| 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. |
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| 3. |
- Cederwall, Bo, et al.
(författare)
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NEW FEATURES OF SUPERDEFORMED BANDS IN HG-194
- 1994
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 72:20, s. 3150-3153
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Tidskriftsartikel (refereegranskat)abstract
- Two new features of superdeformed (SD) bands in the A almost-equal-to 190 region emerge from a study of Hg-194 with the Gammasphere detector array. A decrease of the dynamic moment of inertia is observed for rotational frequencies HBARomega greater-than-or-equal-to 0.4 MeV, confirming long standing expectations based on mean field calculations with pairing. Evidence for a small staggering in the SD transition energies is also observed, suggesting the presence of terms with fourfold symmetry in the SD Hamiltonian.
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| 4. |
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| 5. |
- HUGHES, JR, et al.
(författare)
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LIFETIME MEASUREMENT IN EXCITED AND YRAST SUPERDEFORMED BANDS IN HG-194
- 1994
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 72:6, s. 824-827
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear level lifetimes have been measured in two superdeformed bands in Hg-194 using the Doppler-shift attenuation method. Average transition quadrupole moments derived from the life-times of an excited and yrast superdeformed bands are Q(t) = 17.6(30) and 17.2(20) eb, respectively. The Doppler shifts of the excited band relative to the yrast band indicate a slight difference in quadrupole moments [+4(5)%], assuming similar side feeding. These results imply that the second well is stable and rigid with respect to the particle excitation responsible for this excited band.
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| 6. |
- ASZTALOS, SJ, et al.
(författare)
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CONFIRMATION OF THE SUPERDEFORMED BAND IN PB-192
- 1995
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Ingår i: Zeitschrift für Physik A Hadrons and Nuclei. - 0939-7922 .- 1431-5831. ; 352:3, s. 239-240
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Pb-192 were populated via the reaction Yb-173(Mg-24,5n) at a beam energy of 140 MeV, and the resulting gamma-rays were deteced using GAMMA-SPHERE. A previously observed superdeformed band in Pb-192 has been confirmed.
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| 7. |
- Baldsiefen, G, et al.
(författare)
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Shears bands in Pb-193
- 1996
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 54:3, s. 1106-1116
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Tidskriftsartikel (refereegranskat)abstract
- Four bands of enhanced dipole transitions, with weak crossovers, have been observed in Pb-195. Three of these bands are connected to the spherical levels. in addition, the spherical level scheme has been extended. The nuclear spectroscopy was done with the early implementation of GAMMASPHERE and HERA arrays of Get detectors. The nucleus Pb-193 was populated in the Yb-174(Mg-24,5n) reaction at beam energies of 129, 131, and 134 MeV. The experimental results are compared to tilted-axis cranking calculations. The systematical behavior of the dipole bands in the heavier odd-A Pb isotopes, Pb-195,Pb-197,Pb-199,Pb-201, is also discussed.
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| 8. |
- BERNSTEIN, LA, et al.
(författare)
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SUPERDEFORMATION IN ER-154
- 1995
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 52:3, s. R1171-R1174
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Tidskriftsartikel (refereegranskat)abstract
- A superdeformed (SD) band consisting of 13 gamma-ray transitions has been observed in Er-154, an isotone of Dy-152(66). The experiment was performed using the Sn-118(Ar-40,4n) reaction at E(Ar-40)=185 MeV and the early implementation of GAMMASPHERE. This is an observation of a SD band in the A approximate to 150 region with a proton number greater than 66. The J((2)) moment of inertia of the band is constant above ($) over bar h omega=0.45 MeV and shows a sharp rise below this value suggesting a paired band crossing. These results suggest that total Routhian surface calculations fail to accurately predict the deformation of the band.
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| 9. |
- Brinkman, M J, et al.
(författare)
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Decay from a superdeformed band in Pb-194
- 1996
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:4, s. R1461-R1464
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Tidskriftsartikel (refereegranskat)abstract
- Three experiments using the (174) Yb(Mg-25,5n)Pb-194 reaction have been undertaken at the Early Implementation of Gammasphere to study the decay of known superdeformed states in Pb-194. A single discrete transition with an energy of 2.746(2) MeV carrying 6(2)% of the full superdeformed band intensity has been identified. A discussion of our results and the assignment of the 2.746-MeV transition as a discrete gamma ray directly connecting the superdeformed 8(+) and low-lying 6(+) levels will be presented.
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| 10. |
- Cederwall, Bo, et al.
(författare)
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MEASUREMENT OF ULTRA-FAST GAMMA-RAY TRANSITIONS FROM HEAVY-ION COMPOUND NUCLEUS REACTIONS
- 1995
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 354:2-3, s. 591-594
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Tidskriftsartikel (refereegranskat)abstract
- A method for correcting target-thickness-induced Doppler broadening in gamma-ray spectra from weakly populated, very short-lived (femtosecond) states is presented. The method is illustrated by an analysis of superdeformed transitions in Dy-152,Dy-153 for which the validity of the procedure could be verified consistently from previous lifetime measurements in Dy-152. Furthermore, estimates of the superdeformed lifetimes, previously not measured in Dy-153, are obtained.
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