| 1. |
- Vogt, A., et al.
(författare)
-
Isomers and high-spin structures in the N=81 isotones Xe-135 and Ba-137
- 2017
-
Ingår i: PHYSICAL REVIEW C. - : AMER PHYSICAL SOC. - 2469-9985. ; 95:2
-
Tidskriftsartikel (refereegranskat)abstract
- The high-spin structures and isomers of the N = 81 isotones Xe-135 and Ba-137 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in Xe-136+ U-238 and (ii) Xe-136+ Pb-208 MNT reactions employing the high-resolution Advanced Gamma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (iii) in the Xe-136+ Pt-198 MNT reaction employing the gamma-ray array GAMMASPHERE in combination with the gas-detector array CHICO, and (iv) via a B-11+ Te-130 fusion-evaporation reaction with the HORUS gamma-ray array at the University of Cologne. The high-spin level schemes of Xe-135 and Ba-137 are considerably extended to higher energies. The 2058-keV (19/2(-)) state in Xe-135 is identified as an isomer, closing a gap in the systematics along the N = 81 isotones. Its half-life is measured to be 9.0(9) ns, corresponding to a reduced transition probability of B(E2,19/2(-) -> 15/2(-)) = 0.52(6) W.u. The experimentally deduced reduced transition probabilities of the isomeric states are compared to shell-model predictions. Latest shell-model calculations reproduce the experimental findings generally well and provide guidance to the interpretation of the new levels.
|
|
| 2. |
- Vogt, A., et al.
(författare)
-
High-spin structure of Xe-134
- 2016
-
Ingår i: PHYSICAL REVIEW C. - 2469-9985. ; 93:5
-
Tidskriftsartikel (refereegranskat)abstract
- Detailed spectroscopic information on the N similar to 82 nuclei is necessary to benchmark shell-model calculations in the region. The nuclear structure above long-lived isomers in Xe-134 is investigated after multinucleon transfer (MNT) and actinide fission. Xenon-134 was populated as (i) a transfer product in Xe-136 + U-238 and Xe-136 + Pb-208 MNT reactions and (ii) as a fission product in the Xe-136 + U-238 reaction employing the high-resolution Advanced Gamma Tracking Array (AGATA). Trajectory reconstruction has been applied for the complete identification of beamlike transfer products with the magnetic spectrometer PRISMA. The Xe-136 + Pt-198 MNT reaction was studied with the gamma-ray spectrometer GAMMASPHERE in combination with the gas detector array Compact Heavy Ion Counter (CHICO). Several high-spin states in Xe-134 on top of the two long-lived isomers are discovered based on gamma gamma-coincidence relationships and information on the gamma-ray angular distributions as well as excitation energies from the total kinetic energy loss and fission fragments. The revised level scheme of Xe-134 is extended up to an
|
|
| 3. |
- Syndikus, I., et al.
(författare)
-
Probing the Z = 6 spin-orbit shell gap with (p,2p) quasi-free scattering reactions
- 2020
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 809
-
Tidskriftsartikel (refereegranskat)abstract
- The evolution of the traditional nuclear magic numbers away from the valley of stability is an active field of research. Experimental efforts focus on providing key spectroscopic information that will shed light into the structure of exotic nuclei and understanding the driving mechanism behind the shell evolution. In this work, we investigate the Z=6 spin-orbit shell gap towards the neutron dripline. To do so, we employed NA(p,2p)CA−1 quasi-free scattering reactions to measure the proton component of the 21+ state of 16,18,20C. The experimental findings support the notion of a moderate reduction of the proton 1p1/2−1p3/2 spin-orbit splitting, at variance to recent claims for a prevalent Z=6 magic number towards the neutron dripline.
|
|
| 4. |
- Riley, M A, et al.
(författare)
-
Beyond band termination in Er-157 and the search for wobbling excitations in strongly deformed Hf-174
- 2005
-
Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. 1735-1740
-
Tidskriftsartikel (refereegranskat)abstract
- High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of special terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work the high-spin structure of Er-157 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently, four strongly or superdeformed (SD) sequences have been observed in Hf-174 and ultimate cranker calculations predict, such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment was run to search for linking transitions between the SD bands and possible wobbling modes.
|
|
| 5. |
- Riley, M. A., et al.
