PROBING REACTION DYNAMICS WITH THE PT-196(N,XN GAMMA) REACTIONS FOR X-LESS-THAN-OR-EQUAL-TO-15

Discrete gamma-ray spectra have been measured as a function of inciden t neutron energy for nuclei produced in the Pt-196(n,xn gamma) reactio ns. Spectroscopy was done using the large-scale Compton suppressed Ge gamma-ray spectrometer GEANIE. The ''white'' source neutron beam was p roduced at the Los Alamos Neutron Science WNR facility. Reaction neutr on energy was determined using the time-of-flight technique. Reaction- channel yields were inferred from the measured intensity sum of the 2( 1)(+) --> 0(1)(+) and the 2(2)(+) --> 0(1)(+) transitions for the Pt-1 96(n,xn) reactions for x less than or equal to 15. Weisskopf-Ewing cal culations (including precompound) done with the HMS-ALICE code correct ly predict the bulk of the (n,xn) reaction products for low multiplici ty. However, they do not accurately predict yield ratios of the differ ent (n,xn) reactions for x greater than or equal to 9. In addition, th ere is no consistent experimental indication of charged-particle react ion channels (n,pxn) for incident neutron energies above 60 MeV where they are predicted to account for approximately 1/3 of the total react ion cross section. Several possible causes are discussed for these dis crepancies. Finally, the region of E-J phase space populated in this r eaction is probed for several of the strongest reaction channels throu gh the observation of relative yields for different yrast and off-yras t states.