Radiation Detectors

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Ali Mirzaei - One of the best experts on this subject based on the ideXlab platform.

  • Room Temperature Hard Radiation Detectors Based on Solid State Compound Semiconductors: An Overview
    Electronic Materials Letters, 2018
    Co-Authors: Ali Mirzaei
    Abstract:

    Si and Ge single crystals are the most common semiconductor Radiation Detectors. However, they need to work at cryogenic temperatures to decrease their noise levels. In contrast, compound semiconductors can be operated at room temperature due to their ability to grow compound materials with tunable densities, band gaps and atomic numbers. Highly efficient room temperature hard Radiation Detectors can be utilized in biomedical diagnostics, nuclear safety and homeland security applications. In this review, we discuss room temperature compound semiconductors. Since the field of Radiation detection is broad and a discussion of all compound materials for Radiation sensing is impossible, we discuss the most important materials for the detection of hard Radiation with a focus on binary heavy metal semiconductors and ternary and quaternary chalcogenide compounds. Graphical Abstract

M A Plano - One of the best experts on this subject based on the ideXlab platform.

  • diamond Radiation Detectors
    Diamond and Related Materials, 1993
    Co-Authors: D R Kania, M I Landstrass, M A Plano
    Abstract:

    Abstract Diamond Radiation Detectors have a lengthy history. Photoconductive UV Detectors were developed in the 1920s and ionizing Radiation Detectors were created in the 1940s. However, these devices encountered restricted usage owing to the limitations of natural diamonds. Specifically, these limitations were the small size and lack of control of the material characteristics. Recent advances in the high quality growth of diamond by chemical vapor deposition have created the opportunity for the application of this material in practical Detectors.

Y. Hiratate - One of the best experts on this subject based on the ideXlab platform.

  • Thallium lead iodide Radiation Detectors
    IEEE Transactions on Nuclear Science, 2003
    Co-Authors: K. Hitomi, T. Onodera, T. Shoji, Y. Hiratate
    Abstract:

    Thallium lead iodide (TlPbI/sub 3/) is a compound semiconductor characterized with wide bandgap (2.3 eV) and high photon stopping power. TlPbI/sub 3/ is an attractive material for fabrication of room temperature Radiation Detectors. In this study, TlPbI/sub 3/ crystals were grown by the vertical Bridgman technique using zone-purified materials. The starting materials for the crystal growth were synthesized from commercially available TlI and PbI/sub 2/ powder with nominal purity of 99.99%. Powder X-ray diffraction analysis was performed to study chemical composition of the synthesized TlPbI/sub 3/. In order to fabricate Radiation Detectors, the grown crystals were cut into several wafers using a wire saw. The wafers were then polished using Al/sub 2/O/sub 3/ abrasives. Electrodes were formed on the wafers by vacuum evaporation of gold. The resultant TlPbI/sub 3/ Radiation Detectors were evaluated by measuring their current-voltage characteristics and spectral responses. Most TlPbI/sub 3/ Detectors exhibited resistivities higher than 10/sup 11//spl Omega/cm. The TlPbI/sub 3/ Detectors were irradiated with /spl alpha/-particles (5.48 MeV) from a /sup 241/Am source or /spl gamma/-rays (122 keV) from a /sup 57/Co source. The TlPbI/sub 3/ Detectors exhibited a clear peak of 5.48 MeV /spl alpha/-particles. Although the 122 keV peak was not resolved in the energy spectra, increased counts above the noise spectrum were observed by the present Detectors.

