Monte Carlo calculation of neutron evaporation; excitation energy dependence of nuclear level density

Abstract

Experimental excitation function data in the heavy element region have been analyzed by a Monte Carlo technique to investigate the dependence of the nuclear level density on excitation energy. The analysis supports the prediction of the completely degenerate Fermi gas model that the nuclear temperature varies as the square root of the excitation energy. The value of the level density parameter a deduced from the experimental data is changed significantly when shell and pairing effects are taken into account by displacement of the characteristic energy surface from which the excitation energy is measured.