(författare)
-
Observation of states beyond band termination in Er-156,Er-157,Er-158 and strongly deformed structures in Hf-173,Hf-174,Hf-175
- 2006
-
Ingår i: Physica Scripta. - 0031-8949. ; T125, s. 123-126
-
Tidskriftsartikel (refereegranskat)abstract
- High-spin terminating bands in heavy nuclei were first identified in nuclei around Er-158(90). While examples of terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work, the high-spin structure of Er-156,Er-157,Er-158 has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently four strongly or superdeformed (SD) sequences have been observed in Hf-174, and cranking calculations using the Ultimate Cranker code predict that such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment took place to search for linking transitions between the SD bands, possible wobbling modes, and new SD band structures.
|
|
| 6. |
- Simpson, J., et al.
(författare)
-
Evolution of structure and shapes in Er 158 to ultrahigh spin
- 2023
-
Ingår i: Physical Review C. - 2469-9985. ; 107:5
-
Tidskriftsartikel (refereegranskat)abstract
- The level structure of Er158 has been studied using the Gammasphere spectrometer via the Cd114(Ca48,4n) reaction at 215 MeV with both thin (self-supporting) and thick (backed) targets. The level scheme has been considerably extended with more than 200 new transitions and six new rotational structures, including two strongly coupled high-K bands. Configuration assignments for the new structures are based on their observed alignments, B(M1)/B(E2) ratios of reduced transition probabilities, excitation energies, and comparisons with neighboring nuclei and theoretical calculations. With increasing angular momentum, this nucleus exhibits Coriolis-induced alignments of both neutrons and protons before it then undergoes a rotation-induced transition from near-prolate collective rotation to a noncollective oblate configuration. This transition occurs via the mechanism of band termination around spin 45ħ in three rotational structures. Two distinct lifetime branches, consistent with the crossing of a collective "fast"rotational structure by an energetically favored "slow"terminating sequence, are confirmed for the positive-parity states, and similar behavior is established in the negative-parity states. Weak-intensity, high-energy transitions are observed to feed into the terminating states. At the highest spins, three collective bands with high dynamic moments of inertia and large quadrupole moments were identified. These bands are interpreted as triaxial strongly deformed structures and mark a return to collectivity at ultrahigh spin.
|
|
| 7. |
- 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.
|
|
| 8. |
- Gates, J. M., et al.
(författare)
-
Decay Spectroscopy of Element 115 Daughters: 280Rg -> 276Mt and 276Mt -> 272Bh
- 2015
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 92:2
-
Tidskriftsartikel (refereegranskat)abstract
- Forty-six decay chains, assigned to the decay of 288-115, were produced using the 243Am(48Ca,3n)288-115 reaction at the Lawrence Berkeley National Laboratory 88-in. cyclotron. The resulting series of α decays were studied using α-photon and α-x-ray spectroscopies. Multiple α-photon coincidences were observed in the element 115 decay chain members, particularly in the third- and fourth-generation decays (presumed to be 280Rg and 276Mt, respectively). Upon combining these data with those from 22 288-115 decay chains observed in a similar experiment, updated level schemes in 276Mt and 272Bh (populated by the α decay of 280Rg and 276Mt, respectively) are proposed. Photons were observed in the energy range expected for K x rays coincident with the α decay of both 280Rg and 276Mt. However, Compton scattering of higher-energy γ rays and discrete transitions are present in the K x-ray region preventing a definitive Z identification to be made based on observation of characteristic K x-ray energies.
|
|
| 9. |
- 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.
|
|
| 10. |
- Evans, A. O., et al.
(författare)
-
Magnetic properties of deformed dipole bands in Te-110,Te-112
- 2006
-
Ingår i: Physica Scripta. - 0031-8949. ; T125, s. 192-193
-
Tidskriftsartikel (refereegranskat)abstract
- A lifetime analysis using the Doppler-shift attenuation method has been performed on the Tellurium isotopes Te-110,Te-112. The experiment was performed using the Gammasphere array in conjunction with the MICROBALL charged-particle detector. Three strongly coupled bands were previously established in Te-110,Te-112 which were observed up to unusually high spins. In the current experiment, it has been possible to extract lifetime measurements using a Doppler broadened lineshape analysis on one of the Delta I = 1 band structures in Te-110. In contrast to similar Delta I = 1 structures in other nuclei in this mass region, the extracted B(M1) values did not rapidly decrease with increasing angular momentum. Instead, the strongly coupled band in Te-110 represents a deformed 1p-1h structure, rather than a weakly deformed structure showing the shears mechanism.
|
|
| 11. |
- Paul, E. S., et al.
