Study of inclusive proton spectra from low energy deuteron reactions in terms of spectator break-up and coulomb dissociation of the projectile

Abstract

Two silicon detectors were used to measure continuous proton spectra at lab angles from 23° to 170° resulting from deuteron-induced reactions on the targets 27Al, 62Ni, 93Nb, 119Sn, 181Ta and 232Th at 15 MeV bombarding energy. Compared with previous work at higher bombarding energies new phenomena appear for the heavier targets ( A > 93) where the incoming energy is near to the Coulomb barrier. At energies at about the maximum of the break-up bump of the (spectator) proton the DWBA break-up theory predicts an angular separation of the elastic and inelastic modes consistent with the experiment. However, at lower energies this theory underestimates the observed cross sections by factors of 10 to 100. It is found that the Coulomb dissociation of the deuteron can account for this deficiency. Together with a re-analysis of previous experimental data of 25.5 MeV and 24.7 MeV the mass and energy dependence of the deuteron break-up process is discussed. A systematics of the total (d, p) yields to bound states reveals that the involved neutron transfer reaction in good approximation is proportional to the inelastic break-up yield at threshold.