A ray-trace-type counter telescope for neutron spectrometry

A compact recoil-proton counter telescope with two position sensitive proportional counters (PSPCs) for neutron spectrometry has been developed. This counter telescope consists of a radiator (a thin polyethylene film), two PSPCs used as ΔE detector, and an Si-SSD used as E detector. Using the position information extracted from two PSPCs, the three-dimensional trajectory of the recoil proton and the recoil angle can be determined event by event. The performance of this counter telescope was tested by the measurement of 7.2-MeV neutrons produced from D-D reactions. It was shown that the energy spectra of neutrons could be obtained by determining the energy of each incident neutron using a recoil angle.