Analytical model for a monolithic silicon telescope - Response function of the E stage

A monolithic silicon telescope coupled to a polyethylene radiator was studied and tested as a neutron spectrometer. The detector consists of a DE and an E stage detector, about 1.9 and 500 mm in thickness, respectively. The neutron spectra were derived from the measurement of the energy deposited in the E stage by recoil-protons generated in the radiator. The detectable energy range of the present detection system is about 0.350–8 MeV. In order to optimize the reconstruction of the impinging neutron spectra, an analytical model of the response functions of the detection system to mono-energetic neutrons was developed and implemented in an unfolding procedure. The model is based on the kinematics of neutron elastic scattering on hydrogen and takes into account the actual geometrical structure of the silicon telescope. The calculated response functions were compared with the results of Monte Carlo simulations (by using the FLUKA code) and those obtained by an experimental characterization.