| 1. |
- 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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| 2. |
- McNabb, D P, et al.
(författare)
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Superdeformation in Po-198
- 1996
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:2, s. R541-R543
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Tidskriftsartikel (refereegranskat)abstract
- The Yb-174(Si-29,5n) reaction at 148 MeV with thin targets was used to populate high-angular momentum states in Po-198. Resulting gamma rays were observed with Gammasphere. A weakly populated superdeformed band of 10 gamma-ray transitions was found and has been assigned to Po-198. This is the first observation of an SD band in the A approximate to 190 region in a nucleus with Z > 83. The J((2))) of the new band is very similar to those of the yrast SD bands in Hg-194 and Pb-196. The intensity profile suggests that this band is populated through states close to where the SD band crosses the yrast line and the angular momentum at which the fission process dominates.
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| 3. |
- Rudolph, Dirk, et al.
(författare)
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Rotational Bands in the Doubly Magic Nucleus 56Ni
- 1999
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Ingår i: Physical Review Letters. - 1079-7114. ; 82:19, s. 3763-3766
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Tidskriftsartikel (refereegranskat)abstract
- Structures of the medium- to high-spin states in the doubly magic nucleus Ni-56 have been investigated using the reaction Si-28(Ar-36, 2 alpha) and the gamma-ray spectrometer Gammasphere in conjunction with the 4 pi charged-particle detector array Microball. Two well-deformed rotational bands have been identified. There is evidence that one of the bands, which is identical to a sequence in the odd-odd neighbor Cu-58, partially decays via proton emission into the ground state of Co-55. Predictions of extensive large-scale shell-model and cranked Hartree-Fock and Hartree-Fock-Bogolyubov calculations are compared with the experimental data.
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| 4. |
- Sylvan, G N, et al.
(författare)
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Deformation driving intruder orbitals in Kr-77
- 1997
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 56:2, s. 772-781
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Kr-77 were identified via analysis of prompt gamma-gamma coincidences in the Ni-58(Si-29,2 alpha 2p) reaction at 128 MeV at the Gammasphere facility. Evaporation channel selection was achieved using the 95 element Microball charged-particle detector. 27 new states and 42 new transitions were found, The positive-parity bands were confirmed and the alpha=-1/2 band extended to 39/2(+). The negative-parity signature pair was extended to 31/2(-) and 37/2(-). Two new high-lying negative-parity bands were found extending from a state of spin I = 15/2 and energy 2.6 MeV to 17.4 MeV at I = (55/2). The new bands appear highly deformed and become yrast at high spin. A three-quasiparticle structure based on deformation driving, low-K unique-parity and intruder orbitals is suggested for them.
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| 5. |
- LaFosse, D R, et al.
(författare)
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Search for hyperdeformation in Gd-146,Gd-147
- 1996
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 54:4, s. 1585-1588
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Tidskriftsartikel (refereegranskat)abstract
- A search was undertaken to look for evidence of hyperdeformation in Gd-146,Gd-147. Three experiments employing Gammasphere for gamma-ray detection coupled with the Microball for channel selection via charged particle detection were carried out with increasing detection sensitivity and statistics. No definitive evidence for band structures that could be assigned to hyperdeformation could be found. Candidates previously reported are shown not to have properties consistent with a band structure.
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| 6. |
- 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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| 7. |
- CRISTANCHO, F, et al.
(författare)
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MULTIPLE SUPERDEFORMED BANDS IN SR-81
- 1995
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Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 357:3, s. 281-286
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Tidskriftsartikel (refereegranskat)abstract
- Four superdeformed bands extending over five to twelve transitions have been identified in Sr-81 from a study With the Gammasphere array and the Microball charged-particle array, One of the bands shows an upbend in the dynamic moment of inertia at a rotational frequency of 1.2 MeV and all bands exhibit a nearly constant moment of inertia below that frequency.
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| 8. |
- Gorunova, Ludmila, et al.
(författare)
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Nonrandom chromosomal aberrations and cytogenetic heterogeneity in gallbladder carcinomas
- 1999
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Ingår i: Genes, Chromosomes and Cancer. - 1045-2257. ; 26:4, s. 21-312
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Tidskriftsartikel (refereegranskat)abstract
- Chromosome banding analysis of 11 short-term cultured gallbladder carcinomas revealed acquired clonal aberrations in seven tumors (five primary and two metastases). Three of these had one clone, whereas the remaining four were cytogenetically heterogeneous, displaying two to seven aberrant clones. Of a total of 21 abnormal clones, 18 had highly complex karyotypes and three exhibited simple numerical deviations. Double minutes and homogeneously staining regions were observed in one and two carcinomas, respectively. To characterize the karyotypic profile of gallbladder cancer more precisely, we have combined the present findings with our three previously reported cases, thereby providing the largest cytogenetic database on this tumor type to date. A total of 287 chromosomal breakpoints were identified, 251 of which were found in the present study. Chromosome 7 was rearranged most frequently, followed by chromosomes 1, 3, 11, 6, 5, and 8. The bands preferentially involved were 1p32, 1p36, 1q32, 3p21, 6p21, 7p13, 7q11, 7q32, 19p13, 19q13, and 22q13. Nine recurrent abnormalities could, for the first time, be identified in gallbladder carcinoma: del(3)(p13), i(5)(p10), del(6)(q13), del(9)(p13), del(16)(q22), del(17)(p11), i(17)(q10), del(19)(p13), and i(21)(q10). The most common partial or whole-arm gains involved 3q, 5p, 7p, 7q, 8q, 11q, 13q, and 17q, and the most frequent partial or whole-arm losses affected 3p, 4q, 5q, 9p, 10p, 10q, 11p, 14p, 14q, 15p, 17p, 19p, 21p, 21q, and Xp. These chromosomal aberrations and imbalances provide some starting points for molecular analyses of genomic regions that may harbor genes of pathogenetic importance in gallbladder carcinogenesis. Genes Chromosomes Cancer 26:312-321, 1999.
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| 9. |
- JIN, HQ, et al.
(författare)
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IDENTIFICATION AND QUADRUPOLE-MOMENT MEASUREMENT OF A SUPERDEFORMED BAND IN ZR-84
- 1995
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 75:8, s. 1471-1474
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Zr-84 were studied using the early implementation phase of the Gammasphere array and the ''Microball'' charged-particle detector system. A cascade of nine gamma rays with a dynamic moment of inertia which is characteristic of superdeformed rotational bands in the A = 80 region has been identified and assigned to Zr-84. The measured transition quadrupole moment of the band corresponds to a prolate quadrupole deformation of beta(2) = 0.53 and confirms the superdeformed nature of this band. This is the first direct experimental confirmation of the existence of the predicted superdeformed shell gap at N similar or equal to 44 particle number.
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| 10. |
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