, was significant. Therefore, the choice of the starting salt should be performed experimentally, regardless of the statement nominal purity. (author)

  10. High spatial resolution radiation detectors based on hydrogenated amorphous silicon and scintillator

    International Nuclear Information System (INIS)

    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 ∼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 micros. 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

  11. An assessment of radiation damage in space-based germanium detectors due to solar proton events

    International Nuclear Information System (INIS)

    Radiation effects caused by solar proton events will be a common problem for many types of sensors on missions to the inner solar system because of the long cruise phases coupled with the inverse square scaling of solar particle events. As part of a study in support of the BepiColombo mission to Mercury we have undertaken a comprehensive series of tests to assess these effects on a wide range of sensors. In this paper, we report on the measurements on a large volume coaxial Ge detector which was exposed to simulated solar proton spectra of integrated fluences 8x108, 6x109 and 6x1010protonscm-2. After each irradiation the detectors performance was accessed in terms of energy resolution, efficiency and activation. The detector was then annealed and the measurements repeated before the next irradiation. The minimum operational performance criteria were based on the resolution and efficiency requirements necessary to detect and separate specific radioisotope emission lines from a planetary regolith. Specifically that the energy resolution be restored to 5 keV FWHM at 1332 keV and the detection efficiency be degraded to no more than 10% of its pre-irradiation value. The key conclusion of this study is that even after a modest solar proton event the detector requires extensive annealing. After exposure to an event of integral fluence ∼8x108protonscm-2 this amounts to ∼1 week duration at 1000C, whereas for a fluence of ∼6x1010protonscm-2, the detector requires 3.5 months of annealing to satisfy the minimum operational performance requirements and 4.5 months to return the energy resolution to <3keV FWHM at 1332 keV. As a consequence such an instrument will require constant, planned and active management throughout its operational lifetime. The impact on spacecraft operations including resource management therefore needs careful consideration

  12. Applications of synchrotron radiation to Chemical Engineering Science: Workshop report

    International Nuclear Information System (INIS)

    This report contains extended abstracts that summarize presentations made at the Workshop on Applications of Synchrotron Radiation to Chemical Engineering Science held at Argonne National Laboratory (ANL), Argonne, IL, on April 22--23, 1991. The talks emphasized the application of techniques involving absorption fluorescence, diffraction, and reflection of synchrotron x-rays, with a focus on problems in applied chemistry and chemical engineering, as well as on the use of x-rays in topographic, tomographic, and lithographic procedures. The attendees at the workshop included experts in the field of synchrotron science, scientists and engineers from ANL, other national laboratories, industry, and universities; and graduate and undergraduate students who were enrolled in ANL educational programs at the time of the workshop. Talks in the Plenary and Overview Session described the status of and special capabilities to be offered by the Advanced Photon Source (APS), as well as strategies and opportunities for utilization of synchrotron radiation to solve science and engineering problems. Invited talks given in subsequent sessions covered the use of intense infrared, ultraviolet, and x-ray photon beams (as provided by synchrotrons) in traditional and nontraditional areas of chemical engineering research related to electrochemical and corrosion science, catalyst development and characterization, lithography and imaging techniques, and microanalysis

  13. Radiation-chemical desulfurization and denitrification of flue gases

    International Nuclear Information System (INIS)

    Radiation-chemical desulfurization and denitrification of flue gases is a highly promising method for removing SO2 and NOx from gases emerging from the combustion of coal and heating oils, from the heat treatment of ores, etc. Its principle is as follows. Into the flue gases, freed from solid particles, are injected a suitable base and water. The gaseous mixture, or aerosol, enters a reactor in which it is exposed to accelerated electrons. The latter thermalize gradually and their energy is transferred to the surrounding molecules, whereby radiolysis is initiated. The primary products are positively charged ions, secondary electrons, excited states of molecules and free radicals. Some amount of negatively charged ions is also formed. These particles enter into fast reactions with the molecules, and as a result, SO2 and NOx are oxidized and transformed into acids (H2SO4, HNO3) which ultimately react with the base to give salts as the final products. In suitable conditions the final products are formed in the solid state and can be removed by filtration, electrostatic separation, etc. The topic is treated in detail with respect to its physico-chemical and radiation-chemical principles as well as its characteristics and technical implementation, and a survey of research, demonstration and pilot-plant units aimed at its industrial application is given. The method is considered promising in Czechoslovak conditions and deserves attention of technologists as well as national economy experts. (P.A.). 7 figs., 3 tabs., 49 refs

