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Sample records for frisch-grid cdznte detector

  1. Simulation of the anode structure for capacitive Frisch grid CdZnTe detectors

    Institute of Scientific and Technical Information of China (English)

    MIN Jiahua; SHI Zhubin; QIAN Yongbiao; SANG Wenbin; ZHAO Hengyu; TENG Jianyong; LIU Jishan

    2009-01-01

    CdZnTe (CZT) capacitive Frisch grid detectors can achieve a higher detecting resolution.The anode structure might have an important role in improving the weighting potential distribution of the detectors.In this paper,four anode structures of capacitive Frisch grid structures have been analyzed with FE simulation,based on a 3-dimensional weighting potential analysis.The weighting potential distributions in modified anode devices (Model B,C and D) are optimized compared with a square device (Model A).In model C and D,the abrupt weighting potential can be well modified.However,with increased radius of the circular electrode in Model C the weighting potential platform away from the anode becomes higher and higher and in Model D,the weighting potential does not vary too much.

  2. Hybrid Contacts for CZT Virtual Frisch-grid Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Camarda G.; Bolotnikov, A.E.; Chan, W.; Cui, Y.; Gul R.; Hossain, A.; Kim, K.; Yang, G.; James, R.B.

    2011-08-22

    In our previous design of virtual Frisch-grid CdZnTe (CZT) detectors, the charge drift-lines can be terminated at the side surfaces before the carriers reach the collecting anode; this results in a loss of signal from the interacting events near the detector's edges. Here, we describe our new design for the anode contact that reduces these edge effects by focusing the electric field towards the detectors' central axes. Four detectors were fabricated with the new hybrid anode contact, and their performances were evaluated and compared to those from the previous design for our virtual Frisch-grid detectors. The results obtained for all four showed similar improvement: therefore, we illustrate them with the findings from one detector.

  3. CZT Virtual Frisch-grid Detector: Principles and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Cui,Y.; Bolotnikov, A.; Camarda, G.; Hossain, A.; James, R. B.

    2009-03-24

    Cadmium Zinc Telluride (CdZnTe or CZT) is a very attractive material for using as room-temperature semiconductor detectors, because it has a wide bandgap and a high atomic number. However, due to the material's poor hole mobility, several special techniques were developed to ensure its suitability for radiation detection. Among them, the virtual Frisch-grid CZT detector is an attractive option, having a simple configuration, yet delivering an outstanding spectral performance. The goal of our group in Brookhaven National Laboratory (BNL) is to improve the performance of Frisch-ring CZT detectors; most recently, that effort focused on the non-contacting Frisch-ring detector, allowing us to build an inexpensive, large-volume detector array with high energy-resolution and a large effective area. In this paper, the principles of virtual Frisch-grid detectors are described, especially BNL's innovative improvements. The potential applications of virtual Frisch-grid detectors are discussed, and as an example, a hand-held gamma-ray spectrometer using a CZT virtual Frischgrid detector array is introduced, which is a self-contained device with a radiation detector, readout circuit, communication circuit, and high-voltage supply. It has good energy resolution of 1.4% (FWHM of 662-keV peak) with a total detection volume of {approx}20 cm{sup 3}. Such a portable inexpensive device can be used widely in nonproliferation applications, non-destructive detection, radiation imaging, and for homeland security. Extended systems based on the same technology have potential applications in industrial- and nuclear-medical-imaging.

  4. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, A. E., E-mail: bolotnik@bnl.gov; Ackley, K.; Camarda, G. S.; Cherches, C.; Cui, Y.; De Geronimo, G.; Fried, J.; Hossain, A.; Mahler, G.; Maritato, M.; Roy, U.; Salwen, C.; Vernon, E.; Yang, G.; James, R. B. [Brookhaven National Laboratory, Upton, New York 11793 (United States); Hodges, D. [University of Texas at El Paso, El Paso, Texas 79968 (United States); Lee, W. [Korea University, Seoul 136-855 (Korea, Republic of); Petryk, M. [SUNY Binghamton, Vestal, New York 13902 (United States)

    2015-07-15

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm{sup 3} detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays’ performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

  5. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras.

    Science.gov (United States)

    Bolotnikov, A E; Ackley, K; Camarda, G S; Cherches, C; Cui, Y; De Geronimo, G; Fried, J; Hodges, D; Hossain, A; Lee, W; Mahler, G; Maritato, M; Petryk, M; Roy, U; Salwen, C; Vernon, E; Yang, G; James, R B

    2015-07-01

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm(3) detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays' performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

  6. Array of virtual Frisch-grid CZT detectors with common cathode readout and pulse-height correction

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Egarievwe, E.U.; Fochuk, P.M.; Fuerstnau, M.; Gul, R.; Hossain, A.; Jones, F.; Kim, K.; Kopach, O.V.; Taggart, R.; Yang, G.; Ye, Z.; Xu, L.; and James, R.B.

    2010-08-01

    We present our new results from testing 15-mm-long virtual Frisch-grid CdZnTe detectors with a common-cathode readout for correcting pulse-height distortions. The array employs parallelepiped-shaped CdZnTe (CZT) detectors of a large geometrical aspect ratio, with two planar contacts on the top and bottom surfaces (anode and cathode) and an additional shielding electrode on the crystal's sides to create the virtual Frisch-grid effect. We optimized the geometry of the device and improved its spectral response. We found that reducing to 5 mm the length of the shielding electrode placed next to the anode had no adverse effects on the device's performance. At the same time, this allowed corrections for electron loss by reading the cathode signals to obtain depth information.

  7. Characterization of Cd{sub 0.9}Zn{sub 0.1}Te based virtual Frisch grid detectors for high energy gamma ray detection

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, R.M.; Chaudhuri, S.K.; Zavalla, K.J. [Department of Electrical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Mandal, K.C., E-mail: mandalk@cec.sc.edu [Department of Electrical Engineering, University of South Carolina, Columbia, SC 29208 (United States)

    2013-02-11

    Detector grade CZT single crystals have been grown from zone refined Cd, Zn, and Te (∼7 N) precursor materials using a tellurium solvent method. Infrared transmission imaging has shown an average tellurium inclusion size of ∼8 μm in the as-grown crystal. Radiation detectors were fabricated in planar and virtual Frisch grid geometry and characterized for their spectroscopic performance. Charge transport properties revealed a high drift mobility of∼1200 cm{sup 2}/V s and a mobility–lifetime product of ∼2.8×10{sup −3} cm{sup 2}/V. A detector with planar configuration (dimensions 6.9×6.9×4.8 mm{sup 3}) showed an energy resolution of 4.7% for 59.5 keV gamma rays. The detector in a Frisch grid configuration (dimensions 4.2×6.2×6.5 mm{sup 3}) exhibited an energy resolution of 1.4% for 662 keV gamma rays. Digital spectroscopic measurements were carried out using a high-resolution digitizer card. A biparametric correlation scheme was employed to study the effect of charge loss on energy resolution of the planar detector. Based on this correlation scheme, a digital correction method was applied and improved pulse-height spectrum was obtained for 662 keV gamma rays using the planar detector with spectral features comparable to those of the virtual Frisch grid detector.

  8. Enhanced R200 with Frisch-Grid CZT

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-02-01

    Current technology using hand-held NaI scintillators with poor energy resolution can be greatly improved upon by using Virtual Frisch Grid-CZT detectors. The CZT semiconductor detectors will provide more reliable isotope identification and more precise measurement of photopeak areas in the presence of strong Compton background. The Virtual Frisch Grid design allows for correction of charge losses that occur at defects with much less expensive industrial grade crystals.

  9. Novel electrode geometry to improve performance of CdZnTe detectors

    DEFF Research Database (Denmark)

    van Pamelen, M.A.J.; Budtz-Jørgensen, Carl

    1998-01-01

    unipolar sensing. The effectiveness of the geometry was demonstrated with a CdZnTe crystal. Above X-ray energies of 40 keV, large improvements were achieved ill the spectral sensitivity, and the spectral resolution could be increased further by applying a correction for charge trapping. The peak of Cs-137......A novel electrode geometry to improve the sensitivity to single-polarity charge carriers in ionization detectors is presented. The electrode geometry is based on the same principle as Frisch grids in gas detectors. It reduces the sensitivity to one type of charge carrier, making the detector almost...

  10. High-Efficiency CdZnTe Position-Sensitive VFG Gamma-Ray Detectors for Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey E. [Brookhaven National Lab. (BNL), Upton, NY (United States); James, Ralph B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); De Geronimo, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Vernon, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Camarda, G. S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hossain, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Indusi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Boyer, Brian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-30

    The goal of this project is to incorporate a Cadmium-Zinc-Telluride (CdZnTe or CZT) detector (with 1% or better resolution) into a bench-top prototype for isotope identification and related safeguards applications. The bench-top system is based on a 2x2 array of 6x6x20 mm3 position-sensitive virtual Frisch-grid (VFG) CZT detectors. The key features of the array are that it allows for the use of average-grade CZT material with a moderate content of defects, and yet it provides high energy resolution, 1% FWHM at 662 keV, large effective area, and low-power consumption. The development of this type of 3D detector and new instruments incorporating them is motivated by the high cost and low availability of large, > 1 cm3, CZT crystals suitable for making multi-pixel detectors with acceptable energy resolution and efficiency.

  11. High-Efficiency CdZnTe Position-Sensitive VFG Gamma-Ray Detectors for Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey E. [Brookhaven National Lab. (BNL), Upton, NY (United States); James, Ralph B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); De Geronimo, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Vernon, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Camarda, G. S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hossain, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Indusi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Boyer, Brian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-30

    The goal of this project is to incorporate a Cadmium-Zinc-Telluride (CdZnTe or CZT) detector (with 1% or better resolution) into a bench-top prototype for isotope identification and related safeguards applications. The bench-top system is based on a 2x2 array of 6x6x20 mm3 position-sensitive virtual Frisch-grid (VFG) CZT detectors. The key features of the array are that it allows for the use of average-grade CZT material with a moderate content of defects, and yet it provides high-energy resolution, 1% FWHM at 662 keV, large effective area, and low-power consumption. The development of this type of 3D detector and new instruments incorporating them is motivated by the high cost and low availability of large, > 1 cm3, CZT crystals suitable for making multi-pixel detectors with acceptable energy resolution and efficiency.

  12. Pixelated CdZnTe drift detectors

    DEFF Research Database (Denmark)

    Kuvvetli, Irfan; Budtz-Jørgensen, Carl

    2005-01-01

    A technique, the so-called Drift Strip Method (DSM), for improving the CdZnTe detector energy response to hard X-rays and gamma-rays was applied as a pixel geometry. First tests have confirmed that this detector type provides excellent energy resolution and imaging performance. We specifically...... report on the performance of 3 mm thick prototype CZT drift pixel detectors fabricated using material from eV-products. We discuss issues associated with detector module performance. Characterization results obtained from several prototype drift pixel detectors are presented. Results of position...

  13. PERFORMANCE STUDIES OF CDZNTE DETECTOR BY USING A PULSE SHAPE ANALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    BOLOTNIKOV, A.

    2005-07-31

    Pulse shape analysis is proved to be a powerful tool to characterize the performance of CdZnTe devices and understand their operating principles. It allows one to investigate the device configurations, electron transport properties, effects governing charge collection, electric-field distributions, signal charge formation, etc. This work describes an application of different techniques based on the pulse shape measurements to characterize pixel, coplanar-grid, and virtual Frisch-grid devices and understand the electronic properties of CZT material provided by different vendors. We report new results that may explain the performance limits of these devices.

  14. Al-doped ZnO contact to CdZnTe for x- and gamma-ray detector applications

    Science.gov (United States)

    Roy, U. N.; Camarda, G. S.; Cui, Y.; Gul, R.; Hossain, A.; Yang, G.; Mundle, R. M.; Pradhan, A. K.; James, R. B.

    2016-06-01

    The poor adhesion of common metals to CdZnTe (CZT)/CdTe surfaces has been a long-standing challenge for radiation detector applications. In this present work, we explored the use of an alternative electrode, viz., Al-doped ZnO (AZO) as a replacement to common metallic contacts. ZnO offers several advantages over the latter, such as having a higher hardness, a close match of the coefficients of thermal expansion for CZT and ZnO, and better adhesion to the surface of CZT due to the contact layer being an oxide. The AZO/CZT contact was investigated via high spatial-resolution X-ray response mapping for a planar detector at the micron level. The durability of the device was investigated by acquiring I-V measurements over an 18-month period, and good long-term stability was observed. We have demonstrated that the AZO/CZT/AZO virtual-Frisch-grid device performs fairly well, with comparable or better characteristics than that for the same detector fabricated with gold contacts.

  15. On the Frisch-Grid signal in ionization chambers

    Energy Technology Data Exchange (ETDEWEB)

    Al-Adili, A. [EC-JRC - Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Division of Applied Nuclear Physics, Uppsala University, S-751 20 Uppsala (Sweden); Hambsch, F.-J., E-mail: Franz-Josef.HAMBSCH@ec.europa.eu [EC-JRC - Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Bencardino, R. [EC-JRC - Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Pomp, S. [Division of Applied Nuclear Physics, Uppsala University, S-751 20 Uppsala (Sweden); Oberstedt, S. [EC-JRC - Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Zeynalov, Sh. [JINR - Joint Institute for Nuclear Research, Dubna, R-141980 (Russian Federation)

    2012-04-11

    A recent theoretical approach concerning the grid-inefficiency (GI) problem in Twin Frisch-Grid Ionization Chambers was validated experimentally. The experimental verification focused on the induced signal on the anode plate. In this work the investigation was extended by studying the grid signal. The aim was to verify the grid-signal dependency on the grid inefficiency {sigma}. The measurements were made with fission fragments from {sup 252}Cf(sf), using two different grids, with 1 and 2 mm wire distances, leading to the GI values: {sigma}=0.031 and {sigma}=0.083, respectively. The theoretical grid signal was confirmed because the detected grid pulse-height distribution was smaller for the larger {sigma}. By applying the additive GI correction approach, the two grid pulse heights were consistent. In the second part of the work, the corrected grid signal was used to deduce emission angles of the fission fragments. It is inconvenient to treat the grid signal by means of conventional analogue electronics, because of its bipolarity. Therefore, the anode and grid signals were summed to create a unipolar, angle-dependent pulse height. Until now the so-called summing method has been the well-established approach to deduce the angle from the grid signal. However, this operation relies strongly on an accurate and stable calibration between the two summed signals. By application of digital-signal processing, the grid signal's bipolarity is no longer an issue. Hence one can bypass the intermediate summation step of the two different pre-amplifier signals, which leads to higher stability. In this work the grid approach was compared to the summing method in three cases: {sup 252}Cf(sf), {sup 235}U(n,f) and {sup 234}U(n,f). By using the grid directly, the angular resolution was found equally good in the first case but gave 7% and 20% improvements, respectively, in the latter cases.

  16. Upgrading FLIR NanoRaider with the next Generation of CdZnTe Detectors. Goal - Integrate VFG detectors into FLIR R200. Advanced Virtual Grid ASIC (AVG-ASIC).

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Yonggang [Brookhaven National Lab. (BNL), Upton, NY (United States); Vernon, Emerson [Brookhaven National Lab. (BNL), Upton, NY (United States); De Geronimo, Gianluigi [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-06-01

    This document presents motivations, goals and the current status of this project; development (fabrication, performance) of position-sensitive virtual Frisch-grid detectors proposed for nanoRaider, an instrument commonly used by nuclear inspectors; ASIC developments for CZT detectors; and the electronics development for the detector prototype..

  17. Use of high-granularity CdZnTe pixelated detectors to correct response non-uniformities caused by defects in crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, A.E., E-mail: bolotnik@bnl.gov [Brookhaven National Laboratory, Upton, NY 11793 (United States); Camarda, G.S.; Cui, Y.; De Geronimo, G. [Brookhaven National Laboratory, Upton, NY 11793 (United States); Eger, J.; Emerick, A. [eV Products Inc., Saxonburg, PA 16056 (United States); Fried, J.; Hossain, A.; Roy, U.; Salwen, C. [Brookhaven National Laboratory, Upton, NY 11793 (United States); Soldner, S. [eV Products Inc., Saxonburg, PA 16056 (United States); Vernon, E.; Yang, G.; James, R.B. [Brookhaven National Laboratory, Upton, NY 11793 (United States)

    2016-01-01

    Following our successful demonstration of the position-sensitive virtual Frisch-grid detectors, we investigated the feasibility of using high-granularity position sensing to correct response non-uniformities caused by the crystal defects in CdZnTe (CZT) pixelated detectors. The development of high-granularity detectors able to correct response non-uniformities on a scale comparable to the size of electron clouds opens the opportunity of using unselected off-the-shelf CZT material, whilst still assuring high spectral resolution for the majority of the detectors fabricated from an ingot. Here, we present the results from testing 3D position-sensitive 15×15×10 mm{sup 3} pixelated detectors, fabricated with conventional pixel patterns with progressively smaller pixel sizes: 1.4, 0.8, and 0.5 mm. We employed the readout system based on the H3D front-end multi-channel ASIC developed by BNL's Instrumentation Division in collaboration with the University of Michigan. We use the sharing of electron clouds among several adjacent pixels to measure locations of interaction points with sub-pixel resolution. By using the detectors with small-pixel sizes and a high probability of the charge-sharing events, we were able to improve their spectral resolutions in comparison to the baseline levels, measured for the 1.4-mm pixel size detectors with small fractions of charge-sharing events. These results demonstrate that further enhancement of the performance of CZT pixelated detectors and reduction of costs are possible by using high spatial-resolution position information of interaction points to correct the small-scale response non-uniformities caused by crystal defects present in most devices. - Highlights: • We investigated performances of 3D position sensitive CdZnTe pixelated detectors. • We employed the readout electronics based on H3D ASIC and data processing. • We demonstrated the feasibility of correcting response nonuniformities in CdZnTe pixelated detectors.

  18. Use of high-granularity CdZnTe pixelated detectors to correct response non-uniformities caused by defects in crystals

    Science.gov (United States)

    Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; De Geronimo, G.; Eger, J.; Emerick, A.; Fried, J.; Hossain, A.; Roy, U.; Salwen, C.; Soldner, S.; Vernon, E.; Yang, G.; James, R. B.

    2016-01-01

    Following our successful demonstration of the position-sensitive virtual Frisch-grid detectors, we investigated the feasibility of using high-granularity position sensing to correct response non-uniformities caused by the crystal defects in CdZnTe (CZT) pixelated detectors. The development of high-granularity detectors able to correct response non-uniformities on a scale comparable to the size of electron clouds opens the opportunity of using unselected off-the-shelf CZT material, whilst still assuring high spectral resolution for the majority of the detectors fabricated from an ingot. Here, we present the results from testing 3D position-sensitive 15×15×10 mm3 pixelated detectors, fabricated with conventional pixel patterns with progressively smaller pixel sizes: 1.4, 0.8, and 0.5 mm. We employed the readout system based on the H3D front-end multi-channel ASIC developed by BNL's Instrumentation Division in collaboration with the University of Michigan. We use the sharing of electron clouds among several adjacent pixels to measure locations of interaction points with sub-pixel resolution. By using the detectors with small-pixel sizes and a high probability of the charge-sharing events, we were able to improve their spectral resolutions in comparison to the baseline levels, measured for the 1.4-mm pixel size detectors with small fractions of charge-sharing events. These results demonstrate that further enhancement of the performance of CZT pixelated detectors and reduction of costs are possible by using high spatial-resolution position information of interaction points to correct the small-scale response non-uniformities caused by crystal defects present in most devices.

  19. High-resolution ionization detector and array of such detectors

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas S. (Ypsilanti, MI); Rojeski, Ronald A. (Pleasanton, CA)

    2001-01-16

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

  20. Characteristics of a prototype CdZnTe detector

    Institute of Scientific and Technical Information of China (English)

    XU Huichao; CHENG Cheng; ZHAO Cuilan; ZHANG Jinzhou; PU Shijie

    2007-01-01

    Cadmium zinc telluride(CZT)is a preferred material for X-ray and gamma-ray detector.Thanks to the relatively high atomic number,high density and wide band-gap.CZT detector possesses sharp energy resolution and high detection efficiency without cryogenic cooling.We have developed a CdZnTe detector with an energy resolution of 3.45%(FWHM)at 59.54 keV at room temperature.and it is used for X-ray fluorescence analysis.In this paper,leakage current,energy resolution and long term stability of the CZT detector are discussed.

  1. Leakage current measurements on pixelated CdZnTe detectors

    NARCIS (Netherlands)

    Dirks, B.P.F.; Blondel, C.; Daly, F.; Gevin, O.; Limousin, O.; Lugiez, F.

    2006-01-01

    In the field of the R&D of a new generation hard X-ray cameras for space applications we focus on the use of pixelated CdTe or CdZnTe semiconductor detectors. They are covered with 64 (0.9×0.9 mm2) or 256 (0.5×0.5 mm2) pixels, surrounded by a guard ring and operate in the energy ranging from several

  2. NEW RESULTS FROM TESTING OF COPLANAR-GRID CDZNTE DETECTOR.

    Energy Technology Data Exchange (ETDEWEB)

    CARINI, G.A.; ET AL.

    2005-07-31

    New results from studies of coplanar-grid CdZnTe (CZT) detectors are presented. The coplanar-grid detectors, were investigated by using a highly collimated X-ray beam available at Brookhaven's National Synchrotron Light Source and by applying a pulse-shape analysis. The coplanar-grid detector operates as a single-carrier device. Despite the fact that its operational principle is well known and has been investigated by many groups in the past, we found some new details that may explain the performance limits of these types of devices. The experimental results have been confirmed by extensive computer modeling.

  3. Development of Portable Uranium Enrichment Measurement Apparatus With CdZnTe Detector

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>A portable uranium enrichment measurement apparatus with CdZnTe detector manufactured by "eV Products" company was tested in this work. The apparatus consists of a co-planar grid detector based on

  4. READOUT SYSTEM FOR ARRAYS OF FRISCH-RING CDZNTE DETECTORS.

    Energy Technology Data Exchange (ETDEWEB)

    CUI, Y.; BOLOTNIKOV, A.E.; CAMARDA, G.S.; DE GERONIMO, G.; O' CONNOR, P.; JAMES, R.B.; KARGAR, A.; HARRISON, M.J.; MCGREGOR, D.S.

    2006-10-29

    Frisch-ring CdZnTe detectors have demonstrated good energy resolution for identifying isotopes, <1% FWHM at 662 keV, and good efficiency for detecting gamma rays. We will fabricate and test at Brookhaven National Laboratory an integrated module of a 64-element array of 6 x 6 x 12 mm{sup 3} Frisch-ring detectors, coupled with a readout electronics system. It supports 64 readout channels, and includes front-end electronics, signal processing circuit, USB interface and high-voltage power supply. The data-acquisition software is used to process the data stream, which includes amplitude and timing information for each detected event. This paper describes the design and assembly of the detector modules, readout electronics, and a conceptual prototype system. Some test results are also reported.

  5. Performance updating of CdZnTe strip-drift detectors

    DEFF Research Database (Denmark)

    Shorohov, M.; Tsirkunova, I.; Loupilov, A.;

    2007-01-01

    59.6 and 662 keV correspondingly. Recently, significant progress was done in CdZnTe crystals growth technology. In the present paper we present preliminary result of performance updating of CdZnTe strip-drift detectors based on crystal of 10 x 10 x 6 mm 3 produced by Yinnel Tech company. Results...

  6. Prototype imaging Cd-Zn-Te array detector

    Energy Technology Data Exchange (ETDEWEB)

    Bloser, P.F.; Narita, T.; Grindlay, J.E. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Shah, K. [Radiation Monitoring Devices, Inc., Watertown, MA (United States)

    1998-12-31

    The authors describe initial results of their program to develop and test Cd-Zn-Te (CZT) detectors with a pixellated array readout. Their primary interest is in the development of relatively thick CZT detectors for use in astrophysical coded aperture telescopes with response extending over the energy range {approximately}10--600 keV. The coded aperture imaging configuration requires only relatively large area pixels (1--3 mm), whereas the desired high energy response requires detector thicknesses of at least 3--5 mm. They have developed a prototype detector employing a 10 x 10 x 5 mm CZT substrate and 4 x 4 pixel (1.5 mm each) readout with gold metal contacts for the pixels and continuous gold contact for the bias on the opposite detector face. This MSM contact configuration was fabricated by RMD and tested at Harvard for uniformity, efficiency and spatial as well as spectral resolution. The authors have developed an ASIC readout (IDE-VA-1) and analysis system and report results, including {approximately}4% (FWHM) energy resolution at 60 keV. A prototype design for a full imaging detector array is discussed.

  7. Prototype Imaging Cd-Zn-Te Array Detector

    CERN Document Server

    Bloser, P F; Grindlay, J E; Shah, K

    1998-01-01

    We describe initial results of our program to develop and test Cd-Zn-Te (CZT) detectors with a pixellated array readout. Our primary interest is in the development of relatively thick CZT detectors for use in astrophysical coded aperture telescopes with response extending over the energy range $\\sim 10-600$ keV. The coded aperture imaging configuration requires only relatively large area pixels (1-3 mm), whereas the desired high energy response requires detector thicknesses of at least 3-5 mm. We have developed a prototype detector employing a 10 x 10 x 5 mm CZT substrate and 4 x 4 pixel (1.5 mm each) readout with gold metal contacts for the pixels and continuous gold contact for the bias on the opposite detector face. This MSM contact configuration was fabricated by RMD and tested at Harvard for uniformity, efficiency and spatial as well as spectral resolution. We have developed an ASIC readout (IDE-VA-1) and analysis system and report results, including $\\sim 4$% (FWHM) energy resolution at 60 keV. A protot...

  8. A highly pixelated CdZnTe detector based on \\textit{Topmetal-${II}^-$} sensor

    CERN Document Server

    Zou, Shuguang; Sun, Xiangming; Huang, Guangming; Pei, Hua; Wang, Zhen; Liu, Jun; Yang, Ping; Wang, Dong

    2016-01-01

    \\textit{Topmetal-${II}^-$} is a low noise CMOS pixel direct charge sensor with a pitch of 83$\\mu m$. CdZnTe is an excellent semiconductor material for radiation detection. The combination of CdZnTe and the sensor makes it possible to build a detector with high spatial resolution. In our experiments, an epoxy adhesive is used as the conductive medium to connect the sensor and CdZnTe. The diffusion coefficient and charge efficiency of electrons are measured at a low bias voltage of -2 Volts, and the image of a single alpha is clear with a reasonable spatial resolution. The detector of such structure has the potential to be applied in X-ray imaging systems with a further improvements of the sensor.

  9. A method for measuring the electron drift velocity in working gas using a Frisch-grid ionization chamber

    Science.gov (United States)

    Bai, Huaiyong; Wang, Zhimin; Zhang, Luyu; Chen, Jinxiang; Zhang, Guohui

    2016-12-01

    A method for measuring the electron drift velocity in working gas is proposed. Based on the cathode and the anode signal waveforms of the Frisch-grid ionization chamber, the electron drift velocity is extracted. With this method, the electron drift velocities in Ar + 10% CH4, Ar + 3.5% CO2 and Kr + 2.7% CO2 gases have been measured and the results are compared with the existing measurements and the simulating results. Using this method, the electron drift velocity can be monitored throughout the experiment of charged particle without bothering the measurement of other parameters, such as the energy and orientation.

  10. The analysis of X-ray response of CdZnTe detectors

    Institute of Scientific and Technical Information of China (English)

    ZHA GangQiang; XIANG Hang; LIU Ting; XU YaDong; WANG Tao; JIE WanQi

    2012-01-01

    CdZnTe is an excellent material candidate for high efficiency,high-resolution room-temperature nuclear radiation detectors,and the CdZnTe detectors are being widely used in medicine,industry,safeguard and scientific X-ray and γ-ray imaging and spectroscopic applications.In this work,three CdZnTe planar detectors with different grades,named CZT-1,CZT-2 and CZT-3,respectively,were fabricated.And the effects of mobility,lifetime and de-trapping time on the performance of CdZnTe planar detector,such as the energy rcsolution,charge collection efficiency and peak to valley ratio,were analyzed.The charge collection efficiency depends on the product of carrier mobility and lifetime,which has a great effect on the energy resolution of detector when the efficiency is less than 90%.The de-trapping time of carriers in deep levels should be responsible for the peak to valley ratio and "polarization".

  11. High performance p-i-n CdTe and CdZnTe detectors

    CERN Document Server

    Khusainov, A K; Ilves, A G; Morozov, V F; Pustovoit, A K; Arlt, R D

    1999-01-01

    A breakthrough in the performance of p-i-n CdTe and CdZnTe detectors is reported. The detector stability has been significantly improved, allowing their use in precise gamma and XRF applications. Detectors with energy resolution close to Si and Ge were produced operating with only -30--35 deg. C cooling (by a Peltier cooler of 15x15x10 mm size and a consumed power less than 5 W). Presently detectors with volume of up to 300 mm sup 3 are available. In terms of photoelectric effect efficiency it corresponds to HPGe detectors with volumes of about 1.5 cm sup 3. The possibilities of further improvement of CdTe and CdZnTe detector characteristics are discussed in this paper.

  12. Hard x-ray response of pixellated CdZnTe detectors

    Science.gov (United States)

    Abbene, L.; Del Sordo, S.; Caroli, E.; Gerardi, G.; Raso, G.; Caccia, S.; Bertuccio, G.

    2009-06-01

    In recent years, the development of cadmium zinc telluride (CdZnTe) detectors for x-ray and gamma ray spectrometry has grown rapidly. The good room temperature performance and the high spatial resolution of pixellated CdZnTe detectors make them very attractive in space-borne x-ray astronomy, mainly as focal plane detectors for the new generation of hard x-ray focusing telescopes. In this work, we investigated on the spectroscopic performance of two pixellated CdZnTe detectors coupled with a custom low noise and low power readout application specific integrated circuit (ASIC). The detectors (10×10×1 and 10×10×2 mm3 single crystals) have an anode layout based on an array of 256 pixels with a geometric pitch of 0.5 mm. The ASIC, fabricated in 0.8 μm BiCMOS technology, is equipped with eight independent channels (preamplifier and shaper) and characterized by low power consumption (0.5 mW/channel) and low noise (150-500 electrons rms). The spectroscopic results point out the good energy resolution of both detectors at room temperature [5.8% full width at half maximum (FWHM) at 59.5 keV for the 1 mm thick detector; 5.5% FWHM at 59.5 keV for the 2 mm thick detector) and low tailing in the measured spectra, confirming the single charge carrier sensing properties of the CdZnTe detectors equipped with a pixellated anode layout. Temperature measurements show optimum performance of the system (detector and electronics) at T =10 °C and performance degradation at lower temperatures. The detectors and the ASIC were developed by our collaboration as two small focal plane detector prototypes for hard x-ray multilayer telescopes operating in the 20-70 keV energy range.

  13. The development of drift-strip detectors based on CdZnTe

    DEFF Research Database (Denmark)

    Gostilo, V.; Budtz-Jørgensen, Carl; Kuvvetli, Irfan

    2002-01-01

    The design and technological development of a CdZnTe drift strip detector is described. The device is based on a monocrystal of dimensions 10 x 10 x 3 mm(3) and has a pitch of 200 mum and a strip width of 100 mum. The strip length is 9.5 mm. The distribution of the leakage currents of the strips...

  14. Nuclear reactor pulse calibration using a CdZnTe electro-optic radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: knelson1@ksu.edu [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Geuther, Jeffrey A. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Neihart, James L.; Riedel, Todd A. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Rojeski, Ronald A. [Nanometrics, Inc., 1550 Buckeye Drive, Milpitas, CA 95035 (United States); Saddler, Jeffrey L. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Schmidt, Aaron J.; McGregor, Douglas S. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2012-07-15

    A CdZnTe electro-optic radiation detector was used to calibrate nuclear reactor pulses. The standard configuration of the Pockels cell has collimated light passing through an optically transparent CdZnTe crystal located between crossed polarizers. The transmitted light was focused onto an IR sensitive photodiode. Calibrations of reactor pulses were performed using the CdZnTe Pockels cell by measuring the change in the photodiode current, repeated 10 times for each set of reactor pulses, set between 1.00 and 2.50 dollars in 0.50 increments of reactivity. - Highlights: Black-Right-Pointing-Pointer We demonstrated the first use of an electro-optic device to trace reactor pulses in real-time. Black-Right-Pointing-Pointer We examined the changes in photodiode current for different reactivity insertions. Black-Right-Pointing-Pointer Created a linear best fit line from the data set to predict peak pulse powers.

  15. The Effect of Twin Boundaries on the Spectroscopic Performance of CdZnTe Detectors

    Science.gov (United States)

    Parker, Bradford H.; Stahle, C. M.; Roth, D.; Babu, S.; Tueller, Jack; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Most single grains in cadmium zinc telluride (CdZnTe) grown by the high-pressure Bridgman (HPB) technique contain multiple twin boundaries. As a consequence, twin boundaries are one of the most common macroscopic material defects found in large area (400 to 700 sq mm) CdZnTe specimens obtained from HPB ingots. Due to the prevalence of twin boundaries, understanding their effect on detector performance is key to the material selection process. Twin boundaries in several 2 mm thick large area specimens were first, documented using infrared transmission imaging. These specimens were then fabricated into either 2 mm pixel or planar detectors in order to examine the effect of the twin boundaries on detector performance. Preliminary results show that twin boundaries, which are decorated with tellurium inclusions, produce a reduction in detector efficiency and a degradation in resolution. The extent of the degradation appears to be a function of the density of tellurium inclusions.

  16. Charge-sensitive front-end electronics with operational amplifiers for CdZnTe detectors

    OpenAIRE

    Födisch, P.; Berthel, M.; Lange, B; Kirschke, T.; Enghardt, W.; Kaever, P.

    2016-01-01

    Cadmium zinc telluride (CdZnTe, CZT) radiation detectors are suitable for a variety of applications, due to their high spatial resolution and spectroscopic energy performance at room temperature. However, state-of-the-art detector systems require high-performance readout electronics. Though an application-specific integrated circuit (ASIC) is an adequate solution for the readout, requirements of high dynamic range and high throughput are not available in any commercial circuit. Consequently, ...

  17. A single CdZnTe detector for simultaneous CT/SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Barber, W.C. E-mail: bill@barber.uscf.edu; Iwata, Koji; Hasegawa, B.H.; Bennett, P.R.; Cirignano, L.J.; Shah, K.S

    2003-06-01

    Clinical CT/SPECT systems acquire CT and SPECT data sequentially using different detectors in close proximity to minimise patient movement and interscan delay. We have developed a prototype simultaneous CT/SPECT imager, using a single CdZnTe detector, with the goal of improving image coregistration and decreasing scan time. A 16-pixel CdZnTe detector was operated in pulse-counting mode with 50 ns shaping time. Energy discrimination is used to separate the CT and SPECT data. Simultaneous SPECT and CT images were obtained for a phantom with the X-ray flux limited to reduce pulse pile-up in the radionuclide energy window. At 140 keV, the efficiency and energy resolution are 70% and 10%, respectively, and were constant for fluence rates up to 10{sup 3} cps per detector element for 140 keV gamma rays, but degrade rapidly at higher fluence rates. In pulse-counting mode, the maximum count rate of 10{sup 3} cps per element from the CdZnTe detector is sufficient for SPECT imaging, but is considerably lower than the fluence rates encountered in CT. The smallest lesion visually detectable in SPECT is 9 mm and the CT spatial resolution is smaller than 4.5 mm. Image registration is intrinsic because the data can be acquired simultaneously with a single detector with the same reconstruction geometry.

  18. Characterization of a large CdZnTe coplanar quad-grid semiconductor detector

    CERN Document Server

    Ebert, Joachim; Gehre, Daniel; Hagner, Caren; Heidrich, Nadine; Klingenberg, Rainer; Kröninger, Kevin; Nitsch, Christian; Oldorf, Christian; Quante, Thomas; Rajek, Silke; Rebber, Henning; Rohatsch, Katja; Tebrügge, Jan; Temminghoff, Robert; Theinert, Robert; Timm, Jan; Wonsak, Björn; Zatschler, Stefan; Zuber, Kai

    2015-01-01

    The COBRA collaboration aims to search for neutrinoless double beta-decay of $^{116}$Cd. A demonstrator setup with 64 CdZnTe semiconductor detectors, each with a volume of 1cm$^3$, is currently being operated at the LNGS underground laboratory in Italy. This paper reports on the characterization of a large (2 $\\times$ 2 $\\times$ 1.5)cm$^3$ CdZnTe detector with a new coplanar-grid design for applications in $\\gamma$-ray spectroscopy and low-background operation. Several studies of electric properties as well as of the spectrometric performance, like energy response and resolution, are conducted. Furthermore, measurements including investigating the operational stability and a possibility to identify multiple-scattered photons are presented.

  19. Correction of diagnostic x-ray spectra measured with CdTe and CdZnTe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, M. [Osaka Univ., Suita (Japan). Medical School; Kanamori, H.; Toragaito, T.; Taniguchi, A.

    1996-07-01

    We modified the formula of stripping procedure presented by E. Di. Castor et al. We added the Compton scattering and separated K{sub {alpha}} radiation of Cd and Te (23 and 27keV, respectively). Using the new stripping procedure diagnostic x-ray spectra (object 4mm-Al) of tube voltage 50kV to 100kV for CdTe and CdZnTe detectors are corrected with comparison of those spectra for the Ge detector. The corrected spectra for CdTe and CdZnTe detectors coincide with those for Ge detector at lower tube voltage than 70kV. But the corrected spectra at higher tube voltage than 70kV do not coincide with those for Ge detector. The reason is incomplete correction for full energy peak efficiencies of real CdTe and CdZnTe detectors. (J.P.N.)

  20. CdZnTe position-sensitive drift detectors with thicknesses up to 5 cm

    Science.gov (United States)

    Bolotnikov, A. E.; Camarda, G. S.; Chen, E.; Cheng, S.; Cui, Y.; Gul, R.; Gallagher, R.; Dedic, V.; De Geronimo, G.; Ocampo Giraldo, L.; Fried, J.; Hossain, A.; MacKenzie, J. M.; Sellin, P.; Taherion, S.; Vernon, E.; Yang, G.; El-hanany, U.; James, R. B.

    2016-02-01

    We investigated the feasibility of long-drift-time CdZnTe (CZT) gamma-ray detectors, fabricated from CZT material produced by Redlen Technologies. CZT crystals with cross-section areas of 5 × 5 mm2 and 6 × 6 mm2 and thicknesses of 20-, 30-, 40-, and 50-mm were configured as 3D position-sensitive drift detectors and were read out using a front-end ASIC. By correcting the electron charge losses caused by defects in the crystals, we demonstrated high performance for relatively thick detectors fabricated from unselected CZT material.

  1. CdZnTe position-sensitive drift detectors with thicknesses up to 5 cm

    OpenAIRE

    Bolotnikov, AE; Camarda, GS; Chen, E.; Cheng, S.; Cui, Y.; Gul, R; Gallagher, R; Dedic, V.; De Geronimo, G.; Giraldo, LO; Fried, J.; Hossain, A; MacKenzie, JM; Sellin, P.; Taherion, S

    2016-01-01

    We investigated the feasibility of long-drift-time CdZnTe (CZT) gamma-ray detectors, fabricated from CZT material produced by Redlen Technologies. CZT crystals with cross-section areas of 5 5 mm2 and 6 6 mm2 and thicknesses of 20-, 30-, 40-, and 50-mm were configured as 3D position-sensitive drift detectors and were read out using a front-end ASIC. By correcting the electron charge losses caused by defects in the crystals, we demonstrated high performance for relatively thick detectors fabric...

  2. Research of CdZnTe detector based portable energy dispersive spectrometer

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A kind of excellent CdZnTe crystal has been grown in Yinnel Tech, Inc. in recent years. Based on these CdZnTe crystals and some new techniques, a portable energy-dispersive spectrometer has been constructed which has yielded good results. CdZnTe detector has a 3% relative resolution in high-energy field and can detect gamma rays at room temperature. An integrated circuit based on preamplifier and shaping amplifier chips is connected to the detector.Voltage pulses are transformed into digital signals in MCA (multichannel analyzer) and are then transmitted to computer via USB bus. Data process algorithms are improved in this spectrometer. Fast Fourier transform (FFT) and numerical differentiation (ND) are used in energy peak's searching program. Sampling-based correction technique is used in X-ray energy calibration. Modified Gaussian-Newton algorithm is a classical method to solve nonlinear curve fitting problems, and it is used to compute absolute intensity of each detected characteristic line.

  3. A test device for isotopic γ-ray imaging with CdZnTe detector

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A test device for isotopic γ-ray imaging, which consists of an isotope γ-ray source, a CdZnTe γ-ray spectrometer and other auxiliary equipment, is studied here. Compared with the conventional X-ray, the isotope γ-ray,which is utilized in this project, has its own advantages in imaging. Furthermore, with a room-temperature high-energy-resolution CdZnTe detector and a modern imaging processing technique, this device is capable of effectively suppressing the background and gaining more information, thus it can obtain a better image than conventional X-ray devices. In the experiment of PCB imaging, all soldered points and chip components are sharply demonstrated.

  4. Charge-Sensitive Front-End Electronics with Operational Amplifiers for CdZnTe Detectors

    CERN Document Server

    Födisch, P; Lange, B; Kirschke, T; Enghardt, W; Kaever, P

    2016-01-01

    Cadmium zinc telluride (CdZnTe, "CZT") radiation detectors are announced to be a game-changing detector technology. However, state-of-the-art detector systems require high-performance readout electronics as well. Even though an application-specific integrated circuit (ASIC) is an adequate solution for the readout, our demands on a high dynamic range for energy measurement and a high throughput are not served by any commercially available circuit. Consequently, we had to develop the analog front-end electronics with operational amplifiers for an 8x8 pixelated CZT detector. For this purpose, we model an electrical equivalent circuit of the CZT detector with the associated charge-sensitive amplifier (CSA). Therefore, we present the mathematical equations for a detailed network analysis. Additionally, we enhance the design with numerical values for various features such as ballistic deficit, charge-to-voltage gain, rise time, noise level and verify the performance with synthetic detector signals. With this benchm...

  5. Growth of CdZnTe Crystals for Radiation Detector Applications by Directional Solidification

    Science.gov (United States)

    Su, Ching-Hua

    2014-01-01

    Advances in Cadmium Zinc Telluride (Cd(sub 1-x)Zn(sub x)Te) growth techniques are needed for the production of large-scale arrays of gamma and x-ray astronomy. The research objective is to develop crystal growth recipes and techniques to obtain large, high quality CdZnTe single crystal with reduced defects, such as charge trapping, twinning, and tellurium precipitates, which degrade the performance of CdZnTe and, at the same time, to increase the yield of usable material from the CdZnTe ingot. A low gravity material experiment, "Crystal Growth of Ternary Compound Semiconductors in Low Gravity Environment", will be performed in the Material Science Research Rack (MSRR) on International Space Station (ISS). One section of the flight experiment is the melt growth of CdZnTe ternary compounds. This talk will focus on the ground-based studies on the growth of Cd(sub 0.80)Zn(sub 0.20)Te crystals for radiation detector applications by directional solidification. In this investigation, we have improved the properties that are most critical for the detector applications (electrical properties and crystalline quality): a) Electrical resistivity: use high purity starting materials (with reproducible impurity levels) and controlled Cd over pressure during growth to reproducibly balance the impurity levels and Cd vacancy concentration b) Crystalline quality: use ultra-clean growth ampoule (no wetting after growth), optimized thermal profile and ampoule design, as well as a technique for supercool reduction to growth large single crystal with high crystalline quality

  6. Characterization of coplanar grid CZT detectors with highly collimated x-ray beam

    Science.gov (United States)

    Carini, Gabriella A.; Bolotnikov, Aleksey E.; Camarda, Giuseppe S.; Wright, Gomez W.; De Geronimo, Gianluigi; Siddons, D. P.; James, Ralph B.

    2004-10-01

    CdZnTe detectors demonstrated great potentials for detection of gamma radiation. However, energy resolution of CdZnTe detectors is significantly affected by uncollected holes which have low mobility and short lifetime. To overcome this deleterious effects upon energy resolution special detector designs have to be implemented. The most practical of them are the small pixel effect device, the co-planar grid device, and the virtual Frisch-grid device. We routinely use a highly collimated high-intensity X-ray beams provided by National Synchrotron Light Source (NSLS) facility at Brookhaven National Laboratory to study of CdZnTe material and performances of the different types of devices on the micron-scale. This powerful tool allows us to evaluate electronic properties of the material, device performance, uniformity of the detector responses, effects related to the device's contact pattern and electric field distribution, etc. In particular, in this paper we present new results obtained from the performance studies of 15 x 15 x 7.5 mm3 coplanar-grid devices coupled to readout ASIC. We observed the effect of the strip contacts comprising the grids on the energy resolution of the coplanar-grid device.

  7. CdZnTe Frisch collar detectors for {gamma}-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kargar, Alireza [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Jones, Andrew M. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); McNeil, Walter J. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Harrison, Mark J. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)]. E-mail: mcgregor@ksu.edu

    2006-03-15

    Low-energy {gamma}-ray spectra were collected from {sup 241}Am, {sup 57}Co, {sup 133}Ba, {sup 198}Au, {sup 137}Cs and {sup 235}U using a 3.4x3.4x5.7 mm{sup 3} CdZnTe detector utilizing an insulated Frisch ring. The CdZnTe detector was fabricated from a single crystal and a copper shim was used as the Frisch collar. Room-temperature energy resolution of 1.45% full-width half-maximum (FWHM) was obtained for {sup 137}Cs at 661.7 keV without electronic correction. The detector fabrication process is described and the resulting energy spectra are discussed. The detector fabrication process is described and the resulting energy spectra are discussed. The detector full-energy-peak intrinsic efficiency is reported for different {gamma}-ray energies, specifically from {sup 241}Am, {sup 57}Co, {sup 133}Ba and {sup 137}Cs.

  8. HAND-HELD GAMMA-RAY SPECTROMETER BASED ON HIGH-EFFICIENCY FRISCH-RING CdZnTe DETECTORS.

    Energy Technology Data Exchange (ETDEWEB)

    CUI,Y.

    2007-05-01

    Frisch-ring CdZnTe detectors have demonstrated good energy resolution, el% FWHM at 662 keV, and good efficiency for detecting gamma rays. This technique facilitates the application of CdZnTe materials for high efficiency gamma-ray detection. A hand-held gamma-ray spectrometer based on Frisch-ring detectors is being designed at Brookhaven National Laboratory. It employs an 8x8 CdZnTe detector array to achieve a high volume of 19.2 cm3, so that detection efficiency is significantly improved. By using the front-end ASICs developed at BNL, this spectrometer has a small profile and high energy resolution. The spectrometer includes signal processing circuit, digitization and storage circuit, high-voltage module, and USB interface. In this paper, we introduce the details of the system structure and report our test results with it.

  9. Low noise CMOS readout for CdZnTe detector arrays

    CERN Document Server

    Jakobson, C G; Lev, S B; Nemirovsky, Y

    1999-01-01

    A low noise CMOS readout for CdTe and CdZnTe X- and gamma-ray detector arrays has been designed and implemented in the CMOS 2 mu m low noise analog process provided by the multi-chip program of Metal Oxide Semiconductor Implementation Service. The readout includes CMOS low noise charge sensitive preamplifier and a multiplexed semi-Gaussian pulse shaper. Thus, each detector has a dedicated charge sensitive preamplifier that integrates its signal, while a single shaping amplifier shapes the pulses after the multiplexer. Low noise and low-power operation are achieved by optimizing the input transistor of the charge sensitive preamplifier. Two optimization criteria are used to reduce noise. The first criterion is based on capacitance matching between the input transistor and the detector. The second criterion is based on bandwidth optimization, which is obtained by tailoring the shaper parameters to the particular noise mechanisms of the MOS transistor and the CdZnTe detector. Furthermore, the multiplexing functi...

  10. Low noise CMOS readout for CdZnTe detector arrays

    Energy Technology Data Exchange (ETDEWEB)

    Jakobson, C.G.; Asa, G.; Lev, S. Bar; Nemirovsky, Y. E-mail: nemirov@ee.technion.ac.il

    1999-06-01

    A low noise CMOS readout for CdTe and CdZnTe X- and gamma-ray detector arrays has been designed and implemented in the CMOS 2 {mu}m low noise analog process provided by the multi-chip program of Metal Oxide Semiconductor Implementation Service. The readout includes CMOS low noise charge sensitive preamplifier and a multiplexed semi-Gaussian pulse shaper. Thus, each detector has a dedicated charge sensitive preamplifier that integrates its signal, while a single shaping amplifier shapes the pulses after the multiplexer. Low noise and low-power operation are achieved by optimizing the input transistor of the charge sensitive preamplifier. Two optimization criteria are used to reduce noise. The first criterion is based on capacitance matching between the input transistor and the detector. The second criterion is based on bandwidth optimization, which is obtained by tailoring the shaper parameters to the particular noise mechanisms of the MOS transistor and the CdZnTe detector. Furthermore, the multiplexing function incorporated in the shaper provides low power and reduces chip area. The system is partitioned into a chip containing the charge amplifiers and a chip containing the semi-Gaussian pulse shaper and multiplexer. This architecture minimizes coupling from multiplexer switches as well as shaper output to the input of the charge sensitive preamplifiers.

  11. Progress in the Development of CdZnTe Unipolar Detectors for Different Anode Geometries and Data Corrections

    Directory of Open Access Journals (Sweden)

    Qiushi Ren

    2013-02-01

    Full Text Available CdZnTe detectors have been under development for the past two decades, providing good stopping power for gamma rays, lightweight camera heads and improved energy resolution. However, the performance of this type of detector is limited primarily by incomplete charge collection problems resulting from charge carriers trapping. This paper is a review of the progress in the development of CdZnTe unipolar detectors with some data correction techniques for improving performance of the detectors. We will first briefly review the relevant theories. Thereafter, two aspects of the techniques for overcoming the hole trapping issue are summarized, including irradiation direction configuration and pulse shape correction methods. CdZnTe detectors of different geometries are discussed in detail, covering the principal of the electrode geometry design, the design and performance characteristics, some detector prototypes development and special correction techniques to improve the energy resolution. Finally, the state of art development of 3-D position sensing and Compton imaging technique are also discussed. Spectroscopic performance of CdZnTe semiconductor detector will be greatly improved even to approach the statistical limit on energy resolution with the combination of some of these techniques.

  12. Analysis of trapping and de-trapping in CdZnTe detectors by Pockels effect

    Science.gov (United States)

    Rejhon, M.; Franc, J.; Dědič, V.; Kunc, J.; Grill, R.

    2016-09-01

    In this contribution we introduce a method of deep level spectroscopy in semi-insulating semiconductors demonstrated on detector-grade bulk CdZnTe. The method is based on the measurements of temporal and temperature evolution of the electric field profile in studied samples, which is very sensitive to a change of occupancy of deep levels. The measurement of the electric field is based on the linear electro-optic (Pockels) effect using the InGaAs avalanche photodiode with fast response. The internal electric field profile in studied samples significantly changes under various external conditions represented by the application of the bias and pulsed illumination with below-bandgap light. From the knowledge of the electric field behavior and using a standard analysis based on thermally induced transitions of electrons and holes from the deep levels to the conduction and valence bands, respectively, it is possible to get activation energies of the energy levels, their types (donor or acceptor) and corresponding capture cross-sections. By this method we have found deep levels responsible for the polarization of CdZnTe detector under high photon-fluxes. Identified deep levels {{E}\\text{v}}+0.41 eV, {{E}\\text{v}}+0.77 eV and {{E}\\text{v}}+0.94 eV can capture the photo-generated holes and thus form a positive space charge, which is responsible for polarization of the detector.

  13. 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.

  14. Charge sharing in common-grid pixelated CdZnTe detectors

    Science.gov (United States)

    Kim, Jae Cheon; Anderson, Stephen E.; Kaye, Willy; Zhang, Feng; Zhu, Yuefeng; Kaye, Sonal Joshi; He, Zhong

    2011-10-01

    The charge sharing effect in pixelated CdZnTe (CZT) detectors with a common anode steering grid has been studied. The impact on energy resolution of weighting potential cross-talk and ballistic deficit due to cathode signal shaping has been investigated. A detailed system modeling package considering charge induction, electronic noise, pulse shaping, and ASIC triggering procedures has been developed to study the characteristics of common-grid CZT detectors coupled to the VAS_UM/TAT4 ASIC. Besides an actual common-grid CZT detector coupled to VAS_UM/TAT4 ASIC, a prototype digital read-out system has been developed to better understand the nature of the charge sharing effect.

  15. Charge sharing in common-grid pixelated CdZnTe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Cheon, E-mail: jaecheon@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Anderson, Stephen E.; Kaye, Willy; Zhang Feng; Zhu Yuefeng; Kaye, Sonal Joshi; He Zhong [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2011-10-21

    The charge sharing effect in pixelated CdZnTe (CZT) detectors with a common anode steering grid has been studied. The impact on energy resolution of weighting potential cross-talk and ballistic deficit due to cathode signal shaping has been investigated. A detailed system modeling package considering charge induction, electronic noise, pulse shaping, and ASIC triggering procedures has been developed to study the characteristics of common-grid CZT detectors coupled to the VAS{sub U}M/TAT4 ASIC. Besides an actual common-grid CZT detector coupled to VAS{sub U}M/TAT4 ASIC, a prototype digital read-out system has been developed to better understand the nature of the charge sharing effect.

  16. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays

    Directory of Open Access Journals (Sweden)

    Jakub Pekárek

    2016-09-01

    Full Text Available This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm − 2 ·s − 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

  17. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays.

    Science.gov (United States)

    Pekárek, Jakub; Dědič, Václav; Franc, Jan; Belas, Eduard; Rejhon, Martin; Moravec, Pavel; Touš, Jan; Voltr, Josef

    2016-09-27

    This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm - 2 ·s - 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A., E-mail: nuclearengg@gmail.com [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States); Geuther, Jeffrey A. [TRIGA Mark II Nuclear Reactor, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States); Neihart, James L.; Riedel, Todd A. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States); Rojeski, Ronald A. [Nanometrics, Inc., 1550 Buckeye Drive, Milpitas CA 95035 (United States); Ugorowski, Philip B.; McGregor, Douglas S. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering, Kansas State University, Manhattan KS 66506 (United States)

    2012-07-11

    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 {sup 10}B-lined counter.

  19. Intensifying process of polarization effect within pixellated CdZnTe detectors for X-ray imaging

    Institute of Scientific and Technical Information of China (English)

    Xi Wang; Shali Xiao; Miao Li; Liuqiang Zhang; Yulin Cao; Yuxiao Chen

    2011-01-01

    The intensifying process of polarization effect at room temperature in a pixellated Cadmium zinc telluride (CdZnTe) monolithic detector is studied.The process is attributed to the increase in build up space charges in the CdZnTe crystal,which causes an expansion of the space charge region under the irradiated area.The simulations of electric potential distributions indicate that the distorted electric potential due to the high X-ray flux is significantly changed and even deteriorated due to increasing space charges within the irradiated volume.An agreement between the space charge distribution and electric potential is discussed.

  20. CdZnTe drift detector with correction for hole trapping

    DEFF Research Database (Denmark)

    van Pamelen, M.A.J.; Budtz-Jørgensen, Carl

    1998-01-01

    The results are presented of a CdZnTe drift detector for which the energy determination can be corrected for hole trapping. The electronic noise and the hole contribution to the signal are reduced and the signals are also corrected for any residual effects of hole trapping. This is achieved...... by using drift strips and an anode strip on one side of the detector crystal in combination with a single planar electrode on the other side. Below 100 keV, the resolution tin FWHM) was electronic noise limited. Using a planar electrode, the peak of Am-241 at 59.6 keV has a width of 14.1 ke...

  1. CdTe and CdZnTe crystals for room temperature gamma-ray detectors

    CERN Document Server

    Franc, J; Belas, E; Grill, R; Hlidek, P; Moravec, P; Bok, J B

    1999-01-01

    CdTe(Cl) detectors from CdTe single crystals, grown by the Bridgman method from Te-rich melt, were fabricated. The quality of the detectors was tested with sup 5 sup 7 Co and sup 2 sup 4 sup 1 Am sources. In the sup 5 sup 7 Co spectrum low noise is demonstrated by the presence of a 14 keV peak and good resolution approx 7 keV (FWHM) evident from the separation of 122 and 136 keV peaks. A review is given of the state-of-the-art properties of (CdZn)Te single crystals prepared for substrates in the Institute of Physics of Charles University. The quality of samples is tested by measurements of the diffusion length of minority carriers, from which the mobility-lifetime product is evaluated. (author)

  2. Charge-sensitive front-end electronics with operational amplifiers for CdZnTe detectors

    Science.gov (United States)

    Födisch, P.; Berthel, M.; Lange, B.; Kirschke, T.; Enghardt, W.; Kaever, P.

    2016-09-01

    Cadmium zinc telluride (CdZnTe, CZT) radiation detectors are suitable for a variety of applications, due to their high spatial resolution and spectroscopic energy performance at room temperature. However, state-of-the-art detector systems require high-performance readout electronics. Though an application-specific integrated circuit (ASIC) is an adequate solution for the readout, requirements of high dynamic range and high throughput are not available in any commercial circuit. Consequently, the present study develops the analog front-end electronics with operational amplifiers for an 8×8 pixelated CZT detector. For this purpose, we modeled an electrical equivalent circuit of the CZT detector with the associated charge-sensitive amplifier (CSA). Based on a detailed network analysis, the circuit design is completed by numerical values for various features such as ballistic deficit, charge-to-voltage gain, rise time, and noise level. A verification of the performance is carried out by synthetic detector signals and a pixel detector. The experimental results with the pixel detector assembly and a 22Na radioactive source emphasize the depth dependence of the measured energy. After pulse processing with depth correction based on the fit of the weighting potential, the energy resolution is 2.2% (FWHM) for the 511 keV photopeak.

