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Radionuclide Dosimetric Data Sheets
Samarium-157
Summary data
General
Classification
Isotope: Sm-157
Atomic number (Z): 62
Mass number (A): 157
Neutron number (N): 95
Radioactive decay
Decay modes: β-
Half-life: 8.03 [m]
Decay constant: 1.4387e-03 [1/s]
Daughters: Eu-157 (100.0%)
Radioactive daughters: Eu-157
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.875 [MeV]
Mean photon energy: 0.41416 [MeV]
Air kerma rate constant, Γ10: 1.485e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.485e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.402e-13 [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-:
1.402e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 6.636e-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-157 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-157 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-157 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-157 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.42257e-05 |
2.827e+00 |
X-ray |
|
5.83100e-03 |
1.824e-02 |
X-ray |
|
6.45760e-03 |
1.176e-02 |
X-ray |
|
4.09430e-02 |
6.796e-02 |
X-ray |
|
4.15992e-02 |
1.226e-01 |
X-ray |
|
4.69640e-02 |
1.237e-02 |
X-ray |
|
4.70984e-02 |
2.393e-02 |
X-ray |
|
5.91680e-02 |
1.120e-02 |
Gamma |
|
7.67010e-02 |
1.876e-02 |
Gamma |
|
1.21147e-01 |
4.760e-02 |
Gamma |
|
1.90273e-01 |
1.126e-02 |
Gamma |
|
1.93400e-01 |
1.064e-02 |
Gamma |
|
1.96461e-01 |
1.663e-01 |
Gamma |
|
1.97870e-01 |
5.600e-01 |
Gamma |
|
2.63207e-01 |
1.344e-02 |
Gamma |
|
3.17460e-01 |
1.299e-02 |
Gamma |
|
3.94351e-01 |
1.193e-01 |
Gamma |
|
9.88380e-01 |
1.456e-02 |
Gamma |
|
1.46316e+00 |
2.856e-02 |
Gamma |
|
2.53688e-01 |
1.158e-02 |
Beta |
|
2.92258e-01 |
1.158e-02 |
Beta |
|
4.48743e-01 |
3.668e-02 |
Beta |
|
4.82309e-01 |
1.158e-02 |
Beta |
|
4.91582e-01 |
1.158e-02 |
Beta |
|
6.24683e-01 |
1.544e-02 |
Beta |
|
6.51473e-01 |
1.834e-02 |
Beta |
|
7.71025e-01 |
1.641e-02 |
Beta |
|
7.91367e-01 |
2.510e-02 |
Beta |
|
8.88090e-01 |
1.641e-01 |
Beta |
|
9.14617e-01 |
1.255e-01 |
Beta |
|
1.00308e+00 |
4.151e-01 |
Beta |
|
1.04243e+00 |
2.413e-02 |
Beta |
|
1.09267e+00 |
2.896e-02 |
Beta |
|
1.58398e-05 |
2.001e-01 |
Auger electron |
|
1.04985e-04 |
1.370e-01 |
Auger electron |
|
1.13031e-04 |
1.219e+00 |
Auger electron |
|
1.79251e-04 |
1.928e-01 |
Auger electron |
|
5.40353e-04 |
3.714e-02 |
Auger electron |
|
8.53794e-04 |
4.182e-01 |
Auger electron |
|
1.02581e-03 |
2.575e-02 |
Auger electron |
|
4.61606e-03 |
1.544e-01 |
Auger electron |
|
5.71695e-03 |
5.318e-02 |
Auger electron |
|
1.06000e-02 |
1.229e-01 |
Conversion electron |
|
2.81330e-02 |
8.401e-02 |
Conversion electron |
|
3.36229e-02 |
1.114e-02 |
Auger electron |
|
5.11499e-02 |
1.613e-02 |
Conversion electron |
|
6.86829e-02 |
1.100e-02 |
Conversion electron |
|
1.49302e-01 |
2.155e-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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