Transition strengths and degree of deformation in {sup 79}Sr
- Department of Physics and Astronomy, Ohio Wesleyan University, Delaware, Ohio 43015 (United States)
- Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)
- Gesellschaft fuer Schwerionenforschung (GSI), Planckstr. 1, D-64291 Darmstadt (Germany)
- Department of Physics and Joint Institute of Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
- Department of Chemistry and Physics, Purdue University Calumet, Hammond, Indiana 46323 (United States)
- Department of Physics and Astronomy, Earlham College, Richmond, Indiana 47374 (United States)
High-spin states in {sup 79}Sr were studied using the {sup 54}Fe({sup 28}Si,2pn) reaction at 90 MeV, with a thick 14-mg/cm{sup 2} {sup 54}Fe target used to stop all recoils. Prompt {gamma}-{gamma} coincidences were detected using the Florida State University Compton-suppressed Ge array consisting of three Clover detectors and seven single-crystal detectors. The most recent {sup 79}Sr level scheme has been confirmed in three separate band structures up to a spin as high as the ((37/2){sup +}) yrast state based on {gamma}-ray coincidence relations, intensity and effective lifetime measurements, and directional correlation of oriented nuclei ratios. Lifetimes of 33 excited states were measured using the Doppler-shift attenuation method, with the experimental line shapes obtained at two separate observation angles and by gating from above the transitions of interest whenever possible. Transition quadrupole moments Q{sub t} inferred from the lifetimes indicate a high degree of collectivity and deformation over a rather wide range of spins in all three observed bands, with evidence for modest reductions in the values with increasing spin. The changes in Q{sub t} are attributed to the onset of quasiproton alignment and are supported qualitatively by the predictions of the projected shell model and cranked Woods-Saxon calculations in conjunction with the cranked shell model. Lifetimes measured in a band based on the [431](1/2){sup +} intrinsic Nilsson configuration suggest a large quadrupole deformation ({beta}{sub 2}{approx_equal}0.41) associated with this band, providing another example of the strong deformation-driving properties of the d{sub 5/2} intruder orbital in the mass 80 region.
- OSTI ID:
- 20995124
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 75, Issue 3; Other Information: DOI: 10.1103/PhysRevC.75.034311; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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