skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes

Abstract

The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (Y{sub e}) of the corematerial. It is suggested that the temporal variation of Y{sub e} within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly {sup 54-56}Fe, are considered to be key players in controlling Y{sub e} ratio via electron capture on these nuclides. Recently an improved microscopic calculation of weak-interaction-mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random-phase-approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic state-by-state calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the Y{submore » e} ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on {sup 54-56}Fe. The sensitivity of the pn-QRPA calculated capture rates to the deformation parameter is also studied in this work. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.« less

Authors:
 [1]
  1. Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences (Pakistan)
Publication Date:
OSTI Identifier:
22156404
Resource Type:
Journal Article
Journal Name:
Physics of Atomic Nuclei
Additional Journal Information:
Journal Volume: 76; Journal Issue: 3; Other Information: Copyright (c) 2013 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7788
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; COSMIC ELECTRONS; COSMIC POSITRONS; DEFORMATION; ELECTRON CAPTURE; EXPLOSIONS; INTERPOLATION; IRON 54; IRON 55; IRON 56; IRON ISOTOPES; NEUTRONS; NUCLEOSYNTHESIS; PROTONS; RANDOM PHASE APPROXIMATION; RELIABILITY; SENSITIVITY; SIMULATORS; STAR EVOLUTION; STARS; WEAK INTERACTIONS

Citation Formats

Nabi, Jameel-Un, and Tawfik, Abdel Nasser, E-mail: a.tawfik@eng.mti.edu.eg. Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes. United States: N. p., 2013. Web. doi:10.1134/S1063778813020142.
Nabi, Jameel-Un, & Tawfik, Abdel Nasser, E-mail: a.tawfik@eng.mti.edu.eg. Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes. United States. https://doi.org/10.1134/S1063778813020142
Nabi, Jameel-Un, and Tawfik, Abdel Nasser, E-mail: a.tawfik@eng.mti.edu.eg. 2013. "Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes". United States. https://doi.org/10.1134/S1063778813020142.
@article{osti_22156404,
title = {Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes},
author = {Nabi, Jameel-Un and Tawfik, Abdel Nasser, E-mail: a.tawfik@eng.mti.edu.eg},
abstractNote = {The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (Y{sub e}) of the corematerial. It is suggested that the temporal variation of Y{sub e} within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly {sup 54-56}Fe, are considered to be key players in controlling Y{sub e} ratio via electron capture on these nuclides. Recently an improved microscopic calculation of weak-interaction-mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random-phase-approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic state-by-state calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the Y{sub e} ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on {sup 54-56}Fe. The sensitivity of the pn-QRPA calculated capture rates to the deformation parameter is also studied in this work. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.},
doi = {10.1134/S1063778813020142},
url = {https://www.osti.gov/biblio/22156404}, journal = {Physics of Atomic Nuclei},
issn = {1063-7788},
number = 3,
volume = 76,
place = {United States},
year = {Fri Mar 15 00:00:00 EDT 2013},
month = {Fri Mar 15 00:00:00 EDT 2013}
}