Fusion neutron diagnostics with CVD diamond detectors

Abstract

The measurement of Deuterium–Deuterium (DD) and Deuterium–Tritium (DT)-fusion neutrons is crucial for plasma diagnostics at nuclear fusion facilities, such as ITER. Elevated temperatures and high radiation levels challenge radiation detectors. Chemical Vapour Deposition (CVD) diamond withstands harsh environments and is a distinguished candidate for reliable plasma instrumentation (Angelone et al., 2021 and Passeri et al., 2021). Neutron-induced nuclear reactions on Carbon nuclei of diamond substrates are the basis for fusion neutron detection with CVD diamond detectors. DD-fusion neutrons have an energy of 2.45 MeV. The corresponding response function of diamond sensors is purely elastic scattering and has a characteristic shape. DT-fusion neutrons have 14.1 MeV kinetic energy, and their response function reveals different nuclear reactions. The 12C(n, α)9Be peak is the most prominent structure in this response function. The principles of neutron diagnostics with CVD diamond detectors are discussed in this paper and the measured response functions of diamond sensors for 2.45 MeV and 14.1 MeV neutrons are presented, as well as the fusion neutron measurement using a proton-recoil telescope.