New systematic features in the neutron-deficient Au isotopes

M Venhart ,A V Podshibyakin ,R D Page ,R Urban ,A Patel ,C Unsworth ,J Kliman ,J Lušnák ,D T Joss ,Š Motyčák ,L Makhathini ,L J Harkness-Brennan ,D S Judson ,Michael P Balogh ,A Špaček ,Andrew Boston ,V Matoušek ,T E Cocolios ,J Klimo ,P M Prajapati ,John L Wood ,А М Родин ,Л Крупа ,R.‐D Herzberg ,Martin Sedlák ,L Holub ,M Bírová ,Kristian Petrík ,M Veselský

doi:10.1088/1361-6471/aa7297

Abstract

A recently developed portable, on-line capability for γ-ray and conversion-electron spectroscopy, HIGH-TATRA is demonstrated with its application to the study of 183Hg 183Au at ISOLDE. Key details of the low-energy level scheme of the neutron-deficient nuclide 183Au populated in this decay are presented. A broad energy germanium detector is employed to achieve this (the first-ever use of such a device in decay-scheme spectroscopy), by way of a combination of high-gain γ-ray singles spectroscopy and γ–γ coincidence spectroscopy. Further, by combining the γ-ray detectors with a liquid-nitrogen-cooled Si(Li) detector operated under high vacuum, conversion-electron singles and e–γ coincidences are obtained. These data lead to the determination of transition multipolarities and the location of a highly converted (E0 + M1 + E2) transition in the 183Au decay scheme, suggesting a possible new shape coexisting structure in this nucleus. Identification of new intruder and normal states fixes their relative energies in 183Au for the first time. New systematic features in the odd-Au isotopes are presented.

Highlights

A major strategic theme that has been overarching to the study of nuclear structure far from stability is the elucidation of systematic features of selected properties of nuclei: masses; charge radii; properties of the first few excited states; properties of states with specified spinparity
In this work we use a technique which we have developed in [32] in conjunction with the presently reported study to make an advance in addressing this issue by the use of a modern broad energy germanium detectors (BEGe) [29] detector with high energy resolution over a broad energy range, operated at high gain and in coincidence mode
It is interesting to note that the isotopes where the intruder state becomes the ground state correspond to nuclei for which the mean-square charge radius has been observed to depart suddenly from the trend set by the heavier isotopes

Summary

Introduction

A major strategic theme that has been overarching to the study of nuclear structure far from stability is the elucidation of systematic features of selected properties of nuclei: masses; charge radii; properties of the first few excited states; properties of states with specified spinparity. One particular feature of nuclei whose observation has depended heavily on systematic study is the phenomenon of shape coexistence in nuclei. In the present account we give details of an on-going quest to elucidate the nature of shape coexistence in the neutron deficient Pt, Au, Hg, Tl, Pb, Bi, Po region with special focus on the odd-mass Au isotopes. Shape coexistence in the neutron-deficient Au isotopes and their neighbours

Results

Discussion

Conclusion