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Radionuclide Dosimetric Data Sheets
Uranium-238
Summary data
General
Classification
Isotope: U-238
Atomic number (Z): 92
Mass number (A): 238
Neutron number (N): 146
Radioactive decay
Decay modes: α, Spontaneus fission
Half-life: 4468000000.0 [y]
Decay constant: 4.9161e-18 [1/s]
Daughters: Th-234 (100.0%), SF (5.45e-05%)
Radioactive daughters: Th-234
Dosimetric constants
Mean alpha energy: 4.2584 [MeV]
Mean electron energy: 0.00917 [MeV]
Mean photon energy: 0.00143 [MeV]
Air kerma rate constant, Γ10: 2.037e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.038e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 6.837e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 6.823e-13
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
1.469e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 2.291e-16
[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/U-238 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/U-238 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/U-238 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/U-238 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
8.23171e-05 |
2.156e+00 |
X-ray |
|
3.07062e-03 |
1.194e-02 |
X-ray |
|
1.29764e-02 |
2.506e-02 |
X-ray |
|
1.62776e-02 |
3.036e-02 |
X-ray |
|
5.13398e-05 |
5.190e-01 |
Auger electron |
|
1.33126e-04 |
5.743e-01 |
Auger electron |
|
1.88109e-04 |
3.294e-01 |
Auger electron |
|
4.97239e-04 |
8.433e-02 |
Auger electron |
|
1.77870e-03 |
1.338e-02 |
Auger electron |
|
2.32658e-03 |
1.870e-01 |
Auger electron |
|
2.74420e-03 |
3.224e-02 |
Auger electron |
|
9.94648e-03 |
4.978e-02 |
Auger electron |
|
1.30815e-02 |
2.482e-02 |
Auger electron |
|
2.97700e-02 |
8.042e-02 |
Conversion electron |
|
3.32350e-02 |
7.103e-02 |
Conversion electron |
|
4.55138e-02 |
4.227e-02 |
Conversion electron |
|
4.95500e-02 |
1.460e-02 |
Conversion electron |
|
4.14918e+00 |
2.233e-01 |
Alpha |
|
4.19790e+00 |
7.754e-01 |
Alpha |
|
7.09722e-02 |
2.233e-01 |
Alpha recoil |
|
7.18055e-02 |
7.754e-01 |
Alpha recoil |
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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