Improvement of the low-energy limit of a silicon-based neutron spectrometer

To improve the low energy limit of a recoil-proton neutron spectrometer based on silicon diodes, better discrimination against low LET events has been addressed. The signal from a thin diode interposed between the radiator and the main detector has been used as the coincidence gate for the recoil protons and gamma field background has been completely rejected. A silicon monolithic telescope provides the thin diode (Delta E stage) and the main detector (E stage). Irradiation tests with monoenergetic neutrons have supplied the response functions that well fit the results of MC simulations. The minimum detectable energy resulted to be about 100 keV.