Abstract
α-decay spectroscopy of Tl has been performed at the CERN isotope separator on-line (ISOLDE) facility. New fine-structure α decays have been observed for both isotopes. α-decay branching ratios of 0.089(19)%, 0.047(6)% and 1.22(30)% have been deduced for the (10-), (7+) and (2-) states respectively in 184Tl and a lower limit of 0.49% for the α-decay branching ratio of 182Tl. A new half-life of 9.5(2) s for the (2-) state in 184Tl and 1.9(1) s for the low-spin state in 182Tl has been deduced. Using α-γ coincidence analysis, multiple γ rays were observed de-exciting levels in Au fed by Tl α decays. The γ transitions connecting these low-lying states in Au are essential to sort the data and possibly identify bands from in-beam studies in these isotopes. Owing to the complex fine-structure α decays and limited knowledge about the structure of the daughter nuclei, only partial level schemes could be constructed for both gold isotopes in the present work. Reduced α-decay widths have been calculated and are compared with values obtained in neighboring odd-A and even-A thallium isotopes. Except for the allowed α decay of the 184Tl (10-) state, the other fine-structure α decays observed in this study are hindered. This points to strong structural changes between parent thallium and daughter gold isotopes.
Original language | English |
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Article number | 025102 |
Journal | Journal of Physics G: Nuclear and Particle Physics |
Volume | 43 |
Issue number | 2 |
DOIs | |
Publication status | Published - 8 Jan 2016 |
Keywords
- intruder states
- isomerism
- shape coexistence
- α-spectroscopy