Andel, B, Andreyev, AN, Antalic, S, Al Monthery, M, Barzakh, A, Bissell, ML, Chrysalidis, K, Cocolios, TE, Cubiss, JG, Day Goodacre, T et al (show 26 more authors)
(2020)
β-delayed fission of isomers in 188Bi.
Physical Review C, 102 (1).
014319-.
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Andel et al. - 2020 - Physical Review C - β-delayed fission of isomers in 188Bi.pdf - Published version Download (1MB) | Preview |
Abstract
β-delayed fission (βDF) decay of a low-spin (ls) and a high-spin (hs) isomer in Bi188 was studied at the ISOLDE facility at CERN. Isomer-selective laser ionization and time gating were employed to investigate each isomer separately and their βDF partial half-lives were determined: T1/2p,βDF(188Bihs)=5.6(8)×103 s and T1/2p,βDF(188Bils)=1.7(6)×103 s. This work is the first βDF study of two states in one isotope and allows the spin dependence of low-energy fission to be explored. The fission fragment mass distribution of a daughter nuclide Pb188, following the β decay of the high-spin isomer, was deduced and indicates a mixture of symmetric and asymmetric fission modes. Experimental results were compared with self-consistent mean-field calculations based on the finite-range Gogny D1M interaction. To reproduce the measured T1/2p,βDF(188Bihs), the calculated fission barrier of Pb188 had to be reduced by ≈30%. After this reduction, the measured T1/2p,βDF(188Bils) was in agreement with calculations for a few possible configurations for Bils188. Theoretical βDF probabilities for these configurations were found to be lower by a factor of 4-9 than the βDF probability of Bihs188. The fission fragment mass distribution of Pb188 was compared to the scission-point model SPY and the calculations based on the finite-range liquid-drop model. The first observation of βDF for Bi190 is also reported.
| Item Type: | Article |
|---|---|
| Depositing User: | Symplectic Admin |
| Date Deposited: | 28 Aug 2020 08:31 |
| Last Modified: | 15 Mar 2024 15:38 |
| DOI: | 10.1103/physrevc.102.014319 |
| Related URLs: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3098824 |
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