Identification of excited states in Bi188 and Po188

• Published in: Physical review. C 2022-08, Vol.106 (2)
• Main Authors: Zhang, W. Q., Andreyev, Andrei N., Liu, Z., Seweryniak, D., Huang, H., Li, Z. H., Li, J. G., Guo, C. Y., Barzakh, A. E., Van Duppen, P., Al Monthery, M., Andel, B., Antalic, S., Block, M., Bronis, A., Carpenter, M. P., Copp, P., Cubiss, J. G., Ding, B., Doherty, D. T., Favier, Z., Giacoppo, F., Huang, T. H., Kindler, B., Kondev, F. G., Lauritsen, T., Li, G. S., Lommel, B., Lu, H. Y., Mošať, P., Niu, Y. F., Raison, C., Reviol, W., Savard, G., Stolze, S., Wilson, G. L., Wu, H. Y., Wang, Z. H., Xu, F. R., Yu, X. H., Zeng, Q. B., Zhou, X. H.
• Format: Article
• Language: English
• Subjects: arrested anaerobic digestion; bioproducts; electromagnetic transitions; high-strength industrial wastewater; isomer decays; NUCLEAR PHYSICS AND RADIATION PHYSICS; nuclear structure & decays
• ISSN: 2469-9985; 2469-9993

The neutron-deficient 188Bi and 188Po isotopes have been studied by γ-ray spectroscopy using the recoil-decay tagging technique with the Argonne Gas-Filled Analyzer. A new 0.25(5)-μs isomeric state and a prompt cascade formed by 319-, 366-, and 462-keV γ rays have been established on top of the (10¯) α -decaying isomer in 188Bi. The first excited (2+) state in 188Po was identified, its excitation energy of 242(2) keV continues the nearly constant trend for the first 2+ states in 190, 192,194Po. Here, the state is most likely a member of a prolate rotational band built on the ground state, albeit mixing with other coexisting configurations cannot be excluded. The new results obtained in the present work provide new information to shape coexistence in bismuth and polonium isotopes near the neutron midshell at N = 104 . In this mass region, a reduction in the prompt γ-ray yield obtained with recoil decay tagging was observed for a few nuclides, and the possible reasons are presented.