ADOPTED LEVELS, GAMMAS for 149Ba
Authors: Balraj Singh and Jun Chen | Citation: Nucl. Data Sheets 185, 2 (2022) | Cutoff date: 23-Aug-2022
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=7.39×103 keV 20 | S(n)= 3357.0 keV 29 | S(p)= 13209 keV 13 | Q(α)= -3762 keV 11 | ||
| Reference: 2021WA16 |
| References: | |||
| A | 149Cs β- decay (107 MS) | B | 150Cs β-n decay (81 MS) |
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) | Final Levels | |
| 0.0 | AB | (5/2-,3/2-) | 352 ms 6 % β- = 100 % β-n = 2.2 17 | |||||
| 46.87 10 | A | (1/2:7/2)[-] | 0.6 ns 2 | 46.80 18 | 100 | [M1] | 0.0 | (5/2-,3/2-) |
| 68.19 9 | A | (1/2:7/2)[-] | 0.6 ns 5 | 68.10 13 | 100 | [M1] | 0.0 | (5/2-,3/2-) |
| 124.93 13 | A | 78.20 13 124.70 23 | 100 26 77 11 | 46.87 0.0 | (1/2:7/2)[-] (5/2-,3/2-) | |||
| 164.79 20 | A | (1/2:7/2)(+) | 96.60 18 | 100 | (E1) | 68.19 | (1/2:7/2)[-] | |
| 236.45 10 | A | 168.10 11 189.50 30 236.70 13 | 100 13 41 6 24 7 | 68.19 46.87 0.0 | (1/2:7/2)[-] (1/2:7/2)[-] (5/2-,3/2-) | |||
| 279.27 12 | A | 211.20 11 279.00 17 | 100 14 57 8 | 68.19 0.0 | (1/2:7/2)[-] (5/2-,3/2-) | |||
| 282.73 10 | AB | 282.90 13 | 100 | 0.0 | (5/2-,3/2-) | |||
| 316.56 9 | AB | 248.20 46 316.6 1 | 5.3 10 100 5 | 68.19 0.0 | (1/2:7/2)[-] (5/2-,3/2-) | |||
| 362.29 23 | A | 294.10 21 | 100 | 68.19 | (1/2:7/2)[-] | |||
| 389.64 13 | A | 342.90 19 389.70 21 | 100 15 41 29 | 46.87 0.0 | (1/2:7/2)[-] (5/2-,3/2-) | |||
| 481.83 25 | A | 356.90 21 | 100 | 124.93 | ||||
| 488.05 10 | A | 171.60 13 205.90 12 363.30 21 441.00 12 487.70 11 | 100 6 50 4 26 8 56 5 100 7 | 316.56 282.73 124.93 46.87 0.0 | (1/2:7/2)[-] (5/2-,3/2-) | |||
| 665.33 9 | A | 275.90 21 348.60 24 382.60 11 665.30 11 | 21 3 26 4 92 5 100 6 | 389.64 316.56 282.73 0.0 | (5/2-,3/2-) | |||
| 682.56 17 | A | 366.00 14 | 100 | 316.56 | ||||
| E(level) (keV) | XREF | Jπ(level) | T1/2(level) | E(γ) (keV) | I(γ) | M(γ) | Final Levels | |
| 727.05 16 | A | 490.60 13 | 100 | 236.45 | ||||
| 911.3 21 | A | 594.7 21 | 100 | 316.56 | ||||
| 917.7 4 | A | 601.10 32 | 100 | 316.56 | ||||
E(level): From a least-squares fit to Eγ values. Uncertainties of 205.9γ and 487.7γ were doubled to 0.24 and 0.22 keV, respectively to obtain a better fit for the 488-keV level.
