Excitation Energy And Angular Momentum Dependence Of The Nuclear Level Density Parameter Around A Approximate To 110

Neutron kinetic energy spectra in coincidence with low-energy gamma-ray multiplicities have been measured around A approximate to 110 in the O-16 + Nb-93 and Ne-20 + Nb-93 reactions in a compound nuclear excitation energy range of approximate to 90-140 MeV. The excitation energy (temperature) dependence and the angular momentum (spin) dependence of the inverse level density parameter k have been investigated by comparing the experimental data with statistical Hauser-Feshbach calculations. In contrast to the available systematic in this mass region, the inverse level density parameter showed an appreciable increase as a function of the excitation energy. The extracted k values at different angular momentum regions, corresponding to different gamma multiplicities, also showed an overall increase with the average nuclear spins. The experimental results have been compared with a microscopic statistical-model calculation and found to be in reasonable agreement with the data. The results provide useful information to understand the variation of nuclear level density at high temperature and spins.