  14. Development of a cryogenic radiation detector for mapping radio frequency superconducting cavity field emissions

    Energy Technology Data Exchange (ETDEWEB)

    Danny Dotson; John Mammosser

    2005-05-01

    Field emissions in a super conducting helium cooled RF cavity and the production of radiation (mostly X-Rays) have been measured externally on cryomodules at Jefferson Lab since 1991. External measurements are limited to radiation energies above 100 keV due to shielding of the stainless steel cryogenic body. To measure the onset of and to map field emissions from a superconducting cavity requires the detecting instrument be inside the shield and within the liquid Helium. Two possible measurement systems are undergoing testing at JLab. A CsI detector array set on photodiodes and an X-Ray film camera with a fixed aperture. Several devices were tested in the cell with liquid Helium without success. The lone survivor, a CsI array, worked but saturated at high power levels due to backscatter. The array was encased in a lead shield with a slit opening set to measure the radiation emitted directly from the cell eliminating a large portion of the backscatter. This is a work in progress and te sting should be complete before the PAC 05. The second system being tested is passive. It is a shielded box with an aperture to expose radiation diagnostic film located inside to direct radiation from the cell. Developing a technique for mapping field emissions in cryogenic cells will assist scientists and engineers in pinpointing any surface imperfections for examination.

  15. 1980, a revolution in silicon detectors, from energy spectrometer to radiation imager: Some technical and historical details

    International Nuclear Information System (INIS)

    Silicon nuclear particle detectors were introduced just 50 years ago, after single crystal manufacturing was mastered. A major change took place around 1980 when the 'planar' Metal Oxide Semiconductor (MOS) technology developed in microelectronics was systematically applied also in detector construction. With the simultaneous introduction of matched readout chips this eventually would lead to pixelized matrix detectors that function as radiation imaging devices. The critical contributions to this revolution by Josef Kemmer and Paul Burger are described. Performance of the segmented planar technology detectors improved significantly in comparison with the earlier spectrometric diodes. With efficient industrial support the use of silicon detectors in many new applications has become possible and detector systems with a sensitive area of several tens to >100m2 have been constructed recently

  16. The role of nanostructures and quantum dots in detectors and solar cells for radiation hardened space applications

    Science.gov (United States)

    Taylor, Edward W.

    2006-08-01

    Highly efficient IR detectors and photo-voltaic solar cells that incorporate nanotechnology composed of nanostructures and nanoparticles (including quantum dots) will play an important role in advanced photonic space applications. While the development of Si-based solar cells has successfully evolved into an efficient and economical technology these devices are predicted to soon reach their theoretical 29% limit efficiency. Alternative organic/polymer solar cells and IR detectors incorporating quantum dots and various nanoparticle or nanostructure materials are emerging which are expected to eventually outperform current state-of-the-art detectors and solar cell devices. By tailoring the QD design wavelength-optimized detectors and detector arrays operating over the UV-IR range can be realized. Specific examples for achieving near-IR photovoltaic and photoconductive detectors with high quantum efficiencies are presented along with brief examples of empirical data reported for assessing the radiation resistance of QD nanocrystalline devices for application in space environments.

