Determination of the nuclear level densities and radiative strength function for 43 nuclei in the mass interval 28≤A≤200

¹ University of Novi Sad, Faculty of Science, Department of Physics, Trg Dositeja Obradovica 3, 21000 Novi Sad, Serbia
² Joint Institute for Nuclear Research, 141980 Moscow region, Dubna, Russia
³ Technische Universität München, Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Lichtenbergstr. 1, 85747 Garching, Germany
⁴ European Commission, Joint Research Centre, Directorate G - Nuclear Safety and Security, Unit G.2, Retieseweg 111, 2440 Geel, Belgium
⁵ Institute of Physics Belgrade, Pregrevica 118, 11080 Zemun, Serbia

^* e-mail: nikola.jovancevic@df.uns.ac.rs

Published online: 6 March 2018

Abstract

The determination of nuclear level densities and radiative strength functions is one of the most important tasks in low-energy nuclear physics. Accurate experimental values of these parameters are critical for the study of the fundamental properties of nuclear structure. The step-like structure in the dependence of the level densities p on the excitation energy of nuclei E_ex is observed in the two-step gamma cascade measurements for nuclei in the 28 ≤ A ≤ 200 mass region. This characteristic structure can be explained only if a co-existence of quasi-particles and phonons, as well as their interaction in a nucleus, are taken into account in the process of gamma-decay. Here we present a new improvement to the Dubna practical model for the determination of nuclear level densities and radiative strength functions. The new practical model guarantees a good description of the available intensities of the two step gamma cascades, comparable to the experimental data accuracy.