| Neutron-deficient nuclei in the vicinity of the N = Z = 50 doubly-magic shell closure were produced at the National Superconducting Cyclotron Laboratory to study their structure and their relevance in the astrophysical rp-process. The 100Sn nucleus is the heaviest particle-stable N = Z nucleus, and it is also thought to be doubly magic. Additionally, 100Sn and its closest neighbors lie in the path of rp-process, therefore, the production and study of the decay properties of these nuclei are of great interest for the experimental and theoretical nuclear physics and astrophysics community. Previous attempts to produce these nuclei were hampered by large amounts of contaminants produced with higher abundances than those of the nuclides of interst. The Radio Frequency Fragment Separator (RFFS) was designed and built at the NSCL in order to purify rare neutron-deficient secondary beams. The implementation of this device has made a number of beta-decay experiments feasible at the NSCL. The experiment described in this work (NSCL Experiment 07034) was the second one to utilize the RFFS to successfully determine beta-decay half-lives, beta-delay proton emission branching ratios and beta-delayed gamma spectroscopy.;The nuclei of interest were produced at NSCL via fragmentation of a 112Sn primary beam accelerated to 120 MeV/nucleon, impinging on a 9Be target. The secondary beam was first selected by the A1900 Fragment Separator and purified further with the RFFS. The N = Z nuclei 100Sn, 98In and 96 Cd were produced and their beta decay was studied. The observed production cross sections of these nuclei are lower than predicted by factors of 10--30. Their beta-decay half-lives were found to be 0.55(+0.70 -0.31) s for 100Sn, 0.66(40)s for an isomeric state in 98In, and 47(13) ms for its ground state, and 1.03 (0.2)s for 96Cd. The experimental determination of the half-life of 96Cd was of special interest as it was the last rp-process waiting point to be measured. The effect of the half-life of 96Cd on the nuclear abundances produced by an rp-process and the origin of the light-p nucleus 96 Ru were explored.;Other exotic nuclei produced in Experiment 07034 include 101Sn, 100,99In, 98,97Cd, 96,95,94Ag, 94,93,92Pd, 92,91Rh and 90,91Ru. For the cases with sufficiently high statistics their beta-decay half-lives were determined and compared with previous measurements and theoretical predictions. Several isomeric states were found and their decay modes analysed. In particular, a new microsecond isomer decaying by a gamma cascade was observed in 96Ag for the first time and the level scheme of this nucleus is presented, together with the results of two shell-model calculations performed within the (p1/2g9/2) and (p3/2p1/2 f5/2g9/2) model spaces, respectively. It was found that the shell model calculation with the larger model space reproduced level energies and isomeric decay half-lives reasonably well. |