  • Thallium lead iodide Radiation Detectors
    2002 IEEE Nuclear Science Symposium Conference Record, 2002
    Co-Authors: K. Hitomi, T. Onodera, T. Shoji, Y. Hiratate
    Abstract:

    Thallium lead iodide (TlPbI/sub 3/) is a compound semiconductor characterized with wide band gap (2.3 eV) and high photon stopping power. Thus, TlPbI/sub 3/ is an attractive material for fabrication of room temperature Radiation Detectors. In this study, TlPbI/sub 3/ crystals were grown by the vertical Bridgman technique using zone-purified materials. The starting materials for the crystal growth were synthesized from commercially available TlI and PbI/sub 2/ powders with nominal purity of 99.99%. Powder X-ray diffraction analysis was performed to evaluate chemical composition of the synthesized TlPbI/sub 3/. In order to fabricate Radiation Detectors, the grown crystals were cut into several wafers using a wire saw. The wafers were then polished using Al/sub 2/O/sub 3/ abrasives. Electrodes were formed on the wafers by vacuum evaporation of gold. The resultant TlPbI/sub 3/ Radiation Detectors were evaluated by measuring their current-voltage characteristics and spectral responses. Most of TlPbI/sub 3/ Detectors exhibited resistivities more than 10/sup 11/ /spl Omega/cm. The TlPbI/sub 3/ Detectors were irradiated with /spl alpha/-particles (5.48 MeV) from a /sup 241/Am source or /spl gamma/-rays (662 keV) from a /sup 137/Cs source. The TlPbI/sub 3/ Detectors exhibited a clear peak of 5.48 MeV /spl alpha/-particles. Although the 662 keV peak was not resolved in the energy spectra, increased counts above the noise spectrum were observed for the Detectors. To our knowledge, it is the first time that TlPbI/sub 3/ Detectors exhibit /spl alpha/-particle spectra with a clear peak and /spl gamma/-ray spectra.

  • improved spectrometric characteristics of thallium bromide nuclear Radiation Detectors
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 1999
    Co-Authors: K. Hitomi, T. Shoji, T Murayama, T Suehiro, Y. Hiratate
    Abstract:

    Abstract Thallium bromide (TlBr) is a compound semiconductor with a high atomic number and wide band gap. In this study, nuclear Radiation Detectors have been fabricated from the TlBr crystals. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using the materials purified by many pass zone refining. The crystals were characterized by measuring the resistivity, the mobility–lifetime ( μτ ) product and the energy required to create an electron–hole pair (the e value). Improved energy resolution has been obtained by the TlBr Radiation Detectors. At room temperature the full-width at half-maximum (FWHM) for the 59.5, 122 and 662 keV γ-ray photo peak obtained from the Detectors were 3.3, 8.8 and 29.5 keV, respectively. By comparing the saturated peak position of the TlBr detector with that of the CdTe detector, the e value has been estimated to be about 5.85 eV for the TlBr crystal.

Frank H. Ruddy - One of the best experts on this subject based on the ideXlab platform.

  • fast neutron detection with silicon carbide semiconductor Radiation Detectors
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2007
    Co-Authors: Robert W Flammang, John G. Seidel, Frank H. Ruddy
    Abstract:

    Silicon carbide (SiC) Radiation Detectors are being developed for high-temperature applications in harsh Radiation environments. Among these applications are characterization of nuclear reactor fuel and detection of concealed fissionable materials, which both require the optimization of SiC fast neutron Detectors for detection and quantification of fission neutrons. In order to enhance fast-neutron sensitivity, proton recoil techniques are being used. Fission neutrons were simulated by using a 2.5-MeV deuterium-deuterium (D-D) neutron generator. In order to optimize the neutron detection sensitivity, 2.5-MeV neutron proton-recoil response measurements were made as a function of polyethylene converter layer thickness. Measurements were also made of the sensitivity of the SiC proton recoil detector as a function of angle of incidence of the neutrons. As expected from the angular sensitivity of the detector response, detection of neutrons normally incident to the detector face is favored allowing discrimination of background neutrons and possibly supplying information on the fissionable material location or configuration.

