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Radionuclide Dosimetric Data Sheets
Polonium-203
Summary data
General
Classification
Isotope: Po-203
Atomic number (Z): 84
Mass number (A): 203
Neutron number (N): 119
Radioactive decay
Decay modes: α, β+, Electron capture
Half-life: 36.7 [m]
Decay constant: 3.1478e-04 [1/s]
Daughters: Bi-203 (99.9%), Pb-199 (0.11%)
Radioactive daughters: Bi-203, Pb-199
Dosimetric constants
Mean alpha energy: 0.006 [MeV]
Mean electron energy: 0.16716 [MeV]
Mean photon energy: 1.63477 [MeV]
Air kerma rate constant, Γ10: 7.146e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 7.421e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.774e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 9.613e-16
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
2.678e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 2.619e-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/Po-203 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/Po-203 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/Po-203 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/Po-203 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
2.66011e-05 |
1.121e-02 |
X-ray |
|
3.24839e-05 |
1.641e+01 |
X-ray |
|
2.46227e-03 |
6.551e-02 |
X-ray |
|
9.45110e-03 |
1.112e-02 |
X-ray |
|
1.07270e-02 |
1.945e-02 |
X-ray |
|
1.08390e-02 |
1.713e-01 |
X-ray |
|
1.29844e-02 |
3.325e-02 |
X-ray |
|
1.30700e-02 |
1.348e-01 |
X-ray |
|
1.53031e-02 |
2.782e-02 |
X-ray |
|
7.50642e-02 |
2.573e-01 |
X-ray |
|
7.74071e-02 |
4.302e-01 |
X-ray |
|
8.71393e-02 |
4.811e-02 |
X-ray |
|
8.76651e-02 |
9.324e-02 |
X-ray |
|
9.00323e-02 |
1.154e-02 |
X-ray |
|
9.01629e-02 |
2.273e-02 |
X-ray |
|
1.75200e-01 |
2.967e-02 |
Gamma |
|
1.89500e-01 |
3.846e-02 |
Gamma |
|
2.14800e-01 |
1.319e-02 |
Gamma |
|
2.14800e-01 |
1.428e-01 |
Gamma |
|
2.40400e-01 |
1.044e-02 |
Gamma |
|
2.61800e-01 |
1.154e-02 |
Gamma |
|
3.89900e-01 |
1.099e-02 |
Gamma |
|
4.19300e-01 |
2.417e-02 |
Gamma |
|
4.86100e-01 |
2.088e-02 |
Gamma |
|
4.86100e-01 |
2.088e-02 |
Gamma |
|
5.11000e-01 |
1.421e-01 |
Annihilation photon |
|
6.47700e-01 |
2.033e-02 |
Gamma |
|
8.22900e-01 |
2.362e-02 |
Gamma |
|
8.83500e-01 |
1.923e-02 |
Gamma |
|
8.93500e-01 |
1.868e-01 |
Gamma |
|
9.08600e-01 |
5.494e-01 |
Gamma |
|
1.09090e+00 |
1.923e-01 |
Gamma |
|
1.12390e+00 |
1.593e-02 |
Gamma |
|
1.24240e+00 |
4.615e-02 |
Gamma |
|
1.33790e+00 |
2.912e-02 |
Gamma |
|
1.35290e+00 |
1.373e-02 |
Gamma |
|
1.81750e+00 |
1.044e-02 |
Gamma |
|
9.62931e-01 |
1.697e-02 |
Positron |
|
1.04351e+00 |
3.493e-02 |
Positron |
|
4.07556e-05 |
3.820e+00 |
Auger electron |
|
8.95774e-05 |
5.219e+00 |
Auger electron |
|
1.73908e-04 |
2.787e+00 |
Auger electron |
|
4.30284e-04 |
6.345e-01 |
Auger electron |
|
1.07931e-03 |
1.849e-01 |
Auger electron |
|
1.96473e-03 |
1.488e+00 |
Auger electron |
|
2.24240e-03 |
1.957e-01 |
Auger electron |
|
2.65260e-03 |
1.005e-02 |
Auger electron |
|
8.30960e-03 |
4.339e-01 |
Auger electron |
|
1.07752e-02 |
1.953e-01 |
Auger electron |
|
1.32700e-02 |
2.099e-02 |
Auger electron |
|
6.03003e-02 |
2.132e-02 |
Auger electron |
|
7.26460e-02 |
1.172e-02 |
Auger electron |
|
8.43680e-02 |
5.282e-02 |
Conversion electron |
|
9.86680e-02 |
1.817e-02 |
Conversion electron |
|
1.23968e-01 |
2.923e-02 |
Conversion electron |
|
1.23968e-01 |
1.329e-02 |
Conversion electron |
|
1.73732e-01 |
9.524e-02 |
Conversion electron |
|
1.76075e-01 |
4.622e-02 |
Conversion electron |
|
1.86333e-01 |
4.153e-02 |
Conversion electron |
|
1.89500e-01 |
1.322e-02 |
Conversion electron |
|
1.99032e-01 |
1.176e-02 |
Conversion electron |
|
8.17768e-01 |
1.022e-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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