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Radionuclide Dosimetric Data Sheets
Protactinium-235
Summary data
General
Classification
Isotope: Pa-235
Atomic number (Z): 91
Mass number (A): 235
Neutron number (N): 144
Radioactive decay
Decay modes: β-
Half-life: 24.5 [m]
Decay constant: 4.7153e-04 [1/s]
Daughters: U-235m (100.0%), U-235 (0.0101%)
Radioactive daughters: U-235m, U-235
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.48861 [MeV]
Mean photon energy: 0.00079 [MeV]
Air kerma rate constant, Γ10: 3.475e-20 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 3.475e-20 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 7.828e-14 [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-:
7.828e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.266e-16
[Gy·kg/Bq·s]
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-235 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-235 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-235 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.53759e-05 |
8.671e+00 |
X-ray |
|
3.32315e-03 |
3.987e-02 |
X-ray |
|
4.75706e-01 |
9.997e-01 |
Beta |
|
7.19496e-05 |
2.421e+00 |
Auger electron |
|
1.63711e-04 |
1.538e-02 |
Auger electron |
|
1.98156e-04 |
2.229e+00 |
Auger electron |
|
1.99368e-04 |
1.330e+00 |
Auger electron |
|
6.17333e-04 |
7.233e-01 |
Auger electron |
|
2.53604e-03 |
5.763e-01 |
Auger electron |
|
3.07486e-03 |
1.156e-01 |
Auger electron |
|
8.68540e-03 |
7.380e-01 |
Conversion electron |
|
1.29750e-02 |
2.609e-01 |
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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