Response function measurements of the Self-TOF neutron detector for neutrons up to 800 MeV

The Self-TOF detector has been developed for high energy neutron spectromet ry behind a shield. This detector consists of a radiator, a start counter a nd a stop counter. The radiator is composed of 20 thin plastic-scintillatio n detectors and the stop counter is segmented into nine plastic-scintillati on detectors. The response functions of the SeIf-TOF detector for high ener gy neutrons up to 800 MeV were measured at the HIMAC (Heavy Ion Medical Acc elerator in Chiba) of the National Institute of Radiological Sciences (NIRS ). The measured responses were compared with those calculated using the LCS (LAHET Code System). The LCS results considerably overestimate the measure mental results with an increase in the neutron energy. It was found that th is detector can give the neutron energy spectrum by using the FERDO-U unfol ding code combined with the measured response functions, and is useful for high energy neutron spectrometry because of the almost constant efficiency for neutrons above 100 MeV.