  3. Direct conversion Si and CdZnTe detectors for digital mammography

    CERN Document Server

    Yin Shi Shi; Maeding, D; Mainprize, J; Mawdsley, G; Yaffe, M J; Gordon, E E; Hamilton, W J

    2000-01-01

    Hybrid pixel detector arrays that convert X-rays directly into charge signals are under development at NOVA for application to digital mammography. This technology also has wide application possibilities in other fields of radiology or in industrial imaging, nondestructive evaluation (NDE) and nondestructive inspection (NDI). These detectors have potentially superior properties compared to either emulsion-based film-screen systems which has nonlinear response to X-rays, or phosphor-based detectors in which there is an intermediate step of X-ray to light photon conversion (Feig and Yaffe, Radiol. Clinics North America 33 (1995) 1205-1230). Potential advantages of direct conversion detectors are high quantum efficiencies (QE) of 98% or higher (for 0.3 mm thick CdZnTe detector with 20 keV X-rays), improved contrast, high sensitivity and low intrinsic noise. These factors are expected to contribute to high detective quantum efficiency (DQE). The prototype hybrid pixel detector developed has 50x50 mu m pixel size,...

  4. Cooled CdZnTe detectors for X-ray astronomy

    CERN Document Server

    Bale, G; Seller, P; Lowe, B

    1999-01-01

    Recent results combining thermoelectrically cooled CdZnTe detectors with a low-noise Pentafet preamplifier are presented. Cooling between -30 deg. C and -40 deg. C reduces the leakage current of the detectors and allows the use of a pulsed reset preamplifier and long shaping times, significantly improving the energy resolution. Mn K subalpha X-rays at 5.9 keV have been observed with a resolution of less than 280 eV FWHM and a peak to background of more than 200:1. The Fano factor of the material has been estimated at 0.11+-0.012 at -40 deg. C. The detector requirement for X-ray astronomy will be a photon-counting imaging spectrometer. A 16x16 element, bump bonded pixel detector is described and results from a prototype silicon array presented. The detector is constructed with ASIC amplifiers with a system noise of <25 electrons rms and should give an energy resolution comparable to the Pentafet results presented here.

  5. Development of CdZnTe X-ray detectors at DSRI

    DEFF Research Database (Denmark)

    van Pamelen, M.A.J.; Budtz-Jørgensen, Carl; Kuvvetli, Irfan

    2000-01-01

    An overview of the development of CdZnTe X-ray detectors at the Danish Space Research Institute is presented. Initiated in the beginning of 1996, the main motivation at that time was to develop focal plane detectors for the novel type of hard X-ray telescopes, which are currently under study at D...... trapping has now little influence and the spectrum displays a pronounced Gaussian peak at 661 keV with a width (FWHM) of 6.9 keV. Also a small peak produced by CdTe escape events can now be observed. At the same time, no events have to be rejected....... at DSRI. With the advent of the Danish Micro Satellite program it was, however, recognised that this type of detector is very well suited for two proposed missions (eXCALIBur, AXO). The research at DSRI has so far been concentrated on the spectroscopic properties of the CZT detector. At DSRI we have...

  6. Evaluation of ZnO:Al as a contact material to CdZnTe for radiation detector applications (Conference Presentation)

    Science.gov (United States)

    Roy, Utpal N.; Camarda, Giuseppe S.; Cui, Yonggang; Gul, Rubi; Hossain, Anwar; Yang, Ge; James, Ralph B.; Pradhan, Aswini K.; Mundle, Rajeh

    2016-09-01

    Aluminum (Al) doped ZnO with very high Al concentration acts as metal regarding its electrical conductivity. ZnO offers many advantages over the commonly-known metals being used today as electrode materials for nuclear detector fabrication. Often, the common metals show poor adhesion to CdZnTe or CdTe surfaces and have a tendency to peel off. In addition, there is a large mismatch of the coefficients of thermal expansion (CTE) between the metals and underlying CdZnTe, which is one of the reasons for mechanical degradation of the contact. In contrast ZnO has a close match of the CTE with CdZnTe and possesses 8-20 times higher hardness than the commonly-used metals. In this presentation, we will explore and discuss the properties of CdZnTe detectors with ZnO:Al contacts.

  7. CdTe and CdZnTe gamma ray detectors for medical and industrial imaging systems

    CERN Document Server

    Eisen, Y; Mardor, I

    1999-01-01

    CdTe and CdZnTe X-ray and gamma ray detectors in the form of single elements or as segmented monolithic detectors have been shown to be useful in medical and industrial imaging systems. These detectors possess inherently better energy resolution than scintillators coupled to either photodiodes or photomultipliers, and together with application specific integrated circuits they lead to compact imaging systems of enhanced spatial resolution and better contrast resolution. Photopeak efficiencies of these detectors is greatly affected by a relatively low hole mobility-lifetime product. Utilizing these detectors as highly efficient good spectrometers, demands use of techniques to improve their charge collection properties, i.e., correct for variations in charge losses at different depths of interaction in the detector. The corrections for the large hole trapping are made either by applying electronic techniques or by fabricating detector or electrical contacts configurations which differ from the commonly used pla...

  8. Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications

    Directory of Open Access Journals (Sweden)

    Anna Maria Mancini

    2009-05-01

    Full Text Available Over the last decade, cadmium telluride (CdTe and cadmium zinc telluride (CdZnTe wide band gap semiconductors have attracted increasing interest as X-ray and gamma ray detectors. Among the traditional high performance spectrometers based on silicon (Si and germanium (Ge, CdTe and CdZnTe detectors show high detection efficiency and good room temperature performance and are well suited for the development of compact and reliable detection systems. In this paper, we review the current status of research in the development of CdTe and CdZnTe detectors by a comprehensive survey on the material properties, the device characteristics, the different techniques for improving the overall detector performance and some major applications. Astrophysical and medical applications are discussed, pointing out the ongoing Italian research activities on the development of these detectors.

  9. Progress in the Development of CdTe and CdZnTe Semiconductor Radiation Detectors for Astrophysical and Medical Applications.

    Science.gov (United States)

    Sordo, Stefano Del; Abbene, Leonardo; Caroli, Ezio; Mancini, Anna Maria; Zappettini, Andrea; Ubertini, Pietro

    2009-01-01

    Over the last decade, cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) wide band gap semiconductors have attracted increasing interest as X-ray and gamma ray detectors. Among the traditional high performance spectrometers based on silicon (Si) and germanium (Ge), CdTe and CdZnTe detectors show high detection efficiency and good room temperature performance and are well suited for the development of compact and reliable detection systems. In this paper, we review the current status of research in the development of CdTe and CdZnTe detectors by a comprehensive survey on the material properties, the device characteristics, the different techniques for improving the overall detector performance and some major applications. Astrophysical and medical applications are discussed, pointing out the ongoing Italian research activities on the development of these detectors.

  10. Comparison of CdTe and CdZnTe Detectors for Field Determination of Uranium Isotopic Enrichments

    Energy Technology Data Exchange (ETDEWEB)

    Hofstetter, KJ

    2004-01-23

    A performance comparison of a CdTe and a CdZnTe detector when exposed to uranium samples of various isotopic enrichments has been performed. These high-resolution detectors can assist in the rapid determination of uranium isotopic content of illicit material. Spectra were recorded from these room temperature semiconductor detectors with a portable multi-channel analyzer, both in the laboratory and in a field environment. Both detectors were operated below ambient temperature using the vendor supplied thermoelectric coolers. Both detectors had nominally the same active volume (18 mm3 for the CdZnTe and 25 mm3 for the CdTe detector) and resolution. Spectra of samples of known isotopic content were recorded at fixed geometries. An evaluation of potential signature g rays for the detection of enriched uranium was completed. Operational advantages and disadvantages of each detector are discussed. There is a need to improve the detection sensitivity during the interdiction of special nuclear materials (SNM) for increased homeland protection. It is essential to provide additional tools to first responders and law enforcement personnel for assessing nuclear and radiological threats.

  11. Signal modeling of charge sharing effect in simple pixelated CdZnTe detector

    Science.gov (United States)

    Kim, Jae Cheon; Kaye, William R.; He, Zhong

    2014-05-01

    In order to study the energy resolution degradation in 3D position-sensitive pixelated CdZnTe (CZT) detectors, a detailed detector system modeling package has been developed and used to analyze the detector performance. A 20 × 20 × 15 mm3 CZT crystal with an 11 × 11 simple-pixel anode array and a 1.72 mm pixel pitch was modeled. The VAS UM/TAT4 Application Specific Integrated Circuitry (ASIC) was used for signal read-out. Components of the simulation package include gamma-ray interactions with the CZT crystal, charge induction, electronic noise, pulse shaping, and ASIC triggering procedures. The charge induction model considers charge drift, trapping, diffusion, and sharing between pixels. This system model is used to determine the effects of electron cloud sharing, weighting potential non-uniformity, and weighting potential cross-talk which produce non-uniform signal responses for different gamma-ray interaction positions and ultimately degrade energy resolution. The effect of the decreased weighting potential underneath the gap between pixels on the total pulse amplitude of events has been studied. The transient signals induced by electron clouds collected near the gap between pixels may generate false signals, and the measured amplitude can be even greater than the photopeak. As the number of pixels that collect charge increases, the probability of side-neighbor events due to charge sharing significantly increases. If side-neighbor events are not corrected appropriately, the energy resolution of pixelated CZT detectors in multiple-pixel events degrades rapidly.

  12. Signal modeling of charge sharing effect in simple pixelated CdZnTe detector

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae C.; Kaye, William R.; He, Zhong [University of Michigan, Ann Arbor, MI (United States)

    2014-05-15

    In order to study the energy resolution degradation in 3D position-sensitive pixelated CdZnTe (CZT) detectors, a detailed detector system modeling package has been developed and used to analyze the detector performance. A 20 x 20 x 15 mm{sup 3} CZT crystal with an 11 x 11 simple-pixel anode array and a 1.72 mm pixel pitch was modeled. The VAS UM/TAT4 Application Specific Integrated Circuitry (ASIC) was used for signal read-out. Components of the simulation package include gamma-ray interactions with the CZT crystal, charge induction, electronic noise, pulse shaping, and ASIC triggering procedures. The charge induction model considers charge drift, trapping, diffusion, and sharing between pixels. This system model is used to determine the effects of electron cloud sharing, weighting potential non-uniformity, and weighting potential cross-talk which produce non-uniform signal responses for different gamma-ray interaction positions and ultimately degrade energy resolution. The effect of the decreased weighting potential underneath the gap between pixels on the total pulse amplitude of events has been studied. The transient signals induced by electron clouds collected near the gap between pixels may generate false signals, and the measured amplitude can be even greater than the photopeak. As the number of pixels that collect charge increases, the probability of side-neighbor events due to charge sharing significantly increases. If side-neighbor events are not corrected appropriately, the energy resolution of pixelated CZT detectors in multiple-pixel events degrades rapidly.

  13. Influence of the thickness of a crystal on the electrical characteristics of Cd(Zn)Te detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sklyarchuk, V. [Chernivtsi National Univ. (Ukraine); Fochuk, p. [Chernivtsi National Univ. (Ukraine); Rarenko, I. [Chernivtsi National Univ. (Ukraine); Zakharuk, Z. [Chernivtsi National Univ. (Ukraine); Sklyarchuk, O. F. [Chernivtsi National Univ. (Ukraine); Bolotnikov, A. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); James, R. B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-08-01

    We studied the electrical characteristics of Cd(Zn)Te detectors with rectifying contacts and varying thicknesses, and established that their geometrical dimensions affect the measured electrical properties. We found that the maximum value of the operating-bias voltage and the electric field in the detector for acceptable values of the dark current can be achieved when the crystal has an optimum thickness. This finding is due to the combined effect of generation-recombination in the space-charge region and space-charge limited currents (SCLC).

  14. Point Defects in Pb-, Bi-, and In-Doped CdZnTe Detectors: Deep-Level Transient Spectroscopy (DLTS) Measurements

    Science.gov (United States)

    Gul, R.; Keeter, K.; Rodriguez, R.; Bolotnikov, A. E.; Hossain, A.; Camarda, G. S.; Kim, K. H.; Yang, G.; Cui, Y.; Carcelen, V.; Franc, J.; Li, Z.; James, R. B.

    2012-03-01

    We studied, by current deep-level transient spectroscopy (I-DLTS), point defects induced in CdZnTe detectors by three dopants: Pb, Bi, and In. Pb-doped CdZnTe detectors have a new acceptor trap at around 0.48 eV. The absence of a VCd trap suggests that all Cd vacancies are compensated by Pb interstitials after they form a deep-acceptor complex [[PbCd]+-V{Cd/2-}]-. Bi-doped CdZnTe detectors had two distinct traps: a shallow trap at around 36 meV and a deep donor trap at around 0.82 eV. In detectors doped with In, we noted three well-known traps: two acceptor levels at around 0.18 eV (A-centers) and 0.31 eV (VCd), and a deep trap at around 1.1 eV.

  15. Development of CDZNTE Detectors for Low-Energy Gamma-Ray Astronomy

    Science.gov (United States)

    Gehrels, N.

    1999-01-01

    Under this grant the UC Berkeley PI, K. Hurley, joined a Goddard-led effort to develop large area, multi-pixel Cadmium-Zinc-Telluride (CdZnTe, or CZT) detectors for gamma-ray astronomy. His task was to advise the project of new developments in the area of cosmic gamma-ray bursts, in order to focus the detector development effort on the construction of an instrument which could be deployed on a spacecraft to localize and measure the energy spectra of bursts with good angular and energy resolution, respectively. UC Berkeley had no hardware role in this proposal. The result of this effort was the production, at Goddard, of five CZT prototype modules. A proposal was written for SWIFT, a MIDEX mission to study cosmic gamma-ray bursts. One experiment aboard SWIFT is the Burst Arcminute Telescope (BAT), which consists of a 5200 sq cm hard X-ray detector and a coded mask. The detector comprises 256 CZT modules, each containing 128 4 x 4 x 2 mm CZT detectors. Each detector is read out using an ASIC. The angular resolution achieved with this mask/array combination is 22 arcminutes, and a strong gamma-ray burst can be localized to an accuracy of 4 arcminutes in under 10 seconds. The energy resolution is typically 5 keV FWHM at 60 keV, and the energy range is 10 - 150 keV. The BAT views 2 steradians, and its sensitivity is such that the instrument can detect 350 gamma-ray burst/year, localizing 320 of them to better than 4 arcminute accuracy. The BAT concept therefore met the science goals for gamma-ray bursts. The UCB effort in the SWIFT proposal included the scientific objectives for gamma-ray bursts, and the assembly of a team of optical and radio observers who would use the BAT data to perform rapid multi-wavelength searches for the counterparts to bursts. This proposal was submitted to NASA and peer-reviewed. In January 1999 it was one of five such proposals selected for a Phase A study. This study was completed in June, and SWIFT was formally presented to NASA in

  16. Discrimination of alpha particles in CdZnTe detectors with coplanar grid for the COBRA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rebber, Henning [Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Collaboration: COBRA-Collaboration

    2016-07-01

    The aim of the COBRA experiment is the search for neutrinoless double beta decay using CdZnTe semiconductor detectors. A background rate in the order of 10{sup -3} counts per keV, kg and year is intended in order to be sensitive to a half-life larger than 10{sup 26} years. Measurements from a demonstrator setup and Monte Carlo simulations indicate that a large background component is due to alpha particles. These generate charge clouds of only few μm in diameter in the detector, leading to characteristic pulse features. Parameter-based cut criteria were developed to discriminate alpha events by means of their pulse shapes. The cuts were tested on data from alpha and beta irradiation of a (1 x 1 x 1) cm{sup 3} CdZnTe detector with coplanar grid. The pulse shapes of all event signals were read out by FADCs with a sampling rate of 100 MHz. The signals were reproduced by a detector simulation which hence was used to study the cuts for energies up to 3 MeV and different detector regions.

  17. Electronic properties of traps induced by gamma-irradiation in CdTe and CdZnTe detectors

    CERN Document Server

    Cavallini, A; Chirco, P; Morigi, M P; Zanarini, M; Auricchio, N; Caroli, E; Dusi, W; Fougeres, P; Hage-Ali, M; Siffert, P

    2000-01-01

    The knowledge of a detector response to different types of radiation sources is becoming a key issue for its employment in many medical, space and scientific applications. Nevertheless, a clear understanding of the effects of irradiation on the material properties is still a long way ahead and, therefore, we have started a thorough investigation of room temperature CdTe and CdZnTe detectors exposed to gamma-ray irradiation. As-grown detectors have been exposed to increasing gamma-ray doses, up to the virtual death of the detector, which occurs at a dose of 30 kGy. The modifications in the detector performance have been investigated by dark-current measurements and quantitative spectroscopic analyses at low and medium energies. The deep levels present in the material have been identified by means of Photo-Induced Current Transient Spectroscopy (PICTS) analyses. The evolution of the trap parameters with increasing irradiation dose has been monitored and a comparison of the results obtained from CdTe and CdZnTe ...

  18. CdTe and CdZnTe detectors behavior in X-ray computed tomography conditions

    CERN Document Server

    Ricq, S; Garcin, M

    2000-01-01

    The application of CdTe and CdZnTe 2D array detectors for medical X-ray Computed Tomography (XCT) is investigated. Different metallic electrodes have been deposited on High-Pressure Bridgman Method CdZnTe and on Traveling Heater Method CdTe:Cl. These detectors are exposed to X-rays in the CT irradiation conditions and are characterized experimentally in current mode. Detectors performances such as sensitivity and response speed are studied. They are correlated with charge trapping and de-trapping. The trapped carrier space charges may influence the injection from the electrodes. This enables one to get information on the nature of the predominant levels involved. The performances achieved are encouraging: dynamic ranges higher than 4 decades and current decreases of 3 decades in 4 ms after X-ray beam cut-off are obtained. Nevertheless, these detectors are still limited by high trap densities responsible for the memory effect that makes them unsuitable for XCT.

  19. An effect of the networks of the subgrain boundaries on spectral responses of thick CdZnTe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, A.; Butcher, J.; Camarda, G.; Cui, Y.; Egarievwe, S.; Fochuk, P.; Gul,R.; Hamade, M.; Hossain, A.; Kim, K.; Kopach,O.; Petryk, M.; Raghothamachar, B.; Yang, G.; and James, R.B.

    2011-08-12

    CdZnTe (CZT) crystals used for nuclear-radiation detectors often contain high concentrations of subgrain boundaries and networks of poligonized dislocations that can significantly degrade the performance of semiconductor devices. These defects exist in all commercial CZT materials, regardless of their growth techniques and their vendor. We describe our new results from examining such detectors using IR transmission microscopy and white X-ray beam diffraction topography. We emphasize the roles on the devices performances of networks of subgrain boundaries with low dislocation densities, such as poligonized dislocations and mosaic structures. Specifically, we evaluated their effects on the gamma-ray responses of thick, >10 mm, CZT detectors. Our findings set the lower limit on the energy resolution of CZT detectors containing dense networks of subgrain boundaries, and walls of dislocations.

  20. Setup and characterization of a Frisch grid ionization chamber for the spectroscopy of low specific activities; Aufbau und Charakterisierung einer Frisch-Gitterionisationskammer fuer die Spektroskopie niedrigster spezifischer Aktivitaeten

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Felix

    2013-12-19

    The realization of this work was the usage of a Frisch grid ionization chamber for measuring the lowest specific alpha activity. In the practical case the detector should be used to remeasure the half life of {sup 144}Nd. Only very thin targets can be used, due to the extreme long half life and the very short range of alpha particles in matter. The area of the samples must be big enough to get the required activity. In comparison gridded ionization chambers are the most practical devices. The chamber was realized in that way, that two gridded chambers shares a common anode. This could be used to minimize the detector background. The charge, which was induced in the detector electrodes, is acquired by an analog to digital converter. The full analysis of the data is done after the measurement. With the pulse form analysis it is possible to extract information about every event occurring in the detector. It is also possible to correct the grid inefficiency and the correlated angle dependence of the pulse height. This improves the energy resolution. A resolution of 0.86 % at 5.1 MeV is possible. The characterization of the events is also used for the suppression of the detector background. Due to different conditions for an assumed alpha event the majority of the events which disturbs the measurement could be removed. So it is possible to suppress the background in the range between 1 MeV to 2.2 MeV of 435 events per day without the characterization to 21.6 events per day with characterization, which is a factor of roughly 20. The detection efficiency is not noticeably effected. For sufficiently long measurements a lowest limit of detection of 10 counts per day is expectable. For a target geometry which can be used with this setup, about 50 alpha decays of {sup 144}Nd per day will occur. With a detection efficiency a bit below 50 % the measurement on {sup 144}Nd should be possible.

  1. Recent advances in Tl Br, Cd Te and CdZnTe semiconductor radiation detectors: a review

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Icimone B. [Universidade Bandeirante (UNIBAN), Sao Paulo, SP (Brazil)

    2011-07-01

    The success in the development of radiation spectrometers operating at room temperature is based on many years of effort on the part of large numbers of workers around the world. These individuals have contributed to the understanding of the fundamental materials issues associated with the growth of semiconductors for this application, the development of device fabrication and processing technology, and advances in low noise electronics and pulse processing. Progress in this field continues at an accelerated pace, as in evidenced by the improvements in detector performance and by the growing number of commercial products. Thus, the last years have been seen continued effort in the development of room temperature compound semiconductors devices. High-Z compound semiconductor detectors has been explored for high energy resolution, high detection efficiency and are of low cost. Compound semiconductors detectors are well suited for addressing needs of demanding applications such as bore hole logging where high operating temperature are encountered. In this work recent developments in semiconductors detectors were reviewed. This review concentrated on thallium bromide (TlBr), cadmium zinc telluride (CdZnTe) and cadmium telluride (CdTe) crystals detectors. TlBr has higher stopping power compared to common semiconductor materials because it has the higher photoelectric and total attenuation coefficients over wide energy range from 100 keV to 1 MeV. CdTe and CdZnTe detectors have several attractive features for detecting X-ray and low energy gamma ray. Their relatively large band gaps lead to a relatively low leakage current and offer an excellent energy resolution at room temperature. A literature survey and bibliography was also included. (author)

  2. Parallel readout of two-element CdZnTe detectors with real-time digital signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Shi Zhubin; Wang Linjun; Qin Kaifeng; Min Jiahua; Zhang Jijun; Liang Xiaoyan; Huang Jian; Tang Ke; Xia Yiben, E-mail: ljwang@shu.edu.cn [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

    2010-12-15

    Readout electronics, especially digital electronics, for two-element CdZnTe (CZT) detectors in parallel are developed. The preliminary results show the detection efficiency of the two-element CZT detectors in parallel with analog electronics is as many as 1.8 and 2.1 times the single ones, and the energy resolution (FWHM) is limited by that of the single one by the means of analog electronics. However, the digital method for signal processing will be sufficiently better by contrast with an analog method especially in energy resolution. The energy resolution by the means of digital electronics can be improved by about 26.67%, compared to that only with analog electronics, while their detection efficiency is almost the same. The cause for this difference is also discussed. (semiconductor devices)

  3. SEMICONDUCTOR DEVICES Parallel readout of two-element CdZnTe detectors with real-time digital signal processing

    Science.gov (United States)

    Zhubin, Shi; Linjun, Wang; Kaifeng, Qin; Jiahua, Min; Jijun, Zhang; Xiaoyan, Liang; Jian, Huang; Ke, Tang; Yiben, Xia

    2010-12-01

    Readout electronics, especially digital electronics, for two-element CdZnTe (CZT) detectors in parallel are developed. The preliminary results show the detection efficiency of the two-element CZT detectors in parallel with analog electronics is as many as 1.8 and 2.1 times the single ones, and the energy resolution (FWHM) is limited by that of the single one by the means of analog electronics. However, the digital method for signal processing will be sufficiently better by contrast with an analog method especially in energy resolution. The energy resolution by the means of digital electronics can be improved by about 26.67%, compared to that only with analog electronics, while their detection efficiency is almost the same. The cause for this difference is also discussed.

  4. Novel ZnO:Al contacts to CdZnTe for X- and gamma-ray detectors.

    Science.gov (United States)

    Roy, U N; Mundle, R M; Camarda, G S; Cui, Y; Gul, R; Hossain, A; Yang, G; Pradhan, A K; James, R B

    2016-05-24

    CdZnTe (CZT) has made a significant impact as a material for room-temperature nuclear-radiation detectors due to its potential impact in applications related to nonproliferation, homeland security, medical imaging, and gamma-ray telescopes. In all such applications, common metals, such as gold, platinum and indium, have been used as electrodes for fabricating the detectors. Because of the large mismatch in the thermal-expansion coefficient between the metal contacts and CZT, the contacts can undergo stress and mechanical degradation, which is the main cause for device instability over the long term. Here, we report for the first time on our use of Al-doped ZnO as the preferred electrode for such detectors. The material was selected because of its better contact properties compared to those of the metals commonly used today. Comparisons were conducted for the detector properties using different contacts, and improvements in the performances of ZnO:Al-coated detectors are described in this paper. These studies show that Al:ZnO contacts to CZT radiation detectors offer the potential of becoming a transformative replacement for the common metallic contacts due to the dramatic improvements in the performance of detectors and improved long-term stability.

  5. Gamma spectrometric characterization of short cooling time nuclear spent fuels using hemispheric CdZnTe detectors

    CERN Document Server

    Lebrun, A; Szabó, J L; Arenas-Carrasco, J; Arlt, R; Dubreuil, A; Esmailpur-Kazerouni, K

    2000-01-01

    After years of cooling, nuclear spent fuel gamma emissions are mainly due to caesium isotopes which are emitters at 605, 662 and 796-801 keV. Extensive work has been done on such fuels using various CdTe or CdZnTe probes. When fuels have to be measured after short cooling time (during NPP outage) the spectrum is much more complex due to the important contributions of niobium and zirconium in the 700 keV range. For the first time in a nuclear power plant, four spent fuels of the Kozloduy VVER reactor no 4 were measured during outage, 37 days after shutdown of the reactor. In such conditions, good resolution is of particular interest, so a 20 mm sup 3 hemispheric crystal was used with a resolution better than 7 keV at 662 keV. This paper presents the experimental device and analyzes the results which show that CdZnTe commercially available detectors enabled us to perform a semi-quantitative determination of the burn-up after a short cooling time. In addition, it is discussed how a burn-up evolution code (CESAR)...

  6. Performance comparison of small-pixel CdZnTe radiation detectors with gold contacts formed by sputter and electroless deposition

    Science.gov (United States)

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

    2017-06-01

    Recent improvements in the growth of wide-bandgap semiconductors, such as cadmium zinc telluride (CdZnTe or CZT), has enabled spectroscopic X/γ-ray imaging detectors to be developed. These detectors have applications covering homeland security, industrial analysis, space science and medical imaging. At the Rutherford Appleton Laboratory (RAL) a promising range of spectroscopic, position sensitive, small-pixel Cd(Zn)Te detectors have been developed. The challenge now is to improve the quality of metal contacts on CdZnTe in order to meet the demanding energy and spatial resolution requirements of these applications. The choice of metal deposition method and fabrication process are of fundamental importance. Presented is a comparison of two CdZnTe detectors with contacts formed by sputter and electroless deposition. The detectors were fabricated with a 74 × 74 array of 200 μm pixels on a 250 μm pitch and bump-bonded to the HEXITEC ASIC. The X/γ-ray emissions from an 241Am source were measured to form energy spectra for comparison. It was found that the detector with contacts formed by electroless deposition produced the best uniformity and energy resolution; the best pixel produced a FWHM of 560 eV at 59.54 keV and 50% of pixels produced a FWHM better than 1.7 keV . This compared with a FWHM of 1.5 keV for the best pixel and 50% of pixels better than 4.4 keV for the detector with sputtered contacts.

  7. Design and performances of a low-noise and radiation-hardened readout ASIC for CdZnTe detectors

    Science.gov (United States)

    Bo, Gan; Tingcun, Wei; Wu, Gao; Yongcai, Hu

    2016-06-01

    In this paper, we present the design and performances of a low-noise and radiation-hardened front-end readout application specific integrated circuit (ASIC) dedicated to CdZnTe detectors for a hard X-ray imager in space applications. The readout channel is comprised of a charge sensitive amplifier, a CR-RC shaping amplifier, an analog output buffer, a fast shaper, and a discriminator. An 8-channel prototype ASIC is designed and fabricated in TSMC 0.35-μm mixed-signal CMOS technology, the die size of the prototype chip is 2.2 × 2.2 mm2. The input energy range is from 5 to 350 keV. For this 8-channel prototype ASIC, the measured electrical characteristics are as follows: the overall gain of the readout channel is 210 V/pC, the linearity error is less than 2%, the crosstalk is less than 0.36%, The equivalent noise charge of a typical channel is 52.9 e- at zero farad plus 8.2 e- per picofarad, and the power consumption is less than 2.4 mW/channel. Through the measurement together with a CdZnTe detector, the energy resolution is 5.9% at the 59.5-keV line under the irradiation of the radioactive source 241Am. The radiation effect experiments show that the proposed ASIC can resist the total ionization dose (TID) irradiation of higher than 200 krad(Si). Project supported by the National Key Scientific Instrument and Equipment Development Project (No. 2011YQ040082), the National Natural Science Foundation of China (Nos. 11475136, 11575144, 61176094), and the Shaanxi Natural Science Foundation of China (No. 2015JM1016).

  8. Using the TOF method to measure the electron lifetime in long-drift CdZnTe detectors (Conference Presentation)

    Science.gov (United States)

    Bolotnikov, Aleksey E.; Camarda, Giuseppe S.; Chen, Eric; Cui, Yonggang; Gul, Rubi; Dedic, Václav; De Geronimo, Gianluigi; Fried, Jack; Hossain, Anwar; MacKenzie, Jason M.; Sellin, Paul; Taherion, Saeid; Vernon, Emerson; Yang, Ge; El-hanany, Uri; James, Ralph B.

    2016-09-01

    The traditional method for electron lifetime measurements of CdZnTe (CZT) detectors relies on using the Hecht equation. The procedure involves measuring the dependence of the detector response on the applied bias and applying the Hecht equation to evaluate the mu-tau product, which in turn can be converted into the carrier lifetime if the mobility is known. Despite general acceptance of this technique, which is very convenient for comparative testing of different CZT materials, the assumption of a constant electric field inside a detector is unjustified. In the Hecht equation, this assumption means that the drift time would be a linear function of the drift distance. This condition is rarely fulfilled in practice at low applied biases where the Hecht equation is most sensitive to the mu-tau product. As a result, researchers usually take measurements at relatively high biases, which work well in the case of the low mu-tau material, Technologies. The TOF-based techniques are traditionally used for monitoring the electronegative impurity concentrations in noble gas detectors by measuring the electron lifetimes. We found the electron mu-tau product of tested crystals is in the range 0.1-0.2 cm2/V, which is an order of the magnitude higher than any value previously reported for CZT material. In this work, we reported the measurement procedure and the results. We will also discuss the applicability criteria of the Hecht equation for measuring the electron lifetime in high mu-tau product CZT.

  9. Point Defects in Pb-, Bi-, and In-Doped CdZnTe Detectors:Deep-Level Transient Spectroscopy (DLTS) Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov A.; GUL, R.; KEETER, K.; RODRIGUEZ, R.; BOLOTNIKOV, A.E.; HOSSAIN, A.; CAMARDA, G.S.; KIM, K.H.; YANG, Y.; CUI, Y.; CARCELEN, V.; FRANC, J.; LI, Z.; JAMES, R.B.

    2012-02-29

    We studied, by current deep-level transient spectroscopy (I-DLTS), point defects induced in CdZnTe detectors by three dopants: Pb, Bi, and In. Pb-doped CdZnTe detectors have a new acceptor trap at around 0.48 eV. The absence of a V{sub Cd} trap suggests that all Cd vacancies are compensated by Pb interstitials after they form a deep-acceptor complex [[Pb{sub Cd}]{sup +}-V{sub Cd}{sup 2-}]{sup -}. Bi-doped CdZnTe detectors had two distinct traps: a shallow trap at around 36 meV and a deep donor trap at around 0.82 eV. In detectors doped with In, we noted three well-known traps: two acceptor levels at around 0.18 eV (A-centers) and 0.31 eV (V{sub Cd}), and a deep trap at around 1.1 eV.

  10. Internal electric-field-lines distribution in CdZnTe detectors measured using X-ray mapping

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov,A.E.; , .; Camarda, G.S.; Cui, Y.; Hossain, A.; Yang, G.; Yao, H.W.; James, R.B.

    2009-10-19

    The ideal operation of CdZnTe devices entails having a uniformly distributed internal electric field. Such uniformity especially is critical for thick long-drift-length detectors, such as large-volume CPG and 3-D multi-pixel devices. Using a high-spatial resolution X-ray mapping technique, we investigated the distribution of the electric field in real devices. Our measurements demonstrate that in thin detectors, <5 mm, the electric field-lines tend to bend away from the side surfaces (i.e., a focusing effect). In thick detectors, >1 cm, with a large aspect ratio (thickness-to-width ratio), we observed two effects: the electric field lines bending away from or towards the side surfaces, which we called, respectively, the focusing field-line distribution and the defocusing field-line distribution. In addition to these large-scale variations, the field-line distributions were locally perturbed by the presence of extended defects and residual strains existing inside the crystals. We present our data clearly demonstrating the non-uniformity of the internal electric field.

  11. Performance of a CdZnTe Radiation Detector Grown by a Low-pressure Bridgman Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Soo; Ha, Jang Ho; Lee, Kyu Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-11-15

    CdZnTe (CZT) has been studied for many years as a material for room-temperature, high energy resolution gamma-ray detectors. Currently, prototypical detectors are now available for medical imaging, industrial tomograph and astrophysics in the world-wide. For this reason and next-generation gamma-ray detector, core-technology of CZT crystal growth and detector fabrication is much more crucial. CZT crystal was grown by Low-pressure Bridgman Method at Korea Atomic Energy Research Institute (KAERI) for room-temperature gamma-ray detector. In this study, performance of a CZT radiation detector such as I-V curve and energy resolution for gamma-ray was presented. We measured the I-V curve to define the resistivity of the grown CZT crystal. The electrometer, Keithley 6517A, was used to biasthe high voltage on the detector and read the leakage current. The measured I-V curve is shown in Fig. 3. Resistivity of the planar-type CZT detector, which didn't apply any passivation, was 7.8 x 10{sup 9} Ω·cm. The pulse height spectra was obtained with a CREMAT® CR-110 preamplifier, ORTEC® 572 amplifier, and 919 MCA. Figure 4 and 5 shows the pulse height spectra for 511 keV and 660 keV gamma-ray. The 10.0 % and 9.7 % energy resolutions for 511 keV and 662 keV gamma-ray, respectively, were obtained with the fabricated CZT detector. CZT single crystal was grown by low-pressure Bridgman method. Large domain of (1,1,1) crystalline face was obtained. Resistivity of 7.8 x 10{sup 9} Ω·cm of the grown CZT crystal, can be fabricated gamma-ray detector from the results. 10.0 % and 9.7 % of enrgy resolution for 511 keV and 662 keV gamma-ray, respectively, was also obtained. In the future work, passivation and types of detector, such as a Schottky-type, a Frisch Collor, and a coplanar electrode, will be studied to improve energy resolution.

  12. Preliminary test results of a new high-energy-resolution silicon and CdZnTe pixel detectors for application to x-ray astronomy

    Science.gov (United States)

    Sushkov, V. V.; Hamilton, William J.; Hurley, Kevin; Maeding, Dale G.; Ogelman, Hakki; Paulos, Robert J.; Puetter, Richard C.; Tumer, Tumay O.; Zweerink, Jeffrey

    1999-10-01

    New, high spatial resolution CdZnTe (CZT) and silicon (Si) pixel detectors are highly suitable for x-ray astronomy. These detectors are planned for use in wide field of view, imaging x-ray, and low energy gamma-ray all-sky monitor (AXGAM) in a future space mission. The high stopping power of CZT detectors combined with low-noise front-end readout makes possible an order of magnitude improvement in spatial and energy resolution in x-ray detection. The AXGAM instrument will be built in the form of a fine coded aperture placed over two-dimensional, high spatial resolution and low energy threshold CZT pixel detector array. The preliminary result of CZT and silicon pixel detector test with low-noise readout electronics system are presented. These detectors may also be used with or without modification for medical and industrial imaging.

  13. A multi-technique characterization of electroless gold contacts on single crystal CdZnTe radiation detectors

    OpenAIRE

    Bell, S J; BAKER, M.A.; Chen, H.; Marthandam, P; V. Perumal; A. Schneider; Seller, P.; Sellin, P J; Veale, M C; Wilson, M. D.

    2013-01-01

    Cadmium zinc telluride (CdZnTe) is now established as a popular choice of sensor for the detection of γ-rays and hard x-rays, leading to its adoption in security, medical and scientific applications. There are still many technical challenges involving the deposition of high-quality, uniform metal contacts on CdZnTe. A detailed understanding of the interface between the bulk CdZnTe and the metal contacts is required for improvements to be made. To understand these complex interfaces, a range o...

  14. Development of new CdZnTe detectors for room-temperature high-flux radiation measurements.

    Science.gov (United States)

    Abbene, Leonardo; Gerardi, Gaetano; Raso, Giuseppe; Principato, Fabio; Zambelli, Nicola; Benassi, Giacomo; Bettelli, Manuele; Zappettini, Andrea

    2017-03-01

    Recently, CdZnTe (CZT) detectors have been widely proposed and developed for room-temperature X-ray spectroscopy even at high fluxes, and great efforts have been made on both the device and the crystal growth technologies. In this work, the performance of new travelling-heater-method (THM)-grown CZT detectors, recently developed at IMEM-CNR Parma, Italy, is presented. Thick planar detectors (3 mm thick) with gold electroless contacts were realised, with a planar cathode covering the detector surface (4.1 mm × 4.1 mm) and a central anode (2 mm × 2 mm) surrounded by a guard-ring electrode. The detectors, characterized by low leakage currents at room temperature (4.7 nA cm(-2) at 1000 V cm(-1)), allow good room-temperature operation even at high bias voltages (>7000 V cm(-1)). At low rates (200 counts s(-1)), the detectors exhibit an energy resolution around 4% FWHM at 59.5 keV ((241)Am source) up to 2200 V, by using commercial front-end electronics (A250F/NF charge-sensitive preamplifier, Amptek, USA; nominal equivalent noise charge of 100 electrons RMS). At high rates (1 Mcounts s(-1)), the detectors, coupled to a custom-designed digital pulse processing electronics developed at DiFC of University of Palermo (Italy), show low spectroscopic degradations: energy resolution values of 8% and 9.7% FWHM at 59.5 keV ((241)Am source) were measured, with throughputs of 0.4% and 60% at 1 Mcounts s(-1), respectively. An energy resolution of 7.7% FWHM at 122.1 keV ((57)Co source) with a throughput of 50% was obtained at 550 kcounts s(-1) (energy resolution of 3.2% at low rate). These activities are in the framework of an Italian research project on the development of energy-resolved photon-counting systems for high-flux energy-resolved X-ray imaging.

  15. A 12-bit 1 MS/s SAR-ADC for multi-channel CdZnTe detectors

    Science.gov (United States)

    Wei, Liu; Tingcun, Wei; Bo, Li; Panjie, Guo; Yongcai, Hu

    2015-04-01

    This paper presents a low power, area-efficient and radiation-hardened 12-bit 1 MS/s successive approximation register (SAR) analog-to-digital converter (ADC) for multi-channel CdZnTe (CZT) detector applications. In order to improve the SAR-ADC's accuracy, a novel comparator is proposed in which the offset voltage is self-calibrated and also a new architecture for the unit capacitor array is proposed to reduce the capacitance mismatches in the charge-redistribution DAC. The ability to radiation-harden the SAR-ADC is enhanced through circuit and layout design technologies. The prototype chip was fabricated using a TSMC 0.35 μm 2P4M CMOS process. At a 3.3/5 V power supply and a sampling rate of 1 MS/s, the proposed SAR-ADC achieves a peak signal to noise and distortion ratio (SINAD) of 67.64 dB and consumes only 10 mW power. The core of the prototype chip occupies an active area of 1180 × 1080 μm2. Project supported by the Special-Funded Program on National Key Scientific Instruments and Equipment Development (No. 2011YQ040082).

  16. Improving performance of a CdZnTe imaging array by mapping the detector with gamma rays

    CERN Document Server

    Marks, D G; Barrett, H H; Tüller, J; Woolfenden, J M

    1999-01-01

    We can greatly reduce image artifacts in our pixellated CdZnTe arrays by mapping imperfect regions with a narrow collimated beam of gamma rays. Portions of our detectors produce signals that agree well with simulations of gamma-ray interactions, but there are many examples of structures in the material that respond unpredictably to gamma rays. We mapped some of these imperfect regions using 60 and 140 keV gamma-ray beams, recording a 7x7 set of pixel signals for each interaction. The pixel pitch was 380 mu m. We used the mapped data to estimate the probability density function (PDF) of the pixel signals for each interaction position. Images were taken on the mapped sections, storing each gamma ray as a list of pixel signals. Images could be formed by either estimating each gamma-ray interaction position individually or using the entire set of image data in a single iterative computation using the expectation-maximization (EM) algorithm. At 60 keV individual interaction positions were estimated by fitting the ...

  17. Development of CdZnTe X-ray detectors at DSRI

    DEFF Research Database (Denmark)

    van Pamelen, M.A.J.; Budtz-Jørgensen, Carl; Kuvvetli, Irfan

    2000-01-01

    at DSRI. With the advent of the Danish Micro Satellite program it was, however, recognised that this type of detector is very well suited for two proposed missions (eXCALIBur, AXO). The research at DSRI has so far been concentrated on the spectroscopic properties of the CZT detector. At DSRI we have...

  18. Optimal configuration of a low-dose breast-specific gamma camera based on semiconductor CdZnTe pixelated detectors

    Science.gov (United States)

    Genocchi, B.; Pickford Scienti, O.; Darambara, DG

    2017-05-01

    Breast cancer is one of the most frequent tumours in women. During the ‘90s, the introduction of screening programmes allowed the detection of cancer before the palpable stage, reducing its mortality up to 50%. About 50% of the women aged between 30 and 50 years present dense breast parenchyma. This percentage decreases to 30% for women between 50 to 80 years. In these women, mammography has a sensitivity of around 30%, and small tumours are covered by the dense parenchyma and missed in the mammogram. Interestingly, breast-specific gamma-cameras based on semiconductor CdZnTe detectors have shown to be of great interest to early diagnosis. Infact, due to the high energy, spatial resolution, and high sensitivity of CdZnTe, molecular breast imaging has been shown to have a sensitivity of about 90% independently of the breast parenchyma. The aim of this work is to determine the optimal combination of the detector pixel size, hole shape, and collimator material in a low dose dual head breast specific gamma camera based on a CdZnTe pixelated detector at 140 keV, in order to achieve high count rate, and the best possible image spatial resolution. The optimal combination has been studied by modeling the system using the Monte Carlo code GATE. Six different pixel sizes from 0.85 mm to 1.6 mm, two hole shapes, hexagonal and square, and two different collimator materials, lead and tungsten were considered. It was demonstrated that the camera achieved higher count rates, and better signal-to-noise ratio when equipped with square hole, and large pixels (> 1.3 mm). In these configurations, the spatial resolution was worse than using small pixel sizes (< 1.3 mm), but remained under 3.6 mm in all cases.

  19. Defect Measurements of CdZnTe Detectors Using I-DLTS, TCT, I-V and Gamma-ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gul,R.

    2008-08-11

    In this work we measured the crystal defect levels and tested the performance of CdZnTe detectors by diverse methodologies, viz., Current Deep Level Transient Spectroscopy (I-DLTS), Transient Current Technique (TCT), Current and Capacitance versus Voltage measurements (I-V and C-V), and gamma-ray spectroscopy. Two important characteristics of I-DLTS technique for advancing this research are (1) it is applicable for high-resistivity materials (>10{sup 6} {Omega}-cm), and, (2) the minimum temperature for measurements can be as low as 10 K. Such low-temperature capability is excellent for obtaining measurements at shallow levels. We acquired CdZnTe crystals grown by different techniques from two different vendors and characterized them for point defects and their response to photons. I-DLTS studies encompassed measuring the parameters of the defects, such as the energy levels in the band gap, the carrier capture cross-sections and their densities. The current induced by the laser-generated carriers and the charge collected (or number of electrons collected) were obtained using TCT that also provides the transport properties, such as the carrier life time and mobility of the detectors under study. The detector's electrical characteristics were explored, and its performance tested using I-V, C-V and gamma-ray spectroscopy.

  20. Defect measurements of CdZnTe detectors using I-DLTS, TCT, I-V, C-V and γ-ray spectroscopy

    Science.gov (United States)

    Gul, R.; Li, Z.; Rodriguez, R.; Keeter, K.; Bolotnikov, A.; James, R.

    2008-08-01

    In this work we measured the crystal defect levels and tested the performance of CdZnTe detectors by diverse methodologies, viz., Current Deep Level Transient Spectroscopy (I-DLTS), Transient Current Technique (TCT), Current and Capacitance versus Voltage measurements (I-V and C-V), and gamma-ray spectroscopy. Two important characteristics of I-DLTS technique for advancing this research are (1) it is applicable for high-resistivity materials (>106 Ω-cm), and, (2) the minimum temperature for measurements can be as low as 10 K. Such low-temperature capability is excellent for obtaining measurements at shallow levels. We acquired CdZnTe crystals grown by different techniques from two different vendors and characterized them for point defects and their response to photons. I-DLTS studies encompassed measuring the parameters of the defects, such as the energy levels in the band gap, the carrier capture cross-sections and their densities. The current induced by the laser-generated carriers and the charge collected (or number of electrons collected) were obtained using TCT that also provides the transport properties, such as the carrier life time and mobility of the detectors under study. The detector's electrical characteristics were explored, and its performance tested using I-V, C-V and gamma-ray spectroscopy.

  1. Electrode Design of Cylindrical Coplanar-grid CdZnTe Detector by Finite Element Methods

    Institute of Scientific and Technical Information of China (English)

    JIN Wei; SANG Wen-bin; ZHANG Qi; MIN Jia-Hua; SHEN Yan

    2004-01-01

    Cylindrical coplanar- grid configurations, which offer a lot of advantages over established designs,can effectively overcome the problem of poor hole collection. Finite element analysis is utilized for simulating the potential distribution of the cylindrical coplanar-grid detector under different models by varying the widths of grid and pitch of electrodes. In addition, a modified grid pattern has been discussed to improve the weighting potential match between two grids. In this way, the geometry of electrodes for cylindrical coplanar- grid detectors is optimized.

  2. Effects of bulk and surface conductivity on the performance of CdZnTe pixel detectors

    DEFF Research Database (Denmark)

    Bolotnikov, A.E.; Chen, C.M.H.; Cook, W.R.;

    2002-01-01

    between the pixel contacts. When the grid is negatively biased, the strong electric field in the gaps between the pixels forces the electrons landing on the surface to move toward the contacts, preventing the charge loss. We have investigated these effects by using CZT pixel detectors indium bump...

  3. Measurement of Uranium Enrichment by Using CdZnTe Detector

    Institute of Scientific and Technical Information of China (English)

    XU; Zheng; LU; Wen-guang; CHENG; Yi-mei; YIN; Hong-he

    2015-01-01

    Uranium enrichment measurement method uses the intensity of the 235U 186keV gamma ray to determine the enrichment of samples.If the uranium sample is large enough,the 186keV gamma rays from only a fraction volume of the total sample can reach the detector because of the

  4. CdZnTe detector for computed tomography based on weighting potential

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyun Jong; Park, Chan Sun; Kim, Jung Su; Kim, Jung Min; Choi, Jong Hak; Kim, Ki Hyun [Korea University, Seoul (Korea, Republic of)

    2016-03-15

    Room-temperature operating CdZnTe(CZT) material is an innovative radiation detector which could reduce the patient dose to one-tenth level of conventional CT (Computed Tomography) and mammography system. The pixel and pixel pitch in the imaging device determine the conversion efficiency of incident Xor gamma-ray and the cross-talk of signal, that is, image quality of detector system. The weighting potential is the virtual potential determined by the position and geometry of electrode. The weighting potential obtained by computer-based simulation in solving Poisson equation with proper boundaries condition. The pixel was optimized by considering the CIE (charge induced efficiency) and the signal cross-talk in CT detector system. The pixel pitch was 1-mm and the detector thickness was 2-mm in the simulation. The optimized pixel size and inter-pixel distance for maximizing the CIE and minimizing the signal cross-talk is about 750 μm and 125 μm, respectively.

  5. CdTe and CdZnTe detectors in nuclear medicine

    CERN Document Server

    Scheiber, C

    2000-01-01

    Nuclear medicine diagnostic applications are growing in search for more disease specific or more physiologically relevant imaging. The data are obtained non-invasively from large field gamma cameras or from miniaturised probes. As far as single photon emitters are concerned, often labelled with sup 9 sup 9 sup m Tc (140 keV, gamma), nuclear instrumentation deals with poor counting statistics due to the method of spatial localisation and low contrast to noise due to scatter in the body. Since the 1960s attempts have been made to replace the NaI scintillator by semiconductor detectors with better spectrometric characteristics to improve contrast and quantitative measurements. They allow direct conversion of energy and thus more compact sensors. Room-temperature semiconductor detectors such as cadmium tellure and cadmium zinc tellure have favourable physical characteristics for medical applications which have been investigated in the 1980s. During one decade, they have been used in miniaturised probes such as fo...

  6. Characterization of charge carrier collection in a CdZnTe Frisch collar detector with a highly collimated {sup 137}Cs source

    Energy Technology Data Exchange (ETDEWEB)

    Kargar, Alireza [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Harrison, Mark J. [Nuclear and Radiological Engineering, University of Florida, 202 NSB, Gainesville, FL 32611 (United States); Brooks, Adam C. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S., E-mail: mcgregor@ksu.ed [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2010-08-21

    A 4.7 x4.7x9.5 mm{sup 3} CdZnTe Frisch collar device was characterized through probing the device with a highly collimated {sup 137}Cs 662 keV gamma ray source. In a systematic series of experiments, the detector was probed along the length and width with a {sup 137}Cs gamma ray source using a 43.0 mm long Pb-collimator with a 0.6 mm circular hole. The detector was probed along the central line under different operating voltages of 1200, 1000, 800, 600 and 400 V. The experimental results correlated well to charge collection calculations for a modeled device with the same size and operating conditions. It was proved that, unlike the planar configuration, the charge collection efficiency profile along the length of Frisch collar device is considerably improved. The CdZnTe raw materials for this study were acquired from Redlen Technologies, and the Frisch collar device was fabricated and characterized at S.M.A.R.T. Laboratory at Kansas State University.

  7. Material-specific imaging system using energy-dispersive X-ray diffraction and spatially resolved CdZnTe detectors with potential application in breast imaging

    Science.gov (United States)

    Barbes, Damien; Tabary, Joachim; Paulus, Caroline; Hazemann, Jean-Louis; Verger, Loïck

    2017-03-01

    This paper presents a coherent X-ray-scattering imaging technique using a multipixel energy-dispersive system. Without any translation, the technique produces specific 1D image from data recorded by a single CdZnTe detector pixel using subpixelation techniques. The method is described in detail, illustrated by a simulation and then experimentally validated. As the main considered application of our study is breast imaging, this validation involves 2D imaging of a phantom made of plastics mimicking breast tissues. The results obtained show that our system can specifically image the phantom using a single detector pixel. For the moment, in vivo breast imaging applications remain difficult, as the dose delivered by the system is too high, but some adjustments are considered for further work.

  8. Final Report: A CdZnTe detector for MRI-compatible SPECT Systems

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Ling-Jian

    2012-12-27

    The key objective of this project is to develop the enabling technology for future MRI-compatible nuclear (e.g. SPECT) imaging system, and to demonstrate the feasibility of performing simultaneous MR and SPECT imaging studies of the same object. During the past three years, we have developed (a) a MRI-compatible ultrahigh resolution gamma ray detector and associated readout electronics, (b) a theoretical approach for modeling the effect of strong magnetic field on SPECT image quality, and (c) a maximum-likelihood (ML) based reconstruction routine with correction for the MR-induced distortion. With this support, we have also constructed a four-head MR-compatible SPECT system and tested the system inside a 3-T clinical MR-scanner located on UI campus. The experimental results obtained with this system have clearly demonstrated that sub-500um spatial resolution can be achieved with a SPECT system operated inside a 3-T MRI scanner. During the past three years, we have accomplished most of the major objectives outlined in the original proposal. These research efforts have laid out a solid foundation the development of future MR-compatible SPECT systems for both pre-clinical and clinical imaging applications.

  9. Dynamics of native oxide growth on CdTe and CdZnTe X-ray and gamma-ray detectors

    Science.gov (United States)

    Zázvorka, Jakub; Franc, Jan; Beran, Lukáš; Moravec, Pavel; Pekárek, Jakub; Veis, Martin

    2016-01-01

    Abstract We studied the growth of the surface oxide layer on four different CdTe and CdZnTe X-ray and gamma-ray detector-grade samples using spectroscopic ellipsometry. We observed gradual oxidization of CdTe and CdZnTe after chemical etching in bromine solutions. From X-ray photoelectron spectroscopy measurements, we found that the oxide consists only of oxygen bound to tellurium. We applied a refined theoretical model of the surface layer to evaluate the spectroscopic ellipsometry measurements. In this way we studied the dynamics and growth rate of the oxide layer within a month after chemical etching of the samples. We observed two phases in the evolution of the oxide layer on all studied samples. A rapid growth was visible within five days after the chemical treatment followed by semi-saturation and a decrease in the growth rate after the first week. After one month all the samples showed an oxide layer about 3 nm thick. The oxide thickness was correlated with leakage current degradation with time after surface preparation. PMID:27933118

  10. Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

    CERN Document Server

    Troyer, G L

    2000-01-01

    High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse r...

  11. Investigation of CdZnTe and LiNbO{sub 3} as electro-optic neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A.; Edwards, Nathan [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506 (United States); Harrison, Mark J. [Nuclear and Radiological Engineering, University of Florida, 202 NSB, Gainesville, FL 32611 (United States); Kargar, Alireza; McNeil, Walter J. [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506 (United States); Rojeski, Ronald A. [Cymer, Inc., San Diego, CA 92127 (United States); McGregor, Douglas S., E-mail: mcgregor@ksu.ed [S.M.A.R.T. Laboratory, Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506 (United States)

    2010-08-21

    An alternative method for the detection of thermal neutrons has been investigated utilizing the Pockels effect with CdZnTe and LiNbO{sub 3}. A photodiode was used to indicate a change in light intensity transmitted through an assembly consisting of polarizer, Pockels cell, and analyzer. Ionization due to neutron reaction products can perturb an established electric field within the cell, thus changing the transmitted light intensity through the assembly. The CdZnTe cell demonstrated a repeatable change in transmitted light intensity, increasing with neutron flux, marking the first recorded use of this technology to detect neutrons. However, the LiNbO{sub 3} cell gave no response to neutron irradiation, and is assumed to be a result of the extremely short carrier lifetimes found in the material.

  12. Use of the drift-time method to measure the electron lifetime in long-drift-length CdZnTe detectors

    Science.gov (United States)

    Bolotnikov, A. E.; Camarda, G. S.; Chen, E.; Gul, R.; Dedic, V.; De Geronimo, G.; Fried, J.; Hossain, A.; MacKenzie, J. M.; Ocampo, L.; Sellin, P.; Taherion, S.; Vernon, E.; Yang, G.; El-Hanany, U.; James, R. B.

    2016-09-01

    The traditional method for electron lifetime measurements of CdZnTe (CZT) detectors relies on using the Hecht equation. The procedure involves measuring the dependence of the detector response on the applied bias to evaluate the μτ product, which in turn can be converted into the carrier lifetime. Despite general acceptance of this technique, which is very convenient for comparative testing of different CZT materials, the assumption of a constant electric field inside a detector is unjustified. In the Hecht equation, this assumption means that the drift time would be a linear function of the distance. This condition is not fulfilled in practice at low applied biases, where the Hecht equation is most sensitive to the μτ product. As a result, researchers usually take measurements at relatively high biases, which work well in the case of the low μτ-product material, grade CZT detectors produced by the Redlen Technologies. We found that the electron μτ product of tested crystals is in the range 0.1-0.2 cm2/V, which is an order of the magnitude higher than any value previously reported for a CZT material. In comparison, using the Hecht equation fitting, we obtained μτ = 2.3 × 10-2 cm2/V for a 2-mm thin planar detector fabricated from the same CZT material.

