Development of a D–D neutron spectrum detector based on helium-3 proportional counter

Deuterium–deuterium (D–D) neutron spectrum diagnostics in tokamaks are a challenging task with current technologies. To address this issue, we designed and tested a fast and compact helium-3 proportional counter with a diameter of 2.5 cm and an effective length of 15 cm and using Kr as a stopping gas. The detector achieved a resolution of 96 keV for 2.406 MeV neutrons with a pulse shaping of 2 µs. Test results indicate that this detector has the potential to form a D–D neutron spectrometer for tokamaks, composed of detector arrays.