Shape coexistence and fission in the lead region studied by in-source laser spectroscopy at RILIS-ISOLDE (A. Andreyev)
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Asia/Tokyo
Nishina Hall (RIKEN Wako)
Nishina Hall
RIKEN Wako
Description
Title: Shape coexistence and fission in the lead region studied by in-source laser spectroscopy at RILIS-ISOLDE
Date: May 27, 2013 Time: 15:00 – Place: Nishina hall
Lecturer: A. Andreyev
Abstract:
The competition between spherical and deformed nuclear shapes at low energy gives rise to shape coexistence in the region of the neutron-deficient lead isotopes with Z~82 and N~104 [1]. In order to determine to which extend the ground and/or isomeric states of those and neighboring nuclides are affected by this phenomenon, an extended campaign of investigation of changes in the mean-square charge radii is on-going at ISOLDE. By combining the high sensitivity of the in-source laser spectroscopy technique, ISOLDE mass separation and Windmill alpha-decay spec-troscopy setup [2], it has been possible to study long isotopic chains of lead [3] and polonium [4], down to N=100 and N=107 respectively, and, recently, thallium isotopic chain down to N=98 [5], see Figure. In this contribution, we will present the systematics of charge radii in thallium isotopes [5] together with the first preliminary results of the 2012 experimental campaign at ISOLDE to study charge radii in the long chains of the astatine and lightest gold isotopes [6]. In the gold and astatine cases, next to Faraday cup and Windmill measurements, also the Multi-Reflection Time-of-Flight (MR-ToF) mass separation technique [7] involving the ISOLTRAP collaboration was used.
In the second part of the talk, an overview of the recent beta-delayed fission studies at ISOLDE in the lead region will also be presented.
References
[1] K.Heyde and J. Wood. Rev. Mod. Physics 83, 1467 (2011)
[2] A.N. Andreyev et al,, Phys. Rev. Lett. 105, 252502,(2010)
[3] H. De Witte et al., Phys. Rev. Lett. 98, 112502 (2007)
[4] T.E. Cocolios et al., Phys. Rev. Lett. 106, 052503 (2011)
[5] A.N. Andreyev, A. Barzakh et al., IS511 experiment at ISOLDE (2012)
[6] A.N. Andreyev, V. Fedosseev, P. Van Duppen et al., IS534 experiment at ISOLDE (2012)
[7] R. N. Wolf et al., Nucl. Instr. and Meth. A 686, 82-90 (2012)
