Studies of Tz= -3/2 nuclei of astrophysical interest

Abstract

This thesis presents a summary of experimental studies of -decaying Tz = ð€€€3=2 nuclei 23Al and 31Cl. The properties of these nuclei and the respective -decay daughters, 23Mg and 31S, have an in uence on the end products of ONe nova outbursts. The experiments were carried out at the IGISOL facility in the Accelerator laboratory of University of Jyväskylä and at the Cyclotron institute of Texas A&M University. The mass excess of 23Al was determined with Penning trap mass spectrometry by using the JYFLTRAP setup at IGISOL facility. The new mass excess is two orders of magnitude more precise than the previous value. A good agreement between theory and experimental values was found when applying the newly determined mass value to test the isobaric multiplet mass equation in the A = 23; T = 3=2 isobaric multiplet. A -decay setup was developed for the focal plane of momentum achromat recoil spectrometer in Texas A&M University. The study of the -decay of 23Al brought new information to the discrepancy between earlier measurements concerning the low energy protons emitted from 23Mg. The new results completed data needed to determine the resonance strength of the astrophysically most relevant resonance in the 22Na(p, )23Mg reaction by completely indirect data. The study of the - decay of 31Cl con rmed the key ndings of the previous studies. In addition, several states in 31S, including the IAS of 31Cl, were observed for the rst time in a -decay experiment. The results improve the energies and constrain the possible J of the states relevant for the 30P(p, )31S reaction. A cryogenic ion guide was developed and the results of these tests are presented