A Neutron Spectrometer with High Spatial Resolution for the Characterization of Mixed Fast Neutron Fields

摘要

A recoil-proton neutron spectrometer with high spatial and energy resolution intended for the characterization of mixed neutron fields around accelerators, in the range 0.3-8 MeV, is presented. The neutron converter is a 1 mm thick polyethylene foil and the recoil proton detector is a 500 mum thick monolithic silicon DeltaE/E telescope. In order to reject the low LET events, recoil protons are triggered by the signal of the 2 mum thick DeltaE stage and further off-line discriminated by means of the DeltaE/E scatter plot. The spectrometer has been irradiated with monoenergetic and continuous neutron fields at the CN Van De Graaff accelerator of INFN Legnaro Nat. Lab. (Padua). Results are in good agreement with TOF references in the range 0.35-3 MeV.