High-spin states, lifetime measurements and isomers in Os-181

DM Cullen, LK Pattison, JF Smith, AM Fletcher, PM Walker, HM El-Masri, Z Podolyak, RJ Wood, C Scholey, C Wheldon, G Mukherjee, D Balabanski, M Djongolov, T Dalsgaard, Helge Thisgaard, G Sletten, F Kondev, D Jenkins, GD Dracoulis, GJ LaneIY Lee, AO Macchiavelli, F Xu

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The level scheme of Os-181(76) has been investigated with the Nd-150(S-36,5n) reaction. The low-K rotational bands built upon the 9/2(+)[624], 7/2(-)[514] and 1/2(-)[521] neutron configurations have been extended and other new bands established. The configurations of these low-K bands are discussed within the framework of the cranked-shell model. The lifetimes for some of the states in the 9/2(+) [624] and 1/2(-) [521] collective rotational bands were also measured using the Doppler Shift Attenuation method. The large deformations deduced are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These results support the idea that for these low-K states the nuclear shape is axially symmetric and allows the K quantum number to be defined and the associated K-selection rule to be upheld. This behaviour apparently contrasts with that of the higher-K states in Os-181. In the higher-spin regime, two new high-K intrinsic states, with K-pi = 37/2(+) and K-pi 41/2(+), were established, along with the fragmented decay of a K-pi = 33/2(-) intrinsic state. The configurations and excitation energies of these experimentally determined intrinsic states are found to be in excellent agreement with theoretical calculations based on a fixed shape Nilsson model plus BCS pairing. The structures on top of these intrinsic states do, however, show very different behaviour. A relatively regular high-K rotational band was observed on top of the K-pi = 41/2(+) state but not for the other newly-established intrinsic states. Theoretical configuration-constrained potential energy surface calculations suggest that the irregular transition sequence above the K-pi = 37/2(+) intrinsic bandhead state, the limited excitations observed above the other intrinsic states and the observation of fragmented and non-hindered decays, are due to these configurations being subject to an appreciable gamma softness. These calculations reveal that the K-pi = 41/2(+) configuration is less susceptible to distortions in the gamma plane than any of the other high-K states. (C) 2003 Elsevier B.V. All fights reserved.
OriginalsprogEngelsk
TidsskriftNuclear Physics A: Nuclear and Hadronic Physics
Vol/bind728
Udgave nummer3-4
Sider (fra-til)287-338
ISSN0375-9474
DOI
StatusUdgivet - 15. dec. 2003
Udgivet eksterntJa