  13. Synchrotron radiation studies of spectral response features caused by Te inclusions in a large volume coplanar grid CdZnTe detector

    CERN Document Server

    Hansson, Conny C T; Quarati, Francesco; Kozorezov, Alexander; Gostilo, Vladimir; Lumb, David

    2011-01-01

    We report preliminary results from a synchrotron radiation study of Te inclusions in a large volume single crystal CdZnTe (CZT) coplanar-grid detector. The experiment was carried out by probing individual inclusions with highly collimated monochromatic X-and gamma-ray beams. It was found that for shallow X-ray interaction depths, the effect of an inclusion on measured energy loss spectra is to introduce a ~10% shift in the peak centroid energy towards lower channel numbers. The total efficiency is however not affected, showing that the net result of inclusions is a reduction in the Charge Collection Efficiency (CCE). For deeper interaction depths, the energy-loss spectra shows the emergence of two distinct peaks, both downshifted in channel number. We note that the observed spectral behavior shows strong similarities with that reported in semiconductors which exhibit polarization effects, suggesting that the underlying mechanism is common.

  14. Linearity enhancement design of a 16-channel low-noise front-end readout ASIC for CdZnTe detectors

    Science.gov (United States)

    Zeng, Huiming; Wei, Tingcun; Wang, Jia

    2017-03-01

    A 16-channel front-end readout application-specific integrated circuit (ASIC) with linearity enhancement design for cadmium zinc telluride (CdZnTe) detectors is presented in this paper. The resistors in the slow shaper are realized using a high-Z circuit to obtain constant resistance value instead of using only a metal-oxide-semiconductor (MOS) transistor, thus the shaping time of the slow shaper can be kept constant for different amounts of input energies. As a result, the linearity of conversion gain is improved significantly. The ASIC was designed and fabricated in a 0.35 μm CMOS process with a die size of 2.60 mm×3.53 mm. The tested results show that a typical channel provides an equivalent noise charge (ENC) of 109.7e-+16.3e-/pF with a power consumption of 4 mW and achieves a conversion gain of 87 mV/fC with a nonlinearity of <0.4%. The linearity of conversion gain is improved by at least 86.6% as compared with the traditional approaches using the same front-end readout architecture and manufacture process. Moreover, the inconsistency among channels is <0.3%. An energy resolution of 2.975 keV (FWHM) for gamma rays of 59.5 keV was measured by connecting the ASIC to a 5 mm×5 mm ×2 mm CdZnTe detector at room temperature. The front-end readout ASIC presented in this paper achieves an outstanding linearity performance without compromising the noise, power consumption, and chip size performances.

  15. Performance simulation of an x-ray detector for spectral CT with combined Si and Cd[Zn]Te detection layers.

    Science.gov (United States)

    Herrmann, Christoph; Engel, Klaus-Jürgen; Wiegert, Jens

    2010-12-21

    The most obvious problem in obtaining spectral information with energy-resolving photon counting detectors in clinical computed tomography (CT) is the huge x-ray flux present in conventional CT systems. At high tube voltages (e.g. 140 kVp), despite the beam shaper, this flux can be close to 10⁹ Mcps mm⁻² in the direct beam or in regions behind the object, which are close to the direct beam. Without accepting the drawbacks of truncated reconstruction, i.e. estimating missing direct-beam projection data, a photon-counting energy-resolving detector has to be able to deal with such high count rates. Sub-structuring pixels into sub-pixels is not enough to reduce the count rate per pixel to values that today's direct converting Cd[Zn]Te material can cope with (≤ 10 Mcps in an optimistic view). Below 300 µm pixel pitch, x-ray cross-talk (Compton scatter and K-escape) and the effect of charge diffusion between pixels are problematic. By organising the detector in several different layers, the count rate can be further reduced. However this alone does not limit the count rates to the required level, since the high stopping power of the material becomes a disadvantage in the layered approach: a simple absorption calculation for 300 µm pixel pitch shows that the required layer thickness of below 10 Mcps/pixel for the top layers in the direct beam is significantly below 100 µm. In a horizontal multi-layer detector, such thin layers are very difficult to manufacture due to the brittleness of Cd[Zn]Te. In a vertical configuration (also called edge-on illumination (Ludqvist et al 2001 IEEE Trans. Nucl. Sci. 48 1530-6, Roessl et al 2008 IEEE NSS-MIC-RTSD 2008, Conf. Rec. Talk NM2-3)), bonding of the readout electronics (with pixel pitches below 100 µm) is not straightforward although it has already been done successfully (Pellegrini et al 2004 IEEE NSS MIC 2004 pp 2104-9). Obviously, for the top detector layers, materials with lower stopping power would be advantageous

  16. Study of CdTe:Cl and CdZnTe detectors for medical multi-slices X-ray Computed Tomography; Etude de detecteurs en CdTe:Cl et CdZnTe pour la tomographie X medicale multicoupes

    Energy Technology Data Exchange (ETDEWEB)

    Ricq, St

    1999-09-28

    The application of CdTe and CdZnTe detectors to medical X-ray Computed Tomography have been investigated. Different electrodes (Au, Pt, In) have been deposited on CdZnTe HPBM and on CdTe:ClTHM. Their injection properties have been determined with Current-Voltage characteristics. Under X-ray in CT conditions, injection currents measurements reveal trapped carriers space-charges formation. The same way, the comparisons of the responses to X-beam cut-off with various injection possibilities enable to follow the space-charges evolutions and then to determine the predominant traps types. Nevertheless, both hole and electron traps are responsible for the memory effect e.g. the currents levels dependence with irradiation history. This effect is noticed in particular on responses to fast flux variations that simulate scanner's conditions. Trap levels probably corresponding to native defects are responsible for these limitations. In order to make such detectors suitable for X-ray Computed Tomography, significant progresses in CdTe for CdZnTe crystal growth with an important defects densities reduction (factor 10), or possibly counting mode operation, seem necessary. (author)

  17. Drift time variations in CdZnTe detectors measured with alpha-particles: Their correlation with the detector’s responses

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov A. E.; Butcher, J.; Hamade, M.; Petryk, M.; Bolotnikov, A.; Camarda, G.; Cui, Y.; Hossain, A.; Kim, K.; Yang, G.; and James, R.

    2012-05-14

    Homogeneity of properties related to material crystallinity is a critical parameter for achieving high-performance CdZnTe (CZT) radiation detectors. Unfortunately, this requirement is not always satisfied in today's commercial CZT material due to high concentrations of extended defects, in particular subgrain boundaries, which are believed to be part of the causes hampering the energy resolution and efficiency of CZT detectors. In the past, the effects of subgrain boundaries have been studied in Si, Ge and other semiconductors. It was demonstrated that subgrain boundaries tend to accumulate secondary phases and impurities causing inhomogeneous distributions of trapping centers. It was also demonstrated that subgrain boundaries result in local perturbations of the electric field, which affect the carrier transport and other properties of semiconductor devices. The subgrain boundaries in CZT material likely behave in a similar way, which makes them responsible for variations in the electron drift time and carrier trapping in CZT detectors. In this work, we employed the transient current technique to measure variations in the electron drift time and related the variations to the device performances and subgrain boundaries, whose presence in the crystals were confirmed with white beam X-ray diffraction topography and infrared transmission microscopy.

  18. CMOS low-noise switched charge sensitive preamplifier for CdTe and CdZnTe X-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Jakobson, C.G.; Nemirovsky, Y. [Technion-Israel Inst. of Tech., Haifa (Israel)

    1997-02-01

    CdTe and CdZnTe X-ray detector arrays for imaging and spectroscopy provide low capacitance current sources with low leakage currents. The optimal shaping time for low-noise operation is relatively high in CMOS analog channels that provide the readout for these detectors. The shaper is centered at lower frequencies, and thus the l/f noise from the electronics is the main noise source that limits the resolution of the channel. The optimal dimensions of the input stage MOSFET are determined by this noise. In this paper a design criterion for the optimization of the resolution and the power consumption in a l/f noise dominated readout is introduced. A readout based on CMOS switched charge sensitive preamplifier without feedback resistor has been designed and fabricated in the CMOS 2-{mu} low-noise analog process provided by MOSIS. This design provides high sensitivity and the possibility to integrate a large number of channels with low power consumption. Measurements of the performance of a first prototype chip are presented.

  19. X-ray response of CdZnTe detectors grown by the vertical Bridgman technique: Energy, temperature and high flux effects

    Science.gov (United States)

    Abbene, L.; Gerardi, G.; Turturici, A. A.; Raso, G.; Benassi, G.; Bettelli, M.; Zambelli, N.; Zappettini, A.; Principato, F.

    2016-11-01

    Nowadays, CdZnTe (CZT) is one of the key materials for the development of room temperature X-ray and gamma ray detectors and great efforts have been made on both the device and the crystal growth technologies. In this work, we present the results of spectroscopic investigations on new boron oxide encapsulated vertical Bridgman (B-VB) grown CZT detectors, recently developed at IMEM-CNR Parma, Italy. Several detectors, with the same electrode layout (gold electroless contacts) and different thicknesses (1 and 2.5 mm), were realized: the cathode is a planar electrode covering the detector surface (4.1×4.1 mm2), while the anode is a central electrode (2×2 mm2) surrounded by a guard-ring electrode. The detectors are characterized by electron mobility-lifetime product (μeτe) values ranging between 0.6 and 1·10-3 cm2/V and by low leakage currents at room temperature and at high bias voltages (38 nA/cm2 at 10000 V/cm). The spectroscopic response of the detectors to monochromatic X-ray and gamma ray sources (109Cd, 241Am and 57Co), at different temperatures and fluxes (up to 1 Mcps), was measured taking into account the mitigation of the effects of incomplete charge collection, pile-up and high flux radiation induced polarization phenomena. A custom-designed digital readout electronics, developed at DiFC of University of Palermo (Italy), able to perform a fine pulse shape and height analysis even at high fluxes, was used. At low rates (200 cps) and at room temperature (T=25 °C), the detectors exhibit an energy resolution FWHM around 4% at 59.5 keV, for comparison an energy resolution of 3% was measured with Al/CdTe/Pt detectors by using the same electronics (A250F/NF charge sensitive preamplifier, Amptek, USA; nominal ENC of 100 electrons RMS). At high rates (750 kcps), energy resolution values of 7% and 9% were measured, with throughputs of 2% and 60% respectively. No radiation polarization phenomena were observed at room temperature up to 1 Mcps (241Am source, 60 ke

  20. Long-Term Stable Surface Treatments on CdTe and CdZnTe Radiation Detectors

    Science.gov (United States)

    Pekarek, Jakub; Belas, Eduard; Zazvorka, Jakub

    2017-04-01

    The spectral resolution and charge collection efficiency (CCE) of cadmium telluride (CdTe) and cadmium zinc telluride (CZT) room-temperature x-ray and gamma-ray detectors are often limited by high surface leakage current due to conducting surface species created during detector fabrication. Surface treatments play a major role in reduction of this surface leakage current. The effect of various types of surface etching and passivation on the leakage current and thereby the spectral energy resolution, CCE, and internal electric field profile of CdTe/CZT detectors has been studied. The main aim of this work is preparation of long-term stable detectors with strongly reduced leakage current. The time stability of the current-voltage characteristic and spectral resolution was investigated during 21 days and 1 year, respectively, after performing surface treatments. Our results suggest that the optimal detector preparation method is chemomechanical polishing in bromine-ethylene glycol solution followed by chemical etching in bromine-methanol solution then surface passivation in potassium hydroxide or ammonium fluoride (NH4F/H2O2). Detectors prepared using this optimal treatment exhibited low leakage current, high spectral resolution, and long-term stability compared with those subjected to other surface preparation methods.

  1. Long-Term Stable Surface Treatments on CdTe and CdZnTe Radiation Detectors

    Science.gov (United States)

    Pekarek, Jakub; Belas, Eduard; Zazvorka, Jakub

    2016-12-01

    The spectral resolution and charge collection efficiency (CCE) of cadmium telluride (CdTe) and cadmium zinc telluride (CZT) room-temperature x-ray and gamma-ray detectors are often limited by high surface leakage current due to conducting surface species created during detector fabrication. Surface treatments play a major role in reduction of this surface leakage current. The effect of various types of surface etching and passivation on the leakage current and thereby the spectral energy resolution, CCE, and internal electric field profile of CdTe/CZT detectors has been studied. The main aim of this work is preparation of long-term stable detectors with strongly reduced leakage current. The time stability of the current-voltage characteristic and spectral resolution was investigated during 21 days and 1 year, respectively, after performing surface treatments. Our results suggest that the optimal detector preparation method is chemomechanical polishing in bromine-ethylene glycol solution followed by chemical etching in bromine-methanol solution then surface passivation in potassium hydroxide or ammonium fluoride (NH4F/H2O2). Detectors prepared using this optimal treatment exhibited low leakage current, high spectral resolution, and long-term stability compared with those subjected to other surface preparation methods.

  2. Characterization of CdTe and CdZnTe detectors for gamma-ray imaging applications

    Science.gov (United States)

    Verger, L.; Boitel, M.; Gentet, M. C.; Hamelin, R.; Mestais, C.; Mongellaz, F.; Rustique, J.; Sanchez, G.

    2001-02-01

    CEA-LETI in association with Bicron and Crismatec has been developing solid-state gamma camera technology based on CZT. The project included gamma camera head systems development including front-end electronics with an integrated circuit (ASIC), material growth, and detector fabrication and characterization. One feature of the work is the use of linear correlation between the amplitude and the fast rise time of the signal - which corresponds to the electron transit time in the detector, a development that was reported previously and which allows more than 80% of the 122 keV γ-photons incident on HPBM material to be recovered in a ±6.5% 2D window. In the current work, we summarize other methods to improve CZT detector performance and compare them with the Bi-Parametric Spectrum (BPS) method. The BPS method can also be applied as a diagnositic. BPS curve shapes are shown to vary with electric field, and with electron transport properties, and the correction algorithims are seen to be robust over a range of values. In addition, the technique is found to improve detectors from a variety of sources including some with special electrode geometries. In all cases, the BPS method improves efficiency (>75%) without degrading energy resolution (± 6.5% 2D window) even for a monolithic detector. The method does not overcome bulk inhomogeneity nor noise which comes from low resistivity.

  3. Effect of electron transport properties on unipolar CdZnTe radiation detectors: LUND, SpectrumPlus, and Coplanar Grid

    Energy Technology Data Exchange (ETDEWEB)

    Ralph B. James

    2000-01-07

    Device simulations of (1) the laterally-contacted-unipolar-nuclear detector (LUND), (2) the SpectrumPlus, (3) and the coplanar grid made of Cd{sub 0.9}Zn{sub 0.1}Te (CZT) were performed for {sup 137}Cs irradiation by 662.15 keV gamma-rays. Realistic and controlled simulations of the gamma-ray interactions with the CZT material were done using the MCNP4B2 Monte Carlo program, and the detector responses were simulated using the Sandia three-dimensional multielectrode simulation program (SandTMSP). The simulations were done for the best and the worst expected carrier nobilities and lifetimes of currently commercially available CZT materials for radiation detector applications. For the simulated unipolar devices, the active device volumes were relatively large and the energy resolutions were fairly good, but these performance characteristics were found to be very sensitive to the materials properties. The internal electric fields, the weighting potentials, and the charge induced efficiency maps were calculated to give insights into the operation of these devices.

  4. An analysis of point defects induced by In, Al, Ni, and Sn dopants in Bridgman-grown CdZnTe detectors and their influence on trapping of charge carriers

    Science.gov (United States)

    Gul, R.; Roy, U. N.; James, R. B.

    2017-03-01

    In this research, we studied point defects induced in Bridgman-grown CdZnTe detectors doped with Indium (In), Aluminium (Al), Nickel (Ni), and Tin (Sn). Point defects associated with different dopants were observed, and these defects were analyzed in detail for their contributions to electron/hole (e/h) trapping. We also explored the correlations between the nature and abundance of the point defects with their influence on the resistivity, electron mobility-lifetime (μτe) product, and electron trapping time. We used current-deep level transient spectroscopy to determine the energy, capture cross-section, and concentration of each trap. Furthermore, we used the data to determine the trapping and de-trapping times for the charge carriers. In In-doped CdZnTe detectors, uncompensated Cd vacancies (VCd-) were identified as a dominant trap. The VCd- were almost compensated in detectors doped with Al, Ni, and Sn, in addition to co-doping with In. Dominant traps related to the dopant were found at Ev + 0.36 eV and Ev + 1.1 eV, Ec + 76 meV and Ev + 0.61 eV, Ev + 36 meV and Ev + 0.86 eV, Ev + 0.52 eV and Ec + 0.83 eV in CZT:In, CZT:In + Al, CZT:In + Ni, and CZT:In + Sn, respectively. Results indicate that the addition of other dopants with In affects the type, nature, concentration (Nt), and capture cross-section (σ) and hence trapping (tt) and de-trapping (tdt) times. The dopant-induced traps, their corresponding concentrations, and charge capture cross-section play an important role in the performance of radiation detectors, especially for devices that rely solely on electron transport.

  5. 碲锌镉面元辐射探测器堆积载流子屏蔽效应%Accumulated-carrier screening effect based investigation for pixellated CdZnTe radiation detector

    Institute of Scientific and Technical Information of China (English)

    肖沙里; 黎淼; 王玺; 曹玉琳; 陈宇晓; 聂玲; 张流强

    2011-01-01

    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 voltage 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× 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.%采用铑(Rh)靶45 kV X射线源进行了碲锌镉(CdZnTe)面元像素阵列探测器成像实验.实验结果表明:在探测距离1 mm,管电压45 kV条件下,管电流增大至20μA时,辐照中心区域像素单元信号丢失,出现围绕辐照中心区域的边缘高事件计数环形探测图像.随着管电流的增大,无响应像素区域扩大,探测器总体事件计数明显降低.进一步根据泊松方程建立了CdZnTe晶体内部电势分布模型,仿真结果表明:单位面积光子通量为5×105 mm-2·s-1时,由于CdZnTe晶体较低的空穴迁移率,晶体内部存在堆积空穴载流子形成的高空间电荷密度分布区域.晶体内部电场产生扭曲,电子载流子无法迁移至对应阳极位置,导致辐照中心区域产生信号屏蔽效应.

  6. Study and development of new CdTe and CdZnTe detection structures for X and {gamma} imagery; Etude et realisation de nouvelles structures de detection a base de CdTe et CdZnTe pour l`imagerie X et {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Rosaz, M

    1997-10-24

    The aim of this study is to show the interest of applying cadmium telluride (CdTe) for X- and {gamma}- ray imaging applications, with specific technological (via contact nature) and geometric (via Frisch grids) structures suited for each application. This work is divided into three different but complementary parts: the first part describes a simulation model which allows a better understanding of CdTe based {gamma}- ray detectors. The new feature of this model compared to previous ones, is that it is able to take into account the electric field`s non uniform spatial distribution inside the detector s. The results enable us to de-convolute the influence of material and contact parameters on the spectrometric performances (energy resolution and peak/valley ratio) of CdTe based detectors; the second part presents different technological structures deposited upon CdTe, (grown by two different methods, i.e Bridgman and High Pressure Bridgman). These structures were characterised in X- and {gamma}- ray detection; theoretical models are developed which allow a certain insight into the detection properties of each couple (material + contact); the third part deals with new contact geometries which allow a screening effect of the bulk (analogous to the Frisch grid effect in gaseous detectors) resulting in improved energy resolution and peak/valley ratios; encouraging first results on prototypes are presented and discussed. This work has allowed a better understanding of physical behaviour of CdTe based detectors, coupled with advances in technological issues to upgrade the overall performances of these detectors for application in X- and {gamma}- ray imaging. (author) 93 refs.

  7. Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    TROYER, G.L.

    2000-08-25

    High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% {at} 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse rise time versus photo peak position and resolution. These data were collected to investigate the effect of pulse rise time compensation on resolution and efficiency.

  8. CdZnTe room-temperature semiconductor operation in liquid scintillator

    CERN Document Server

    Stewart, D Y

    2008-01-01

    We demonstrate the first operation of CdZnTe room-temperature detectors in a liquid scintillator environment. This work follows conceptually the Heusser-type detector method of operating HPGe detectors in liquid nitrogen and liquid argon but instead for a far more practical room-temperature ensemble with the aim of achieving ultra-low background levels for radiation detection.

  9. Effect of chemical etching on the surface roughness of CdZnTe and CdMnTe gamma radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hossain,A.; Babalola, S.; Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Yang, G.; Guo, M.; Kochanowska, D.; Mycielski, A.; Burger, A.; James, R.B.

    2008-08-11

    Generally, mechanical polishing is performed to diminish the cutting damage followed by chemical etching to remove the remaining damage on crystal surfaces. In this paper, we detail the findings from our study of the effects of various chemical treatments on the roughness of crystal surfaces. We prepared several CdZnTe (CZT) and CdMnTe (CMT) crystals by mechanical polishing with 5 {micro}m and/or lower grits of Al{sub 2}O{sub 3} abrasive papers including final polishing with 0.05-{micro}m particle size alumina powder and then etched them for different periods with a 2%, 5% Bromine-Methanol (B-M) solution, and also with an E-solution (HNO{sub 3}:H{sub 2}O:Cr{sub 2}O{sub 7}). The material removal rate (etching rate) from the crystals was found to be 10 {micro}m, 30 {micro}m, and 15 {micro}m per minute, respectively. The roughness of the resulting surfaces was determined by the Atomic Force Microscopy (AFM) to identify the most efficient surface processing method by combining mechanical and chemical polishing.

  10. Point Defect Characterization in CdZnTe

    Energy Technology Data Exchange (ETDEWEB)

    Gul,R.; Li, Z.; Bolotnikov, A.; Keeter, K.; Rodriguez, R.; James, R.

    2009-03-24

    Measurements of the defect levels and performance testing of CdZnTe detectors were performed by means of Current Deep Level Transient Spectroscopy (I-DLTS), Transient Charge Technique (TCT), Current versus Voltage measurements (I-V), and gamma-ray spectroscopy. CdZnTe crystals were acquired from different commercial vendors and characterized for their point defects. I-DLTS studies included measurements of defect parameters such as energy levels in the band gap, carrier capture cross sections, and defect densities. The induced current due to laser-generated carriers was measured using TCT. The data were used to determine the transport properties of the detectors under study. A good correlation was found between the point defects in the detectors and their performance.

  11. Spectral response of THM grown CdZnTe crystals

    DEFF Research Database (Denmark)

    Chen, H.; Awadalla, S.A.; Harris, F.

    2008-01-01

    The spectral response of several crystals grown by the Traveling Heater Method (THM) were investigated. An energy resolution of 0.98% for a Pseudo Frisch-Grid of 4 × 4 × 9 mm3 and 2.1% FWHM for a coplanar-grid of size 11 × 11 × 5 mm3 were measured using 137Cs-662 keV. In addition a 4% FWHM at 122...

  12. CdZnTe Background Measurement at Balloon Altitudes

    CERN Document Server

    Bloser, P F; Narita, T; Harrison, F

    1998-01-01

    We report results of an experiment conducted in May 1997 to measure CdZnTe background and background reduction schemes in space flight conditions similar to those of proposed hard X-ray astrophysics missions. A 1 cm^2 CdZnTe detector was placed adjacent to a thick BGO anticoincidence shield and flown piggybacked onto the EXITE2 scientific balloon payload. The planar shield was designed to veto background countsproduced by local gamma-ray production in passive material and neutron interactions in the detector. The CdZnTe and BGO were partially surrounded by a Pb-Sn-Cu shield to approximate the grammage of an X-ray collimator, although the field of view was still ~2 pi sr. At an altitude of 127000 feet we find a reduction in background by a factor of 6 at 100 keV. The non-vetoed background is 9 X 10^{-4} cts /cm^2-sec-keV at 100 keV, about a factor of 2 higher than that of the collimated (4.5 deg FWHM) EXITE2 phoswich detector. We compare our recorded spectrum with that expected from simulations using GEANT and...

  13. Studies of crystalline CdZnTe radiation detectors and polycrystalline thin film CdTe for X-ray imaging applications

    CERN Document Server

    Ede, A

    2001-01-01

    The development of a replacement to the conventional film based X-ray imaging technique is required for many reasons. One possible route for this is the use of a large area film of a suitable semiconductor overlaid on an amorphous silicon readout array. A suitable semiconductor exists in cadmium telluride and its tertiary alloy cadmium zinc telluride. In this thesis the spectroscopic characteristics of commercially available CZT X- and gamma-radiation detectors are established. The electronic, optical, electro-optic, structural and compositional properties of these detectors are then investigated. The attained data is used to infer a greater understanding for the carrier transport in a CZT radiation detector following the interaction of a high energy photon. Following this a method used to fabricate large area films of CdTe on a commercial scale is described. This is cathodic electrodeposition from an aqueous electrolyte. The theory and experimental arrangement for this technique are described in detail with ...

  14. CdZnTe- and TlBr-detectors response simulation for registration of the mixed beta- and gamma-radiation

    Directory of Open Access Journals (Sweden)

    Skrypnyk A. I.

    2015-02-01

    Full Text Available One of the approaches for reconstructing the spectra of the mixed beta- and gamma-radiation, produced by wide band-gap semiconductor detectors, and the subsequent identification of radionuclides that are comprised in the mixture composition is a method based on various methods of spectral deconvolution. The presence of the detector response functions for each individual source of radiation is a key point in the studying such techniques. The response of TlBr- and CdZnTe-detectors to gamma-rays from 90Sr and 137Cs was simulated by Monte-Carlo method via Geant4 package. The computer experiments were conducted with using a β-filter and without it. It was shown that optimal thickness of the Al β-filter required for complete suppressing the conversion electrons in the 137Cs spectrum is 0.5 mm. The modification of 661.7 keV photopeaks with a using β-filter was investigated.

  15. 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.

  16. CdZnTe gamma ray spectrometer for orbital planetary missions

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, W. C. (William C.); Storms, S. A. (Steven A.); Fuller, K. R. (Kenneth R.); Moss, C. E. (Calvin E.); Browne, M. C. (Michael C.); Lawrence, David J. (David Jeffery),; Ianakiev, K. D.; Prettyman, T. H. (Thomas H.)

    2001-01-01

    Knowledge of surface elemental composition is needed to understand the formation and evolution of planetary bodies. Gamma rays and neutrons produced by the interaction of galactic cosmic rays with surface materials can be detected from orbit and analyzed to determine composition. Using gamma ray spectroscopy, major rock forming elements such as Fe, Ti, Al, Si, Mg, and Ca can be detected. The accuracy of elemental abundance is limited by the resolution of the spectrometer. For space missions, scintillators such as BGO and NaI(Tl) have been used for gamma ray spectroscopy. New planetary science missions are being planned to explore Mars, Mercury, the asteroid belt, and the outer planets. Significant improvements in the pulse height resolution relative to scintillation detectors can be made using CdZnTe, a new room temperature detector technology. For an orbiting instrument, a CdZnTe detector at least 16 cm{sup 3} in size is needed. A 4 x 4 array of 1-cm{sup 3} coplanar grid detectors can be manufactured that meets requirements for resolution and counting efficiency. The array will shielded from gamma rays produced in the spacecraft by a BGO detector. By improving pulse height resolution by a factor of three at low energy, the CdZnTe detector will be able to make accurate measurements of elements that are currently difficult to measure using scintillation technology. The BGO shield will provide adequate suppression of gamma rays originating in the spacecraft, enabling the gamma ray spectrometer to be mounted on the deck of a spacecraft. To test this concept, we are constructing a flight qualified, prototype CdZnTe detector array. The prototype consists of a 2 x 2 array of coplanar grid detectors. We will present the results of mechanical and electronic testing and radiation damage tests, and the performance of the array for gamma ray spectroscopy.

  17. Angular response of a W-collimated room-temperature-operated CdZnTe Frisch collar spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Kargar, Alireza [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Jones, Andrew M. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); McNeil, Walter J. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Harrison, Mark J. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)]. E-mail: mcgregor@ksu.edu

    2006-06-15

    The spatial resolution of a collimated CdZnTe Frisch collar detector was experimentally investigated for two different tungsten collimator designs using a {sup 198}Au gamma-ray source at 412 keV. A two-dimensional model for the detector-collimator-source geometry was developed and applied with some simplifying assumptions. The CdZnTe detector was fabricated from a single crystal using a copper shim as the Frisch collar. The detector fabrication process is briefly described. Pulse height spectra were collected from {sup 241}Am, {sup 198}Au and {sup 137}Cs using a 3.4x3.4x5.8 mm{sup 3} CdZnTe detector utilizing an insulated Frisch collar mounted inside a tungsten collimator. The resulting energy spectra are presented. Room-temperature energy resolution of 1.72% full-width at half-maximum (FWHM) was obtained for {sup 137}Cs at 662 keV without electronic correction. The two-dimensional model reasonably predicts the angular response of the CdZnTe detectors when inserted into two different collimators.

  18. ADVANCED READOUT ELECTRONICS FOR MULTIELEMENT CdZnTe SENSORS.

    Energy Technology Data Exchange (ETDEWEB)

    DE GERONIMO,G.; O CONNOR,P.; KANDASAMY,A.; GROSHOLZ,J.

    2002-07-08

    A generation of high performance front-end and read-out ASICs customized for highly segmented CdZnTe sensors is presented. The ASICs, developed in a multi-year effort at Brookhaven National Laboratory, are targeted to a wide range of applications including medical, safeguards/security, industrial, research, and spectroscopy. The front-end multichannel ASICs provide high accuracy low noise preamplification and filtering of signals, with versions for small and large area CdZnTe elements. They implement a high order unipolar or bipolar shaper, an innovative low noise continuous reset system with self-adapting capability to the wide range of detector leakage currents, a new system for stabilizing the output baseline and high output driving capability. The general-purpose versions include programmable gain and peaking time. The read-out multichannel ASICs provide fully data driven high accuracy amplitude and time measurements, multiplexing and time domain derandomization of the shaped pulses. They implement a fast arbitration scheme and an array of innovative two-phase offset-free rail-to-rail analog peak detectors for buffering and absorption of input rate fluctuations, thus greatly relaxing the rate requirement on the external ADC. Pulse amplitude, hit timing, pulse risetime, and channel address per processed pulse are available at the output in correspondence of an external readout request. Prototype chips have been fabricated in 0.5 and 0.35 {micro}m CMOS and tested. Design concepts and experimental results are discussed.

  19. Fast Neutron Detection Using Pixelated CdZnTe Spectrometers

    Science.gov (United States)

    Streicher, Michael; Goodman, David; Zhu, Yuefeng; Brown, Steven; Kiff, Scott; He, Zhong

    2017-07-01

    Fast neutrons are an important signature of special nuclear materials (SNMs). They have a low natural background rate and readily penetrate high atomic number materials that easily shield gamma-ray signatures. Therefore, they provide a complementary signal to gamma rays for detecting shielded SNM. Scattering kinematics dictate that a large nucleus (such as Cd or Te) will recoil with small kinetic energy after an elastic collision with a fast neutron. Charge carrier recombination and quenching further reduce the recorded energy deposited. Thus, the energy threshold of CdZnTe detectors must be very low in order to sense the small signals from these recoils. In this paper, the threshold was reduced to less than 5 keVee to demonstrate that the 5.9-keV X-ray line from 55Fe could be separated from electronic noise. Elastic scattering neutron interactions were observed as small energy depositions (less than 20 keVee) using digitally sampled pulse waveforms from pixelated CdZnTe detectors. Characteristic gamma-ray lines from inelastic neutron scattering were also observed.

  20. UF{sub 6} as a detector gas for fission studies

    Energy Technology Data Exchange (ETDEWEB)

    Eckardt, Christian; Enders, Joachim; Freudenberger, Martin; Neumann-Cosel, Peter von [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik; Goeoek, Alf; Oberstedt, Stephan [Commission of the European Communities, Geel (Belgium). Inst. for Reference Materials and Measurements (IRMM); Oberstedt, Andreas [Akademin foer Naturvetenskap och Teknik, Oerebro Univ. (Sweden); Chalmers Tekniska Hoegskola, Goeteborg (Sweden). Fundamental Fysik

    2013-07-01

    A Frisch-grid ionization chamber has been built to test a mixture of argon with gaseous UF{sub 6} and to study its properties as a counting gas. We present first results using increasing mass fractions of {sup 238}UF{sub 6} mixed into argon. The drift velocity of the electrons increases with the content of {sup 238}UF{sub 6}, while a good signal quality and energy resolution of the ionization chamber is preserved. Using uranium hexafluoride in the detector gas may give access to experiments where extremely high luminosity is required in combination with good angular and energy and/or mass resolution. Examples comprise the investigation of spontaneous fission of {sup 238}U, the study of parity non-conservation in the fission process, or precision measurements of fission fragments with good resolution using tagged photons in the entrance channel.

  1. IDeF-X ASIC for Cd(Zn)Te spectro-imaging systems

    OpenAIRE

    Limousin, O.; Gevin, O.; Lugiez, F.; Chipaux, R; Delagnes, E.; Dirks, B.; Horeau, B.

    2004-01-01

    Joint progresses in Cd(Zn)Te detectors, microelectronics and interconnection technologies open the way for a new generation of instruments for physics and astrophysics applications in the energy range from 1 to 1000 keV. Even working between -20 and 20 degrees Celsius, these instruments will offer high spatial resolution (pixel size ranging from 300 x 300 square micrometers to few square millimeters), high spectral response and high detection efficiency. To reach these goals, reliable, highly...

  2. The X-ray response of CdZnTe

    CERN Document Server

    Owens, A; Andersson, H; Gagliardi, T; Krumrey, M; Nenonen, S; Peacock, A; Taylor, I; Troeger, L

    2002-01-01

    We report the results of a series of X-ray measurements on a 3.1 mm sup 2 , 2.5 mm thick CdZnTe detector carried out at the BESSY II and HASYLAB synchrotron radiation facilities. The detector energy response function was found to be linear over the energy range 2.3-100 keV with an average rms non-linearity of 0.6%, consistent with statistics. At room temperature, under full-area illumination, the FWHM energy resolution was 1.6 keV at 5.9 keV rising to 2.9 keV at 59.54 keV. At a reduced detector temperature of -20 deg. C, these fall to 380 and 818 eV FWHM, respectively. Under pencil beam illumination, the measured energy resolution at 2.5 keV was 360 eV FWHM rising to 1558 eV at 100 keV. By best fitting the expected resolution function to the experimental data, we derive a value for the Fano factor of (0.099+-0.02). Cooling the detector to -50 deg. C, resulted in no noticeable difference in DELTA E above 60 keV, but a 40% reduction at energies <10 keV. At 5.9 keV, the measured resolution under full-area ill...

  3. A double-Bragg detector with digital signal processing for the event-by-event study of fission in actinide nuclei

    Science.gov (United States)

    Frost, R. J. W.; Smith, A. G.

    2016-09-01

    In the current paper, a windowless double-Bragg chamber incorporating full signal digitisation has been developed for the purpose of studying the energy (E), mass (A), charge (Z) and angular distributions (θ, Φ) of nuclei generated by fission. This device measures E for each fission fragment by collection of the charge produced during ionisation of the fill gas. Subsequent digitisation of the signals from each of two anodes yields information on dE/dx, as well as electron collection time, which can be further used for polar angle (θ) determination. Frisch-grid and cathode signals are also digitised and are used both for anode signal correction and to produce further information on θ. To verify the operation of this detector, three angular determination techniques from the literature were implemented, and the results were found to be consistent with the referenced paper. Current results from the spontaneous fission of 252Cf are presented.

  4. Study and optimisation of the high energy detector in Cd(Zn)Te of the Simbol-X space mission for X and gamma astronomy; Etude et optimisation du plan de detection de haute energie en Cd(Zn)Te pour la mission spatiale d'observation astronomie X et gamma SIMBOL-X

    Energy Technology Data Exchange (ETDEWEB)

    Meuris, A.

    2009-09-15

    Stars in final phases of evolution are sites of highest energetic phenomena of the Universe. The understanding of their mechanisms is based on the observation of the X and gamma rays from the sources. The Simbol-X French-Italian project is a novel concept of telescope with two satellites flying in formation. This space mission combines upgraded optics from X-ray telescopes with detection Systems from gamma-ray telescopes. CEA Saclay involved in major space missions for gamma astronomy is in charge of the definition and the design of the High Energy Detector (HED) of Simbol-X to cover the spectral range from 8 to 80 keV. Two generations of micro-cameras called Caliste have been designed, fabricated and tested. They integrate cadmium telluride (CdTe) crystals and optimised front-end electronics named Idef-X. The hybridization technique enables to put them side by side as a mosaic to achieve for the first time a CdTe detection plane with fine spatial resolution (600 {mu}m) and arbitrarily large surface. By setting up test benches and leading test campaigns, I was involved in the fabrication of Caliste prototypes and I assessed temporal, spatial and spectral resolutions. At the conclusion of experiments and simulations, I propose a detector type, operating conditions and digital processing on board the spacecraft to optimise HED performance. The best detector candidate is CdTe Schottky, well suited to high resolution spectroscopy; however, it suffers from lost in stability during biasing. Beyond Simbol-X mission, I studied theoretically and experimentally this kind of detector to build an updated model that can apply to other projects of gamma spectroscopy and imaging. (author)

  5. CHARACTERIZATION OF SECONDARY PHASES AND OTHER DEFECTS IN CDZNTE

    Energy Technology Data Exchange (ETDEWEB)

    Duff, M.

    2010-06-30

    Semiconducting CdZnTe or 'CZT' crystals are very suitable for use as a room temperature-based gamma radiation spectrometer. During the last decade, modifications in growth methods for CZT have significantly improved the quality of the produced crystals however there are material features that can influence the performance of these materials as radiation detectors. For example, various structural heterogeneities within the CZT crystals, such as, pipes, voids, polycrystallinity, and secondary phases (SP) can have a negative impact on the detector performance. In this study, a CZT material was grown by the modified vertical Bridgman growth (MVB) method with zone leveled growth in the absence of excess Te in the melt. Numerous SP were imaged using transmission IR at a volume % of 0.002. Samples from this material were analyzed using various analytical techniques to evaluate its electrical properties, purity and detector performance as radiation spectrometers and to determine the morphology, dimension and elemental /structural composition of one of the SP in this material. This material was found to have a high resistivity and good radiation spectrometer performance. It had SPs that were rich in calcium (Ca), carbon (C) and oxygen (O) (possibly CaCO{sub 3}) or only C and O that were 5 {micro}m or less in diameter.

  6. Live-monitoring of Te inclusions laser-induced thermo-diffusion and annealing in CdZnTe crystals

    Energy Technology Data Exchange (ETDEWEB)

    Zappettini, A.; Zambelli, N.; Benassi, G.; Calestani, D. [Istituto Materiali Elettronica e Magnetismo – Consiglio Nazionale delle Ricerche, Parma (Italy); Pavesi, M. [Istituto Materiali Elettronica e Magnetismo – Consiglio Nazionale delle Ricerche, Parma (Italy); Istituto di Fisica e Scienze della Terra, Università degli Studi di Parma, Parma (Italy)

    2014-06-23

    The presence of Te inclusions is one of the main factors limiting performances of CdZnTe crystals as X-ray detectors. We show that by means of infrared laser radiation it is possible to move and anneal tellurium inclusions exploiting a thermo-diffusion mechanism. The process is studied live during irradiation by means of an optical microscope equipment. Experimental conditions, and, in particular, energy laser fluence, for annealing inclusions of different dimensions are determined.

  7. Using a pulsed laser beam to investigate the feasibility of sub-pixel position resolution with time-correlated transient signals in 3D pixelated CdZnTe detectors

    Science.gov (United States)

    Giraldo, L. Ocampo; Bolotnikov, A. E.; Camarda, G. S.; Cheng, S.; De Geronimo, G.; McGilloway, A.; Fried, J.; Hodges, D.; Hossain, A.; Ünlü, K.; Petryk, M.; Vidal, V.; Vernon, E.; Yang, G.; James, R. B.

    2017-09-01

    We evaluated the X-Y position resolution achievable in 3D pixelated detectors by processing the signal waveforms readout from neighboring pixels. In these measurements we used a focused light beam, down to 10 μm, generated by a 1 mW pulsed laser (650 nm) to carry out raster scans over selected 3×3 pixel areas, while recording the charge signals from the 9 pixels and the cathode using two synchronized digital oscilloscopes.

  8. Low-energy CZT detector array for the ASIM mission

    DEFF Research Database (Denmark)

    Cenkeramaddi, Linga Reddy; Genov, Georgi; Kohfeldt, Anja

    2012-01-01

    In this article we introduce the low-energy CZT (CdZnTe) 16 384-pixel detector array on-board the Atmosphere Space Interaction Monitor (ASIM), funded by the European Space Agency. This detector is a part of the larger Modular X-and Gamma-ray sensor (MXGS). The CZT detector array is sensitive...

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

    Energy Technology Data Exchange (ETDEWEB)

    Norarat, Rattanaporn, E-mail: rattanaporn@rmutl.ac.th [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Faculty of Science and Agriculture, Rajamangala University of Technology Lanna, Chiang Rai, 57120 Chiang Rai (Thailand); Department of Physics, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014 (Finland); Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Roux, Adrien; Stoppini, Luc [Tissue Engineering Laboratory, Campus Biotech, Chemin des Mines 9, Geneva (Switzerland); Whitlow, Harry J. [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland)

    2015-04-01

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

  10. Analysis of Etched CdZnTe Substrates

    Science.gov (United States)

    Benson, J. D.; Bubulac, L. O.; Jaime-Vasquez, M.; Lennon, C. M.; Arias, J. M.; Smith, P. J.; Jacobs, R. N.; Markunas, J. K.; Almeida, L. A.; Stoltz, A.; Wijewarnasuriya, P. S.; Peterson, J.; Reddy, M.; Jones, K.; Johnson, S. M.; Lofgreen, D. D.

    2016-09-01

    State-of-the-art as-received (112)B CdZnTe substrates have been examined for surface impurity contamination and polishing residue. Two 4 cm × 4 cm and one 6 cm × 6 cm (112)B state-of-the-art as-received CdZnTe wafers were analyzed. A maximum surface impurity concentration of Al = 1.7 × 1015 atoms cm-2, Si = 3.7 × 1013 atoms cm-2, Cl = 3.12 × 1015 atoms cm-2, S = 1.7 × 1014 atoms cm-2, P = 1.1 × 1014 atoms cm-2, Fe = 1.0 × 1013 atoms cm-2, Br = 1.2 × 1014 atoms cm-2, and Cu = 4 × 1012 atoms cm-2 was observed on the as-received CdZnTe wafers. CdZnTe particulates and residual SiO2 polishing grit were observed on the surface of the as-received (112)B CdZnTe substrates. The polishing grit/CdZnTe particulate density on CdZnTe wafers was observed to vary across a 6 cm × 6 cm wafer from ˜4 × 107 cm-2 to 2.5 × 108 cm-2. The surface impurity and damage layer of the (112)B CdZnTe wafers dictate that a molecular beam epitaxy (MBE) preparation etch is required. The contamination for one 4 cm × 4 cm and one 6 cm × 6 cm CdZnTe wafer after a standard MBE Br:methanol preparation etch procedure was also analyzed. A maximum surface impurity concentration of Al = 2.4 × 1015 atoms cm-2, Si = 4.0 × 1013 atoms cm-2, Cl = 7.5 × 1013 atoms cm-2, S = 4.4 × 1013 atoms cm-2, P = 9.8 × 1013 atoms cm-2, Fe = 1.0 × 1013 atoms cm-2, Br = 2.9 × 1014 atoms cm-2, and Cu = 5.2 × 1012 atoms cm-2 was observed on the MBE preparation-etched CdZnTe wafers. The MBE preparation-etched surface contamination consists of Cd(Zn)Te particles/flakes. No residual SiO2 polishing grit was observed on the (112)B surface.

  11. Development of a simplified simulation model for performance characterization of a pixellated CdZnTe multimodality imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, P; Santos, A [Departamento de IngenierIa Electronica, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Darambara, D G [Joint Department of Physics, Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Fulham Road, London SW3 6JJ (United Kingdom)], E-mail: pguerra@die.um.es

    2008-02-21

    Current requirements of molecular imaging lead to the complete integration of complementary modalities in a single hybrid imaging system to correlate function and structure. Among the various existing detector technologies, which can be implemented to integrate nuclear modalities (PET and/or single-photon emission computed tomography with x-rays (CT) and most probably with MR, pixellated wide bandgap room temperature semiconductor detectors, such as CdZnTe and/or CdTe, are promising candidates. This paper deals with the development of a simplified simulation model for pixellated semiconductor radiation detectors, as a first step towards the performance characterization of a multimodality imaging system based on CdZnTe. In particular, this work presents a simple computational model, based on a 1D approximate solution of the Schockley-Ramo theorem, and its integration into the Geant4 application for tomographic emission (GATE) platform in order to perform accurately and, therefore, improve the simulations of pixellated detectors in different configurations with a simultaneous cathode and anode pixel readout. The model presented here is successfully validated against an existing detailed finite element simulator, the multi-geometry simulation code, with respect to the charge induced at the anode, taking into consideration interpixel charge sharing and crosstalk, and to the detector charge induction efficiency. As a final point, the model provides estimated energy spectra and time resolution for {sup 57}Co and {sup 18}F sources obtained with the GATE code after the incorporation of the proposed model.

  12. XA readout chip characteristics and CdZnTe spectral measurements

    Energy Technology Data Exchange (ETDEWEB)

    Barbier, L.M.; Birsa, F.; Odom, J. [NASA/Goddard Space Flight Center, Greenbelt, MD (United States)] [and others

    1999-02-01

    The authors report on the performance of a CdZnTe (CZT) array readout by an XA (X-ray imaging chip produced at the AMS foundry) application specific readout chip (ASIC). The array was designed and fabricated at NASA/Goddard Space Flight Center (GSFC) as a prototype for the Burst Arc-Second Imaging and Spectroscopy gamma-ray instrument. The XA ASIC was obtained from Integrated Detector and Electronics (IDE), in Norway. Performance characteristics and spectral data for {sup 241}Am are presented both at room temperature and at {minus}20 C. The measured noise ({sigma}) was 2.5 keV at 60 keV at room temperature. This paper represents a progress report on work with the XA ASIC and CZT detectors. Work is continuing and in particular, larger arrays are planned for future NASA missions.

  13. Characterisation of vapour grown CdZnTe crystals using synchrotron X-ray topography

    Science.gov (United States)

    Egan, Christopher K.; Choubey, Ashutosh; Moore, Moreton; Cernik, Robert J.

    2012-03-01

    Synchrotron white beam X-ray topography has been used to characterise bulk crystal defects of thick vapour grown CdZnTe crystals. Whole 50 mm diameter wafers with thicknesses in the range of 2-3 mm were sliced from boules grown by the multi-tube physical vapour transport method and analysed by diffraction topography in a transmission geometry. A variety of defects were observed including cracks, voids and grain boundaries. The largest quantity of defects observed were sub-grains appearing as localised increased intensity in the topographs. The periphery of the wafers showed the highest number of defects, whereas central regions where largely defect-free. We failed to observe any inclusions or precipitates within these crystals. Surface damage from wire-saw cutting was also observed on poorly processed wafers; these defects were otherwise invisible to standard characterisation methods. X-ray topography has proven to be a useful tool for non-destructively investigating bulk extended defects in CdZnTe crystals for radiation detector applications.

  14. Response of CZT drift-strip detector to X- and gamma rays

    DEFF Research Database (Denmark)

    Kuvvetli, Irfan; Budtz-Jørgensen, Carl; Gerward, Leif

    2001-01-01

    The drift-strip method for improving the energy response of a CdZnTe (CZT) detector to hard X- and gamma rays is discussed. Results for a 10 x 10 x 3 mm(3) detector crystal demonstrate a remarkable improvement of the energy resolution. The full width at half maximum (FWHM) is 2.18 keV (3.6%), 2...

  15. SWAD: inherent photon counting performance of amorphous selenium multi-well avalanche detector

    Science.gov (United States)

    Stavro, Jann; Goldan, Amir H.; Zhao, Wei

    2016-03-01

    Photon counting detectors (PCDs) have the potential to improve x-ray imaging, however they are still hindered by several performance limitations and high production cost. By using amorphous Selenium (a-Se) the cost of PCDs can be significantly reduced compared to crystalline materials and enable large area detector fabrication. To overcome the problem of low carrier mobility and low charge conversion gain in a-Se, we are developing a novel direct conversion a- Se field-Shaping multi-Well Avalanche Detector (SWAD). SWAD circumvents the charge transport limitation by using a Frisch grid built within the readout circuit, reducing charge collection time to ~200 ns. Field shaping permits depth independent avalanche gain in wells, resulting in total conversion gain that is comparable to Si and CdTe. In the present work we investigate the effects of charge sharing and energy loss to understand the inherent photon counting performance for SWAD at x-ray energies used in breast imaging applications (20-50keV). The energy deposition profile for each interacting x-ray was determined with Monte Carlo simulation. For the energy ranges we are interested in, photoelectric interaction dominates, with a k-fluorescence yield of approximately 60%. Using a monoenergetic 45 keV beam incident on a target pixel in 400um of a-Se, our results show that only 20.42 % and 22.4 % of primary interacting photons have kfluorescence emissions which escape the target pixel for 100um and 85um pixel sizes respectively, demonstrating SWAD's potential for high spatial resolution applications.

  16. PHOTOINDUCED CURRENTS IN CDZNTE CRYSTALS AS A FUNCTION OF ILLUMINATION WAVELENGTH

    Energy Technology Data Exchange (ETDEWEB)

    Teague, L.; Washington, A.; Duff, M.

    2012-04-23

    We report variations in the currents of CdZnTe semiconductor crystals during exposure to a series of light emitting diodes of various wavelengths ranging from 470 to 950 nm. The changes in the steady-state current of one CdZnTe crystal with and without illumination along with the time dependence of the illumination effects are discussed. Analysis of the de-trapping and transient bulk currents during and after optical excitation yield insight into the behaviour of charge traps within the crystal. Similar behaviour is observed for illumination of a second CdZnTe crystal suggesting that the overall illumination effects are not crystal dependent.

  17. Charge collection characteristics of Frisch collar CdZnTe gamma-ray spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Mark J. [Kansas State University, Manhattan, KS 66506 (United States)], E-mail: harrison@ksu.edu; Kargar, Alireza; McGregor, Douglas S. [Kansas State University, Manhattan, KS 66506 (United States)

    2007-08-21

    A collimated {sup 198}Au source was used to determine the charge collection efficiency (CCE) at several locations along the length of a 3.4x3.4x5.5 mm{sup 3} CdZnTe bar detector, both in planar configuration and with Frisch collars of varying length. For each configuration, a 0.50-mm-long region spanning the width of the device was irradiated with 411-keV gamma rays produced by a neutron-activated gold foil. Irradiation began at the cathode and stepped in 0.50-mm steps toward the anode, with a spectrum being collected at each location. By observing the channel location of the full-energy peak in each collected spectrum, an average CCE was determined for each irradiated region. The CCE was found to vary nearly linearly along the length of the device in the planar configuration, starting at a peak value of 89% and dropping to a minimum measured value of 26% near the anode. The addition of a Frisch collar covering the entire length of the crystal greatly altered the CCE profile, which remained near 87% for approximately two-thirds of the length, then sharply dropped near the anode. Results were confirmed by theoretical models. Further CCE mapping was also completed for devices with Frisch collars of various lengths. Those results are reported as well.

  18. Evaluation of a multistage CdZnTe Compton camera for prompt γ imaging for proton therapy

    Science.gov (United States)

    McCleskey, M.; Kaye, W.; Mackin, D. S.; Beddar, S.; He, Z.; Polf, J. C.

    2015-06-01

    A new detector system, Polaris J from H3D, has been evaluated for its potential application as a Compton camera (CC) imaging device for prompt γ rays (PGs) emitted during proton radiation therapy (RT) for the purpose of dose range verification. This detector system consists of four independent CdZnTe detector stages and a coincidence module, allowing the user to construct a Compton camera in different geometrical configurations and to accept both double and triple scatter events. Energy resolution for the 662 keV line from 137Cs was found to be 9.7 keV FWHM. The raw absolute efficiencies for double and triple scatter events were 2.2 ×10-5 and 5.8 ×10-7, respectively, for γs from a 60Co source. The position resolution for the reconstruction of a point source from the measured CC data was about 2 mm. Overall, due to the low efficiency of the Polaris J CC, the current system was deemed not viable for imaging PGs emitted during proton RT treatment delivery. However, using a validated Monte Carlo model of the CC, we found that by increasing the size of the detectors and placing them in a two stage configuration, the efficiency could be increased to a level to make PG imaging possible during proton RT.

  19. Recent developments in semiconductor gamma-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Luke, Paul N.; Amman, Mark; Tindall, Craig; Lee, Julie S.

    2003-10-28

    The successful development of lithium-drifted Ge detectors in the 1960's marked the beginning of the significant use of semiconductor crystals for direct detection and spectroscopy of gamma rays. In the 1970's, high-purity Ge became available, which enabled the production of complex detectors and multi-detector systems. In the following decades, the technology of semiconductor gamma-ray detectors continued to advance, with significant developments not only in Ge detectors but also in Si detectors and room-temperature compound-semiconductor detectors. In recent years, our group at Lawrence Berkeley National Laboratory has developed a variety of gamma ray detectors based on these semiconductor materials. Examples include Ge strip detectors, lithium-drifted Si strip detectors, and coplanar-grid CdZnTe detectors. These advances provide new capabilities in the measurement of gamma rays, such as the ability to perform imaging and the realization of highly compact spectroscopy systems.

  20. Characterization of semi-insulating materials by photoinduced current transient spectroscopy: Fe doped INP for micro-optoelectronics and CdZnTe for nuclear detection; Caracterisation de materiaux semi-isolants par spectroscopie de transitoirede courant photoinduit: materiaux INP dopes Fe pour la micro-optoelectronique et CDZNTE pour la detection nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Cherkaoui, K

    1998-07-01

    The need of semi-insulating materials, of great quality, concerns various application domains. For instance, the very resistive substrates InP and CdZnTe are respectively adapted to the micro-optoelectronic circuits and to nuclear detectors. These two materials have been characterized by the thermal photoinduced current transient spectroscopy. The first part of this thesis is the defects analysis of annealing InP substrates, to understand the compensation process of this material. Two activation energy levels around 0,2 to 0,4 eV resulting from the thermal treatment have been detected. The iron omnipresence in the substrates, even undoped, has been noticed. It is then necessary to take into account the iron presence to understand the compensation process in these InP annealing substrates. the second part presents the study of the CdZnTe material, elaborated by the Bridgman method, to emphasize the defects leading to the decrease of the detector performances. The presence of three deep levels, near the forbidden band middle, is in relation with the detectors performances. (A.L.B.)

  1. Interface chemistry of CdZnTe films studied by a peel-off approach

    Science.gov (United States)

    Tao, Jun; Xu, Haitao; Zhang, Yuelu; Ji, Huanhuan; Xu, Run; Huang, Jian; Zhang, Jijun; Liang, Xiaoyan; Tang, Ke; Wang, Linjun

    2016-12-01

    CdZnTe films with thickness above 50 μm were deposited at temperatures of 200-500 °C by Close Space Sublimation method. A peel-off approach has been adopted to study the interface chemistry of CdZnTe thick films. For all the CdZnTe films, the scanning electron microscopy images show the small and round-like grains formed at interface in contrast to the large ordered grains at surface. For CdZnTe films grown at a low substrate temperature of 200 °C, the interface layer between CdZnTe and substrate is mixed with Te and CdTe, as evidenced by X-ray diffraction, Raman and X-ray photoelectron spectroscopy results. The thickness of the interface layer can be estimated to be 84 nm by depth profile using X-ray photoelectron spectroscopy. In contrast, a thin interface layer less than 14 nm is found at a high substrate temperature of 500 °C. The limited reaction of Te2 and Cd (Zn) to CdZnTe at a low growth temperature is responsible for the formation of the thick interface layer and a slow deposition rate at the nucleation stage.

  2. Optimization of control parameters of CdZnTe ACRT-Bridgman single crystal growth

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    [1]Kennedey, J. J., Amirtharaj, P. M., Boyd, P. R. Et al., Growth and characterization of Cd1-xZnxTe and Hg1-yZnyTe, J. Cryst. Growth, 1988, 86: 93-99.[2]Tanaka, A., Masa, Y., Seto, S. et al., Zinc and selenium co-doped CdTe substrates lattice matched to HgCdTe, J. Cryst. Growth, 1989, 94: 166-170.[3]Sen, S., Stanard, J. E., Developments in the bulk growth of Cd1-xZnxTe for substrates, Prog. Crystal Growth and Charact., 1994, 29: 253-273.[4]Azoulay, M., Rotter, S., Gafni, G. et al., Zinc segregation in CdZnTe grown under Cd/Zn partial pressure control, J. Cryst. Growth, 1992, 117: 276-280.[5]Lee, T. S., Lee, S. B., Kim, J. M. et al., Vertical Bridgman techniques to homogenize zinc composition of CdZnTe substrates, J. Electronic Materials, 1995, 24: 1057-1059.[6]Mühlberg, M., Rudolph, P., Genzel, C. Et al., Crystalline and chemical quality of CdTe and Cd1-xZnxTe grown by the Bridgman method in low temperature gradients, J. Cryst. Growth, 1990, 101: 275-280.[7]Cheuvart, P., El-Hanani, U., Schneider, D. et al., CdTe and CdZnTe crystal growth by horizontal Bridgman technique, J. Cryst. Growth, 1990, 101: 270-274.[8]Lu, Y. C., Shiau, J. J., Fiegelson, R. S. et al., Effect of vibrational stirring on the quality of Bridgman-grown CdTe, J. Cryst. Growth, 1990, 102: 807-813.[9]Butler, J. F., Doty, F. P., Apotovsky, B. Et al., γ-ray and X-ray detectors manufactured from Cd1-xZnxTe grown by a high-pressure Bridgman method, Mater. Sci. & Eng. B, 1993, 16: 291-295.[10]Capper, P., The role of accelerated crucible rotation in the growth of Hg1-xCdxTe and CdTe/CdZnTe, Prog. Crystal Growth and Charact., 1994, 28: 1-55.[11]Schulz-Dubois, E. O., Accelerated crucible rotation: hydrodynamics and stirring effect, J. Cryst. Growth, 1971, 12: 81-87.[12]Capper, P., Gosney, J. J. G., Jones, C. L. et al., Fluid flows in tall narrow containers by ACRT, Journal of Electronic Materials, 1986 15(6): 361-370.[13]Distanov, V. E., Kirdyashkin, A

  3. A fission fragment detector for correlated fission output studies

    Energy Technology Data Exchange (ETDEWEB)

    Mosby, S., E-mail: smosby@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tovesson, F.; Couture, A. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Duke, D.L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Colorado School of Mines, Golden, CO 80401 (United States); Kleinrath, V. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Idaho State University, Pocatello, ID 83201 (United States); Meharchand, R.; Meierbachtol, K.; O' Donnell, J.M.; Perdue, B.; Richman, D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Shields, D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Colorado School of Mines, Golden, CO 80401 (United States)

    2014-09-01

    A digital data acquisition system has been combined with a double Frisch gridded ionization chamber for use at both moderated and unmoderated neutron sources at the Los Alamos Neutron Science (LANSCE) facility. The high efficiency of the instrument combined with intense LANSCE beams and new acquisition system permits fission output measurements across 11 orders of magnitude incident neutron energy. The acquisition and analysis system is presented along with the first in-beam performance tests of the setup.

