Excitation energy dependence of fragment-mass distributions from fission of 180,190Hg formed in fusion reactions of 36Ar + 144,154Sm

K. Nishio; A. N. Andreyev; R. Chapman; X. Derkx; Ch E. Düllmann; L. Ghys; F. P. Heßberger; K. Hirose; H. Ikezoe; J. Khuyagbaatar; B. Kindler; B. Lommel; H. Makii; I. Nishinaka; T. Ohtsuki; S. D. Pain; R. Sagaidak; I. Tsekhanovich; M. Venhart; Y. Wakabayashi; S. Yan

doi:10.1016/j.physletb.2015.06.068

Excitation energy dependence of fragment-mass distributions from fission of ^180,190Hg formed in fusion reactions of ³⁶Ar + ^144,154Sm

K. Nishio, A. N. Andreyev, R. Chapman, X. Derkx, Ch E. Düllmann, L. Ghys, F. P. Heßberger, K. Hirose, H. Ikezoe, J. Khuyagbaatar, B. Kindler, B. Lommel, H. Makii, I. Nishinaka, T. Ohtsuki, S. D. Pain, R. Sagaidak, I. Tsekhanovich, M. Venhart, Y. WakabayashiS. Yan

Nuclear Structure and Nuclear Astrophysi

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

54 Scopus citations

Abstract

Mass distributions of fission fragments from the compound nuclei ¹⁸⁰Hg and ¹⁹⁰Hg formed in fusion reactions ³⁶Ar + ¹⁴⁴Sm and ³⁶Ar + ¹⁵⁴Sm, respectively, were measured at initial excitation energies of E*(Hg180)=33-66 MeV and E*(Hg190)=48-71 MeV. In the fission of ¹⁸⁰Hg, the mass spectra were well reproduced by assuming only an asymmetric-mass division, with most probable light and heavy fragment masses A-L/A-H=79/101. The mass asymmetry for ¹⁸⁰Hg agrees well with that obtained in the low-energy β⁺/EC-delayed fission of ¹⁸⁰Tl, from our earlier ISOLDE(CERN) experiment. Fission of ¹⁹⁰Hg is found to proceed in a similar way, delivering the mass asymmetry of A-L/A-H=83/107, throughout the measured excitation energy range. The persistence as a function of excitation energy of the mass-asymmetric fission for both proton-rich Hg isotopes gives strong evidence for the survival of microscopic effects up to effective excitation energies of compound nuclei as high as 40 MeV. This behavior is different from fission of actinide nuclei and heavier mercury isotope ¹⁹⁸Hg.

Original language	English
Pages (from-to)	89-94
Number of pages	6
Journal	Physics Letters B
Volume	748
DOIs	https://doi.org/10.1016/j.physletb.2015.06.068
State	Published - Sep 2 2015

Funding

The authors thank the staff of the JAEA-tandem facility for the beam operation and the GSI target laboratory for preparation of the Sm targets. Special thanks for extensive discussions of calculated FFs mass distributions are due to Drs. P. Möller and J. Randrup. Support from the University of Bordeaux (France) in the framework of the IdEx program is gratefully acknowledged. The work was supported by the Science and Technology Facilities Council (STFC), United Kingdom, and by the FWO-Vlaanderen , Belgium.

Funders	Funder number
FWO-Vlaanderen
Science and Technology Facilities Council	ST/J000183/2, ST/L005727/1, ST/L005808/1
Japan Society for the Promotion of Science	25400304

Keywords

Fusion-fission
Hg
Mass asymmetric fission

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10.1016/j.physletb.2015.06.068

Cite this

Nishio, K., Andreyev, A. N., Chapman, R., Derkx, X., Düllmann, C. E., Ghys, L., Heßberger, F. P., Hirose, K., Ikezoe, H., Khuyagbaatar, J., Kindler, B., Lommel, B., Makii, H., Nishinaka, I., Ohtsuki, T., Pain, S. D., Sagaidak, R., Tsekhanovich, I., Venhart, M., ... Yan, S. (2015). Excitation energy dependence of fragment-mass distributions from fission of ^180,190Hg formed in fusion reactions of ³⁶Ar + ^144,154Sm. Physics Letters B, 748, 89-94. https://doi.org/10.1016/j.physletb.2015.06.068

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title = "Excitation energy dependence of fragment-mass distributions from fission of 180,190Hg formed in fusion reactions of 36Ar + 144,154Sm",

abstract = "Mass distributions of fission fragments from the compound nuclei 180Hg and 190Hg formed in fusion reactions 36Ar + 144Sm and 36Ar + 154Sm, respectively, were measured at initial excitation energies of E*(Hg180)=33-66 MeV and E*(Hg190)=48-71 MeV. In the fission of 180Hg, the mass spectra were well reproduced by assuming only an asymmetric-mass division, with most probable light and heavy fragment masses A-L/A-H=79/101. The mass asymmetry for 180Hg agrees well with that obtained in the low-energy β+/EC-delayed fission of 180Tl, from our earlier ISOLDE(CERN) experiment. Fission of 190Hg is found to proceed in a similar way, delivering the mass asymmetry of A-L/A-H=83/107, throughout the measured excitation energy range. The persistence as a function of excitation energy of the mass-asymmetric fission for both proton-rich Hg isotopes gives strong evidence for the survival of microscopic effects up to effective excitation energies of compound nuclei as high as 40 MeV. This behavior is different from fission of actinide nuclei and heavier mercury isotope 198Hg.",

