ADOPTED LEVELS:TENTATIVE for 205Ac
Author: F.G. Kondev | Citation: Nucl. Data Sheets 166, 1 (2020) | Cutoff date: 20-Apr-2020
Full ENSDF file | Adopted Levels (PDF version)
| S(p)= -760 keV 50 | Q(α)= 8090 keV 50 | ||||
| Reference: 2017WA10 |
| E(level) (keV) | Jπ(level) | T1/2(level) |
| 0.0 | (9/2-) | 20 ms +97-9 % α ≈ 100 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0.0 | (9/2-) | 20 ms +97-9 % α ≈ 100 | Only one correlated decay-chain event was observed with Eα(1)=7935 30 keV, Δt(1)=29.1 ms; Eα(2)=7406 keV, Δt(2)=85 ms and Eα(3)=6997 keV, Δt(3)=2.08 s. Definite assignment is ambiguous, since: Eα(2) is consistent with Eα’s of both, the 201Fr g.s. (Jπ=9/2-) [Eα=7369 keV 3 (2005Uu02,2007Ko06)] and the 201mFr isomer (Jπ=1/2+) [Eα=7454 keV 8 (2005Uu02,2007Ko06)], but Δt(2) is consistent only with T1/2 for the 201Fr g.s. (Jπ=9/2-) [T1/2=62 ms 5 (2007Ko06)] (201mFr isomer (Jπ=1/2+) [T1/2=19 ms +19-6 (2007Ko06)]); Eα(3) is only consistent with Eα of 197At g.s. (Jπ=9/2-) [Eα=6959 keV 6 (2005Uu02)] (197mAt isomer (Jπ=1/2+) [Eα=6706 keV 6 (2005Uu02)]), but Δt(3) is close to T1/2 of the 197mAt isomer (Jπ=1/2+) [T1/2=1.1 s +11-4 (2005Uu02)] (197At g.s. (Jπ=9/2-) [T1/2=340 ms 20 (2005Uu02)]). E(level): Only one correlated decay-chain event was observed with Eα(1)=7935 30 keV, Δt(1)=29.1 ms; Eα(2)=7406 keV, Δt(2)=85 ms and Eα(3)=6997 keV, Δt(3)=2.08 s. Definite assignment is ambiguous, since: Eα(2) is consistent with Eα’s of both, the 201Fr g.s. (Jπ=9/2-) [Eα=7369 keV 3 (2005Uu02,2007Ko06)] and the 201mFr isomer (Jπ=1/2+) [Eα=7454 keV 8 (2005Uu02,2007Ko06)], but Δt(2) is consistent only with T1/2 for the 201Fr g.s. (Jπ=9/2-) [T1/2=62 ms 5 (2007Ko06)] (201mFr isomer (Jπ=1/2+) [T1/2=19 ms +19-6 (2007Ko06)]); Eα(3) is only consistent with Eα of 197At g.s. (Jπ=9/2-) [Eα=6959 keV 6 (2005Uu02)] (197mAt isomer (Jπ=1/2+) [Eα=6706 keV 6 (2005Uu02)]), but Δt(3) is close to T1/2 of the 197mAt isomer (Jπ=1/2+) [T1/2=1.1 s +11-4 (2005Uu02)] (197At g.s. (Jπ=9/2-) [T1/2=340 ms 20 (2005Uu02)]). |
2014Zh03: 205Ac produced and identified in 169Tm(40Ca,4n) reaction, E(40Ca)=196 MeV at HIRFL, Lanzhou. The target was 400 μg/cm2 thick and covered with a thin 10 μg/cm2 carbon layer. Evaporation residues were separated in flight using the gas-filled recoil separator SHANS and implanted into a position sensitive silicon detector (150×50 mm2 with 48 vertical strips, 3 mm width, FWHM=70 keV for Eα=6-7 MeV). Eight non-position sensitive Si detectors (50×50 mm2) were located perpendicular to the face of the implantation detector to detect escape Eα’s. The nuclei of interest were identified by energy, time, and position correlations of implanted evaporation residues and their subsequent α decays with the observation of α1-α2-α{-3 correlated events. Calibration of the Si detectors was completed using internal decays of 200Po (5863 keV 2), 201At (6344 keV 2), 204Rn (6418.9 keV 25), 206Fr (6790 keV 4), 205Fr (6915 keV 4), and 204Fr (7031 keV 5)