  4. Modelling semiconductor pixel detectors

    CERN Document Server

    Mathieson, K

    2001-01-01

    expected after 200 ps in most cases. The effect of reducing the charge carrier lifetime and examining the charge collection efficiency has been utilised to explore how these detectors would respond in a harsh radiation environment. It is predicted that over critical carrier lifetimes (10 ps to 0.1 ns) an improvement of 40 % over conventional detectors can be expected. This also has positive implications for fabricating detectors, in this geometry, from materials which might otherwise be considered substandard. An analysis of charge transport in CdZnTe pixel detectors has been performed. The analysis starts with simulation studies into the formation of contacts and their influence on the internal electric field of planar detectors. The models include a number of well known defect states and these are balanced to give an agreement with a typical experimental I-V curve. The charge transport study extends to the development of a method for studying the effect of charge sharing in highly pixellated detectors. The ...

  5. Gamma ray detector modules

    Science.gov (United States)

    Capote, M. Albert (Inventor); Lenos, Howard A. (Inventor)

    2009-01-01

    A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C. An encapsulant is disposed between the interposer circuit card first surface and the semiconductor detector array substrate first surface, encapsulating the solder columns, the encapsulant curing at a temperature no greater than 120 degrees C.

  6. Study of a new architecture of gamma cameras with Cd/ZnTe/CdTe semiconductors; Etude d'une nouvelle architecture de gamma camera a base de semi-conducteurs CdZnTe /CdTe

    Energy Technology Data Exchange (ETDEWEB)

    Guerin, L

    2007-11-15

    This thesis studies new semi conductors for gammas cameras in order to improve the quality of image in nuclear medicine. The chapter 1 reminds the general principle of the imaging gamma, by describing the radiotracers, the channel of detection and the types of Anger gamma cameras acquisition. The physiological, physical and technological limits of the camera are then highlighted, to better identify the needs of future gamma cameras. The chapter 2 is dedicated to a bibliographical study. At first, semi-conductors used in imaging gamma are presented, and more particularly semi-conductors CDTE and CdZnTe, by distinguishing planar detectors and monolithic pixelated detectors. Secondly, the classic collimators of the gamma cameras, used in clinical routine for the most part of between them, are described. Their geometry is presented, as well as their characteristics, their advantages and their inconveniences. The chapter 3 is dedicated to a state of art of the simulation codes dedicated to the medical imaging and the methods of reconstruction in imaging gamma. These states of art allow to introduce the software of simulation and the methods of reconstruction used within the framework of this thesis. The chapter 4 presents the new architecture of gamma camera proposed during this work of thesis. It is structured in three parts. The first part justifies the use of semiconducting detectors CdZnTe, in particular the monolithic pixelated detectors, by bringing to light their advantages with regard to the detection modules based on scintillator. The second part presents gamma cameras to base of detectors CdZnTe (prototypes or commercial products) and their associated collimators, as well as the interest of an association of detectors CdZnTe in the classic collimators. Finally, the third part presents in detail the HiSens architecture. The chapter 5 describes both software of simulation used within the framework of this thesis to estimate the performances of the Hi

  7. Extended defects in as-grown CdZnTe

    Energy Technology Data Exchange (ETDEWEB)

    Xu, L.; Bolotnikov, A.E.; Hossain, A.; Kim, K-H.; Gul, R.; Yang, G.; Camarda, G.S.; Marchini, L.; Cui, Y.; James, R.B.; Xu, Y.; Wang, T.; Jie, W.

    2010-08-01

    We characterized samples cut from different locations in as-grown CdZnTe (CZT) ingots, using Automated Infrared (IR) Transmission Microscopy and White Beam X-ray Diffraction Topography (WBXDT), to locate and identify the extended defects in them. Our goal was to define the distribution of these defects throughout the entire ingot and their effects on detectors’ performance as revealed by the pulse-height spectrum. We found the highest- and the lowest- concentration of Te inclusions, respectively, in the head and middle part of the ingot, which could serve as guidance in selecting samples. Crystals with high concentration of Te inclusions showed high leakage current and poor performance, because the accumulated charge loss around trapping centers associated with Te inclusions distorts the internal electric field, affects the carrier transport properties inside the crystal, and finally degrades the detector’s performance. In addition, other extended defects revealed by the WBXDT measurements severely reduced the detector’s performance, since they trap large numbers of electrons, leading to a low signal for the pulse-height spectrum, or none whatsoever. Finally, we fully correlated the detector’s performance with our information on the extended defects gained from both the IR- and the WBXDT-measurements.

  8. Developments in semiconductor detector technology and new applications -- symposium summary

    CERN Document Server

    Kamae, T

    1999-01-01

    Most traditional silicon-based detectors have advanced close to their intrinsic limits and optimization of the front-end electronics has become most crucial in improving performance for specific applications. CdZnTe and CdTe, the most promising in the hard X-ray band, are now finding real commercial applications. Si drift-type detectors are among the few silicon-based detectors whose merits have not been fully exploited. When they are used as photodiodes and combined with new high-Z, high light-yield scintillators (eg. GSO), we can expect a break-through in MeV gamma-ray detection.

  9. Study of ammonium fluoride passivation time on CdZnTe bulk crystal wafers

    Energy Technology Data Exchange (ETDEWEB)

    Bensalah, H.; Crocco, J.; Carcelen, V.; Plaza, J.L.; Zheng, Q.; Dieguez, E. [Crystal Growth Laboratory, Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Marchini, L. [IMEM-CNR, Parma (Italy); Zanichelli, M. [Department of Physics, University of Parma (Italy); Dominguez, G.; Soriano, L. [Departamento de Fisica Aplicada and Instituto de Ciencias de Materiales Nicolas Cabrera, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2011-07-15

    The chemical etching and the passivation processes of CdZnTe wafers were studied. The treatment effects were tested through an X-Ray Photoelectron Spectroscopy (XPS) analysis and I-V measurement. The chemical etching in 2%Br-MeOH solution may effectively remove the damaged layer and improve the ohmic contact between CdZnTe wafer and Au electrodes making rich the surface with Te. After different etching times, the CdZnTe wafers were passivated with NH{sub 4}F/H{sub 2}O{sub 2}.CdZnTe wafer passivated immediately after etching showed the best passivation efficiency because the enriched Te on the surface was fully oxidized to TeO{sub 2}, which results in the thickest oxide layer, and the most stoichiometric surface. Also the surface leakage current was reduced in comparison with the sample passivated 24 h after etching. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Effect of de-trapping on carrier transport process in semi-insulating CdZnTe

    Science.gov (United States)

    Guo, Rong-Rong; Jie, Wan-Qi; Zha, Gang-Qiang; Xu, Ya-Dong; Feng, Tao; Wang, Tao; Du, Zhuo-Tong

    2015-06-01

    The effect of de-trapping on the carrier transport process in the CdZnTe detector is studied by laser beam-induced transient current (LBIC) measurement. Trapping time, de-trapping time, and mobility for electrons are determined directly from transient waveforms under various bias voltages. The results suggest that an electric field strengthens the capture and emission effects in trap center, which is associated with field-assisted capture and the Poole-Frenkel effect, respectively. The electron mobility is calculated to be 950 cm2/V·s and the corresponding electron mobility-lifetime product is found to be 1.32×10-3 cm2/V by a modified Hecht equation with considering the surface recombination effect. It is concluded that the trapping time and de-trapping time obtained from LBIC measurement provide direct information concerning the transport process. Project supported by the National Instrumentation Program, China (Grant No. 2011YQ040082), the National Natural Science Foundation of China (Grant Nos. 61274081, 51372205, and 51202197), the National 973 Project of China (Grant No. 2011CB610400), the China Postdoctoral Science Foundation (Grant No. 2014M550509), and the 111 Project of China (Grant No. B08040).

  11. Synthesis and fluorescence properties of water-soluble CdZnTe quantum dots%水溶性 CdZnTe 量子点制备及光谱性能

    Institute of Scientific and Technical Information of China (English)

    陈燕清; 龙冠虹

    2014-01-01

    以巯基丙酸(MPA)为修饰剂,在水溶液中制备出 CdZnTe 量子点(QDs)。研究了 ZnCd 摩尔比,pH,反应时间等因素对 CdZnTe 量子点荧光性能的影响。为了进一步改善 CdZnTe 量子点的水溶性,采用聚乙烯亚胺(PEI)对 CdZnTe 量子点进一步进行包裹,探讨了前驱体溶液 pH 对 PEI 包裹 CdZnTe 量子点荧光性能的影响。相比于 CdTe 量子点,CdZnTe 量子点具有更强的荧光性能,PEI 修饰的 CdZnTe 量子点的稳定性更好。通过荧光光谱仪,红外光谱仪,X-射线粉末衍射仪,透射电镜对所制得量子点进行了表征。%Water-soluble CdZnTe quantum dots (QDs)were synthesized in aqueous solution by using mer-captopropionic acid (MPA)as stabilizer.The influence of the molar ratio of CdZn,pHand aging time on photoluminescence of obtained QDs had been studied.To further improve the solubility of CdZnTe QDs, surfaces of water-soluble quantum dots were modified by polyethyleneimine (PEI),and the effect of pH on CdZnTe QDs coated with PEI was discussed as well.CdZnTe QDs acquired better photoluminescence and decreased biological toxicity compared with CdTe QDs.The modification using PEI highly enhanced the lu-minescent property of CdZnTe QDs.The water-soluble CdZnTe QDs were characterized by fluorescence e-mission spectra,infrared spectra (IR),transmission electron microscopy (TEM),and X-ray powder diffrac-tion (XRD).

  12. 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.

  13. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  14. Surface morphology study on CdZnTe crystals by atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, M.; George, M.A.; Burger, A.; Collins, W.E.; Silberman, E. [Fisk Univ., Nashville, TN (United States)

    1993-03-01

    The study of the crystal surface morphology of CdZnTe is important for the understanding of the fundamentals of crystal growth in order to improve the crystal quality which is essential in applications such as substrates for epitaxy or performance of devices, i.e., room temperature nuclear spectrometers. We present a first atomic force microscopy study on CdZnTe. Cleaved (110) surfaces were imaged in the ambient and an atomic layer step structure was revealed. The effects of thermal annealing on the atomic steps together with Te precipitation along these steps are discussed in terms of deformation due to stress relief and the diffusion of tellurium precipitates. 12 refs., 3 figs.

  15. Size Design of CdZnTe Detector Shield for Measuring Burnup of Spent Fuel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>It is important to measure the burnup of spent fuel for nuclear safeguards, burnup credit and critical safety in spent-fuel reprocessing process. The purpose of this work is designing a portable device to

  16. Nanomechanical behaviors of (110) and (111) CdZnTe crystals investigated by nanoindentation

    Institute of Scientific and Technical Information of China (English)

    LI Yan; KANG Renke; GAO Hang; WANG Jinghe; LANG Yanju

    2009-01-01

    The nanomechanical behaviors of (110) and (111) CdZnTe crystals were investigated by nanoindentation. It was found that the indenter tip was adhered by the removed materials in scanning testing area although the scanning force on the tested surface was very small (1000 nN), which would affect the testing result of nanoindentation, so the indenter was clean before nanoindentation test. The experimemtal results showed that the hardness and Young's modulus decreased with the increase of indentation loads on the same plane. Because of the anisot-ropy of the CdZnTe crystal, the average hardness of (110) plane is 35% lower than that of (l 11 ) plane, and there are about 30% difference of the hardness along different crystallographic directions on the same plane. The hardness in 0° and 120° testing directions was the same due to the threefold symmetry of a Berkovich indenter. And the anisotropy affected the surface quality during machining of CdZnTe crystal.

  17. CZT nanoRAIDER_VFG Factsheet

    Energy Technology Data Exchange (ETDEWEB)

    James, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bolotnikov, A. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Yonggang [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-01-15

    Brookhaven National Laboratory (BNL) is working with FLIR System Inc., the manufacturer of the nanoRAIDER, to design a handheld device based on a position-sensitive virtual Frisch-grid (VFG) Cadmium-Zinc-Telluride (CdZnTe or CZT) detector array (with 1% or better energy resolution). The new device called nanoRAIDER VFG will be an improvement to the current nanoRAIDER, which is a compact gamma-ray detection instrument manufactured by FLIR Systems Inc. that employs relatively lower-performing CZT hemispheric detectors (i.e., 3%-FWHM CZT detectors). The nanoRAIDER will significantly improve the accuracy while maintaining similar efficiency, as compared to the nanoRAIDER, for in-field analysis of nuclear materials and detection of undeclared activities during inspections conducted by the International Atomic Energy Agency (IAEA). Since the nanoRAIDER is currently used by the IAEA as part of its Complementary Access toolkit, a relatively quick acceptance of the nanoRAIDER VFG for safeguards is anticipated. The nanoRAIDER VFG will help address several items listed in the IAEA’s Long-Term R&D Plan that could enhance the abilities to detect undeclared nuclear material and activities.

  18. Cross-Sectional Study of Macrodefects in MBE Dual-Band HgCdTe on CdZnTe

    Science.gov (United States)

    Reddy, M.; Lofgreen, D. D.; Jones, K. A.; Peterson, J. M.; Radford, W. A.; Benson, J. D.; Johnson, S. M.

    2013-11-01

    HgCdTe dual-band mid-wave infrared/long-wave infrared focal-plane arrays on CdZnTe are a key component in advanced electrooptic sensor applications. Molecular beam epitaxy (MBE) has been used successfully for growth of dual-band layers on larger CdZnTe substrates. However, the macrodefect density, which is known to reduce the pixel operability and its run-to-run variation, is larger when compared with layers grown on Si substrate. This paper reports the macrodefect density versus size signature of a well-optimized MBE dual-band growth and a cross-sectional study of a macrodefect that represents the most prevalent class using focused ion beam, scanning transmission electron microscopy, and energy-dispersive x-ray spectroscopy. The results show that the macrodefect originates from a void, which in turn is associated with a pit on the CdZnTe substrate.

  19. Zinc segregation in CdZnTe grown under Cd/Zn partial pressure control

    Science.gov (United States)

    Azoulay, M.; Rotter, S.; Gafni, G.; Tenne, R.; Roth, M.

    1992-02-01

    CdZnTe crystals have been grown by the modified vertical gradient freeze (VGF) method. Growth atmosphere control has been introduced to compensate for the Zn depletion in the melt during solidification. The axial Zn concentration in the grown crystals is found to be uniform within ±3%, as evaluated by X-ray diffraction and electron microprobe analysis. The radial segregation of Zn is minimal and does not exceed the experimental error due to the nearly planar interface achieved. Zinc microsegregation has been studied as well and is discussed in terms of the temporal variations of the solute concentration at the growth interface.

  20. Measurements on semiconductor and scintillator detectors at the Advanced Light Source (Conference Presentation)

    Science.gov (United States)

    Camarda, Giuseppe S.; Bolotnikov, Aleksey E.; Cui, Yonggang; Gul, Rubi; Hossain, Anwar; Roy, Utpal N.; Yang, Ge; James, Ralph B.; Vanier, Peter E.

    2016-09-01

    During the transition period between closure of Beamline X27B at BNL's NSLS and the opening of Beamline MID at NSLS-II, we began operation of LBNL's ALS Beamline 3.3.2 to carry out our radiation detection materials RD. Measurements performed at this Beamline include, X-ray Detector Response Mapping and White Beam X-ray Diffraction Topography (WBXDT), among others. We will introduce the capabilities of the Beamline and present the most recent results obtained on CdZnTe and scintillators. The goal of the studies on CdZnTe is to understand the origin and effects of subgrain boundaries and help to visualize the presence of a higher concentration of impurities, which might be responsible for the deterioration of the energy resolution and response uniformity in the vicinity of the sub-grain boundaries. The results obtained in the second year of measurements will be presented.

  1. Characterization of CdZnTe after argon ion beam bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Bensalah, H., E-mail: hakima.bensalah@uam.es [Departamento de Fisica de Materiales, Laboratorio de Crecimiento de Cristales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Hortelano, V. [GdS-Optronlab Group, Departamento Fisica Materia Condensada, Universidad de Valladolid, Edificio I-D, Paseo de Belen 1, 47011 Valladolid (Spain); Plaza, J.L. [Departamento de Fisica de Materiales, Laboratorio de Crecimiento de Cristales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Martinez, O. [GdS-Optronlab Group, Departamento Fisica Materia Condensada, Universidad de Valladolid, Edificio I-D, Paseo de Belen 1, 47011 Valladolid (Spain); Crocco, J.; Zheng, Q.; Carcelen, V.; Dieguez, E. [Departamento de Fisica de Materiales, Laboratorio de Crecimiento de Cristales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer After argon irradiation using low fluence, the defects on surface were removed. Black-Right-Pointing-Pointer The PL intensity increases after irradiation. This increase should be related to the improved quality of the CdZnTe surfaces. Black-Right-Pointing-Pointer Irradiation process lead to an elimination of Te precipitates from the surfaces of the CdZnTe samples. - Abstract: The objective of this work is to analyze the effects of argon ion irradiation process on the structure and distribution of Te inclusions in Cd{sub 1-x}Zn{sub x}Te crystals. The samples were treated with different ion fluences ranging from 2 to 8 Multiplication-Sign 10{sup 17} cm{sup -2}. The state of the samples before and after irradiation were studied by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Cathodoluminescence, Photoluminescence, and micro-Raman spectroscopy. The effect of the irradiation on the surface of the samples was clearly observed by SEM or AFM. Even for small fluences a removal of polishing scratches on the sample surfaces was observed. Likely correlated to this effect, an important enhancement in the luminescence intensity of the irradiated samples was observed. An aggregation effect of the Te inclusions seems to occur due to the Ar bombardment, which are also eliminated from the surfaces for the highest ion fluences used.

  2. Development of the ProtoEXIST2 advanced CZT detector plane

    OpenAIRE

    Allen, Branden; Hong, JaeSub; Grindlay, Jonathan; Burke, Michael; Barthelmy, Scott; Baker, Robert; Harrison, Fiona; Mao, Peter; Cook, William

    2011-01-01

    The ProtoEXIST program was conceived for the development of a highly scalable detector plane architecture utilizing pixilated CdZnTe (CZT) detectors for eventual deployment in a large scale (1-4 m2 active area) coded aperture X-ray telescope. Development is now underway for ProtoEXIST2, which ultimately will be comprised of a closely tiled 8×8 array of 19.9 mm × 19.9 mm, 5 mm thick Redlen CZT crystals, analogous to ProtoEXIST1, but will now utilize the NuASIC which accommodates the direct bon...

  3. An investigation of performance characteristics of a pixellated room-temperature semiconductor detector for medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, P; Santos, A [Centro de Investigacion Biomedica de Bioningenieria, Biomateriales y Nanomedicina, CEEI-Modulo 3, C/ Maria de Luna, 11, 50018 Zaragoza (United States); Darambara, D G, E-mail: pguerra@ciber-bbn.e [Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Fulham Road, London SW3 6JJ (United Kingdom)

    2009-09-07

    The operation of any semiconductor detector depends on the movement of the charge carriers, which are created within the material when radiation passes through, as a result of energy deposition. The carrier movement in the bulk semiconductor induces charges on the metal electrodes, and therefore a current on the electrodes and the external circuit. The induced charge strongly depends on the material transport parameters as well as the geometrical dimensions of a pixellated semiconductor detector. This work focuses on the performance optimization in terms of energy resolution, detection efficiency and intrinsic spatial resolution of a room-temperature semiconductor pixellated detector based on CdTe/CdZnTe. It analyses and inter-relates these performance figures for various dimensions of CdTe and CdZnTe detectors and for an energy range spanning from x-ray (25 keV) to PET (511 keV) imaging. Monte Carlo simulations, which integrate a detailed and accurate noise model, are carried out to investigate several CdTe/CdZnTe configurations and to determine possible design specifications. Under the considered conditions, the simulations demonstrate the superiority of the CdZnTe over the CdTe in terms of energy resolution and sensitivity in the photopeak. Further, according to the results, the spatial resolution is maximized at high energies and the energy resolution at low energies, while a reasonable detection efficiency is achieved at high energies, with a 1 x 1 x 6 mm{sup 3} CdZnTe pixellated detector.

  4. CMOS Pixel Spectroscopic Circuits for Cd(ZnTe Gamma Ray Imagers

    Directory of Open Access Journals (Sweden)

    Hatzistratis D.

    2016-01-01

    Full Text Available A family of 2-D pixel CMOS ASICs have been developed to be used as readout electronics of gamma ray imaging instruments based on hybrid pixel sensor arrays. One element of the sensor array consists of a pixilated single crystal of CdTe or CdZnTe semiconductor bump bonded to the CMOS electronic circuit. The first member of the family can process single photon signals which deliver up to 4fCb charge, while the two other can process signals up to 36fCb. A unique readout mode and the simultaneous extraction of energy and time tagging information of the converted photons differentiate the members of this family from other existing CMOS readout circuits.

  5. The crystalline quality distribution in CdZnTe single crystal correlated to the interface shape during growth

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, M.; Rotter, S.; Gafni, G. (Soreq Nuclear Research Center, Yavne (Israel)); Roth, M. (School of Applied Science and Technology, Hebrew Univ. of Jerusalem (Israel))

    1992-02-01

    Crystalline quality of CdZnTe single crystals grown by the vertical gradient freeze (VGF) method has been evaluated using the double crystal rocking curve (DCRC) analysis and etch pits density (EPD) measurements. The full width at half maximum (HWHM) values of the DCRCs vary within 40% while the EPD values range from 2 to 8 x 10{sup 4} cm{sup -2} along the crystal growth axis. Best results are obtained for the central part of the crystals, where the growth interface exhibits a nearly planar shape. The results obtained have been used for practical implications with regard to the use of CdZnTe crystals as a substrate material for HgCdTe thin films growth. (orig.).

  6. Effect of thickness on physical properties of electron beam vacuum evaporated CdZnTe thin films for tandem solar cells

    Science.gov (United States)

    Chander, Subhash; Dhaka, M. S.

    2016-10-01

    The thickness and physical properties of electron beam vacuum evaporated CdZnTe thin films have been optimized in the present work. The films of thickness 300 nm and 400 nm were deposited on ITO coated glass substrates and subjected to different characterization tools like X-ray diffraction (XRD), UV-Vis spectrophotometer, source meter and scanning electron microscopy (SEM) to investigate the structural, optical, electrical and surface morphological properties respectively. The XRD results show that the as-deposited CdZnTe thin films have zinc blende cubic structure and polycrystalline in nature with preferred orientation (111). Different structural parameters are also evaluated and discussed. The optical study reveals that the optical transition is found to be direct and energy band gap is decreased for higher thickness. The transmittance is found to increase with thickness and red shift observed which is suitable for CdZnTe films as an absorber layer in tandem solar cells. The current-voltage characteristics of deposited films show linear behavior in both forward and reverse directions as well as the conductivity is increased for higher film thickness. The SEM studies show that the as-deposited CdZnTe thin films are found to be homogeneous, uniform, small circle-shaped grains and free from crystal defects. The experimental results confirm that the film thickness plays an important role to optimize the physical properties of CdZnTe thin films for tandem solar cell applications as an absorber layer.

  7. Application of a CZT detector to in situ environmental radioactivity measurement in the Fukushima area.

    Science.gov (United States)

    Kowatari, M; Kubota, T; Shibahara, Y; Fujii, T; Fukutani, S; Takamiya, K; Mizuno, S; Yamana, H

    2015-11-01

    Instead of conventional Ge semiconductor detectors and NaI(Tl) scintillation spectrometers, an application of a CdZnTe semiconductor (CZT) whose crystal has the dimension of 1 cm cubic to the in situ environmental radioactivity measurement was attempted in deeply affected areas in Fukushima region. Results of deposition density on soil for (134)Cs/(137)Cs obtained seemed consistent, comparing obtained results with those measured by the Japanese government. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. A pixellated gamma-camera based on CdTe detectors clinical interests and performances

    CERN Document Server

    Chambron, J; Eclancher, B; Scheiber, C; Siffert, P; Hage-Ali, M; Regal, R; Kazandjian, A; Prat, V; Thomas, S; Warren, S; Matz, R; Jahnke, A; Karman, M; Pszota, A; Németh, L

    2000-01-01

    A mobile gamma camera dedicated to nuclear cardiology, based on a 15 cmx15 cm detection matrix of 2304 CdTe detector elements, 2.83 mmx2.83 mmx2 mm, has been developed with a European Community support to academic and industrial research centres. The intrinsic properties of the semiconductor crystals - low-ionisation energy, high-energy resolution, high attenuation coefficient - are potentially attractive to improve the gamma-camera performances. But their use as gamma detectors for medical imaging at high resolution requires production of high-grade materials and large quantities of sophisticated read-out electronics. The decision was taken to use CdTe rather than CdZnTe, because the manufacturer (Eurorad, France) has a large experience for producing high-grade materials, with a good homogeneity and stability and whose transport properties, characterised by the mobility-lifetime product, are at least 5 times greater than that of CdZnTe. The detector matrix is divided in 9 square units, each unit is composed ...

  9. Optimization of control parameters of CdZnTe ACRT-Bridgman single crystal growth

    Institute of Scientific and Technical Information of China (English)

    LIU Juncheng

    2004-01-01

    The CdZnTe vertical Bridgman single crystal process with accelerated crucible rotation technique (ACRT) has been simulated. Effects have been investigated of the ACRT wave parameters on the solid-liquid interface concavity and the solute segregation of the crystal. The results show that ACRT can result in the increase of both the solid-liquid interface concavity and the temperature gradient of the melt in the front of the solid-liquid interface, of which the magnitude varies from small to many times when the ACRT wave parameters change. Of the ACRT wave parameters, the increase of the crucible maximum rotation rate can hardly improve the radial solute segregation of the crystal, but the variation of the crucible acceleration time, the keep time at the maximum rotation rate, and the crucible deceleration time can affect the solute segregation of the single crystal extraordinarily. With suitable wave parameters, ACRT greatly decreases the radial solute segregation of the crystal, and even makes it disappear completely. However, it increases both the axial solute segregation and the radial one notably with bad wave parameters. An excellent single crystal could be gotten, of which a majority part is with no segregation, with ACRT-Bridgman method by adjusting both the ACRT wave parameters and the crystal growth control parameters, such as the initial temperature of the melt, the temperature gradient, and the crucible withdrawal rate, etc.

  10. Growth and characterization of CdTe and CdZnTe crystals for substrate application

    Science.gov (United States)

    Azoulay, Moshe; Zilber, Raphael; Shusterman, Sergy; Goldgirsh, Alex; Zontag, Itzhak

    2003-01-01

    During the last decade we have investigated the synthesis, growth and characterization of CdTe and CdZnTe semiconductor compounds. As a result, substrate crystals, suitable for mercury cadmium telluride thin film growth are prepared. The emphasis will be given to the investigation of the thermal regime during growth, reflected at the solid liquid interface shape and its influence on the crystalline quality. Seeded and unseeded growth experiments are compared in terms of structural crystalline quality. Seeded and unseeded growth experiments are compared in terms of structural crystalline perfection as well as single crystal yield. The effect of thermal annealing on IR transmittance, precipitates and inclusions will be discussed in detail. Moreover, we will show the recent new trends for simulation of crystal growth processes by CRYSVUN software as well as practical implementation of calculated data for the grwoth of II-VI crystals. Preliminary study on the vapor phase control during growth and crystal cooling procedures will also be discussed.

  11. Background measurements from balloon-born imaging CZT detectors

    Science.gov (United States)

    Jenkins, Jonathan A.; Narita, Tomohiko; Grindlay, Jonathan E.; Bloser, Peter F.; Stahle, Carl M.; Parker, Bradford H.; Barthelmy, Scott D.

    2003-03-01

    We report detector characteristics and background measurements from two prototype imaging CdZnTe (CZT) detectors flown on a scientific balloon payload in May 2001. The detectors are both platinum-contact 10 mm × 10 mm × 5 mm CZT crystals, each with a 4 × 4 array of pixels tiling the anode. One is made from IMARAD horizontal Bridgman CZT, the other from eV Products high-pressure Bridgman CZT. Both detectors were mounted side-by-side in a flip-chip configuration and read out by a 32-channel IDE VA/TA ASIC preamp/shaper. We enclosed the detectors in the same 40o field-of-view collimator used in our previously-reported September 2000 flight. I-V curves for the detectors are diode-like, and we find that the platinum contacts adhere significantly better to the CZT surfaces than gold to previosu detectors. The detectors and instrumentation performed well in a 20-hour balloon flight on 23/24 May 2001. Although we discovered a significant instrumental background component in flight, it was possible to measure and subtract this component from the spectra. The resulting IMARAD detector background spectrum reaches ~5×10-3 counts cm-2s-1keV-1 at 100 keV and has a power-law index of ~2 at hgih energies. The eV Products detector has a similar spectrum, although there is more uncertainty in the enregy scale because of calibration complications.

  12. Electrical properties of Au/CdZnTe/Au detectors grown by the boron oxide encapsulated Vertical Bridgman technique

    Energy Technology Data Exchange (ETDEWEB)

    Turturici, A.A. [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy); Abbene, L., E-mail: leonardo.abbene@unipa.it [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy); Gerardi, G. [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy); Benassi, G. [due2lab s.r.l., Via Paolo Borsellino 2, Scandiano, 42019 Reggio Emilia (Italy); Bettelli, M.; Calestani, D. [IMEM/CNR, Parco Area delle Scienze 37/A, Parma 43100 (Italy); Zambelli, N. [due2lab s.r.l., Via Paolo Borsellino 2, Scandiano, 42019 Reggio Emilia (Italy); Raso, G. [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy); Zappettini, A. [IMEM/CNR, Parco Area delle Scienze 37/A, Parma 43100 (Italy); Principato, F. [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, Palermo 90128 (Italy)

    2016-09-11

    In this work we report on the results of electrical characterization of new CdZnTe detectors grown by the Boron oxide encapsulated Vertical Bridgman technique (B-VB), currently produced at IMEM-CNR (Parma, Italy). The detectors, with gold electroless contacts, have different thicknesses (1 and 2.5 mm) and the same electrode layout, characterized by a central anode surrounded by a guard-ring electrode. Investigations on the charge transport mechanisms and the electrical contact properties, through the modeling of the measured current–voltage (I–V) curves, were performed. Generally, the detectors are characterized by low leakage currents at high bias voltages even at room temperature: 34 nA/cm{sup 2} (T=25 °C) at 10,000 V/cm, making them very attractive for high flux X-ray measurements, where high bias voltage operation is required. The Au/CdZnTe barrier heights of the devices were estimated by using the interfacial layer-thermionic-diffusion (ITD) model in the reverse bias voltage range. Comparisons with CdZnTe detectors, grown by Traveling Heater Method (THM) and characterized by the same electrode layout, deposition technique and resistivity, were also performed.

  13. Hg1-xCdxTe vapor deposition on CdZnTe substrates by Closed Space Sublimation technique

    Science.gov (United States)

    Rubio, Sandra; Sochinskii, Nikolai V.; Repiso, Eva; Tsybrii, Zinoviia; Sizov, Fiodor; Plaza, Jose Luis; Diéguez, Ernesto

    2017-01-01

    Closed Space Sublimation (CSS) technique has been studied to deposit Hg1-xCdxTe polycrystalline films on CdZnTe substrates at the improved pressure-temperature conditions. The experimental results on film characterization suggest that the CSS optimal conditions are the argon atmospheric pressure (1013 mbar) and the deposition temperature in the range of 500-550 °C. These conditions provide macro-defect free Hg1-xCdxTe films with the uniform size and surface distribution of polycrystals.

  14. Development and characterization of scintillation based detectors for the use in radiological early warning networks

    Science.gov (United States)

    Kessler, P.; Dombrowski, H.; Neumaier, S.

    2016-02-01

    To detect radiological incidents, all members of the European Union have installed nationwide radiological early warning networks. Most of the installed detector systems supply only dosimetric information. Novel spectrometry systems are considered to be good candidates for a new detector generation for environmental radiation monitoring because they will supply both nuclide-specific information and ambient dose equivalent rate values. Four different detector types were chosen and compared with each other (LaBr3, CeBr3, SrI2 scintillation detectors, and CdZnTe, a semiconductor detector). As a first step, the inherent background of these detectors was measured in the low background underground laboratory UDO II of PTB. As a second step, the relative detection sensitivity between the various detectors was determined at different energies. Finally, the detectors were exposed to a 4π-radiation field of radon progeny in PTB's radon chamber. The obtained results show that the investigated detectors are well suited for environmental radiation monitoring.

  15. 载流子输运性能对CdZnTe晶体脉冲X射线响应特性的影响∗%Effects of charge carrier behaviors on the time response of CdZnTe crystals irradiated by pulsed X-rays

    Institute of Scientific and Technical Information of China (English)

    徐亚东; 王昌盛; 谷亚旭; 郭榕榕; 苏春磊; 介万奇

    2014-01-01

    采用生长态高电阻 CdZnTe 晶体制备出平面电极探测器,室温下测试了其在脉冲 X射线作用下的诱导电流曲线.分析了脉冲电流的上升时间以及脉冲衰减过程,发现脉冲上升时间约为2 ns,且不受外加偏压影响,而脉冲衰减过程可分为3阶段.利用α粒子结合飞行时间技术研究了 CdZnTe 晶体的载流子传输特性,分析了结构缺陷的散射和俘获-佉俘获对载流子传输特性的影响.同时对比了不同厚度的 CdZnTe探测器在不同电压下对脉冲 X 射线的响应特性.结果表明,当外加电场强度增加时,诱导脉冲电流曲线的半峰宽呈指数衰减,但当探测器厚度大于0.2 mm 时,随着探测器厚度的增加变化不明显.可能是由于材料中结构缺陷的浓度增加,对载流子的俘获和散射作用加剧,严重影响了载流子的传输过程和复合时间.%As-grown high resistive CdZnTe crystals were employed to fabricate planar detectors.The pulsed X-rays induced transient current waveforms were obtained at room temperature.The rise time and decay time of the transient currents were evaluated.The rise time is approximately of 2 ns,which is independent on the bias voltage.The current decay can be divided into 3 parts.The charge transport behaviors were analyzed usingαparticles induced pulses combining with time of flight technique.The effects of structure defects on the charge carrier scattering and trapping-detrapping were discussed.In addition,the transient current waveforms of CdZnTe detectors with different thickness were compared as a function of bias voltage.The full wave at half maximum (FWHM)of the transient currents is exponential decay as the bias increases.However,the variation is limited when the detector is thicker than 0.2 mm,which is possibly attributed to the increasing trapping and scattering centers in the materials.Thus,the charge transport properties were degraded and the recombination time was prolonged.

  16. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  17. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  18. Preliminary test of an imaging probe for nuclear medicine using hybrid pixel detectors

    CERN Document Server

    Bertolucci, Ennio; Mettivier, G; Montesi, M C; Russo, P

    2002-01-01

    We are investigating the feasibility of an intraoperative imaging probe for lymphoscintigraphy with Tc-99m tracer, for sentinel node radioguided surgery, using the Medipix series of hybrid detectors coupled to a collimator. These detectors are pixelated semiconductor detectors bump-bonded to the Medipix1 photon counting read-out chip (64x64 pixel, 170 mu m pitch) or to the Medipix2 chip (256x256 pixel, 55 mu m pitch), developed by the European Medipix collaboration. The pixel detector we plan to use in the final version of the probe is a semi-insulating GaAs detector or a 1-2 mm thick CdZnTe detector. For the preliminary tests presented here, we used 300-mu m thick silicon detectors, hybridized via bump-bonding to the Medipix1 chip. We used a tungsten parallel-hole collimator (7 mm thick, matrix array of 64x64 100 mu m circular holes with 170 mu m pitch), and a 22, 60 and 122 keV point-like (1 mm diameter) radioactive sources, placed at various distances from the detector. These tests were conducted in order ...

  19. Synchrotron study of charge transport in a CZT ring-drift detector

    Energy Technology Data Exchange (ETDEWEB)

    Hartog, Roland den, E-mail: r.h.den.hartog@sron.nl [High-Energy Astrophysics division of SRON, The Netherlands Institute of Space Research, Sorbonnelaan 2, 3584 CA, Utrecht (Netherlands); Owens, A., E-mail: aowens@rssd.esa.int [Science Projects Department of the European Space Agency, at ESTEC, P.O. Box 299, 2200 AG, Noordwijk (Netherlands); Kozorezov, A.G., E-mail: a.kozorezov@lancaster.ac.uk [Department of Physics of the University of Lancaster (United Kingdom); Wigmore, J.K. [Department of Physics of the University of Lancaster (United Kingdom); Gostilo, V., E-mail: office@bruker-baltic.lv [Bruker Baltic SAI, Ganibudambis 26, P.O. Box 33, Riga, LV-1005 (Latvia); Webb, M.A. [Hamburger Synchrotronstrahlungslabor HASYLAB at the Deutsches Elektronen-Synchrotron DESY, Notke-Strasse 85, D-22603, Hamburg (Germany)

    2011-08-21

    We report on experimental and theoretical results obtained with a CdZnTe (CZT) detector with a versatile read-out scheme: the ring detector. This detector has been tested extensively both in our laboratories and at the HASYLAB synchrotron facility and has demonstrated excellent energy resolution of up to 0.73%, over a wide dynamic range covering 6-662 keV. The key feature in this design is carefully managed charge transport, which eliminates the hole contribution, and optimizes the electron collection. We have developed a theoretical model of this detector, to enable the optimization of the read-out structure as a function of detector dimensions. A comparison between X-ray scans across the detector and model calculations shows that the model already captures all the major detector features, but still leaves a few challenging questions related to CZT surface conductivity. A defect in the detector, which breaks the expected cylindrical symmetry of the charge transport, is examined in detail by differential spectrometry, a powerful technique, which exploits differences in X-ray absorption between bulk and defect.

  20. Optimizing timing performance of CdTe detectors for PET

    Science.gov (United States)

    Nakhostin, M.

    2017-10-01

    Despite several attractive properties, the poor timing performance of compound semiconductor detectors such as CdTe and CdZnTe has hindered their use in commercial PET imaging systems. The standard method of pulse timing with such detectors is to employ a constant-fraction discriminator at the output of a timing filter which is fed by the pulses from a charge-sensitive preamplifier. The method has led to a time resolution of about 10 ns at full-width at half-maximum (FWHM) with 1 mm thick CdTe detectors. This paper presents a detailed investigation on the parameters limiting the timing performance of Ohmic contact planar CdTe detectors with the standard pulse timing method. The jitter and time-walk errors are studied through simulation and experimental measurements and it is revealed that the best timing results obtained with the standard timing method suffer from a significant loss of coincidence events (~50%). In order to improve the performance of the detectors with full detection efficiency, a new digital pulse timing method based on a simple pattern recognition technique was developed. A time resolution of 3.29  ±  0.10 ns (FWHM) in the energy range of 300–650 keV was achieved with an Ohmic contact planar CdTe detector (5  ×  5  ×  1 mm3). The digital pulse processing method was also used to correct for the charge-trapping effect and an improvement in the energy resolution from 4.83  ±  0.66% to 2.780  ±  0.002% (FWHM) at 511 keV was achieved. Further improvement of time resolution through a moderate cooling of the detector and the application of the method to other detector structures are also discussed.

  1. Gaseous Detectors: Charged Particle Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Hilke, H J

    2011-01-01

    Gaseous Detectors in 'Charged Particle Detectors - 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 Subsection '3.1.2 Gaseous Detectors' of Section '3.1 Charged Particle Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.1.2 Gaseous Detectors 3.1.2.1 Introduction 3.1.2.2 Basic Processes 3.1.2.2.1 Gas ionization by charged particles 3.1.2.2.1.1 Primary clusters 3.1.2.2.1.2 Cluster size distribution 3.1.2.2.1.3 Total number of ion pairs 3.1.2.2.1.4 Dependence of energy deposit on particle velocity 3.1.2.2.2 Transport of...

  2. 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...

  3. Performance characteristics of CdTe drift ring detector

    Science.gov (United States)

    Alruhaili, A.; Sellin, P. J.; Lohstroh, A.; Veeramani, P.; Kazemi, S.; Veale, M. C.; Sawhney, K. J. S.; Kachkanov, V.

    2014-03-01

    CdTe and CdZnTe material is an excellent candidate for the fabrication of high energy X-ray spectroscopic detectors due to their good quantum efficiency and room temperature operation. The main material limitation is associated with the poor charge transport properties of holes. The motivation of this work is to investigate the performance characteristics of a detector fabricated with a drift ring geometry that is insensitive to the transport of holes. The performance of a prototype Ohmic CdTe drift ring detector fabricated by Acrorad with 3 drift rings is reported; measurements include room temperature current voltage characteristics (IV) and spectroscopic performance. The data shows that the energy resolution of the detector is limited by leakage current which is a combination of bulk and surface leakage currents. The energy resolution was studied as a function of incident X-ray position with an X-ray microbeam at the Diamond Light Source. Different ring biasing schemes were investigated and the results show that by increasing the lateral field (i.e. the bias gradient across the rings) the active area, evaluated by the detected count rate, increased significantly.

  4. Semiconductor detectors for soft γ-ray astrophysics

    Science.gov (United States)

    Lebrun, François

    2006-07-01

    The study of γ-ray bursts, compact objects, nucleosynthesis and supernova remnants triggers the most interest today in the soft γ-ray domain. These topics have various experimental requirements with emphasis either on imaging or on spectroscopy. Recent progress has shown the great potential of semiconductor detectors for both applications at the expense of classical scintillators such as NaI or CsI. They also gave insight into their long-term in-orbit behaviour. Room temperature semiconductor detectors, particularly CdTe and CdZnTe, are confirmed as the best choice for imaging applications. As illustrated by the INTEGRAL/ISGRI camera, the CdTe stability is better than expected; its internal background is comparable to that of scintillators, and the spectroscopic degradation in space is slow with a lifetime of about 40 years on an eccentric orbit. Cooled germanium detectors offer the best energy resolution but degrade more rapidly under the cosmic-ray irradiation. However, the INTEGRAL/SPI spectrometer has demonstrated that periodic in-orbit annealings, allowing for a full recovery of the energy resolution, can maintain the spectroscopic performance over several years. Most future projects, focussing on coded mask or Compton telescopes, will take advantage of the semiconductor technology, particularly that related to the ambient temperature detectors.

  5. Laboratory tests on neutron shields for gamma-ray detectors in space

    CERN Document Server

    Hong, J; Hailey, C J

    2000-01-01

    Shields capable of suppressing neutron-induced background in new classes of gamma-ray detectors such as CdZnTe are becoming important for a variety of reasons. These include a high cross section for neutron interactions in new classes of detector materials as well as the inefficient vetoing of neutron-induced background in conventional active shields. We have previously demonstrated through Monte-Carlo simulations how our new approach, supershields, is superior to the monolithic, bi-atomic neutron shields which have been developed in the past. We report here on the first prototype models for supershields based on boron and hydrogen. We verify the performance of these supershields through laboratory experiments. These experimental results, as well as measurements of conventional monolithic neutron shields, are shown to be consistent with Monte-Carlo simulations. We discuss the implications of this experiment for designs of supershields in general and their application to future hard X-ray/gamma-ray experiments...

  6. Te Inclusions in CZT Detectors: New Method for Correcting Their Adverse Effects

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, A.E.; Babalola, S.; Camarda, G.S.; Cui, Y.; Egarievwe, S.U.; Hawrami, R.; Hossain, A.; Yang, G.; James, R.B.

    2009-10-25

    Both Te inclusions and point defects can trap the charge carriers generated by ionizing particles in CdZnTe (CZT) detectors. The amount of charge trapped by point defects is proportional to the carriers’ drift time and can be corrected electronically. In the case of Te inclusions, the charge loss depends upon their random locations with respect to the electron cloud. Consequently, inclusions introduce fluctuations in the charge signals, which cannot be easily corrected. In this paper, we describe direct measurements of the cumulative effect of Te inclusions and its influence on the response of CZT detectors of different thicknesses and different sizes and concentrations of Te inclusions. We also discuss a means of partially correcting their adverse effects.

  7. Pixel Detectors

    OpenAIRE

    Wermes, Norbert

    2005-01-01

    Pixel detectors for precise particle tracking in high energy physics have been developed to a level of maturity during the past decade. Three of the LHC detectors will use vertex detectors close to the interaction point based on the hybrid pixel technology which can be considered the state of the art in this field of instrumentation. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as the very harsh...

  8. Study of Morphological Defects on Dual-Band HgCdTe on CdZnTe

    Science.gov (United States)

    Reddy, M.; Radford, W. A.; Lofgreen, D. D.; Olsson, K. R.; Peterson, J. M.; Johnson, S. M.

    2014-08-01

    HgCdTe dual-band epitaxial layers on lattice-matched CdZnTe substrates often have morphological defects. These defects, unlike normal void and microvoid defects, do not contain a polycrystalline core and, therefore, do not offer a good contrast for observation using optical and electron microscopes. This paper reports a way of identifying these defects by using a Nomarski optical microscopy image overlay on focused ion beam microscopy images for preparation of thin cross-sectional foils of these defects. Transmission electron microscopy was used to study the defect cross-sections to identify the origin and evolution of the morphological defects and their effect on the epitaxial layer. This paper reports cross-sectional analysis of four morphological defects of different shape and size.

  9. Growth by the Multi-tube Physical Vapour Transport method and characterisation of bulk (Cd,Zn)Te

    Science.gov (United States)

    Choubey, A.; Veeramani, P.; Pym, A. T. G.; Mullins, J. T.; Sellin, P. J.; Brinkman, A. W.; Radley, I.; Basu, A.; Tanner, B. K.

    2012-08-01

    Growth by the Multi-tube Physical Vapour Transport technique and characterisation of bulk (Cd,Zn)Te is described. The crystalline perfection and uniformity of zinc content have been mapped by infra-red transmission and microscopy, X-ray diffraction and photoluminescence. X-ray double crystal rocking curve full widths at half maximum as low as 43 in have been obtained and a mean zinc mole fraction of 0.03 has been found to vary by less than ±0.003 over the diameter of a 50 mm boule. The material exhibits a resistivity in the 2×109Ω cm range and planar devices fabricated from this material have shown electron mobility lifetime products of 4.07×10-3 cm2 V-1.

  10. Polarimetric analysis of a CdZnTe spectro-imager under multi-pixel irradiation conditions

    Science.gov (United States)

    Pinto, M.; da Silva, R. M. Curado; Maia, J. M.; Simões, N.; Marques, J.; Pereira, L.; Trindade, A. M. F.; Caroli, E.; Auricchio, N.; Stephen, J. B.; Gonçalves, P.

    2016-12-01

    So far, polarimetry in high-energy astrophysics has been insufficiently explored due to the complexity of the required detection, electronic and signal processing systems. However, its importance is today largely recognized by the astrophysical community, therefore the next generation of high-energy space instruments will certainly provide polarimetric observations, contemporaneously with spectroscopy and imaging. We have been participating in high-energy observatory proposals submitted to ESA Cosmic Vision calls, such as GRI (Gamma-Ray Imager), DUAL and ASTROGAM, where the main instrument was a spectro-imager with polarimetric capabilities. More recently, the H2020 AHEAD project was launched with the objective to promote more coherent and mature future high-energy space mission proposals. In this context of high-energy proposal development, we have tested a CdZnTe detection plane prototype polarimeter under a partially polarized gamma-ray beam generated from an aluminum target irradiated by a 22Na (511 keV) radioactive source. The polarized beam cross section was 1 cm2, allowing the irradiation of a wide multi-pixelated area where all the pixels operate simultaneously as a scatterer and as an absorber. The methods implemented to analyze such multi-pixel irradiation are similar to those required to analyze a spectro-imager polarimeter operating in space, since celestial source photons should irradiate its full pixilated area. Correction methods to mitigate systematic errors inherent to CdZnTe and to the experimental conditions were also implemented. The polarization level ( 40%) and the polarization angle (precision of ±5° up to ±9°) obtained under multi-pixel irradiation conditions are presented and compared with simulated data.

  11. Metal Detectors.

    Science.gov (United States)

    Harrington-Lueker, Donna

    1992-01-01

    Schools that count on metal detectors to stem the flow of weapons into the schools create a false sense of security. Recommendations include investing in personnel rather than hardware, cultivating the confidence of law-abiding students, and enforcing discipline. Metal detectors can be quite effective at afterschool events. (MLF)

  12. Optical Detectors

    Science.gov (United States)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  13. Preparation of Cd(Zn)Te and CuInSe sub 2 films and devices by a two-stage process

    Energy Technology Data Exchange (ETDEWEB)

    Basol, B.M.; Kapur, V.K. (International Solar Electric Technology (ISET), Inglewood, CA (USA))

    1991-05-01

    The two-stage process was used to prepare thin films of Cd(Zn)Te and CuInSe{sub 2}. The technique involves first depositing the elemental components of the compound onto a substrate in the form of thin stacked layers and then reacting these elemental components to obtain a thin film of the desired compound. While CdTe films grown on thin CdS layers have uniform stoichiometries and sharp interfaces with the underlying CdS layers, CdZnTe films deposited onto similar substrates give rise to diffused CdZnTe-CdS interfaces because of the reactive nature of zinc. In CuInSe{sub 2} processing, the nature of the reacted compound film strongly depends on the nature of the Cu-In layers. CdS/CuInSe{sub 2} device efficiencies are also influenced by the method of deposition for the CdS window layers. (orig.).

  14. DUMAND detector

    CERN Multimedia

    This object is one of the 256 other detectors of the DUMAND (Deep Underwater Muon And Neutrino Detection) experiment. The goal of the experiment was the construction of the first deep ocean high energy neutrino detector, to be placed at 4800 m depth in the Pacific Ocean off Keahole Point on the Big Island of Hawaii. A few years ago, a European conference with Cosmic experiments was organized at CERN as they were projects like DUMAND in Hawaii. Along with the conference, a temporary exhibition was organised as well. It was a collaboration of institutions from Germany, Japan, Switzerland and the U.S.A. CERN had borrowed equipment and objects from different institutes around the world, including this detector of the DUMAND experiment. Most of the equipment were sent back to the institutes, however this detector sphere was offered to a CERN member of the personnel.

  15. Spectrum reconstruction method based on the detector response model calibrated by x-ray fluorescence

    Science.gov (United States)

    Li, Ruizhe; Li, Liang; Chen, Zhiqiang

    2017-02-01

    Accurate estimation of distortion-free spectra is important but difficult in various applications, especially for spectral computed tomography. Two key problems must be solved to reconstruct the incident spectrum. One is the acquisition of the detector energy response. It can be calculated by Monte Carlo simulation, which requires detailed modeling of the detector system and a high computational power. It can also be acquired by establishing a parametric response model and be calibrated using monochromatic x-ray sources, such as synchrotron sources or radioactive isotopes. However, these monochromatic sources are difficult to obtain. Inspired by x-ray fluorescence (XRF) spectrum modeling, we propose a feasible method to obtain the detector energy response based on an optimized parametric model for CdZnTe or CdTe detectors. The other key problem is the reconstruction of the incident spectrum with the detector response. Directly obtaining an accurate solution from noisy data is difficult because the reconstruction problem is severely ill-posed. Different from the existing spectrum stripping method, a maximum likelihood-expectation maximization iterative algorithm is developed based on the Poisson noise model of the system. Simulation and experiment results show that our method is effective for spectrum reconstruction and markedly increases the accuracy of XRF spectra compared with the spectrum stripping method. The applicability of the proposed method is discussed, and promising results are presented.

  16. Calorimeter detectors

    CERN Document Server

    de Barbaro, P; The ATLAS collaboration

    2013-01-01

    Although the instantaneous and integrated luminosity in HL-LHC will be far higher than the LHC detectors were originally designed for, the Barrel calorimeters of the four experiments are expected to continue to perform well  throughout the Phase II program. The conditions for the End-Cap calorimeters are far more challenging and whilst some detectors will require relatively modest changes, others require far more substantial upgrades. We present the results of longevity and performance studies for the calorimeter systems of the four main LHC experiments and outline the upgrade options under consideration. We include a discussion of the R&D required to make the final technology choices for the upgraded detectors.

  17. Pixel detectors

    CERN Document Server

    Passmore, M S

    2001-01-01

    positions on the detector. The loss of secondary electrons follows the profile of the detector and increases with higher energy ions. studies of the spatial resolution predict a value of 5.3 lp/mm. The image noise in photon counting systems is investigated theoretically and experimentally and is shown to be given by Poisson statistics. The rate capability of the LAD1 was measured to be 250 kHz per pixel. Theoretical and experimental studies of the difference in contrast for ideal charge integrating and photon counting imaging systems were carried out. It is shown that the contrast differs and that for the conventional definition (contrast = (background - signal)/background) the photon counting device will, in some cases, always give a better contrast than the integrating system. Simulations in MEDICI are combined with analytical calculations to investigate charge collection efficiencies (CCE) in semiconductor detectors. Different pixel sizes and biasing conditions are considered. The results show charge shari...

  18. X and {gamma}-Ray imaging CdTe/CdZnTe detectors. From material to imaging; Imagerie X et {gamma}. Detecteurs CdTe/CdZnTe. Du materiau a l'imageur

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This document presents the recent advances made by the Laboratory of electronics and computer science technologies (Leti) of the French atomic energy commission (CEA) in the domain of semiconductor detectors for X- and {gamma}-ray imaging systems. The new generation of detectors is based on the use of cadmium telluride CdTe or its compound CdZnTe, in association with integrated read-out electronics. The advantages of direct conversion for X-ray and {gamma}-ray detectors and the choice of CdTe is presented first. Then some applications of the CdTe detector are presented: high-energy X-ray tomograph for the control of radioactive waste drums, high definition X-ray imager for medical applications, high-energy X-ray imager for military simulation programs, {gamma}-ray imager for astrophysics applications, and a medical gamma camera to replace the standard Anger camera used in nuclear medicine. (J.S.)

  19. XMASS detector

    CERN Document Server

    Abe, K; Hiraide, K; Hirano, S; Kishimoto, Y; Kobayashi, K; Moriyama, S; Nakagawa, K; Nakahata, M; Nishiie, H; Ogawa, H; Oka, N; Sekiya, H; Shinozaki, A; Suzuki, Y; Takeda, A; Takachio, O; Ueshima, K; Umemoto, D; Yamashita, M; Yang, B S; Tasaka, S; Liu, J; Martens, K; Hosokawa, K; Miuchi, K; Murata, A; Onishi, Y; Otsuka, Y; Takeuchi, Y; Kim, Y H; Lee, K B; Lee, M K; Lee, J S; Fukuda, Y; Itow, Y; Nishitani, Y; Masuda, K; Takiya, H; Uchida, H; Kim, N Y; Kim, Y D; Kusaba, F; Motoki, D; Nishijima, K; Fujii, K; Murayama, I; Nakamura, S

    2013-01-01

    The XMASS project aims to detect dark matter, pp and $^{7}$Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  20. XMASS detector

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hieda, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Hiraide, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hirano, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kishimoto, Y.; Kobayashi, K.; Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nakagawa, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Ogawa, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); and others

    2013-07-11

    The XMASS project aims to detect dark matter, pp and {sup 7}Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  1. A pixellated γ-camera based on CdTe detectors clinical interests and performances

    Science.gov (United States)

    Chambron, J.; Arntz, Y.; Eclancher, B.; Scheiber, Ch; Siffert, P.; Hage Hali, M.; Regal, R.; Kazandjian, A.; Prat, V.; Thomas, S.; Warren, S.; Matz, R.; Jahnke, A.; Karman, M.; Pszota, A.; Nemeth, L.

