Identification of the unfavored N=7 superdeformed band in Hg191

A new superdeformed band has been identified in Hg191 bringing the total number of bands observed in this nucleus to four. The new band has properties similar to those of a superdeformed band reported recently in Hg193. Both bands are believed to be built on the unfavored signature of the j15/2 intruder configuration. Comparisons between the data and cranked Woods-Saxon calculations highlight the strengths and weaknesses of theory in describing high-N orbitals at large deformation

High-spin yrast isomers in 204^{204}HG

This work reports the observation of high-spin states in 204Hg using time-correlated γ-ray spectroscopy to identify isomers populated in deep-inelastic collisions of a ~1.4 GeV 208Pb beam on a thick 238U target. A high-spin isomer with τ>1 μs has been found and the observed γ-ray decay has established the yrast states below it, including another isomer with τ=33(3) ns. Spin and parity assignments were based on conversion coefficients deduced from intensity balance and on the observed γ-decay patterns. The experimental results are compared with shell model calculations that include four holes in the entire configuration space between 132Sn and 208Pb. Observed agreement with the calculation gave the supplementary arguments to the spin-parity assignments and clarified configurations of experimental states. The τ>1 μs isomer is suggested to be the πh-2 11/2ν-2 13/2, 22+ states that results from the coupling to maximum spin available for the four valence holes. Few prompt transitions feeding the isomer were also observed

Investigation of the magnetic rotation in 196^{196}Pb

none23Lifetimes for low-lying members of the irregular ΔI = 1 band in 196Pb have been measured by means of the EUROBALL spectrometer using the coincidence recoil distance technique. The 164Dy(36S,4n)196Pb reaction at a beam energy of 168 MeV was used. The data were analyzed with the differential decay-curve method (DDCM). A characteristic drop in the reduced transition probabilities with increasing angular momentum was observed in agreement with predictions by the semiclassical model for the shears mechanism.noneG.KEMPER; A.DEWALD; I.WIEDENHOVER; R.PEUSQUENS; S.KASEMANN; K.O.ZELL; P.VON BRENTANO; H.HUBEL; S.CHMEL; A.GORGEN; D.BAZZACCO; R.VENTURELLI; LUNARDI S.; D.R.NAPOLI; F.HANNACHI; A.LOPEZMARTENS; R.KRUCKEN; J.R.COOPER; R.M.CLARK; M.A.DELEPLANQUE; I.Y.LEE; A.O.MACHIAVELLI; F.S.STEPHENSG., Kemper; A., Dewald; I., Wiedenhover; R., Peusquens; S., Kasemann; K. O., Zell; P., VON BRENTANO; H., Hubel; S., Chmel; A., Gorgen; D., Bazzacco; R., Venturelli; Lunardi, Santo; D. R., Napoli; F., Hannachi; A., Lopezmartens; R., Krucken; J. R., Cooper; R. M., Clark; M. A., Deleplanque; I. Y., Lee; A. O., Machiavelli; F. S., Stephen

Deutsche Forschungsanstalt fuer Luft- und Raumfahrt, Internationales Buero. Jahresbericht 1996

Available from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman