Study of a radiator degrader CR39 based neutron spectrometer

The paper describes the experimental characterization of a neutron spectrometer based on a CR39 SSNTD coupled to a polyethylene radiator and an aluminium degrader. The response function of the spectrometer is calculated by using two analytical codes. The first one, written in Labview, permits to evaluate the critical angle of a particle (proton, alpha or recoil nucleus) impinging on the detector surface, as a function of the particle energy. The second code, written in Mathcad, calculates the recoil proton distribution generated by a monoenergetic neutron beam impinging on the polyethylene converter. The simulation software also accounts for the self radiator effect due to the recoil protons and to the oxygen and carbon recoil nuclei. The calculated response functions are compared with experimental data showing a fairly good agreement. Also the experimental reproducibility is satisfactory.