Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Winger, A. Jeff
Committee Member
Arnoldus, Henk
Committee Member
Rykaczewski, P. Krzysztof
Committee Member
Srinivasan, Radhakrishnan
Committee Member
Ma, Wenchao
Date of Degree
5-1-2010
Original embargo terms
MSU Only Indefinitely
Document Type
Dissertation - Campus Access Only
Major
Engineering Physics
Degree Name
Doctor of Philosophy
College
College of Arts and Sciences
Department
Department of Physics and Astronomy
Abstract
β decay studies of nuclei at the limits of stability are essential in evaluating the physical aspects behind the structural changes, particle configurations and interactions in neutronor proton-rich systems. Isobarically purified beams were used at the Holifeld Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study the β decays of 75Cu and 77Cu. Two different experiments were performed. In the first study, only concernig the decay of 77Cu, the 25-MV tandem accelerated ions were time-tagged using a micro-channel plate detector, passed through a six-segment ion chamber, and implanted on the tape of a moving tape collector. The passage through an ion chamber insured the ion identification by energy loss in the six segments. The Low Energy Radioactive Ion Beam Spectroscopy Station consisting of a universal detector support with four Ge clover detectors, two â detectors and a moving tape collector, was used in the second experiment. Bypassing of the tandem accelerator gave a factor of 10 gain in beam intensity for both 75Cu and 77Cu. These experiments resulted in considerable information on the previously unknown level structure of 75Zn with some 120 γ-ray transitions placed in a level scheme containing 59 levels including two above the neutron separation energy. We have also identified the previously unknown 1/2− isomeric state at 127 keV. A total of 64 γ rays were placed in a level scheme for 77Zn containing 35 excited states including one state above the neutron separation energy, while two γ rays were observed for the βn branch to states in 76Zn. The growth and decay curves of some prominent γ rays indicate a single β-decaying state with a half-life of 480(9) ms. The decay pattern for 77Cu, with observed feeding of 8(3)% to the 7/2+ 77Zng and 6(3)% to the 1/2− 77Znm, in contrast to the large feeding observed for decay of πp3/2 73Cug to 1/2− 73Zng, strongly suggests a πf5/2 ground state for the studied 77Cu activity. Results will be presented and the prospects for future possible studies will also be discussed.
URI
https://hdl.handle.net/11668/16288
Recommended Citation
Ilyushkin, Sergey V., "The [Beta] and [Beta]-delayed neutron decay studies of 75CU and 77CU" (2010). Theses and Dissertations. 4257.
https://scholarsjunction.msstate.edu/td/4257
Comments
beta||decay||neutron||isomer