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Radionuclide Dosimetric Data Sheets
Americium-239
Summary data
General
Classification
Isotope: Am-239
Atomic number (Z): 95
Mass number (A): 239
Neutron number (N): 144
Radioactive decay
Decay modes: α, Electron capture
Half-life: 11.9 [h]
Decay constant: 1.6180e-05 [1/s]
Daughters: Pu-239 (100.0%), Np-235 (0.01%)
Radioactive daughters: Pu-239, Np-235
Dosimetric constants
Mean alpha energy: 0.0005 [MeV]
Mean electron energy: 0.17087 [MeV]
Mean photon energy: 0.24355 [MeV]
Air kerma rate constant, Γ10: 2.941e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.941e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.746e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 8.011e-17
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
2.738e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 3.902e-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/Am-239 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/Am-239 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/Am-239 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.19702e-05 |
3.328e+01 |
X-ray |
|
3.45848e-03 |
2.076e-01 |
X-ray |
|
1.21689e-02 |
2.824e-02 |
X-ray |
|
1.40932e-02 |
4.489e-02 |
X-ray |
|
1.42941e-02 |
3.942e-01 |
X-ray |
|
1.72768e-02 |
8.386e-02 |
X-ray |
|
1.75735e-02 |
2.639e-02 |
X-ray |
|
1.79611e-02 |
1.633e-02 |
X-ray |
|
1.83932e-02 |
2.580e-01 |
X-ray |
|
1.85721e-02 |
2.169e-02 |
X-ray |
|
2.15285e-02 |
5.953e-02 |
X-ray |
|
2.22514e-02 |
1.190e-02 |
X-ray |
|
9.99790e-02 |
3.857e-01 |
X-ray |
|
1.04279e-01 |
6.106e-01 |
X-ray |
|
1.16802e-01 |
7.080e-02 |
X-ray |
|
1.17801e-01 |
1.389e-01 |
X-ray |
|
1.20980e-01 |
1.784e-02 |
X-ray |
|
1.21244e-01 |
3.636e-02 |
X-ray |
|
1.81715e-01 |
1.080e-02 |
Gamma |
|
2.09800e-01 |
3.500e-02 |
Gamma |
|
2.26383e-01 |
3.300e-02 |
Gamma |
|
2.28184e-01 |
1.130e-01 |
Gamma |
|
2.77604e-01 |
1.500e-01 |
Gamma |
|
8.90407e-05 |
9.196e+00 |
Auger electron |
|
1.76445e-04 |
5.780e-02 |
Auger electron |
|
1.93621e-04 |
5.150e+00 |
Auger electron |
|
2.39543e-04 |
8.695e+00 |
Auger electron |
|
6.04093e-04 |
1.650e+00 |
Auger electron |
|
1.70842e-03 |
4.507e-01 |
Auger electron |
|
2.06601e-03 |
1.151e-02 |
Conversion electron |
|
2.56944e-03 |
2.722e+00 |
Auger electron |
|
3.11155e-03 |
5.621e-01 |
Auger electron |
|
3.31010e-03 |
4.781e-01 |
Conversion electron |
|
3.78214e-03 |
3.405e-02 |
Auger electron |
|
7.86000e-03 |
1.718e-01 |
Conversion electron |
|
1.06191e-02 |
5.769e-01 |
Auger electron |
|
1.38501e-02 |
4.315e-02 |
Conversion electron |
|
1.41584e-02 |
2.989e-01 |
Auger electron |
|
1.77355e-02 |
3.640e-02 |
Auger electron |
|
1.84000e-02 |
1.573e-02 |
Conversion electron |
|
2.15410e-02 |
3.802e-02 |
Conversion electron |
|
2.22920e-02 |
1.411e-02 |
Conversion electron |
|
2.62900e-02 |
2.992e-02 |
Conversion electron |
|
2.70410e-02 |
4.255e-02 |
Conversion electron |
|
3.13410e-02 |
3.308e-02 |
Conversion electron |
|
3.49020e-02 |
1.117e-01 |
Conversion electron |
|
3.92020e-02 |
8.959e-02 |
Conversion electron |
|
4.01131e-02 |
1.555e-02 |
Conversion electron |
|
4.48621e-02 |
2.840e-02 |
Conversion electron |
|
4.54700e-02 |
5.269e-02 |
Conversion electron |
|
4.94120e-02 |
1.020e-02 |
Conversion electron |
|
4.97700e-02 |
4.011e-02 |
Conversion electron |
|
5.27231e-02 |
5.764e-02 |
Conversion electron |
|
5.72730e-02 |
2.058e-02 |
Conversion electron |
|
5.93650e-02 |
4.459e-02 |
Conversion electron |
|
6.32911e-02 |
2.664e-02 |
Conversion electron |
|
7.91086e-02 |
2.549e-02 |
Auger electron |
|
8.74500e-02 |
9.775e-02 |
Conversion electron |
|
9.64039e-02 |
1.472e-02 |
Auger electron |
|
1.04033e-01 |
5.832e-02 |
Conversion electron |
|
1.05834e-01 |
2.491e-01 |
Conversion electron |
|
1.55254e-01 |
1.880e-01 |
Conversion electron |
|
1.86678e-01 |
1.725e-02 |
Conversion electron |
|
2.03261e-01 |
1.033e-02 |
Conversion electron |
|
2.05062e-01 |
4.374e-02 |
Conversion electron |
|
2.23634e-01 |
1.197e-02 |
Conversion electron |
|
2.54482e-01 |
3.287e-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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