Application of a single crystal chemical vapor deposition diamond detector for deuteron plasma neutron measurement

A single crystal chemical vapor deposition (scCVD) diamond detector has been characterized and employed for the neutron measurement at the HL-2A tokamak device. The scCVD diamond detector has been deposited with 5 μm of lithium fluoride (LiF) layer to enhance the sensitivity to thermal neutrons. Time stability of the detector has been studied with α-source and good performance has been found for more than 12 h. Neutron irradiations have been performed in four quasi-monoenergetic neutron fields in the energy range from 2.50 MeV to 16.03 MeV. The measured response function of the scCVD diamond detector to 14.13 MeV neutrons shows a narrow ¹²C (n, α)⁹Be reaction peak which is well isolated from other structures by about 1 MeV in energy, indicating the great potential as a fast neutron spectrometer. Neutron measurement of deuterium plasma discharge was established at the HL-2A tokamak device, and good consistence has been revealed among this detector signal and other related signals. - Highlights: • Operational parameters have been optimized by α-source tests in terms of energy resolution and time stability. • The detector has been characterized with quasi-monoenergetic neutron sources with energies ranging from 2.50 MeV to 16.03 MeV. • Time evolution of the neutron yield at HL-2A tokamak plasma discharge has been assessed with the scCVD diamond detector