ADOPTED LEVELS for 191At
Author: M.S. Basunia | Citation: Nucl. Data Sheets 195, 368 (2024) | Cutoff date: 1-Dec-2023
Full ENSDF file | Adopted Levels (PDF version)
| S(p)= -1138 keV 21 | Q(α)= 7822 keV 14 | ||||
| Reference: 2021WA16 |
| E(level) (keV) | Jπ(level) | T1/2(level) |
| 0.0 | (1/2+) | 1.7 ms +11-5 % α ≈ 100 |
| 58 20 | (7/2-) | 2.1 ms +4-3 % α ≈ 100 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0.0 | (1/2+) | 1.7 ms +11-5 % α ≈ 100 | Proposed as the 191At g.s. in 2003Ke08, 2005Ke10. This state decays by Eα=7552 keV 11, ≈100% α branching, HF=0.4 3, to the ≈112 keV (1/2+) level in 187Bi (2003Ke08). This is similar to the case of the neighboring 193At ground state. α reduced α decay width of δ2=150 keV 100 is quoted in 2003Ke08 (see also 2005Uu03) for this transition. E(level): Proposed as the 191At g.s. in 2003Ke08, 2005Ke10. This state decays by Eα=7552 keV 11, ≈100% α branching, HF=0.4 3, to the ≈112 keV (1/2+) level in 187Bi (2003Ke08). This is similar to the case of the neighboring 193At ground state. α reduced α decay width of δ2=150 keV 100 is quoted in 2003Ke08 (see also 2005Uu03) for this transition. |
| 58 | (7/2-) | 2.1 ms +4-3 % α ≈ 100 | This level decays by Eα=7653 keV 13, Iα=98% 2, HF=1.1 3, to the ≈63 keV (7/2-) level in 187Bi, and Eα=7715 keV 15, Iα=2% 2, HF=50 50 to the (9/2-) 187Bi ground state (2003Ke08). α reduced α decay width of δ2=59 13 and 1.3 13 keV is reported in 2003Ke08 for the 7653 and 7715 keV α transitions, respectively (also in 2005Uu03 for the former transition). E(level): This level decays by Eα=7653 keV 13, Iα=98% 2, HF=1.1 3, to the ≈63 keV (7/2-) level in 187Bi, and Eα=7715 keV 15, Iα=2% 2, HF=50 50 to the (9/2-) 187Bi ground state (2003Ke08). α reduced α decay width of δ2=59 13 and 1.3 13 keV is reported in 2003Ke08 for the 7653 and 7715 keV α transitions, respectively (also in 2005Uu03 for the former transition). |
Identification: Observation of recoil-α-α correlations with 187Bi in the reaction 141Pr(54Fe,4n)191At (2002LeZZ).
Observation of α decay in fusion-evaporation measurements using the 141Pr(54Fe,4n) reaction at E=248-266 MeV, at mid-target. Gas-filled recoil fragment separator RITU. Recoil and α detection by position-sensitive Si strip detector (2003Ke08,2005Ke10).
Other references: 2005Ke10, 2005Uu03.
Levels: Levels proposed on the basis of recoil-tagged α-α coincidences, measured E(α), and considering α-decay links to levels in the daughter nuclide 187Bi. No γ-rays from 187Bi were observed due to poor statistics (2003Ke08).