MSc Thesis Presentation: Searching for signatures of shape coexistence in 100 Ru

MSc Candidate

Sangeet-Pal Pannu

Abstract

The 100 Ru, Z=44 and N=56, is the last member of the Ru isotopes to remain classified as an ideal vibrational nucleus. With some of the other members, moving towards a new classification of shape coexisting nuclei, the question is posed on this nucleus, if it follows the slowly unraveling trend or truly holds to its previous classification. However, due to the poorly characterised low-energy spectra of 100 Ru the conclusion on the true nature of the nucleus is not currently possible. In order to elucidate the structural nature of the nucleus a neutron capture reaction on 99 Ru was completed at the Institut Laue-Langevin (ILL) in Grenoble, France. The decay of the 100 Ru was detected using the FIPPS and IFIN-HH gamma-ray spectrometers. The experiment resulted in a very high-statistics data set with a total of 30 billion gamma-ray events, which resulted in the observation of 78 levels, 300 gamma transitions, and 11 mixing ratios. The acquired data was also able to establish new band structures built on the 0_3+ and 0_4+ states and a newly observed gamma-band built on the 0_2+. Conclusions about the vibrational nature were established not to be consistent with the previous assignment, and an updated level structure was also provided.

Examination Committee

• Dr. Eric Poisson, Chair
• Dr. Paul Garrett, Advisor
• Dr. Ralf Gellert, Advisory Committee
• Dr. Liliana Caballero, Graduate Faculty