Mitja Majerle

At the NPI in Rez, the p + Be source reaction was investigated for 30 MeV proton beam and thick beryllium target. For neutron field determination of the p(30)+Be source reaction in close source-to-sample distance, the multi-foil activation technique with a set of 10 activation materials (Au, Co, Lu, Ti, In, Al, Y, Fe, Ni, Nb) was utilized. From resulting reaction rates, the neutron spectrum was reconstructed using the SAND-II unfolding code. New neutron field of white spectrum up to 28 MeV has an intensity of 8.6 × 1010 cm−2s−1 close to target. The obtained neutron field extends the utilization of cyclotron-based fast neutron sources at the NPI and provides new experimental opportunities for future irradiation experiments such as fast neutron activation analysis, nuclear data validation, and radiation damage study of electronics and materials for nuclear energetics.

New experimental data on the peak neutron production in the ⁷Li(p,n) reaction were collected during several irradiation campaigns at the NPI CAS. Time-of-flight method was used to measure the number of the peak neutrons in the forward direction, and the number of produced ⁷Be nuclei was determined using γ-spectrometry. The new measurement results are compared with experimental data from the literature and used for the validation of several different systematics and nuclear data libraries developed over the years.