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Radionuclide Dosimetric Data Sheets
Protactinium-228
Summary data
General
Classification
Isotope: Pa-228
Atomic number (Z): 91
Mass number (A): 228
Neutron number (N): 137
Radioactive decay
Decay modes: α, β+, Electron capture
Half-life: 22.0 [h]
Decay constant: 8.7519e-06 [1/s]
Daughters: Th-228 (98.0%), Ac-224 (2.0%)
Radioactive daughters: Th-228, Ac-224
Dosimetric constants
Mean alpha energy: 0.1216 [MeV]
Mean electron energy: 0.13196 [MeV]
Mean photon energy: 1.36942 [MeV]
Air kerma rate constant, Γ10: 7.391e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 7.394e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 4.062e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 1.948e-14
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
2.114e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 2.194e-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/Pa-228 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/Pa-228 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/Pa-228 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/Pa-228 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.95493e-05 |
5.408e+00 |
X-ray |
|
8.22753e-05 |
2.362e+01 |
X-ray |
|
2.97108e-03 |
2.833e-02 |
X-ray |
|
3.06514e-03 |
1.309e-01 |
X-ray |
|
1.11571e-02 |
2.015e-02 |
X-ray |
|
1.26589e-02 |
6.516e-02 |
X-ray |
|
1.28126e-02 |
3.358e-02 |
X-ray |
|
1.29764e-02 |
2.951e-01 |
X-ray |
|
1.52434e-02 |
1.335e-02 |
X-ray |
|
1.56384e-02 |
6.097e-02 |
X-ray |
|
1.56464e-02 |
1.217e-02 |
X-ray |
|
1.57834e-02 |
2.879e-02 |
X-ray |
|
1.62179e-02 |
1.114e-02 |
X-ray |
|
1.62776e-02 |
2.539e-01 |
X-ray |
|
1.64418e-02 |
1.115e-02 |
X-ray |
|
1.90652e-02 |
5.644e-02 |
X-ray |
|
1.96758e-02 |
1.052e-02 |
X-ray |
|
9.03299e-02 |
2.431e-01 |
X-ray |
|
9.37949e-02 |
3.929e-01 |
X-ray |
|
1.05278e-01 |
4.504e-02 |
X-ray |
|
1.06073e-01 |
8.784e-02 |
X-ray |
|
1.08947e-01 |
1.117e-02 |
X-ray |
|
1.09154e-01 |
2.245e-02 |
X-ray |
|
1.29060e-01 |
4.255e-02 |
Gamma |
|
2.09260e-01 |
2.449e-02 |
Gamma |
|
2.23800e-01 |
1.238e-02 |
Gamma |
|
2.70250e-01 |
3.156e-02 |
Gamma |
|
2.82010e-01 |
1.732e-02 |
Gamma |
|
3.27450e-01 |
2.886e-02 |
Gamma |
|
3.28030e-01 |
2.793e-02 |
Gamma |
|
3.32370e-01 |
1.955e-02 |
Gamma |
|
3.38320e-01 |
7.634e-02 |
Gamma |
|
3.40980e-01 |
1.909e-02 |
Gamma |
|
4.09450e-01 |
9.310e-02 |
Gamma |
|
4.63020e-01 |
2.085e-01 |
Gamma |
|
7.55320e-01 |
1.825e-02 |
Gamma |
|
7.72280e-01 |
2.346e-02 |
Gamma |
|
7.94970e-01 |
3.203e-02 |
Gamma |
|
8.30480e-01 |
2.700e-02 |
Gamma |
|
8.35650e-01 |
3.975e-02 |
Gamma |
|
8.40360e-01 |
1.480e-02 |
Gamma |
|
8.70450e-01 |
1.480e-02 |
Gamma |
|
9.04190e-01 |
2.467e-02 |
Gamma |
|
9.11200e-01 |
2.300e-01 |
Gamma |
|
9.64800e-01 |
1.136e-01 |
Gamma |
|
9.68980e-01 |
1.387e-01 |
Gamma |
|
9.76000e-01 |
1.248e-02 |
Gamma |
|
1.58815e+00 |
3.463e-02 |
Gamma |
|
1.88713e+00 |
2.234e-02 |
Gamma |
|
3.10492e-05 |
1.236e+00 |
Auger electron |
|
5.13393e-05 |
5.690e+00 |
Auger electron |
|
1.25573e-04 |
1.462e+00 |
Auger electron |
|
1.32767e-04 |
6.292e+00 |
Auger electron |
|
1.50462e-04 |
3.620e-02 |
Auger electron |
|
1.86634e-04 |
8.106e-01 |
Auger electron |
|
1.88062e-04 |
3.581e+00 |
Auger electron |
|
4.82508e-04 |
2.302e-01 |
Auger electron |
|
4.96674e-04 |
9.288e-01 |
Auger electron |
|
1.27095e-03 |
1.180e-01 |
Auger electron |
|
1.50945e-03 |
2.782e-01 |
Auger electron |
|
2.09500e-03 |
1.331e-02 |
Conversion electron |
|
2.26356e-03 |
4.676e-01 |
Auger electron |
|
2.31895e-03 |
2.056e+00 |
Auger electron |
|
2.65629e-03 |
7.764e-02 |
Auger electron |
|
2.73391e-03 |
3.533e-01 |
Auger electron |
|
3.31404e-03 |
2.054e-02 |
Auger electron |
|
9.46745e-03 |
1.153e-01 |
Auger electron |
|
9.81490e-03 |
5.420e-01 |
Auger electron |
|
1.24919e-02 |
5.659e-02 |
Auger electron |
|
1.29437e-02 |
2.699e-01 |
Auger electron |
|
1.61070e-02 |
3.172e-02 |
Auger electron |
|
1.89500e-02 |
1.115e-02 |
Conversion electron |
|
2.19370e-02 |
3.037e-02 |
Conversion electron |
|
2.52170e-02 |
2.848e-02 |
Conversion electron |
|
2.78400e-02 |
3.943e-02 |
Conversion electron |
|
2.87520e-02 |
1.087e-01 |
Conversion electron |
|
3.22520e-02 |
3.002e-02 |
Conversion electron |
|
3.27170e-02 |
4.652e-02 |
Conversion electron |
|
3.62170e-02 |
1.235e-02 |
Conversion electron |
|
3.71961e-02 |
1.627e-02 |
Conversion electron |
|
3.72820e-02 |
1.028e-02 |
Conversion electron |
|
3.79800e-02 |
3.116e-01 |
Conversion electron |
|
4.14450e-02 |
2.644e-01 |
Conversion electron |
|
4.46961e-02 |
4.609e-02 |
Conversion electron |
|
4.81961e-02 |
1.257e-02 |
Conversion electron |
|
4.86000e-02 |
1.647e-02 |
Conversion electron |
|
5.37238e-02 |
1.612e-01 |
Conversion electron |
|
5.77600e-02 |
5.566e-02 |
Conversion electron |
|
7.18676e-02 |
1.744e-02 |
Auger electron |
|
1.09280e-01 |
6.470e-02 |
Conversion electron |
|
1.12745e-01 |
4.104e-02 |
Conversion electron |
|
1.13690e-01 |
1.973e-02 |
Conversion electron |
|
1.25024e-01 |
3.032e-02 |
Conversion electron |
|
1.29060e-01 |
1.053e-02 |
Conversion electron |
|
1.71900e-01 |
1.214e-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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