Inclusive proton production cross sections in (d,xp) reactions induced by 100 MeV deuterons - art. no. 014610

Energy spectra and angular distributions of protons emitted from the inclus ive (d,.xp) reaction on Be-9, C-12, Al-27 Ni-58, Nb-93. Ta-181, Pb-208, and U-238 were measured at an incident deuteron energy of 100 MeV. The protons were detected at laboratory scattering angles of 6 degrees to 120 degrees and 8 degrees to 120 degrees for the targets with 9 less than or equal toA less than or equal to 27 and A greater than or equal to 58. respectively. T wo triple-element and three double-element detector telescopes allowed for a low energy detection threshold of 4 to 8 MeV. The experimental results ar e presented in double-differential as well as angle- and energy-integrated cross sections. For all the nuclei studied, the energy spectra at forward a ngles show pronounced deuteron breakup peaks centered around approximately half of the incident deuteron energy. Qualitatively the energy spectra are similar for all nuclei at a given angle except in the region of the low-ene rgy evaporation peak. As a function of target mass the evaporation cross se ctions are found to increase up to A = 58 after which they decrease again. The total preequilibrium proton cross section is roughly (280 +/- 60)A(1/3) mb. The angular distributions at the high emission energies are strongly f orward peaked while the distributions of the low-energy protons are almost isotropic. The LAHET code system (LCS) was applied to calculate the proton production cross sections. Standard LCS calculations are found to underpred ict the experimental cross sections at the very forward angles on the heavy target nuclei (A greater than or similar to 58). By adding incoherently th e Coulomb breakup cross section of the deuteron to the LCS calculations the experimental cross sections are reproduced to within 10%. Although preequi librium processes are a necessary ingredient in the LCS calculations of the large-angle cross sections, this code still fails to predict the experimen tal evaporation distributions.