Neutron and Gamma Ray Dosimetry in Spent-Fuel Radiation Environments Using Silicon Carbide Semiconductor Radiation Detectors

ABSTRACTThis paper describes the fabrication of mercuric iodide nuclear radiation detectors suitable for X and gamma ray spectrometry at room temperature. The active area of the detectors studied are between 0.2 and 1.5cm sq and they are up to 0.5mm thick. The method of producing a stable electrical contact to the crystal using sputtered germanium has been studied. The X-ray resolution of a 1.5cm sq. area detector at 32 keV is 2.3 keV FWHM when operated at room temperature in conjunction with a time variant filter amplifier. A factor which is important in the fabrication of the detector is the surface passivation necessary to achieve a useful detector life.This type of detector has been used on a wavelength dispersive X-ray spectrometer for energy measurements between 10 and 100 keV. The advantages over the scintillation counter, more commonly used, is the improved resolution of the HgI2 detector and its smaller size. The analyser is primarily used for the detection of low levels of heavy metals on particulate filters. The detectors have also been used on an experimental basis for gamma ray backscatter measurements in the medical field.

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Diffusion Length in n-Doped 4H Silicon Carbide Crystals Detected by Alpha Particle Probe

Materials Science Forum ◽

10.4028/www.scientific.net/msf.615-617.857 ◽

2009 ◽

Vol 615-617 ◽

pp. 857-860

Author(s):

Donatella Puglisi ◽

Gaetano Foti ◽

Giuseppe Bertuccio

Keyword(s):

Silicon Carbide ◽

Doping Concentration ◽

Diffusion Length ◽

Schottky Diodes ◽

Radiation Detectors ◽

Electron Hole ◽

Active Volume ◽

Particle Detectors ◽

Electron Hole Pair ◽

Nuclear Detectors

The achievement of nuclear detectors in Silicon Carbide imposes severe constraints on the electronic quality and thickness of the material due to the relatively high value of the energy required to generate an electron-hole pair (7.8 eV) in this material compared to the value for Si (3.6 eV). In this work, 4H-SiC charged particle detectors were realised using epitaxial layers of n-type doping as active region. The thickness of the epilayer is always below 80 μm with a net doping concentration in the range of 8 x 1013 to 1016 cm-3. These properties allowed the fabrication of Schottky diodes that operate well as radiation detectors. At low doping concentration, the epilayer is totally depleted at quite low reverse bias (≈ 50 V), thereby obtaining the maximum active volume.

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Silicon Carbide Radiation Detectors: Progress, Limitations and Future Directions

MRS Proceedings ◽

10.1557/opl.2013.1142 ◽

2013 ◽

Vol 1576 ◽

Cited By ~ 2

Author(s):

Frank H. Ruddy

Keyword(s):

Silicon Carbide ◽

Rapid Development ◽

Chemical Vapor ◽

Radiation Detectors ◽

Neutron Detectors ◽

Future Directions ◽

Materials Development ◽

Late Twentieth ◽

Manufacturing Techniques ◽

Further Development

ABSTRACTSilicon carbide has long been a promising material for semiconductor applications in high-temperature environments. Although silicon carbide radiation detectors were demonstrated more than a half century ago, the unavailability of high-quality materials and device manufacturing techniques hindered further development until about twenty years ago. In the late twentieth century, the development of advanced SiC crystal growth and epitaxial chemical vapor deposition methods spurred rapid development of silicon carbide charged particle, X-ray and neutron detectors. The history and status of silicon carbide radiation detectors as well as the influence of materials and device packaging limitations on future detector development will be discussed. Specific silicon carbide materials development needs will be identified.

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Microhardness study of CdZnTeSe crystals for X-ray and gamma ray radiation detectors

2019 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC) ◽

10.1109/nss/mic42101.2019.9059851 ◽

2019 ◽

Author(s):

P. Moravec ◽

J. Franc ◽

V. Dedic ◽

P. Minarik ◽

H. Elhadidy ◽

...

Keyword(s):

Gamma Ray ◽

Radiation Detectors ◽

Microhardness Study ◽

X Ray

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Tripoli-4 Gamma-Ray Dose Calculation for Spent PWR Fuels

Volume 1: Plant Operations, Maintenance, Engineering, Modifications, Life Cycle and Balance of Plant; Nuclear Fuel and Materials; Radiation Protection and Nuclear Technology Applications ◽

10.1115/icone21-15498 ◽

2013 ◽

Author(s):

Yi-Kang Lee ◽

Kabir Sharma

Keyword(s):

Gamma Ray ◽

Dose Calculation ◽

Radiation Shielding ◽

Pressurized Water Reactor ◽

Spent Fuel ◽

Pressurized Water ◽

Heterogeneous Model ◽

Transport Code ◽

Fuel Pin ◽

Monte Carlo Transport

The gamma-ray dose calculation is essential for the radiation shielding of pressurized water reactor (PWR) spent fuels. Homogenization modeling of fuel pin lattices for typical PWR spent fuel pins is regularly applied on the radiation protection calculation of gamma-ray dose in an air medium. However, depending on the size of the homogenized lattice and the location of the detectors, under-estimation or over-estimation of the gamma-ray dose due to the homogenization modeling can be obtained with respect to the detailed heterogeneous model. In previous published results from MCNP-4A and 4C calculations on gamma-ray dose from spent PWR fuel pins, very different homogeneous to heterogeneous (Hom/Het) ratios were reported. In this study these Hom/Het ratios have been re-evaluated and benchmarked by using the TRIPOLI-4 Monte Carlo transport code. The new TRIPOLI-4 mesh tally capabilities have also been applied to calculate the radial and axial gamma-ray dose distribution. With the recently upgraded TRIPOLI-4 display tool, the dose rate maps and the isodose rate curves around a spent PWR fuel assembly have been established.

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