  17. Improved spectrometric performance of CdTe radiation detectors in a p-i -n design

    OpenAIRE

    Niraula, Madan; Mochizuki, Daisuke; Aoki, Toru; Hatanaka, Yoshinori; Tomita, Yasuhiro; Nihashi, Tokuaki; ニラウラ, マダン

    1999-01-01

    CdTe radiation detectors were fabricated using a p-i-n design and a significant improvement in the spectral properties was obtained during room temperature operation. An iodine doped n-CdTe layer was grown on the Te faces of the (111) oriented high resistivity CdTe crystals at the low substrate temperature of 150°C. An aluminum electrode was evaporated on the n-CdTe side for the n-type contact, while a gold electrode on the opposite side acted as the p-type contact. Very low leakage currents,...

  18. Improved Growth Methods for LaBr3 Scintillation Radiation Detectors

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S

    2011-05-01

    The objective is to develop advanced materials for deployment as high-resolution gamma ray detectors. Both LaBr3 and CeBr3 are advanced scintillation materials, and will be studied in this research. Prototype devices, in collaboration Sandia National Laboratories, will be demonstrated along with recommendations for mass production and deployment. It is anticipated that improved methods of crystal growth will yield larger single crystals of LaBr3 for deployable room-temperature operated gamma radiation spectrometers. The growth methods will be characterized. The LaBr3 and CeBr3 scintillation crystals will be characterized for light yield, spectral resolution, and for hardness.

  19. The influence of radiation on the chemical constituents of food

    International Nuclear Information System (INIS)

    Six major components are necessary in an adequate diet, viz. fats, carbohydrates, proteins, vitamins, minerals and water. Wholesomeness evaluation may be divided into two categories: (a) The monitoring of any change in nutritional content. (b) The examination of the possible formation of toxic degradation products. Investigations take the form of animal feeding studies or chemical monitoring. Very few foods do not have water as a significant component. The major radiolytic products of water are hydroxyl radicals and hydrated electrons. The degradation products of lipids caused by ionizing radiation, autoxidation and thermal processing are very similar. No untoward effects have been noted in laboratory animals fed irradiated lipid-containing foods. Degradation of polysaccharides by ionising radiation yields simpler carbohydrates. Simpler carbohydrates are not significantly degraded by commercially recommended doses of radiation. Most of the radiolytic products are carbonylic in character. Products formed in irradiated fruits and vegetables have been shown to be non-toxic. No significant changes could be detected in the nutritiousness of a variety of proteins. No vitamin deficiency diseases could be detected in laboratory animals receiving irradiated fruits and vegetables. Minerals are unaffected, nutritionally, by ionising radiation

  20. Biological efficiency of interaction between various radiation and chemicals

    International Nuclear Information System (INIS)

    This research project has been carried out jointly with INP (Poland) to develop technologies to assess the biological efficiency of interaction between radiation and chemicals. Through the cooperative project, KAERI and INP have established wide variety of bioassay techniques applicable to radiation bioscience, human monitoring, molecular epidemiology and environmental science. The joint experiment, in special, made it possible to utilize the merits of both institutes and to upgrade and verify KAERI's current technology level. All results of the cooperative research will be jointly published in high standard scientific journals listed in the Science Citation Index (SCI), which can make the role of fundamental basis for improving relationship between Korea and Poland. Research skills such as Trad-MCN assay, SCGE assay, immunohistochemical assay and molecular assay developed through joint research will be further elaborated and will be continuously used for the collaboration between two institutes

  1. Wide Band-Gap Semiconductor Radiation Detectors: Science Fiction, Horror Story, or Headlines (460th Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    James, Ralph (BNL Nonproliferation and National Security Department)

    2010-08-18

    With radiation constantly occurring from natural sources all around us -- from food, building materials, and rays from the sun, to name a few -- detecting radiotracers for medical procedures and other radiation to keep people safe is not easy. In order to make better use of radiation to diagnose or treat certain health conditions, or to track radiological materials being transported, stored, and used, the quest is on to develop improved radiation detectors. James gives a brief introduction on radiation detection and explain how it is used in applications ranging from medical to homeland security. He then discusses how new materials and better ways to analyze them here at the National Synchrotron Light Source (NSLS) and the future NSLS-II will lead to a new class of radiation detectors that will provide unprecedented advances in medical and industrial imaging, basic science, and the nonproliferation of nuclear materials.

