High-spin states in205Bi

Abstract

High-spin states in 2~populated in the 2~ 4n) reaction with bombarding energies around 50 MeV have been studied using 7-ray spectroscopic techniques. Spins and parities have been assigned on the basis of angular distribution and 7-ray linear polarization measurements. States with spins up to 39/2 + and excitation energies around 6 MeV have been identified. Calculations using the empirical shell model have been performed in order to assign configurations.

Emergence of an island of extreme nuclear isomerism at high excitation near 208Pb

“…The 8-ms isomer, therefore, most likely deexcites through one or more unobserved low-energy transitions with large conversion coefficients, accounting for their absence in the spectra. Similar considerations, as those outlined above for 204 Pb, have been employed in the case of 205 Bi, where the 2442-482-295 keV cascade feeds the previously established 4696-keV, 37/2 − level [22]. From the present work, the energy of this level is inferred to be about 1 keV lower i.e., 4695 keV.…”

“…Asterisks and hash marks designate unplaced and contaminant γ rays, respectively. The ones in black font were established earlier [22,23], while those in red have been identified from the present work. The present analysis, with the observed coincidence relationships, and the energy sums for the above three parallel decay paths, unambiguously establish the excitation energy of the isomer in 204 Pb as 8349 keV.…”

“…Details regarding the experiment and data analysis are presented elsewhere [21]. In previous reports on 205 Bi and 204 Pb, levels up to 6.7 MeV and 8.1 MeV, respectively, had been identified utilizing α particles as projectiles incident on 205 Tl and 204 Hg targets [22,23]. These experiments were focused on the decays of short-lived levels, and a number of transitions up to I ≈ 20 h were placed in the respective level schemes.…”

Emergence of an island of extreme nuclear isomerism at high excitation near $^{208}$Pb

“…Asterisks and hash marks designate unplacedand contaminant γ rays, respectively. The ones in black font were established earlier[22,23], while those in red have been identified from the present work.…”

“…Details regarding the experiment and data analysis are presented elsewhere [21]. In previous reports on 205 Bi and 204 Pb, levels up to 6.7 MeV and 8.1 MeV, respectively, had been identified utilizing α particles as projectiles incident on 205 Tl and 204 Hg targets [22,23]. These experiments were focused on the decays of short-lived levels, and a number of transitions up to I ≈ 20 were placed in the respective level schemes.…”