Date of Award
Doctor of Philosophy
Physics and Astronomy
The study of excited states in the N = 50 isotones ('82)Ge and ('83)As following the (beta) decay of the neutron-rich nuclei ('82)Ga and ('83)Ge is reported. This work was performed using the on-line isotope separator facility TRISTAN at Brookhaven National Laboratory. The ('83)Ge half-life was measured to be 1.85 (+OR-) 0.06 s. On the basis of (gamma) singles and (gamma)-(gamma) coincidence measurements a total of 51 (gamma) rays were placed in a level scheme for ('83)As with 27 levels up to 4.84 MeV. The ('82)Ga half-life was measured to be 0.62 (+OR-) 0.02 s. On the basis of (gamma) singles and (gamma)-(gamma) coincidence measurements, a total of 11 (gamma) rays were placed in a level scheme for ('82)Ge with 7 levels up to 3.26 MeV. These measurements also established the existence of delayed-neutron emission from ('82)Ga by the observance of 6 (gamma) rays associated with the depopulation of levels in ('81)Ge. An angular correlation measurement was performed for levels in ('82)Ge to establish J('(pi)) values with only tentative results. The level structure for the N = 50 isotones ('82)Ge, ('83)As, ('84)Se, ('85)Br, and ('86)Kr are compared with the results of a large-space shell-model calculation assuming an inert ('78)Ni core. The;results of this comparison do not establish the validity of the inert ('78)Ni core; ('1)DOE Report IS-T-1288. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Jeff Allen Winger
Winger, Jeff Allen, "Shell model studies of the N=50 isotones in the 78Ni 'doubly magic' region " (1987). Retrospective Theses and Dissertations. 11660.