(författare)
-
Smooth terminating bands in Te-112: Particle-hole induced collectivity
- 2007
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 75:1
-
Tidskriftsartikel (refereegranskat)abstract
- The Gammasphere spectrometer, in conjunction with the Microball charged-particle array, was used to investigate high-spin states in Te-112 via Ni-58(Ni-58, 4p gamma) reactions at 240 and 250 MeV. Several smooth terminating bands were established, and lifetime measurements were performed for the strongest one using the Doppler-shift attenuation method. Results obtained in the spin range 18-32h yield a transition quadrupole moment of 4.0 +/- 0.5eb, which corresponds to a quadrupole deformation epsilon(2)=0.26 +/- 0.03; this value is significantly larger than the ground-state deformation of tellurium isotopes. It was also possible to extract a transition quadrupole moment for the yrast band in Xe-114, produced via the 58Ni (58Ni, 2p gamma) reaction. A value of 3.0 +/- 0.5eb was found in the spin range 16-24h, which corresponds to a quadrupole deformation epsilon(2)=0.19 +/- 0.03. Cranked Nilsson-Strutinsky calculations are used to interpret the results.
|
|
| 12. |
- 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].
|
|
| 13. |
- 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.
|
|
| 14. |
- Lauritsen, T., et al.
(författare)
-
Characterization of a gamma-ray tracking array : A comparison of GRETINA and Gammasphere using a 60Co source
- 2016
-
Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 836, s. 46-56
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we provide a formalism for the characterization of tracking arrays with emphasis on the proper corrections required to extract their photopeak efficiencies and peak-to-total ratios. The methods are first applied to Gammasphere, a well characterized 4π array based on the principle of Compton suppression, and subsequently to GRETINA. The tracking efficiencies are then discussed and some guidelines as to what clustering angle to use in the tracking algorithm are presented. It was possible, using GEANT4 simulations, to scale the measured efficiencies up to the expected values for the full 4π implementation of GRETA.
|
|
| 15. |
- McNabb, D P, et al.
(författare)
-
Superdeformation in Po-198
- 1996
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 53:2, s. R541-R543
-
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.
|
|
| 16. |
- Paul, E. S., et al.
(författare)
-
Loss of collectivity in the transitional Er-156 nucleus at high spin
- 2009
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 79:4
-
Tidskriftsartikel (refereegranskat)abstract
- The Cd-114(Ca-48, 6n gamma) reaction at 215 MeV has been investigated using the Gammasphere spectrometer to study the high-spin structure of the nucleus Er-156(68)88. Many new transitions have been established along with 68 definitive spin-parity level assignments from a high-fold angular-distribution analysis. In addition, absolute B(M 1) and B(E 1) strengths have been inferred from measured gamma-ray branching ratios. Strong B(E 1) strength (10(-3) W.u.) is discussed in terms of possible octupole collectivity at low spin. At high spin, this nucleus undergoes a Coriolis-induced shape transition from a prolate state of collective rotation to a noncollective, triaxial-oblate configuration. The yrast positive-parity structure ultimately terminates in an energetically favored oblate state at I-pi = 42(+). Several weak high-energy gamma-ray transitions have been discovered that feed this favored state. State-of-the-art cranked Nilsson-Strutinsky calculations are used to interpret the high-spin behavior of Er-156 and comparisons are made with other N = 88 isotones.
|
|
| 17. |
- Paul, E. S., et al.