    2000-07-01

    A mobile gamma camera dedicated to nuclear cardiology, based on a 15 cm×15 cm detection matrix of 2304 CdTe detector elements, 2.83 mm×2.83 mm×2 mm, has been developed with a European Community support to academic and industrial research centres. The intrinsic properties of the semiconductor crystals - low-ionisation energy, high-energy resolution, high attenuation coefficient - are potentially attractive to improve the γ-camera performances. But their use as γ detectors for medical imaging at high resolution requires production of high-grade materials and large quantities of sophisticated read-out electronics. The decision was taken to use CdTe rather than CdZnTe, because the manufacturer (Eurorad, France) has a large experience for producing high-grade materials, with a good homogeneity and stability and whose transport properties, characterised by the mobility-lifetime product, are at least 5 times greater than that of CdZnTe. The detector matrix is divided in 9 square units, each unit is composed of 256 detectors shared in 16 modules. Each module consists in a thin ceramic plate holding a line of 16 detectors, in four groups of four for an easy replacement, and holding a special 16 channels integrated circuit designed by CLRC (UK). A detection and acquisition logic based on a DSP card and a PC has been programmed by Eurorad for spectral and counting acquisition modes. Collimators LEAP and LEHR from commercial design, mobile gantry and clinical software were provided by Siemens (Germany). The γ-camera head housing, its general mounting and the electric connections were performed by Phase Laboratory (CNRS, France). The compactness of the γ-camera head, thin detectors matrix, electronic readout and collimator, facilitates the detection of close γ sources with the advantage of a high spatial resolution. Such an equipment is intended to bedside explorations. There is a growing clinical requirement in nuclear cardiology to early assess the extent of an

  2. Caractérisation temporelle et spectrale de la photoluminescence de boîtes quantiques de CdZnTe

    Science.gov (United States)

    Brimont, C.; Cronenberger, S.; Crégut, O.; Gallart, M.; Hönerlage, B.; Gilliot, P.

    2006-10-01

    Nous étudions la relaxation des paires électron-trou dans des échantillons de boîtes quantiques auto-assemblées de CdZnTe riches en cadmium incluses dans un puits quantique riche en zinc. Dans ce type de système, le couplage électron-phonon LO est le principal mécanisme responsable de la relaxation d'énergie des porteurs. Nous mesurons cette relaxation par photoluminescence résolue en temps, en fonction de l'intensité et de l'énergie de photon de l'excitation.

  3. Semiconductor Detectors; Detectores de Semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, E.

    2007-07-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  4. Proton irradiation results for long-wave HgCdTe infrared detector arrays for NEOCam

    CERN Document Server

    Dorn, M; McMurtry, C; Hartman, S; Mainzer, A; McKelvey, M; McMurray, R; Chevara, D; Rosser, J

    2016-01-01

    HgCdTe detector arrays with a cutoff wavelength of ~10 ${\\mu}$m intended for the NEOCam space mission were subjected to proton beam irradiation at the University of California Davis Crocker Nuclear Laboratory. Three arrays were tested - one with 800 $\\mu$m substrate intact, one with 30 $\\mu$m substrate, and one completely substrate-removed. The CdZnTe substrate, on which the HgCdTe detector is grown, has been shown to produce luminescence in shorter wave HgCdTe arrays that causes elevated signal in non-hit pixels when subjected to proton irradiation. This testing was conducted to ascertain whether or not full substrate removal is necessary. At the dark level of the dewar, we detect no luminescence in non-hit pixels during proton testing for both the substrate-removed detector array and the array with 30 ${\\mu}$m substrate. The detector array with full 800 ${\\mu}$m substrate exhibited substantial photocurrent for a flux of 103 protons/cm$^2$-s at a beam energy of 18.1 MeV (~ 750 e$^-$/s) and 34.4 MeV ($\\sim$ 6...

  5. Correlated analysis of 2 MeV proton-induced radiation damage in CdZnTe crystals using photoluminescence and thermally stimulated current techniques

    Science.gov (United States)

    Gu, Yaxu; Jie, Wanqi; Rong, Caicai; Wang, Yuhan; Xu, Lingyan; Xu, Yadong; Lv, Haoyan; Shen, Hao; Du, Guanghua; Fu, Xu; Guo, Na; Zha, Gangqiang; Wang, Tao

    2016-11-01

    Radiation damage induced by 2 MeV protons in CdZnTe crystals has been studied by means of photoluminescence (PL) and thermally stimulated current (TSC) techniques. A notable quenching of PL intensity is observed in the regions irradiated with a fluence of 6 × 1013 p/cm2, suggesting the increase of non-radiative recombination centers. Moreover, the intensity of emission peak Dcomplex centered at 1.48 eV dominates in the PL spectrum obtained from irradiated regions, ascribed to the increase of interstitial dislocation loops and A centers. The intensity of TSC spectra in irradiated regions decreases compared to the virgin regions, resulting from the charge collection inefficiency caused by proton-induced recombination centers. By comparing the intensity of identified traps obtained from numerical fitting using simultaneous multiple peak analysis (SIMPA) method, it suggests that proton irradiation under such dose can introduce high density of dislocation and A-centers in CdZnTe crystals, consistent with PL results.

  6. Thermal conductivity studies of CdZnTe with varying Te excess

    Science.gov (United States)

    Jackson, Maxx; Bennett, Brittany; Giltnane, Dustin; Babalola, Stephen; Ohmes, Martin F.; Stowe, A. C.

    2016-09-01

    Cadmium Zine Telluride (CZT) has been extensively studied as a room temperature semiconductor gamma radiation detector. CZT continues to show promise as a bulk and pixelated gamma spectrometer with less than one percent energy resolution; however the fabrication costs are high. Improved yields of high quality, large CZT spectroscopy grade crystals must be achieved. CZT is grown by the Traveling Heater Method (THM) with a Te overpressure to account for vaporization losses. This procedure creates Te rich zones. During growth, boules will often cleave limiting the number of harvestable crystals. As a result, crystal growth parameter optimization was evaluated by modeling the heat flow within the system. Interestingly, Cadmium Telluride (CdTe) is used as a thermal conductivity surrogate in the absence of a thorough study of the CZT thermal properties. The current study has measured the thermal conductivity of CZT pressed powders with varying Te concentrations from 50-100% over 25-800°C to understand the variation in this parameter from CdTe. Cd0.9Zn0.1Te1.0 is the base CZT (designated 50%). CZT exhibits a thermal conductivity of nearly 1 W/mK, an order of magnitude greater than CdTe. Further, the thermal conductivity decreased with increasing Te concentration.

  7. Monte Carlo based performance assessment of different animal PET architectures using pixellated CZT detectors

    Energy Technology Data Exchange (ETDEWEB)

    Visvikis, D. [INSERM U650, LaTIM, University Hospital Medical School, F-29609 Brest (France)]. E-mail: Visvikis.Dimitris@univ-brest.fr; Lefevre, T. [INSERM U650, LaTIM, University Hospital Medical School, F-29609 Brest (France); Lamare, F. [INSERM U650, LaTIM, University Hospital Medical School, F-29609 Brest (France); Kontaxakis, G. [ETSI Telecomunicacion Universidad Politecnica de Madrid, Ciudad Universitaria, s/n 28040, Madrid (Spain); Santos, A. [ETSI Telecomunicacion Universidad Politecnica de Madrid, Ciudad Universitaria, s/n 28040, Madrid (Spain); Darambara, D. [Department of Physics, School of Engineering and Physical Sciences, University of Surrey, Guildford (United Kingdom)

    2006-12-20

    The majority of present position emission tomography (PET) animal systems are based on the coupling of high-density scintillators and light detectors. A disadvantage of these detector configurations is the compromise between image resolution, sensitivity and energy resolution. In addition, current combined imaging devices are based on simply placing back-to-back and in axial alignment different apparatus without any significant level of software or hardware integration. The use of semiconductor CdZnTe (CZT) detectors is a promising alternative to scintillators for gamma-ray imaging systems. At the same time CZT detectors have the potential properties necessary for the construction of a truly integrated imaging device (PET/SPECT/CT). The aims of this study was to assess the performance of different small animal PET scanner architectures based on CZT pixellated detectors and compare their performance with that of state of the art existing PET animal scanners. Different scanner architectures were modelled using GATE (Geant4 Application for Tomographic Emission). Particular scanner design characteristics included an overall cylindrical scanner format of 8 and 24 cm in axial and transaxial field of view, respectively, and a temporal coincidence window of 8 ns. Different individual detector modules were investigated, considering pixel pitch down to 0.625 mm and detector thickness from 1 to 5 mm. Modified NEMA NU2-2001 protocols were used in order to simulate performance based on mouse, rat and monkey imaging conditions. These protocols allowed us to directly compare the performance of the proposed geometries with the latest generation of current small animal systems. Results attained demonstrate the potential for higher NECR with CZT based scanners in comparison to scintillator based animal systems.

  8. Semiconductor Detector Developments for High Energy Space Astronomy

    CERN Document Server

    Meuris, Aline

    2014-01-01

    The rise of high energy astrophysics and solar physics in the 20th century is linked to the development of space telescopes; since the 1960s they have given access to the X-ray and gamma-ray sky, revealing the most violent phenomena in the Universe. Research and developments in imaging concepts and sensing materials haven't stopped since yet to improve the sensitivity of the X-ray and gamma-ray observatories. The paper proposes an overview of instrument realizations and focuses on the innovative detection techniques and technologies for applications from 0.1 keV to 10 MeV energy range. Solid-state detectors are prominent solutions for space instrumentation because of their excellent imaging and spectroscopic capabilities with limited volume and power resources. Various detection concepts based on semiconductors (Compton camera, Cd(Zn)Te pixel hybrids, DePFET active pixel sensors) are under design or fabrication for the near-future missions like Astro-H, BepiColombo, Solar Orbiter. New technologies on sensing ...

  9. Radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Taleyarkhan, Rusi P.

    2017-06-27

    Alpha particle detecting devices are disclosed that have a chamber that can hold a fluid in a tensioned metastable state. The chamber is tuned with a suitable fluid and tension such that alpha emitting materials such as radon and one or more of its decay products can be detected. The devices can be portable and can be placed in areas, such as rooms in dwellings or laboratories and used to measure radon in these areas, in situ and in real time. The disclosed detectors can detect radon at and below 4 pCi/L in air; also, at and below 4,000 pCi/L or 300 pCi/L in water.

  10. Material properties limiting the performance of CZT gamma-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov,A.E.; Babalola, S.; Camarda, G. S.; Cui, Y.; Egarievwe, S. U.; Hossain, A.; Yang, G.; James, R. B.

    2009-03-16

    CdZnTe (CZT) nuclear radiation detectors are advanced sensors that utilize innovative technologies developed for wide band-gap semiconductor industry and microelectronics. They open opportunities for new types of room-temperature operating, field deployable instruments that provide accurate identification of potential radiological threats and timely awareness for both the civilian and military communities. Room-temperature radiation detectors are an emerging technology that relies on the use of high-quality CZT crystals whose availability is currently limited by material non-uniformities and the presence of extended defects. To address these issues, which are most critical to CZT sensor developments, we developed X-ray mapping and IR transmission microscopy systems to characterize both CZT crystals and devices. Since a customized system is required for such X-ray measurements, we use synchrotron radiation beams available at BNL's National Synchrotron Light Source. A highly-collimated and high-intensity X-ray beam supports measurements of areas as small as 10 x 10 {micro}m{sup 2}, and allowed us to see fluctuations in collected charge over the entire area of the detector in a reasonable time. The IR microscopy system allows for 3D visualization of Te inclusions and other extended defects. In this paper, we describe the experimental techniques used in our measurements and typical results obtained from CZT samples produced by different suppliers.

  11. Characterization of the imaging performance of the simultaneously counting and integrating X-ray detector CIX

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Johannes

    2010-01-15

    The CIX detector is a direct converting hybrid pixel detector designed for medical X-ray imaging applications. Its de ning feature is the simultaneous operation of a photon counter as well as an integrator in every pixel cell. This novel approach o ers a dynamic range of more than five orders of magnitude, as well as the ability to directly obtain the average photon energy from the measured data. Several CIX 0.2 ASICs have been successfully connected to CdTe, CdZnTe and Si sensors. These detector modules were tested with respect to the imaging performance of the simultaneously counting and integrating concept under X-ray irradiation. Apart from a characterization of the intrinsic benefits of the CIX concept, the sensor performance was also investigated. Here, the two parallel signal processing concepts offer valuable insights into material related effects like polarization and temporal response. The impact of interpixel coupling effects like charge-sharing, Compton scattering and X-ray fluorescence was evaluated through simulations and measurements. (orig.)

  12. Development of a low-noise, 4th-order readout ASIC for CdZnTe detectors in gamma spectrometer applications

    Science.gov (United States)

    Wang, Jia; Su, Lin; Wei, Xiaomin; Zheng, Ran; Hu, Yann

    2016-09-01

    This paper presents an ASIC readout circuit development, which aims to achieve low noise. In order to compensate the leakage current and improve gain, a dual-stage CSA has been utilized. A 4th-order high-linearity shaper is proposed to obtain a Semi-Gaussian wave and further decrease the noise induced by the leakage current. The ASIC has been designed and fabricated in a standard commercial 2P4M 0.35 μm CMOS process. Die area of one channel is about 1190 μm×147 μm. The input charge range is 1.8 fC. The peaking time can be adjusted from 1 μs to 3 μs. Measured ENC is about 55e- (rms) at input capacitor of 0 F. The gain is 271 mV/fC at the peaking time of 1 μs.

  13. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  14. Pixel Vertex Detectors

    OpenAIRE

    Wermes, Norbert

    2006-01-01

    Pixel vertex detectors are THE instrument of choice for the tracking of charged particles close to the interaction point at the LHC. Hybrid pixel detectors, in which sensor and read-out IC are separate entities, constitute the present state of the art in detector technology. Three of the LHC detectors use vertex detectors based on this technology. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as ...

  15. Multi-energy x-ray detectors to improve air-cargo security

    Science.gov (United States)

    Paulus, Caroline; Moulin, Vincent; Perion, Didier; Radisson, Patrick; Verger, Loïck

    2017-05-01

    X-ray based systems have been used for decades to screen luggage or cargo to detect illicit material. The advent of energy-sensitive photon-counting x-ray detectors mainly based on Cd(Zn)Te semi-conductor technology enables to improve discrimination between materials compared to single or dual energy technology. The presented work is part of the EUROSKY European project to develop a Single European Secure Air-Cargo Space. "Cargo" context implies the presence of relatively heavy objects and with potentially high atomic number. All the study is conducted on simulations with three different detectors: a typical dual energy sandwich detector, a realistic model of the commercial ME100 multi-energy detector marketed by MULTIX, and a ME100 "Cargo": a not yet existing modified multi-energy version of the ME100 more suited to air freight cargo inspection. Firstly, a comparison on simulated measurements shows the performances improvement of the new multi-energy detectors compared to the current dual-energy one. The relative performances are evaluated according to different criteria of separability or contrast-to-noise ratio and the impact of different parameters is studied (influence of channel number, type of materials and tube voltage). Secondly, performances of multi-energy detectors for overlaps processing in a dual-view system is accessed: the case of orthogonal projections has been studied, one giving dimensional values, the other one providing spectral data to assess effective atomic number. A method of overlap correction has been proposed and extended to multi-layer objects case. Therefore, Calibration and processing based on bi-material decomposition have been adapted for this purpose.

  16. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  17. Proton irradiation results for long-wave HgCdTe infrared detector arrays for Near-Earth Object Camera

    Science.gov (United States)

    Dorn, Meghan L.; Pipher, Judith L.; McMurtry, Craig; Hartman, Spencer; Mainzer, Amy; McKelvey, Mark; McMurray, Robert; Chevara, David; Rosser, Joshua

    2016-07-01

    HgCdTe detector arrays with a cutoff wavelength of ˜10 μm intended for the Near-Earth Object Camera (NEOCam) space mission were subjected to proton-beam irradiation at the University of California Davis Crocker Nuclear Laboratory. Three arrays were tested-one with 800-μm substrate intact, one with 30-μm substrate, and one completely substrate-removed. The CdZnTe substrate, on which the HgCdTe detector is grown, has been shown to produce luminescence in shorter wave HgCdTe arrays that causes an elevated signal in nonhit pixels when subjected to proton irradiation. This testing was conducted to ascertain whether or not full substrate removal is necessary. At the dark level of the dewar, we detect no luminescence in nonhit pixels during proton testing for both the substrate-removed detector array and the array with 30-μm substrate. The detector array with full 800-μm substrate exhibited substantial photocurrent for a flux of 103 protons/cm2 s at a beam energy of 18.1 MeV (˜750 e-/s) and 34.4 MeV (˜65 e-/s). For the integrated space-like ambient proton flux level measured by the Spitzer Space Telescope, the luminescence would be well below the NEOCam dark current requirement of <200 e-/s, but the pattern of luminescence could be problematic, possibly complicating calibration.

  18. Imaging, Detection, and Identification Algorithms for Position-Sensitive Gamma-Ray Detectors

    Science.gov (United States)

    Wahl, Christopher G.

    Three-dimensional-position-sensitive semiconductors record both the locations and energies of gamma-ray interactions with high resolution, enabling spectroscopy and imaging of gamma-ray-emitting materials. Imaging enables the detection of point sources of gamma rays in an otherwise extended-source background, even when the background spectrum is unknown and may share the point source's spectrum. The generalized likelihood ratio test (GLRT) and source-intensity test (SIT) are applied to this situation to detect one-or-more unshielded point sources from a library of isotopes in a spectrally unknown or known background when the background intensity varies spatially by a factor of two or less. In addition to estimating the number of sources present, their activities, isotopes, and directions from the detector are estimated. Experimental and some simulated results are presented for a single detector and an 18-detector array of 2 cm by 2 cm by 1.5 cm CdZnTe crystals and compared with the performance of spectral-only detection when the background and source are assumed to be spectrally different. Furthermore, the expected detection performance of the 18-detector array system is investigated statistically using experimental data in the case where the background is distinct spectrally from the point source and the possible source location and isotopic identity are known. Including imaging gave at least 7% higher SNR compared to ignoring the image dimension. Also, imaging methods based on the maximum-likelihood, expectation-maximization method are introduced to determine the spatial distribution of isotopes and to find the activity distributions within targets moving with known motion through a radioactive background. Software has also been developed to support the analysis of the data from 3D-position-sensitive spectroscopic systems, for a range of detector designs and applications. The software design and unique features that allow fast multidimensional data analysis are

  19. CIX - A Detector for Spectral Enhanced X-ray Imaging by Simultaneous Counting and Integrating

    CERN Document Server

    Krüger, H; Kraft, E; Wermes, N; Fischer, P; Peric, I; Herrmann, C; Overdick, M; Rütten, W

    2008-01-01

    A hybrid pixel detector based on the concept of simultaneous charge integration and photon counting will be presented. The second generation of a counting and integrating X-ray prototype CMOS chip (CIX) has been operated with different direct converting sensor materials (CdZnTe and CdTe) bump bonded to its 8x8 pixel matrix. Photon counting devices give excellent results for low to medium X-ray fluxes but saturate at high rates while charge integration allows the detection of very high fluxes but is limited at low rates by the finite signal to noise ratio. The combination of both signal processing concepts therefore extends the resolvable dynamic range of the X-ray detector. In addition, for a large region of the dynamic range, where counter and integrator operate simultaneously, the mean energy of the detected X-ray spectrum can be calculated. This spectral information can be used to enhance the contrast of the X-ray image. The advantages of the counting and integrating signal processing concept and the perfo...

  20. The MINOS Detectors

    CERN Document Server

    Grashorn, A H E W

    2005-01-01

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

  1. GADRAS Detector Response Function.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

    2014-11-01

    The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

  2. The TALE Tower Detector

    Science.gov (United States)

    Bergman, D. R.

    The TA Low Energy Extension will include a Tower FluorescenceDetector. Extensive air showers at the lowest usful energies for fluorescence detectors will in general be close to the detector. This requires viewing all elevation angles to be able to reconstruct showers. The TALE Tower Detector, operating in conjunction with other TALE detectors will view elevation angles up to above 70 degrees, with an azimuthal coverage of about 90 degrees. Results from a prototype mirror operated in conjunction with the HiRes detector will also be presented.

  3. Drift Chambers detectors; Detectores de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I.; Martinez laso, L.

    1989-07-01

    We present here a review of High Energy Physics detectors based on drift chambers. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysed, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author) 115 refs.

  4. Development of Tiled Imaging CZT Detectors for Sensitive Wide-Field Hard X-Ray Surveys to EXIST

    Science.gov (United States)

    Grindlay, J.; Hong, J.; Allen, B.; Barthelmy, S.; Baker, R.

    2011-01-01

    Motivated by the proposed EXIST mission, a "medium-class" space observatory to survey black holes and the Early Universe proposed to the 2010 NAS/NRC Astronomy and Astrophysics Decadal Survey, we have developed the first "large" area 256 sq cm close-tiled (0.6 mm gaps) hard X-ray (20-600 keV) imaging detector employing pixelated (2.5 mm) CdZnTe (CZT) detectors, each 2 x 2 x 0.5 cubic cm. We summarize the design, development and operation of this detector array (8 x 8 CZTs) and its performance as the imager for a coded aperture telescope on a high altitude (40 km) balloon flight in October. 2009, as the ProtoEX1STl payload. We then outline our current development of a second-generation imager, ProtcEXIST2. with 0.6 mm pixels on a 32 x 32 array on each CZT, and how it will lead to the ultimate imaging system needed for EXIST. Other applications of this technology will also be mentioned.

  5. Grating-based interferometry and hybrid photon counting detectors: Towards a new era in X-ray medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gkoumas, Spyridon, E-mail: spyridon.gkoumas@psi.ch [Swiss Light Source, Paul Scherrer Institut, Villigen 5232 (Switzerland); Wang, Zhentian; Abis, Matteo; Arboleda, Carolina [Swiss Light Source, Paul Scherrer Institut, Villigen 5232 (Switzerland); Institute for Biomedical Engineering,University and ETH Zurich, Zurich 8092 (Switzerland); Tudosie, George; Donath, Tilman; Brönnimann, Christian; Schulze-Briese, Clemens [Dectris Ltd., Neuenhoferstrasse 107, Baden 5400 (Switzerland); Stampanoni, Marco [Swiss Light Source, Paul Scherrer Institut, Villigen 5232 (Switzerland); Institute for Biomedical Engineering,University and ETH Zurich, Zurich 8092 (Switzerland)

    2016-02-11

    Progress in X-ray medical imaging and advances in detector developments have always been closely related. Similarly, a strong connection exists between innovations in synchrotron imaging and their implementation on table-top X-ray tube setups. The transfer of phase-based imaging to X-ray tubes can provide table-top setups with improved contrast between areas of low attenuation differences, by exploiting the unit decrement of the real part of the refractive index. Medical imaging is a potential application for such a system. Originally developed for synchrotron experiments, the novel generation of hybrid photon counting detectors is becoming increasingly popular due to their unique characteristics, such as small pixel size, negligible dark noise, fast counting and adjustable energy thresholds. Furthermore, novel room temperature semiconductor materials such as Cd(Zn)Te can provide higher quantum efficiency. In the first part of this article we review phase-contrast techniques and recent research towards medical applications. In the second part we present results and evaluate the potential of combining a table-top Talbot grating interferometry system with latest generation hybrid photon counting detectors.

  6. Thermal kinetic inductance detector

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, Thomas; Gades, Lisa; Miceli, Antonio; Quaranta, Orlando

    2016-12-20

    A microcalorimeter for radiation detection that uses superconducting kinetic inductance resonators as the thermometers. The detector is frequency-multiplexed which enables detector systems with a large number of pixels.

  7. Forward tracking detectors

    Indian Academy of Sciences (India)

    Klaus Mönig

    2007-11-01

    Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  8. The OSMOND detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Dalgliesh, R. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Duxbury, D.M., E-mail: dom.duxbury@stfc.ac.uk [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Holt, S.A.; Kinane, C.J. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Marsh, A.S. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Rhodes, N.J.; Schooneveld, E.M. [ISIS Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom); Spill, E.J.; Stephenson, R. [Technology Dept. Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Oxfordshire, OX11 0QX (United Kingdom)

    2013-01-11

    The development and testing of the Off Specular MicrOstrip Neutron Detector (OSMOND) is described. Based on a microstrip gas chamber the aim of the project was to produce a high counting rate detector capable of replacing the existing rate limited scintillator detectors currently in use on the CRISP reflectometer for off specular reflectometry experiments. The detector system is described together with results of neutron beam tests carried out at the ISIS spallation neutron source.

  9. The CAPRICE RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Basini, G. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Codino, A.; Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata` Rome (Italy); Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Brancaccio, F.; Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy)

    1995-09-01

    A compact RICH detector has been developed and used for particle identification in a balloon borne spectrometer to measure the flux of antimatter in the cosmic radiation. This is the first RICH detector ever used in space experiments that is capable of detecting unit charged particles, such as antiprotons. The RICH and all other detectors performed well during the 27 hours long flight.

  10. Optimization of K-edge imaging for vulnerable plaques using gold nanoparticles and energy resolved photon counting detectors: a simulation study.

    Science.gov (United States)

    Alivov, Yahya; Baturin, Pavlo; Le, Huy Q; Ducote, Justin; Molloi, Sabee

    2014-01-06

    We investigated the effect of different imaging parameters, such as dose, beam energy, energy resolution and the number of energy bins, on the image quality of K-edge spectral computed tomography (CT) of gold nanoparticles (GNP) accumulated in an atherosclerotic plaque. A maximum likelihood technique was employed to estimate the concentration of GNP, which served as a targeted intravenous contrast material intended to detect the degree of the plaque's inflammation. The simulation studies used a single-slice parallel beam CT geometry with an x-ray beam energy ranging between 50 and 140 kVp. The synthetic phantoms included small (3 cm in diameter) cylinder and chest (33 × 24 cm(2)) phantoms, where both phantoms contained tissue, calcium and gold. In the simulation studies, GNP quantification and background (calcium and tissue) suppression tasks were pursued. The x-ray detection sensor was represented by an energy resolved photon counting detector (e.g., CdZnTe) with adjustable energy bins. Both ideal and more realistic (12% full width at half maximum (FWHM) energy resolution) implementations of the photon counting detector were simulated. The simulations were performed for the CdZnTe detector with a pixel pitch of 0.5-1 mm, which corresponds to a performance without significant charge sharing and cross-talk effects. The Rose model was employed to estimate the minimum detectable concentration of GNPs. A figure of merit (FOM) was used to optimize the x-ray beam energy (kVp) to achieve the highest signal-to-noise ratio with respect to the patient dose. As a result, the successful identification of gold and background suppression was demonstrated. The highest FOM was observed at the 125 kVp x-ray beam energy. The minimum detectable GNP concentration was determined to be approximately 1.06 µmol mL(-1) (0.21 mg mL(-1)) for an ideal detector and about 2.5 µmol mL(-1) (0.49 mg mL(-1)) for a more realistic (12% FWHM) detector. The studies show the optimal

  11. Flight Performance of an advanced CZT Imaging Detector in a Balloon-borne Wide-Field Hard X-ray Telescope - ProtoEXIST1

    CERN Document Server

    Hong, J; Grindlay, J; Barthelemy, S; Baker, R; Garson, A; Krawczynski, H; Apple, J; Cleveland, W H

    2011-01-01

    We successfully carried out the first high-altitude balloon flight of a wide-field hard X-ray coded-aperture telescope ProtoEXIST1, which was launched from the Columbia Scientific Balloon Facility at Ft. Sumner, New Mexico on October 9, 2009. ProtoEXIST1 is the first implementation of an advanced CdZnTe (CZT) imaging detector in our ongoing program to establish the technology required for next generation wide-field hard X-ray telescopes. The CZT detector plane in ProtoEXIST1 consists of an 8 x 8 array of closely tiled 2 cm x 2 cm x 0.5 cm thick pixellated CZT crystals, each with 8 x 8 pixels, covering a 256 cm^2 active area with 2.5 mm pixels. A tungsten mask, mounted at 90 cm above the detector provides shadowgrams of X-ray sources in the 30 - 600 keV band for imaging, allowing a fully coded field of view of 9 Deg x 9 Deg with an angular resolution of 20 arcmin. To reduce the background radiation, the detector is surrounded by semi-graded (Pb/Sn/Cu) passive shields on the four sides all the way to the mask. ...

  12. Equalized near maximum likelihood detector

    OpenAIRE

    2012-01-01

    This paper presents new detector that is used to mitigate intersymbol interference introduced by bandlimited channels. This detector is named equalized near maximum likelihood detector which combines nonlinear equalizer and near maximum likelihood detector. Simulation results show that the performance of equalized near maximum likelihood detector is better than the performance of nonlinear equalizer but worse than near maximum likelihood detector.

  13. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  14. Nondestructive Characterization of Residual Threading Dislocation Density in HgCdTe Layers Grown on CdZnTe by Liquid-Phase Epitaxy

    Science.gov (United States)

    Fourreau, Y.; Pantzas, K.; Patriarche, G.; Destefanis, V.

    2016-09-01

    The performance of mercury cadmium telluride (MCT)-based infrared (IR) focal-plane arrays is closely related to the crystalline perfection of the HgCdTe thin film. In this work, Te-rich, (111)B-oriented HgCdTe epilayers grown by liquid-phase epitaxy on CdZnTe substrates have been studied. Surface atomic steps are shown on as-grown MCT materials using atomic force microscopy (AFM) and white-light interferometry (WLI), suggesting step-flow growth. Locally, quasiperfect surface spirals are also evidenced. A demonstration is given that these spirals are related to the emergence of almost pure screw threading dislocations. A nondestructive and quantitative technique to measure the threading dislocation density is proposed. The technique consists of counting the surface spirals on the as-grown MCT surface from images obtained by either AFM or WLI measurements. The benefits and drawbacks of both destructive—chemical etching of HgCdTe dislocations—and nondestructive surface imaging techniques are compared. The nature of defects is also discussed. Finally, state-of-the-art threading dislocation densities in the low 104 cm-2 range are evidenced by both etch pit density (EPD) and surface imaging measurements.

  15. Imaging X-ray detector front-end with high dynamic range: IDeF-X HD

    Energy Technology Data Exchange (ETDEWEB)

    Gevin, O.; Lemaire, O.; Lugiez, F. [CEA, Irfu, Service d' Electronique, de Detecteurs et d' Informatique, Bat. 141, F-91191 Gif-sur-Yvette (France); Michalowska, A., E-mail: alicja.michalowska@cea.fr [CEA, Irfu, Service d' Electronique, de Detecteurs et d' Informatique, Bat. 141, F-91191 Gif-sur-Yvette (France); Baron, P. [CEA, Irfu, Service d' Electronique, de Detecteurs et d' Informatique, Bat. 141, F-91191 Gif-sur-Yvette (France); Limousin, O. [CEA, Irfu, Service d' Astrophysique, Bat. 709 Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Delagnes, E. [CEA, Irfu, Service d' Electronique, de Detecteurs et d' Informatique, Bat. 141, F-91191 Gif-sur-Yvette (France)

    2012-12-11

    Presented circuit, IDeF-X HD (Imaging Detector Front-end) is a member of the IDeF-X ASICs family for space applications. It has been optimized for a half millimeter pitch CdTe or CdZnTe pixelated detector arranged in 16 Multiplication-Sign 16 array. It is aimed to operate in the hard X-ray range from few keV up to 250 keV or more. The ASIC has been realized in AMS 0.35 {mu}m CMOS process. The IDeF-X HD is a 32 channel analog front-end with self-triggering capability. The architecture of the analog channel includes a chain of charge sensitive amplifier with continuous reset system and non-stationary noise suppressor, adjustable gain stage, pole-zero cancellation stage, adjustable shaping time low pass filter, baseline holder and peak detector with discriminator. The power consumption of the IDeF-X HD is 800 {mu}W per channel. With the in-channel variable gain stage the nominal 250 keV dynamic range of the ASIC can be extended up to 1 MeV anticipating future applications using thick sensors. Measuring the noise performance without a detector at the input with minimized leakage current (programmable) at the input, we achieved ENC of 33 electrons rms at 10.7 {mu}s peak time. Measurements with CdTe detector show good energy resolution FWHM of 1.1 keV at 60 keV and 4.3 keV at 662 keV with detection threshold below 4 keV. In addition, an absolute temperature sensor has been integrated with resolution of 1.5 Degree-Sign C.

  16. Imaging X-ray detector front-end with high dynamic range: IDeF-X HD

    Science.gov (United States)

    Gevin, O.; Lemaire, O.; Lugiez, F.; Michalowska, A.; Baron, P.; Limousin, O.; Delagnes, E.

    2012-12-01

    Presented circuit, IDeF-X HD (Imaging Detector Front-end) is a member of the IDeF-X ASICs family for space applications. It has been optimized for a half millimeter pitch CdTe or CdZnTe pixelated detector arranged in 16×16 array. It is aimed to operate in the hard X-ray range from few keV up to 250 keV or more. The ASIC has been realized in AMS 0.35 μm CMOS process. The IDeF-X HD is a 32 channel analog front-end with self-triggering capability. The architecture of the analog channel includes a chain of charge sensitive amplifier with continuous reset system and non-stationary noise suppressor, adjustable gain stage, pole-zero cancellation stage, adjustable shaping time low pass filter, baseline holder and peak detector with discriminator. The power consumption of the IDeF-X HD is 800 μW per channel. With the in-channel variable gain stage the nominal 250 keV dynamic range of the ASIC can be extended up to 1 MeV anticipating future applications using thick sensors. Measuring the noise performance without a detector at the input with minimized leakage current (programmable) at the input, we achieved ENC of 33 electrons rms at 10.7 μs peak time. Measurements with CdTe detector show good energy resolution FWHM of 1.1 keV at 60 keV and 4.3 keV at 662 keV with detection threshold below 4 keV. In addition, an absolute temperature sensor has been integrated with resolution of 1.5 °C.

  17. The DØ detector

    Science.gov (United States)

    Abachi, S.; Abolins, M.; Acharya, B. S.; Adam, I.; Ahn, S.; Aihara, H.; Alvarez, G.; Alves, G. A.; Amos, N.; Anderson, W.; Antipov, Yu.; Aronson, S. H.; Astur, R.; Avery, R. E.; Baden, A.; Balderston, J.; Baldin, B.; Bantly, J.; Barasch, E.; Bartlett, J. F.; Bazizi, K.; Behnke, T.; Bezzubov, V.; Bhat, P. C.; Blazey, G.; Blessing, S.; Boehnlein, A.; Borcherding, F.; Borders, J.; Bozko, N.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoy, V.; Butler, J. M.; Callot, O.; Chakraborty, D.; Chekulaev, S.; Chen, J.; Chen, L.-P.; Chen, W.; Choudhary, B. C.; Christenson, J. H.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M.; Cutts, D.; Dahl, O. I.; Daniels, B.; De, K.; Demarteau, M.; Denisenko, K.; Denisenko, N.; Denisov, D.; Denisov, S.; Dharmaratna, W.; Diehl, H. T.; Diesburg, M.; Dixon, R.; Draper, P.; Ducros, Y.; Durston-Johnson, S.; Eartly, D.; Eberhard, P. H.; Edmunds, D.; Efimov, A.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eroshin, O.; Evdokimov, V.; Fahey, S.; Fanourakis, G.; Fatyga, M.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finley, D.; Finocchiaro, G.; Fisk, H. E.; Flattum, E.; Forden, G. E.; Fortner, M.; Franzini, P.; Fuess, S.; Gallas, E.; Gao, C. S.; Geld, T. L.; Genser, K.; Gerber, C. E.; Gibbard, B.; Glebov, V.; Glicenstein, J. F.; Gobbi, B.; Goforth, M.; Good, M. L.; Goozen, F.; Gordon, H.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Grossman, N.; Grudberg, P.; Guida, J. A.; Guida, J. M.; Guryn, W.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hansen, S.; Hauptman, J.; Hedin, D.; Heinson, A. P.; Heintz, U.; Heuring, T.; Hirosky, R.; Hodel, K.; Hoftun, J. S.; Hubbard, J. R.; Huehn, T.; Huson, R.; Igarashi, S.; Ito, A. S.; James, E.; Jiang, J.; Johns, K.; Johnson, C. R.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jung, C. K.; Kahn, S.; Kanekal, S.; Kernan, A.; Kerth, L.; Kirunin, A.; Klatchko, A.; Klima, B.; Klochkov, B.; Klopfenstein, C.; Klyukhin, V.; Kochetkov, V.; Kohli, J. M.; Kononenko, W.; Kotcher, J.; Kotov, I.; Kourlas, J.; Kozelov, A.; Kozlovsky, E.; Krafczyk, G.; Krempetz, K.; Krishnaswamy, M. R.; Kroon, P.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Landsberg, G.; Lanou, R. E.; Laurens, P.; Lee-Franzini, J.; Li, J.; Li, R.; Li-Demarteau, Q. Z.; Lima, J. G. R.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y.-C.; Lloyd-Owen, D.; Lobkowicz, F.; Loken, S. C.; Lokos, S.; Lueking, L.; Maciel, A. K. A.; Madaras, R. J.; Madden, R.; Malamud, E.; Mangeot, Ph.; Manning, I.; Mansoulié, B.; Manzella, V.; Mao, H.-S.; Marcin, M.; Markosky, L.; Marshall, T.; Martin, H. J.; Martin, M. I.; Martin, P. S.; Marx, M.; May, B.; Mayorov, A.; McCarthy, R.; McKinley, J.; Mendoza, D.; Meng, X.-C.; Merritt, K. W.; Milder, A.; Mincer, A.; Mondal, N. K.; Montag, M.; Mooney, P.; Mudan, M.; Mulholland, G. T.; Murphy, C.; Murphy, C. T.; Nang, F.; Narain, M.; Narasimham, V. S.; Neal, H. A.; Nemethy, P.; Nešić, D.; Ng, K. K.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Pang, M.; Para, A.; Park, C. H.; Partridge, R.; Paterno, M.; Peryshkin, A.; Peters, M.; Pi, B.; Piekarz, H.; Pischalnikov, Yu.; Pizzuto, D.; Pluquet, A.; Podstavkov, V.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Que, Y.-K.; Quintas, P. Z.; Rahal-Callot, G.; Raja, R.; Rajagopalan, S.; Rao, M. V. S.; Rasmussen, L.; Read, A. L.; Regan, T.; Repond, S.; Riadovikov, V.; Rijssenbeek, M.; Roe, N. A.; Rubinov, P.; Rutherfoord, J.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Sculli, J.; Selove, W.; Shea, M.; Shkurenkov, A.; Shupe, M.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, A.; Smith, D.; Smith, R. P.; Snow, G. R.; Snyder, S.; Sosebee, M.; Souza, M.; Spadafora, A. L.; Stampke, S.; Stephens, R.; Stevenson, M. L.; Stewart, D.; Stocker, F.; Stoyanova, D.; Stredde, H.; Streets, K.; Strovink, M.; Suhanov, A.; Taketani, A.; Tartaglia, M.; Taylor, J. D.; Teiger, J.; Theodosiou, G.; Thompson, J.; Tisserant, S.; Trippe, T. G.; Tuts, P. M.; Van Berg, R.; Vaz, M.; Vishwanath, P. R.; Volkov, A.; Vorobiev, A.; Wahl, H. D.; Wang, D.-C.; Wang, L.-Z.; Weerts, H.; Wenzel, W. A.; White, A.; White, J. T.; Wightman, J.; Willis, S.; Wimpenny, S. J.; Wolf, Z.; Womersley, J.; Wood, D. R.; Xia, Y.; Xiao, D.; Xie, P.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yang, M.-J.; Yoshikawa, C.; Youssef, S.; Yu, J.; Zeller, R.; Zhang, S.; Zhou, Y. H.; Zhu, Q.; Zhu, Y.-S.; Zieminska, D.; Zieminski, A.; Zinchenko, A.; Zylberstejn, A.; DØ Collaboration

    1994-01-01

    The DØ detector is a large general purpose detector for the study of short-distance phenomena in high energy antiproton-proton collisions, now in operation at the Fermilab Tevatron collider. The detector focusses upon the detection of electrons, muons, jets and missing transverse momentum. We describe the design and performance of the major elements of the detector, including the tracking chambers, transition radiation detector, liquid argon calorimetry and muon detection. The associated electronics, triggering systems and data acquisition systems are presented. The global mechanical, high voltage, and experiment monitoring and control systems which support the detector are described. We also discuss the design and implementation of software and software support systems that are specific to DØ.

  18. Radiation dose reduction using a CdZnTe-based computed tomography system: Comparison to flat-panel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Le, Huy Q.; Ducote, Justin L.; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

    2010-03-15

    Purpose: Although x-ray projection mammography has been very effective in early detection of breast cancer, its utility is reduced in the detection of small lesions that are occult or in dense breasts. One drawback is that the inherent superposition of parenchymal structures makes visualization of small lesions difficult. Breast computed tomography using flat-panel detectors has been developed to address this limitation by producing three-dimensional data while at the same time providing more comfort to the patients by eliminating breast compression. Flat panels are charge integrating detectors and therefore lack energy resolution capability. Recent advances in solid state semiconductor x-ray detector materials and associated electronics allow the investigation of x-ray imaging systems that use a photon counting and energy discriminating detector, which is the subject of this article. Methods: A small field-of-view computed tomography (CT) system that uses CdZnTe (CZT) photon counting detector was compared to one that uses a flat-panel detector for different imaging tasks in breast imaging. The benefits afforded by the CZT detector in the energy weighting modes were investigated. Two types of energy weighting methods were studied: Projection based and image based. Simulation and phantom studies were performed with a 2.5 cm polymethyl methacrylate (PMMA) cylinder filled with iodine and calcium contrast objects. Simulation was also performed on a 10 cm breast specimen. Results: The contrast-to-noise ratio improvements as compared to flat-panel detectors were 1.30 and 1.28 (projection based) and 1.35 and 1.25 (image based) for iodine over PMMA and hydroxylapatite over PMMA, respectively. Corresponding simulation values were 1.81 and 1.48 (projection based) and 1.85 and 1.48 (image based). Dose reductions using the CZT detector were 52.05% and 49.45% for iodine and hydroxyapatite imaging, respectively. Image-based weighting was also found to have the least beam

  19. Noble Gas Detectors

    CERN Document Server

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

    2006-01-01

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

  20. ATLAS inner detector performance

    CERN Document Server

    Gadomski, S

    2001-01-01

    The ATLAS Inner Detector consists of three subsystems using different tracking detector technologies: silicon pixels, silicon strips and straw tubes. The combination gives ATLAS a robust, hermetic and efficient tracking system, able to reconstruct tracks at the highest foreseen LHC luminosities. The inner detector provides vertex and momentum measurements, electron identification and some $K/\\pi$ separation. Since last year the beam pipe of ATLAS was changed, causing a redesign of the first tracking layer and a deterioration of the impact parameter resolutions.

  1. LHCb Detector Performance

    CERN Document Server

    AUTHOR|(CDS)2075808; Adeva, Bernardo; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Pessina, Gianluigi; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skillicorn, Ian; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2015-01-01

    The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are described, using data taken from 2010 to 2012. It is shown that the design criteria of the experiment have been met. The excellent performance of the detector has allowed the LHCb collaboration to publish a wide range of physics results, demonstrating LHCb's unique role, both as a heavy flavour experiment and as a general purpose detector in the forward region.

  2. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  3. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  4. Photocapacitive MIS infrared detectors

    Science.gov (United States)

    Sher, A.; Lu, S. S.-M.; Moriarty, J. A.; Crouch, R. K.; Miller, W. E.

    1978-01-01

    A new class of room-temperature infrared detectors has been developed through use of metal-insulator-semiconductor (MIS) or metal-insulator-semiconductor-insulator-metal (MISIM) slabs. The detectors, which have been fabricated from Si, Ge and GaAs, rely for operation on the electrical capacitance variations induced by modulated incident radiation. The peak detectivity for a 1000-A Si MISIM detector is comparable to that of a conventional Si detector functioning in the photovoltaic mode. Optimization of the photocapacitive-mode detection sensitivity is discussed.

  5. Multipixel characterization of imaging CZT detectors for hard x-ray imaging and spectroscopy

    Science.gov (United States)

    Vadawale, Santosh V.; Hong, Jae Sub; Grindlay, Jonathan E.; Williams, Peter; Zhang, Minhua; Bellm, Eric C.; Narita, Tomohiko; Craig, William W.; Parker, Bradford H.; Stahle, Carl M.; Yan, Feng

    2004-10-01

    We report our in-depth study of Cd-Zn-Te (CZT) crystals to determine an optimum pixel and guard band configuration for Hard X-ray imaging and spectroscopy. We tested 20x20x5mm crystals with 8x8 pixels on a 2.46mm pitch. We have studied different types of cathode / anode contacts and different pixel pad sizes. We present the measurements of leakage current as well as spectral response for each pixel. Our I-V measurement setup is custom designed to allow automated measurements of the I-V curves sequentially for all 64 pixels, whereas the radiation properties measurement setup allows for interchangeable crystals with the same XAIM3.2 ASIC readout from IDEAS. We have tested multiple crystals of each type, and each crystal in different positions to measure the variation between individual crystals and variation among the ASIC channels. We also compare the same crystals with and without a grounded guard band deposited on the crystal side walls vs. a floating guard band and compare results to simulations. This study was carried out to find the optimum CZT crystal configuration for prototype detectors for the proposed Black-Hole Finder mission, EXIST.

  6. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  7. Detector Systems at CLIC

    CERN Document Server

    Simon, Frank

    2011-01-01

    The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detector concepts for the ILC, ILD and SID, were adapted for CLIC using calorimeters with dense absorbers limiting leakage through increased compactness, as well as modified forward and vertex detector geometries and precise time stamping to cope with increased background levels. The overall detector concepts for CLIC are presented, with particular emphasis on the main detector and engineering challenges, such as: the ultra-thi...

  8. ALICE Silicon Strip Detector

    CERN Multimedia

    Nooren, G

    2013-01-01

    The Silicon Strip Detector (SSD) constitutes the two outermost layers of the Inner Tracking System (ITS) of the ALICE Experiment. The SSD plays a crucial role in the tracking of the particles produced in the collisions connecting the tracks from the external detectors (Time Projection Chamber) to the ITS. The SSD also contributes to the particle identification through the measurement of their energy loss.

  9. CMS Detector Posters

    CERN Multimedia

    2016-01-01

    CMS Detector posters (produced in 2000): CMS installation CMS collaboration From the Big Bang to Stars LHC Magnetic Field Magnet System Trackering System Tracker Electronics Calorimetry Eletromagnetic Calorimeter Hadronic Calorimeter Muon System Muon Detectors Trigger and data aquisition (DAQ) ECAL posters (produced in 2010, FR & EN): CMS ECAL CMS ECAL-Supermodule cooling and mechatronics CMS ECAL-Supermodule assembly

  10. Pixel detector readout chip

    CERN Multimedia

    1991-01-01

    Close-up of a pixel detector readout chip. The photograph shows an aera of 1 mm x 2 mm containing 12 separate readout channels. The entire chip contains 1000 readout channels (around 80 000 transistors) covering a sensitive area of 8 mm x 5 mm. The chip has been mounted on a silicon detector to detect high energy particles.

  11. The LDC detector concept

    Indian Academy of Sciences (India)

    Ties Behnke; LDC Concept Group

    2007-11-01

    In preparation of the experimental program at the international linear collider (ILC), the large detector concept (LDC) is being developed. The main points of the LDC are a large volume gaseous tracking system, combined with high precision vertex detector and an extremely granular calorimeter. The main design force behind the LDC is the particle flow concept.

  12. Introduction to detectors

    CERN Document Server

    Walenta, Albert H

    1995-01-01

    Concepts for momentum measurements,particle identification and energy measurements (calorimeters) as well for imaging applications in medecine, biology and industry (non destructive testing) will be put into relation to the specific detection princip In particular the resolution for position, time, energy and intensity measurement and the efficiency will be discussed. Signal extraction,electronic signal processing and principles of information capture will close the logic circle to the input : the radiation properties.The lecture will provide some sources for data tables and small demonstration computer programs f The basic detector physics as interaction of radiation with matter, information transport via free charges,photons and phonons and the signal formation will be presented in some depth with emphasis on the influence on specific parameters for detector The lecture will cover the most popular detector principles, gas detectors (ion chambers,MPWC's and MSGC's), semiconductor detectors scintillators and ...

  13. Nanomechanical resonance detector

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, Jeffrey C; Zettl, Alexander K

    2013-10-29

    An embodiment of a nanomechanical frequency detector includes a support structure and a plurality of elongated nanostructures coupled to the support structure. Each of the elongated nanostructures has a particular resonant frequency. The plurality of elongated nanostructures has a range of resonant frequencies. An embodiment of a method of identifying an object includes introducing the object to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the object. An embodiment of a method of identifying a molecular species of the present invention includes introducing the molecular species to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the molecular species.

  14. The PERDaix detector

    Energy Technology Data Exchange (ETDEWEB)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Kirn, Thomas, E-mail: kirn@physik.rwth-aachen.de [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany); Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhoever, Jens [I. Physikalisches Institut B, RWTH Aachen University, Aachen 52056 (Germany)

    2012-12-11

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246 Multiplication-Sign 400 Multiplication-Sign 859 mm{sup 3}, a geometrical acceptance of 32 cm{sup 2}sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  15. The PERDaix detector

    Science.gov (United States)

    Bachlechner, Andreas; Beischer, Bastian; Greim, Roman; Kirn, Thomas; Mai, Carsten; Yearwood, Gregorio Roper; Schael, Stefan; Schug, David; Tholen, Heiner; Wienkenhöver, Jens

    2012-12-01

    The PERDaix (Proton Electron Radiation Detector Aix-la-Chapelle) detector is designed to measure charged particles in cosmic rays. It can distinguish particle species up to 5 GV rigidity. PERDaix was flown on the BEXUS-11 balloon on 23rd November 2010. The detector has the dimensions of 246×400×859 mm3, a geometrical acceptance of 32 cm2sr, a low weight of 40 kg and a low power consumption of 60 W. The spectrometer consists of a time-of-flight system, a scintillating fiber tracking detector, a permanent magnet and a transition radiation detector. Silicon photomultipliers are used as photodetectors in the time-of-flight and the tracker system.

  16. ATLAS ITk Pixel detector

    CERN Document Server

    Gemme, Claudia; The ATLAS collaboration

    2016-01-01

    The high luminosity upgrade of the LHC (HL-LHC) in 2026 will provide new challenge to the ATLAS tracker. The current inner detector will be replaced with a whole silicon tracker which will consist of a five barrel layer Pixel detector surrounded by a four barrel layer Strip detector. The expected high radiation level are requiring the development of upgraded silicon sensors as well as new a front-end chip. The dense tracking environment will require finer granularity detectors. The data rates will require new technologies for high bandwidth data transmission and handling. The current status of the HL-LHC ATLA Pixel detector developments as well as the various layout options will be reviewed.

  17. SU-C-201-03: Coded Aperture Gamma-Ray Imaging Using Pixelated Semiconductor Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, S [Wayne State University, Detroit, MI (United States); Kaye, W; Jaworski, J [H3D, Inc., Ann Arbor, MI (United States); He, Z [University of Michigan, Ann Arbor, MI (United States)

    2015-06-15

    Purpose: Improved localization of gamma-ray emissions from radiotracers is essential to the progress of nuclear medicine. Polaris is a portable, room-temperature operated gamma-ray imaging spectrometer composed of two 3×3 arrays of thick CdZnTe (CZT) detectors, which detect gammas between 30keV and 3MeV with energy resolution of <1% FWHM at 662keV. Compton imaging is used to map out source distributions in 4-pi space; however, is only effective above 300keV where Compton scatter is dominant. This work extends imaging to photoelectric energies (<300keV) using coded aperture imaging (CAI), which is essential for localization of Tc-99m (140keV). Methods: CAI, similar to the pinhole camera, relies on an attenuating mask, with open/closed elements, placed between the source and position-sensitive detectors. Partial attenuation of the source results in a “shadow” or count distribution that closely matches a portion of the mask pattern. Ideally, each source direction corresponds to a unique count distribution. Using backprojection reconstruction, the source direction is determined within the field of view. The knowledge of 3D position of interaction results in improved image quality. Results: Using a single array of detectors, a coded aperture mask, and multiple Co-57 (122keV) point sources, image reconstruction is performed in real-time, on an event-by-event basis, resulting in images with an angular resolution of ∼6 degrees. Although material nonuniformities contribute to image degradation, the superposition of images from individual detectors results in improved SNR. CAI was integrated with Compton imaging for a seamless transition between energy regimes. Conclusion: For the first time, CAI has been applied to thick, 3D position sensitive CZT detectors. Real-time, combined CAI and Compton imaging is performed using two 3×3 detector arrays, resulting in a source distribution in space. This system has been commercialized by H3D, Inc. and is being acquired for

  18. Deep levels in high resistive CdTe and CdZnTe explored by photo-Hall effect and photoluminescence spectroscopy

    Science.gov (United States)

    Musiienko, Artem; Grill, Roman; Hlídek, Pavel; Moravec, Pavel; Belas, Eduard; Zázvorka, Jakub; Korcsmáros, Gabriel; Franc, Jan; Vasylchenko, Igor

    2017-01-01

    High resistive CdTe and CdZnTe single crystals were measured by photo-Hall effect spectroscopy (PHES) and photoluminescence spectroscopy (PL) with the aim of discovering the position of deep levels (DLs) in the band gap. Illumination in the range of 0.65-1.77 eV, room temperature, and DC electrical measurements were used in the case of PHES. Low temperature (4 K) photoluminescence spectra were recorded in the spectral range above 0.47 eV. Eight samples, both n-type and p-type, were studied and typical shapes of spectra were collected, compared and interpreted for both spectroscopy methods. It was shown that a simple single-level model of PHES often fails in the interpretation of DLs distant from the midgap. Eight DLs with the energy E c - 0.65 eV, E c - 0.8 eV, E c - 0.9 eV, E c - (1.10-1.15) eV, E v + 0.70 eV, E v + 0.85 eV, E v + 1.0 eV, and E c - 1.25 eV were interpreted. A memory effect characterized by a relaxation time of about 60 s was observed at the 0.8 eV level and allowed us to determine the 1.7 × 10-17 cm2 capture cross-section of electrons on this level. It is argued that PHES is a convenient complementary method to identify and characterize DLs, including DLs inaccessible by thermal emission techniques. DLs observed by PHES were consistently verified by PL.

  19. Characterization of HgCdTe Films Grown on Large-Area CdZnTe Substrates by Molecular Beam Epitaxy

    Science.gov (United States)

    Arkun, F. Erdem; Edwall, Dennis D.; Ellsworth, Jon; Douglas, Sheri; Zandian, Majid; Carmody, Michael

    2017-09-01

    Recent advances in growth of Hg1- x Cd x Te films on large-area (7 cm × 7.5 cm) CdZnTe (CZT) substrates is presented. Growth of Hg1- x Cd x Te with good uniformity on large-area wafers is achieved using a Riber 412 molecular beam epitaxy (MBE) tool designed for growth of Hg1- x Cd x Te compounds. The reactor is equipped with conventional CdTe, Te, and Hg sources for achieving uniform exposure of the wafer during growth. The composition of the Hg1- x Cd x Te compound is controlled in situ by employing a closed-loop spectral ellipsometry technique to achieve a cutoff wavelength ( λ co) of 14 μm at 78 K. We present data on the thickness and composition uniformity of films grown for large-format focal-plane array applications. The composition and thickness nonuniformity are determined to be maps show the spatial distribution of defects generated during the epitaxial growth of the Hg1- x Cd x Te films. Microdefect densities are in the low 103 cm-2 range, and void defects are below 500 cm-2. Dislocation densities less than 5 × 105 cm-2 are routinely achieved for Hg1- x Cd x Te films grown on CZT substrates. HgCdTe 4k × 4k focal-plane arrays with 15 μm pitch for astronomical wide-area infrared imagers have been produced using the recently developed MBE growth process at Teledyne Imaging Sensors.

  20. The HERMES recoil detector

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Aschenauer, E.C. [DESY, Zeuthen (Germany); Belostotski, S. [B.P. Konstantinov Petersburg Nuclear Physics Insitute, Gatchina (Russian Federation)] [and others; Collaboration: HERMES Recoil Detector Group

    2013-02-15

    For the final running period of HERA, a recoil detector was installed at the HERMES experiment to improve measurements of hard exclusive processes in charged-lepton nucleon scattering. Here, deeply virtual Compton scattering is of particular interest as this process provides constraints on generalised parton distributions that give access to the total angular momenta of quarks within the nucleon. The HERMES recoil detector was designed to improve the selection of exclusive events by a direct measurement of the four-momentum of the recoiling particle. It consisted of three components: two layers of double-sided silicon strip sensors inside the HERA beam vacuum, a two-barrel scintillating fibre tracker, and a photon detector. All sub-detectors were located inside a solenoidal magnetic field with an integrated field strength of 1Tm. The recoil detector was installed in late 2005. After the commissioning of all components was finished in September 2006, it operated stably until the end of data taking at HERA end of June 2007. The present paper gives a brief overview of the physics processes of interest and the general detector design. The recoil detector components, their calibration, the momentum reconstruction of charged particles, and the event selection are described in detail. The paper closes with a summary of the performance of the detection system.

  1. Detectors for Tomorrow's Instruments

    Science.gov (United States)

    Moseley, Harvey

    2009-01-01

    Cryogenically cooled superconducting detectors have become essential tools for a wide range of measurement applications, ranging from quantum limited heterodyne detection in the millimeter range to direct searches for dark matter with superconducting phonon detectors operating at 20 mK. Superconducting detectors have several fundamental and practical advantages which have resulted in their rapid adoption by experimenters. Their excellent performance arises in part from reductions in noise resulting from their low operating temperatures, but unique superconducting properties provide a wide range of mechanisms for detection. For example, the steep dependence of resistance with temperature on the superconductor/normal transition provides a sensitive thermometer for calorimetric and bolometric applications. Parametric changes in the properties of superconducting resonators provides a mechanism for high sensitivity detection of submillimeter photons. From a practical point of view, the use of superconducting detectors has grown rapidly because many of these devices couple well to SQUID amplifiers, which are easily integrated with the detectors. These SQUID-based amplifiers and multiplexers have matured with the detectors; they are convenient to use, and have excellent noise performance. The first generation of fully integrated large scale superconducting detection systems are now being deployed. I will discuss the prospects for a new generation of instruments designed to take full advantage of the revolution in detector technology.