Citer dette

Cullen, DM., Pattison, LK., Smith, JF., Fletcher, AM., Walker, PM., El-Masri, HM., ... Xu, F. (2003). High-spin states, lifetime measurements and isomers in Os-181. Nuclear Physics A: Nuclear and Hadronic Physics, 728(3-4), 287-338. https://doi.org/10.1016/j.nuclphysa.2003.09.001
Cullen, DM ; Pattison, LK ; Smith, JF ; Fletcher, AM ; Walker, PM ; El-Masri, HM ; Podolyak, Z ; Wood, RJ ; Scholey, C ; Wheldon, C ; Mukherjee, G ; Balabanski, D ; Djongolov, M ; Dalsgaard, T ; Thisgaard, Helge ; Sletten, G ; Kondev, F ; Jenkins, D ; Dracoulis, GD ; Lane, GJ ; Lee, IY ; Macchiavelli, AO ; Xu, F. / High-spin states, lifetime measurements and isomers in Os-181. I: Nuclear Physics A: Nuclear and Hadronic Physics. 2003 ; Bind 728, Nr. 3-4. s. 287-338.
@article{9fa26e17918a46fda688d7ec3e575463,
title = "High-spin states, lifetime measurements and isomers in Os-181",
abstract = "The level scheme of Os-181(76) has been investigated with the Nd-150(S-36,5n) reaction. The low-K rotational bands built upon the 9/2(+)[624], 7/2(-)[514] and 1/2(-)[521] neutron configurations have been extended and other new bands established. The configurations of these low-K bands are discussed within the framework of the cranked-shell model. The lifetimes for some of the states in the 9/2(+) [624] and 1/2(-) [521] collective rotational bands were also measured using the Doppler Shift Attenuation method. The large deformations deduced are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These results support the idea that for these low-K states the nuclear shape is axially symmetric and allows the K quantum number to be defined and the associated K-selection rule to be upheld. This behaviour apparently contrasts with that of the higher-K states in Os-181. In the higher-spin regime, two new high-K intrinsic states, with K-pi = 37/2(+) and K-pi 41/2(+), were established, along with the fragmented decay of a K-pi = 33/2(-) intrinsic state. The configurations and excitation energies of these experimentally determined intrinsic states are found to be in excellent agreement with theoretical calculations based on a fixed shape Nilsson model plus BCS pairing. The structures on top of these intrinsic states do, however, show very different behaviour. A relatively regular high-K rotational band was observed on top of the K-pi = 41/2(+) state but not for the other newly-established intrinsic states. Theoretical configuration-constrained potential energy surface calculations suggest that the irregular transition sequence above the K-pi = 37/2(+) intrinsic bandhead state, the limited excitations observed above the other intrinsic states and the observation of fragmented and non-hindered decays, are due to these configurations being subject to an appreciable gamma softness. These calculations reveal that the K-pi = 41/2(+) configuration is less susceptible to distortions in the gamma plane than any of the other high-K states. (C) 2003 Elsevier B.V. All fights reserved.",
author = "DM Cullen and LK Pattison and JF Smith and AM Fletcher and PM Walker and HM El-Masri and Z Podolyak and RJ Wood and C Scholey and C Wheldon and G Mukherjee and D Balabanski and M Djongolov and T Dalsgaard and Helge Thisgaard and G Sletten and F Kondev and D Jenkins and GD Dracoulis and GJ Lane and IY Lee and AO Macchiavelli and F Xu",
year = "2003",
month = "12",
day = "15",
doi = "10.1016/j.nuclphysa.2003.09.001",
language = "English",
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pages = "287--338",
journal = "Nuclear Physics A: Nuclear and Hadronic Physics",
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Cullen, DM, Pattison, LK, Smith, JF, Fletcher, AM, Walker, PM, El-Masri, HM, Podolyak, Z, Wood, RJ, Scholey, C, Wheldon, C, Mukherjee, G, Balabanski, D, Djongolov, M, Dalsgaard, T, Thisgaard, H, Sletten, G, Kondev, F, Jenkins, D, Dracoulis, GD, Lane, GJ, Lee, IY, Macchiavelli, AO & Xu, F 2003, 'High-spin states, lifetime measurements and isomers in Os-181', Nuclear Physics A: Nuclear and Hadronic Physics, bind 728, nr. 3-4, s. 287-338. https://doi.org/10.1016/j.nuclphysa.2003.09.001

High-spin states, lifetime measurements and isomers in Os-181. / Cullen, DM; Pattison, LK; Smith, JF; Fletcher, AM; Walker, PM; El-Masri, HM; Podolyak, Z; Wood, RJ; Scholey, C; Wheldon, C; Mukherjee, G; Balabanski, D; Djongolov, M; Dalsgaard, T; Thisgaard, Helge; Sletten, G; Kondev, F; Jenkins, D; Dracoulis, GD; Lane, GJ; Lee, IY; Macchiavelli, AO; Xu, F.

I: Nuclear Physics A: Nuclear and Hadronic Physics, Bind 728, Nr. 3-4, 15.12.2003, s. 287-338.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - High-spin states, lifetime measurements and isomers in Os-181

