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Radionuclide Dosimetric Data Sheets
Californium-251
Summary data
General
Classification
Isotope: Cf-251
Atomic number (Z): 98
Mass number (A): 251
Neutron number (N): 153
Radioactive decay
Decay modes: α
Half-life: 900.0 [y]
Decay constant: 2.4406e-11 [1/s]
Daughters: Cm-247 (100.0%)
Radioactive daughters: Cm-247
Dosimetric constants
Mean alpha energy: 5.879 [MeV]
Mean electron energy: 0.17054 [MeV]
Mean photon energy: 0.12453 [MeV]
Air kerma rate constant, Γ10: 1.375e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.375e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 9.692e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 9.419e-13
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
2.732e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.995e-14
[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/Cf-251 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/Cf-251 Summary 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/Cf-251 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.75880e-05 |
1.350e+01 |
X-ray |
|
3.65191e-03 |
9.415e-02 |
X-ray |
|
1.26809e-02 |
1.425e-02 |
X-ray |
|
1.47568e-02 |
2.195e-02 |
X-ray |
|
1.49784e-02 |
1.927e-01 |
X-ray |
|
1.81285e-02 |
4.157e-02 |
X-ray |
|
1.86084e-02 |
1.970e-02 |
X-ray |
|
1.95388e-02 |
1.298e-01 |
X-ray |
|
1.97249e-02 |
1.524e-02 |
X-ray |
|
2.28564e-02 |
3.049e-02 |
X-ray |
|
1.05084e-01 |
1.584e-01 |
X-ray |
|
1.09866e-01 |
2.479e-01 |
X-ray |
|
1.22914e-01 |
2.890e-02 |
X-ray |
|
1.24031e-01 |
5.689e-02 |
X-ray |
|
1.27666e-01 |
1.506e-02 |
X-ray |
|
1.76600e-01 |
1.770e-01 |
Gamma |
|
2.27000e-01 |
6.300e-02 |
Gamma |
|
2.85000e-01 |
1.430e-02 |
Gamma |
|
9.70251e-05 |
3.835e+00 |
Auger electron |
|
1.92024e-04 |
2.012e+00 |
Auger electron |
|
1.92940e-04 |
2.104e-02 |
Auger electron |
|
2.79478e-04 |
3.545e+00 |
Auger electron |
|
6.12235e-04 |
6.045e-01 |
Auger electron |
|
2.04093e-03 |
2.664e-01 |
Auger electron |
|
2.66803e-03 |
1.139e+00 |
Auger electron |
|
3.26170e-03 |
2.519e-01 |
Auger electron |
|
3.96955e-03 |
1.584e-02 |
Auger electron |
|
1.12001e-02 |
2.724e-01 |
Auger electron |
|
1.49732e-02 |
1.440e-01 |
Auger electron |
|
1.87939e-02 |
1.787e-02 |
Auger electron |
|
3.69460e-02 |
1.167e-01 |
Conversion electron |
|
3.77240e-02 |
1.289e-02 |
Conversion electron |
|
4.77400e-02 |
2.991e-02 |
Conversion electron |
|
5.66710e-02 |
3.146e-02 |
Conversion electron |
|
6.15000e-02 |
1.199e-02 |
Conversion electron |
|
9.81400e-02 |
5.046e-01 |
Conversion electron |
|
1.52046e-01 |
1.331e-02 |
Conversion electron |
|
1.52824e-01 |
1.170e-01 |
Conversion electron |
|
1.57606e-01 |
5.666e-02 |
Conversion electron |
|
1.71771e-01 |
5.207e-02 |
Conversion electron |
|
1.76600e-01 |
1.966e-02 |
Conversion electron |
|
2.02446e-01 |
1.538e-01 |
Conversion electron |
|
2.03224e-01 |
2.202e-02 |
Conversion electron |
|
2.08006e-01 |
1.827e-02 |
Conversion electron |
|
2.22171e-01 |
5.144e-02 |
Conversion electron |
|
2.27000e-01 |
1.990e-02 |
Conversion electron |
|
5.56699e+00 |
1.532e-02 |
Alpha |
|
5.63489e+00 |
4.596e-02 |
Alpha |
|
5.65063e+00 |
3.574e-02 |
Alpha |
|
5.67956e+00 |
3.574e-01 |
Alpha |
|
5.74117e+00 |
1.021e-02 |
Alpha |
|
5.76478e+00 |
3.881e-02 |
Alpha |
|
5.79627e+00 |
2.042e-02 |
Alpha |
|
5.81497e+00 |
4.289e-02 |
Alpha |
|
5.85335e+00 |
2.757e-01 |
Alpha |
|
6.01621e+00 |
1.185e-01 |
Alpha |
|
6.07673e+00 |
2.757e-02 |
Alpha |
|
9.02123e-02 |
1.532e-02 |
Alpha recoil |
|
9.13126e-02 |
4.596e-02 |
Alpha recoil |
|
9.15677e-02 |
3.574e-02 |
Alpha recoil |
|
9.20365e-02 |
3.574e-01 |
Alpha recoil |
|
9.30348e-02 |
1.021e-02 |
Alpha recoil |
|
9.34175e-02 |
3.881e-02 |
Alpha recoil |
|
9.39278e-02 |
2.042e-02 |
Alpha recoil |
|
9.42308e-02 |
4.289e-02 |
Alpha recoil |
|
9.48527e-02 |
2.757e-01 |
Alpha recoil |
|
9.74918e-02 |
1.185e-01 |
Alpha recoil |
|
9.84725e-02 |
2.757e-02 |
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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