ADOPTED LEVELS, GAMMAS for 189Po
Author: Balraj Singh | Citation: ENSDF | Cutoff date: 31-Aug-2021
Authors: T.D. Johnson, Balraj Singh | Citation: Nucl. Data Sheets 142, 1 (2017) | Cutoff date: 15-Apr-2017
Full ENSDF file | Adopted Levels (PDF version)
| S(n)= 8949 keV 30 | S(p)= 1516 keV 25 | Q(α)= 7694 keV 15 | |||
| Reference: 2021WA16 |
| References: | |||
| A | 193Rn α decay (1.15 MS) | ||
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) |
| 0 | A | (5/2-) | 3.5 ms 5 % α ≈ 100 | |||
| 194 | A | (3/2-,5/2-,7/2-) | 194 | 100 | (M1) |
| E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) (keV) | Multipolarity | Conversion Coefficient | Additional Data |
| 194 | (3/2-,5/2-,7/2-) | 194 | (M1) | 1.69 | α=1.69, α(K)=1.38, α(L)=0.24, α(M)=0.057, α(N)=0.0147, α(O)=0.00308, α(P)=0.000398 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | (5/2-) | 3.5 ms 5 % α ≈ 100 | %α: only α decay has been observed by 2005Va04 (and 1999An52) with Eα=7259 15, 7309 20 and 7532 20. In 1999An52, the possibility of an additional α decay from an additional isomeric level is mentioned, and based on a comparison with 191Po, it was suggested that the decay energy and half-life should be similar to decay from the ground state. 2005Va04, from the same experimental group, presented potential energy surface calculations suggesting there should be only one state from which α decay can occur. Although this is referred to as an isomeric state, it is likely that what is meant is the ground state. E(level): %α: only α decay has been observed by 2005Va04 (and 1999An52) with Eα=7259 15, 7309 20 and 7532 20. In 1999An52, the possibility of an additional α decay from an additional isomeric level is mentioned, and based on a comparison with 191Po, it was suggested that the decay energy and half-life should be similar to decay from the ground state. 2005Va04, from the same experimental group, presented potential energy surface calculations suggesting there should be only one state from which α decay can occur. Although this is referred to as an isomeric state, it is likely that what is meant is the ground state. |
| E(level) | E(gamma) | Comments |
| 194 | 194 | M(γ): from ce data in 193Rn α decay (2006An36) and prompt character of the transition. |
1999An52, 2001Hu21: 189Po produced by 142Nd(52Cr,5n), E=239-307 MeV, identified by the α-decay to the excited state of 185Pb. Target: 290 μg/cm2 142NdF3 enriched to 99.8%. Velocity filter SHIP
2005An17: Cross section for production of 189Po in heavy-ion reactions.
2005Va04: activity produced by 142Nd(52Cr,5n),E=5.27 MeV/nucleon; 142Nd(50Cr,3n),E=5.04 MeV/nucleon; 99.8% enriched 142Nd2F3 target; Detectors: velocity filter (SHIP), 16-strip position sensitive silicon detector for α-particles; 6 silicon detectors for conversion electrons; four-fold segmented Clover detector for γ. Measured E(α), I(α), E(γ), αγ-coin, α(ce) coin, αtot.
Theoretical calculations: consult NSR database at www.nndc.bnl.gov/nsr/ for 25 primary references for α decay, and three references (by the same author) on pre-scission neutron, proton, and α multiplicities in the fission process.
Q-value: Q(ε)=8640 30, S(2n)=20390 40, S(2p)=1013 23, Q(εp)=9100 24 (2021Wa16)