| 1. |
- Joss, D T, et al.
(författare)
-
Lifetime measurements of a triaxial band in Ce-133
- 1998
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 58:6, s. 3219-3222
-
Tidskriftsartikel (refereegranskat)abstract
- Lifetimes of states within a triaxial band belonging to;the gamma-soft nucleus Ce-133 have been determined through a Doppler-broadened line shape analysis. A value, Q(t)approximate to 2.2 eb, has been found for the transition quadrupole moment which is considerably smaller than that of superdeformed structures (Q(t)approximate to 7.4 e b) in this mass region. The results are discussed in terms of deformation self-consistent calculations based on the total Routhian surface formalism. [S0556-2813(98)01912-8].
|
|
| 2. |
- Perries, S, et al.
(författare)
-
Decay-out of the yrast superdeformed band in Nd-136 : Towards an experimental extraction of the neutron pairing gap at large deformation
- 1999
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 60:6
-
Tidskriftsartikel (refereegranskat)abstract
- A study of the Nd-136 nucleus has been performed with the EUROBALL III multidetector to establish the decay-out of the yrast superdeformed (SD) band. Three discrete linking transitions (754, 1456, and 1493 keV) have been discovered, establishing the position of the SD band at 7.03 MeV excitation energy with proposed spin and parity 17((-)) for the lowest observed SD state. Neutron pairing gap parameters for SD shapes have been extracted in Nd isotopes, using the strong-coupling model and odd-even mass difference formulas. The major conclusion of our phenomenological analysis is that the pairing correlations do subsist in the SD configurations of nuclei in the A = 130 mass region. [S0556-2813(99)01312-6].
|
|
| 3. |
- Asztalos, S J, et al.
(författare)
-
Spin yields of neutron-rich nuclei from deep inelastic reactions
- 1999
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 60:4
-
Tidskriftsartikel (refereegranskat)abstract
- The potential for using deep inelastic reactions to populate high-spin states in neutron-rich nuclei is studied in a series of experiments using GAMMASPHERE for gamma-ray detection and a silicon strip detector for measuring the angles of projectilelike and targetlike fragments. In three experiments 61 new transitions up to a maximum spin of 22 (h) over bar in 12 neutron-rich rare-earth nuclei were found. We observe that gamma-ray yields as a function of spin are flatter for all neutron transfer products than for inelastic excitation of either the projectile or target nucleus. Calculations are presented which indicate that this difference cannot be accounted for by quasielastic processes, but more likely are the result of larger energy loss processes, such as deep inelastic reactions. [S0556-2813(99)06009-4].
|
|
| 4. |
- Baldsiefen, G, et al.
(författare)
-
Shears bands in Pb-193
- 1996
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 54:3, s. 1106-1116
-
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.
|
|
| 5. |
- BERNSTEIN, LA, et al.
(författare)
-
ONSET OF COLLECTIVITY IN NEUTRON-DEFICIENT PO-196,PO-198
- 1995
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 52:2, s. 621-627
-
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.
|
|
| 6. |
- BERNSTEIN, LA, et al.
(författare)
-
SUPERDEFORMATION IN ER-154
- 1995
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 52:3, s. R1171-R1174
-
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.
|
|
| 7. |
- Brinkman, M J, et al.
(författare)
-
Decay from a superdeformed band in Pb-194
- 1996
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:4, s. R1461-R1464
-
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.
|
|
| 8. |
|
|
| 9. |
- Clark, R M, et al.
(författare)
-
Superdeformation in bismuth
- 1996
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:1, s. 117-123
-
Tidskriftsartikel (refereegranskat)abstract
- High angular momentum states in Bi-195-197 are populated in two reactions: W-183(F-19,xn)Bi-202-x and Ta-181(Ne-20,xn)Bi-201-x at beam energies of 108 and 123 MeV, respectively. Gamma rays were detected using the Gammasphere array. Three weakly populated rotational sequences have been found. They each have properties characteristic of other superdeformed bands in this mass region. On the basis of cross-bombardment information we believe that one band belongs to each of Bi-195, Bi-196, and Bi-197. The properties of the bands in the odd-Bi nuclei are best reproduced if the odd proton occupies the favored signature of the [651]1/2 orbital, while the band in Bi-196 has this same proton configuration coupled to an additional N=7 (j(15/2)) neutron. The relative behavior of the J((2)) moments of inertia can be qualitatively understood in terms of Pauli-blocking effects.
|
|
| 10. |
- CLARK, RM, et al.
(författare)
-
SUPERDEFORMATION IN THE BISMUTH NUCLEI
- 1995
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 51:3, s. R1052-R1056
-
Tidskriftsartikel (refereegranskat)
|
|
