Search ETDs:
Spectroscopy of the A = 33 Isobars in the Island of Inversion

2018, Doctor of Philosophy (PhD), Ohio University, Physics and Astronomy (Arts and Sciences).
The question of the immutability of the traditional "magic numbers" and structure of exotic nuclei near to shell closures has long been an area of interest both experimentally and theoretically. The neutron-rich Mg isotopes around N=20 are examples of a region where the expected spherical shell gap has narrowed or disappeared entirely. The "Island of Inversion," centered around 32Mg, is a region where a narrowed N=20 shell gap and collective np-nh excitations result in nuclei with deformed ground states. However, despite years of theoretical and experimental efforts, a complete picture of the detailed nature of deformation in this region has not been achieved and the level schemes remain largely incomplete for many of these neutron-rich nuclei. Furthermore, the presence of rotational band structures, which are key signatures of deformation, have only recently been observed in this region.

Two experiments were performed at the National Superconducting Cyclotron Laboratory (NSCL) in order to probe the structure of the A=33 isobars in the "island of inversion." A beta -decay experiment (NSCL e14063) was performed to investigate the level schemes and decay schemes for the decay of 32Na to 32Mg, 33Na to 33Mg, 33Na to 33Mg to 33Al, and 33Mg to 33Al. The details of the experiment are discussed and level schemes and decay schemes, along with the implications for the observed structure. Additionally, the half-lives for 32,33Na and 33Mg were determined.

A measurement (NSCL e11029) of the low-lying level structure of 33Mg populated by a two-stage projectile fragmentation reaction and studied with GRETINA was also performed. The experimental setup is discussed along with the gamma-ray singles and gamma-gamma coincidence analysis used to construct the level scheme for 33Mg. The experimental level energies, ground state magnetic moment, intrinsic quadrupole moment, and gamma-ray intensities are compared to a leading order rotational model in the strong-coupling limit. Lastly, the level schemes from both measurements are discussed along with potential future projects.
Heather Crawford (Advisor)
Carl Brune (Committee Member)
Daniel Phillips (Committee Member)
Alexander Neiman (Committee Member)
Katherine Cimatu (Committee Member)
136 p.

Recommended Citations

Hide/Show APA Citation

Richard, A. (2018). Spectroscopy of the A = 33 Isobars in the Island of Inversion. (Electronic Thesis or Dissertation). Retrieved from https://etd.ohiolink.edu/

Hide/Show MLA Citation

Richard, Andrea. "Spectroscopy of the A = 33 Isobars in the Island of Inversion." Electronic Thesis or Dissertation. Ohio University, 2018. OhioLINK Electronic Theses and Dissertations Center. 21 Nov 2018.

Hide/Show Chicago Citation

Richard, Andrea "Spectroscopy of the A = 33 Isobars in the Island of Inversion." Electronic Thesis or Dissertation. Ohio University, 2018. https://etd.ohiolink.edu/

Files

Richard, Andrea Accepted Dissertation 2-19-18 Sp 18.pdf (14.07 MB) View|Download