A tool for calculation of 7Li(p,n)7Be neutron source spectra below the three-body break-up reaction threshold

We developed a new deterministic neutron source spectrum code EPEN - Energy of Proton Energy of Neutron - for a given lithium target thickness, sample angular coverage and proton energy from the reaction threshold to the three-body break-up threshold. The angular differential cross sections of the 7 Li(p,n 0 ) 7 Be and 7 Li(p,n 1 ) 7 Be reactions evaluated by Liskien and Paulsen were adopted above 1.95 MeV while the functional form suggested by Macklin and Gibbons was adopted for the 7 Li(p,n 0 ) 7 Be reaction cross section near threshold. The spectra obtained by EPEN are validated by the experimental spectra and also compared with the spectra predicted by two Monte Carlo codes, SimLiT and PINO. The results of comparison are discussed in detail.