Fabrication of a single-crystal diamond neutron detector and its application in 14.1 MeV neutron detection in deuterium–tritium fusion experiments

A single-crystal diamond detector is fabricated to diagnose 14.1 MeV deuterium–tritium (D-T) fusion neutrons. The size of its diamond film is 4.5 mm × 4.5 mm × 500 μm. This film is sandwiched by a flat, strip-patterned gold electrode. The dark current of this detector is experimentally measured to be lower than 0.1 nA under an electric field of 30 kV cm⁻¹. This diamond detector is used to measure D-T fusion neutrons with a flux of about 7.5 × 10⁵ s^–1 cm^–2. The pronounced peak with a central energy of 8.28 MeV characterizing the ^12 \mathrmC(\mathrmn, \alpha) ^9 \mathrmBe reaction in the neutron energy spectrum is experimentally diagnosed, and the energy resolution is better than 1.69%, which is the best result reported so far using a diamond detector. A clear peak with a central energy of 6.52 MeV characterizing the ^12 \mathrmC\left(\mathrmn, \mathrmn^\prime\right) 3 \alpha reaction is also identified with an energy resolution of better than 7.67%.