Collectivity in the light radon nuclei measured directly via Coulomb excitation

L. P. Gaffney; A. P. Robinson; D. G. Jenkins; A. N. Andreyev; M. Bender; A. Blazhev; N. Bree; B. Bruyneel; P. A. Butler; T. E. Cocolios; T. Davinson; A. N. Deacon; H. De Witte; D. Dijulio; J. Diriken; A. Ekström; Ch Fransen; S. J. Freeman; K. Geibel; T. Grahn; B. Hadinia; M. Hass; P. H. Heenen; H. Hess; M. Huyse; U. Jakobsson; N. Kesteloot; J. Konki; Th Kröll; V. Kumar; O. Ivanov; S. Martin-Haugh; D. Mücher; R. Orlandi; J. Pakarinen; A. Petts; P. Peura; P. Rahkila; P. Reiter; M. Scheck; M. Seidlitz; K. Singh; J. F. Smith; J. Van De Walle; P. Van Duppen; D. Voulot; R. Wadsworth; N. Warr; F. Wenander; K. Wimmer; K. Wrzosek-Lipska; M. Zielińska

doi:10.1103/PhysRevC.91.064313

Collectivity in the light radon nuclei measured directly via Coulomb excitation

L. P. Gaffney^*, A. P. Robinson, D. G. Jenkins, A. N. Andreyev, M. Bender, A. Blazhev, N. Bree, B. Bruyneel, P. A. Butler, T. E. Cocolios, T. Davinson, A. N. Deacon, H. De Witte, D. Dijulio, J. Diriken, A. Ekström, Ch Fransen, S. J. Freeman, K. Geibel, T. GrahnB. Hadinia, M. Hass, P. H. Heenen, H. Hess, M. Huyse, U. Jakobsson, N. Kesteloot, J. Konki, Th Kröll, V. Kumar, O. Ivanov, S. Martin-Haugh, D. Mücher, R. Orlandi, J. Pakarinen, A. Petts, P. Peura, P. Rahkila, P. Reiter, M. Scheck, M. Seidlitz, K. Singh, J. F. Smith, J. Van De Walle, P. Van Duppen, D. Voulot, R. Wadsworth, N. Warr, F. Wenander, K. Wimmer, K. Wrzosek-Lipska, M. Zielińska

^*Corresponding author for this work

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

Abstract

Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z=82 and the neutron midshell at N=104. Purpose: Evidence for shape coexistence has been inferred from α-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn202 and Rn204 were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E2) matrix element connecting the ground state and first excited 21+ state was extracted for both Rn202 and Rn204, corresponding to B(E2;21+→01+)=29-8+8 and 43-12+17 W.u., respectively. Additionally, E2 matrix elements connecting the 21+ state with the 41+ and 22+ states were determined in Rn202. No excited 0+ states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced.

Original language	English
Article number	064313
Journal	Physical Review C
Volume	91
Issue number	6
DOIs	https://doi.org/10.1103/PhysRevC.91.064313
Publication status	Published - 22 Jun 2015

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10.1103/PhysRevC.91.064313

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Gaffney, L. P., Robinson, A. P., Jenkins, D. G., Andreyev, A. N., Bender, M., Blazhev, A., Bree, N., Bruyneel, B., Butler, P. A., Cocolios, T. E., Davinson, T., Deacon, A. N., De Witte, H., Dijulio, D., Diriken, J., Ekström, A., Fransen, C., Freeman, S. J., Geibel, K., ... Zielińska, M. (2015). Collectivity in the light radon nuclei measured directly via Coulomb excitation. Physical Review C, 91(6), Article 064313. https://doi.org/10.1103/PhysRevC.91.064313

@article{d45d63b51e8f44b082be5790532ebaac,

title = "Collectivity in the light radon nuclei measured directly via Coulomb excitation",

abstract = "Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z=82 and the neutron midshell at N=104. Purpose: Evidence for shape coexistence has been inferred from α-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn202 and Rn204 were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E2) matrix element connecting the ground state and first excited 21+ state was extracted for both Rn202 and Rn204, corresponding to B(E2;21+→01+)=29-8+8 and 43-12+17 W.u., respectively. Additionally, E2 matrix elements connecting the 21+ state with the 41+ and 22+ states were determined in Rn202. No excited 0+ states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced.",

author = "Gaffney, {L. P.} and Robinson, {A. P.} and Jenkins, {D. G.} and Andreyev, {A. N.} and M. Bender and A. Blazhev and N. Bree and B. Bruyneel and Butler, {P. A.} and Cocolios, {T. E.} and T. Davinson and Deacon, {A. N.} and {De Witte}, H. and D. Dijulio and J. Diriken and A. Ekstr{\"o}m and Ch Fransen and Freeman, {S. J.} and K. Geibel and T. Grahn and B. Hadinia and M. Hass and Heenen, {P. H.} and H. Hess and M. Huyse and U. Jakobsson and N. Kesteloot and J. Konki and Th Kr{\"o}ll and V. Kumar and O. Ivanov and S. Martin-Haugh and D. M{\"u}cher and R. Orlandi and J. Pakarinen and A. Petts and P. Peura and P. Rahkila and P. Reiter and M. Scheck and M. Seidlitz and K. Singh and Smith, {J. F.} and {Van De Walle}, J. and {Van Duppen}, P. and D. Voulot and R. Wadsworth and N. Warr and F. Wenander and K. Wimmer and K. Wrzosek-Lipska and M. Zieli{\'n}ska",