(författare)
-
Return of collective rotation in Er-157 and Er-158 at ultrahigh spin
- 2007
-
Ingår i: Physical Review Letters. - 1079-7114. ; 98:1, s. 1-012501
-
Tidskriftsartikel (refereegranskat)abstract
- A new frontier of discrete-line gamma-ray spectroscopy at ultrahigh spin has been opened in the rare-earth nuclei Er-157,Er-158. Four rotational structures, displaying high moments of inertia, have been identified, which extend up to spin similar to 65h and bypass the band-terminating states in these nuclei which occur at similar to 45h. Cranked Nilsson-Strutinsky calculations suggest that these structures arise from well-deformed triaxial configurations that lie in a valley of favored shell energy which also includes the triaxial strongly deformed bands in Lu161-167.
|
|
| 18. |
- Petri, M., et al.
(författare)
-
Structure of C-16: Testing shell model and ab initio approaches
- 2012
-
Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:4, s. Art. no. 044329-
-
Tidskriftsartikel (refereegranskat)abstract
- Excited states in C-16 were populated via the Be-9(N-17,C-16+gamma)X one-proton knockout reaction. The lifetime of the 2(1)(+) state in C-16 was measured using the recoil distance method. The extracted lifetime of tau(+)(21) = 11.4(-0.9)(+0.8)(stat) +/- 0.7(syst(B rho))(-1.5)(+0.0)(syst(feeding)) ps yields a deduced B(E2;2(1)(+) -> 0(1)(+)) = 4.21(-0.26)(+0.34)(stat)(-0.24)(+0.28)(syst(B rho))(-0.00)(+0.64)(syst(feeding)) e(2)fm(4) value in good agreement with a previous measurement. The one-proton knockout cross section is used to extract the proton amplitude of the C-16 2(1)(+) state, which confirms the neutron dominant character of this state. Gamma-ray branching ratios between the 2(2)(+) state and the 2(1)(+) and ground states were also determined. The results are compared with p-sd shell model and no-core shell model (with NN and NN + NNN) calculations. The inclusion of three-body forces are essential in order for the no-core shell model calculations to reproduce the experimental findings on the gamma-ray branching ratios.
|
|
| 19. |
- Riley, M. A., et al.
(författare)
-
Strongly Deformed Nuclear Shapes at Ultra-High Spin and Shape Coexistence in N\sim 90 Nuclei
- 2009
-
Ingår i: Acta Physica Polonica B. - 0587-4254. ; 40:3, s. 513-522
-
Tidskriftsartikel (refereegranskat)abstract
- The N similar to 90 region of the nuclear chart has featured prominently as the spectroscopy of nuclei at extreme spin has progressed. This talk will present recent discoveries from investigations of high spin behavior in the N similar to 90 Er, Tm and Yb nuclei utilizing the Gammasphere gamma-ray spectrometer. In particular it will include discussion of the beautiful shape evolution and coexistence observed in these nuclei along with the identification of a remarkable new family of band structures. The latter are very weakly populated rotational sequences with high moment of inertia that bypass the classic terminating configurations near spin 40-50 (h) over bar, marking a return to collectivity that extends discrete gamma-ray spectroscopy to well over 60 (h) over bar. Establishing the nature of the yrast states in these nuclei beyond the oblate band-termination states has been a major goal for the past two decades. Cranking calculations suggest that these new structures most likely represent stable triaxial strongly deformed bands that lie in a valley of favored shell energy in deformation and particle-number space.
|
|
| 20. |
- Svensson, C. E., et al.
(författare)
-
Collective rotational motion in the N=Z nucleus 36Ar
- 2001
-
Ingår i: Nuclear Physics A. - 0375-9474. ; 682:1-4, s. 1-11
-
Tidskriftsartikel (refereegranskat)abstract
- A superdeformed rotational band has been identified in the N = Z nucleus 36Ar, firmly linked to known low-spin states, and observed to its high-spin termination at Iπ = 16+. Lifetime measurements by the Doppler shift attenuation method establish a large low-spin deformation (β2 ≈ 0.46) and a decrease in the collectivity as the band approaches termination. Comparisons with cranked Nilsson-Strutinsky and large-scale spherical shell model calculations lead to a consistent description of the band based on a configuration in which four particles are promoted to the pf shell. With two major shells active for both protons and neutrons, yet a valence space dimension small enough to be approached from the shell model perspective, this band offers an excellent opportunity to investigate the microscopic structure of collective rotational motion in nuclei.
|
|
| 21. |
- Svensson, C. E., et al.
