Comparison of light- and heavy-ion emission from theC12+O16system

Abstract

Excitation functions of the total proton and ..cap alpha..-particle yields from the /sup 12/C+/sup 16/O reaction have been measured in the range E/sub c.m./=12.9 to 27.4 MeV, with angular distribution measurements at E/sub c.m./=14.9, 21, and 26.6 MeV. For comparison, the elemental distribution of evaporation residues was also measured at the latter three energies. The ..cap alpha.. excitation curve exhibits structure corresponding to the oscillations seen in an earlier measurement of the total fusion cross section, while the proton cross section increases rather smoothly with energy. At 15 MeV all the proton and ..cap alpha.. cross section is accounted for by the observed evaporation residues, but an increasing excess of light-ion production is seen at the higher energies. The excess cross section, if interpreted as 3..cap alpha.. production, compensates for the previously observed decrease in fusion cross section below the expected total reaction cross section.