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Radionuclide Dosimetric Data Sheets
Terbium-156m
Summary data
General
Classification
Isotope: Tb-156m
Atomic number (Z): 65
Mass number (A): 156
Neutron number (N): 91
Radioactive decay
Decay modes: Internal transition
Half-life: 24.4 [h]
Decay constant: 7.8910e-06 [1/s]
Daughters: Tb-156 (100.0%)
Radioactive daughters: Tb-156
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.01705 [MeV]
Mean photon energy: 0.03695 [MeV]
Air kerma rate constant, Γ10: 1.939e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.939e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.732e-15 [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-:
2.732e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 5.920e-15
[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/Tb-156m 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/Tb-156m 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/Tb-156m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.38437e-05 |
7.487e+00 |
X-ray |
|
1.17434e-03 |
1.211e-02 |
X-ray |
|
6.26070e-03 |
1.274e-02 |
X-ray |
|
4.96300e-02 |
7.370e-01 |
Gamma |
|
1.73725e-05 |
4.465e-01 |
Auger electron |
|
1.21413e-04 |
3.483e+00 |
Auger electron |
|
1.35617e-04 |
2.091e-01 |
Auger electron |
|
2.06553e-04 |
6.667e-01 |
Auger electron |
|
6.46900e-04 |
7.014e-02 |
Auger electron |
|
9.71869e-04 |
1.071e+00 |
Auger electron |
|
1.15997e-03 |
6.398e-02 |
Auger electron |
|
2.80320e-03 |
7.885e-01 |
Conversion electron |
|
4.40000e-03 |
2.139e-01 |
Conversion electron |
|
5.07606e-03 |
1.206e-01 |
Auger electron |
|
6.29785e-03 |
4.244e-02 |
Auger electron |
|
4.09569e-02 |
1.076e-01 |
Conversion electron |
|
4.13691e-02 |
4.153e-02 |
Conversion electron |
|
4.21247e-02 |
5.597e-02 |
Conversion electron |
|
4.80332e-02 |
4.496e-02 |
Conversion electron |
|
4.96300e-02 |
1.199e-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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