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Radionuclide Dosimetric Data Sheets
Selenium-75
Summary data
General
Classification
Isotope: Se-75
Atomic number (Z): 34
Mass number (A): 75
Neutron number (N): 41
Radioactive decay
Decay modes: Electron capture
Half-life: 119.8 [d]
Decay constant: 6.6978e-08 [1/s]
Daughters: As-75 (100.0%)
Radioactive daughters: None
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.01444 [MeV]
Mean photon energy: 0.38898 [MeV]
Air kerma rate constant, Γ10: 4.246e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 4.246e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.314e-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-:
2.314e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 6.232e-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/Se-75 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/Se-75 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/Se-75 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.42086e-05 |
8.882e+00 |
X-ray |
|
1.04633e-02 |
1.634e-01 |
X-ray |
|
1.05007e-02 |
3.165e-01 |
X-ray |
|
1.16800e-02 |
2.160e-02 |
X-ray |
|
1.16852e-02 |
4.219e-02 |
X-ray |
|
6.60518e-02 |
1.112e-02 |
Gamma |
|
9.67340e-02 |
3.420e-02 |
Gamma |
|
1.21116e-01 |
1.720e-01 |
Gamma |
|
1.36000e-01 |
5.825e-01 |
Gamma |
|
1.98606e-01 |
1.478e-02 |
Gamma |
|
2.64658e-01 |
5.890e-01 |
Gamma |
|
2.79542e-01 |
2.499e-01 |
Gamma |
|
3.03924e-01 |
1.316e-02 |
Gamma |
|
4.00657e-01 |
1.147e-01 |
Gamma |
|
2.23274e-05 |
4.187e+00 |
Auger electron |
|
5.24624e-05 |
1.544e+00 |
Auger electron |
|
9.87300e-05 |
2.589e-01 |
Auger electron |
|
1.15652e-03 |
1.291e+00 |
Auger electron |
|
1.22349e-03 |
4.580e-02 |
Auger electron |
|
9.06608e-03 |
3.321e-01 |
Auger electron |
|
1.02994e-02 |
9.430e-02 |
Auger electron |
|
1.25525e-02 |
4.481e-02 |
Conversion electron |
|
8.49050e-02 |
2.648e-02 |
Conversion electron |
|
1.24171e-01 |
1.544e-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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