  2. The Belle II Detector

    Science.gov (United States)

    Piilonen, Leo; Belle Collaboration, II

    2017-01-01

    The Belle II detector is now under construction at the KEK laboratory in Japan. This project represents a substantial upgrade of the Belle detector (and the KEKB accelerator). The Belle II experiment will record 50 ab-1 of data, a factor of 50 more than that recorded by Belle. This large data set, combined with the low backgrounds and high trigger efficiencies characteristic of an e+e- experiment, should provide unprecedented sensitivity to new physics signatures in B and D meson decays, and in τ lepton decays. The detector comprises many forefront subsystems. The vertex detector consists of two inner layers of silicon DEPFET pixels and four outer layers of double-sided silicon strips. These layers surround a beryllium beam pipe having a radius of only 10 mm. Outside of the vertex detector is a large-radius, small-cell drift chamber, an ``imaging time-of-propagation'' detector based on Cerenkov radiation for particle identification, and scintillating fibers and resistive plate chambers used to identify muons. The detector will begin commissioning in 2017.

  3. ATLAS Detector Interface Group

    CERN Multimedia

    Mapelli, L

    Originally organised as a sub-system in the DAQ/EF-1 Prototype Project, the Detector Interface Group (DIG) was an information exchange channel between the Detector systems and the Data Acquisition to provide critical detector information for prototype design and detector integration. After the reorganisation of the Trigger/DAQ Project and of Technical Coordination, the necessity to provide an adequate context for integration of detectors with the Trigger and DAQ lead to organisation of the DIG as one of the activities of Technical Coordination. Such an organisation emphasises the ATLAS wide coordination of the Trigger and DAQ exploitation aspects, which go beyond the domain of the Trigger/DAQ project itself. As part of Technical Coordination, the DIG provides the natural environment for the common work of Trigger/DAQ and detector experts. A DIG forum for a wide discussion of all the detector and Trigger/DAQ integration issues. A more restricted DIG group for the practical organisation and implementation o...

  4. Detectors - Electronics; Detecteurs - Electronique

    Energy Technology Data Exchange (ETDEWEB)

    Bregeault, J.; Gabriel, J.L.; Hierle, G.; Lebotlan, P.; Leconte, A.; Lelandais, J.; Mosrin, P.; Munsch, P.; Saur, H.; Tillier, J. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France)

    1998-04-01

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

  5. The HOTWAXS detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E.; Derbyshire, G.E. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Diakun, G. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Duxbury, D.M. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom)], E-mail: d.m.duxbury@rl.ac.uk; Fairclough, J.P.A. [Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF (United Kingdom); Harvey, I.; Helsby, W.I. [Science and Technology Facilities Council, Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington WA4 4AD (United Kingdom); Lipp, J.D.; Marsh, A.S.; Salisbury, J. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Sankar, G. [Royal Institution of GB, 21 Albemarle Street, London W1S 4BS (United Kingdom); Spill, E.J.; Stephenson, R. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom); Terrill, N.J. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2007-10-11

    The development and testing of the HOTWAXS position-sensitive X-ray detector for Synchrotron Radiation Sources is described. Funded from a facility development grant, the aim of the project was to produce a high counting rate, parallax-free photon counting detector to be used in the combined studies of X-ray absorption fine structure and X-ray diffraction (XAFS/XRD), and also in the technique of small angle and wide angle X-ray scattering (SAXS/WAXS). The detector system is described together with results of experiments carried out at the Daresbury Laboratory Synchrotron Radiation Source.

  6. Performance of GLD detector

    Indian Academy of Sciences (India)

    T Yoshioka

    2007-12-01

    Most of the important physics processes to be studied in the international linear collider (ILC) experiment have multi-jets in the final state. In order to achieve better jet energy resolution, the so-called particle flow algorithm (PFA) will be employed and there is a general consensus that PFA derives overall ILC detector design. Four detector concepts for the ILC experiment have been proposed so far in the world; the GLD detector that has a large inner calorimeter radius, which is considered to have an advantage for a PFA, is one of them. In this paper, general scheme and performance of the GLD-PFA will be presented.

  7. Microfluidic Scintillation Detectors

    CERN Multimedia

    Microfluidic scintillation detectors are devices of recent introduction for the detection of high energy particles, developed within the EP-DT group at CERN. Most of the interest for such technology comes from the use of liquid scintillators, which entails the possibility of changing the active material in the detector, leading to an increased radiation resistance. This feature, together with the high spatial resolution and low thickness deriving from the microfabrication techniques used to manufacture such devices, is desirable not only in instrumentation for high energy physics experiments but also in medical detectors such as beam monitors for hadron therapy.

  8. The Silicon Cube detector

    Energy Technology Data Exchange (ETDEWEB)

    Matea, I.; Adimi, N. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Blank, B. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France)], E-mail: blank@cenbg.in2p3.fr; Canchel, G.; Giovinazzo, J. [Centre d' Etudes Nucleaires de Bordeaux Gradignan - Universite Bordeaux 1 - UMR 5797, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Borge, M.J.G.; Dominguez-Reyes, R.; Tengblad, O. [Insto. Estructura de la Materia, CSIC, Serrano 113bis, E-28006 Madrid (Spain); Thomas, J.-C. [GANIL, CEA/DSM - CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France)

    2009-08-21

    A new experimental device, the Silicon Cube detector, consisting of six double-sided silicon strip detectors placed in a compact geometry was developed at CENBG. Having a very good angular coverage and high granularity, it allows simultaneous measurements of energy and angular distributions of charged particles emitted from unbound nuclear states. In addition, large-volume Germanium detectors can be placed close to the collection point of the radioactive species to be studied. The setup is ideally suited for isotope separation on-line (ISOL)-type experiments to study multi-particle emitters and was tested during an experiment at the low-energy beam line of SPIRAL at GANIL.

  9. ATLAS Inner Detector Alignment

    CERN Document Server

    Bocci, A

    2008-01-01

    The ATLAS experiment is a multi-purpose particle detector that will study high-energy particle collisions produced by the Large Hadron Collider at CERN. In order to achieve its physics goals, the ATLAS tracking requires that the positions of the silicon detector elements have to be known to a precision better than 10 μm. Several track-based alignment algorithms have been developed for the Inner Detector. An extensive validation has been performed with simulated events and real data coming from the ATLAS. Results from such validation are reported in this paper.

  10. Directional radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, Jonathan L.

    2017-09-12

    Directional radiation detectors and systems, methods, and computer-readable media for using directional radiation detectors to locate a radiation source are provided herein. A directional radiation detector includes a radiation sensor. A radiation attenuator partially surrounds the radiation sensor and defines an aperture through which incident radiation is received by the radiation sensor. The aperture is positioned such that when incident radiation is received directly through the aperture and by the radiation sensor, a source of the incident radiation is located within a solid angle defined by the aperture. The radiation sensor senses at least one of alpha particles, beta particles, gamma particles, or neutrons.

  11. Novel Photo-Detectors and Photo-Detector Systems

    OpenAIRE

    Danilov, M.

    2008-01-01

    Recent developments in photo-detectors and photo-detector systems are reviewed. The main emphasis is made on Silicon Photo-Multipliers (SiPM) - novel and very attractive photo-detectors. Their main features are described. Properties of detectors manufactured by different producers are compared. Different applications are discussed including calorimeters, muon detection, tracking, Cherenkov light detection, and time of flight measurements.

  12. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  13. ALICE Forward Multiplicity Detector

    CERN Multimedia

    Christensen, C

    2013-01-01

    The Forward Multiplicity Detector (FMD) extends the coverage for multiplicity of charge particles into the forward regions - giving ALICE the widest coverage of the 4 LHC experiments for these measurements.

  14. OPAL detector electromagnetic calorimeter

    CERN Multimedia

    1988-01-01

    Half of the electromagnetic calorimeter of the OPAL detector is seen in this photo. This calorimeter consists of 4720 blocks of lead glass. It was used to detect and measure the energy of photons, electrons and positrons by absorbing them.

  15. The LUX Prototype Detector

    CERN Document Server

    Akerib, D S; Bedikian, S; Bernstein, A; Bolozdynya, A; Bradley, A; Cahn, S; Carr, D; Chapman, J J; Clark, K; Classen, T; Curioni, A; Dahl, C E; Dazeley, S; deViveiros, L; Dragowsky, M; Druszkiewicz, E; Fiorucci, S; Gaitskell, R J; Hall, C; Faham, C; Holbrook, B; Kastens, L; Kazkaz, K; Kwong, J; Lander, R; Leonard, D; Malling, D; Mannino, R; McKinsey, D N; Mei, D; Mock, J; Morii, M; Nikkel, J; Phelps, P; Shutt, T; Skulski, W; Sorensen, P; Spaans, J; Steigler, T; Svoboda, R; Sweany, M; Thomson, J; Tripathi, M; Walsh, N; Webb, R; White, J; Wolfs, F L H; Woods, M; Zhang, C

    2012-01-01

    The LUX (Large Underground Xenon) detector is a two-phase xenon Time Projection Chamber (TPC) designed to search for WIMP-nucleon dark matter interactions. As with all noble element detectors, continuous purification of the detector medium is essential to produce a large ($>$1ms) electron lifetime; this is necessary for efficient measurement of the electron signal which in turn is essential for achieving robust discrimination of signal from background events. In this paper we describe the development of a novel purification system deployed in a prototype detector. The results from the operation of this prototype indicated heat exchange with an efficiency above 94% up to a flow rate of 42 slpm, allowing for an electron drift length greater than 1 meter to be achieved in approximately two days and sustained for the duration of the testing period.

  16. The CLIC Detector Concept

    CERN Document Server

    Pitters, Florian Michael

    2016-01-01

    CLIC is a concept for a future linear collider that would provide e+e- collisions at up to 3 TeV. The physics aims require a detector system with excellent jet energy and track momentum resolution, highly efficient flavour-tagging and lepton identification capabilities, full geometrical coverage extending to low polar angles and timing information in the order of nanoseconds to reject beam-induced background. To deal with those requirements, an extensive R&D programme is in place to overcome current technological limits. The CLIC detector concept includes a low-mass all-silicon vertex and tracking detector system and fine-grained calorimeters designed for particle flow analysis techniques, surrounded by a 4 T solenoid magnet. An overview of the requirements and design optimisations for the CLIC detector concept is presented.

  17. Hybrid photon detectors

    CERN Document Server

    D'Ambrosio, C

    2003-01-01

    Hybrid photon detectors detect light via vacuum photocathodes and accelerate the emitted photoelectrons by an electric field towards inversely polarized silicon anodes, where they are absorbed, thus producing electron-hole pairs. These, in turn, are collected and generate electronic signals on their ohmic contacts. This review first describes the characteristic properties of the main components of hybrid photon detectors: light entrance windows, photocathodes, and silicon anodes. Then, essential relations describing the trajectories of photoelectrons in electric and magnetic fields and their backscattering from the silicon anodes are derived. Depending on their anode configurations, three families of hybrid photon detectors are presented: hybrid photomultiplier tubes with single anodes for photon counting with high sensitivity and for gamma spectroscopy; multi-anode photon detector tubes with anodes subdivided into square or hexagonal pads for position-sensitive photon detection; imaging silicon pixel array t...

  18. GRAVITY detector systems

    Science.gov (United States)

    Mehrgan, Leander H.; Finger, Gert; Eisenhauer, Frank; Panduro, Johana

    2016-08-01

    GRAVITY is a second generation instrument for the VLT Interferometer, designed for high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the K-band. It will combine the AO corrected beams of the four VLT telescopes. In total, the GRAVITY instrument uses five eAPD detectors four for the infrared wavefront sensors of each telescope and one for the fringe tracker. In addition two Hawaii2RG arrays are installed, one for the acquisition camera and one for the spectrometer. The SAPHIRA eAPD array is a newly developed near-infrared detector with sub-electron noise performance at frame rates > 1Kfps. For all seven detectors the ESO common controller, NGC, is used. This paper presents an overview and comparison of GRAVITY detector systems and their final performances at the telescope

  19. Pocked surface neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

    2003-04-08

    The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

  20. Europe plans megaton detector

    CERN Multimedia

    Cartlidge, Edwin

    2004-01-01

    A group of French and Italian particle physicists hopes to carry on the long tradition of building large underground detectors by constructing a device deep under the Alps containing a million tonnes of extremely pure water.

  1. The pixelated detector

    CERN Multimedia

    Sutton, C

    1990-01-01

    "Collecting data as patterns of light or subatomic particles is vitally important in all the sciences. The new generation of solid-state detectors called pixel devices could transform experimental research at all levels" (4 pages).

  2. Improved CO [lidar detector

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, P.L.; Busch, G.E.; Thompson, D.C.; Remelius, D.K.; Wells, F.D.

    1999-07-18

    A high sensitivity, CO{sub 2} lidar detector, based on recent advances in ultra-low noise, readout integrated circuits (ROIC), is being developed. This detector will combine a high speed, low noise focal plane array (FPA) with a dispersive grating spectrometer. The spectrometer will filter the large background flux, thereby reducing the limiting background photon shot noise. In order to achieve the desired low noise levels, the HgCdTe FPA will be cooled to {approximately}50K. High speed, short pulse operation of the lidar system should enable the detector to operate with the order of a few noise electrons in the combined detector/ ROIC output. Current receiver design concepts will be presented, along with their expected noise performance.

  3. Detector Control System for the ATLAS Forward Proton detector

    CERN Document Server

    Czekierda, Sabina; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) is a forward detector using a Roman Pot technique, recently installed in the LHC tunnel. It is aiming at registering protons that were diffractively or electromagnetically scattered in soft and hard processes. Infrastructure of the detector consists of hardware placed both in the tunnel and in the control room USA15 (about 330 meters from the Roman Pots). AFP detector, like the other detectors of the ATLAS experiment, uses the Detector Control System (DCS) to supervise the detector and to ensure its safe and coherent operation, since the incorrect detector performance may influence the physics results. The DCS continuously monitors the detector parameters, subset of which is stored in data bases. Crucial parameters are guarded by alarm system. A detector representation as a hierarchical tree-like structure of well-defined subsystems built with the use of the Finite State Machine (FSM) toolkit allows for overall detector operation and visualization. Every node in the hierarchy is...

  4. The AMANDA Neutrino Detector

    Energy Technology Data Exchange (ETDEWEB)

    Wischnewski, R.; Andres, E.; Askebjer, P.; Barwick, S.; Bay, R.; Bergstroem, L.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Carius, S.; Carlson, M.; Chinowsky, W.; Chirkin, D.; Cowen, D.; Costa, C.; Dalberg, E.; Deyoung, T.; Edsjo, J.; Ekstroem, P.; Goobar, A.; Gray, L.; Hallgren, A.; Halzen, F.; Hardtke, R.; He, Y.; Hill, G.; Hulth, P.; Hundertmark, S.; Jacobsen, J.; Kandhadai, V.; Karle, A.; Kim, J.; Leich, H.; Leuthold, M.; Lindahl, P.; Liss, T.; Liubarsky, I.; Loaiza, P.; LOwder, D.; Marciniewski, P.; Miller, T.; Miocinovic, P.; Mock, P.; Morse, R.; Newcomer, M.; Niessen, P.; Nygren, D.; Perez de los Heros, C.; Porrata, R.; Price, P.; Przybylski, G.; Rhode, W.; Richter, S.; Rodriguez, J.; Romenesko, P.; Ross, D.; Rubinstein, H.; Schmidt, T.; Schneider, E.; Schwarz, R.; Schwendicke, U.; Smoot, G.; Solarz, M.; Sorin, V.; Spiering, C.; Steffen, P.; Stokstad, R.; Streicher, O.; Thollander, L.; Thon, T.; Tilav, S.; Walck, C.; Wiebusch, C.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S

    1999-03-01

    The first stage of the AMANDA High Energy Neutrino Detector at the South Pole, the 302 PMT array AMANDA-B with an expected effective area for TeV neutrinos of {approx} 10{sup 4} m{sup 2}, has been taking data since 1997. Progress with calibration, investigation of ice properties, as well as muon and neutrino data analysis are described. The next stage 20-string detector AMANDA-II with {approx}800 PMTs will be completed in spring 2000.

  5. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  6. Phi factory detector requirements

    Energy Technology Data Exchange (ETDEWEB)

    Arisaka, K.; Atac, M.; Berg, R.; Buchanan, C.; Calvette, M.; Khazin, B.; Kinoshita, K.; Muller, T.; Ohshima, T.; Olsen, S.; Park, J.; Santoni, C.; Shirai, J.; Solodov, E.; Thompson, J.; Triggiani, G.; Ueno, K.; Yamamoto, H.; Detector and Simulation Working Group

    1991-08-01

    We identify the experimental problems and the conditions required for successful phi-factory operation, and show the range of detector parameters which, in conjunction with different machine designs, may meet these conditions. We started by considering, comparing and criticizing the Italian and Novosibirsk designs. With this discussion as a background, we defined the apparent experimental problems and detector constraints. In this article we summarize our understanding. (orig./HSI).

  7. ATLAS Inner Detector (Pixel Detector and Silicon Tracker)

    CERN Multimedia

    ATLAS Outreach

    2006-01-01

    To raise awareness of the basic functions of the Pixel Detector and Silicon Tracker in the ATLAS detector on the LHC at CERN. This colorful 3D animation is an excerpt from the film "ATLAS-Episode II, The Particles Strike Back." Shot with a bug's eye view of the inside of the detector. The viewer is taken on a tour of the inner workings of the detector, seeing critical pieces of the detector and hearing short explanations of how each works.

  8. Detectors on the drawing board

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Linear collider detector developers inside and outside CERN are tackling the next generation of detector technology. While their focus has centred on high-energy linear collider detectors, their innovative concepts and designs will be applicable to any future detector.   A simulated event display in one of the new generation detectors. “While the LHC experiments remain the pinnacle of detector technology, you may be surprised to realise that the design and expertise behind them is well over 10 years old,” says Lucie Linssen, CERN’s Linear Collider Detector (LCD) project manager whose group is pushing the envelope of detector design. “The next generation of detectors will have to surpass the achievements of the LHC experiments. It’s not an easy task but, by observing detectors currently in operation and exploiting a decade’s worth of technological advancements, we’ve made meaningful progress.” The LCD team is curr...

  9. Effect of ZnTe and CdZnTe Alloys at the Back Contact of 1-μm-Thick CdTe Thin Film Solar Cells

    Science.gov (United States)

    Amin, Nowshad; Yamada, Akira; Konagai, Makoto

    2002-05-01

    N2-doped ZnTe was introduced onto 1-μm-thick CdTe absorbers in order to reduce the carrier recombination at the back contact of CdS/CdTe/C/Ag configuration solar cells. ZnTe films were grown by molecular beam epitaxy (MBE) on GaAs and Corning glass substrates to investigate the characteristics of the films. Epitaxial growth of ZnTe was realized on GaAs substrates and a hole concentration of 8 × 1018 cm-3 with a resistivity of 0.045 Ω \\cdotcm was achieved as a result of nitrogen doping. In contrast, polycrystalline ZnTe films were grown on Corning glass and CdTe thin films. Dark and photoconductivity of ZnTe films increased to 1.43 × 10-5 S/cm and 1.41 × 10-4 S/cm, respectively, while the Zn to Te ratio was decreased to 0.25 during MBE growth. These ZnTe films with different thicknesses were inserted into close-spaced sublimation (CSS)-grown 1-μm-thick CdTe solar cells. A conversion efficiency of 8.31% (Voc: 0.74 V, Jsc: 22.98 mA/cm2, FF: 0.49, area: 0.5 cm2) was achieved for a 0.2-μm-thick ZnTe layer with a cell configuration of CdS/CdTe/ZnTe/Cu-doped-C/Ag. Furthermore, to overcome the problem of possible recombination loss in the interface layer of CdTe and ZnTe, the intermediate ternary CdZnTe is investigated. The compositional factor in Cd1-xZnxTe:N alloy is varied and the dependence of the conductivity is evaluated. For instance, Cd0.5Zn0.5Te:N, with dark and photoconductivity of 2.13 × 10-6 and 2.9 × 10-5 S/cm, respectively, is inserted at the back contact of a 1-μm-thick CdTe solar cell. A conversion efficiency of 7.46% (Voc: 0.68 V, Jsc: 22.60 mA/cm2, FF: 0.49, area: 0.086 cm2) was achieved as the primary result for a 0.2-μm-thick Cd0.5Zn0.5Te:N layer with the cell configuration of CdS/CdTe/Cd0.5Zn0.5Te:N/Au.

  10. The ZEUS microvertex detector

    CERN Document Server

    Garfagnini, A

    1999-01-01

    A new vertex detector for the ZEUS experiment at HERA will be installed during the 1999-2000 shutdown, for the high-luminosity runs of HERA. It will allow to reconstruct secondary vertex tracks, coming from the decay of long-lived particles with a lifetime of about 10 sup - sup 1 sup 2 s, and improve the global momentum resolution of the tracking system. The interaction region will be surrounded with single-sided silicon strip detectors, with capacitive charge division: three double layers in the central region (600 detectors), and 4 'wheels' in the forward region (112 silicon planes). Due to the high number of readout channels, 512 readout strips per silicon plane in the barrel region and 480 in the forward part, and the large coverage of the vertex detector (almost 1 m long), the front-end electronics has to be placed on top of the detectors and has to be radiation tolerant since doses up to 2 kGy are expected near the interaction region. The HELIX chip has been chosen as analog chip with a low-noise, charg...

  11. Nonequilibrium superconducting detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Esposito, E.; Lisitskyi, M. P.; Nappi, C.; Pagano, S.; Perez de Lara, D.

    2006-03-01

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  12. Nonequilibrium superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, R [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Ejrnaes, M [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); INFN Sezione di Napoli, 80126 Naples (Italy); Esposito, E [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Lisitskyi, M P [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Nappi, C [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Pagano, S [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Saudi Arabia) (Italy); Perez de Lara, D [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy)

    2006-03-15

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  13. Detectors in Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Blaj, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carini, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Carron, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Haller, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hart, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hasi, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Herrmann, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kenney, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Segal, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tomada, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  14. Analysis of CZT crystals and detectors grown in Russia and the Ukraine by high-pressure Bridgman methods

    Energy Technology Data Exchange (ETDEWEB)

    H. Hermon; M. Schieber; R. B. James; E. Y. Lee; N. Yang; A. J. Antolak; D. H. Morse; C. Hackett; E. Tarver; N. N. P. Kolesnikov; Yu N. Ivanov; V. Komar; M. S. Goorsky; H. Yoon

    2000-01-10

    Sandia National Laboratories (SNL) is leading an effort to evaluate vertical high pressure Bridgman (VHPB) Cd{sub 1-x}Zn{sub x}Te (CZT) crystals grown in the former Soviet Union (FSU) (Ukraine and Russia), in order to study the parameters limiting the crystal quality and the radiation detector performance. The stoichiometry of the CZT crystals, with 0.04 < x < 0.25, has been determined by methods such as proton-induced X-ray emission (PIXE), X-ray diffraction (XRD), microprobe analysis and laser ablation ICP mass spectroscopy (LA-ICP/MS). Other methods such as triaxial double crystal x-ray diffraction (TADXRD), infrared transmission spectroscopy (IR), atomic force microscopy (AFM), thermoelectric emission spectroscopy (TEES) and laser induced transient charge technique (TCT) were also used to evaluate the material properties. The authors have measured the zinc distribution in a CZT ingot along the axial direction and also its homogeneity. The (Cd+Zn)/Te average ratio measured on the Ukraine crystals was 1.2, compared to the ratio of 0.9-1.06 on the Russian ingots. The IR transmission showed highly decorated grain boundaries with precipitates and hollow bubbles. Microprobe elemental analysis and LA-ICP/MS showed carbon precipitates in the CZT bulk and carbon deposits along grain boundaries. The higher concentration of impurities and the imperfect crystallinity lead to shorter electron and hole lifetimes in the range of 0.5--2 {micro}s and 0.1 {micro}s respectively, compared to 3--20 {micro}s and 1--7 {micro}s measured on US spectrometer grade CZT detectors. These results are consistent with the lower resistivity and worse crystalline perfection of these crystals, compared to US grown CZT. However, recently grown CZT from FSU exhibited better detector performance and good response to alpha particles.

  15. OPERA: Electronic Detector

    CERN Document Server

    Jollet, C

    2010-01-01

    OPERA is an hybrid detector for the ni-tau appearance search in a direct way, and the Electronic Detectors (ED) have the crucial role of triggerring for the neutrino events and of localizing such an interaction inside the target. Another very important task of the ED is to identify the muon since only a correct matching of such a track with a track in the emulsion connected to the vertex of the event allows to reduce the charm background to the desired level. The ED, fully working since 2006, consist of a target tracker (scintillator strips) and a spectrometer (RPC and drift tubes). The different sub-detectors are de- scribed in the poster, as well as their performance both on Monte Carlo (MC) and real data.

  16. 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.

  17. The LHCb Detector Upgrade

    CERN Document Server

    Schindler, H

    2013-01-01

    The LHCb collaboration presented a Letter of Intent (LOI) to the LHCC in March 2011 for a major upgrading of the detector during Long Shutdown 2 (2018) and intends to collect a data sample of 50/fb in the LHC and High-Luminosity-LHC eras. The aim is to operate the experiment at an instantaneous luminosity 2.5 times above the present operational luminosity, which has already been pushed to twice the design value. Reading out the detector at 40MHz allows to increase the trigger efficiencies especially for the hadronic decay modes. The physics case and the strategy for the upgrade have been endorsed by the LHCC. This paper presents briefly the physics motivations for the LHCb upgrade and the proposed changes to the detector and trigger.

  18. JSATS Detector Field Manual

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eric Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flory, Adam E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lamarche, Brian L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-06-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) Detector is a software and hardware system that captures JSATS Acoustic Micro Transmitter (AMT) signals. The system uses hydrophones to capture acoustic signals in the water. This analog signal is then amplified and processed by the Analog to Digital Converter (ADC) and Digital Signal Processor (DSP) board in the computer. This board digitizes and processes the acoustic signal to determine if a possible JSATS tag is present. With this detection, the data will be saved to the computer for further analysis. This document details the features and functionality of the JSATS Detector software. The document covers how to install the software, setup and run the detector software. The document will also go over the raw binary waveform file format and CSV files containing RMS values

  19. JSATS Detector Field Manual

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eric Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flory, Adam E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lamarche, Brian L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiland, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-06-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) Detector is a software and hardware system that captures JSATS Acoustic Micro Transmitter (AMT) signals. The system uses hydrophones to capture acoustic signals in the water. This analog signal is then amplified and processed by the Analog to Digital Converter (ADC) and Digital Signal Processor (DSP) board in the computer. This board digitizes and processes the acoustic signal to determine if a possible JSATS tag is present. With this detection, the data will be saved to the computer for further analysis. This document details the features and functionality of the JSATS Detector software. The document covers how to install the software, setup and run the detector software. The document will also go over the raw binary waveform file format and CSV files containing RMS values

  20. Cryogenic Tracking Detectors

    CERN Multimedia

    Luukka, P R; Tuominen, E M; Mikuz, M

    2002-01-01

    The recent advances in Si and diamond detector technology give hope of a simple solution to the radiation hardness problem for vertex trackers at the LHC. In particular, we have recently demonstrated that operating a heavily irradiated Si detector at liquid nitrogen (LN$_2$) temperature results in significant recovery of Charge Collection Efficiency (CCE). Among other potential benefits of operation at cryogenic temperatures are the use of large low-resistivity wafers, simple processing, higher and faster electrical signal because of higher mobility and drift velocity of carriers, and lower noise of the readout circuit. A substantial reduction in sensor cost could result The first goal of the approved extension of the RD39 program is to demonstrate that irradiation at low temperature in situ during operation does not affect the results obtained so far by cooling detectors which were irradiated at room temperature. In particular we shall concentrate on processes and materials that could significantly reduce th...

  1. The AFP Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  2. 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.

  3. Edgeless silicon pad detectors

    Science.gov (United States)

    Perea Solano, B.; Abreu, M. C.; Avati, V.; Boccali, T.; Boccone, V.; Bozzo, M.; Capra, R.; Casagrande, L.; Chen, W.; Eggert, K.; Heijne, E.; Klauke, S.; Li, Z.; Mäki, T.; Mirabito, L.; Morelli, A.; Niinikoski, T. O.; Oljemark, F.; Palmieri, V. G.; Rato Mendes, P.; Rodrigues, S.; Siegrist, P.; Silvestris, L.; Sousa, P.; Tapprogge, S.; Trocmé, B.

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in "edgeless" planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5±8 stat..±6 syst.) μm.

  4. Edgeless silicon pad detectors

    Energy Technology Data Exchange (ETDEWEB)

    Perea Solano, B. [CERN, CH-1211 Geneva 23 (Switzerland)]. E-mail: blanca.perea.solano@cern.ch; Abreu, M.C. [LIP and University of Algarve, 8000 Faro (Portugal); Avati, V. [CERN, CH-1211 Geneva 23 (Switzerland); Boccali, T. [INFN Sez. di Pisa and Scuola Normale Superiore, Pisa (Italy); Boccone, V. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Bozzo, M. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Capra, R. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Casagrande, L. [INFN Sez. di Roma 2 and Universita di Roma 2, Rome (Italy); Chen, W. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Eggert, K. [CERN, CH-1211 Geneva 23 (Switzerland); Heijne, E. [CERN, CH-1211 Geneva 23 (Switzerland); Klauke, S. [CERN, CH-1211 Geneva 23 (Switzerland); Li, Z. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Maeki, T. [Helsinki Institute of Physics, Helsinki (Finland); Mirabito, L. [CERN, CH-1211 Geneva 23 (Switzerland); Morelli, A. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Niinikoski, T.O. [CERN, CH-1211 Geneva 23 (Switzerland); Oljemark, F. [Helsinki Institute of Physics, Helsinki (Finland); Palmieri, V.G. [Helsinki Institute of Physics, Helsinki (Finland); Rato Mendes, P. [LIP and University of Algarve, 8000 Faro (Portugal); Rodrigues, S. [LIP and University of Algarve, 8000 Faro (Portugal); Siegrist, P. [CERN, CH-1211 Geneva 23 (Switzerland); Silvestris, L. [INFN Sez. Di Bari, Bari (Italy); Sousa, P. [LIP and University of Algarve, 8000 Faro (Portugal); Tapprogge, S. [Helsinki Institute of Physics, Helsinki (Finland); Trocme, B. [Institut de Physique Nucleaire, Villeurbanne (France)

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in 'edgeless' planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5{+-}8{sub stat.}.{+-}6{sub syst.}) {mu}m.

  5. Radiation Detectors and Art

    Science.gov (United States)

    Denker, Andrea

    The use of radiation detectors in the analysis of art objects represents a very special application in a true interdisciplinary field. Radiation detectors employed in this field detect, e.g., x-rays, γ-rays, β particles, and protons. Analyzed materials range from stones, metals, over porcelain to paintings. The available nondestructive and noninvasive analytical methods cover a broad range of techniques. Hence, for the sake of brevity, this chapter will concentrate on few techniques: Proton Induced X-ray Emission (PIXE) and Proton Induced γ-ray Emission (PIGE).

  6. Modelling and 3D optimisation of CdTe pixels detector array geometry - Extension to small pixels

    CERN Document Server

    Zumbiehl, A; Fougeres, P; Koebel, J M; Regal, R; Rit, C; Ayoub, M; Siffert, P

    2001-01-01

    CdTe and CdZnTe pixel detectors offer great interest for many applications, especially for medical and industrial imaging. Up to now, the material, generally, used and investigated for pixel arrays was CZT (Hamel et al., IEEE Trans. Nucl. Sci. 43 (3) (1996) 1422; Barrett et al., Phys. Rev. Lett. 75 (1) (1995) 156; Bennett et al., Nucl. Instr. and Meth. A 392 (1997) 260; Eskin et al., J. Appl. Phys. 85 (2) (1999) 647; Brunett et al., J. Appl. Phys. 86 (7) (1999) 3926; Luke, Nucl. Instr. and Meth. A 380 (1996) 232), but cadmium telluride can also be an appropriate choice, as shown here. However, we clearly demonstrate here that the optimal pixel configuration is highly dependent on the electrical transport properties of the material. Depending on the field of primary interest, either energy resolution or counting rate efficiency in the photopeak, the geometry for each case has to be optimised. For that purpose, we have developed a calculation of the signal induced onto the pixel. Two distinct parts are used: af...

  7. The Upgraded D0 Detector

    CERN Document Server

    Abazov, V M; Abolins, M; Acharya, B S; Adams, D L; Adams, M; Adams, T; Agelou, M; Agram, J L; Ahmed, S N; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Andeen, T; Anderson, J T; Anderson, S; Andrieu, B; Angstadt, R; Anosov, V; Arnoud, Y; Arov, M; Askew, A; Åsman, B; Assis-Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Babukhadia, L; Bacon, Trevor C; Badaud, F; Baden, A; Baffioni, S; Bagby, L; Baldin, B; Balm, P W; Banerjee, P; Banerjee, S; Barberis, E; Bardon, O; Barg, W; Bargassa, P; Baringer, P; Barnes, C; Barreto, J; Bartlett, J F; Bassler, U; Bhattacharjee, M; Baturitsky, M A; Bauer, D; Bean, A; Baumbaugh, B; Beauceron, S; Begalli, M; Beaudette, F; Begel, M; Bellavance, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Besson, A; Beuselinck, R; Beutel, D; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Binder, M; Biscarat, C; Bishoff, A; Black, K M; Blackler, I; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Blumenschein, U; Bockenthein, E; Bodyagin, V; Böhnlein, A; Boeriu, O; Bolton, T A; Bonamy, P; Bonifas, D; Borcherding, F; Borissov, G; Bos, K; Bose, T; Boswell, C; Bowden, M; Brandt, A; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchanan, N J; Buchholz, D; Bühler, M; Büscher, V; Burdin, S; Burke, S; Burnett, T H; Busato, E; Buszello, C P; Butler, D; Butler, J M; Cammin, J; Caron, S; Bystrický, J; Canal, L; Canelli, F; Carvalho, W; Casey, B C K; Casey, D; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapin, D; Charles, F; Cheu, E; Chevalier, L; Chi, E; Chiche, R; Cho, D K; Choate, R; Choi, S; Choudhary, B; Chopra, S; Christenson, J H; Christiansen, T; Christofek, L; Churin, I; Cisko, G; Claes, D; Clark, A R; Clement, B; Clément, C; Coadou, Y; Colling, D J; Coney, L; Connolly, B; Cooke, M; Cooper, W E; Coppage, D; Corcoran, M; Coss, J; Cothenet, A; Cousinou, M C; Cox, B; Crepe-Renaudin, S; Cristetiu, M; Cummings, M A C; Cutts, D; Da Motta, H; Das, M; Davies, B; Davies, G; Davis, G A; Davis, W; De, K; de Jong, P; De Jong, S J; De La Cruz-Burelo, E; de La Taille, C; De Oliveira Martins, C; Dean, S; Degenhardt, J D; Déliot, F; Delsart, P A; Del Signore, K; De Maat, R; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doets, M; Doidge, M; Dong, H; Doulas, S; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dvornikov, O; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Edwards, T; Ellison, J; Elmsheuser, J; Eltzroth, J T; Elvira, V D; Eno, S; Ermolov, P; Eroshin, O V; Estrada, J; Evans, D; Evans, H; Evdokimov, A; Evdokimov, V N; Fagan, J; Fast, J; Fatakia, S N; Fein, D; Feligioni, L; Ferapontov, A V; Ferbel, T; Ferreira, M J; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fleck, I; Fitzpatrick, T; Flattum, E; Fleuret, F; Flores, R; Foglesong, J; Fortner, M; Fox, H; Franklin, C; Freeman, W; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Gao, M; García, C; García-Bellido, A; Gardner, J; Gavrilov, V; Gay, A; Gay, P; Gelé, D; Gelhaus, R; Genser, K; Gerber, C E; Gershtein, Yu; Gillberg, D; Geurkov, G; Ginther, G; Gobbi, B; Goldmann, K; Golling, T; Gollub, N; Golovtsov, V L; Gómez, B; Gómez, G; Gómez, R; Goodwin, R W; Gornushkin, Y; Gounder, K; Goussiou, A; Graham, D; Graham, G; Grannis, P D; Gray, K; Greder, S; Green, D R; Green, J; Green, J A; Greenlee, H; Greenwood, Z D; Gregores, E M; Grinstein, S; Gris, P; Grivaz, J F; Groer, L; Grünendahl, S; Grünewald, M W; Gu, W; Guglielmo, J; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, G; Gutíerrez, P; Haas, A; Hadley, N J; Haggard, E; Haggerty, H; Hagopian, S; Hall, I; Hall, R E; Han, C; Han, L; Hance, R; Hanagaki, K; Hanlet, P; Hansen, S; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, C; Hays, J; Hazen, E; Hebbeker, T; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hong, S J; Hooper, R; Hou, S; Houben, P; Hu, Y; Huang, J; Huang, Y; Hynek, V; Huffman, D; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jacquier, Y; Jaffré, M; Jain, S; Jain, V; Jakobs, K; Jayanti, R; Jenkins, A; Jesik, R; Jiang, Y; Johns, K; Johnson, M; Johnson, P; Jonckheere, A; Jonsson, P; Jöstlein, H; Jouravlev, N I; Juárez, M; Juste, A; Kaan, A P; Kado, M; Käfer, D; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J; Kalmani, S D; Karmanov, D; Kasper, J; Katsanos, I; Kau, D; Kaur, R; Ke, Z; Kehoe, R; Kermiche, S; Kesisoglou, S; Khanov, A; Kharchilava, A I; Kharzheev, Yu M; Kim, H; Kim, K H; Kim, T J; Kirsch, N; Klima, B; Klute, M; Kohli, J M; Konrath, J P; Komissarov, E V; Kopal, M; Korablev, V M; Kostritskii, A V; Kotcher, J; Kothari, B; Kotwal, A V; Koubarovsky, A; Kozelov, A V; Kozminski, J; Kryemadhi, A; Kuznetsov, O; Krane, J; Kravchuk, N; Krempetz, K; Krider, J; Krishnaswamy, M R; Krzywdzinski, S; Kubantsev, M A; Kubinski, R; Kuchinsky, N; Kuleshov, S; Kulik, Y; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Kuznetsov, V E; Kwarciany, R; Lager, S; Lahrichi, N; Landsberg, G L; Larwill, M; Laurens, P; Lavigne, B; Lazoflores, J; Le Bihan, A C; Le Meur, G; Lebrun, P; Lee, S W; Lee, W M; Leflat, A; Leggett, C; Lehner, F; Leitner, R; Leonidopoulos, C; Lévêque, J; Lewis, P; Li, J; Li, Q Z; Li, X; Lima, J G R; Lincoln, D; Lindenmeyer, C; Linn, S L; Linnemann, J; Lipaev, V V; Lipton, R; Litmaath, M; Lizarazo, J; Lobo, L; Lobodenko, A; Lokajícek, M; Lounis, A; Love, P; Lü, J; Lubatti, H J; Lucotte, A; Lueking, L; Luo, C; Lynker, M; Lyon, A L; Machado, E; Maciel, A K A; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Magnan, A M; Maity, M; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Manakov, V; Mao, H S; Maravin, Y; Markley, D; Markus, M; Marshall, T; Martens, M; Martin, M; Martin-Chassard, G; Mattingly, S E K; Matulik, M; Mayorov, A A; McCarthy, R; McCroskey, R; McKenna, M; McMahon, T; Meder, D; Melanson, H L; Melnitchouk, A S; Mendes, A; Mendoza, D; Mendoza, L; Meng, X; Merekov, Y P; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Michaut, M; Miao, C; Miettinen, H; Mihalcea, D; Mikhailov, V; Miller, D; Mitrevski, J; Mokhov, N; Molina, J; Mondal, N K; Montgomery, H E; Moore, R W; Moulik, T; Muanza, G S; Mostafa, M; Moua, S; Mulders, M; Mundim, L; Mutaf, Y D; Nagaraj, P; Nagy, E; Naimuddin, M; Nang, F; Narain, M; Narasimhan, V S; Narayanan, A; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Neuenschwander, R T; Neustroev, P; Nöding, C; Nomerotski, A; Novaes, S F; Nozdrin, A; Nunnemann, T; Nurczyk, A; Nurse, E; O'Dell, V; O'Neil, D C; Oguri, V; Olis, D; Oliveira, N; Olivier, B; Olsen, J; Oshima, N; Oshinowo, B O; Oteroy-Garzon, G J; Padley, P; Papageorgiou, K; Parashar, N; Park, J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Perea, P M; Pérez, E; Peters, O; Petroff, P; Petteni, M; Phaf, L; Piegaia, R; Pleier, M A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M E; Pompos, A; Polosov, P; Pope, B G; Popkov, E; Porokhovoy, S; Prado da Silva, W L; Pritchard, W; Prokhorov, I; Prosper, H B; Protopopescu, S D; Przybycien, M B; Qian, J; Quadt, A; Quinn, B; Ramberg, E; Ramirez-Gomez, R; Rani, K J; Ranjan, K; Rao, M V S; Rapidis, P A; Rapisarda, S; Raskowski, J; Ratoff, P N; Ray, R E; Reay, N W; Rechenmacher, R; Reddy, L V; Regan, T; Renardy, J F; Reucroft, S; Rha, J; Ridel, M; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F K; Robinson, S; Rodrigues, R F; Roco, M T; Rotolo, C; Royon, C; Rubinov, P; Ruchti, R; Rucinski, R; Rud, V I; Rusakovich, N; Russo, P; Sabirov, B; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Satyanarayana, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, A D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schmitt, C; Schwanenberger, C; Schukin, A A; Schwartzman, A; Schwienhorst, R; Sen-Gupta, S; Severini, H; Shabalina, E; Shamim, M; Shankar, H C; Shary, V; Shchukin, A A; Sheahan, P; Shephard, W D; Shivpuri, R K; Shishkin, A A; Shpakov, D; Shupe, M; Sidwell, R A; Simák, V; Sirotenko, V I; Skow, D; Skubic, P L; Slattery, P F; Smith, D E; Smith, R P; Smolek, K; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, X; Song, Y; Sonnenschein, L; Sopczak, A; Sorin, V; Sosebee, M; Soustruznik, K; Souza, M; Spartana, N; Spurlock, B; Stanton, N R; Stark, J; Steele, J; Stefanik, A; Steinberg, J L; Steinbruck, G; Stevenson, K; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, M; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Sznajder, A; Talby, M; Tentindo-Repond, S; Tamburello, P; Taylor, W; Telford, P; Temple, J; Terentyev, N K; Teterin, V; Thomas, E; Thompson, J; Thooris, B; Titov, M; Toback, D; Tokmenin, V V; Tolian, C; Tomoto, M; Tompkins, D; Toole, T; Torborg, J; Touze, F; Towers, S; Trefzger, T; Trincaz-Duvoid, S; Trippe, T G; Tsybychev, D; Tuchming, B; Tully, C; Turcot, A S; Tuts, P M; Utes, M; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; Van den Berg, P J; Van Gemmeren, P; Van Kooten, R; Van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A H; Vasilyev, I A; Vaupel, M; Vaz, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Vigneault, M; Villeneuve-Séguier, F; Vishwanath, P R; Vlimant, J R; Von Törne, E; Vorobyov, A; Vreeswijk, M; Vu-Anh, T; Vysotsky, V S; Wahl, H D; Walker, R; Wallace, N; Wang, L; Wang, Z M; Warchol, J; Warsinsky, M; Watts, G; Wayne, M; Weber, M; Weerts, H; Wegner, M; Wermes, N; Wetstein, M; White, A; White, V; Whiteson, D; Wicke, D; Wijnen, T A M; Wijngaarden, D A; Wilcer, N; Willutzki, H; Wilson, G W; Wimpenny, S J; Wittlin, J; Wlodek, T; Wobisch, M; Womersley, J; Wood, D R; Wyatt, T R; Wu, Z; Xie, Y; Xu, Q; Xuan, N; Yacoob, S; Yamada, R; Yan, M; Yarema, R J; Yasuda, T; Yatsunenko, Y A; Yen, Y; Yip, K; Yoo, H D; Yoffe, F; Youn, S W; Yu, J; Yurkewicz, A; Zabi, A; Zanabria, M; Zatserklyaniy, A; Zdrazil, M; Zeitnitz, C; Zhang, B; Zhang, D; Zhang, X; Zhao, T; Zhao, Z; Zheng, H; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zitoun, R; Zmuda, T; Zutshi, V; Zviagintsev, S; Zverev, E G; Zylberstejn, A

    2005-01-01

    The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.

  8. The Upgraded D0 detector

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, D.L.; Adams, M.; Adams, T.; Agelou, M.; Agram, J.-L.; Ahmed, S.N.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G.A.; Anastasoaie, M.; Andeen, T.; Anderson, J.T.; Anderson, S.; /Buenos Aires U. /Rio de Janeiro, CBPF /Sao Paulo, IFT /Alberta U.

    2005-07-01

    The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.

  9. Status of the KEDR detector

    CERN Document Server

    Anashin, V V; Baibusinov, B O; Balashov, V; Baldin, E M; Barkov, L M; Barladyan, A K; Barnyakov, M Y; Baru, S E; Bedny, I; Beilin, D M; Blinov, A E; Blinov, V E; Bondarev, D V; Bondar, A E; Buzykaev, A R; Cantoni, P; Chilingarov, A G; Dneprovsky, L V; Eidelman, S I; Epifanov, D A; Frabetti, P L; Gaidarev, P B; Groshev, V R; Karpov, S V; Kiselev, V A; Klimenko, S G; Kolachev, G M; Kononov, S A; Kozlov, V N; Kravchenko, E A; Kulikov, V F; Kurdadze, L M; Kuzmin, A S; Kuznecov, S A; Lanni, F; Lelchuk, M Y; Leontiev, L A; Levichev, E B; Malyshev, V M; Manfredi, P F; Maslennikov, A L; Minakov, G D; Nagaslaev, V P; Naumenkov, A I; Nikitin, S A; Nomerotski, A; Onuchin, A P; Oreshkin, S B; Ovechkin, R; Palombo, F; Peleganchuk, S V; Petrosyan, S S; Pivovarov, S V; Poluektov, A O; Pospelov, G E; Protopopov, I Ya; Re, V; Romanov, L V; Root, N I; Ruban, A A; Savinov, G A; Shamov, A G; Shatilov, D; Shubin, M A; Shusharo, A I; Shwartz, B A; Sidorov, V A; Skovpen, Y I; Smakhtin, V P; Snopkov, R G; Sokolov, A V; Soukharev, A M; Talyshev, A A; Tayursky, V A; Telnov, V I; Tikhonov, Yu A; Todyshev, K Y; Usov, Y V; Vorobyev, A I; Yushkov, A N; Zatcepin, A V; Zhilich, V N

    2002-01-01

    KEDR is a general-purpose detector for experiments at the VEPP-4M e sup + e sup - -collider in the energy range 2E=2.0-12 GeV. All detector subsystems (except the aerogel Cherenkov counters) have been installed into the detector at VEPP-4M. Some preliminary data have been taken in the energy region of the J/PSI meson. The tuning of the detector and the VEPP-4M collider is in progress. Preliminary results on the detector performance are presented. The future experimental program for the KEDR detector is discussed.

  10. Status of the KEDR detector

    Energy Technology Data Exchange (ETDEWEB)

    Anashin, V.V.; Aulchenko, V.M.; Baibusinov, B.O.; Balashov, V.; Baldin, E.M.; Barkov, L.M.; Barladyan, A.K.; Barnyakov, M.Yu.; Baru, S.E.; Bedny, I.V.; Beilin, D.M.; Blinov, A.E.; Blinov, V.E.; Bondarev, D.V.; Bondar, A.E.; Buzykaev, A.R.; Cantoni, P.; Chilingarov, A.G.; Dneprovsky, L.V.; Eidelman, S.I.; Epifanov, D.A.; Frabetti, P.L.; Gaidarev, P.B.; Groshev, V.R.; Karpov, S.V.; Kiselev, V.A.; Klimenko, S.G.; Kolachev, G.M.; Kononov, S.A.; Kozlov, V.N.; Kravchenko, E.A.; Kulikov, V.F.; Kurdadze, L.M.; Kuzmin, A.S.; Kuznecov, S.A.; Lanni, F.; Lelchuk, M.Yu.; Leontiev, L.A.; Levichev, E.B.; Malyshev, V.M.; Manfredi, P.F.; Maslennikov, A.L.; Minakov, G.D.; Nagaslaev, V.P.; Naumenkov, A.; Nikitin, S.A.; Nomerotsky, A.; Onuchin, A.P.; Oreshkin, S.B.; Ovechkin, R.; Palombo, F.; Peleganchuk, S.V.; Petrosyan, S.S.; Pivovarov, S.V.; Poluektov, A.O.; Pospelov, G.E.; Protopopov, I.Ya.; Re, V.; Romanov, L.V.; Root, N.I.; Ruban, A.A.; Savinov, G.A.; Shamov, A.G.; Shatilov, D.; Shubin, M.A.; Shusharo, A.I.; Shwartz, B.A.; Sidorov, V.A.; Skovpen, Yu.I.; Smakhtin, V.P.; Snopkov, R.G.; Sokolov, A.V.; Soukharev, A.M.; Talyshev, A.A.; Tayursky, V.A.; Telnov, V.I.; Tikhonov, Yu.A. E-mail: tikhonov@cppm.in2p3.fr; Todyshev, K.Yu.; Usov, Yu.V.; Vorobyev, A.I.; Yushkov, A.N.; Zatcepin, A.V.; Zhilich, V.N

    2002-02-01

    KEDR is a general-purpose detector for experiments at the VEPP-4M e{sup +}e{sup -}-collider in the energy range 2E=2.0-12 GeV. All detector subsystems (except the aerogel Cherenkov counters) have been installed into the detector at VEPP-4M. Some preliminary data have been taken in the energy region of the J/{psi} meson. The tuning of the detector and the VEPP-4M collider is in progress. Preliminary results on the detector performance are presented. The future experimental program for the KEDR detector is discussed.

  11. Fast Detector Simulation Using Lelaps, Detector Descriptions in GODL

    Energy Technology Data Exchange (ETDEWEB)

    Langeveld, Willy; /SLAC

    2005-07-06

    Lelaps is a fast detector simulation program which reads StdHep generator files and produces SIO or LCIO output files. It swims particles through detectors taking into account magnetic fields, multiple scattering and dE/dx energy loss. It simulates parameterized showers in EM and hadronic calorimeters and supports gamma conversions and decays. In addition to three built-in detector configurations, detector descriptions can also be read from files in the new GODL file format.

  12. Pixel detector insertion

    CERN Multimedia

    CMS

    2015-01-01

    Insertion of the Pixel Tracker, the 66-million-channel device used to pinpoint the vertex of each colliding proton pair, located at the heart of the detector. The geometry of CMS is a cylinder lying on its side (22 meters long and 15 meters high in dia

  13. Sensitive hydrogen leak detector

    Science.gov (United States)

    Myneni, Ganapati Rao

    1999-01-01

    A sensitive hydrogen leak detector system using passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor.

  14. B-factory detectors

    CERN Document Server

    Marlow, D R

    2002-01-01

    The designs of the recently commissioned BaBar and Belle B-Factory detectors are described. The discussion is organized around the methods and instruments used to detect the so-called gold-plated-mode B sup 0->J/PSI K sub S decays and related modes.

  15. The BABAR Detector

    CERN Document Server

    CERN. Geneva

    2002-01-01

    BABAR, the detector for the SLAC PEP-II asymmetric e+e- B Factory operating at the upsilon 4S resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

  16. CALIBRATION OF PHOSWICH DETECTORS

    NARCIS (Netherlands)

    LEEGTE, HKW; KOLDENHOF, EE; BOONSTRA, AL; WILSCHUT, HW

    1992-01-01

    Two important aspects for the calibration of phoswich detector arrays have been investigated. It is shown that common gate ADCs can be used: The loss in particle identification due to fluctuations in the gate timing in multi-hit events can be corrected for by a simple procedure using the measured ti

  17. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

    The RPC system is operating with a very high uptime, an average chamber efficiency of about 95% and an average cluster size around 1.8. The average number of active channels is 97.7%. Eight chambers are disconnected and forty are working in single-gap mode due to high-voltage problems. The total luminosity lost due to RPCs in 2012 is 88.46 pb–1. One of the main goals of 2012 was to improve the stability of the endcap trigger that is strongly correlated to the performances of the detector, due to the 3-out-3 trigger logic. At beginning of 2011 the instability of the detector efficiency was about 10%. Detailed studies found that this was mainly due to the strong correlation between the performance of the detector and the atmospheric pressure (P). Figure XXY shows the linear correlation between the average cluster size of the endcap chamber versus P. This effect is expected for gaseous detectors and can be reduced by correcting the applied high-voltage working point (HVapp) according to the followi...

  18. Ionic smoke detectors

    CERN Document Server

    2002-01-01

    Ionic smoke detectors are products incorporating radioactive material. This article summarises the process for their commercialization and marketing, and how the activity is controlled, according to regulations establishing strict design and production requisites to guarantee the absence of radiological risk associated both with their use and their final handling as conventional waste. (Author)

  19. ALICE Silicon Pixel Detector

    CERN Multimedia

    Manzari, V

    2013-01-01

    The Silicon Pixel Detector (SPD) forms the innermost two layers of the 6-layer barrel Inner Tracking System (ITS). The SPD plays a key role in the determination of the position of the primary collision and in the reconstruction of the secondary vertices from particle decays.

  20. The CLIC Vertex Detector

    CERN Document Server

    Dannheim, D

    2015-01-01

    The precision physics needs at TeV-scale linear electron-positron colliders (ILC and CLIC) require a vertex-detector system with excellent flavour-tagging capabilities through a meas- urement of displaced vertices. This is essential, for example, for an explicit measurement of the Higgs decays to pairs of b-quarks, c-quarks and gluons. Efficient identification of top quarks in the decay t → W b will give access to the ttH-coupling measurement. In addition to those requirements driven by physics arguments, the CLIC bunch structure calls for hit tim- ing at the few-ns level. As a result, the CLIC vertex-detector system needs to have excellent spatial resolution, full geometrical coverage extending to low polar angles, extremely low material budget, low occupancy facilitated by time-tagging, and sufficient heat removal from sensors and readout. These considerations challenge current technological limits. A detector concept based on hybrid pixel-detector technology is under development for the CLIC ver- tex det...

  1. First ALICE detectors installed!

    CERN Multimedia

    2006-01-01

    Detectors to track down penetrating muon particles are the first to be placed in their final position in the ALICE cavern. The Alice muon spectrometer: in the foreground the trigger chamber is positioned in front of the muon wall, with the dipole magnet in the background. After the impressive transport of its dipole magnet, ALICE has begun to fill the spectrometer with detectors. In mid-July, the ALICE muon spectrometer team achieved important milestones with the installation of the trigger and the tracking chambers of the muon spectrometer. They are the first detectors to be installed in their final position in the cavern. All of the eight half planes of the RPCs (resistive plate chambers) have been installed in their final position behind the muon filter. The role of the trigger detector is to select events containing a muon pair coming, for instance, from the decay of J/ or Y resonances. The selection is made on the transverse momentum of the two individual muons. The internal parts of the RPCs, made o...

  2. Superconducting Single Photon Detectors

    NARCIS (Netherlands)

    Dorenbos, S.N.

    2011-01-01

    This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and fluoresc

  3. The BABAR Detector

    Energy Technology Data Exchange (ETDEWEB)

    Luth, Vera G

    2001-05-18

    BABAR, the detector for the SLAC PEP-II asymmetric e{sup +}e{sup -} B Factory operating at the {Upsilon}(4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

  4. Fire Emulator/Detector Evaluator

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The fire emulator/detector evaluator (FE/DE) is a computer-controlled flow tunnel used to re-create the environments surrounding detectors in the early...

  5. Fire Emulator/Detector Evaluator

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The fire emulator/detector evaluator (FE/DE) is a computer-controlled flow tunnel used to re-create the environments surrounding detectors in the early...

  6. Position sensitive solid state detectors

    Energy Technology Data Exchange (ETDEWEB)

    Schnatterly, S.E.; Husk, D.

    1986-05-15

    Solid state detectors have been used for years as high quantum efficiency detectors for visible light. In this paper the use of PDA and CCD, solid state detectors, in the X-ray region will be discussed. In particular examples of data in the soft X-ray region are presented. Finally the use of phosphor coatings to enhance the sensitivity of solid state detectors is described.

  7. 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)

  8. ATLAS Detector : Performance and Upgrades

    CERN Document Server

    Oliveira Damazio, Denis; The ATLAS collaboration

    2016-01-01

    Describe the ATLAS detector and summarize most relevant and recent information about the detector performance in 2016 with LHC colliding bunches at sqrt(s)=13 TeV with luminosity above the nominal value. Describe the different upgrade phases previewed for the detector and main activities already ongoing.

