Nuclear-structure studies of sup 73 Br, sup 75 Br and investigation of oblate shape in sup 71 Se

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5712794

Zhao, X

Three experiments have been performed to establish the band structure for {sup 73}Br nucleus. The experiment at the University of Rochester used a Recoil Mass Spectrometer to identify {sup 73}Br transitions, by employing the reaction {sup 54}Fe({sup 28}Si,xp,xn) at 128 MeV energy. The transitions which appeared in the mass 73 gate were compared with all other mass gates to ensure no feed through from other reaction channels. The following two experiments were done at the Holifield tandem accelerator. The first was a neutron-{gamma}, and {gamma}-{gamma} experiment to verify {sup 73}Br transitions obtained from the RMS data, and the second was a high quality {gamma}-{gamma} coincidence experiment with 20 BGO shielded gamma-ray detectors to build the {sup 73}Br band structure. The nuclear structure of {sup 73}Br reveals three rotational bands up to high spins. A positive parity, positive signature band was observed up to 29{sup {plus}}/2, and is interpreted as a band built upon an aligned 9{sup {plus}}/2 proton orbital. Strong B(E2) values, potential energy surface calculations as a function of deformation parameters ({beta}{sub 2},{gamma}) and the moment of inertia of the band indicate that the {sup 73}Br deformation parameters are ({beta}{sub 2} {equals} 0.38,{gamma} {equals} -15{degree}), which is a triaxial shape with large quadrupole deformation. This is consistent with the neighboring {sup 75}Br results. Two in-beam gamma-ray experiments were also done for {sup 71}Se to look for possible oblate bands. New transitions in 71 Se were established from RMS-{gamma}, RMS-n-{gamma} and RMS-p-{gamma} spectra. Later {gamma}-{gamma} coincidence data revealed a {Delta}I {equals} 1 positive parity rotational band.

• Research Organization: Vanderbilt Univ., Nashville, TN (USA)
• OSTI ID: 5712794
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BROMINE 73
NUCLEAR STRUCTURE
BROMINE 75
SELENIUM 71
COINCIDENCE METHODS
ENERGY-LEVEL TRANSITIONS
EXPERIMENTAL DATA
GAMMA RADIATION
HHIRF ACCELERATOR
IRON 54 TARGET
MASS SPECTROMETERS
ROTATIONAL STATES
SILICON 28 REACTIONS
ACCELERATORS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BROMINE ISOTOPES
CHARGED-PARTICLE REACTIONS
COUNTING TECHNIQUES
DATA
ELECTROMAGNETIC RADIATION
ELECTRON CAPTURE RADIOISOTOPES
ENERGY LEVELS
EVEN-ODD NUCLEI
EXCITED STATES
HEAVY ION ACCELERATORS
HEAVY ION REACTIONS
HOURS LIVING RADIOISOTOPES
INFORMATION
INTERMEDIATE MASS NUCLEI
IONIZING RADIATIONS
ISOTOPES
MEASURING INSTRUMENTS
MINUTES LIVING RADIOISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
RADIATIONS
RADIOISOTOPES
SELENIUM ISOTOPES
SPECTROMETERS
TARGETS
651620* - Nuclear Properties & Reactions
A=59-89
Experimental