Degree
Doctor of Philosophy (PhD)
Department
Physics and Astronomy
Document Type
Dissertation
Abstract
The unstable nature of 9B makes it a challenging isotope to study. The first-excited state of 9B has been particularly difficult to characterize. Since the first experimental observation of this state in 1955, many experimental and theoretical nuclear structure studies have sought to classify it, but with large discrepancies in the energy and width values from these results, the properties of the state remain inconclusive.
An experiment using the 10B(3He,α)9B reaction was performed at the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University in an effort to populate and characterize this elusive state in 9B. A 7.5-MeV 3He beam was incident on an enriched 10B target at the entrance of the Super-Enge Split-Pole Spectrograph (SE-SPS). The SE-SPS focal plane detector has particle identification capabilities that were used to isolate the reaction of interest. This experiment utilized the large solid-angle coverage of the Silicon Array for Branching Ratio Experiments (SABRE) at backward laboratory angles in order to detect multiple decay particles from 9B in coincidence with the alphas from the (3He,α) reaction detected at the focal plane of the SE-SPS. These features, as well as the digital electronics used for data acquisition, set this experiment apart from previous 10B(3He,α)9B studies by providing gated 9B spectra with high-resolution peaks and low-background statistics. Data was also taken on a LiF target to utilize the well-studied 7Li(3He,α)6Li reaction and 6Li low-lying structure for calibration. The decay particles from 6Li and 9B are detected in SABRE and the Invariant Mass Method is used to reconstruct the original, unstable states. These reconstructed spectra are then characterized with multi-breakup Monte Carlo simulations. The 10B(3He,α)9B experiment, 7Li(3He,α)6Li calibrations, analysis methods and results will be presented in this work.
Date
1-9-2025
Recommended Citation
Shaffer, Rachel M., "Studying The Low-Lying Structure of 9B via The 10B(3He,a)9B Reaction" (2025). LSU Doctoral Dissertations. 6662.
https://repository.lsu.edu/gradschool_dissertations/6662
Committee Chair
Marley, Scott T.