SILICON CARBIDE NEUTRON DETECTOR PROTOTYPE TESTING AT THE JSI TRIGA REACTOR FOR ENHANCED BORDER AND PORTS SECURITY

¹ Jožef Stefan Institute, Slovenia
² Ruđer Bošković Institute, Croatia
³ Australian Nuclear Science and Technology Organisation, Australia
⁴ National Institutes for Quantum and Radiological Science and Technology, Japan
⁵ University of Aveiro, Portugal
⁶ University of Ljubljana, Slovenia

Published online: 22 February 2021

Abstract

In 2016, the “E-SiCure” project (standing for “Engineering Silicon Carbide for Border and Port Security”), funded by the NATO Science for Peace and Security Programme was launched. The main objective is to combine theoretical, experimental and applied research towards the development of radiation-hard SiC-based detectors of special nuclear materials (SNM), with the end goal to enhance border and port security barriers. Prototype neutron detectors, configured as 4H-SiC-based Schottky barrier diodes, were developed for the detection of secondary charged particles (tritons, alphas and lithium atoms) which are the result of thermal neutron reactions on ¹⁰B and ⁶LiF layers above the surface of the 4H-SiC diodes. We designed a stand-alone prototype detection system, consisting of a preamplifier, shaping amplifier and a multichannel analyser operated by a laptop computer, for testing of neutron detector prototypes at the Jožef Stefan Institute (JSI) TRIGA reactor using a broad beam of reactor neutrons. The reverse bias for the detector diode and the power to electronic system were provided by a standalone battery-powered voltage source. The detector functionality was established through measurements using an ²⁴¹Am alpha particle source. Two dedicated experimental campaigns were performed at the JSI TRIGA reactor. The registered pulse height spectra from the detectors, using both ¹⁰B and ⁶LiF neutron converting layers, clearly demonstrated the neutron detection abilities of the SiC detector prototypes. The computed neutron detection sensitivity of the single prototype detectors demonstrates that scaling SiC detectors into larger arrays, of dimensions relevant for border and port radiation detectors, could enable neutron sensitivity levels matching gas-based detector technology.