Neutron and gamma performance testing of silicon carbide semiconductor detectors

Abstract

BackgroundDetectors based on the third-generation semiconductor material silicon carbide (SiC) offer several important advantages, such as compactness, faster charge-collection times, and easier n/γ identification, and they are widely used in reactor core dose monitoring.PurposeIn this study, the n/γ signal amplitude, neutron fluence rate, and linear response calibration performances were tested systematically for a self-developed third-generation SiC semiconductor detector.MethodsFirstly, the neutron conversion layer material 6LiF (with a 95% abundance of 6Li) was sprayed onto a SiC substrate using electron beam evaporation vacuum coating technology to achieve the optimized thickness of 25 μm for the self-developed third-generation SiC semiconductor detector. Then, 241Am α radioactive source (activity 9.37×103 Bq) was used to observe α particle response signal amplitude, and γ response testing of radiation was conducted in the 137Cs γ source (activity 6.23×107 Bq) environment. In addition, the SiC detector's neutron flux response linearity, γ dose rate response linearity and calibration of neutron fluence rate response linearity were measured in the standard radiation field systems.ResultsThe measurement results show that the SiC semiconductor detector has a linear fit of R² = 0.996 9 in the neutron fluence rate range of 1×103~1×106 cm-2∙s-1, with a good linear response, and the response range of the neutron/gamma dose is 0.005~20 Gy∙h-1.ConclusionThe SiC detectors with such good n/γ performance can be used for real-time and accurate monitoring of neutron and gamma doses in nuclear power field reactors.

Keywords

• sic detector
• neutron fluence rate
• gamma dose
• linear responses