Experimental investigation on the temperature dependence of the nuclear level density parameter

TL;DR

This study investigates how temperature and angular momentum influence the nuclear level density parameter in $^{97}$Tc, revealing that the parameter decreases with angular momentum and showing agreement with certain theories at high J.

Contribution

It provides experimental data on the temperature and angular momentum dependence of the nuclear level density parameter, comparing results with theoretical models including FTBCS1.

Findings

k decreases with increasing J at all energies

Experimental data agree with FTBCS1 at high J

Deviations observed at low J from all models

Abstract

The effect of temperature (T) and angular momentum (J) on the inverse level density parameter (k) has been studied by populating the compound nucleus $^{97}$Tc in the reaction $^{4}$He + $^{93}$Nb at four incident beam energies of 28, 35, 42 and 50 MeV. For all the four energies, the value of k decreases with increasing J. The T dependence of k has been compared for two angular momentum windows with different theoretical predictions as well as with FTBCS1 calculation which takes into account the quasiparticle-number fluctuations in the pairing field. Interestingly, the experimental data are in good agreement with the theoretical calculations at higher J but deviate from all the calculations at lower J.