  2. Optimization of radiation-chemical process of trichloroethylene oxidation

    International Nuclear Information System (INIS)

    Kinetics of trichloroethylene (TCE) oxidation under the effect of gamma-irradiation is investigated. It is shown that the reaction of TCE oxidation proceeds according to the chain mechanism. At the temperature of 60 deg C in the dose rate range from 1.1015 to 1.5x1016 eV(cm3xs) radiation-chemical yield changes from 1.5x104 to 5x103 molecules/100 eV. It is found that the reaction rate practically does not depend upon oxygen concentration and is directly proportional to the TCE concentration and the dose rate. The process optimization is studied

  3. Mechanism of radiation-chemical and pyrolytic transformations in lexan

    OpenAIRE

    Roustam Aliev; Rafael Navarro-González

    2006-01-01

    We report here a new approach to study the mechanism of radiation-chemical transformations in polymeric materials based on the combined analysis of radiolytic gases, and pyrolytic products from preirradiated polymers by flash pyrolysis coupled to gas chromatography –Fourier transformed infrared spectroscopy– mass spectrometry with electron impact mode (GC-FTIR-MS). Lexan® (bisphenol-A polycarbonate) was studied in the dose range from 0.125 to 1.0 MGy. Lexan irradiation was accompanied by the ...

  4. Monolithic Silicon Photodetector - Detector of Ionizing Radiation Based on Functional Integrated MOS Structures

    Directory of Open Access Journals (Sweden)

    S.A. Legotin

    2014-07-01

    Full Text Available This paper describes the principle of operation, construction, architecture and fabrication of a new type of monolithic silicon coordinate photodetector - detector of optical and ionizing radiation (MSCP on the basis of functional integrated MOS structures. The analytical estimation of electrophysical characteristics MSCP is given. It is shown that MSCP is a specialized monolithic silicon VLSI containing two-dimensional pixel array with high and low voltage functionally integrated structures (FIS and peripheral electronic circuits of amplification and signal processing matrix. Estimations and presents comparative characteristics are presented. They show potential MSCP possibilities for registration of optical and ionizing radiation. Experimental results of α-particles and electrons registration. The possible areas of application, with the possibility of its use in a wide X-ray panels medical supplies, X-rays, etc are considered.

  5. Radiation hardness of plastic scintillators for the Tile Calorimeter of the ATLAS detector

    CERN Document Server

    Jivan, Harshna; The ATLAS collaboration

    2014-01-01

    The Tile Calorimeter of the ATLAS detector, is a hadronic calorimeter responsible for detecting hadrons as well as accommodating for the missing transverse energy that result from the p-p collisions within the LHC. Plastic scintillators form an integral component of this calorimeter due to their ability to undergo prompt fluorescence when exposed to ionising particles. The scintillators employed are specifically chosen for their properties of high optical transmission and fast rise and decay time which enables efficient data capture since fast signal pulses can be generated. The main draw-back of plastic scintillators however is their susceptibility to radiation damage. The damage caused by radiation exposure reduces the scintillation light yield and introduces an error into the time-of flight data acquired. During Run 1 of the LHC data taking period, plastic scintillators employed within the GAP region between the Tile Calorimeter’s central and extended barrels sustained a significant amount of damage. Wit...

