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Nuclear Science, IEEE Transactions on

Issue 4  Part 1 • Date Aug. 2001

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Displaying Results 1 - 25 of 74
  • Performance of irradiated and nonirradiated 500-/spl mu/m-thick silicon microstrip detectors

    Publication Year: 2001 , Page(s): 1016 - 1019
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (76 KB) |  | HTML iconHTML  

    The decision taken by the CMS experiment to build a tracker entirely based on silicon detectors has made necessary the use of thicker sensors instead of the usual 300-/spl mu/m sensors for the outer part of the detector. We first present results on the performance of 500-/spl mu/m-thick detectors, before and after neutron irradiation, bonded to the CMS tracker front-end electronics. Laboratory measurements show that the total collected charge scales linearly with thickness when compared with a 300-/spl mu/m module, and the measured noise is in good agreement with expectations. The results obtained confirm the feasibility of large-area silicon trackers. View full abstract»

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  • An argon gas proportional scintillation counter with UV avalanche photodiode scintillation readout

    Publication Year: 2001 , Page(s): 1081 - 1086
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (111 KB) |  | HTML iconHTML  

    An uniform-field argon-filled gas proportional scintillation counter, using a large-area avalanche photodiode, is presented. The excitation and ionization thresholds for argon were found to be approximately 0.7 and 3.7 V cm/sup -1/ torr/sup -1/, respectively. An upper limit of 0.30/spl plusmn/0.04 was measured for the argon Fano factor for 5.9-keV X-rays. An energy resolution of 12.5% full-width-at-half-maximum was achieved for 5.9-keV X-rays. The ultraviolet large-area avalanche photodiode proved to be suitable for reading the scintillation light of an argon-filled gas proportional scintillation counter, providing a quantum efficiency of about 50% at 128 nm. Good photodiode performance is already achieved for gains about 100. View full abstract»

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  • Conference author index

    Publication Year: 2001 , Page(s): 1336 - 1338
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    Freely Available from IEEE
  • An upgraded data-acquisition system for the balloon-borne liquid xenon γ-ray imaging telescope LXeGRIT

    Publication Year: 2001 , Page(s): 1299 - 1305
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB) |  | HTML iconHTML  

    LXeGRIT is a balloon-borne Compton telescope for MeV γ-ray astrophysics, based on a liquid xenon time projection chamber (LXeTPC) with charge and light readout. The first balloon flights in 1997 revealed limitations of the trigger electronics and the data-acquisition (DAQ) system, leading to their upgrade. New electronics was developed to handle the xenon scintillation light trigger. The original processor module was replaced by a commercial VME processor. The telemetry rate was doubled to 2×500 kbps and onboard data storage on hard disks was implemented. Relying on a robust real-time operating system, the new DAQ software adopts an object-oriented design to implement the diverse tasks of trigger handling, data selection, transmission, and storage, as well as DAQ control and monitor functions. The new systems performed well during two flights in spring 1999 and fall 2000. In the 2000 flight, the DAQ system was able to handle 300-350 triggers/s out of a total of about 650 Hz, including charged particles View full abstract»

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  • System for visualization of radionuclide distribution in samples of mountain rock

    Publication Year: 2001 , Page(s): 1190 - 1193
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (112 KB) |  | HTML iconHTML  

    The system for visualization of radionuclide distribution in samples of mountain rock is based on a combined detector: scintillating plate + image intensifier + charge-coupled device sensor. At optimal choice of voltages, its sensitivity allows the detection of single photons with energy higher than 60 keV. The specially prepared samples are located directly on a thin metal holder of a crystal. The detector has a spatial resolution of 0.3 mm. The developed technique of measuring and digital processing of raw images resulted in two-dimensional maps of the radionuclide distributions and shadow X-ray images of samples. Superposition of the images gives coordinate positioning in measured distributions. For separation of gamma and beta radiation of the samples, filters of various thickness were applied. Examples of images of rock slices with natural radionuclides and samples with technogenic pollution are presented View full abstract»

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  • Spectroscopic-grade X-ray imaging up to 100-kHz frame rate with controlled-drift detectors

    Publication Year: 2001 , Page(s): 982 - 986
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    Controlled-drift detectors are fully depleted silicon detectors for X-ray imaging that combine good position resolution with very fast frame readout. The basic feature of the controlled-drift detector is the transport of the charge packets stored in each pixel column to the output electrode by means of a uniform drift field. The drift time of the charge packet identifies the pixel of incidence. Images of an X-ray source obtained with the controlled-drift detector up to 100-kHz frame rate are presented and discussed. The achievable energy resolution as a function of the operating temperature and frame rate is analyzed View full abstract»

