Skip to Main Content
 

Global Search Box

 
 
 

ETD Abstract Container

Abstract Header

Thermal Properties of Nuclei and Their Level Densities

Al Mamun, Md. Abdullah
http://orcid.org/0000-0002-2655-1244
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1442937269

Abstract Details

2015, Master of Science (MS), Ohio University, Physics and Astronomy (Arts and Sciences).
The primary objective of this thesis is to develop the theoretical tools for a rapid calculation of nuclear level densities for neutron-rich nuclei not found in the laboratory, but commonly encountered in astrophysical settings. Toward this goal, the thermal properties of 4820Ca , 13250Sn, 20882Pb and 5727Co were calculated using statistical methods. The single-particle levels for these nuclei were obtained from thermal Hartree-Fock and Hartree-Fock-Bogoliubov calculations for two model Hamiltonians based on the Skyrme forces SkO' and SkM*. The calculated nuclear level densities are in better agreement with experimental data for 5727Co and 20882Pb for the SkO' model. Both models fail at very low excitation energies owing to the approximations made in the statistical treatment. A new finding of this work is the discontinuity in the specific heat at constant volume for 5727Co in the excitation energy range of 1.5-3 MeV, which indicates a phase transition from the superfluid state to normal matter. To our knowledge, this feature has not been reported in the literature for this nucleus. We also found the physical reason why calculations for open shell nuclei sometimes yield a diverging pattern in the single-particle level densities at low excitation energies. This behavior is caused by a combination of two effects: high degeneracies and close proximity of partially filled levels to the chemical potentials of neutrons and protons. A practical strategy is proposed for future work in which results of more microscopic, but computer-intensive, calculations that avoid the divergences found in statistical treatments at very low excitation energies are stitched with the results at moderate to high excitation energies from the latter approach.
Madappa Prakash, Prof. (Advisor)
Douglas Clowe, Prof. (Committee Member)
Gang Chen, Prof. (Committee Member)
109 p.
Physics
level density; thermal hartree fock; hartree fock with pairing; BCS in nuclei; Skyrme parametrization; nuetron rich nuclei; phase transition; cobalt57; spin cutoff parameter; specific heat at constant volume

Recommended Citations

Citations

  • Al Mamun, M. A. (2015). Thermal Properties of Nuclei and Their Level Densities [Master's thesis, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1442937269

    APA Style (7th edition)

  • Al Mamun, Md. Abdullah. Thermal Properties of Nuclei and Their Level Densities. 2015. Ohio University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1442937269.

    MLA Style (8th edition)

  • Al Mamun, Md. Abdullah. "Thermal Properties of Nuclei and Their Level Densities." Master's thesis, Ohio University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1442937269

    Chicago Manual of Style (17th edition)

ohiou1442937269
1,221
© 2015, some rights reserved.Creative Commons License Thermal Properties of Nuclei and Their Level Densities by Md. Abdullah Al Mamun is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by Ohio University and OhioLINK.