  6. Thin silicon strip detectors for beam monitoring in Micro-beam Radiation Therapy

    CERN Document Server

    Povoli, Marco; Bravin, Alberto; Cornelius, Iwan; Bräuer-Krisch, Elke; Fournier, Pauline; Hansen, Thor-Erik; Kok, Angela; Lerch, Michael; Monakhov, Edouard; Morse, John; Petasecca, Marco; Requardt, Herwig; Rosenfeld, Anatoly; Röhrich, Dieter; Sandaker, Heidi; Salomé, Murielle; Stugu, Bjarne

    2015-01-01

    Microbeam Radiation Therapy (MRT) is an emerging cancer treatment that is currently being developed at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. This technique uses a highly collimated and fractionated X-ray beam array with extremely high dose rate and very small divergence, to benefit from the dose-volume effect, thus sparing healthy tissue. In case of any beam anomalies and system malfunctions, special safety measures must be installed, such as an emergency safety shutter that requires continuous monitoring of the beam intensity profile. Within the 3DMiMic project, a novel silicon strip detector that can tackle the special features of MRT, such as the extremely high spatial resolution and dose rate, has been developed to be part of the safety shutter system. The first prototypes have been successfully fabricated, and experiments aimed to demonstrate their suitability for this unique application have been performed. Design, fabrication and the experimental results as well as any...

  7. Strained-Si modulation doped field effect transistors as detectors of terahertz and sub-terahertz radiation

    Science.gov (United States)

    Rumyantsev, S. L.; Fobelets, K.; Veksler, D.; Hackbarth, T.; Shur, M. S.

    2008-10-01

    Strained-Si modulation doped field effect transistors have been studied as detectors of 0.2 THz and 1.6 THz electromagnetic radiation at room temperature. The difference in the gate voltage dependences for 0.2 THz and 1.6 THz radiation and spatial pattern of the transistor response to focused 1.6 THz radiation confirms that the mechanism of detection is linked to the excitations of the two-dimensional electrons in the device channel.

  8. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    Science.gov (United States)

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  9. Development of novel semiconductor detectors for the detection of ionizing radiation

    International Nuclear Information System (INIS)

    The present thesis treats the development of novel energy- and position-resolving semiconductor detectors: Fully depletable pn CCD's. In experiments of high-energy physics they are suited as highly resolving position-sensitive detectors for minimally ionizing particles. In nuclear and atomic physics they can be applied as position-resolving energy spectrometers. Increasing interest detectors of this type find also at synchrotron-radiation sources with photon energies from 20 eV to 50 keV. As focal instruments of X-ray telescopes they are in astrophysical measurements in an energy range from 100 eV to 15 keV of use. The required accuracy in the energy measurement amounts to 100 eV (FWHM) at an X-ray energy of 1 keV, at a simultaneous precision of the position determination of 50 μm. The measurement results which are here presented on the first fully depletable CCD's show that the components posses the potential to fulfill these requirements. (orig.)

  10. Material analysis of the CZT crystal grown for a radiation detector

    Science.gov (United States)

    Kim, Han Soo; Jeong, Manhee; Kim, Young Soo; Kim, Dong Jin; Choi, Hyo Jeong

    2015-01-01

    Room-temperature semiconductor radiation detectors, such as CdZnTe (CZT) and CdTe detectors, are being developed and grown worldwide owing to their high performances as a gamma-ray detector. A 2″ CZT ingot was grown using a 6-zone low-pressure (LP) Bridgman furnace at the Korea Atomic Energy Research Institute (KAERI). To increase the resistivity, indium (In) was doped at 5 ppm and 7 ppm, respectively. Material analysis results obtained by using inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffractometry (XRD), and an infrared (IR) scope system were compared with the I-V results with respect to the location on the grown ingots and doping concentration. A (1,1,1) orientation and 1.41 × 1011 Ω·cm resistivity were measured in the middle part of the ingot. In addition, Te inclusions were also homogeneously shown. The variation in the I-V characteristics with respect to the preparation conditions of the crystals was also addressed.