  • Effects of Gamma IrRadiation on Silicon Carbide Semiconductor Radiation Detectors
    2006 IEEE Nuclear Science Symposium Conference Record, 2006
    Co-Authors: Frank H. Ruddy, John G. Siedel
    Abstract:

    Silicon carbide (SiC) semiconductor Radiation Detectors are being developed for alpha-particle, X- and gamma-ray, and fast-neutron energy spectrometry. SiC Detectors have been operated at temperatures up to 306degC and have also been found to be highly resistant to the Radiation effects of fast-neutron and charged-particle bombardments. In the present work, the alpha-particle response of a SiC detector based on a Schottky diode design has been monitored as a function of 137Cs gamma-ray exposure. The changes in response have been found to be negligible for gamma-ray exposures up to and including 22.7 MGy, and irRadiations to higher doses are in progress. Results will be reported for alpha and fast-neutron response testing following cumulative doses up to 22.7 MGy.

  • The fast neutron response of silicon carbide semiconductor Radiation Detectors
    IEEE Symposium Conference Record Nuclear Science 2004., 2004
    Co-Authors: Frank H. Ruddy, Abdul R. Dulloo, John G. Seidel, A.k. Agarwal
    Abstract:

    Fast neutron response measurements are reported for Radiation Detectors based on large-volume SiC p-i-n diodes. Multiple reaction peaks are observed for 14-MeV neutron reactions with the silicon and carbon nuclides in the SiC detector. A high degree of linearity is observed for the /sup 28/Si(n,/spl alpha//sub 1/) reaction set of six energy levels in the product /sup 25/Mg nucleus, and pulse height defect differences between the observed /sup 12/C(n,/spl alpha//sub 0/) and /sup 28/Si(n,/spl alpha//sub 1/) energy responses are discussed. Energy spectrometry applications in fission and fusion neutron fields are also discussed.

  • The gamma-ray response of silicon carbide Radiation Detectors
    Transactions of the American Nuclear Society, 1998
    Co-Authors: Frank H. Ruddy, Abdul R. Dulloo, John G. Seidel
    Abstract:

    Silicon carbide (SiC) Radiation Detectors are being developed for charged-particle, neutron, and gamma-ray detection. SiC is a wide band gap semiconductor that offers several advantages for use as a solid-state Radiation detector. Among these are the ability of SiC devices to operate at elevated temperatures and their improved resistance to Radiation compared to other semiconductors. SiC charged-particle Detectors have been shown to have good energy resolution for alpha particles. Furthermore, pulse heights and full-widths at half-maximum were found to be completely unperturbed by changes in temperature up to 89 C. In subsequent measurements, SiC neutron Detectors based on detection of neutron-induced tritons from a juxtaposed {sup 6}LiF foil were shown to have a highly linear response to thermal neutron flux in the range from 1.76 {times} 10{sup 4} to 3.59 {times} 10{sup 10} cm{sup {minus}2}/s in National Institute of Standards and Technology neutron fields. An important attribute of SiC Radiation Detectors is their ability to operate in and monitor intense gamma-ray fields while in pulse-mode operation.

D R Kania - One of the best experts on this subject based on the ideXlab platform.

  • Diamond Radiation Detectors II. CVD diamond development for Radiation Detectors
    1997
    Co-Authors: D R Kania
    Abstract:

    Interest in Radiation Detectors has supplied some of the impetus for improving the electronic properties of CVD diamond. In the present discussion, we will restrict our attention to polycrystalhne CVD material. We will focus on the evolution of these materials over the past decade and the correlation of detector performance with other properties of the material.

  • diamond Radiation Detectors
    Diamond and Related Materials, 1993
    Co-Authors: D R Kania, M I Landstrass, M A Plano
    Abstract:

    Abstract Diamond Radiation Detectors have a lengthy history. Photoconductive UV Detectors were developed in the 1920s and ionizing Radiation Detectors were created in the 1940s. However, these devices encountered restricted usage owing to the limitations of natural diamonds. Specifically, these limitations were the small size and lack of control of the material characteristics. Recent advances in the high quality growth of diamond by chemical vapor deposition have created the opportunity for the application of this material in practical Detectors.