(författare)
-
Decay Out of the Doubly Magic Superdeformed Band in the N=Z Nucleus 60Zn
- 1999
-
Ingår i: Physical Review Letters. - 1079-7114. ; 82:17, s. 3400-3403
-
Tidskriftsartikel (refereegranskat)abstract
- The doubly magic superdeformed band in the N = Z nucleus Zn-60 has been identified. Linking transitions connecting this band to the yrast line provide the first spin, parity, and excitation energy measurements for superdeformed states in the A similar to 60 region. The stretched-E2 character and relatively large B(E2) values of these transitions suggest a nonstatistical decay-out process.
|
|
| 22. |
- Svensson, C. E., et al.
(författare)
-
Superdeformation in the N = z Nucleus 36Ar : Experimental, deformed mean field, and spherical shell model descriptions
- 2000
-
Ingår i: Physical Review Letters. - 0031-9007. ; 85:13, s. 2693-2696
-
Tidskriftsartikel (refereegranskat)abstract
- A superdeformed rotational band has been identified in 36Ar, linked to known low-spin states, and observed to its high-spin termination at Iπ = 16+. Cranked Nilsson-Strutinsky and spherical shell model calculations assign the band to a configuration in which four pf-shell orbitals are occupied, leading to a low-spin deformation β2 ≈ 0.45. Two major shells are active for both protons and neutrons, yet the valence space remains small enough to be confronted with the shell model. This band thus provides an ideal case to study the microscopic structure of collective rotational motion.
|
|
| 23. |
- Ward, D., et al.
(författare)
-
Band Structure of 68Ge
- 2001
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 63:1
-
Tidskriftsartikel (refereegranskat)abstract
- The nucleus Ge-68 has been studied by gamma-ray spectroscopy following its population at high spin in the reaction Ca-40(S-32,4p) Ge-68. The reaction channel was selected with the Microball array and gamma rays were detected with the Gammasphere array. The level scheme is very complex, reflecting the many different, and presumably mixed, excitation modes in this nucleus. Nevertheless, there appear to be some simplifications in the spin range above 18 (h) over bar where we have identified a superdeformed band and several terminating bands. The results are compared with a cranked Nilsson-Strutinsky model without pairing.
|
|
| 24. |
- Karlgren, Daniel, et al.
(författare)
-
High-angular-momentum structures in Zn-64
- 2004
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 69, s. 1-034330
-
Tidskriftsartikel (refereegranskat)abstract
- High-angular-momentum states in Zn-64 were populated in the Ca-40(Si-28,4p) reaction at a beam energy of 122 MeV. Evaporated, light, charged particles were identified by the Microball, while gamma rays were detected using the Gammasphere array. The main focus of this paper is on two strongly coupled, collective bands. The yrast band, which was previously known, has been linked to lower-lying states establishing the excitation energies and angular momenta of in-band states for the first time. The newly identified excited band decays to the yrast band but firm angular-momentum assignments could not be made. In order to interpret these structures cranked-Nilsson-Strutinsky calculations have been performed. The calculations have been extended to account for the distribution of nucleons within a configuration. The yrast collective band is interpreted as based on the pi(f(7/2))(-1)(p(3/2)f(5/2))(2)(g(9/2))(1)nu(p(3/2)f(5/2))(4)(g(9/2))(2) configuration. There are several possible interpretations of the second band but it is difficult to distinguish between the different possibilities.
|
|
| 25. |
- Nag, Somnath, et al.
(författare)
-
Collective and noncollective states in (120)Te
- 2012
-
Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 85:1
-
Tidskriftsartikel (refereegranskat)abstract
- High-spin states in (120)Te were populated in the reaction (80)Se((48)Ca, alpha 4n)(120)Te at a beam energy of 207 MeV and gamma-ray coincidences were measured using the Gammasphere spectrometer. The previously known level scheme is extended to higher spin and new interband transitions and side-feeding branches are established. Five highly deformed rotational bands, extending up to almost I = 50, are observed for the first time. The bands are compared with similar structures found recently in neighboring nuclei. The experimental results are interpreted within the framework of the cranked Nilsson-Strutinsky model. Configuration assignments to several terminating states and to the high-spin bands are discussed.
|
|