  11. Sub-nanosecond time resolution detector based on APD for Synchrotron Radiation ultrafast experiments

    CERN Document Server

    Li, Zhen-jie; Liu, Peng; Wang, Shan-feng; Dong, Wei-wei; Zhou, Yang-fan

    2015-01-01

    Synchrotron radiation light sources produce intense beam of X-ray with ultra-short pulse and nanosecond period. This of-fers the opportunities for the time resolution experiments. Achieving higher counting rate and faster arriving time is diffi-cult for common detectors. But avalanche photodiodes (APD) based on silicon which have been commercially available1 with large active areas (e.g.10mmx10mm@ Perkin-Elmer Inc.) could satisfy the demands due to their good time resolution, low noise and large area.We investigate the high counting rate and nanosecond time resolution detector with APD. The detector's fast amplifier was designed with the gain of about 60dB (1000). The amplifier included with three stages RF-preamplifier using MAR6+ chip5 for the carefully controlling the circuit oscillation. Some measures have been taken for the preamplifiers good performance such as using resistance net between RF-preamplifier chip and the isolation of high voltage circuit from the preamplifier. The time resolution of the pr...

  12. Applications of pixellated GaAs X-ray detectors in a synchrotron radiation beam

    CERN Document Server

    Watt, J; Campbell, M; Mathieson, K; Mikulec, B; O'Shea, V; Passmore, M S; Schwarz, C; Smith, K M; Whitehill, C

    2001-01-01

    Hybrid semiconductor pixel detectors are being investigated as imaging devices for radiography and synchrotron radiation beam applications. Based on previous work in the CERN RD19 and the UK IMPACT collaborations, a photon counting GaAs pixel detector (PCD) has been used in an X-ray powder diffraction experiment. The device consists of a 200 mu m thick SI-LEC GaAs detector patterned in a 64*64 array of 170 mu m pitch square pixels, bump-bonded to readout electronics operating in single photon counting mode. Intensity peaks in the powder diffraction pattern of KNbO/sub 3/ have been resolved and compared with results using the standard scintillator, and a PCD predecessor (the Omega 3). The PCD shows improved speed, dynamic range, 2-D information and comparable spatial resolution to the standard scintillator based systems. It also overcomes the severe dead time limitations of the Omega 3 by using a shutter based acquisition mode. A brief demonstration of the possibilities of the system for dental radiography and...

  13. Applications of pixellated GaAs X-ray detectors in a synchrotron radiation beam

    Energy Technology Data Exchange (ETDEWEB)

    Watt, J. E-mail: j.watt@physics.gla.ac.uk; Bates, R.; Campbell, M.; Mathieson, K.; Mikulec, B.; O' Shea, V.; Passmore, M-S.; Schwarz, C.; Smith, K.M.; Whitehill, C

    2001-03-11

    Hybrid semiconductor pixel detectors are being investigated as imaging devices for radiography and synchrotron radiation beam applications. Based on previous work in the CERN RD19 and the UK IMPACT collaborations, a photon counting GaAs pixel detector (PCD) has been used in an X-ray powder diffraction experiment. The device consists of a 200 {mu}m thick SI-LEC GaAs detector patterned in a 64x64 array of 170 {mu}m pitch square pixels, bump-bonded to readout electronics operating in single photon counting mode. Intensity peaks in the powder diffraction pattern of KNbO{sub 3} have been resolved and compared with results using the standard scintillator, and a PCD predecessor (the {omega}3). The PCD shows improved speed, dynamic range, 2-D information and comparable spatial resolution to the standard scintillator based systems. It also overcomes the severe dead time limitations of the {omega}3 by using a shutter based acquisition mode. A brief demonstration of the possibilities of the system for dental radiography and image processing are given, showing a marked reduction in patient dose and dead time compared with film.

