Level structure of 191Os: Coexisting oblate and prolate configurations

Autor: I. Förster, P. von Brentano, H. Faust, S.J. Robinson, D. Lieberz, G. Hlawatsch, R. F. Casten, W. R. Kane, H.G. Börner, T. von Egidy, H. Lindner, G.G. Colvin, M. R. Macphail, F. Hoyler, P. Geltenbort
Rok vydání: 1991
Předmět:
Zdroj: Nuclear Physics A. 534:255-293
ISSN: 0375-9474
DOI: 10.1016/0375-9474(91)90498-u
Popis: An extensive level scheme for the transitional nucleus 191 Os has been constructed on the basis of (n, γ), (n, e − ) and (d, t) reaction data. γ-rays following thermal capture and average resonance capture (ARC) were detected with pair spectrometers. Secondary γ-ray spectra were obtained with the GAMS bent crystal spectrometers. The high precision of the resultant energies was the critical factor in developing a level scheme on the basis of Ritz combinations. γγ coincidences were obtained from both primary and secondary transitions. Conversion electrons, detected with the BILL spectrometer, gave multipolarity information. The (d, t) reaction measured with a Q3D magnetic spectrometer gave additional information on the hole states in 191 Os. A discussion of the resulting level scheme briefly reviews the fragmentation of negative-parity strength but focuses mostly on a rare example of an anti-aligned decoupled set of coexisting positive-parity states. For these, triaxial particle-plus-rotor calculations are carried out. Reasonable agreement is obtained and the calculations also explain the unusually strong population in (n, γ) of this set of mostly medium spin states.
Databáze: OpenAIRE