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  • Thin photodiodes for a neutron scintillator silicon-well detector

    Publication Year: 2001 , Page(s): 1154 - 1157
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (88 KB) |  | HTML iconHTML  

    In the development of new neutron imaging applications, it is crucial to achieve a detector combining high spatial resolution, fast response, and high detection efficiency. To achieve such features, we have proposed a new design for position sensitive radiation sensors, which we called the micromachined Si-well scintillator pixel detector. It consists of an array of scintillator crystals encapsulated in silicon wells with photodiodes at the bottom. In the following, we describe such a detector, which makes use of a powder of 6Li6 158Gd(BO3)3(Ce3+). The first experiments obtained with a prototype detector using a thermal neutron beam show the presence of a signal above the detector noise tail. In addition, to improve the characteristics of the well-type silicon sensor, we have investigated the deep reactive ion etching on silicon-on-insulator wafers. The process to etch 700-μm-wide vertical wells into a 500-μm-thick silicon wafer has been optimized. Test detectors with 10-μm-thick photodiodes at the bottom have been fabricated by means of this process View full abstract»

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  • Radiation hardness of oxygenated microstrip detectors read out with LHC speed electronics

    Publication Year: 2001 , Page(s): 1007 - 1011
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    Full-size and miniature Large Hadron Collider (LHC) detectors fabricated on 4- and 6-in wafers have been processed using oxygenated and nonoxygenated substrates. After irradiation to 3×1014 /cm2 with 24-GeV/c protons and short-term annealing, these detectors have been studied in terms of their charge collection as a function of depletion voltage with LHC-speed analog electronics. Results are presented indicating the degree of improvement seen in terms of the main operationally significant parameter, namely, the bias voltage needed for a given signal read out with fast electronics View full abstract»

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  • A dip detector for in situ measuring of Cs-137 specific soil activity profiles

    Publication Year: 2001 , Page(s): 1194 - 1197
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (88 KB)  

    A field method for measurement of Cs-137 contamination depth profiles is described. The method is based on the use of a collimated dip detector created as a gamma-ray probe: CsI(Tl) scintillating crystal + PIN photodiode + front-end electronics. The presented method allows determination of specific activity distribution with vertical spatial resolution of 5 cm. Exposure time for one point in the distribution profile is less than 180 s if the level of specific activity is more than 50 Bq/kg. This method may be applied for efficient and quick inspection of a contaminated river's flood planes in areas with leakage of radioactive wastes. Application of the method for such a task gives an effective solution to obtain qualitative and quantitative characteristics of contamination View full abstract»

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  • Recent progress in CdTe and CdZnTe detectors

    Publication Year: 2001 , Page(s): 950 - 959
    Cited by:  Papers (100)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB)  

    Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) have been regarded as promising semiconductor materials for hard X-ray and γ-ray detection. The high atomic number of the materials (ZCd =48, ZTe=52) gives a high quantum efficiency in comparison with Si. The large bandgap energy (Eg~1.5 eV) allows us to operate the detector at room temperature. However, a considerable amount of charge loss in these detectors produces a reduced energy resolution. This problem arises due to the low mobility and short lifetime of holes. Recently, significant improvements have been achieved to improve the spectral properties based on the advances in the production of crystals and in the design of electrodes. In this paper we summarize 1) advantages and disadvantages of CdTe and CdZnTe semiconductor detectors and 2) the technique for improving energy resolution and photopeak efficiencies. Applications of these imaging detectors in future hard X-ray and γ-ray astronomy missions are briefly discussed View full abstract»

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  • Landmine detection with the neutron backscattering method

    Publication Year: 2001 , Page(s): 1087 - 1091
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (144 KB) |  | HTML iconHTML  

    Neutron backscattering was selected as a promising new method for the detection of landmines. With this technique, 252Cf source and a thermal neutron detector are used. Fast neutrons from the Californium source are better moderated by the landmine, especially plastic mines, than in the surrounding soil. This leads to an increase in the number of reflected thermal neutrons above the mine. Results from experimental trials with the Delft University Neutron Backscattering Landmine Detector (DUNBLAD) are presented and compared with results from Monte Carlo simulations. The limitations of this method and the radiation dose for the user are investigated. Based on these results, a new portable prototype detector is presented View full abstract»

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  • Implementation of the ASDBLR straw tube readout ASIC in DMILL technology

    Publication Year: 2001 , Page(s): 1239 - 1243
    Cited by:  Papers (6)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (75 KB) |  | HTML iconHTML  

