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Radionuclide Dosimetric Data Sheets
Samarium-156
Summary data
General
Classification
Isotope: Sm-156
Atomic number (Z): 62
Mass number (A): 156
Neutron number (N): 94
Radioactive decay
Decay modes: β-
Half-life: 9.4 [h]
Decay constant: 2.0483e-05 [1/s]
Daughters: Eu-156 (100.0%)
Radioactive daughters: Eu-156
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.20925 [MeV]
Mean photon energy: 0.11498 [MeV]
Air kerma rate constant, Γ10: 4.355e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 4.355e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 3.353e-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-:
3.353e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.842e-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/Sm-156 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/Sm-156 Summary Spectrum.csv
Beta spectra (plot)
Spectra source: ICRP Publication 107: Nuclear Decay Data for Dosimetric Calculations. Ann. ICRP 2008, 38 (3).
Download tabulated beta spectra file here: www.mirdsoft.org/products/MIRDspecs/Sm-156 Beta 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/Sm-156 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.43105e-05 |
9.524e+00 |
X-ray |
|
1.03883e-03 |
1.127e-02 |
X-ray |
|
5.83099e-03 |
3.440e-02 |
X-ray |
|
6.41408e-03 |
1.324e-02 |
X-ray |
|
6.45761e-03 |
2.892e-02 |
X-ray |
|
6.54850e-03 |
1.910e-02 |
X-ray |
|
2.26000e-02 |
2.626e-02 |
Gamma |
|
3.81000e-02 |
2.940e-02 |
Gamma |
|
4.09430e-02 |
3.282e-02 |
X-ray |
|
4.15992e-02 |
5.920e-02 |
X-ray |
|
4.70984e-02 |
1.156e-02 |
X-ray |
|
6.50000e-02 |
2.254e-02 |
Gamma |
|
8.76000e-02 |
2.352e-01 |
Gamma |
|
1.03000e-01 |
1.764e-02 |
Gamma |
|
1.65800e-01 |
1.274e-01 |
Gamma |
|
2.04000e-01 |
2.058e-01 |
Gamma |
|
2.44000e-01 |
2.058e-02 |
Gamma |
|
2.68500e-01 |
2.352e-02 |
Gamma |
|
2.91000e-01 |
2.744e-02 |
Gamma |
|
1.27662e-01 |
4.567e-01 |
Beta |
|
2.23315e-01 |
5.361e-01 |
Beta |
|
1.58398e-05 |
7.032e-01 |
Auger electron |
|
1.10304e-04 |
4.692e-01 |
Auger electron |
|
1.12584e-04 |
4.127e+00 |
Auger electron |
|
1.80665e-04 |
7.499e-01 |
Auger electron |
|
5.81736e-04 |
3.558e-01 |
Auger electron |
|
8.61304e-04 |
1.234e+00 |
Auger electron |
|
1.04476e-03 |
7.784e-02 |
Auger electron |
|
4.80956e-03 |
4.520e-01 |
Auger electron |
|
5.93175e-03 |
1.575e-01 |
Auger electron |
|
7.09848e-03 |
1.381e-02 |
Auger electron |
|
1.45819e-02 |
4.320e-01 |
Conversion electron |
|
1.49752e-02 |
3.896e-02 |
Conversion electron |
|
1.64320e-02 |
1.681e-02 |
Conversion electron |
|
1.72819e-02 |
2.949e-02 |
Conversion electron |
|
2.11304e-02 |
1.035e-01 |
Conversion electron |
|
2.26000e-02 |
2.889e-02 |
Conversion electron |
|
3.00819e-02 |
1.030e-01 |
Conversion electron |
|
3.66304e-02 |
2.460e-02 |
Conversion electron |
|
3.90320e-02 |
8.013e-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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