Silicon carbide neutron detector testing at the JSI TRIGA reactor for enhanced border and port security

In 2016, the NATO Science for Peace and Security Programme funded research project "Engineering SiliconCarbide for Border and Port Security" — E-SiCure was launched, its objective being the development ofradiation-hard silicon carbide (SiC) based detectors of special nuclear materials (SNM), with the aim to enhanceborder and port security barriers. Detector prototypes based on SiC Schottky Barrier Diodes (SBDs) and neutronconverter films were developed. This paper presents the results of a dedicated experimental testing campaignperformed at the Jožef Stefan Institute (JSI) TRIGA reactor in which several SiC detector prototypes equippedwith10B and6LiF converter films were irradiated in the Dry Chamber of the reactor. The obtained resultsdemonstrate a clearly measurable neutron response, which varies linearly with the neutron flux. The measuredparticle spectra from the SiC detectors exhibit a clear structure, attributable to the nature and energy ofsecondary particles originating as reaction products from nuclear reactions involving10B and6Li isotopes.The determined sensitivity of the detectors, their active volume being 1 mm×1 mm×25μm, 1 mm×1 mm×69μmand 1 mm×1 mm×170μm, was of the order of 2×10−5counts per second, per unit ofneutron flux [counts s−1per n cm−2s−1] (for neutron energies between 0 and 5 eV). Scaling the detectionsensitivity by a factor of105, i.e. to an array with a surface of around 20 cm×2 m, comparable to largeBF3or3He detectors, would theoretically enable an overall sensitivity of around 2 counts s−1per n cm−2s−1,which is already comparable to typical neutron sensitivity values of gas detectors, in the range from severalto over 100 counts s−1per n cm−2s−1. Due to its outstanding tolerance to harsh environments (including hightemperatures and radiation fields) and superior electronic properties when compared to other semiconductors,SiC is a promising base material for the fabrication of solid-state detectors with stable and long life-time.Improvements in sensitivity combined with the capability of fabricating large modules (SiC arrays), couldmake SiC an important detection technology, applicable also in the context of border and port security barriermonitoring