    The ASDBLR application-specific integrated circuit (ASIC) provides eight channels of low-noise low-power high-rate on-detector readout suitable for the ATLAS transition radiation tracker (TRT) at the large hadron collider. The TRT's unprecedented wire chamber readout requirements of a maximum hit rate per wire of 20 MHz and double-pulse resolution of ~25 ns with position resolution of better than 150 μm in a high radiation environment have been addressed in the design of the ASDBLR. A carefully tuned ion tail cancellation stage followed by an output sensing baseline restorer implemented in differential structures provides robust signal-processing combination compatible with the realities of ASIC design. Two comparators track the output of the signal-processing stage to provide tracking information from charged particles and evidence of higher energy transition radiation photons; their outputs are summed as current steps to form a differential ternary output. The ten-year total dose requirement for neutrons of 1014 n/cm2 and 1.5 MRad of ionizing radiation led to the implementation of this design in the radiation hardened DMILL process View full abstract»

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  • Characterization of thin back-to-back CdTe detectors

    Publication Year: 2001 , Page(s): 1028 - 1032
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB) |  | HTML iconHTML  

    Thin CdTe detectors (3×5 mm2 electrode area, 0.5 and 0.8 mm thick), mounted in back-to-back configuration with common anode have been characterized. This configuration allows one to double the useful absorbing thickness in the classical planar parallel field (PPF) irradiation geometry and to double the sensitive area in the planar transverse field (PTF) geometry, while maintaining the same interelectrode distance (0.5 or 0.8 mm) and one electronic chain as for single detectors. The tests performed aim at understanding the effects on the spectroscopic performance of various interelectrode distances and in particular of the chemical and mechanical treatments used to make thin detectors. A narrow photon beam, 10-150 keV in energy, obtained using a 20-mm-thick tungsten collimator, was employed. The results obtained, compared with previous measurements on various thicknesses devices, indicate that the optimum single detector thickness is 1 mm View full abstract»

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  • Spectroscopic technique for optimal P-Z setting in γ-ray detection

    Publication Year: 2001 , Page(s): 1234 - 1238
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (112 KB) |  | HTML iconHTML  

    A spectroscopic technique for optimally setting the pole-zero (P-Z) compensation in a digital spectrometer has been implemented, which has substantially improved the resolution of the measurements at high count rates. Before analog-to-digital conversion, the signal undergoes an analog preprocessing, consisting of P-Z compensation and simple three-pole shaping, which is the proper antialiasing-filter shape in this context. A subsequent suitable digital filter optimizes the overall weight function and introduces digital baseline restoration. It is well known that an imperfect P-Z setting causes pulse-tail pileup which is seen as an additional noise and may impact significantly on the final resolution of the measurements, particularly at high count rates. A spectroscopic technique which permits a second-order tuning of the P-Z compensation is proposed. Such a fine-tuning degree yields a substantial improvement in the performance of the system. Namely, at a count rate of 24 kcounts/s the second-order tuning (1% adjustment) yields a 30% narrowing of the 1.17 MeV 60Co line View full abstract»

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  • A gaseous muon detector at the HERA-B experiment

    Publication Year: 2001 , Page(s): 1059 - 1064
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (128 KB) |  | HTML iconHTML  

    The muon detector of the HERA-B experiment at DESY (Hamburg, Germany) is a gaseous detector that provides muon identification in a high-rate environment. Pairs of muons with an invariant mass in the region of the J/ψ, meson ensure the first-level trigger for the experiment. Three different types of gas proportional chambers are employed: tube, pad, and pixel. The muon detector is fully installed and has been continuously running since November 1999. A clear signal for J/ψ→μμ, is reconstructed from data taken during the commissioning run. Design of the muon system as well as experience gained with detector commissioning are presented in this paper. The severe radiation environment of the HERA-B experiment leads to a maximum charge deposit on a wire, within the muon detector, of 200 mC/cm per year. We report recent results of aging studies performed by irradiating proportional wire chambers filled with Ar/CF4,/CK and Ar/CF 4/CO2 mixtures under various conditions. These results show that aging rates obtained by irradiating a small region of the wire with a radioactive source cannot be extrapolated to the irradiation of large areas in an environment of hadronic interactions. Our experience shows that the aging rate depends not only on the total collected charge but also on the mode of operation and area of irradiation View full abstract»

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  • Analytical model for the ohmic-side interstrip resistance of double-sided silicon microstrip detectors