  9. Characterizations of GEM detector prototype

    CERN Document Server

    INSPIRE-00522505; Rudra, Sharmili; Bhattacharya, P.; Sahoo, Sumanya Sekhar; Biswas, S.; Mohanty, B.; Nayak, T.K.; Sahu, P.K.; Sahu, S.

    2016-01-01

    At NISER-IoP detector laboratory an initiative is taken to build and test Gas Electron Multiplier (GEM) detectors for ALICE experiment. The optimisation of the gas flow rate and the long-term stability test of the GEM detector are performed. The method and test results are presented.

  10. Characterisations of GEM detector prototype

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Rajendra Nath [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064, West Bengal (India); Nanda, Amit [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Rudra, Sharmili [Department of Applied Physics, CU, 92, APC Road, Kolkata 700009, West Bengal (India); Bhattacharya, P.; Sahoo, Sumanya Sekhar [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Biswas, S., E-mail: saikat.ino@gmail.com [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Mohanty, B. [School of Physical Sciences, National Institute of Science Education and Research, Jatni 752050 (India); Nayak, T.K. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064, West Bengal (India); Sahu, P.K.; Sahu, S. [Institute of Physics, Sachivalaya Marg, P.O.: Sainik School, Bhubaneswar 751005, Odisha (India)

    2016-07-11

    At NISER-IoP detector laboratory an initiative is taken to build and test Gas Electron Multiplier (GEM) detectors for ALICE experiment. The optimisation of the gas flow rate and the long-term stability test of the GEM detector are performed. The method and test results are presented.

  11. 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.

  12. Detector and System Developments for LHC Detector Upgrades

    CERN Document Server

    Mandelli, Beatrice; Guida, Roberto; Rohne, Ole; Stapnes, Steinar

    2015-05-12

    The future Large Hadron Collider (LHC) Physics program and the consequent improvement of the LHC accelerator performance set important challenges to all detector systems. This PhD thesis delineates the studies and strategies adopted to improve two different types of detectors: the replacement of precision trackers with ever increasingly performing silicon detectors, and the improvement of large gaseous detector systems by optimizing their gas mixtures and operation modes. Within the LHC tracker upgrade programs, the ATLAS Insertable B-layer (IBL) is the first major upgrade of a silicon-pixel detector. Indeed the overall ATLAS Pixel Detector performance is expected to degrade with the increase of luminosity and the IBL will recover the performance by adding a fourth innermost layer. The IBL Detector makes use of new pixel and front-end electronics technologies as well as a novel thermal management approach and light support and service structures. These innovations required complex developments and Quality Ass...

  13. Future liquid Argon detectors

    CERN Document Server

    Rubbia, A

    2013-01-01

    The Liquid Argon Time Projection Chamber offers an innovative technology for a new class of massive detectors for rare-event detection. It is a precise tracking device that allows three-dimensional spatial reconstruction with mm-scale precision of the morphology of ionizing tracks with the imaging quality of a "bubble chamber", provides $dE/dx$ information with high sampling rate, and acts as high-resolution calorimeter for contained events. First proposed in 1977 and after a long maturing process, its holds today the potentialities of opening new physics opportunities by providing excellent tracking and calorimetry performance at the relevant multi-kton mass scales, outperforming other techniques. In this paper, we review future liquid argon detectors presently being discussed by the neutrino physics community.

  14. 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...

  15. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G.Gomez

    Since September, the muon alignment system shifted from a mode of hardware installation and commissioning to operation and data taking. All three optical subsystems (Barrel, Endcap and Link alignment) have recorded data before, during and after CRAFT, at different magnetic fields and during ramps of the magnet. This first data taking experience has several interesting goals: •    study detector deformations and movements under the influence of the huge magnetic forces; •    study the stability of detector structures and of the alignment system over long periods, •    study geometry reproducibility at equal fields (specially at 0T and 3.8T); •    reconstruct B=0T geometry and compare to nominal/survey geometries; •    reconstruct B=3.8T geometry and provide DT and CSC alignment records for CMSSW. However, the main goal is to recons...

  16. The LUCID detector

    CERN Document Server

    Lasagni Manghi, Federico; The ATLAS collaboration

    2015-01-01

    Starting from 2015 LHC is performing a new run, at higher center of mass energy (13 TeV) and with 25 ns bunch-spacing. The ATLAS luminosity monitor LUCID has been completely renewed, both on detector design and in the electronics, in order to cope with the new running conditions. The new detector electronics is presented, featuring a new read-out board (LUCROD), for signal acquisition and digitization, PMT-charge integration and single-side luminosity measurements, and the revisited LUMAT board for side-A-side-C combination. The contribution covers the new boards design, the firmware and software developments, the implementation of luminosity algorithms, the optical communication between boards and the integration into the ATLAS TDAQ system.

  17. UA1 central detector

    CERN Multimedia

    The UA1 central detector was crucial to understanding the complex topology of proton-antiproton events. It played a most important role in identifying a handful of Ws and Zs among billions of collisions. The detector was a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded the tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon-ethane gas mixture filling the chambers were ionised by the passage of charged particles. The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of the 17000 field wires and 6125 sense wires allowed a spectacular 3-D interactive display of reconstructed physics events to be produced.

  18. Metrology with Unknown Detectors.

    Science.gov (United States)

    Altorio, Matteo; Genoni, Marco G; Somma, Fabrizia; Barbieri, Marco

    2016-03-11

    The best possible precision is one of the key figures in metrology, but this is established by the exact response of the detection apparatus, which is often unknown. There exist techniques for detector characterization that have been introduced in the context of quantum technologies but apply as well for ordinary classical coherence; these techniques, though, rely on intense data processing. Here, we show that one can make use of the simpler approach of data fitting patterns in order to obtain an estimate of the Cramér-Rao bound allowed by an unknown detector, and we present applications in polarimetry. Further, we show how this formalism provides a useful calculation tool in an estimation problem involving a continuous-variable quantum state, i.e., a quantum harmonic oscillator.

  19. Aerogel for FARICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Barnyakov, A.Yu. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Barnyakov, M.Yu. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, Karl Marks 20, Novosibirsk 630073 (Russian Federation); Bobrovnikov, V.S.; Buzykaev, A.R.; Gulevich, V.V. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Danilyuk, A.F. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Kononov, S.A.; Kravchenko, E.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova 2, Novosibirsk 630090 (Russian Federation); Kuyanov, I.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Lopatin, S.A. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Onuchin, A.P.; Ovtin, I.V.; Podgornov, N.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, Karl Marks 20, Novosibirsk 630073 (Russian Federation); Porosev, V.V. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Predein, A.Yu.; Protsenko, R.S. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation)

    2014-12-01

    We present our current experience in preparation of focusing aerogels for the Focusing Aerogel RICH detector. Multilayer focusing aerogel tiles have been produced in Novosibirsk by a collaboration of the Budker Institute of Nuclear Physics and Boreskov Institute of Catalysis since 2004. We have obtained 2–3–4-layer blocks with the thickness of 30–45 mm. In 2012, the first samples of focusing blocks with continuous density (refractive index) gradient along thickness were produced. This technology can significantly reduce the contribution from the geometric factor of the radiator thickness to the resolution of the measured Cherenkov angle in the FARICH detector. The special installation was used for automatic control of reagents ratio during the synthesis process. The first samples were tested using the digital radiography method and on the electron beam with the FARICH prototype.

  20. Metrology with Unknown Detectors

    CERN Document Server

    Altorio, Matteo; Somma, Fabrizia; Barbieri, Marco

    2015-01-01

    The best possible precision is one of the key figures in metrology, but this is established by the exact response of the detection apparatus, which is often unknown. There exist techniques for detector characterisation, that have been introduced in the context of quantum technologies, but apply as well for ordinary classical coherence; these techniques, though, rely on intense data processing. Here we show that one can make use of the simpler approach of data fitting patterns in order to obtain an estimate of the Cram\\'er-Rao bound allowed by an unknown detector, and present applications in polarimetry. Further, we show how this formalism provide a useful calculation tool in an estimation problem involving a continuous-variable quantum state, i.e. a quantum harmonic oscillator.

  1. Radiation damage in silicon detectors

    CERN Document Server

    Lindström, G

    2003-01-01

    Radiation damage effects in silicon detectors under severe hadron and gamma-irradiation are surveyed, focusing on bulk effects. Both macroscopic detector properties (reverse current, depletion voltage and charge collection) as also the underlying microscopic defect generation are covered. Basic results are taken from the work done in the CERN-RD48 (ROSE) collaboration updated by results of recent work. Preliminary studies on the use of dimerized float zone and Czochralski silicon as detector material show possible benefits. An essential progress in the understanding of the radiation-induced detector deterioration had recently been achieved in gamma irradiation, directly correlating defect analysis data with the macroscopic detector performance.

  2. Detectors for the space telescope

    Science.gov (United States)

    Kelsall, T.

    1978-01-01

    This review of Space Telescope (ST) detectors is divided into two parts. The first part gives short summaries of detector programs carried out during the final planning stage (Phase B) of the ST and discusses such detectors as Photicon, the MAMA detectors, the CODACON, the University of Maryland ICCD, the Goddard Space Flight Center ICCD, and the 70 mm SEC TV sensor. The second part describes the detectors selected for the first ST flight, including the wide field/planetary camera, the faint object and high resolution spectrographs, and the high speed photometer.

  3. Biological detector and method

    Energy Technology Data Exchange (ETDEWEB)

    Sillerud, Laurel; Alam, Todd M.; McDowell, Andrew F.

    2015-11-24

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  4. Biological detector and method

    Science.gov (United States)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2014-04-15

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  5. The AMANDA Neutrino Detector

    Energy Technology Data Exchange (ETDEWEB)

    Wischnewski, R.; Andres, E.; Askebjer, P.; Barwick, S.; Bay, R.; Bergstrom, L.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Carius, S.; Carlson, M.; Chinowsky, W.; Chirkin, D.; Cowen, D.; Costa, C.; Dalberg,E.; Deyoung, T.; Edsjo, J.; Ekstrom, P.; Goobar, A.; Gray, L.; Hallgren,A.; Halzen, F.; Hardtke, R.; He, Y.; Hill, G.; Hulth, P.; Hundertmark,S.; Jacobsen, J.; Kandhadai, V.; Karle, A.; Kim, J.; Leich, H.; Leuthold,M.; Lindahl, P.; Liss, T.; Liubarsky, I.; Loaiza, P.; Lowder, D.; Marciniewski, P.; Miller, T.; Miocinovic, P.; Mock, P.; Morse, R.; Newcomer, M.; Niessen, P.; Nygren, D.; de, los, Heros, CP.; Porrata, R.; Price, P.; Przybylski, G.; Rhode, W.; Richter, S.; Rodriguez, J.; Romenesko, P.; Ross, D.; Rubinstein, H.; Schmidt, T.; Schneider, E.; Schwarz, R.; Schwendicke, U.; Smoot, G.; Solarz, M.; Sorin, V.; Spiering,C.; Steffen, P.; Stokstad, R.; Streicher, O.; Thollander, L.; Thon, T.; Tilav, S.; Walck, C.; Wiebusch, C.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S.

    1999-08-23

    The first stage of the AMANDA High Energy Neutrino Detectorat the South Pole, the 302 PMT array AMANDA-B with an expected effectivearea for TeV neutrinos of similar to 10(4) m(2), has been taking datasince 1997. Progress with calibration, investigation of ice properties,as well as muon and neutrino data analysis are described. The next stage20-string detector AMANDA-II with similar to 800 PMTs will be completedin spring 2000.

  6. The ALEPH detector

    CERN Document Server

    1988-01-01

    For detecting the direction and momenta of charged particles with extreme accuracy, the ALEPH detector had at its core a time projection chamber, for years the world's largest. In the foreground from the left, Jacques Lefrancois, Jack Steinberger, Lorenzo Foa and Pierre Lazeyras. ALEPH was an experiment on the LEP accelerator, which studied high-energy collisions between electrons and positrons from 1989 to 2000.

  7. LHCb velo detector

    CERN Multimedia

    Patrice Loïez

    2001-01-01

    Photo 01 : L. to r.: D. Malinon, Summer Student, J. Libby, Fellow, J. Harvey, Head of CERN LHCb group, D. Schlatter, Head of the EP Division in front of the LHCb velo detector test beam (on the right). Photo 02 : L. to r.: J. Harvey, D. Schlatter, W. Riegler (staff), H.J. Hilke, LHCb Technical Coordinator in front of the muon chamber test beam

  8. Development of Portable Detectors

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-12-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC (the “Contractor”) and Sense Holdings, Inc. (the “Participant”) was for the development of hand-held detectors with high sensitivity and selectivity for the detection of explosives, toxic industrial chemicals and materials, and other materials of interest for security applications. The two parties built a series of demonstration and prototype handheld sensors based upon micoelectromechanical systems (MEMS) with electronic readout.

  9. Biological detector and method

    Science.gov (United States)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2013-02-26

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  10. Hybrid superconducting neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Merlo, V.; Lucci, M.; Ottaviani, I. [Dipartimento di Fisica, Università Tor Vergata, Via della Ricerca Scientifica, I-00133 Roma (Italy); Salvato, M.; Cirillo, M. [Dipartimento di Fisica, Università Tor Vergata, Via della Ricerca Scientifica, I-00133 Roma (Italy); CNR SPIN Salerno, Università di Salerno, Via Giovanni Paolo II, n.132, 84084 Fisciano (Italy); Scherillo, A. [Science and Technology Facility Council, ISIS Facility Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Celentano, G. [ENEA Frascati Research Centre, Via. E. Fermi 45, 00044 Frascati (Italy); Pietropaolo, A., E-mail: antonino.pietropaolo@enea.it [ENEA Frascati Research Centre, Via. E. Fermi 45, 00044 Frascati (Italy); Mediterranean Institute of Fundamental Physics, Via Appia Nuova 31, 00040 Marino, Roma (Italy)

    2015-03-16

    A neutron detection concept is presented that is based on superconductive niobium (Nb) strips coated by a boron (B) layer. The working principle of the detector relies on the nuclear reaction, {sup 10}B + n → α + {sup 7}Li, with α and Li ions generating a hot spot on the current-biased Nb strip which in turn induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T = 8 K and current-biased below the critical current I{sub c}, are driven into the normal state upon thermal neutron irradiation. As a result of the transition, voltage pulses in excess of 40 mV are measured while the bias current can be properly modulated to bring the strip back to the superconducting state, thus resetting the detector. Measurements on the counting rate of the device are presented and the basic physical features of the detector are discussed.

  11. MUON DETECTORS: DT

    CERN Multimedia

    M. Dallavalle.

    The DT system is ready for the LHC start up. The status of detector hardware, control and safety, of the software for calibration and monitoring and of people has been reviewed at several meetings, starting with the CMS Action Matrix Review and with the Muon Barrel Workshop (October 5 to 7). The disconnected HV channels are at a level of about 0.1%. The loss in detector acceptance because of failures in the Read-Out and Trigger electronics is about 0.5%. The electronics failure rate has been lower this year: next year will tell us whether the rate has stabilised and hopefully will confirm that the number of spares is adequate for ten years operation. Although the detector safety control is very accurate and robust, incidents have happened. In particular the DT system suffered from a significant water leak, originated in the top part of YE+1, that generated HV trips in eighteen chambers going transversely down from the top sector in YB+2 to the bottom sector in YB-2. All chambers recovered and all t...

  12. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    During data-taking in 2010 the RPC system behaviour was very satisfactory for both the detector and trigger performances. Most of the data analyses are now completed and many results and plots have been approved in order to be published in the muon detector paper. A very detailed analysis of the detector efficiency has been performed using 60 million muon events taken with the dedicated RPC monitor stream. The results have shown that the 96.3% of the system was working properly with an average efficiency of 95.4% at 9.35 kV in the Barrel region and 94.9% at 9.55 kV in the Endcap. Cluster size goes from 1.6 to 2.2 showing a clear and well-known correlation with the strip pitch. Average noise in the Barrel is less than 0.4 Hz/cm2 and about 98% of full system has averaged noise less then 1 Hz/cm2. A linear dependence of the noise versus the luminosity has been preliminary observed and is now under study. Detailed chamber efficiency maps have shown a few percent of chambers with a non-uniform efficiency distribu...

  13. UA1 prototype detector

    CERN Multimedia

    1980-01-01

    Prototype of UA1 central detector inside a plexi tube. The UA1 central detector was crucial to understanding the complex topology of proton-antiproton events. It played a most important role in identifying a handful of Ws and Zs among billions of collisions. The detector was a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded the tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon-ethane gas mixture filling the chambers were ionised by the passage of charged particles. The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of the 17000 field wires and 6125 sense wires allowed a spectacular 3-D interactive display of reconstructed physics events to be produced.

  14. The STAR PXL detector

    Science.gov (United States)

    Contin, G.

    2016-12-01

    The PiXeL detector (PXL) of the STAR experiment at RHIC is the first application of the state-of-the-art thin Monolithic Active Pixel Sensors (MAPS) technology in a collider environment. Designed to extend the STAR measurement capabilities in the heavy flavor domain, it took data in Au+Au collisions, p+p and p+Au collisions at 0√sNN=20 GeV at RHIC, during the period 2014-2016. The PXL detector is based on 50 μm-thin MAPS sensors with a pitch of 20.7 μm. Each sensor includes an array of nearly 1 million pixels, read out in rolling shutter mode in 185.6 μs. The 170 mW/cm2 power dissipation allows for air cooling and contributes to reduce the global material budget to 0.4% radiation length on the innermost layer. Experience and lessons learned from construction and operations will be presented in this paper. Detector performance and results from 2014 Au+Au data analysis, demonstrating the STAR capabilities of charm reconstruction, will be shown.

  15. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    RPC detector calibration, HV scan Thanks to the high LHC luminosity and to the corresponding high number of muons created in the first part of the 2011 the RPC community had, for the first time, the possibility to calibrate every single detector element (roll).The RPC steering committee provided the guidelines for both data-taking and data analysis and a dedicated task force worked from March to April on this specific issue. The main goal of the RPC calibration was to study the detector efficiency as a function of high-voltage working points, fit the obtained “plateau curve” with a sigmoid function and determine the “best” high-voltage working point of every single roll. On 18th and 19th March, we had eight runs at different voltages. On 27th March, the full analysis was completed, showing that 60% of the rolls had already a very good fit with an average efficiency greater than 93% in the plateau region. To improve the fit we decided to take three more runs (15th April...

  16. Commissioning the SNO+ detector

    Science.gov (United States)

    Descamps, Freija; SNO+ Collaboration

    2016-09-01

    The SNO+ experiment is the successor to the Sudbury Neutrino Observatory (SNO), in which SNO's heavy water is replaced by approximately 780T of liquid scintillator (LAB). The combination of the 2km underground location, the use of ultra-clean materials and the high light-yield of the liquid scintillator means that a low background level and a low energy threshold can be achieved. This creates a new multipurpose neutrino detector with the potential to address a diverse set of physics goals, including the detection of reactor, solar, geo- and supernova neutrinos. A main physics goal of SNO+ is the search for neutrinoless double beta decay. By loading the liquid scintillator with 0.5% of natural Tellurium, resulting in about 1300kg of 130Te (isotopic abundance is slightly over 34%), a competitive sensitivity to the effective neutrino mass can be reached. This talk will present the status of the SNO+ detector, specifically the results and status of the detector commissioning with water.

  17. Achieving subpixel resolution with time-correlated transient signals in pixelated CdZnTe gamma-ray sensors using a focused laser beam (Conference Presentation)

    Science.gov (United States)

    Ocampo Giraldo, Luis A.; Bolotnikov, Aleksey E.; Camarda, Giuseppe S.; Cui, Yonggang; De Geronimo, Gianluigi; Gul, Rubi; Fried, Jack; Hossain, Anwar; Unlu, Kenan; Vernon, Emerson; Yang, Ge; James, Ralph B.

    2017-05-01

    High-resolution position-sensitive detectors have been proposed to correct response non-uniformities in Cadmium Zinc Telluride (CZT) crystals by virtually subdividing the detectors area into small voxels and equalizing responses from each voxel. 3D pixelated detectors coupled with multichannel readout electronics are the most advanced type of CZT devices offering many options in signal processing and enhancing detector performance. One recent innovation proposed for pixelated detectors is to use the induced (transient) signals from neighboring pixels to achieve high sub-pixel position resolution while keeping large pixel sizes. The main hurdle in achieving this goal is the relatively low signal induced on the neighboring pixels because of the electrostatic shielding effect caused by the collecting pixel. In addition, to achieve high position sensitivity one should rely on time-correlated transient signals, which means that digitized output signals must be used. We present the results of our studies to measure the amplitude of the pixel signals so that these can be used to measure positions of the interaction points. This is done with the processing of digitized correlated time signals measured from several adjacent pixels taking into account rise-time and charge-sharing effects. In these measurements we used a focused pulsed laser to generate a 10-micron beam at one milliwatt (650-nm wavelength) over the detector surface while the collecting pixel was moved in cardinal directions. The results include measurements that present the benefits of combining conventional pixel geometry with digital pulse processing for the best approach in achieving sub-pixel position resolution with the pixel dimensions of approximately 2 mm. We also present the sub-pixel resolution measurements at comparable energies from various gamma emitting isotopes.

  18. The STAR Vertex Position Detector

    CERN Document Server

    Llope, W J; Nussbaum, T; Hoffmann, G W; Asselta, K; Brandenburg, J D; Butterworth, J; Camarda, T; Christie, W; Crawford, H J; Dong, X; Engelage, J; Eppley, G; Geurts, F; Hammond, J; Judd, E; McDonald, D L; Perkins, C; Ruan, L; Scheblein, J; Schambach, J J; Soja, R; Xin, K; Yang, C

    2014-01-01

    The 2x3 channel pseudo Vertex Position Detector (pVPD) in the STAR experiment at RHIC has been upgraded to a 2x19 channel detector in the same acceptance, called the Vertex Position Detector (VPD). This detector is fully integrated into the STAR trigger system and provides the primary input to the minimum-bias trigger in Au+Au collisions. The information from the detector is used both in the STAR Level-0 trigger and offline to measure the location of the primary collision vertex along the beam pipe and the event "start time" needed by other fast-timing detectors in STAR. The offline timing resolution of single detector channels in full-energy Au+Au collisions is ~100 ps, resulting in a start time resolution of a few tens of picoseconds and a resolution on the primary vertex location of ~1 cm.

  19. Crystal Growth, Characterization and Fabrication of Cadmium Zinc Telluride-based Nuclear Detectors

    Science.gov (United States)

    Krishna, Ramesh M.

    In today's world, nuclear radiation is seeing more and more use by humanity as time goes on. Nuclear power plants are being built to supply humanity's energy needs, nuclear medical imaging is becoming more popular for diagnosing cancer and other diseases, and control of weapons-grade nuclear materials is becoming more and more important for national security. All of these needs require high-performance nuclear radiation detectors which can accurately measure the type and amount of radiation being used. However, most current radiation detection materials available commercially require extensive cooling, or simply do not function adequately for high-energy gamma-ray emitting nuclear materials such as uranium and plutonium. One of the most promising semiconductor materials being considered to create a convenient, field-deployable nuclear detector is cadmium zinc telluride (CdZnTe, or CZT). CZT is a ternary semiconductor compound which can detect high-energy gamma-rays at room temperature. It offers high resistivity (≥ 1010 O-cm), a high band gap (1.55 eV), and good electron transport properties, all of which are required for a nuclear radiation detector. However, one significant issue with CZT is that there is considerable difficulty in growing large, homogeneous, defect-free single crystals of CZT. This significantly increases the cost of producing CZT detectors, making CZT less than ideal for mass-production. Furthermore, CZT suffers from poor hole transport properties, which creates significant problems when using it as a high-energy gamma-ray detector. In this dissertation, a comprehensive investigation is undertaken using a successful growth method for CZT developed at the University of South Carolina. This method, called the solvent-growth technique, reduces the complexity required to grow detector-grade CZT single crystals. It utilizes a lower growth temperature than traditional growth methods by using Te as a solvent, while maintaining the advantages of

  20. High Pressure XENON Gamma-Ray Spectrometers for Field Use

    Energy Technology Data Exchange (ETDEWEB)

    David K. Wehe; Zong He; Glenn K. Knoll

    2004-02-16

    This project explored a new concept for high-pressure xenon ionization chambers by replacing the Frisch grid with coplanar grid electrodes similar to those used in wide bandgap semiconductor gamma-ray spectrometers. This work is the first attempt to apply the coplanar grid anode design in a gas ionization chamber in order to achieve to improved energy resolution. Three prototype detectors, two cylindrical and one parallel plate configurations, were built and tested. While the detectors did not demonstrate energy resolutions as good as other high pressure xenon gamma-ray spectrometers, the results demonstrated that the concept of single polarity charge sending using coplanar grid electrodes will work in a gas detector.

  1. The DELPHI Detector (DEtector with Lepton Photon and Hadron Identification)

    CERN Multimedia

    Crawley, B; Munich, K; Mckay, R; Matorras, F; Joram, C; Malychev, V; Behrmann, A; Van dam, P; Drees, J K; Stocchi, A; Adam, W; Booth, P; Bilenki, M; Rosenberg, E I; Morton, G; Rames, J; Hahn, S; Cosme, G; Ventura, L; Marco, J; Tortosa martinez, P; Monge silvestri, R; Moreno, S; Phillips, H; Alekseev, G; Boudinov, E; Martinez rivero, C; Gitarskiy, L; Davenport, M; De clercq, C; Firestone, A; Myagkov, A; Belous, K; Haider, S; Hamilton, K M; Lamsa, J; Rahmani, M H; Malek, A; Hughes, G J; Peralta, L; Carroll, L; Fuster verdu, J A; Cossutti, F; Gorn, L; Yi, J I; Bertrand, D; Myatt, G; Richard, F; Shapkin, M; Hahn, F; Ferrer soria, A; Reinhardt, R; Renton, P; Sekulin, R; Timmermans, J; Baillon, P

    2002-01-01

    % DELPHI The DELPHI Detector (Detector with Lepton Photon and Hadron Identification) \\\\ \\\\DELPHI is a general purpose detector for physics at LEP on and above the Z$^0$, offering three-dimensional information on curvature and energy deposition with fine spatial granularity as well as identification of leptons and hadrons over most of the solid angle. A superconducting coil provides a 1.2~T solenoidal field of high uniformity. Tracking relies on the silicon vertex detector, the inner detector, the Time Projection Chamber (TPC), the outer detector and forward drift chambers. Electromagnetic showers are measured in the barrel with high granularity by the High Density Projection Chamber (HPC) and in the endcaps by $ 1 ^0 $~x~$ 1 ^0 $ projective towers composed of lead glass as active material and phototriode read-out. Hadron identification is provided mainly by liquid and gas Ring Imaging Counters (RICH). The instrumented magnet yoke serves for hadron calorimetry and as filter for muons, which are identified in t...

  2. Scintillating fiber detector

    CERN Document Server

    Vozak, Matous

    2016-01-01

    NA61 is one of the physics experiments at CERN dedicated to study hadron states coming from interactions of SPS beams with various targets. To determine the position of a secondary beam, three proportional chambers are placed along the beamline. However, these chambers tend to have slow response. In order to obtain more precise time information, use of another detector is being considered. Fast response and compact size is making scintillation fiber (SciFi) with silicon photomultiplier (Si-PM) read out a good candidate. This report is focused on analysing data from SciFi collected in a test beam at the beginning of July 2016.

  3. The ATLAS Detector Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Clark, P.J. [University of Edinburgh, School of Physics and Astronomy, James Clerk Maxwell Building, The Kings Buildings, Mayfield Road, Edinburgh EH9 3JZ (United Kingdom)

    2011-06-15

    We present the simulation software for the ATLAS experiment [G. Aad et al., The ATLAS Experiment at the CERN Large Hadron Collider, JINST 3 (2008), S08003] at the Large Hadron Collider [L. Evans and P. Bryant, LHC Machine, JINST 3 (2008), S08001]. The overall infrastructure and some selected features are discussed. In particular, the detector description, the interface to Geant4, event generator support, magnetic field integration improvements, pile-up and digitisation of overlapping events and fast simulation. Also described are performance studies, large scale production and the validation of the simulated output against recent data.

  4. The WELL Detector

    CERN Document Server

    Bellazzini, R; Brez, A; Gariano, G; Latronico, L; Lumb, N; Papanestis, A; Spandre, G; Massai, M M; Raffo, R; Spezziga, M A

    1999-01-01

    We introduce the WELL detector, a new type of position-sensitive gas proportional counter produced using advanced printed circuit board (PCB) technology. The WELL is based on a thin kapton foil, copp erclad on both sides. Charge amplifying micro-wells are etched into the first metal and kapton layers. These end on a micro-strip pattern which is defined on the second metal plane. The array of micr o-strips is used for read-out to obtain 1-D positional information. First results from our systematic assessment of this device are reported.

  5. 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.

  6. Microstructured silicon radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat; Derzon, Mark S.; Draper, Bruce L.

    2017-03-14

    A radiation detector comprises a silicon body in which are defined vertical pores filled with a converter material and situated within silicon depletion regions. One or more charge-collection electrodes are arranged to collect current generated when secondary particles enter the silicon body through walls of the pores. The pores are disposed in low-density clusters, have a majority pore thickness of 5 .mu.m or less, and have a majority aspect ratio, defined as the ratio of pore depth to pore thickness, of at least 10.

  7. PHENIX inner detectors

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M.; Bennett, M.J.; Bobrek, M.; Boissevain, J.B.; Boose, S.; Bosze, E.; Britton, C.; Chang, J.; Chi, C.Y.; Chiu, M.; Conway, R.; Cunningham, R.; Denisov, A.; Deshpande, A.; Emery, M.S.; Enokizono, A.; Ericson, N.; Fox, B.; Fung, S.-Y.; Giannotti, P.; Hachiya, T.; Hansen, A.G.; Homma, K.; Jacak, B.V.; Jaffe, D.; Kang, J.H.; Kapustinsky, J.; Kim, S.Y.; Kim, Y.G.; Kohama, T.; Kroon, P.J.; Lenz, W.; Longbotham, N.; Musrock, M.; Nakamura, T.; Ohnishi, H.; Ryu, S.S.; Sakaguchi, A.; Seto, R.; Shiina, T.; Simpson, M.; Simon-Gillo, J.; Sondheim, W.E.; Sugitate, T.; Sullivan, J.P. E-mail: sullivan@lanl.gov; Hecke, H.W. van; Walker, J.W.; White, S.N.; Willis, P.; Xu, N

    2003-03-01

    The timing, location and particle multiplicity of a PHENIX collision are determined by the Beam-Beam Counters (BBC), the Multiplicity/Vertex Detector (MVD) and the Zero-Degree Calorimeters (ZDC). The BBCs provide both the time of interaction and position of a collision from the flight time of prompt particles. The MVD provides a measure of event particle multiplicity, collision vertex position and fluctuations in charged particle distributions. The ZDCs provide information on the most grazing collisions. A Normalization Trigger Counter (NTC) is used to obtain absolute cross-section measurements for p-p collisions. The BBC, MVD and NTC are described below.

  8. CdZnTe个人剂量计能响特性的Monte Carlo模拟%Monte Carlo simulations of the energy response of γ-ray dosimeters with CdZnTe semiconductor detectors

    Institute of Scientific and Technical Information of China (English)

    康玺; 李君利; 曾志; 武祯

    2007-01-01

    为了获得合适的CdZnTe(CZT)个人剂量计的剂量-能量响应补偿方案,利用Monte Carlo程序MCNP4C对CZT、CZT加各种补偿物质和CZT在不同电子学下阀的剂量-能量响应特性进行了模拟计算.通过模拟得到了2种CZT个人剂量计剂量补偿方案:在CZT(5mm×5 mm×5mm)前加15 mm Pb(带有阶梯孔)和2 mm Pb(带有孔面积为Pb截面面积3%的孔,并分高、低能两能量道计数).为今后的CZT个人剂量计设计提供了理论依据.

  9. Estudo comparativo de detectores de HPGe, NaI(TI), CdZnTe para aplicações em segurança e para resposta a ameaças nucleares e radiológicas

    OpenAIRE

    Marques, Luís Miguel Cabeça

    2011-01-01

    Tese de mestrado em Engenharia Física, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011 Após ataques terroristas recentes, aumentou a preocupação internacional sobre as ameaças de índole nuclear e radiológica (NR), associadas ao tráfico ilícito não apenas de materiais nucleares e à sua possível aplicação em engenhos nucleares improvisados, mas também de outros materiais radioactivos (utilizados em aplicações na indústria, medicina e investigação) de possível apl...

  10. The Summarization of Passivation Techniques on CdTe and CdZnTe Room-tempreture Detectors%CdTe和CdZnTe室温探测器钝化方法概述

    Institute of Scientific and Technical Information of China (English)

    赵晓燕; 鲁正雄

    2005-01-01

    CdTe和CdZnTe是X射线和γ射线探测器最理想的材料.钝化可以降低CdTe和CdZnTe的表面漏电流,提高其能量分辨率.本文综述了CdTe和CdZnTe的H2O2湿法钝化方法和热氧化、氧离子钝化、氧离子/SiNx钝化等干法钝化方法.

  11. Infrared detectors for space applications

    Science.gov (United States)

    Fick, Wolfgang; Gassmann, Kai Uwe; Haas, Luis-Dieter; Haiml, Markus; Hanna, Stefan; Hübner, Dominique; Höhnemann, Holger; Nothaft, Hans-Peter; Thöt, Richard

    2013-12-01

    The motivation and intended benefits for the use of infrared (IR) detectors for space applications are highlighted. The actual status of state-of-the-art IR detectors for space applications is presented based on some of AIM's currently ongoing focal plane detector module developments covering the spectral range from the short-wavelength IR (SWIR) to the long-wavelength IR (LWIR) and very long-wavelength IR (VLWIR), where both imaging and spectroscopy applications will be addressed. In particular, the integrated detector cooler assemblies for a mid-wavelength IR (MWIR) push-broom imaging satellite mission, for the German hyperspectral satellite mission EnMAP and the IR detectors for the Sentinel 3 SLSTR will be elaborated. Additionally, dedicated detector modules for LWIR/VLWIR sounding, providing the possibility to have two different PVs driven by one ROIC, will be addressed.

  12. Scalar top study: Detector optimization

    Indian Academy of Sciences (India)

    C Milsténe; A Sopczak

    2007-11-01

    A vertex detector concept of the linear collider flavour identification (LCFI) collaboration, which studies pixel detectors for heavy quark flavour identification, has been implemented in simulations for -quark tagging in scalar top studies. The production and decay of scalar top quarks (stops) is particularly interesting for the development of the vertex detector as only two -quarks and missing energy (from undetected neutralinos) are produced for light stops. Previous studies investigated the vertex detector design in scenarios with large mass differences between stop and neutralino, corresponding to large visible energy in the detector. In this study we investigate the tagging performance dependence on the vertex detector design in a scenario with small visible energy for the international linear collider (ILC).

  13. Digital detectors for electron microscopy

    CERN Document Server

    Faruqi, A R

    2002-01-01

    Film has traditionally been used for recording images in transmission electron microscopes but there is an essential need for computer-interfaced electronic detectors. Cooled-CCD detectors, developed over the past few years, though not ideal, are increasingly used as the preferred detection system in a number of applications. We describe briefly the design of CCD-based detectors, along with their main properties, which have been used in electron crystallography. A newer detector design with a much bigger sensitive area, incorporating a 2x2 tiled array of CCDs with tapered fibre optics will overcome some of the limitations of existing CCD detectors. We also describe some preliminary results for 8 keV imaging, from (direct detection) silicon hybrid pixel detectors, which offer advantages over CCDs in terms of better spatial resolution, faster readout with minimal noise.

  14. 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 ...

  15. The FastGas detector

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, J.E.; Dalgliesh, R.M. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Duxbury, D.M., E-mail: dom.duxbury@stfc.ac.u [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Holt, S.A.; McPhail, D.J. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Marsh, A.S. [Diamond Light Source LTD, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Rhodes, N.J.; Schooneveld, E.M.; Spill, E.J.; Stephenson, R. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

    2010-04-21

    The development and testing of the FastGas neutron detector is described. Based on a Gas Microstrip Chamber the aim of the project was to produce a high counting rate detector capable of replacing the existing {sup 3}He tubes for specular reflectometry, currently in use on the ISIS reflectometer instruments. The detector system is described together with results of neutron beam tests carried out at the ISIS spallation neutron source.

  16. The 4th concept detector

    Indian Academy of Sciences (India)

    John Hauptman

    2007-12-01

    The 4th concept detector consists of four detector subsystems, a small-pixel vertex detector, a high-resolution TPC, a new multiple-readout fiber calorimeter and a new dual-solenoid iron-free muon system. We discuss the design of a comprehensive facility that measures and identifies all partons of the standard model, including hadronic → and → decays, with high precision and high e±ciency. We emphasis here the calorimeter and muon systems.

  17. First detectors at the ISR

    CERN Multimedia

    1971-01-01

    Some of the first detectors at the ISR. A CERN/Rome team was looking at proton scattering at very small angles to the beam direction. A detector known as a "Roman pot" is in the foreground on the left. An Aachen/CERN/Genoa/Harvard/Turin team was looking at wider angles with the detectors seen branching off from the rings on the right.

  18. Decoherence of the Unruh detector

    CERN Document Server

    Demers, G

    1995-01-01

    As it is well known, the Minkowski vacuum appears thermally populated to a quantum mechanical detector on a uniformly accelerating course. We investigate how this thermal radiation may contribute to the classical nature of the detector's trajectory through the criteria of decoherence. An uncertainty-type relation is obtained for the detector involving the fluctuation in temperature, the time of flight and the coupling to the bath.

  19. The CMS detector before closure

    CERN Multimedia

    Patrice Loiez

    2006-01-01

    The CMS detector before testing using muon cosmic rays that are produced as high-energy particles from space crash into the Earth's atmosphere generating a cascade of energetic particles. After closing CMS, the magnets, calorimeters, trackers and muon chambers were tested on a small section of the detector as part of the magnet test and cosmic challenge. This test checked the alignment and functionality of the detector systems, as well as the magnets.

  20. Development activities of a CdTe/CdZnTe pixel detector for gamma-ray spectrometry with imaging and polarimetry capability in astrophysics

    Science.gov (United States)

    Gálvez, J. L.; Hernanz, M.; Álvarez, J. M.; Álvarez, L.; La Torre, M.; Caroli, E.; Lozano, M.; Pellegrini, G.; Ullán, M.; Cabruja, E.; Martínez, R.; Chmeissani, M.; Puigdengoles, C.

    2013-05-01

    In the last few years we have been working on feasibility studies of future instruments in the gamma-ray range, from several keV up to a few MeV, in collaboration with other research institutes. High sensitivities are essential to perform detailed studies of cosmic explosions and cosmic accelerators, e.g., Supernovae, Classical Novae, Supernova Remnants (SNRs), Gamma-Ray Bursts (GRBs), Pulsars, Active Galactic Nuclei (AGN).Cadmium Telluride (CdTe) and Cadmium Zinc Telluride (CdZnTe) are very attractive materials for gamma-ray detection, since they have already demonstrated their great performance onboard current space missions, such as IBIS/INTEGRAL and BAT/SWIFT, and future projects like ASIM onboard the ISS. However, the energy coverage of these instruments is limited up to a few hundred keV, and there has not been yet a dedicated instrument for polarimetry.Our research and development activities aim to study a gamma-ray imaging spectrometer in the MeV range based on CdTe detectors, suited either for the focal plane of a focusing mission or as a calorimeter for a Compton camera. In addition, our undergoing detector design is proposed as the baseline for the payload of a balloon-borne experiment dedicated to hard X- and soft gamma-ray polarimetry, currently under study and called CμSP (CZT μ-Spectrometer Polarimeter). Other research institutes such as INAF-IASF, DTU Space, LIP, INEM/CNR, CEA, are involved in this proposal. We will report on the main features of the prototype we are developing at the Institute of Space Sciences, a gamma-ray detector with imaging and polarimetry capabilities in order to fulfil the combined requirement of high detection efficiency with good spatial and energy resolution driven by the science.

  1. MUON DETECTORS: CSC

    CERN Multimedia

    Richard Breedon

    Following the opening of the CMS detector, commissioning of the cathode strip chamber (CSC) system resumed in earnest. Some on-chamber electronics problems could be fixed on the positive endcap when each station became briefly accessible as the steel yokes were peeled off. There was no opportunity to work on the negative endcap chambers during opening; this had to wait instead until the yokes were again separated and the stations accessible during closing. In March, regular detector-operating shifts were resumed every weekday evening during which Local Runs were taken using cosmic rays to monitor and validate repairs and improvements that had taken place during the day. Since April, the CSC system has been collecting cosmic data under shift supervision 24 hours a day on weekdays, and 24/7 operation began in early June. The CSC system arranged shifts for continuous running in the entire first half of 2009. One reward of this effort is that every chamber of the CSC system is alive and recording events. There...

  2. ATLAS Detector Upgrade Prospects

    Science.gov (United States)

    Dobre, M.; ATLAS Collaboration

    2017-01-01

    After the successful operation at the centre-of-mass energies of 7 and 8 TeV in 2010-2012, the LHC was ramped up and successfully took data at the centre-of-mass energies of 13 TeV in 2015 and 2016. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, which will deliver of the order of five times the LHC nominal instantaneous luminosity along with luminosity levelling. The ultimate goal is to extend the dataset from about few hundred fb ‑1 expected for LHC running by the end of 2018 to 3000 fb ‑1 by around 2035 for ATLAS and CMS. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tracker, significant upgrades of the calorimeter and muon systems, as well as improved triggers and data acquisition. ATLAS is also examining potential benefits of extensions to larger pseudorapidity, particularly in tracking and muon systems. This report summarizes various improvements to the ATLAS detector required to cope with the anticipated evolution of the LHC luminosity during this decade and the next. A brief overview is also given on physics prospects with a pp centre-of-mass energy of 14 TeV.

  3. MUON DETECTORS: CSC

    CERN Multimedia

    J. Hauser

    2011-01-01

    The earliest collision data in 2011 already show that the CSC detector performance is very similar to that seen in 2010. That is discussed in the DPG write-up elsewhere in this Bulletin. This report focuses on a few operational developments, the ME1/1 electronics replacement project, and the preparations at CERN for building the fourth station of CSC chambers ME4/2. During the 2010 LHC run, the CSC detector ran smoothly for the most part and yielded muon triggers and data of excellent quality. Moreover, no major operational problems were found that needed to be fixed during the Extended Technical Stop. Several improvements to software and configuration were however made. One such improvement is the automation of recovery from chamber high-voltage trips. The algorithm, defined by chamber experts, uses the so-called "Expert System" to analyse the trip signals sent from DCS and, based on the frequency and the timing of the signals, respond appropriately. This will make the central DCS shifters...

  4. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli

    During the last 3 months the RPC group has made impressive improvements in the refinement of the operation tools and understanding of the detector. The full barrel and part of the plus end cap participated systematically to global runs producing millions of trigger on cosmics. The main monitoring tools were robust and efficient in controlling the detector and in diagnosis of problems. After the refinement of the synchronization procedure, detailed studies of the chamber performances, as a function of high voltage and front-end threshold, were pursued. In parallel, new tools for the prompt analysis were developed which have enabled a fast check of the data at the CMS Centre. This effort has been very valuable since it has helped in discovering many minor bugs in the reconstruction software and database which are now being fixed. Unfortunately, a large part of the RE2 station has developed increasing operational current. Some preliminary investigation leads to the conclusion that the serial gas circulation e...

  5. MUON DETECTORS: DT

    CERN Multimedia

    Marco Dallavalle

    2013-01-01

    The DT group is undertaking substantial work both for detector maintenance and for detec-tor upgrade. Maintenance interventions on chambers and minicrates require close collaboration between DT, RPC and HO, and are difficult because they depend on the removal of thermal shields and cables on the front and rear of the chambers in order to gain access. The tasks are particularly critical on the central wheel due to the presence of fixed services. Several interventions on the chambers require extraction of the DT+RPC package: a delicate operation due to the very limited space for handling the big chambers, and the most dangerous part of the DT maintenance campaign. The interventions started in July 2013 and will go on until spring 2014. So far out of the 16 chambers with HV problems, 13 have been already repaired, with a global yield of 217 recovered channels. Most of the observed problems were due to displacement of impurities inside the gaseous volume. For the minicrates and FE, repairs occurred on 22 chambe...

  6. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli.

    Substantial progress has been made on the RPC system resulting in a high standard of operation. Impressive improvements have been made in the online software and DCS PVSS protocols that ensure robustness of the configuration phase and reliability of the detector monitoring tasks. In parallel, an important upgrade of CCU ring connectivity was pursued to avoid noise pick-up and consequent  data transmission errors during operation with magnetic field. While the barrel part is already well synchronized thanks to the long cosmics runs, some refinements are still required on the forward part. The "beam splashes" have been useful to cross check  the existing delay constants, but further efforts will be made as soon as a substantial sample of beam-halo events is available. Progress has been made on early detector performance studies. The RPC DQM tool is being extensively used and minor bugs have been found. More plots have been added and more people have been tr...

  7. PAU camera: detectors characterization

    Science.gov (United States)

    Casas, Ricard; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Jiménez, Jorge; Maiorino, Marino; Pío, Cristóbal; Sevilla, Ignacio; de Vicente, Juan

    2012-07-01

    The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

  8. Advanced Radiation Detector Development

    Energy Technology Data Exchange (ETDEWEB)

    The University of Michigan

    1998-07-01

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

  9. MUON DETECTORS: DT

    CERN Multimedia

    C. Fernandez Bedoya and M. Dallavalle

    2010-01-01

    The DT system operation since the 2010 LHC start up is remarkably smooth.
 All parts of the system have behaved very satisfactorily in the last two months of operation with LHC pp collisions. Disconnected HV channels remain at the level of 0.1%, and the loss in detector acceptance because of failures in the readout and Trigger electronics is about 0.4%. The DT DCS-LHC handshake mechanism, which was strengthened after the short 2009 LHC run, operates without major problems. A problem arose with the opto-receivers of the trigger links connecting the detector to USC; the receivers would unlock from transmission for specific frequencies of the LHC lock, in particular during the LHC ramp. For relocking the TX and RX a “re-synch” command had to be issued. The source of the problem has been isolated and cured in the Opto-RX boards and now the system is stable. The Theta trigger chain also has been commissioned and put in operation. Several interventions on the system have been made, pro...

  10. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    The RPC muon detector and trigger are working very well, contributing positively to the high quality of CMS data. Most of 2011 has been used to improve the stability of our system and the monitoring tools used online and offline by the shifters and experts. The high-voltage working point is corrected, chamber-by-chamber, for pressure variation since July 2011. Corrections are applied at PVSS level during the stand-by mode (no collision) and are not changed until the next fill. The single detector calibration, HV scan, of February and the P-correction described before were very important steps towards fine-tuning the stability of the RPC performances. A very detailed analysis of the RPC performances is now ongoing and from preliminary results we observe an important improvements of the cluster size stability in time. The maximum oscillation of the cluster size run by run is now about 1%. At the same time we are not observing the same stability in the detection efficiency that shows an oscillation of about ...

  11. MUON DETECTORS: DT

    CERN Document Server

    Marco Dallavalle

    2012-01-01

      Although the year 2012 is the third year without access to the chambers and the Front-End electronics, the fraction of good channels is still very high at 99.1% thanks also to the constant care provided by the on-site operation team. The downtime caused to CMS as a consequence of DT failures is to-date <2%. The intervention on the LV power supplies, which required a large number of CAEN modules (137 A3050, 13 A3100, and 3 MAO) to be removed from the detector, reworked and tested during this Year-End Technical Stop, can now, after a few months of stable operation of the LV, be declared to have solved once-and-for-all the persistent problem with the overheating LV Anderson connectors. Another piece of very good news is that measurements of the noise from single-hit rate outside the drift-time box as a function of the LHC luminosity show that the noise rate and distribution are consistent with expectations of the simulations in the Muon TDR, which have guided the detector design and constru...

  12. The TALE Fluorescence Detectors

    Science.gov (United States)

    Jui, Charles

    2009-05-01

    The TALE fluorescence detectors are designed to extend the threshold for fluorescence observation by TA down to 3x10^16 eV. It will comprise two main components. The first is a set of 24 telescopes working in stereo, with an existing TA FD station at ˜6 km separation. These will cover between 3-31 degrees in elevation and have azimuthal coverage maximizing the stereo aperture in the 10^18-10^19 eV energy range. The second component consists of 15 telescopes equipped with 4m diameter mirrors and covering the sky between 31 and 73 degrees in elevation. The larger mirror size pushes the physics threshold down to 3x10^16 eV, and provides view of the shower maximum for the lower energy events. The Tower detector will cover one quadrant in azimuth and operate in hybrid mode with the TALE infill array to provide redundant composition measurements from both shower maximum information and muon-to-electron ratio.

  13. VNR CMS Pixel detector replacement

    CERN Document Server

    2017-01-01

    Joel Butler, spokesperson of the CMS collaboration explains how a team from many different partner institutes installed a new detector in CMS. This detector is the silicon pixel detector and they’ve been working on it for about five years, to replace one of our existing detectors. This detectors measures particles closer to the beam than any of the other components of this huge detector behind me. It gives us the most precise picture of tracks as they come out of the collisions and expand and travel through the detector. This particular device has twice as many pixels, 120 million, as opposed to about 68 million in the old detector and it can take data faster and pump it out to the analysis more quickly. 00’53’’ Images of the descent, insertion and installation of first piece of the Pixel detector on Tue Feb 28. Images of the descent, insertion and installation of second piece of the Pixel and the two cylinders being joined.

  14. Tomography of Spatial Mode Detectors

    CERN Document Server

    Bobrov, Ivan; Markov, Anton; Straupe, Stanislav; Kulik, Sergey

    2014-01-01

    Transformation and detection of photons in higher-order spatial modes usually requires complicated holographic techniques. Detectors based on spatial holograms suffer from non-idealities and should be carefully calibrated. We report a novel method for analyzing the quality of projective measurements in spatial mode basis inspired by quantum detector tomography. It allows us to calibrate the detector response using only gaussian beams. We experimentally investigate the inherent inaccuracy of the existing methods of mode transformation and provide a full statistical reconstruction of the POVM (positive operator valued measure) elements for holographic spatial mode detectors.

  15. Position-sensitive superconductor detectors

    Science.gov (United States)

    Kurakado, M.; Taniguchi, K.

    2016-12-01

    Superconducting tunnel junction (STJ) detectors and superconducting transition- edge sensors (TESs) are representative superconductor detectors having energy resolutions much higher than those of semiconductor detectors. STJ detectors are thin, thereby making it suitable for detecting low-energy X rays. The signals of STJ detectors are more than 100 times faster than those of TESs. By contrast, TESs are microcalorimeters that measure the radiation energy from the change in the temperature. Therefore, signals are slow and their time constants are typically several hundreds of μs. However, TESs possess excellent energy resolutions. For example, TESs have a resolution of 1.6 eV for 5.9-keV X rays. An array of STJs or TESs can be used as a pixel detector. Superconducting series-junction detectors (SSJDs) comprise multiple STJs and a single-crystal substrate that acts as a radiation absorber. SSJDs are also position sensitive, and their energy resolutions are higher than those of semiconductor detectors. In this paper, we give an overview of position-sensitive superconductor detectors.

  16. PET detector modules based on novel detector technologies

    Energy Technology Data Exchange (ETDEWEB)

    Moses, W.W.; Derenzo, S.E.; Budinger, T.F.

    1994-05-01

    A successful PET detector module must identify 511 keV photons with: high efficiency (>85%), high spatial resolution (<5 mm fwhm), low cost (<$600 / in{sup 2}), low dead time (<4 {mu}s in{sup 2}), good timing resolution (<5 ns fwhm for conventional PET, <200 ps fwhm for time of flight), and good energy resolution (<100 keV fwhm), where these requirements are listed in decreasing order of importance. The ``high efficiency`` requirement also implies that the detector modules must pack together without inactive gaps. Several novel and emerging radiation detector technologies could improve the performance of PET detectors. Avalanche photodiodes, PIN photodiodes, metal channel dynode photomultiplier tubes, and new scintillators all have the potential to improve PET detectors significantly.

  17. High-performance low-noise 128-channel readout-integrated circuit for flat-panel x-ray detector systems

    Science.gov (United States)

    Beuville, Eric J.; Belding, Mark; Costello, Adrienne N.; Hansen, Randy; Petronio, Susan M.

    2004-05-01

    A silicon mixed-signal integrated circuit is needed to extract and process x-ray induced signals from a coated flat panel thin film transistor array (TFT) in order to generate a digital x-ray image. Indigo Systems Corporation has designed, fabricated, and tested such a readout integrated circuit (ROIC), the ISC9717. This off-the-shelf, high performance, low-noise, 128-channel device is fully programmable with a multistage pipelined architecture and a 9 to 14-bit programmable A/D converter per channel, making it suitable for numerous X-ray medical imaging applications. These include high-resolution radiography in single frame mode and fluoroscopy where high frame rates are required. The ISC9717 can be used with various flat panel arrays and solid-state detectors materials: Selenium (Se), Cesium Iodide (CsI), Silicon (Si), Amorphous Silicon, Gallium Arsenide (GaAs), and Cadmium Zinc Telluride (CdZnTe). The 80-micron pitch ROIC is designed to interface (wire bonding or flip-chip) along one or two sides of the x-ray panel, where ROICs are abutted vertically, each reading out charge from pixels multiplexed onto 128 horizontal read lines. The paper will present the design and test results of the ROIC, including the mechanical and electrical interface to a TFT array, system performance requirements, output multiplexing of the digital signals to an off-board processor, and characterization test results from fabricated arrays.

  18. Model-based correction for scatter and tailing effects in simultaneous 99mTc and 123I imaging for a CdZnTe cardiac SPECT camera

    Science.gov (United States)

    Holstensson, M.; Erlandsson, K.; Poludniowski, G.; Ben-Haim, S.; Hutton, B. F.

    2015-04-01

    An advantage of semiconductor-based dedicated cardiac single photon emission computed tomography (SPECT) cameras when compared to conventional Anger cameras is superior energy resolution. This provides the potential for improved separation of the photopeaks in dual radionuclide imaging, such as combined use of 99mTc and 123I . There is, however, the added complexity of tailing effects in the detectors that must be accounted for. In this paper we present a model-based correction algorithm which extracts the useful primary counts of 99mTc and 123I from projection data. Equations describing the in-patient scatter and tailing effects in the detectors are iteratively solved for both radionuclides simultaneously using a maximum a posteriori probability algorithm with one-step-late evaluation. Energy window-dependent parameters for the equations describing in-patient scatter are estimated using Monte Carlo simulations. Parameters for the equations describing tailing effects are estimated using virtually scatter-free experimental measurements on a dedicated cardiac SPECT camera with CdZnTe-detectors. When applied to a phantom study with both 99mTc and 123I, results show that the estimated spatial distribution of events from 99mTc in the 99mTc photopeak energy window is very similar to that measured in a single 99mTc phantom study. The extracted images of primary events display increased cold lesion contrasts for both 99mTc and 123I.

  19. Neutron detector and fabrication method thereof

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, Harish B.; Nagarkar, Vivek V.; Ovechkina, Olena E.

    2016-08-16

    A neutron detector and a method for fabricating a neutron detector. The neutron detector includes a photodetector, and a solid-state scintillator operatively coupled to the photodetector. In one aspect, the method for fabricating a neutron detector includes providing a photodetector, and depositing a solid-state scintillator on the photodetector to form a detector structure.

  20. Particle detector spatial resolution

    Science.gov (United States)

    Perez-Mendez, V.

    1992-12-15

    Method and apparatus for producing separated columns of scintillation layer material, for use in detection of X-rays and high energy charged particles with improved spatial resolution is disclosed. A pattern of ridges or projections is formed on one surface of a substrate layer or in a thin polyimide layer, and the scintillation layer is grown at controlled temperature and growth rate on the ridge-containing material. The scintillation material preferentially forms cylinders or columns, separated by gaps conforming to the pattern of ridges, and these columns direct most of the light produced in the scintillation layer along individual columns for subsequent detection in a photodiode layer. The gaps may be filled with a light-absorbing material to further enhance the spatial resolution of the particle detector. 12 figs.

  1. 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)

  2. Direction sensitive neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Ahlen, Steven; Fisher, Peter; Dujmic, Denis; Wellenstein, Hermann F.; Inglis, Andrew

    2017-01-31

    A neutron detector includes a pressure vessel, an electrically conductive field cage assembly within the pressure vessel and an imaging subsystem. A pressurized gas mixture of CF.sub.4, .sup.3He and .sup.4He at respective partial pressures is used. The field cage establishes a relatively large drift region of low field strength, in which ionization electrons generated by neutron-He interactions are directed toward a substantially smaller amplification region of substantially higher field strength in which the ionization electrons undergo avalanche multiplication resulting in scintillation of the CF.sub.4 along scintillation tracks. The imaging system generates two-dimensional images of the scintillation patterns and employs track-finding to identify tracks and deduce the rate and direction of incident neutrons. One or more photo-multiplier tubes record the time-profile of the scintillation tracks permitting the determination of the third coordinate.

