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

D. M. Cullen; L. K. Pattison; J. F. Smith; A. M. Fletcher; P. M. Walker; H. M. El-Masri; Zs Podolyák; R. J. Wood; C. Scholey; C. Wheldon; G. Mukherjee; D. Balabanski; M. Djongolov; Th Dalsgaard; H. Thisgaard; G. Sletten; F. Kondev; D. Jenkins; G. D. Dracoulis; G. J. Lane; I. Y. Lee; A. O. Macchiavelli; F. Xu

doi:10.1016/j.nuclphysa.2003.09.001

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

D. M. Cullen^*, L. K. Pattison, J. F. Smith, A. M. Fletcher, P. M. Walker, H. M. El-Masri, Zs Podolyák, R. J. Wood, C. Scholey, C. Wheldon, G. Mukherjee, D. Balabanski, M. Djongolov, Th Dalsgaard, H. Thisgaard, G. Sletten, F. Kondev, D. Jenkins, G. D. Dracoulis, G. J. LaneI. Y. Lee, A. O. Macchiavelli, F. Xu

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

The level scheme of ¹⁸¹ ₇₆ Os has been investigated with the ¹⁵⁰ Nd( ³⁶ S,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 ¹⁸¹ Os.In the higher-spin regime, two new high-K intrinsic states, with K ^π =37/2 ⁺ and K ^π =41/2 ⁺ , were established, along with the fragmented decay of a K ^π =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 ^π =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 ^π =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 γ softness. These calculations reveal that the K ^π =41/2 ⁺ configuration is less susceptible to distortions in the γ plane than any of the other high-K states.

Original language	English
Pages (from-to)	287-338
Number of pages	52
Journal	Nuclear Physics A
Volume	728
Issue number	3-4
DOIs	https://doi.org/10.1016/j.nuclphysa.2003.09.001
Publication status	Published - 15 Dec 2003

Keywords

Os deduced high-spin levels, J, π, configurations, T , quadrupole moments
Cranked shell-model analysis
DSA
E=160 MeV
Gammasphere array
measured Eγ, Iγ, γγ-coin
Nuclear reactions Nd( S,5n)

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10.1016/j.nuclphysa.2003.09.001

Cite this

Cullen, D. M., Pattison, L. K., Smith, J. F., Fletcher, A. M., Walker, P. M., El-Masri, H. M., Podolyák, Z., Wood, R. J., Scholey, C., Wheldon, C., Mukherjee, G., Balabanski, D., Djongolov, M., Dalsgaard, T., Thisgaard, H., Sletten, G., Kondev, F., Jenkins, D., Dracoulis, G. D., ... Xu, F. (2003). High-spin states, lifetime measurements and isomers in ¹⁸¹ Os. Nuclear Physics A, 728(3-4), 287-338. https://doi.org/10.1016/j.nuclphysa.2003.09.001

@article{96ed19903f6742c0be5b4869f11b5192,

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

abstract = " The level scheme of 181 76 Os has been investigated with the 150 Nd( 36 S,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 181 Os.In the higher-spin regime, two new high-K intrinsic states, with K π =37/2 + and K π =41/2 + , were established, along with the fragmented decay of a K π =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 π =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 π =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 γ softness. These calculations reveal that the K π =41/2 + configuration is less susceptible to distortions in the γ plane than any of the other high-K states.",

keywords = "Os deduced high-spin levels, J, π, configurations, T , quadrupole moments, Cranked shell-model analysis, DSA, E=160 MeV, Gammasphere array, measured Eγ, Iγ, γγ-coin, Nuclear reactions Nd( S,5n)",

author = "Cullen, {D. M.} and Pattison, {L. K.} and Smith, {J. F.} and Fletcher, {A. M.} and Walker, {P. M.} and El-Masri, {H. M.} and Zs Podoly{\'a}k and Wood, {R. J.} and C. Scholey and C. Wheldon and G. Mukherjee and D. Balabanski and M. Djongolov and Th Dalsgaard and H. Thisgaard and G. Sletten and F. Kondev and D. Jenkins and Dracoulis, {G. D.} and Lane, {G. J.} and Lee, {I. Y.} and Macchiavelli, {A. O.} and F. Xu",

year = "2003",

month = dec,

day = "15",

doi = "10.1016/j.nuclphysa.2003.09.001",

language = "English",

volume = "728",

pages = "287--338",

journal = "Nuclear Physics A",

issn = "0375-9474",

publisher = "Elsevier",

number = "3-4",

}

Cullen, DM, Pattison, LK, Smith, JF, Fletcher, AM, Walker, PM, El-Masri, HM, Podolyák, 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 ¹⁸¹ Os', Nuclear Physics A, vol. 728, no. 3-4, pp. 287-338. https://doi.org/10.1016/j.nuclphysa.2003.09.001

TY - JOUR

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

AU - Cullen, D. M.

AU - Pattison, L. K.

AU - Smith, J. F.

AU - Fletcher, A. M.

AU - Walker, P. M.

AU - El-Masri, H. M.

AU - Podolyák, Zs

AU - Wood, R. J.

AU - Scholey, C.

AU - Wheldon, C.

AU - Mukherjee, G.

AU - Balabanski, D.

AU - Djongolov, M.

AU - Dalsgaard, Th

AU - Thisgaard, H.

AU - Sletten, G.

AU - Kondev, F.

AU - Jenkins, D.

AU - Dracoulis, G. D.

AU - Lane, G. J.

AU - Lee, I. Y.

AU - Macchiavelli, A. O.

AU - Xu, F.

PY - 2003/12/15

Y1 - 2003/12/15

N2 - The level scheme of 181 76 Os has been investigated with the 150 Nd( 36 S,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 181 Os.In the higher-spin regime, two new high-K intrinsic states, with K π =37/2 + and K π =41/2 + , were established, along with the fragmented decay of a K π =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 π =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 π =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 γ softness. These calculations reveal that the K π =41/2 + configuration is less susceptible to distortions in the γ plane than any of the other high-K states.

AB - The level scheme of 181 76 Os has been investigated with the 150 Nd( 36 S,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 181 Os.In the higher-spin regime, two new high-K intrinsic states, with K π =37/2 + and K π =41/2 + , were established, along with the fragmented decay of a K π =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 π =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 π =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 γ softness. These calculations reveal that the K π =41/2 + configuration is less susceptible to distortions in the γ plane than any of the other high-K states.

KW - Os deduced high-spin levels, J, π, configurations, T , quadrupole moments

KW - Cranked shell-model analysis

KW - DSA

KW - E=160 MeV

KW - Gammasphere array

KW - measured Eγ, Iγ, γγ-coin

KW - Nuclear reactions Nd( S,5n)

UR - http://www.scopus.com/inward/record.url?scp=0142219396&partnerID=8YFLogxK

U2 - 10.1016/j.nuclphysa.2003.09.001

DO - 10.1016/j.nuclphysa.2003.09.001

M3 - Article

AN - SCOPUS:0142219396

SN - 0375-9474

VL - 728

SP - 287

EP - 338

JO - Nuclear Physics A

JF - Nuclear Physics A

IS - 3-4

ER -

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

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Keywords

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