    Publication Year: 2001 , Page(s): 972 - 976
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    A compact, analytical model is derived for the n-side interstrip resistance of double-sided silicon microstrip detectors, allowing for fast and accurate prediction of the minimum p-stop (or p-spray) implant dose ensuring adequate interstrip isolation. The basic idea on which the proposed model relies is that the portion of the detector between two adjacent n-strips can effectively be reduced to an equivalent n-channel MOSFET. The interstrip resistance can be evaluated as the output resistance of this equivalent MOSFET using standard SPICE-like models. The influence of radiation-induced oxide charge and p-stop (or p-spray) voltage can be accounted for by simply including, in the threshold voltage expression, the induced flat-band voltage shift and body-effect term, respectively View full abstract»

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  • Beam dump for high-current electron beam at JNC

    Publication Year: 2001 , Page(s): 1329 - 1335
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB) |  | HTML iconHTML  

    A high current electron beam is required for transmuting fission products using γ-rays. Elemental technology for a linac that generates a high current beam in an efficient and stable manner is being developed at the Japan Nuclear Cycle Development Institute (JNC). A beam dump for the high current, low energy electron beam (20 mA, 10 MeV) from this accelerator has been constructed and tested at JNC. A ring-and-disk structure was adopted to absorb the beam safely and to analyze the beam condition in real time. The thermal and stress analysis showed that a 200-kW electron beam could be securely stopped. The performance of the beam dump was evaluated using a beam of 7.0 MeV and an average current of 0.84 mA. The measured results showed that the electrons transported from the accelerator were completely absorbed. In addition, the beam dump was found to be capable of monitoring the beam condition directly from the temperature distributions and peak current View full abstract»

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  • A simple method of energy calibration for thin plastic scintillator

    Publication Year: 2001 , Page(s): 1172 - 1176
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (136 KB) |  | HTML iconHTML  

    A thin plastic scintillator is used as a trigger counter in a charged particle spectrometer. Since its Compton edge is not clear, it is difficult to test the thin plastic scintillator counter with a standard gamma-ray source. In this paper, a simple method is proposed to determine the Compton edge and the energy resolution of the thin plastic scintillator by fitting the simulated spectrum to the measured spectrum. The simulated spectrum was made with a Monte Carlo program utilizing the geometry of the plastic scintillator. This technique was examined with three different plastic scintillators View full abstract»

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  • The new scintillating fiber detector of E835 at Fermilab

    Publication Year: 2001 , Page(s): 1122 - 1126
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (152 KB) |  | HTML iconHTML  

    A cylindrical scintillating fiber detector for the measurement of the polar coordinate θ has been built for experiment E835 at Fermilab. This is the first detector used in a high-energy physics experiment that exploits scintillating fibers and visible light photon counters (VLPCs). It combines the high granularity, flexibility, and fast response of the scintillating fibers with the high quantum efficiency of the VLPCs. Complete results about tracking resolution, detection efficiency, time resolution, long-term stability, and reliability are given View full abstract»

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  • Performance of the light trigger system in the liquid xenon γ-ray imaging telescope LXeGRIT

    Publication Year: 2001 , Page(s): 1041 - 1047
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (208 KB)  

    LXeGRIT is a balloon-borne Compton telescope for MeV γ-ray astrophysics, based on a liquid xenon time projection chamber with charge and light readout. The energy and direction of an incident γ-ray are reconstructed from the three-dimensional locations and energy deposits of individual interactions taking place in the homogeneous detector volume. While the charge signals provide energy information and X-Y-positions, the fast xenon scintillation light signal is used to trigger the detector. The drift time measurement, referred to the time of the trigger signal, gives the Z-position with the known drift velocity. The light is detected by four ultraviolet-sensitive photomultiplier tubes (PMTs). The logical OR of the PMT signals triggers the data-acquisition system with an efficiency that depends on the event energy and location, as well as on the discriminator thresholds used on the individual PMTs. Results from experiments with a tagged 22Na source give the spatial distribution of the light trigger efficiency for 511-keV γ-rays. When averaged over the whole sensitive volume and all PMTs, the trigger efficiency is 47% or 40% for two discriminator windows used during the LXeGRIT balloon flight of 1999. These values are strongly affected by the different sensitivity of each PMT. The corresponding average efficiency at 511 keV for the best of the four PMTs is in fact 63% and approaches 100% for interactions taking place in a small volume right above the PMT View full abstract»

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  • GEM detectors for COMPASS

    Publication Year: 2001 , Page(s): 1065 - 1069
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (160 KB) |  | HTML iconHTML  

