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Radionuclide Dosimetric Data Sheets
Strontium-81
Summary data
General
Classification
Isotope: Sr-81
Atomic number (Z): 38
Mass number (A): 81
Neutron number (N): 43
Radioactive decay
Decay modes: β+, Electron capture
Half-life: 22.3 [m]
Decay constant: 5.1805e-04 [1/s]
Daughters: Rb-81 (99.9%), Rb-81m (0.144%)
Radioactive daughters: Rb-81, Rb-81m
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.97425 [MeV]
Mean photon energy: 1.3866 [MeV]
Air kerma rate constant, Γ10: 2.112e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 5.500e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.561e-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-:
1.561e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 2.222e-13
[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/Sr-81 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/Sr-81 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/Sr-81 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/Sr-81 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.52781e-05 |
1.815e+00 |
X-ray |
|
1.32919e-02 |
3.449e-02 |
X-ray |
|
1.33539e-02 |
6.635e-02 |
X-ray |
|
1.42150e-01 |
3.027e-02 |
Gamma |
|
1.47760e-01 |
3.010e-01 |
Gamma |
|
1.53540e-01 |
3.377e-01 |
Gamma |
|
1.88270e-01 |
1.540e-01 |
Gamma |
|
2.55160e-01 |
1.558e-02 |
Gamma |
|
3.01300e-01 |
1.452e-02 |
Gamma |
|
3.86550e-01 |
1.645e-02 |
Gamma |
|
4.43340e-01 |
1.750e-01 |
Gamma |
|
4.65800e-01 |
1.208e-02 |
Gamma |
|
4.86690e-01 |
1.172e-02 |
Gamma |
|
5.11000e-01 |
1.751e+00 |
Annihilation photon |
|
5.23710e-01 |
1.330e-02 |
Gamma |
|
5.74670e-01 |
6.738e-02 |
Gamma |
|
6.07880e-01 |
1.365e-02 |
Gamma |
|
7.02140e-01 |
1.013e-02 |
Gamma |
|
7.11900e-01 |
1.383e-02 |
Gamma |
|
7.20810e-01 |
3.535e-02 |
Gamma |
|
9.09030e-01 |
2.712e-02 |
Gamma |
|
9.38450e-01 |
2.958e-02 |
Gamma |
|
5.94240e-01 |
1.971e-02 |
Positron |
|
6.71584e-01 |
3.350e-02 |
Positron |
|
8.87396e-01 |
7.784e-02 |
Positron |
|
9.78473e-01 |
2.266e-02 |
Positron |
|
1.04217e+00 |
7.390e-02 |
Positron |
|
1.10338e+00 |
1.577e-01 |
Positron |
|
1.16985e+00 |
2.759e-01 |
Positron |
|
1.22287e+00 |
6.503e-02 |
Positron |
|
1.31145e+00 |
1.182e-01 |
Positron |
|
1.26043e-05 |
5.320e-01 |
Auger electron |
|
6.49977e-05 |
5.334e-01 |
Auger electron |
|
7.35485e-05 |
2.153e-01 |
Auger electron |
|
1.06576e-04 |
4.285e-02 |
Auger electron |
|
1.48966e-03 |
2.015e-01 |
Auger electron |
|
1.61137e-03 |
1.632e-02 |
Auger electron |
|
1.14024e-02 |
4.396e-02 |
Auger electron |
|
1.30522e-02 |
1.443e-02 |
Auger electron |
|
1.32601e-01 |
3.716e-02 |
Conversion electron |
|
1.38381e-01 |
1.825e-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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