keywords = "Fusion-fission, Hg, Mass asymmetric fission",

author = "K. Nishio and Andreyev, {A. N.} and R. Chapman and X. Derkx and D{\"u}llmann, {Ch E.} and L. Ghys and He{\ss}berger, {F. P.} and K. Hirose and H. Ikezoe and J. Khuyagbaatar and B. Kindler and B. Lommel and H. Makii and I. Nishinaka and T. Ohtsuki and Pain, {S. D.} and R. Sagaidak and I. Tsekhanovich and M. Venhart and Y. Wakabayashi and S. Yan",

note = "Publisher Copyright: {\textcopyright} 2015 The Authors.",

year = "2015",

month = sep,

day = "2",

doi = "10.1016/j.physletb.2015.06.068",

language = "English",

volume = "748",

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Nishio, K, Andreyev, AN, Chapman, R, Derkx, X, Düllmann, CE, Ghys, L, Heßberger, FP, Hirose, K, Ikezoe, H, Khuyagbaatar, J, Kindler, B, Lommel, B, Makii, H, Nishinaka, I, Ohtsuki, T, Pain, SD, Sagaidak, R, Tsekhanovich, I, Venhart, M, Wakabayashi, Y & Yan, S 2015, 'Excitation energy dependence of fragment-mass distributions from fission of ^180,190Hg formed in fusion reactions of ³⁶Ar + ^144,154Sm', Physics Letters B, vol. 748, pp. 89-94. https://doi.org/10.1016/j.physletb.2015.06.068

TY - JOUR

T1 - Excitation energy dependence of fragment-mass distributions from fission of 180,190Hg formed in fusion reactions of 36Ar + 144,154Sm

AU - Nishio, K.

AU - Andreyev, A. N.

AU - Chapman, R.

AU - Derkx, X.

AU - Düllmann, Ch E.

AU - Ghys, L.

AU - Heßberger, F. P.

AU - Hirose, K.

AU - Ikezoe, H.

AU - Khuyagbaatar, J.

AU - Kindler, B.

AU - Lommel, B.

AU - Makii, H.

AU - Nishinaka, I.

AU - Ohtsuki, T.

AU - Pain, S. D.

AU - Sagaidak, R.

AU - Tsekhanovich, I.

AU - Venhart, M.

AU - Wakabayashi, Y.

AU - Yan, S.

PY - 2015/9/2

Y1 - 2015/9/2

N2 - Mass distributions of fission fragments from the compound nuclei 180Hg and 190Hg formed in fusion reactions 36Ar + 144Sm and 36Ar + 154Sm, respectively, were measured at initial excitation energies of E*(Hg180)=33-66 MeV and E*(Hg190)=48-71 MeV. In the fission of 180Hg, the mass spectra were well reproduced by assuming only an asymmetric-mass division, with most probable light and heavy fragment masses A-L/A-H=79/101. The mass asymmetry for 180Hg agrees well with that obtained in the low-energy β+/EC-delayed fission of 180Tl, from our earlier ISOLDE(CERN) experiment. Fission of 190Hg is found to proceed in a similar way, delivering the mass asymmetry of A-L/A-H=83/107, throughout the measured excitation energy range. The persistence as a function of excitation energy of the mass-asymmetric fission for both proton-rich Hg isotopes gives strong evidence for the survival of microscopic effects up to effective excitation energies of compound nuclei as high as 40 MeV. This behavior is different from fission of actinide nuclei and heavier mercury isotope 198Hg.

AB - Mass distributions of fission fragments from the compound nuclei 180Hg and 190Hg formed in fusion reactions 36Ar + 144Sm and 36Ar + 154Sm, respectively, were measured at initial excitation energies of E*(Hg180)=33-66 MeV and E*(Hg190)=48-71 MeV. In the fission of 180Hg, the mass spectra were well reproduced by assuming only an asymmetric-mass division, with most probable light and heavy fragment masses A-L/A-H=79/101. The mass asymmetry for 180Hg agrees well with that obtained in the low-energy β+/EC-delayed fission of 180Tl, from our earlier ISOLDE(CERN) experiment. Fission of 190Hg is found to proceed in a similar way, delivering the mass asymmetry of A-L/A-H=83/107, throughout the measured excitation energy range. The persistence as a function of excitation energy of the mass-asymmetric fission for both proton-rich Hg isotopes gives strong evidence for the survival of microscopic effects up to effective excitation energies of compound nuclei as high as 40 MeV. This behavior is different from fission of actinide nuclei and heavier mercury isotope 198Hg.

KW - Fusion-fission

KW - Hg

KW - Mass asymmetric fission

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U2 - 10.1016/j.physletb.2015.06.068

DO - 10.1016/j.physletb.2015.06.068

M3 - Article

AN - SCOPUS:84936888983

SN - 0370-2693

VL - 748

SP - 89

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JO - Physics Letters B

JF - Physics Letters B

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