Date of Award
8-2022
Degree Name
Doctor of Philosophy
Department
Physics
First Advisor
Michael Famiano, Ph.D.
Second Advisor
Zbigniew Chajecki, Ph.D.
Third Advisor
Elena Litvinova, Ph.D.
Fourth Advisor
Ramakrishna Guda, Ph.D.
Keywords
capture reaction cross-sections, Hg-196 (mercury-196), p-nuclei (proton-rich nuclei), self-calibrating target, targets for irradiation, Tl daughter nuclides
Abstract
Understanding the origin of all the chemical elements is an important question for the nuclear-astrophysics community. There are many unanswered questions like: What astrophysical events are responsible for the synthesis of what particular chemical elements? How many different elements were made in total? What is the abundance of each synthesized element? etc. Currently, scientists are largely depending upon theory and simulations to define nuclear and astrophysical reaction. This makes it critical to have accurate experimental nuclear physics data to input in astrophysical theoretical models. However, out of more than 20000 reactions involved in these calculations, only a very few are experimentally measured. The p-nuclei (proton-rich nuclei) are among the rarest of all the known stable nuclei. Most nuclei heavier than iron are produced through neutron capture processes, but p-nuclei are not thought to be produced via neutron-capture.The astrophysical processes responsible for the synthesis of p-nuclei, collectively termed as the p-process or the p-process nucleosynthesis, is not fully understood.
There are 35 known p-nuclei. The focus of this thesis is to study the process responsible for the synthesis of 196Hg, the heaviest known p-nucleus, through the method of activation using (p,γ), (p,α) and (p, n) reactions. The experiment is conducted using the Tandem Van de Graaff particle accelerator at theWesternMichigan University. A solid target with homogeneous concentration and uniform thickness is developed with mercury sulfide using the drop-casting method. The production methods are described along with the experimental method resulting in a selfcalibrating activation experiment.
The capture reaction cross-section is reported for 196Hg(p,γ)197Tl, 196Hg (p, n)196Tl, and 198Hg (p, n)198Tl. Natural mercury cross-sections are reported for 199Tl, 200Tl, and 202Tl. These cross-sections are important for understanding astrophysical processes responsible for the synthesis of p-nucleus, 196Hg. The measured crosssections as well as more details related to experiment are discussed.
Access Setting
Dissertation-Open Access
Recommended Citation
Bhatt, Khushi, "Studying the Synthesis of 196Hg at Astrophysically Relevant Energies Through the Measurement of Capture Reaction Cross-Sections of (p, γ) (p, n) and (p, α) Reactions" (2022). Dissertations. 3896.
https://scholarworks.wmich.edu/dissertations/3896