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Title: On microscopic theory of radiative nuclear reaction characteristics

Abstract

A survey of some results in the modern microscopic theory of properties of nuclear reactions with gamma rays is given. First of all, we discuss the impact of Phonon Coupling (PC) on the Photon Strength Function (PSF) because it represents the most natural physical source of additional strength found for Sn isotopes in recent experiments that could not be explained within the standard HFB + QRPA approach. The self-consistent version of the Extended Theory of Finite Fermi Systems in the Quasiparticle Time Blocking Approximation is applied. It uses the HFB mean field and includes both the QRPA and PC effects on the basis of the SLy4 Skyrme force. With our microscopic E1 PSFs, the following properties have been calculated for many stable and unstable even–even semi-magic Sn and Ni isotopes as well as for double-magic {sup 132}Sn and {sup 208}Pb using the reaction codes EMPIRE and TALYS with several Nuclear Level Density (NLD) models: (1) the neutron capture cross sections; (2) the corresponding neutron capture gamma spectra; (3) the average radiative widths of neutron resonances. In all the properties considered, the PC contribution turned out to be significant, as compared with the standard QRPA one, and necessary to explain themore » available experimental data. The results with the phenomenological so-called generalized superfluid NLD model turned out to be worse, on the whole, than those obtained with the microscopic HFB + combinatorial NLD model. The very topical question about the M1 resonance contribution to PSFs is also discussed.Finally, we also discuss the modern microscopic NLD models based on the self-consistent HFB method and show their relevance to explain the experimental data as compared with the phenomenological models. The use of these self-consistent microscopic approaches is of particular relevance for nuclear astrophysics, but also for the study of double-magic nuclei.« less

Authors:
 [1]; ;  [2];  [3]
  1. National Research Centre “Kurchatov Institute” (Russian Federation)
  2. Institute for Physics and Power Engineering (Russian Federation)
  3. Institut d’Astronomie et d’Astrophysique (Belgium)
Publication Date:
OSTI Identifier:
22612639
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Atomic Nuclei; Journal Volume: 79; Journal Issue: 4; Other Information: Copyright (c) 2016 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; CAPTURE; CROSS SECTIONS; ENERGY-LEVEL DENSITY; EXPERIMENTAL DATA; GAMMA RADIATION; GAMMA SPECTRA; LEAD 208; MAGIC NUCLEI; MEAN-FIELD THEORY; NEUTRON REACTIONS; NICKEL ISOTOPES; PHONONS; PHOTONS; RESONANCE; SKYRME POTENTIAL; STRENGTH FUNCTIONS; TIN 132

Citation Formats

Kamerdzhiev, S. P., Achakovskiy, O. I., E-mail: oachakovskiy@ippe.ru, Avdeenkov, A. V., and Goriely, S. On microscopic theory of radiative nuclear reaction characteristics. United States: N. p., 2016. Web. doi:10.1134/S106377881604013X.
Kamerdzhiev, S. P., Achakovskiy, O. I., E-mail: oachakovskiy@ippe.ru, Avdeenkov, A. V., & Goriely, S. On microscopic theory of radiative nuclear reaction characteristics. United States. doi:10.1134/S106377881604013X.
Kamerdzhiev, S. P., Achakovskiy, O. I., E-mail: oachakovskiy@ippe.ru, Avdeenkov, A. V., and Goriely, S. Fri . "On microscopic theory of radiative nuclear reaction characteristics". United States. doi:10.1134/S106377881604013X.
@article{osti_22612639,
title = {On microscopic theory of radiative nuclear reaction characteristics},
author = {Kamerdzhiev, S. P. and Achakovskiy, O. I., E-mail: oachakovskiy@ippe.ru and Avdeenkov, A. V. and Goriely, S.},
abstractNote = {A survey of some results in the modern microscopic theory of properties of nuclear reactions with gamma rays is given. First of all, we discuss the impact of Phonon Coupling (PC) on the Photon Strength Function (PSF) because it represents the most natural physical source of additional strength found for Sn isotopes in recent experiments that could not be explained within the standard HFB + QRPA approach. The self-consistent version of the Extended Theory of Finite Fermi Systems in the Quasiparticle Time Blocking Approximation is applied. It uses the HFB mean field and includes both the QRPA and PC effects on the basis of the SLy4 Skyrme force. With our microscopic E1 PSFs, the following properties have been calculated for many stable and unstable even–even semi-magic Sn and Ni isotopes as well as for double-magic {sup 132}Sn and {sup 208}Pb using the reaction codes EMPIRE and TALYS with several Nuclear Level Density (NLD) models: (1) the neutron capture cross sections; (2) the corresponding neutron capture gamma spectra; (3) the average radiative widths of neutron resonances. In all the properties considered, the PC contribution turned out to be significant, as compared with the standard QRPA one, and necessary to explain the available experimental data. The results with the phenomenological so-called generalized superfluid NLD model turned out to be worse, on the whole, than those obtained with the microscopic HFB + combinatorial NLD model. The very topical question about the M1 resonance contribution to PSFs is also discussed.Finally, we also discuss the modern microscopic NLD models based on the self-consistent HFB method and show their relevance to explain the experimental data as compared with the phenomenological models. The use of these self-consistent microscopic approaches is of particular relevance for nuclear astrophysics, but also for the study of double-magic nuclei.},
doi = {10.1134/S106377881604013X},
journal = {Physics of Atomic Nuclei},
number = 4,
volume = 79,
place = {United States},
year = {Fri Jul 15 00:00:00 EDT 2016},
month = {Fri Jul 15 00:00:00 EDT 2016}
}