Verification of Models for Calculation of E1 Radiative Strength

TL;DR

This paper evaluates existing models for dipole radiative strength functions by comparing calculated photoabsorption and gamma-decay data with experiments, proposing simplified models and providing new GDR parameters for better estimates.

Contribution

It introduces simplified Lorentzian models, provides new GDR parameters, and assesses the applicability of phenomenological and microscopic models for dipole RSF estimation.

Findings

Simplified Lorentzian models are effective for energy up to 20 MeV.

Phenomenological models work well with known GDR parameters.

Microscopic and semi-classical models are more suitable when GDR parameters are unknown.

Abstract

Photoabsorption cross sections and gamma-decay strength function are calculated and compared with experimental data to test the existing models of dipole radiative strength functions (RSF) for the middle-weight and heavy atomic nuclei. Simplified version of the modified Lorentzian model are proposed. New tables of giant dipole resonance (GDR) parameters are given. It is shown that the phenomenological closed-form models with asymmetric shape can be used for overall estimates of the dipole RSF in the gamma -ray energy region up to about 20 MeV when GDR parameters are known or the GDR systematics can be adopted. Otherwise, the HFB-QRPA microscopic model and the semi-classical approach with moving surface appear to be more adequate methods to estimate the dipole photoabsorption RSF.