ADOPTED LEVELS for 222Pa
Authors: Balraj Singh, M.S. Basunia, Jun Chen Et Al., | Citation: Nucl. Data Sheets 192, 315 (2023) | Cutoff date: 25-Sep-2023
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=-221×101 keV 10 | S(n)= 638×101 keV 11 | S(p)= 2160 keV 90 | Q(α)= 8790 keV 60 | ||
| Reference: 2021WA16 |
| References: | |||
| A | 226Np α decay (44 MS) | ||
| E(level) (keV) | XREF | T1/2(level) |
| 0 | A | 3.8 ms 6 % α = 100 |
| 107 30 | A | |
| 188 30 | A |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 3.8 ms 6 % α = 100 | Only the α decay has been observed for the decay of 222Pa. Theoretical partial T1/2=21.3 s for 222Pa ε decay (2019Mo01) gives %ε+%β+=0.02. Other: %ε+%β+≈4×10-4 from gross β- decay calculations (1973Ta30). |
Production and identification of 222Pa:
1970Bo13: 209Bi(16O,3n), 206Pb(19F,3n), excitation function; parent of 218Ac from 9210α.
1979Sc09: 184W(40Ar,pn),E=165-202 MeV, excitation function; parent of 218Ac from 9210α; and parent of 214Fr from 8430α.
2019Mi08: 222Pa produced in 181Ta(48Ca,X),E=212,217,226 MeV fusion-evaporation reactions at the UNILAC accelerator of GSI, followed by separation of evaporation residues (ERs) using the SHIP velocity filter and implanted into the COMPAct Spectroscopy Set-up (COMPASS). Measured Eα and half-life of 222Pa decay from time correlations between ERs and α particles.
2021Hu18: 222Pa produced in 186W(40Ar,p3n),E=198.7 MeV. The evaporation residues (ERs) were separated in-flight by the gas-filled recoil separator SHANS and implanted in three 16-strip position-sensitive silicon detectors (PSSDs) at the IMP-Lanzhou facility. 222Pa identified by ERs-α-α-α time and position correlations. Measured Eα, Iα, and T1/2 of g.s. of 222Pa.
Theoretical calculations for α decay:
2023Za01: calculated T1/2 for α decay using the generalized liquid-drop model with a 1977 nuclear proximity potential.
2022He18: calculated α-decay T1/2, α-preformation factor using density-dependent cluster model with RMF NN interactions, M3Y NN interactions and universal decay law (UDL) formula.
2021Sa52: calculated Q(2α), T1/2 for 2α-decay with and without the deformation effects using the modified generalized liquid drop model, and Coulomb and proximity potential model with different preformation factors for double α decay.
2018De17: calculated α-decay preformation factors using cluster-formation model (CFM) and T1/2(α) using a 1977 proximity potential (Prox. 1977).
2017Se19: calculated difference between proton and neutron skin thicknesses, Q(α) using Hartree-Fock-Bogoliubov (HFB) method, based on the Skyrme-like effective interactions.
Q-value: Q(ε)=4860 90, S(2n)=14360 90, S(2p)=6260 90 (2021Wa16)