Excitation Functions of (p, xp) Reactions

Abstract

Radiochemically measured excitation functions are reported for several ($p, \mathrm{xp}$) reactions, where $x>~2$, for target nuclei encompassing a wide range of mass numbers and for incident energies of 100 to 440 MeV. The ($p, 2p$) reactions were studied using ${\mathrm{Si}}^{30}$, ${\mathrm{Zn}}^{68}$, and ${\mathrm{W}}^{186}$ as target nuclei; the ($p, 3p$) reactions were studied using ${\mathrm{Si}}^{30}$, ${\mathrm{P}}^{31}$, ${\mathrm{V}}^{51}$, ${\mathrm{As}}^{75}$, ${\mathrm{W}}^{186}$, and ${\mathrm{Re}}^{187}$; the ($p, 4p$) reactions were studied using ${\mathrm{P}}^{31}$, ${\mathrm{S}}^{32}$, ${\mathrm{As}}^{75}$, and ${\mathrm{Re}}^{187}$; and a ($p, 5p$) excitation function was measured using ${\mathrm{S}}^{32}$ as the target. The data do not seem to exclude important contributions by either the knock-on or evaporation mechanisms in all mass regions studied, although, according to qualitative arguments it seems plausible that knock-on processes predominate in the high-mass region.