  14. Applications of pixellated GaAs X-ray detectors in a synchrotron radiation beam

    Science.gov (United States)

    Watt, J.; Bates, R.; Campbell, M.; Mathieson, K.; Mikulec, B.; O'Shea, V.; Passmore, M.-S.; Schwarz, C.; Smith, K. M.; Whitehill, C.; XIMAGE Project

    2001-03-01

    Hybrid semiconductor pixel detectors are being investigated as imaging devices for radiography and synchrotron radiation beam applications. Based on previous work in the CERN RD19 and the UK IMPACT collaborations, a photon counting GaAs pixel detector (PCD) has been used in an X-ray powder diffraction experiment. The device consists of a 200 μm thick SI-LEC GaAs detector patterned in a 64×64 array of 170 μm pitch square pixels, bump-bonded to readout electronics operating in single photon counting mode. Intensity peaks in the powder diffraction pattern of KNbO 3 have been resolved and compared with results using the standard scintillator, and a PCD predecessor (the Ω3). The PCD shows improved speed, dynamic range, 2-D information and comparable spatial resolution to the standard scintillator based systems. It also overcomes the severe dead time limitations of the Ω3 by using a shutter based acquisition mode. A brief demonstration of the possibilities of the system for dental radiography and image processing are given, showing a marked reduction in patient dose and dead time compared with film.

  15. Monte Carlo simulation for the electron cascade due to gamma rays in semiconductor radiation detectors

    International Nuclear Information System (INIS)

    A Monte Carlo code was developed for simulating the electron cascade in radiation detector materials. The electron differential scattering cross sections were derived from measured electron energy-loss and optical spectra, making the method applicable for a wide range of materials. The detector resolution in a simplified model system shows dependence on the bandgap, the plasmon strength and energy, and the valence band width. In principle, these parameters could be optimized to improve detector performance. The intrinsic energy resolution was calculated for three semiconductors: silicon (Si), gallium arsenide (GaAs), and zinc telluride (ZnTe). Setting the ionization thresholds for electrons and holes is identified as a critical issue, as this strongly affects both the average electron-hole pair energy w and the Fano factor F. Using an ionization threshold from impact ionization calculations as an effective bandgap yields pair energies that are well matched to measured values. Fano factors of 0.091 (Si), 0.100 (GaAs), and 0.075 (ZnTe) were calculated. The Fano factor calculated for silicon using this model was lower than some results from past simulations and experiments. This difference could be attributed to problems in simulating inter-band transitions and the scattering of low-energy electrons.

  16. Monte Carlo simulation for the electron cascade due to gamma rays in semiconductor radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Raman D.; Miranda, Ryan; Rez, Peter [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)

    2012-03-15

    A Monte Carlo code was developed for simulating the electron cascade in radiation detector materials. The electron differential scattering cross sections were derived from measured electron energy-loss and optical spectra, making the method applicable for a wide range of materials. The detector resolution in a simplified model system shows dependence on the bandgap, the plasmon strength and energy, and the valence band width. In principle, these parameters could be optimized to improve detector performance. The intrinsic energy resolution was calculated for three semiconductors: silicon (Si), gallium arsenide (GaAs), and zinc telluride (ZnTe). Setting the ionization thresholds for electrons and holes is identified as a critical issue, as this strongly affects both the average electron-hole pair energy w and the Fano factor F. Using an ionization threshold from impact ionization calculations as an effective bandgap yields pair energies that are well matched to measured values. Fano factors of 0.091 (Si), 0.100 (GaAs), and 0.075 (ZnTe) were calculated. The Fano factor calculated for silicon using this model was lower than some results from past simulations and experiments. This difference could be attributed to problems in simulating inter-band transitions and the scattering of low-energy electrons.

