Nuclear level densities from particle spectra

This paper demonstrates the utility of high energy particle spectra in low energy heavy ion reactions for the measurements of nuclear level density. From the measurements of high energy proton spectra in various heavy ion reactions, the energy dependence of total NLD in different nuclei has been extracted over a wide excitation energy range. Different behaviours of the energy dependence of the NLD parameter α in these nuclei are directly demonstrated from a suitable representation of the experimental data and are related with the shell-correction terms. The multiplicity gated measurements establish that the conventional description of the J-dependence does not work well. Finally an unusual feature of a bump in the fold gated spectra is observed in the data. Although some speculations are made regarding the J-dependence of the NLD in order to describe the data, the observations remain to be understood from a rigorous theoretical consideration