FORMATION OF 7Be IN NUCLEAR REACTIONS INDUCED BY 85-MeV PROTONS

Cross sections were measured for the formation of 7Be in targets bombarded with 85-MeV protons. The variation of these cross sections with the mass and neutron-to-proton ratio of the target was investigated.Cross-section calculations were performed on the assumption that 7Be is emitted from the irradiated target as an evaporated particle. Calculated and measured cross sections were in good agreement for medium and heavy targets (A > 55). The calculation underestimated the production of' 7Be in light targets (27 < A < 55).

INTERACTION OF VANADIUM WITH PROTONS OF ENERGIES UP TO 84 MEV

Radiochemical techniques have been used to determine absolute excitation functions for 17 nuclides formed as spallation products from the irradiation of vanadium by protons of energy up to 84 Mev. The shape of the excitation functions and classical threshold calculations showed evidence of contribution of heavy-particle emission in the reactions of the type (p,3pxn), (p,5pxn), and (p,7pxn). The Barr method for analysis of the cross-section distribution was modified and applied at 60 and 80 Mev bombarding energies. The experimentally measured cross sections for 16 nuclides at 60 and 80 Mev bombarding energies were fitted to the four-parameter Rudstam equation σ (A,Z) = exp [PA−Q−R(Z−SA)2]. Comparison of the results obtained at 8 Mev bombarding energy with the predictions of the weak and strong absorption models showed better agreement with the predictions obtained by using the surface absorption Fernbach–Bjorklund potential.