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Radionuclide Dosimetric Data Sheets
Fermium-252
Summary data
General
Classification
Isotope: Fm-252
Atomic number (Z): 100
Mass number (A): 252
Neutron number (N): 152
Radioactive decay
Decay modes: α, Spontaneus fission
Half-life: 25.39 [h]
Decay constant: 7.5833e-06 [1/s]
Daughters: Cf-248 (100.0%), SF (0.0023%)
Radioactive daughters: Cf-248
Dosimetric constants
Mean alpha energy: 7.1448 [MeV]
Mean electron energy: 0.00637 [MeV]
Mean photon energy: 0.00182 [MeV]
Air kerma rate constant, Γ10: 1.233e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.281e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.146e-12 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 1.145e-12
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
1.021e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 2.916e-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/Fm-252 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/Fm-252 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/Fm-252 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.45992e-05 |
1.646e+00 |
X-ray |
|
3.87083e-03 |
1.248e-02 |
X-ray |
|
1.56809e-02 |
2.383e-02 |
X-ray |
|
2.07498e-02 |
2.694e-02 |
X-ray |
|
1.14521e-04 |
4.448e-01 |
Auger electron |
|
1.90977e-04 |
2.690e-01 |
Auger electron |
|
3.34881e-04 |
4.355e-01 |
Auger electron |
|
6.47270e-04 |
7.631e-02 |
Auger electron |
|
1.98870e-03 |
1.580e-02 |
Auger electron |
|
2.80341e-03 |
1.389e-01 |
Auger electron |
|
3.46500e-03 |
3.346e-02 |
Auger electron |
|
1.18088e-02 |
3.308e-02 |
Auger electron |
|
1.58163e-02 |
1.781e-02 |
Auger electron |
|
1.62880e-02 |
6.359e-02 |
Conversion electron |
|
2.16010e-02 |
5.255e-02 |
Conversion electron |
|
3.64262e-02 |
3.381e-02 |
Conversion electron |
|
4.15300e-02 |
1.247e-02 |
Conversion electron |
|
6.99822e+00 |
1.500e-01 |
Alpha |
|
7.03909e+00 |
8.400e-01 |
Alpha |
|
1.12948e-01 |
1.500e-01 |
Alpha recoil |
|
1.13608e-01 |
8.400e-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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