Characteristics of Fabricated Neutron Detectors Based on a SiC Semiconductor

Abstract

Wide-band-gap semiconductors such as SiC, AlN, and GaN are promising materials for harsh environment applications due to their high-temperature operation capability. Two types of PIN-type semiconductor neutron detectors based on SiC were designed and fabricated for nuclear power plant (NPP) applications such an in-core reactor neutron flux monitoring and safeguarding nuclear materials. One is for fast neutron detection and the other, which was evaporated with 6 LiF, is for thermal neutron detection. In this study, preliminary tests, such as the determination of I-V and alpha responses, were performed. Reaction probabilities with respect to neutron energies were also calculated by using an MCNPX code for comparison with the experimental results. Responses of the neutrons were measured at the Ex-core Neutron irradiation Facility (ENF) of the High-flux Advanced Neutron Application Reactor (HANARO) research reactor at the Korea Atomic Energy Research Institute (KAERI). Pulse height spectra and count rates were measured with respect to the neutron fluxes from 1:6 Â 10 6 n/cm 2 Ás to 1:9 Â 10 7 n/cm 2 Ás. Also, a 0.99 root-mean-square value of linearity against the fluxes to the count rates was obtained with the fabricated neutron detectors. For a thermal neutron detector, a 3.3% detection efficiency was obtained.

Effect of metal electrode on characteristics of gamma-irradiated silicon carbide detector

“…The detector with the Cr/Au electrode shows the lowest leakage current and that with the Ti/Au electrode the highest over the entire voltage range. The leakage current of Ni/Au electrode detector is 0.24 μA at −100 V, which is in good agreement with the data from our previous research [16]. Figure 3 shows the leakage currents of the three irradiated SiC detectors.…”

4H-SiC Schottky Barrier Diodes for Efficient Thermal Neutron Detection

“…We have reached the highest reported efficiency [13][14][15]21,22] for the 4H-SiC-based neutron detector of almost 5% for the thermal neutrons.…”

“…The neutron detection efficiency limitation is a consequence of reaction product self-absorption. Maximum reported efficiency for the single-coated detectors is 5% for the thermal neutrons [13][14][15][21][22][23]. 6 LiF and 10 B 4 C converter layers with normalized surface area of three different detector sizes (1 mm × 1 mm, 2 mm × 2 mm, and 3 mm × 3 mm).…”

“…The neutron detection efficiency limitation is a consequence of reaction product self-absorption. Maximum reported efficiency for the single-coated detectors is 5% for the thermal neutrons [13][14][15][21][22][23].…”

“…The thickness of the neutron converter plays a crucial role in the detector efficiency. The maximum achievable efficiency, for detectors with single converter film positioned in front of the detector, peaks at 4.4% for the 6 LiF converter film and 4% for the 10 B converter film [13][14][15]. Elemental 6 Li offers the highest achievable efficiency of 11.5%, but it is readily avoided because of its reactivity and flammability, among other properties.…”