报告题目：Shape coexistence in gold, mercury and bismuth isotopic chains
studied by in-source laser spectroscopy at RILIS-ISOLDE
报告人：Prof. Andrei Andreyev
（Department of Physics, University of York, UK
Advanced Science Research Center, Japan Atomic Energy Agency, Tokai-mura, Japan）
报告时间：2019年8月19日（周一）上午10点
报告地点：北京大学加速器楼402会议室
联系人：杨晓菲（xiaofei.yang@pku.edu.cn）
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Abstract:
The size and the shape are among the most important properties of atomic nuclei. The competition between spherical and deformed nuclear configurations at low energy gives rise to shape coexistence in the neutron-deficient isotopes around Z~82 and N~104 [1]. The most notorious case is the shape staggering in the Hg isotopes, first observed about 45 years ago [2].
An extended experimental campaign to study the mean-square charge radii of the ground and isomeric states of these nuclides is being conducted at ISOLDE by the RILIS-Windmill-ISOLTRAP-IDS collaboration. The measurements rely on the high sensitivity achieved by combining in-source laser resonance ionization spectroscopy, ISOLDE mass separation, the Windmill spectroscopy setup [3], the Multi-Reflection Time-of-Flight (MR-ToF) mass separation technique [4], and the ISOLDE Decay Station (IDS) [5].
In this talk, the systematics of charge radii and electromagnetic moments recently obtained by our collaboration at ISOLDE for the long isotopic chains of Au (IS534), Hg (IS598) and Bi isotopes (IS608) will be presented. These three chains demonstrate striking similarities in the shape staggering and shape changes when approaching the neutron mid-shell at N=104, while the lightest Au and Hg isotopes show the strong tendency towards the smooth nearly-spherical behavior.
[1] K. Heyde and J. Wood, Rev. Mod. Phys. 83, 1467 (2011).
[2] J. Bonn, G. Huber, H.-J. Kluge, L. Kugler, and E. Otten, Phys. Lett. B 38, 308 (1972).
[3] A.N. Andreyev et al, Phys. Rev. Lett. 105, 252502,(2010).
[4] R. N. Wolf et al., Nucl. Instr. and Meth. A 686, 82-90 (2012).
[5] IDS collaboration, http://isolde-ids.web.cern.ch/isolde-ids/ (2017).
Biography:
1. Graduated from Moscow State University (Physics Department)
2. Worked for 9 years in Flerov Lab for Nuclear Reactions, JINR, Dubna
3. Then, a series of post-docs at GSI, Leuven, University of Liverpool, TRIUMF, back to Leuven as a visiting professor,
then - a professor in Paisley, University of Scotland (Scotland), and last 7 years - a professor at the University of York.
A head of the group at JAEA (Tokai-mura, Japan), since last 7 years.