  17. Accumulated-carrier screening effect based investigation for pixellated CdZnTe radiation detector

    International Nuclear Information System (INIS)

    Using the pixellated CdZnTe detector,the radiation imaging experiment for the Rh target X-ray source was accomplished. The experimental results indicate that the response signals of the anode pixels, which distribute over the center irradiated area,are completely shut-off when the tube Jantage is 45 kV and the tube current increases to 20 μA. Moreover, the non-response pixel area expands with the increase of the tube current, and the total event count of the CdZnTe detector reduces obviously. Furthermore, the inner electric potential and electric field distributions of the pixellated CdZnTe detector were simulated based on the Poisson equation. The simulation results reveal that the accumulation of the hole carriers, which results from the extremely low drift ability of the hole carrier, leads to a relatively high space-charge-density area in the CdZnTe bulk when the irradiated photon flux increases to 5 x 105 mm-2·s-1. And thus, the induced signal screen effect of the anode pixels in the center irradiated area is mainly attributed to the distorted electric field which makes electron carriers drift toward the high potential area in the CdZnTe crystal instead of the pixel anodes. (authors)

  18. Design and Implementation of a Detector for High Flux Mixed Radiation Fields

    CERN Document Server

    Kramer, Daniel; Sulc, Miroslav

    2008-01-01

    The main purpose of the LHC Beam Loss Monitoring (BLM) system is the active protection of the LHC accelerators' elements against the quench of superconducting magnets and the damage of equipment caused by the loss of circulating protons. The lost protons initiate a shower of secondary particles, which deposit their energy in the equipment and partly in a radiation detector. If thresholds in the BLM system are exceeded, the circulating LHC beam is directed towards a dump to stop the energy deposition in the fragile equipment. The LHC BLM system will use ionization chambers as standard detectors, and in the areas with very high dose rates Secondary Emission Monitor (SEM) chambers will be employed to increase the dynamic range. The SEM is characterized by a high linearity and accuracy, low sensitivity, fast response and a good radiation tolerance. The emission of electrons from the surface layer of metals by the passage of charged particles is only measurable in a vacuum environment. This requirement leads toget...

  19. Radiation hard silicon detectors - developments by the RD48 (ROSE) collaboration

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

    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 2x10{sup 17} O/cm{sup 3} in the normal detector processing. Systematic investigations have been carried out on various standard and oxygenated silicon diodes with neutron, proton and pion irradiation up to a fluence of 5x10{sup 14} cm{sup -2} (1 MeV neutron equivalent). Major focus is on the changes of the effective doping concentration (depletion voltage). Other aspects (reverse current, charge collection) are covered too and the appreciable benefits obtained with DOFZ silicon in radiation tolerance for charged hadrons are outlined. The results are reliably described by the 'Hamburg model': its application to LHC experimental conditions is shown, demonstrating the superiority of the defect engineered silicon. Microscopic aspects of damage effects are also discussed, including differences due to charged and neutral hadron irradiation.

  20. Development of radiation hard microstrip detectors for the CBM silicon tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Chatterji, Sudeep [GSI, Darmstadt (Germany)

    2010-07-01

    Radiation damage in Silicon microstrip detectors is of the one main concerns for the development of the Silicon Tracking System (STS) in the planned Compressed Baryonic Matter (CBM) experiment at FAIR. The STS will consist of Double Sided Silicon Strip Detectors (DSSD) having pitch around 60 {mu}m, width 20 {mu}m, stereo angle of {+-}7.5{sup 0} on n and p sides with double metallization on either side making it challenging to fabricate.We are using 3-dimensional TCAD simulation tools from SYNOPSYS to carry out process (using Sentaurus Process) and device (using Sentaurus Device) simulations.We have simulated the impact of radiation damage in DSSDs by changing the effective carrier concentration (N{sub eff}) with fluence using the Hamburg model. The change in minority carrier life time has been taken into account using the Kraners model and the Perugia trap model has been used to simulate the traps. We have also extracted macroscopic parameters like Coupling Capacitance, Interstrip Capacitance (both DC and AC), Interstrip Resistance of DSSDs using Mixed Mode simulation (using SPICE with Sentaurus Device) and studied the variation of these parameters with fluence. The simulation results have been compared to the experimental results. We also simulated transients by passing a Heavy Ion through a DSSD and studied the charge collection performance.