T1/2(level): From βγ(t) in 149Cs β- decay (2017Li06), except where noted.
| E(level) (keV) | Jπ(level) | T1/2(level) | E(γ) (keV) | Multipolarity | Conversion Coefficient | Additional Data |
| 46.87 | (1/2:7/2)[-] | 0.6 ns 2 | 46.80 18 | [M1] | 8.87 | B(M1)(W.u.)=0.036 +34-14, α=8.87 16 |
| 68.19 | (1/2:7/2)[-] | 0.6 ns 5 | 68.10 13 | [M1] | 2.98 | B(M1)(W.u.)=0.029 +145-13, α=2.98 4 |
| 164.79 | (1/2:7/2)(+) | 96.60 18 | (E1) | 0.250 | α=0.250 4 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0.0 | (5/2-,3/2-) | 352 ms 6 % β- = 100 % β-n = 2.2 17 | Theoretical T1/2=177 ms, %β-n=1.26 and 1.38 for different fission barriers (2021Mi17). |
| E(level) | E(gamma) | Comments |
| 46.87 | 46.80 | M(γ): From analogy with 147Ba structure. Pure E2 is not allowed by RUL |
| 68.19 | 68.10 | M(γ): From analogy with 147Ba structure. Pure E2 is not allowed by RUL |
| 164.79 | 96.60 | M(γ): from lack of observation of Ba X-rays in coincidence with the 68.1γ |
Isotopic assignment: 1986ReZU, 1987MaZY, 1993Ru01, 2017Wu04
2016Kn03: measurement of mass excess of 149Ba g.s. using FRS-ESR-facility at GSI
2017Wu04: The 149Ba nuclide was produced at the RIBF-RIKEN facility using the 9Be(238U,F) reaction at E=345 MeV/nucleon. Two experiments, optimized for the transmission of 158Nd and 170Dy ions, were carried out with average beam intensities of 7 pnA and 12 pnA, respectively. The identification of the nuclide of interest was made in the BigRIPS separator by determining the atomic number and the mass-to-charge ratio of the ion using the tof-Bρ-ΔE method. The reaction products were transported through the ZeroDegree Spectrometer and implanted into the beta-counting system WAS3ABi that was surrounded by the EURICA array comprising of 84 HPGe detectors. The typical implantation rate was ~100 ions/s. Measured: implanted ion-β--t, implanted ion-β--γ-t and implanted ions-γ-t correlations. Deduced: T1/2.
2020Wu04: 149Ba nuclide produced at the RIBF-RIKEN facility in 9Be(238U,F) reaction at E=345 MeV/nucleon and an intensity of 5pnA. Identification of fission fragments of interest was made based on time-of-flight (tof), magnetic rigidity (Bρ), and energy loss (ΔE) using the BigRIPS spectrometer, determining atomic Z and mass-to-charge ratio α/Q, where Q=charge state of the ions. The separated nuclei were implanted at a rate of 100 ions/s in the β counting system of the Wide range Active Silicon-Strip Stopper Array for Beta and ion detection (WAS3ABi), which included a stack of five Double Sided Silicon Strip Detectors (DSSSDs). The WAS3ABi setup was surrounded by Euroball RIken Cluster Array (EURICA) array of 84 HPGe detectors for γ detection. Half-life of the separated and implanted ions was determined by fitting the time distribution of β(implants)- and/or βγ(implants)-correlated decay curves to the sum of activities of parent nuclei, daughter nuclei, grand-daughter nuclei, β-delayed neutron daughter and grand-daughter nuclei, and a constant background. Comparison of measured half-lives with FRDM+QRPA (2003), FRDM+QRPA (2019), KTUY+GT2, RHB+pn-RQRPA, and DF+CQRPA theoretical calculations.
Theoretical studies: consult the NSR database at www.nndc.bnl.gov/nsr/ for five references for nuclear structure theory, listed under ’document records’ which can be accessed through web retrieval of the ENSDF database at www.nndc.bnl.gov/ensdf/
Q-value: S(2n)=8709 20, S(2p)=25010 200 (syst), Q(β-n)=1807 20 (2021Wa16)