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Radionuclide Dosimetric Data Sheets
Barium-137m
Summary data
General
Classification
Isotope: Ba-137m
Atomic number (Z): 56
Mass number (A): 137
Neutron number (N): 81
Radioactive decay
Decay modes: Internal transition
Half-life: 2.552 [m]
Decay constant: 4.5268e-03 [1/s]
Daughters: Ba-137 (100.0%)
Radioactive daughters: None
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.06534 [MeV]
Mean photon energy: 0.59631 [MeV]
Air kerma rate constant, Γ10: 2.263e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.263e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.047e-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-:
1.047e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 9.554e-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-137m 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-137m 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-137m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.86004e-05 |
1.369e+00 |
X-ray |
|
3.18187e-02 |
2.160e-02 |
X-ray |
|
3.22056e-02 |
3.977e-02 |
X-ray |
|
6.61657e-01 |
8.974e-01 |
Gamma |
|
1.08630e-05 |
2.920e-01 |
Auger electron |
|
4.69626e-05 |
1.695e-01 |
Auger electron |
|
4.88221e-05 |
4.631e-01 |
Auger electron |
|
1.14579e-04 |
6.705e-02 |
Auger electron |
|
3.42997e-04 |
1.385e-02 |
Auger electron |
|
5.52330e-04 |
1.511e-01 |
Auger electron |
|
6.90733e-04 |
1.113e-02 |
Auger electron |
|
3.57126e-03 |
5.925e-02 |
Auger electron |
|
4.33797e-03 |
1.894e-02 |
Auger electron |
|
6.24208e-01 |
8.335e-02 |
Conversion electron |
|
6.55696e-01 |
1.208e-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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