INTERNAL EXCITATION OF INTERMEDIATE-MASS FRAGMENTS FROM COLLISIONS OFAR-36+AG NUCLEI AT 35 MEV NUCLEON/

Population ratios for neutron-unbound states compared to bound states were determined for intermediate mass fragments from Ar-36 + Ag collis ions at 35 MeV/nucleon. The population ratios were measured as a funct ion of fragment kinetic energy at angles of 15 degrees, 30 degrees, 45 degrees, and 60 degrees, especially for B-12 fragments but also for L i-7, Li-8, Be-11, and C-13 fragments. The results show no major depend ence on either the kinetic energy or the emission angle of the fragmen ts. There are signs of a moderate contribution to the dominating stati stical decay from nonequilibrium quasielastic decay at the smaller ang les. The population ratios for the different fragments are consistent with emission from a source of a single temperature which emits comple x nuclei at freeze-out. Comparision of the present results with those from a similar experiment, but with N-14 projectiles at 35 MeV/nucleon , shows that the population ratios for strongly damped processes are t he same for both N-14 and Ar-36 projectiles on Ag.