    For the small-area tracking of particles within COMPASS (common muon and proton apparatus for structure and spectroscopy), a new fixed target experiment at CERN/SPS, several large-size(31×31 cm2 ) detectors based on the gas electron multiplier (GEM), have been built. These new devices, consisting of several GEM amplification stages with a two-coordinate readout, combine good spatial resolution with high rate capability, which is required by the large particle flux near the beam. At the same time, the material exposed to the beam is minimized in order not to spoil the mass resolution of the spectrometer. The first detectors out of a total of 20 were subject to extensive tests in the beam and in the laboratory, showing that full (i.e., >98%) detection efficiency for minimum ionizing particles can be achieved at a total effective gain of 6000. Ongoing research work focuses on discharges triggered by heavily ionizing particles entering the detectors. Systematic studies of the energy released in discharges and their probability of occuring at all as a function of a variety of parameters suggest several means to minimize their impact on detector performance. First results of the operational characteristics of these detectors in the real COMPASS beam are presented View full abstract»

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  • Error handling for the CDF online silicon vertex tracker

    Publication Year: 2001 , Page(s): 1286 - 1289
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (73 KB) |  | HTML iconHTML  

    The online silicon vertex tracker (SVT) is composed of 104 VME 9U digital boards (of eight different types). Since the data output from the SVT (few MB/s) are a small fraction of the input data (200 MB/s), it is extremely difficult to track possible internal errors by using only the output stream. For this reason, several diagnostic tools have been implemented: local error registers, error bits propagated through the data streams, and the Spy Buffer system. Data flowing through each input and output stream of every board are continuously copied to memory banks named spy buffers, which act as built-in logic state analyzers hooked continuously to internal data streams. The contents of all buffers can be frozen at any time (e.g., on error detection) to take a snapshot of all data flowing through each SVT board. The spy buffers are coordinated at system level by the Spy Control Board. The architecture, design, and implementation of this system are described View full abstract»

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  • Hybrid pixel detector development for the linear collider vertex detector

    Publication Year: 2001 , Page(s): 992 - 996
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (120 KB) |  | HTML iconHTML  

    To fully exploit the physics potential of future high-energy e+e$linear colliders, a vertex detector providing high-resolution track reconstruction is required. Hybrid silicon pixel detectors are an attractive option for the sensor technology due to their readout speed and radiation hardness but have been so far limited by the achievable single-point resolution. A novel layout of a hybrid pixel sensor with interleaved cells to improve the spatial resolution has been developed. The characterization of the first processed prototypes is reported View full abstract»

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  • A small scintillating fiber camera consisting of 0.25-mm square fibers for space dosimetry

    Publication Year: 2001 , Page(s): 1118 - 1121
    Cited by:  Papers (1)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (89 KB) |  | HTML iconHTML  

    A small scintillating fiber camera for space dosimetry was developed. The camera consists of a scintillating fiber stack bundled with 0.25-mm square fibers, two image intensifier units whose input windows are 40 mm in diameter, and two photomultipliers. Neutron events are distinguished from gamma-ray events by observing three-dimensional track images of recoil protons and electrons. Experimental results show that events caused by recoil protons with energies above 5 MeV can be distinguished from gamma-ray events. The purpose of this camera is to evaluate the LET, of charged particles produced in the interaction of neutrons with the nucleus in scintillating fibers. The camera is expected to measure the dose contribution from higher energy neutron, especially, more than ~10 MeV, which is the upper limit energy of the present measurement in space View full abstract»

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  • Simulations of electric potential and field profiles in Si microstrip detectors using the guard-strip concept

    Publication Year: 2001 , Page(s): 977 - 981
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (160 KB) |  | HTML iconHTML  

    Two-dimensional (2-D) simulations of the electrical properties of Si microstrip detectors with various strip width/pitch configurations have been systematically performed using a processing and device simulation tool. It has been found that the detector full depletion voltage (Vfd) depends greatly on the ratios of strip width (W) to pitch (P) and pitch to detector thickness (d). Vfd increases with the decreasing ratio of W/P:Vfd for W/P=0.1(P=100 μm) and is almost twice that of a bulk detector (W/P=1) for different bulk resistivities (simulation of before and after radiation). The increasing rate of Vfd with decreasing W/P is much higher when W/P<0.3. It has also been found that, for a given strip width, the strip pitch should be kept smaller than the sum of detector thickness and strip width, i.e., P<d+W or P<d (if W≪d). Otherwise, the value of Vfd will be affected significantly (much larger than that of a bulk detector), It is clearly shown through the simulation that this increase of Vfd is due to the lateral depletion from the strip edge. A new width/pitch configuration with guard strips is proposed, which has shown great promise to push the W/P ratio down to 0.1 without greatly affecting the detector full depletion voltage View full abstract»

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