Measurement and analysis of neutron spectra from thick targets of Al and Ti bombarded by 30–50 MeV α particles

Energy distributions of neutrons emitted from thick targets of ²⁷Al and ⁴⁶Ti are measured for alpha induced reactions at 30, 40, and 50 MeV projectile energies. Measurements are done at 0°,30°, and 45° with respect to the projectile direction using the proton recoil scintillation technique. The measured data are compared with results from calculations using three different approaches of the exciton model namely, the master equation, the closed form and the hybrid model (a variant of the exciton model). The corresponding nuclear reaction model codes used for the purpose are PEQAG [E. Betak and J. Dobes, Report No. IP EPRC SAS 43/(1983), Bratislava, 1983], PRECO-D2, [C. Kalbach, Report No. LA-10248-MS, Los Alamos National Laboratory, Los Alamos, 1985] and ALICE91 [M. Blann, Lawrence Livermore National Laboratory Report No. UCID 19614, 1982], respectively. Proton induced neutron yield distributions measured by others are also included in the comparison. The calculated results from the hybrid model code ALICE91 give overall close approximations of the measured data compared to the other models.