ADOPTED LEVELS for 207Th
Author: Balraj Singh | Citation: ENSDF | Cutoff date: 31-AUG-2022
Full ENSDF file | Adopted Levels (PDF version)
| S(n)= 8990 keV CA | S(p)= 1160 keV CA | Q(α)= 8210 keV CA | |||
| Reference: 2019MO01 |
| E(level) (keV) | T1/2(level) |
| 0 | 10 ms +46-5 % α ≈ 100 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 10 ms +46-5 % α ≈ 100 | Only the α-decay mode has been observed. From theoretical half-lives of 1.24 s for β decay and 15 ms for α decay (2019Mo01), %ε+β+ is estimated as |<1.5%. E(level): Only the α-decay mode has been observed. From theoretical half-lives of 1.24 s for β decay and 15 ms for α decay (2019Mo01), %ε+β+ is estimated as |<1.5%. |
2022Ya15: 207Th nuclide produced and identified in 176Hf(36Ar,5n)207Th,E(36Ar)=197-199 MeV reaction at the sector focusing cyclotron of HIRFL, Lanzhou facility, followed by mass separation of fragments of interest using gas-filled recoil separator SHANS. Separated fragments were implanted in three position-sensitive silicon strip detectors (PSSDs) surrounded by eight non-position sensitive Si detectors. Measured evaporation residues (ERs), Eα, and one Er-α1-α2-α{-3-α{-4} correlated α-decay chain 207Th |) 203Ra |) 199Rn |) 195Po. Discussed odd-even staggering of Q(α) for nuclei with Z=84-92 and n=102-126.
Theoretical calculations: five primary references for decay characteristics, and one for atomic masses are in the NSR database (www.nndc.bnl.gov/nsr/) are listed in document records, which can be accessed via web retrievals of the ENSDF database (www.nndc.bnl.gov/ensdf/)
Event #1: Evaporation residue: 207Th, energy=6448 keV (2022Ya15)
Eα1=8167 keV, Δtα1=14.03 ms, assigned to 207Th α decay.
Eα2=7593 keV, Δtα2=0.322 ms, assigned to 203Ra α decay.
Eα3=5461+1570 keV, Δtα3=0.316 s, assigned to 199Rn α decay.
Eα4=6614 keV, Δtα4=8.044 s, assigned to 195Po α decay to 191Pb, which decays 99.9% by ε+β+ decay
Q-value: S(2n)=19690, S(2p)=1120 (2019Mo01, theory)