1. |
- BERNSTEIN, LA, et al.
(author)
-
ONSET OF COLLECTIVITY IN NEUTRON-DEFICIENT PO-196,PO-198
- 1995
-
In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 52:2, s. 621-627
-
Journal article (peer-reviewed)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.
|
|
2. |
|
|
3. |
- Cederwall, Bo, et al.
(author)
-
MEASUREMENT OF ULTRA-FAST GAMMA-RAY TRANSITIONS FROM HEAVY-ION COMPOUND NUCLEUS REACTIONS
- 1995
-
In: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 354:2-3, s. 591-594
-
Journal article (peer-reviewed)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.
|
|
4. |
- Cederwall, Bo, et al.
(author)
-
PROPERTIES OF SUPERDEFORMED BANDS IN DY-153
- 1995
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 346:3-4, s. 244-250
-
Journal article (peer-reviewed)abstract
- Two new superdeformed (SD) bands in Dy-153, in addition to the three previously observed, have been studied with the GAMMASPHERE detector array. Assignments to single-neutron orbits in the SD potential are made based on the band properties. Evidence for a band interaction at very high spins, possibly involving the first N = 7 proton intruder orbital, is observed in the strongest populated SD band. Furthermore, evidence far a Delta I = 2 staggering is also found in this SD band.
|
|
5. |
- CLARK, RM, et al.
(author)
-
A PAIR OF IDENTICAL SUPERDEFORMED BANDS IN ND-136
- 1995
-
In: Physics Letters B. - 0370-2693 .- 1873-2445. ; 343:1-4, s. 59-63
-
Journal article (peer-reviewed)abstract
- High-spin states in Nd-136 were populated via the Mo-100(Ar-40, 4n) reaction at beam energies of 176 and 182 MeV, and resulting gamma-rays were detected using the GAMMASPHERE spectrometer. Analysis of the data has revealed the existence of an excited superdeformed (SD) band in Nd-136. Th, yrast SD band in Nd-136 has been extended by the addition of four (possibly five) transitions at high frequency. The new band displays the remarkable property of having transition energies identical (to within +/- 1 keV) to those of the half-points of the yrast SD band of Nd-136. Possible explanations in terms of cranked Woods-Saxon single-particle calculations are discussed.
|
|
6. |
- DELEPLANQUE, MA, et al.
(author)
-
LOW-SPIN TERMINATION OF THE SUPERDEFORMED BAND IN ND-135
- 1995
-
In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 52:5, s. R2302-R2305
-
Journal article (peer-reviewed)abstract
- The decay of the superdeformed (SD) band in Nd-135 was studied with the early implementation of gamma-sphere. The results suggest that the SD band ''terminates'' at spin 25/2. This termination is explained by a change of the SD minimum toward a triaxial lower deformation. Ultimate cranker calculations with the i(13/2) orbital occupied relate this change to a shift of a proton and neutron pair out of deformation-driving Nilsson orbitals. This is a completely new and unexpected mechanism for the decay of SD bands.
|
|
7. |
|
|
8. |
|
|
9. |
- JIN, HQ, et al.
(author)
-
IDENTIFICATION AND QUADRUPOLE-MOMENT MEASUREMENT OF A SUPERDEFORMED BAND IN ZR-84
- 1995
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 75:8, s. 1471-1474
-
Journal article (peer-reviewed)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.
|
|