AU - Cullen, DM

AU - Pattison, LK

AU - Smith, JF

AU - Fletcher, AM

AU - Walker, PM

AU - El-Masri, HM

AU - Podolyak, Z

AU - Wood, RJ

AU - Scholey, C

AU - Wheldon, C

AU - Mukherjee, G

AU - Balabanski, D

AU - Djongolov, M

AU - Dalsgaard, T

AU - Thisgaard, Helge

AU - Sletten, G

AU - Kondev, F

AU - Jenkins, D

AU - Dracoulis, GD

AU - Lane, GJ

AU - Lee, IY

AU - Macchiavelli, AO

AU - Xu, F

PY - 2003/12/15

Y1 - 2003/12/15

N2 - The level scheme of Os-181(76) has been investigated with the Nd-150(S-36,5n) reaction. The low-K rotational bands built upon the 9/2(+)[624], 7/2(-)[514] and 1/2(-)[521] neutron configurations have been extended and other new bands established. The configurations of these low-K bands are discussed within the framework of the cranked-shell model. The lifetimes for some of the states in the 9/2(+) [624] and 1/2(-) [521] collective rotational bands were also measured using the Doppler Shift Attenuation method. The large deformations deduced are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These results support the idea that for these low-K states the nuclear shape is axially symmetric and allows the K quantum number to be defined and the associated K-selection rule to be upheld. This behaviour apparently contrasts with that of the higher-K states in Os-181. In the higher-spin regime, two new high-K intrinsic states, with K-pi = 37/2(+) and K-pi 41/2(+), were established, along with the fragmented decay of a K-pi = 33/2(-) intrinsic state. The configurations and excitation energies of these experimentally determined intrinsic states are found to be in excellent agreement with theoretical calculations based on a fixed shape Nilsson model plus BCS pairing. The structures on top of these intrinsic states do, however, show very different behaviour. A relatively regular high-K rotational band was observed on top of the K-pi = 41/2(+) state but not for the other newly-established intrinsic states. Theoretical configuration-constrained potential energy surface calculations suggest that the irregular transition sequence above the K-pi = 37/2(+) intrinsic bandhead state, the limited excitations observed above the other intrinsic states and the observation of fragmented and non-hindered decays, are due to these configurations being subject to an appreciable gamma softness. These calculations reveal that the K-pi = 41/2(+) configuration is less susceptible to distortions in the gamma plane than any of the other high-K states. (C) 2003 Elsevier B.V. All fights reserved.

AB - The level scheme of Os-181(76) has been investigated with the Nd-150(S-36,5n) reaction. The low-K rotational bands built upon the 9/2(+)[624], 7/2(-)[514] and 1/2(-)[521] neutron configurations have been extended and other new bands established. The configurations of these low-K bands are discussed within the framework of the cranked-shell model. The lifetimes for some of the states in the 9/2(+) [624] and 1/2(-) [521] collective rotational bands were also measured using the Doppler Shift Attenuation method. The large deformations deduced are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These results support the idea that for these low-K states the nuclear shape is axially symmetric and allows the K quantum number to be defined and the associated K-selection rule to be upheld. This behaviour apparently contrasts with that of the higher-K states in Os-181. In the higher-spin regime, two new high-K intrinsic states, with K-pi = 37/2(+) and K-pi 41/2(+), were established, along with the fragmented decay of a K-pi = 33/2(-) intrinsic state. The configurations and excitation energies of these experimentally determined intrinsic states are found to be in excellent agreement with theoretical calculations based on a fixed shape Nilsson model plus BCS pairing. The structures on top of these intrinsic states do, however, show very different behaviour. A relatively regular high-K rotational band was observed on top of the K-pi = 41/2(+) state but not for the other newly-established intrinsic states. Theoretical configuration-constrained potential energy surface calculations suggest that the irregular transition sequence above the K-pi = 37/2(+) intrinsic bandhead state, the limited excitations observed above the other intrinsic states and the observation of fragmented and non-hindered decays, are due to these configurations being subject to an appreciable gamma softness. These calculations reveal that the K-pi = 41/2(+) configuration is less susceptible to distortions in the gamma plane than any of the other high-K states. (C) 2003 Elsevier B.V. All fights reserved.

U2 - 10.1016/j.nuclphysa.2003.09.001

DO - 10.1016/j.nuclphysa.2003.09.001

M3 - Journal article

VL - 728

SP - 287

EP - 338

JO - Nuclear Physics A: Nuclear and Hadronic Physics

JF - Nuclear Physics A: Nuclear and Hadronic Physics

SN - 0375-9474

IS - 3-4

ER -

Cullen DM, Pattison LK, Smith JF, Fletcher AM, Walker PM, El-Masri HM et al. High-spin states, lifetime measurements and isomers in Os-181. Nuclear Physics A: Nuclear and Hadronic Physics. 2003 dec 15;728(3-4):287-338. https://doi.org/10.1016/j.nuclphysa.2003.09.001