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Radionuclide Dosimetric Data Sheets
Barium-131m
Summary data
General
Classification
Isotope: Ba-131m
Atomic number (Z): 56
Mass number (A): 131
Neutron number (N): 75
Radioactive decay
Decay modes: Internal transition
Half-life: 14.6 [m]
Decay constant: 7.9126e-04 [1/s]
Daughters: Ba-131 (100.0%)
Radioactive daughters: Ba-131
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.11017 [MeV]
Mean photon energy: 0.07734 [MeV]
Air kerma rate constant, Γ10: 4.162e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 4.162e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.765e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 0.000e+00
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
1.765e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.239e-14
[Gy·kg/Bq·s]
Dose point kernels (plot)
Dose point kernel source: Graves, et al. Medical Physics. 2019 Nov.; 46(11):5284-5293.
Note: Bins are spaced every 0.1 mm until a radius of 10 cm, and every 1 mm until a radius of 2 m.
Download tabulated dose point kernel file here: www.mirdsoft.org/products/MIRDspecs/Ba-131m DPK.csv
Summary spectra (plot)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Download tabulated summary spectra file here: www.mirdsoft.org/products/MIRDspecs/Ba-131m Summary Spectrum.csv
Tabulated data
Summary spectra (table)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Note: Radiations with yield < 0.01 are excluded from the table, but are available in the linked *.csv data.
Download tabulated summary spectra file here: www.mirdsoft.org/products/MIRDspecs/Ba-131m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.86083e-05 |
1.791e+01 |
X-ray |
|
4.45292e-03 |
5.484e-02 |
X-ray |
|
4.82366e-03 |
4.153e-02 |
X-ray |
|
3.18187e-02 |
1.360e-01 |
X-ray |
|
3.22056e-02 |
2.505e-01 |
X-ray |
|
3.63167e-02 |
2.394e-02 |
X-ray |
|
3.63920e-02 |
4.639e-02 |
X-ray |
|
7.90500e-02 |
1.191e-02 |
Gamma |
|
1.08450e-01 |
5.517e-01 |
Gamma |
|
1.08631e-05 |
3.816e+00 |
Auger electron |
|
2.91100e-05 |
3.163e-02 |
Auger electron |
|
4.66202e-05 |
2.196e+00 |
Auger electron |
|
4.87601e-05 |
6.081e+00 |
Auger electron |
|
1.16315e-04 |
8.638e-01 |
Auger electron |
|
2.97136e-04 |
1.308e-01 |
Auger electron |
|
5.51772e-04 |
2.008e+00 |
Auger electron |
|
6.88877e-04 |
1.473e-01 |
Auger electron |
|
3.56624e-03 |
7.767e-01 |
Auger electron |
|
4.33082e-03 |
2.481e-01 |
Auger electron |
|
5.12367e-03 |
1.934e-02 |
Auger electron |
|
2.63448e-02 |
3.335e-02 |
Auger electron |
|
3.09583e-02 |
1.539e-02 |
Auger electron |
|
4.16010e-02 |
1.446e-01 |
Conversion electron |
|
7.10010e-02 |
3.804e-01 |
Conversion electron |
|
7.30892e-02 |
1.067e-02 |
Conversion electron |
|
7.34197e-02 |
3.078e-01 |
Conversion electron |
|
7.38066e-02 |
3.352e-01 |
Conversion electron |
|
7.79930e-02 |
1.518e-01 |
Conversion electron |
|
7.90500e-02 |
3.798e-02 |
Conversion electron |
|
1.02489e-01 |
4.686e-02 |
Conversion electron |
|
1.07393e-01 |
1.116e-02 |
Conversion electron |
Useful Links
Isotope decay characteristics are periodically updated as better measurements can be made - changes that may not be reflected on this page. Please see useful links:
National Nuclear Data Center (NNDC): https://www.nndc.bnl.gov/nudat3/mird/
International Atomic Energy Agency (IAEA) Livechart: https://www-nds.iaea.org/relnsd/vcharthtml/VChartHTML.html
Reference Links
ICRP Report 107: https://www.icrp.org/publication.asp?id=ICRP%20Publication%20107
Graves et al. Dose Point Kernels: https://doi.org/10.1002/mp.13789
MIRD Decay Schemes 2nd Edition: https://sites.snmmi.org/SNMMI-MAIN/iCore/Store/StoreLayouts/Item_Detail.aspx?iProductCode=0-932004-80-6
MIRDsoft MIRDspecs version 20250101 (www.mirdsoft.org)
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