| 1. |
- BERNSTEIN, LA, et al.
(författare)
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ONSET OF COLLECTIVITY IN NEUTRON-DEFICIENT PO-196,PO-198
- 1995
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 52:2, s. 621-627
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Tidskriftsartikel (refereegranskat)abstract
- We have studied via in-beam gamma-ray spectroscopy Po-196 and Po-198, which are the first neutron-deficient Po isotopes to exhibit a collective low-lying structure. The ratios of yrast state energies and the E2 branching ratios of transitions from non-yrast to yrast states are indicative of a low-lying vibrational structure. The onset of collective motion in these isotopes can be attributed to the opening of the neutron i(13/2) orbital at N approximate to 112 and the resulting large overlap between the two valence protons in the h(9/2) orbital and the valence neutrons in the i(13/2) orbital.
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| 2. |
- Cederwall, Bo, et al.
(författare)
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NEW OBLATE BAND IN HG-196 WITH QUENCHED M1 STRENGTH
- 1993
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 47:6, s. R2443-R2446
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in the nucleUs Hg-196 were populated in the reaction (Os(Be,5n))-Os-192 at a beam energy of 65 MeV. A regular rotational-like DELTAI = 1 band has been observed up to an excitation energy of E* almost-equal-to 8.7 MeV and spin I almost-equal-to 30hBAR. This is the second observation of a band of this character in a mercury isotope. The experimental results are compared with mean field calculations and semiclassical estimates based on the Donau-Frauendorf formalism. The mercury bands show significantly lower B(M1)/B(E2) branching ratios as compared with similar bands in light lead nuclei. This difference may be more readily explained by a difference in single-particle structure rather than by large differences in deformation between the lead and mercury configurations.
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| 3. |
- FALLON, P, et al.
(författare)
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EVIDENCE FOR M1 TRANSITIONS BETWEEN SUPERDEFORMED STATES IN HG-193
- 1993
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 70:18, s. 2690-2693
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Tidskriftsartikel (refereegranskat)abstract
- Two-way decay has been observed between superdeformed bands in Hg193. it is proposed the decays have M 1 multipolarity and connect signature partner bands. Candidates for the two-way gamma decays connecting superdeformed bands are observed for the first time.
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| 4. |
- HUGHES, JR, et al.
(författare)
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LIFETIME MEASUREMENTS IN THE REGULAR DELTA-I = 1 OBLATE BAND IN PB-197
- 1993
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 48:5, s. R2135-R2139
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Tidskriftsartikel (refereegranskat)abstract
- Lifetimes of states in the regular DELTAI = 1 band in 197Pb have been measured with the Doppler-shift attenuation method. Excited states in 197Pb were populated using the Sm-154(48Ca, 5n) reaction at E(b) = 210 MeV. The target consisted of 1 mg/cm2 Sm-154 evaporated onto a 10 mg/cm2 Au backing. Discernible lineshapes for gamma rays in the energy range 300 < E(gamma) < 500 keV in the regular band were observed in a spectroscopic study with the 20 Ge-detector array, HERA. Level lifetimes were obtained from a lineshape analysis. Averaged reduced transition strengths, B(M1) approximately 1.7 W.u. and B(E2) approximately 18 W.u., are deduced and these are compared with theoretical predictions for the suggested configuration of this band.
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| 5. |
- VO, DT, et al.
(författare)
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SUPERDEFORMATION IN AU-191
- 1993
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 71:3, s. 340-343
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Tidskriftsartikel (refereegranskat)abstract
- A superdeformed band has been observed for the first time in an Au isotope. The reaction used was B-11 + W-186, demonstrating that very light ions can be used to populate superdeformed (SD) bands at high angular momentum. The band is assigned to 191Au. The gamma-ray energies are at the quarter-point energies of the 192Hg SD band, indicating that it is ''identical'' to that of 192Hg.
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