  3. Pixelated gamma detector

    Energy Technology Data Exchange (ETDEWEB)

    Dolinsky, Sergei Ivanovich; Yanoff, Brian David; Guida, Renato; Ivan, Adrian

    2016-12-27

    A pixelated gamma detector includes a scintillator column assembly having scintillator crystals and optical transparent elements alternating along a longitudinal axis, a collimator assembly having longitudinal walls separated by collimator septum, the collimator septum spaced apart to form collimator channels, the scintillator column assembly positioned adjacent to the collimator assembly so that the respective ones of the scintillator crystal are positioned adjacent to respective ones of the collimator channels, the respective ones of the optical transparent element are positioned adjacent to respective ones of the collimator septum, and a first photosensor and a second photosensor, the first and the second photosensor each connected to an opposing end of the scintillator column assembly. A system and a method for inspecting and/or detecting defects in an interior of an object are also disclosed.

  4. Subnanosecond Scintillation Detector

    Science.gov (United States)

    Hoenk, Michael (Inventor); Hennessy, John (Inventor); Hitlin, David (Inventor)

    2017-01-01

    A scintillation detector, including a scintillator that emits scintillation; a semiconductor photodetector having a surface area for receiving the scintillation, wherein the surface area has a passivation layer configured to provide a peak quantum efficiency greater than 40% for a first component of the scintillation, and the semiconductor photodetector has built in gain through avalanche multiplication; a coating on the surface area, wherein the coating acts as a bandpass filter that transmits light within a range of wavelengths corresponding to the first component of the scintillation and suppresses transmission of light with wavelengths outside said range of wavelengths; and wherein the surface area, the passivation layer, and the coating are controlled to increase the temporal resolution of the semiconductor photodetector.

  5. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G. Gomez

    2011-01-01

    A new set of muon alignment constants was approved in August. The relative position between muon chambers is essentially unchanged, indicating good detector stability. The main changes concern the global positioning of the barrel and of the endcap rings to match the new Tracker geometry. Detailed studies of the differences between track-based and optical alignment of DTs have proven to be a valuable tool for constraining Tracker alignment weak modes, and this information is now being used as part of the alignment procedure. In addition to the “split-cosmic” analysis used to investigate the muon momentum resolution at high momentum, a new procedure based on reconstructing the invariant mass of di-muons from boosted Zs is under development. Both procedures show an improvement in the momentum precision of Global Muons with respect to Tracker-only Muons. Recent developments in track-based alignment include a better treatment of the tails of residual distributions and accounting for correla...

  6. Chemical aerosol Raman detector

    Science.gov (United States)

    Aggarwal, R. L.; Farrar, L. W.; Di Cecca, S.; Amin, M.; Perkins, B. G.; Clark, M. L.; Jeys, T. H.; Sickenberger, D. W.; D'Amico, F. M.; Emmons, E. D.; Christesen, S. D.; Kreis, R. J.; Kilper, G. K.

    2017-03-01

    A sensitive chemical aerosol Raman detector (CARD) has been developed for the trace detection and identification of chemical particles in the ambient atmosphere. CARD includes an improved aerosol concentrator with a concentration factor of about 40 and a CCD camera for improved detection sensitivity. Aerosolized isovanillin, which is relatively safe, has been used to characterize the performance of the CARD. The limit of detection (SNR = 10) for isovanillin in 15 s has been determined to be 1.6 pg/cm3, which corresponds to 6.3 × 109 molecules/cm3 or 0.26 ppb. While less sensitive, CARD can also detect gases. This paper provides a more detailed description of the CARD hardware and detection algorithm than has previously been published.

  7. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    Z. Szillasi and G. Gomez.

    2013-01-01

    When CMS is opened up, major components of the Link and Barrel Alignment systems will be removed. This operation, besides allowing for maintenance of the detector underneath, is needed for making interventions that will reinforce the alignment measurements and make the operation of the alignment system more reliable. For that purpose and also for their general maintenance and recalibration, the alignment components will be transferred to the Alignment Lab situated in the ISR area. For the track-based alignment, attention is focused on the determination of systematic uncertainties, which have become dominant, since now there is a large statistics of muon tracks. This will allow for an improved Monte Carlo misalignment scenario and updated alignment position errors, crucial for high-momentum muon analysis such as Z′ searches.

  8. Alpine Pixel Detector Layout

    CERN Document Server

    Delebecque, P; The ATLAS collaboration; Geffroy, N; Massol, N; Rambure, T; Todorov, T

    2013-01-01

    A description of an optimized layout of pixel sensors based on a stave that combines both barrel and endcap module orientations. The mechanical stiffness of the structure is provided by carbon fiber shells spaced by carbon foam. The cooling of the modules is provided by two-phase $CO_{2}$ flowing in a thin titanium pipe glued inside the carbon fiber foam. The electrical services of all modules are provided by a single stave flex. This layout eliminates the need for separate barrel and endcap detector structures, and therefore the barrel services material in front of the endcap. The transition from barrel to endcap module orientation is optimized separately for each layer in order to minimize the active pixel area and the traversed material. The sparse module spacing in the endcap part of the stave allows for multiple fixation points, and for a stiff overall structure composed only of staves interconnected by stiff disks.

  9. The SPICE Detector at ISAC

    Directory of Open Access Journals (Sweden)

    Garnsworthy A.B.

    2013-12-01

    Full Text Available A new ancillary detector system for the TIGRESS HPGe array called SPectrometer for Internal Conversion Electrons (SPICE is currently under development. SPICE consists of a segmented electron detector, photon shield and a permanent magnetic lens. SPICE will enable in-beam electron spectroscopy and, in coupling to the TIGRESS HPGe array, coincident gamma-electron spectroscopy with stable and radioactive beams.

  10. Micro-channel plate detector

    Science.gov (United States)

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  11. Micromegas detector developments for MIMAC

    CERN Document Server

    Ferrer-Ribas, E; Calvet, D; Colas, P; Druillole, F; Giomataris, Y; Iguaz, F J; Mols, J P; Pancin, J; Papaevangelou, T; Billard, J; Bosson, G; Bouly, J L; Bourrion, O; Fourel, Ch; Grignon, C; Guillaudin, O; Mayet, F; Richer, J P; Santos, D; Golabek, C; Lebreton, L

    2011-01-01

    The aim of the MIMAC project is to detect non-baryonic Dark Matter with a directional TPC. The recent Micromegas efforts towards building a large size detector will be described, in particular the characterization measurements of a prototype detector of 10 $\\times$ 10 cm$^2$ with a 2 dimensional readout plane. Track reconstruction with alpha particles will be shown.

  12. ALICE Time Of Flight Detector

    CERN Multimedia

    Alici, A

    2013-01-01

    Charged particles in the intermediate momentum range are identified in ALICE by the Time Of Flight (TOF) detector. The time measurement with the TOF, in conjunction with the momentum and track length measured by the tracking detector, is used to calculate the particle mass.

  13. R& D for Future Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Brau, J.

    2004-12-13

    Research and development of detector technology are critical to the future particle physics program. The goals of the International Linear Collider, in particular, require advances that are challenging, despite the progress driven in recent years by the needs of the Large Hadron Collider. The ILC detector goals and challenges are described and the program to address them is summarized.

  14. Fast Timing for Collider Detectors

    CERN Document Server

    CERN. Geneva

    2017-01-01

    Advancements in fast timing particle detectors have opened up new possibilities to design collider detectors that fully reconstruct and separate event vertices and individual particles in the time domain. The applications of these techniques are considered for the physics at HL-LHC.

  15. Space-based detectors

    Science.gov (United States)

    Sesana, A.; Weber, W. J.; Killow, C. J.; Perreur-Lloyd, M.; Robertson, D. I.; Ward, H.; Fitzsimons, E. D.; Bryant, J.; Cruise, A. M.; Dixon, G.; Hoyland, D.; Smith, D.; Bogenstahl, J.; McNamara, P. W.; Gerndt, R.; Flatscher, R.; Hechenblaikner, G.; Hewitson, M.; Gerberding, O.; Barke, S.; Brause, N.; Bykov, I.; Danzmann, K.; Enggaard, A.; Gianolio, A.; Vendt Hansen, T.; Heinzel, G.; Hornstrup, A.; Jennrich, O.; Kullmann, J.; Møller-Pedersen, S.; Rasmussen, T.; Reiche, J.; Sodnik, Z.; Suess, M.; Armano, M.; Sumner, T.; Bender, P. L.; Akutsu, T.; Sathyaprakash, B. S.

    2014-12-01

    The parallel session C5 on Space-Based Detectors gave a broad overview over the planned space missions related to gravitational wave detection. Overviews of the revolutionary science to be expected from LISA was given by Alberto Sesana and Sasha Buchman. The launch of LISA Pathfinder (LPF) is planned for 2015. This mission and its payload "LISA Technology Package" will demonstrate key technologies for LISA. In this context, reference masses in free fall for LISA, and gravitational physics in general, was described by William Weber, laser interferometry at the pico-metre level and the optical bench of LPF was presented by Christian Killow and the performance of the LPF optical metrology system by Paul McNamara. While LPF will not yet be sensitive to gravitational waves, it may nevertheless be used to explore fundamental physics questions, which was discussed by Michele Armano. Some parts of the LISA technology that are not going to be demonstrated by LPF, but under intensive development at the moment, were presented by Oliver Jennrich and Oliver Gerberding. Looking into the future, Japan is studying the design of a mid-frequency detector called DECIGO, which was discussed by Tomotada Akutsu. Using atom interferometry for gravitational wave detection has also been recently proposed, and it was critically reviewed by Peter Bender. In the nearer future, the launch of GRACE Follow-On (for Earth gravity observation) is scheduled for 2017, and it will include a Laser Ranging Interferometer as technology demonstrator. This will be the first inter-spacecraft laser interferometer and has many aspects in common with the LISA long arm, as discussed by Andrew Sutton.

  16. ENSTAR detector for -mesic studies

    Indian Academy of Sciences (India)

    A Chatterjee; B J Roy; V Jha; P Shukla; H Machnder; GEM Collaboration

    2006-05-01

    We have initiated a search for a new type of nuclear matter, the -mesic nucleus, using beams from the multi-GeV hadron facility, COSY at Juelich, Germany. A large acceptance scintillator detector, ENSTAR has been designed and built at BARC, Mumbai and fully assembled and tested at COSY. A test run for calibration and evaluation has been completed. In this contribution we present the design and technical details of the ENSTAR detector and how it will be used to detect protons and pions (the decay products of -mesic bound state). The detector is made of plastic scintillators arranged in three concentric cylindrical layers. The readout of the detectors is by means of optical fibres. The layers are used to generate - spectra for particle identification and total energy information of stopped particles. The granularity of the detector allows for position ( and ) determination making the event reconstruction kinematically complete.

  17. Recent detector developments at SINTEF (industrial presentation)

    Science.gov (United States)

    Sundby Avset, Berit; Evensen, Lars; Uri Jensen, Geir; Mo, Sjur; Kari Schjølberg-Henriksen; Westgaard, Trond

    1998-02-01

    Results from SINTEF's research on radiation hardness of silicon detectors, thin silicon detectors, silicon drift devices, reach-through avalanche photodiodes, and detectors with thin dead layers are presented.

  18. The 150 ns detector project: Progress with small detectors

    Science.gov (United States)

    Warburton, W. K.; Russell, S. R.; Kleinfelder, Stuart A.; Segal, Julie

    1994-09-01

    This project's long term goal is to develop a pixel area detector capable of 6 MHz frame rates (150 ns/frame). Our milestones toward this goal are: a single pixel, 1 × 256 1D and 8 × 8 2D detectors, 256 × 256 2D detectors and, finally, 1024 × 1024 2D detectors. The design strategy is to supply a complete electronics chain (resetting preamp, selectable gain amplifier, analog-to-digital converter (ADC), and memory) for each pixel. In the final detectors these will all be custom integrated circuits. The front end preamplifiers are being integrated first, since their design and performance are both the most unusual and also critical to the project's success. Similarly, our early work is also concentrating on devising and perfecting detector structures which are thick enough (1 mm) to absorb over 99% of the incident X-rays in the energy range of interest. In this paper we discuss our progress toward the 1 × 256 1D and 8 × 8 2D detectors. We have fabricated sample detectors at Stanford's Center for Integrated Systems and are preparing both to test them individually and to wirebond them to the preamplifier samples to produce our first working small 1D and 2D detectors. We will describe our solutions to the design problems associated with collecting charge in less than 30 ns from 1 mm thick pixels in high resistivity silicon. We have constructed and tested the front end of our preamplifier design using a commercial 1.2 μm CMOS technology and are moving on to produce a few channels of the complete preamplifier, including a switchable gain stage and output stage. We will discuss both the preamplifier design and our initial test results.

  19. Acquisition System and Detector Interface for Power Pulsed Detectors

    Science.gov (United States)

    Cornat, Rémi; CALICE Colaboration

    A common DAQ system is being developed within the CALICE collaboration. It provides a flexible and scalable architecture based on giga-ethernet and 8b/10b serial links in order to transmit either slow control data, fast signals or read out data. A detector interface (DIF) is used to connect detectors to the DAQ system based on a single firmware shared among the collaboration but targeted on various physical implementations. The DIF allows to build, store and queue packets of data as well as to control the detectors providing USB and serial link connectivity. The overall architecture is foreseen to manage several hundreds of thousands channels.

  20. Acquisition System and Detector Interface for Power Pulsed Detectors

    CERN Document Server

    Cornat, R

    2012-01-01

    A common DAQ system is being developed within the CALICE collaboration. It provides a flexible and scalable architecture based on giga-ethernet and 8b/10b serial links in order to transmit either slow control data, fast signals or read out data. A detector interface (DIF) is used to connect detectors to the DAQ system based on a single firmware shared among the collaboration but targeted on various physical implementations. The DIF allows to build, store and queue packets of data as well as to control the detectors providing USB and serial link connectivity. The overall architecture is foreseen to manage several hundreds of thousands channels.

  1. Detector instrumentation for nuclear fission studies

    Indian Academy of Sciences (India)

    Akhil Jhingan

    2015-09-01

    The study of heavy-ion-induced fusion–fission reactions require nuclear instrumentation that include particle detectors such as proportional counters, ionization chambers, silicon detectors, scintillation detectors, etc., and the front-end electronics for these detectors. Using the detectors mentioned above, experimental facilities have been developed for carrying out fusion–fission experiments. This paper reviews the development of detector instrumentation at IUAC.

  2. Making MUSIC: A multiple sampling ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Shumard, B. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)]. E-mail: shumard@phy.anl.gov; Henderson, D.J. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Rehm, K.E. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Tang, X.D. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)

    2007-08-15

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the ({alpha}, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for ({alpha}, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only ({alpha}, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the ({alpha}, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the ({alpha}, p) reaction to reach the anode segment below the reaction.

  3. Plastic neutron detectors.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Tiffany M.S; King, Michael J.; Doty, F. Patrick

    2008-12-01

    This work demonstrated the feasibility and limitations of semiconducting {pi}-conjugated organic polymers for fast neutron detection via n-p elastic scattering. Charge collection in conjugated polymers in the family of substituted poly(p-phenylene vinylene)s (PPV) was evaluated using band-edge laser and proton beam ionization. These semiconducting materials can have high H/C ratio, wide bandgap, high resistivity and high dielectric strength, allowing high field operation with low leakage current and capacitance noise. The materials can also be solution cast, allowing possible low-cost radiation detector fabrication and scale-up. However, improvements in charge collection efficiency are necessary in order to achieve single particle detection with a reasonable sensitivity. The work examined processing variables, additives and environmental effects. Proton beam exposure was used to verify particle sensitivity and radiation hardness to a total exposure of approximately 1 MRAD. Conductivity exhibited sensitivity to temperature and humidity. The effects of molecular ordering were investigated in stretched films, and FTIR was used to quantify the order in films using the Hermans orientation function. The photoconductive response approximately doubled for stretch-aligned films with the stretch direction parallel to the electric field direction, when compared to as-cast films. The response was decreased when the stretch direction was orthogonal to the electric field. Stretch-aligned films also exhibited a significant sensitivity to the polarization of the laser excitation, whereas drop-cast films showed none, indicating improved mobility along the backbone, but poor {pi}-overlap in the orthogonal direction. Drop-cast composites of PPV with substituted fullerenes showed approximately a two order of magnitude increase in photoresponse, nearly independent of nanoparticle concentration. Interestingly, stretch-aligned composite films showed a substantial decrease in

  4. ATLAS Forward Detectors and Physics

    CERN Document Server

    Soni, N

    2010-01-01

    In this communication I describe the ATLAS forward physics program and the detectors, LUCID, ZDC and ALFA that have been designed to meet this experimental challenge. In addition to their primary role in the determination of ATLAS luminosity these detectors - in conjunction with the main ATLAS detector - will be used to study soft QCD and diffractive physics in the initial low luminosity phase of ATLAS running. Finally, I will briefly describe the ATLAS Forward Proton (AFP) project that currently represents the future of the ATLAS forward physics program.

  5. Detector for a linear collider

    CERN Document Server

    Mnich, J

    2003-01-01

    The proposals under discussion for a new e^{+}e^{-} linear collider with centre-of-mass energies around 1 TeV include designs for large detectors with unprecedented performances in energy, momentum and position resolution. These very stringent requirements are dictated by the precision measurements aimed at this collider to complement the exploratory experiments at the Large Hadron Collider. Here a status report on detector R&D projects for the liner collider is given focused on the technologies under study for the vertex detector, the large tracking chamber and the calorimeters.

  6. Requirements on high resolution detectors

    Energy Technology Data Exchange (ETDEWEB)

    Koch, A. [European Synchrotron Radiation Facility, Grenoble (France)

    1997-02-01

    For a number of microtomography applications X-ray detectors with a spatial resolution of 1 {mu}m are required. This high spatial resolution will influence and degrade other parameters of secondary importance like detective quantum efficiency (DQE), dynamic range, linearity and frame rate. This note summarizes the most important arguments, for and against those detector systems which could be considered. This article discusses the mutual dependencies between the various figures which characterize a detector, and tries to give some ideas on how to proceed in order to improve present technology.

  7. CLIC Detector and Physics Status

    CERN Document Server

    AUTHOR|(SzGeCERN)627941

    2017-01-01

    This contribution to LCWS2016 presents recent developments within the CLICdp collaboration. An updated scenario for the staged operation of CLIC has been published; the accelerator will operate at 380 GeV, 1.5 TeV and 3 TeV. The lowest energy stage is optimised for precision Higgs and top physics, while the higher energy stages offer extended Higgs and BSM physics sensitivity. The detector models CLIC_SiD and CLIC_ILD have been replaced by a single optimised detector; CLICdet. Performance studies and R&D in technologies to meet the requirements for this detector design are ongoing.

  8. A computerized track detector reader

    Energy Technology Data Exchange (ETDEWEB)

    Rosinski, S.W. (Centralne Lab. Ochrony Radiologicznej, Warsaw (Poland))

    1993-01-01

    The structure and basic operation function of a computerized facility named Track Detection Reader is described. This facility is used for recording, counting and evaluation of defects made by [alpha]-particles in a solid state detector. It consists of a microscope equipped with the movable stage, a TV screen and PC-AT computer. The microscope stage is being controlled by a stepper motor. The TV screen enables surface visualization of the detector analyzed while the PC-AT computer is being used for digital analysis of the detector surface, according to the functions of the program. (author). 4 refs, 3 figs.

  9. The CDF Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Tkaczyk, S.; Carter, H.; Flaugher, B. [and others

    1993-09-01

    A silicon strip vertex detector was designed, constructed and commissioned at the CDF experiment at the Tevatron collider at Fermilab. The mechanical design of the detector, its cooling and monitoring are presented. The front end electronics employing a custom VLSI chip, the readout electronics and various components of the SVX system are described. The system performance and the experience with the operation of the detector in the radiation environment are discussed. The device has been taking colliding beams data since May of 1992, performing at its best design specifications and enhancing the physics program of CDF.

  10. Thermoluminescent Detectors in Mixed Fields

    CERN Document Server

    Mala, P; Biskup, B; Roeed, K

    2012-01-01

    This note reports on using of thermoluminescent detectors for radiation monitoring in the LHC tunnel and in the shielded areas around the tunnel. The accumulated annual doses in these areas vary a lot so a dosimeter used there should cover a large dose range. TL detectors can measure dose from 0.1 mGy to few kGy (with a recently proposed new technique which needs more studies up to 1 MGy). This report presents studies of these detectors in mixed fields similar to radiation field in the LHC and the possible usage of their results for calculation of high energy hadron and thermal neutron fluence.

  11. MUON DETECTORS: DT

    CERN Multimedia

    M. Dallavalle

    In the past months, the DT electronics has run in a stable and reliable way, demonstrated again through the CRAFT exercise. Operation when the CMS magnetic field was on has been satisfactory. The detector safety control and monitoring is improving constantly as the DT group accumulates running experience. The DT DAQ and DCS systems proved very stable during the intensive CRAFT period. The few issues that were identified by the DCS and on-line monitoring did not prevent the run to continue, so that the record of the DT in the data taking efficiency was very good. The long running period was also used to continue the transition from a system run by experts to one run by shifters, which was in the large part successful. Improvements, mostly in consolidation of error reporting, were identified and will be addressed in the coming shut-down. During the CRAFT data taking, DT triggered about 300 million cosmics with the magnet at 3.8T and the silicon strip tracker in the readout. Although a dedicated configuratio...

  12. MUON DETECTORS: CSC

    CERN Multimedia

    J. Hauser

    2011-01-01

    The CSC detector continued to operate well during the March-June 2011 period. As the luminosity has climbed three orders of magnitude, the currents drawn in the CSC high-voltage system have risen correspondingly, and the current trip thresholds have been increased from 1 μA to 5 μA (and 20 in ME1/1 chambers). A possible concern is that a long-lasting and undesirable corona is capable of drawing about 1 μA, and thus may not be detected by causing current trips; on the other hand it is easily dealt with by cycling HV when detected. To better handle coronas, software is being developed to better detect them, although a stumbling block is the instability of current measurements in some of the channels of the CAEN supplies used in ME1/1. A survey of other issues faced by the CSC Operations team was discussed at the 8th June 2011 CSC Operations/DPG meeting (Rakness). The most important issues, i.e. those that have caused a modest amount of downtime, are all being actively addressed. These are:...

  13. ATLAS Detector Upgrade Prospects

    CERN Document Server

    Dobre, Monica; The ATLAS collaboration

    2016-01-01

    After the successful operation at the centre-of-mass energies of 7 and 8 TeV in 2010-2012, the LHC is ramped up and successfully took data at the centre-of-mass energies of 13 TeV in 2015. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, delivering of the order of five times the LHC nominal instantaneous luminosity along with luminosity levelling. The ultimate goal is to extend the dataset from about few hundred f b −1 expected for LHC running to 3000 f b −1 by around 2035 for ATLAS and CMS. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tracker, significant upgrades of the calorimeter and muon systems, as well as improved triggers and data acquisition. ATLAS is also examining potential benefits of ext...

  14. MUON DETECTORS: RPC

    CERN Multimedia

    Pierluigi Paolucci

    2013-01-01

    In the second part of 2013 the two main activities of the RPC project are the reparation and maintenance of the present system and the construction and installation of the RE4 system. Since the opening of the barrel, repair activities on the gas, high-voltage and electronic systems are being done in parallel, in agreement with the CMS schedule. In YB0, the maintenance of the RPC detector was in the shadow of other interventions, nevertheless the scaffolding turned out to be a good solution for our gas leaks searches. Here we found eight leaking channels for about 100 l/h in total. 10 RPC/DT modules were partially extracted –– 90 cm –– in YB0, YB–1 and YB–2 to allow for the replacement of FE and LV distribution boards. Intervention was conducted on an additional two chambers on the positive endcap to solve LV and threshold control problems. Until now we were able to recover 0.67% of the total number of RPC electronic channels (1.5% of the channels...

  15. MUON DETECTORS: DT

    CERN Multimedia

    I. Redondo Fernandez

    2011-01-01

    The DT system has operated successfully during the entire 2011 data-taking: the fraction of good channels was always >99.4 % and the downtime caused to CMS amounts to a few inverse picobarns. This excellent performance does not come without a price: the DT group requested more than 30 short accesses to the underground experimental cavern (UXC).  A large fraction of interventions was for dealing with overheated LV Anderson connectors, whose failure can affect larger sections of the detector (a whole chamber, or half a wheel of the CMS barrel, etc.). A crash programme for reworking those connections will take place during the Year-End Technical Stop. The system of six vd chambers (VDC) that were installed on the DT exhaust gas line have operated successfully. The VDCs are small drift chambers the size of a shoebox that measure the drift velocity every 10 minutes. Possible deviations from the nominal value could be caused by a contamination of the gas mixture or changes in pressure or temperat...

  16. MUON DETECTORS: DT

    CERN Multimedia

    R.Carlin

    2010-01-01

    DT operation during 2010 LHC collisions, both in proton-proton and heavy ions, has been outstanding. The DT downtime has been below 0.1% throughout the whole year, mainly caused by the manual Resync commands that took around a minute for being processed. An automatic resynchronisation procedure has been enabled by August 27 and since then the downtime has been negligible (though constantly monitored). The need for these Resync commands is related to sporadic noise events that occasionally fill the RO buffers or unlock the readout links. Their rate is low, in the order of a few per week. Besides that, only one pp collisions run (1 hour 30 minutes run) has been marked as bad for DT, because of an incident with a temperature sensor that triggered a false alarm and powered off one wheel. Nevertheless, quite a large number of interventions (>30) have been made in the cavern during the year, in order to keep such a large fraction of the detector operational. Most of those are due to the overheating of the ...

  17. MUON DETECTORS: DT

    CERN Multimedia

    I. Redondo

    2011-01-01

    During the second quarter of 2011, the DT system has continued to operate successfully with a high fraction of good channels (>99 %) and causing extremely little downtime to CMS. The high fraction of operated channels did not come for free: DT requested 18 short UXC accesses in the 3 months from March to May 2011. The dominant causes for these interventions were HV related interventions (7), which typically affect a small fraction of a chamber, and interventions for dealing with overheated LV Anderson connectors (7), whose failure could affect larger fractions of the detector (a whole chamber, half a wheel). With respect to the CMS downtime, a successful effort with colleagues from the DT Track Finder of the Level-1 Trigger system allowed to overcome a relatively relevant source of downtime from DTTF FED Out-Of-Sync errors, which would appear randomly during data-taking. The DT group developed a system configuration that would make it possible to reproduce the error without beam, thereby sparing lumin...

  18. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    S. Szillasi

    2013-01-01

    The CMS detector has been gradually opened and whenever a wheel became exposed the first operation was the removal of the MABs, the sensor structures of the Hardware Barrel Alignment System. By the last days of June all 36 MABs have arrived at the Alignment Lab at the ISR where, as part of the Alignment Upgrade Project, they are refurbished with new Survey target holders. Their electronic checkout is on the way and finally they will be recalibrated. During LS1 the alignment system will be upgraded in order to allow more precise reconstruction of the MB4 chambers in Sector 10 and Sector 4. This requires new sensor components, so called MiniMABs (pictured below), that have already been assembled and calibrated. Image 6: Calibrated MiniMABs are ready for installation For the track-based alignment, the systematic uncertainties of the algorithm are under scrutiny: this study will enable the production of an improved Monte Carlo misalignment scenario and to update alignment position errors eventually, crucial...

  19. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli

    The RPC group has invested a large effort in the study of trigger spikes observed during CRAFT data taking. The chambers are susceptible to noise generated by the flickering of fluorescent and projector lamps in the cavern (with magnetic field on). Soon after the end of CRAFT, it was possible to reproduce the phenomena using a waveform generator and to study possible modifications to be implemented in the grounding schema. Hardware actions have been already taken in order to reduce the detector sensitivity: star washers on the chamber front panels and additional shielding have been added where possible. During the shutdown maintenance activity many different problems were tackled on the barrel part. A few faulty high voltage connector/cable problems were fixed; now only two RPC chambers are left with single-gap mode operation. One chamber in YB+2 was replaced due to gas leakage. All the front-end electronic boards were replaced in 3 chambers (stations MB2 and MB3 in YB-2), that had been damaged after the coo...

  20. Hybrid Superconducting Neutron Detectors

    CERN Document Server

    Merlo, V; Cirillo, M; Lucci, M; Ottaviani, I; Scherillo, A; Celentano, G; Pietropaolo, A

    2014-01-01

    A new neutron detection concept is presented that is based on superconductive niobium (Nb) strips coated by a boron (B) layer. The working principle of the detector relies on the nuclear reaction 10B+n $\\rightarrow$ $\\alpha$+ 7Li , with $\\alpha$ and Li ions generating a hot spot on the current-biased Nb strip which in turn induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T = 8 K and current-biased below the critical current Ic, are driven into the normal state upon thermal neutron irradiation. As a result of the transition, voltage pulses in excess of 40 mV are measured while the bias current can be properly modulated to bring the strip back to the supercond...

  1. MUON DETECTORS: CSC

    CERN Multimedia

    R. Breedon

    Figure 2: Five ME4/2 chambers mounted on the +endcap. At the end of June, five large, outer cathode strip chambers (CSC) that were produced as spares during the original production were mounted on part of the disk space reserved for ME4/2 on the positive endcap (Fig. 2). The chambers were cabled, attached to services, and fully integrated and commissioned into the CSC DAQ and trigger systems. Comprising almost a full trigger sector, CMS will be able to test the significant improvement the trigger efficiency of the EMU system that the presence of the full ME4/2 ring is expected to bring. The return of beam in November was observed as “splash” events in the CSCs in which the detectors were showered with a huge number of particles at the same time. Although the CSCs were operating at a lower standby voltage the multiple hits on a strips could not be individually distinguished.&am...

  2. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2012-01-01

      2011 data-taking was very satisfactory for both the RPC detector and trigger. The RPC system ran very smoothly in 2011, showing an excellent stability and very high data-tacking efficiency. Data loss for RPC was about 0.37%, corresponding to 19 pb−1. Most of the performance studies, based on 2011 data, are now completed and the results have been already approved by CMS to be presented at the RPC 2012 conference (February 2012 at LNF). During 2011, the number of disconnected chambers increased from six to eight corresponding to 0.8% of the full system, while the single-gap-mode chambers increased from 28 to 31. Most of the problematic chambers are due to bad high-voltage connection and electronic failures that can be solved only during the 2013-2014 Long Shutdown. 98.4% of the electronic channels were operational. The average detection efficiency in 2011 was about 95%, which was the same value measured during the HV scan done at the beginning of the 2011 data-taking. Efficiency has be...

  3. MUON DETECTORS: DT

    CERN Multimedia

    M. Dallavalle

    2013-01-01

    The DT collaboration is undertaking substantial work both for detector maintenance – after three years since the last access to the chambers and their front-end electronics – and upgrade. The most critical maintenance interventions are chambers and Minicrate repairs, which have not begun yet, because they need proper access to each wheel of the CMS barrel, meaning space for handling the big chambers in the few cases where they have to be extracted, and, more in general, free access from cables and thermal shields in the front and back side of the chambers. These interventions are planned for between the coming Autumn until next spring. Meanwhile, many other activities are happening, like the “pigtail” intervention on the CAEN AC/DC converters which has just taken place. The upgrade activities continue to evolve in good accordance with the schedule, both for the theta Trigger Board (TTRB) replacement and for the Sector Collector (SC) relocation from the UXC to the US...

  4. Commissioning a Hodoscope Detector

    Science.gov (United States)

    Lulis, Andrew; Merhi, Abdul; Frank, Nathan; Bazin, Daniel; Smith, Jenna; Thoennessen, Michael; MoNA Collaboration

    2013-10-01

    Experiments on neutron-rich nuclei are interesting since they test the limits of current nuclear theory. One method to populate neutron-rich nuclei is to utilize the (d,p) reaction in which the beam nucleus picks up a neutron from the target. This heavier nucleus immediately emits a neutron resulting in the same nucleus as the beam but with lower energy. One challenge is to discriminate decay products from unreacted beam particles by their difference in energy. A hodoscope was recently installed at the National Superconducting Cyclotron Laboratory (NSCL) as part of the MoNA-LISA-Sweeper setup to make experiments using a (d,p) reaction possible. The hodoscope is a 5 × 5 scintillator array consisting of CsI(Na) crystals with a resolution of better than 1%. This presentation will describe the recently commissioned detector and the results of the first data analysis using this device. Work supported by Augustana College and the National Science Foundation grant #0969173.

  5. MUON DETECTORS: RPC

    CERN Multimedia

    G. Pugliese

    2010-01-01

    In the second half of 2010 run, the overall behavior of the RPC system has been very satisfactory, both in terms of detector and trigger performance. This result was achieved through interventions by skilled personnel and fine-tuned analysis procedures. The hardware was quite stable: both gas and power systems did not present significant problems during the data-taking period, confirming the high reliability achieved. Only few interventions on some HV or LV channels were necessary during the periodical technical accesses. The overall result is given by the stable percentage of active channels at about 98.5%. The single exception was at beginning of the ion collisions, when it dipped to 97.4% because of the failure of one LV module, although this was recovered after a few days. The control and monitoring software is now more robust and efficient, providing prompt diagnostics on the status of the entire system. Significant efforts were made in collaboration with the CMS cooling team to secure proper working ...

  6. Transmission diamond imaging detector

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, John, E-mail: smedley@bnl.gov; Pinelli, Don; Gaoweia, Mengjia [Brookhaven National Laboratory, Upton, NY (United States); Muller, Erik; Ding, Wenxiang; Zhou, Tianyi [Stony Brook University, Stony Brook, NY (United States); Bohon, Jen [Case Center for Synchrotron Biosciences, Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH (United States)

    2016-07-27

    Many modern synchrotron techniques are trending toward use of high flux beams and/or beams which require enhanced stability and precise understanding of beam position and intensity from the front end of the beamline all the way to the sample. For high flux beams, major challenges include heat load management in optics (including the vacuum windows) and a mechanism of real-time volumetric measurement of beam properties such as flux, position, and morphology. For beam stability in these environments, feedback from such measurements directly to control systems for optical elements or to sample positioning stages would be invaluable. To address these challenges, we are developing diamond-based instrumented vacuum windows with integrated volumetric x-ray intensity, beam profile and beam-position monitoring capabilities. A 50 µm thick single crystal diamond has been lithographically patterned to produce 60 µm pixels, creating a >1kilopixel free-standing transmission imaging detector. This device, coupled with a custom, FPGA-based readout, has been used to image both white and monochromatic x-ray beams and capture the last x-ray photons at the National Synchrotron Light Source (NSLS). This technology will form the basis for the instrumented end-station window of the x-ray footprinting beamline (XFP) at NSLS-II.

  7. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli

    2010-01-01

    During the technical stop, the RPC team was part of the CMS task force team working on bushing replacements in the Endcap cooling system, also validating the repairs in terms of connectivity (HV, LV and signal cables), and gas leak, on RE chambers. In parallel, the RPC team profited from the opportunity to cure several known problems: six chambers with HV problems (1 off + 5 single gaps) were recovered on both gaps; four known HV problems were localized at chamber level; additional temperature sensors were installed on cooling pipes on negative REs; one broken LV module in RE-1 was replaced. During the last month, the RPC group has made big improvements in the operations tools. New trigger supervisor software has substantially reduced the configuration time. Monitoring is now more robust and more efficient in providing prompt diagnostics. The detector has been under central DCS control for two weeks. Improvements have been made to both functionality and documentation and no major problems were found. Beam s...

  8. MUON DETECTORS: DT

    CERN Multimedia

    C. Fernandez Bedova and M. Dallavalle

    2010-01-01

    After successful operation during the 2009 LHC run, a number of fixes and improvements were carried out on the DT system the winter shutdown. The main concern was related with the impact of the extensive water leak that happened in October in YE+1. Opening of CMS end-caps allowed the DT crew to check if any Minicrates (containing the first level of readout and trigger electronics) in YB+2 and YB-2 were flooded with water. The affected region from top sectors in YB+2 reaches down to the bottom sectors in YB-2 following the water path in the barrel from end to end. No evidence of water penetration was observed, though the passage of water left oxidation and white streaks on the iron and components. In particular, large signs of oxidation have been seen on the YB-2 MB1 top and bottom stations. Review of the impact in YB+1 remains for future openings of CMS wheels, and at present, effort is focused on setting up the water leak detection system in the detector. Another important issue during this shutd...

  9. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2013-01-01

    During LS1, the Resistive Plate Chamber (RPC) collaboration is focusing its efforts on installation and commissioning of the fourth endcap station (RE4) and on the reparation and maintenance of the present system (1100 detectors). The 600 bakelite gaps, needed to build 200 double-gap RE4 chambers are being produced in Korea. Chamber construction and testing sites are located at CERN, in Ghent University, and at BARC (India). At present, 42 chambers have been assembled, 32 chambers have been successfully tested with cosmic rays runs and 7 Super Modules, made by two chambers, have been built at CERN by a Bulgarian/Georgian/Italian team and are now ready to be installed in the positive endcap. The 36 Super Modules needed to complete the positive endcap will be ready in September and installation is scheduled for October 2013. The Link-Board system for RE4 is under construction in Naples. Half of the system has been delivered at CERN in June. Six crates (Link-Board Boxes) and 75 boards, needed to instrument t...

  10. MUON DETECTORS: DT

    CERN Multimedia

    C. Fernandez Bedoya

    2012-01-01

      The major activity of the DT group during this Year-End Technical Stop has been the reworking of LV modules. It has been a large campaign, carefully planned, to try to solve, once and for all, the long-standing problem of Anderson Power connectors overheating. The solution involved removing the 140 CAEN modules from the detector (6.5 kg each), soldering of “pigtails” in a temporary workshop in USC, and thorough testing of all the modules in a local system installed in USC. The operation has been satisfactorily smooth, taking into account the magnitude of the intervention. The system is now back in good shape and ready for commissioning. In addition, HV boards have been cleaned up, HV USC racks have been equipped with water detection cables, and the gas and HV have been switched back on smoothly. Other significant activities have also taken place during this YETS, such as the installation of a new and faster board for the Minicrates secondary link and the migration to Scienti...

  11. ATLAS Detector Upgrade Prospects

    CERN Document Server

    Dobre, Monica; The ATLAS collaboration

    2016-01-01

    After the successful operation at the center-of-mass energies of 7 and 8 TeV in 2010 - 2012, the LHC is ramped up and successfully took data at the center-of-mass energies of 13 TeV in 2015. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, delivering of the order of five times the LHC nominal instantaneous luminosity along with luminosity leveling. The ultimate goal is to extend the dataset from about few hundred fb−1 expected for LHC running to 3000 fb−1 by around 2035 for ATLAS and CMS. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tracker, significant upgrades of the calorimeter and muon systems, as well as improved triggers and data acquisition. ATLAS is also examining potential benefits of extens...

  12. A Rapid Coliform Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC, in collaboration with Lucigen, proposes a rapid genetic detector for spaceflight water systems to enable real-time detection of E-coli with minimal...

  13. Detector Fundamentals for Reachback Analysts

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-03

    This presentation is a part of the DHS LSS spectroscopy course and provides an overview of the following concepts: detector system components, intrinsic and absolute efficiency, resolution and linearity, and operational issues and limits.

  14. Rapid Multiplex Microbial Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC, in collaboration with Lucigen, proposes a rapid nucleic acid-based detector for spaceflight water systems to enable simultaneous quantification of multiple...

  15. Belle II Silicon Vertex Detector

    CERN Document Server

    Mohanty, Gagan B

    2015-01-01

    The Belle II experiment at the SuperKEKB collider in Japan is designed to indirectly probe new physics using approximately 50 times the data recorded by its predecessor. An accurate determination of the decay-point position of subatomic particles such as beauty and charm hadrons as well as a precise measurement of low-momentum charged particles will play a key role in this pursuit. These will be accomplished by a vertex detector, which comprises two layers of pixelated silicon detector and four layers of silicon vertex detector. We describe herein the design, prototyping and construction efforts of the Belle-II silicon vertex detector that is aimed to be commissioned towards the middle of 2017.

  16. GEM Detector Electric Field Simulation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    GEM (Gas Electron Multiplier) detectors have been widely employed in the experimental field of high energy physics and nuclear physics. As a successor to drift chambers, GEMs are much easier to fabricate and have a much higher spatial resolution

  17. Silicon Drift Detectors for ALICE

    CERN Document Server

    Navach, F; CERN. Geneva

    1992-01-01

    The Silicon Drift Detector (SDD) is a semiconductor, not yet extensively used in HEP experiment, which has an excellent spatial resolution and granularity about comparable to a pixel device requiring a number of readout channels two order of magnitude less.

  18. Detector Description Framework in LHCb

    CERN Document Server

    Ponce, Sébastien

    2003-01-01

    The Gaudi architecture and framework are designed to provide a common infrastructure and environment for simulation, filtering, reconstruction and analysis applications. In this context, a Detector Description Service was developed in LHCb in order to also provide easy and coherent access to the description of the experimental apparatus. This service centralizes every information about the detector, including geometry, materials, alignment, calibration, structure and controls. From the proof of concept given by the first functional implementation of this service late 2000, the Detector Description Service has grown and has become one of the major components of the LHCb software, shared among all applications, including simulation, reconstruction, analysis and visualization. We describe here the full and functional implementation of the service. We stress the easiness of customization and extension of the detector description by the user, on the seamless integration with condition databases in order to handle ...

  19. 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.

  20. Microscopic Simulation of Particle Detectors

    CERN Document Server

    Schindler, Heinrich

    Detailed computer simulations are indispensable tools for the development and optimization of modern particle detectors. The interaction of particles with the sensitive medium, giving rise to ionization or excitation of atoms, is stochastic by its nature. The transport of the resulting photons and charge carriers, which eventually generate the observed signal, is also subject to statistical fluctuations. Together with the readout electronics, these processes - which are ultimately governed by the atomic cross-sections for the respective interactions - pose a fundamental limit to the achievable detector performance. Conventional methods for calculating electron drift lines based on macroscopic transport coefficients used to provide an adequate description for traditional gas-based particle detectors such as wire chambers. However, they are not suitable for small-scale devices such as micropattern gas detectors, which have significantly gained importance in recent years. In this thesis, a novel approach, bas...

  1. Nanopillar Optical Antenna Avalanche Detectors

    Science.gov (United States)

    2014-08-30

    68 , (11), 10. 51. Adachi, S., Properties of aluminium gallium ...bandwidth products > 100 GHz. 2 UNIVERSITY OF CALIFORNIA Los Angeles Nanopillar Optical Antenna Avalanche Detectors A dissertation... products > 100 GHz. 6 iii The dissertation of Pradeep

  2. A Classification Leveraged Object Detector

    OpenAIRE

    Sun, Miao; Han, Tony X.; He, Zhihai

    2016-01-01

    Currently, the state-of-the-art image classification algorithms outperform the best available object detector by a big margin in terms of average precision. We, therefore, propose a simple yet principled approach that allows us to leverage object detection through image classification on supporting regions specified by a preliminary object detector. Using a simple bag-of- words model based image classification algorithm, we leveraged the performance of the deformable model objector from 35.9%...

  3. Surface events in HPGe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Abt, Iris; Dinter, Sabine; Faulstich, Florian; Majorovits, Bela; Stelzer, Franz [Max-Planck-Institut fuer Physik, Munich (Germany)

    2011-07-01

    Events on or close to the surface of high purity germanium, HPGe, detectors can introduce backgrounds in low background applications of such devices. The Galatea test-stand, especially developed and constructed at the MPI fuer Physik allows an almost full surface scan of a detector with alpha and beta sources. Events induced by alpha and beta particles can be characterized and surface effects can be studied. First comparisons between data and Monte Carlo are presented.

  4. Repeatability of Harris Corner Detector

    Institute of Scientific and Technical Information of China (English)

    HU Lili

    2003-01-01

    Interest point detectors are commonly employed to reduce the amount of data to be processed. The ideal interest point detector would robustly select those features which are most appropriate or salient for the application and data at hand. This paper shows that interest points are geometrically stable under different transformations.This property makes interest points very successful in the context of image matching. To measure this property quantatively, we introduce a evaluation criterion: repeatability rate.

  5. Electronic detectors for electron microscopy.

    Science.gov (United States)

    Faruqi, A R; McMullan, G

    2011-08-01

    Electron microscopy (EM) is an important tool for high-resolution structure determination in applications ranging from condensed matter to biology. Electronic detectors are now used in most applications in EM as they offer convenience and immediate feedback that is not possible with film or image plates. The earliest forms of electronic detector used routinely in transmission electron microscopy (TEM) were charge coupled devices (CCDs) and for many applications these remain perfectly adequate. There are however applications, such as the study of radiation-sensitive biological samples, where film is still used and improved detectors would be of great value. The emphasis in this review is therefore on detectors for use in such applications. Two of the most promising candidates for improved detection are: monolithic active pixel sensors (MAPS) and hybrid pixel detectors (of which Medipix2 was chosen for this study). From the studies described in this review, a back-thinned MAPS detector appears well suited to replace film in for the study of radiation-sensitive samples at 300 keV, while Medipix2 is suited to use at lower energies and especially in situations with very low count rates. The performance of a detector depends on the energy of electrons to be recorded, which in turn is dependent on the application it is being used for; results are described for a wide range of electron energies ranging from 40 to 300 keV. The basic properties of detectors are discussed in terms of their modulation transfer function (MTF) and detective quantum efficiency (DQE) as a function of spatial frequency.

  6. L3 detector: BGO assembly

    CERN Multimedia

    CERN

    1989-01-01

    Explanation and presentation of its construction ( Feb-March 1989). The detector is a multi-layered cylindrical set of different devices, each of them measuring physical quantities relevant to the reconstruction of the collision under study. The three main outer layers are the electro-magnetic calorimeter (also called BGO because it's made of Bismuth Germanium Oxide), the hadronic calorimeter (HCAL) and the muon detector.

  7. Instrumentation of the fast detector

    CERN Document Server

    Barczyk, A.; Malgeri, L.; Casella, C.; Pohl, M.; Deiters, K.; Dick, P.; Berdugo, J.; Casaus, J.; Mana, C.; Marin, J.; Martinez, G.; Sanchez, E.; Willmott, C.

    2008-01-01

    The Fiber Active Scintillator Target (FAST) is an imaging particle detector intended for high precision muon lifetime measurement. This measurement will lead to a determination of the Fermi coupling constant (GF) with an uncertainty of 1 ppm, one order of magnitude better than the current world average. This contribution presents a description of the detector instrumentation and the first results, which have validated the design of the system.

  8. The SELEX Phototube RICH Detector

    CERN Document Server

    Engelfried, J; Kilmer, J; Kozhevnikov, A P; Kubarovskii, V P; Molchanov, V V; Nemitkin, A V; Ramberg, E; Rud, V I; Stutte, L

    1999-01-01

    In this article, construction, operation, and performance of the RICH detector of Fermilab experiment 781 (SELEX) are described. The detector utilizes a matrix of 2848 phototubes for the photocathode to detect Cherenkov photons generated in a 10m Neon radiator. For the central region an N0 of 104/cm, corresponding to 13.6 hits on a beta=1 ring, was obtained. The ring radius resolution measured is 1.6%.

  9. The SELEX phototube RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Engelfried, J.; Filimonov, I.; Kilmer, J.; Kozhevnikov, A.; Kubarovsky, V.; Molchanov, V.; Nemitkin, A.; Ramberg, E.; Rud, V.; Stutte, L

    1999-07-11

    In this article, construction, operation, and performance of the RICH detector of Fermilab experiment 781 (SELEX) are described. The detector utilizes a matrix of 2848 phototubes for the photocathode to detect Cherenkov photons generated in a 10 m neon radiator. For the central region an N{sub 0} of 104 cm{sup -1}, corresponding to 13.6 hits on a {beta}=1 ring, was obtained. The ring radius resolution measured is 1.6%. (author)

  10. The SELEX phototube RICH detector

    Science.gov (United States)

    Engelfried, J.; Filimonov, I.; Kilmer, J.; Kozhevnikov, A.; Kubarovsky, V.; Molchanov, V.; Nemitkin, A.; Ramberg, E.; Rud, V.; Stutte, L.

    1999-07-01

    In this article, construction, operation, and performance of the RICH detector of Fermilab experiment 781 (SELEX) are described. The detector utilizes a matrix of 2848 phototubes for the photocathode to detect Cherenkov photons generated in a 10 m neon radiator. For the central region an N0 of 104 cm-1, corresponding to 13.6 hits on a β=1 ring, was obtained. The ring radius resolution measured is 1.6%.

  11. New class of neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Czirr, J.B.

    1997-09-01

    An optimized neutron scattering instrument design must include all significant components, including the detector. For example, useful beam intensity is limited by detector dead time; detector pixel size determines the optimum beam diameter, sample size, and sample to detector distance; and detector efficiency vs. wavelength determines the available energy range. As an example of the next generation of detectors that could affect overall instrumentation design, we will describe a new scintillator material that is potentially superior to currently available scintillators. We have grown and tested several small, single crystal scintillators based upon the general class of cerium-activated lithium lanthanide borates. The outstanding characteristic of these materials is the high scintillation efficiency-as much as five times that of Li-glass scintillators. This increase in light output permits the practical use of the exothermic B (n, alpha) reaction for low energy neutron detection. This reaction provides a four-fold increase in capture cross section relative to the Li (n, alpha) reaction, and the intriguing possibility of demanding a charged-particle/gamma ray coincidence to reduce background detection rates. These new materials will be useful in the thermal and epithermal energy ran at reactors and pulsed neutron sources.

  12. DUAL-BAND INFRARED DETECTORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two-color HgCdTe photodiodes and quantum well infrared photodetectors is presented.More attention is devoted to HgCdTe detectors. The two-color detector arrays are based upon an n-P-N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p-n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials.Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP's narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.

  13. Handheld ultrasound concealed weapons detector

    Science.gov (United States)

    Felber, Franklin S.; Wild, Norbert C.; Nunan, Scott C.; Breuner, Dennis; Doft, Frank

    1998-12-01

    A handheld, battery-operated prototype of a remove concealed weapons detector has been built and tested. The concealed weapons detector will enable law enforcement and security officers to detect metallic and nonmetallic weapons concealed beneath clothing remotely from beyond arm's length to about 20 feet. These detectors may be used to: (1) allow hands-off, stand-off frisking of suspects for metallic and nonmetallic weapons; and (2) search for metallic and nonmetallic weapons on cooperative subjects at courthouse entrances and other monitored security portals. We have demonstrated that we image weapons concealed under heavy clothing, not just detect them, at ranges up to 15 feet using the same ultrasound frequency (40 kHz) used by commercial rangefinders. The concealed weapons detector operates much as a rangefinder, but at higher peak fluxes and pulse repetition frequencies. The detector alerts the user to concealed weapons audibly and visibly by detecting ultrasound glints above a body/clothing baseline, and by compensating for changing range and attenuation. The detector locates concealed weapons within a 6-inch illuminated spot at 10 feet. The signal processor eliminates any signal from behind the target.

  14. Physics Results from the AMANDA Neutrino Detector

    CERN Document Server

    Ahrens, J; Bai, X; Barouch, G; Barwick, S W; Bay, R C; Becka, T; Becker, K; Bertrand, D; Biron, A; Boser, S; Booth, J R A; Botner, O; Bouchta, A; Boyce, M M; Carius, S; Chen, A; Chirkin, D; Conrad, J; Cooley, J; Costa, C G S; Cowen, D F; De Clercq, C; De Young, T; Desiati, P; Dewulf, J P; Doksus, P; Edsjö, J; Ekstrom, P; Feser, T; Frère, J M; Gaug, M; Gerhardt, L; Goldschmidt, A; Hallgren, A; Halzen, F; Hanson, K; Hardtke, R; Hauschildt, T; Hellwig, M; Herquet, P; Hill, C G; Hulth, P O; Hundertmark, S; Jacobsen, J; Karle, A; Kim, J; Koci, B; Köpke, L; Kühn, K; Lamoureux, J I; Leich, H; Leuthold, M; Lindahl, P; Madsen, J; Marciniewski, P; Matis, H S; Minaeva, Y; Miocinovic, P; Morse, R; Neunhoffer, T; Niessen, P; Nygren, D R; Ogelman, H; Olbrechts, P; Perez de los Heros, C; Pohl, A; Price, P B; Przybylski, G T; Rawlins, K; Reed, C; Rhode, W; Ribordy, M; Richter, S; Martino, J R; Romenesko, P; Ross, D; Sander, H G; Schmidt, T; Schneider, D; Silvestri, A; Solarz, M; Spiczak, G M; Spiering, C; Starinsky, N; Steele, D; Steffen, P; Stokstad, R G; Sudhoff, P; Sulanke, K H; Taboada, I; Donckt, M V; Walck, C; Weinheimer, C; Wiebusch, C H; Wischnewski, R; Wissing, H; Woschnagg, K; Yodh, G; Young, S

    2001-01-01

    In the winter season of 2000, the AMANDA (Antarctic Muon And Neutrino Detector Array) detector was completed to its final state. We report on major physics results obtained from the AMANDA-B10 detector, as well as initial results of the full AMANDA-II detector.

  15. Performance of Ultra-Fast Silicon Detectors

    CERN Document Server

    Cartiglia, N; Ely, S; Fadeyev, V; Galloway, Z; Marchetto, F; Mazza, G; Ngo, J; Obertino, M; Parker, C; Rivetti, A; Shumacher, D; Sadrozinski, H F-W; Seiden, A; Zatserklyaniy, A

    2013-01-01

    The development of Low-Gain Avalanche Detectors has opened up the possibility of manufacturing silicon detectors with signal larger than that of traditional sensors. In this paper we explore the timing performance of Low-Gain Avalanche Detectors, and in particular we demonstrate the possibility of obtaining ultra-fast silicon detector with time resolution of less than 20 picosecond.

  16. Two-dimensional microstrip detector for neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Oed, A. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Because of their robust design, gas microstrip detectors, which were developed at ILL, can be assembled relatively quickly, provided the prefabricated components are available. At the beginning of 1996, orders were received for the construction of three two-dimensional neutron detectors. These detectors have been completed. The detectors are outlined below. (author). 2 refs.

  17. Advanced Space Radiation Detector Technology Development

    Science.gov (United States)

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

    2013-01-01

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

  18. Redesigned β γ radioxenon detector

    Science.gov (United States)

    Cooper, Matthew W.; McIntyre, Justin I.; Bowyer, Ted W.; Carman, April J.; Hayes, James C.; Heimbigner, Tom R.; Hubbard, Charles W.; Lidey, Lance; Litke, Kevin E.; Morris, Scott J.; Ripplinger, Michael D.; Suarez, Reynold; Thompson, Robert

    2007-08-01

    The Automated Radio-xenon Sampler/Analyzer (ARSA), designed by Pacific Northwest National Laboratory (PNNL) collects and detects several radioxenon isotopes, and is used to monitor underground nuclear explosions. The ARSA is very sensitive to 133Xe, 131mXe, 133mXe, and 135Xe (SCM) [M. Auera et al., Wernspergera, Appl. Radiat. 6 (2004) 60] through use of its compact high efficiency β-γ coincidence detector. For this reason, it is an excellent treaty monitoring system and it can be used as an environmental sampling device as well. Field testing of the ARSA has shown it to be both robust and reliable, but the nuclear detector requires a detailed photomultiplier tube (PMT) gain matching regime difficult to implement in a field environment. Complexity is a problem from a maintenance and quality assurance/quality control (QA/QC) standpoint, and efforts to reduce these issues have led to development of a simplified β-γ coincident detector. The new design reduces the number of PMT's and the complexity of the calibration needed in comparison to the old design. New scintillation materials (NaI(Tl), CsI(Na), and CsI(Tl)) were investigated and a comparison of three different gamma sensitive well detectors has been completed. A new plastic-scintillator gas cell was constructed and a new method of forming the scintillator gas cell was developed. The simplified detector system compares favorably with the original ARSA design in spectral resolution and efficiency and is significantly easier to set up and calibrate. The new materials and configuration allow the resulting β-γ coincidence detector to maintain the overall performance of the ARSA type β-γ detector while simplifying the design.

  19. Prompt fission neutron investigation in 235U(nth,f) reaction

    Science.gov (United States)

    Zeynalov, Shakir; Sedyshev, Pavel; Shvetsov, Valery; Sidorova, Olga

    2017-09-01

    The prompt neutron emission in thermal neutron induced fission of 235U has been investigated applying digital signal electronics. The goal was to compare the results of this digital data acquisition and digital signal processing analysis to the results of the pioneering work of Apalin et al. Using a twin Frisch grid ionization chamber for the fission fragment detection and a NE213 equivalent neutron detector in total about 106 neutron coincidences have been registered. The fission fragment kinetic energy, mass and angular distribution has been investigated along with prompt neutron time of flight and pulse shape using a six channel synchronous waveform digitizer with sampling frequency of 250 MHz and 12 bit resolution. The signals have been analyzed using digital pulse processing algorithms, developed by authors. The thermal neutron beam was transported from the IBR-2 reactor to the target with bent mirror neutron guide.

  20. Neutron-induced fission cross section of 242Pu from 15 MeV to 20 MeV

    Directory of Open Access Journals (Sweden)

    Jovančević N.

    2017-01-01

    Full Text Available Accurate nuclear-data needs in the fast-neutron-energy region have been recently addressed for the development of next generation nuclear power plants (GEN-IV by the OECD Nuclear Energy Agency (NEA. This sensitivity study has shown that of particular interest is the 242Pu(n,f cross section for fast reactor systems. Measurements have been performed with quasi-monoenergetic neutrons in the energy range from 15 MeV to 20 MeV produced by the Van de Graaff accelerator of the JRC-Geel. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission fragment detector. The 242Pu(n,f cross section has been normalized to 238U(n,f cross section data. The results were compared with existing literature data and show acceptable agreement within 5%.