year = "2015",

month = jun,

day = "22",

doi = "10.1103/PhysRevC.91.064313",

language = "English",

volume = "91",

journal = "Physical Review C",

issn = "2469-9985",

publisher = "American Physical Society",

number = "6",

}

Gaffney, LP, Robinson, AP, Jenkins, DG , Andreyev, AN, Bender, M, Blazhev, A, Bree, N, Bruyneel, B, Butler, PA, Cocolios, TE, Davinson, T, Deacon, AN, De Witte, H, Dijulio, D, Diriken, J, Ekström, A, Fransen, C, Freeman, SJ, Geibel, K, Grahn, T, Hadinia, B, Hass, M, Heenen, PH, Hess, H, Huyse, M, Jakobsson, U, Kesteloot, N, Konki, J, Kröll, T, Kumar, V, Ivanov, O, Martin-Haugh, S, Mücher, D, Orlandi, R, Pakarinen, J, Petts, A, Peura, P, Rahkila, P, Reiter, P, Scheck, M, Seidlitz, M, Singh, K, Smith, JF, Van De Walle, J, Van Duppen, P, Voulot, D, Wadsworth, R, Warr, N, Wenander, F, Wimmer, K, Wrzosek-Lipska, K & Zielińska, M 2015, 'Collectivity in the light radon nuclei measured directly via Coulomb excitation', Physical Review C, vol. 91, no. 6, 064313. https://doi.org/10.1103/PhysRevC.91.064313

TY - JOUR

T1 - Collectivity in the light radon nuclei measured directly via Coulomb excitation

AU - Gaffney, L. P.

AU - Robinson, A. P.

AU - Jenkins, D. G.

AU - Andreyev, A. N.

AU - Bender, M.

AU - Blazhev, A.

AU - Bree, N.

AU - Bruyneel, B.

AU - Butler, P. A.

AU - Cocolios, T. E.

AU - Davinson, T.

AU - Deacon, A. N.

AU - De Witte, H.

AU - Dijulio, D.

AU - Diriken, J.

AU - Ekström, A.

AU - Fransen, Ch

AU - Freeman, S. J.

AU - Geibel, K.

AU - Grahn, T.

AU - Hadinia, B.

AU - Hass, M.

AU - Heenen, P. H.

AU - Hess, H.

AU - Huyse, M.

AU - Jakobsson, U.

AU - Kesteloot, N.

AU - Konki, J.

AU - Kröll, Th

AU - Kumar, V.

AU - Ivanov, O.

AU - Martin-Haugh, S.

AU - Mücher, D.

AU - Orlandi, R.

AU - Pakarinen, J.

AU - Petts, A.

AU - Peura, P.

AU - Rahkila, P.

AU - Reiter, P.

AU - Scheck, M.

AU - Seidlitz, M.

AU - Singh, K.

AU - Smith, J. F.

AU - Van De Walle, J.

AU - Van Duppen, P.

AU - Voulot, D.

AU - Wadsworth, R.

AU - Warr, N.

AU - Wenander, F.

AU - Wimmer, K.

AU - Wrzosek-Lipska, K.

AU - Zielińska, M.

PY - 2015/6/22

Y1 - 2015/6/22

N2 - Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z=82 and the neutron midshell at N=104. Purpose: Evidence for shape coexistence has been inferred from α-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn202 and Rn204 were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E2) matrix element connecting the ground state and first excited 21+ state was extracted for both Rn202 and Rn204, corresponding to B(E2;21+→01+)=29-8+8 and 43-12+17 W.u., respectively. Additionally, E2 matrix elements connecting the 21+ state with the 41+ and 22+ states were determined in Rn202. No excited 0+ states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced.

AB - Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z=82 and the neutron midshell at N=104. Purpose: Evidence for shape coexistence has been inferred from α-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn202 and Rn204 were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E2) matrix element connecting the ground state and first excited 21+ state was extracted for both Rn202 and Rn204, corresponding to B(E2;21+→01+)=29-8+8 and 43-12+17 W.u., respectively. Additionally, E2 matrix elements connecting the 21+ state with the 41+ and 22+ states were determined in Rn202. No excited 0+ states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced.

UR - http://www.scopus.com/inward/record.url?scp=84936791410&partnerID=8YFLogxK

U2 - 10.1103/PhysRevC.91.064313

DO - 10.1103/PhysRevC.91.064313

M3 - Article

SN - 2469-9985

VL - 91

JO - Physical Review C

JF - Physical Review C

IS - 6

M1 - 064313

ER -

Collectivity in the light radon nuclei measured directly via Coulomb excitation

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Collectivity in the light radon nuclei measured directly via Coulomb excitation

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