ADOPTED LEVELS for 206Ac
Author: F.G. Kondev | Citation: Nucl. Data Sheets 201, 346 (2025) | Cutoff date: 21-Jan-2025
Full ENSDF file | Adopted Levels (PDF version)
| S(n)= 8690 keV 90 | S(p)= -390 keV 70 | Q(α)= 7960 keV 60 | |||
| Reference: 2021WA16 |
| E(level) (keV) | Jπ(level) | T1/2(level) |
| 0.0 | 3+ | 22 ms +9-5 % α ≈ 100 |
| 200 70 | (10-) | 33 ms +22-9 % α ≈ 100 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0.0 | 3+ | 22 ms +9-5 % α ≈ 100 | Configuration=π(h9/2+1)#ν(f5/2-1)3+. E(level): Configuration=π(h9/2+1)#ν(f5/2-1)3+. |
| 200 | (10-) | 33 ms +22-9 % α ≈ 100 | Configuration=π(h9/2+1)#ν(i13/2-1)10-. E(level): Configuration=π(h9/2+1)#ν(i13/2-1)10-. |
2014Zh03: 206Ac produced by bombarding a 400 μg/cm2 thick 169Tm target covered with a 10 μg/cm2 carbon layer with 196 MeV 40Ca beam at HIRFL in Lanzhou. Evaporation residues were separated in flight using the SHANS recoil separator, and implanted into position sensitive silicon detectors. The α particles were detected by eight non-position sensitive Si detectors with FWHM=70 keV for 6-7 MeV α’s. Three α-decay chains were observed with Eα(1)[206Ac]=7817 keV 30, Eα(2)[202Fr]=7245 keV 30 and Eα(3)[198At]=6775 keV 30 with half-lives of 41 ms +56-15, 0.29 s +40-11 and 3.1 s +56-12, respectively.
1998Es02: Activity produced by bombarding a 320 μg/cm2 thick 175Lu target with 199 MeV 36Ar ions. The reaction products were separated by the gas-filled separator (RITU) and implanted into a position sensitive PIPS detector (800 mm wide and 35 mm high). Separate amplified branches for energy ranges 0.5-15 MeV (α-decay) and 2-200 MeV (reaction residues) were used. Two α-decaying states were identified, one using 9 quadruple (recoil-α1-α2-α{-3) and 2 triple (recoil-α1-α3) (Eα2 missing) events: 7790 keV 30 (α1), 7236 keV 7 (α2), 6752 keV 6 (α3) associated with the 3+ ground state and the other using 5 quadruple and 1 triple (Eα2 missing) events: 7750 keV 20 (α1), 7248 keV 13 (α2) and 6858 keV 7 (α3) associated with the 10- isomer. The assignment to a specific state is based on the time and position correlations with known α-decays of 202Fr, 198At and 194Bi
1998LuZV: Activity produced by bombarding a 307 μg/cm2 hafnium target (64.6% 176Hf,21.7% 177Hf, 6.8% 178Hf, 2.2% 179Hf and 4.7% 180Hf) with 186-MeV (effective energy at half-target thickness) 35Cl ions (beam intensity was about 600 enA). The reaction products were separated by a recoil mass separator at JAERI and implanted on a position-sensitive silicon detector. Two α decaying states were identified, one using 4 quadruple (recoil-α1-α2-α{-3) and one triple (recoil-α1-α2) events: 7894 keV 50 (α1), 7183 keV 50 (α2) and 6742 keV 50 (α3) and the other using 3 triple events (recoil-α1-α3) (Eα2 missing): 7772 keV 50 (α1) and 6760 keV (α3).
Q-value: S(2p)=1700 70, Q(ε)=9920 70, Q(εp)=7510 70 (2021Wa16)