A New Fast Neutron Spectrometer Made of Epitaxial Integrated dE-E Si Detector

A fast neutron spectrometer by recoil proton detection method was developed. The spectrometer is consisted of a radiator and an integrated dE-E Si detector, in which an epitaxial dE counter of less than 10 ?m and an E counter are incorporated. Recoil protons from the radiator can easily be identified from ? ray background; and besides each recoil proton angle can be determined by the dE and E counter outputs. and thus an unfolded neutron spectrum can be attained. Neutron detection efficiency is high, compared with conventional dE-E telescope spectrometers, owing to the wide solid angle coverage of recoil protons. The basic characterestics and measured neutron spectra are described.