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Radionuclide Dosimetric Data Sheets
Americium-244
Summary data
General
Classification
Isotope: Am-244
Atomic number (Z): 95
Mass number (A): 244
Neutron number (N): 149
Radioactive decay
Decay modes: β-
Half-life: 10.1 [h]
Decay constant: 1.9063e-05 [1/s]
Daughters: Cm-244 (100.0%)
Radioactive daughters: Cm-244
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.33295 [MeV]
Mean photon energy: 0.80522 [MeV]
Air kerma rate constant, Γ10: 4.737e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 4.737e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 5.334e-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-:
5.334e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.290e-13
[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-244 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-244 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/Am-244 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/Am-244 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.76572e-05 |
2.385e+01 |
X-ray |
|
3.66381e-03 |
1.683e-01 |
X-ray |
|
1.26809e-02 |
2.319e-02 |
X-ray |
|
1.47568e-02 |
3.574e-02 |
X-ray |
|
1.49784e-02 |
3.137e-01 |
X-ray |
|
1.74629e-02 |
1.116e-02 |
X-ray |
|
1.81285e-02 |
6.767e-02 |
X-ray |
|
1.88688e-02 |
1.366e-02 |
X-ray |
|
1.95388e-02 |
3.887e-01 |
X-ray |
|
2.28563e-02 |
9.131e-02 |
X-ray |
|
2.36395e-02 |
1.895e-02 |
X-ray |
|
9.93830e-02 |
4.600e-02 |
Gamma |
|
1.05084e-01 |
2.225e-02 |
X-ray |
|
1.09866e-01 |
3.482e-02 |
X-ray |
|
1.53863e-01 |
1.640e-01 |
Gamma |
|
7.43971e-01 |
6.600e-01 |
Gamma |
|
8.97848e-01 |
2.800e-01 |
Gamma |
|
1.09603e-01 |
1.000e+00 |
Beta |
|
9.71097e-05 |
6.750e+00 |
Auger electron |
|
1.90631e-04 |
3.619e+00 |
Auger electron |
|
1.93199e-04 |
3.707e-02 |
Auger electron |
|
2.80409e-04 |
6.257e+00 |
Auger electron |
|
6.11615e-04 |
1.042e+00 |
Auger electron |
|
1.82015e-03 |
2.452e-01 |
Auger electron |
|
2.68128e-03 |
2.018e+00 |
Auger electron |
|
3.27639e-03 |
4.472e-01 |
Auger electron |
|
3.98677e-03 |
2.817e-02 |
Auger electron |
|
1.14002e-02 |
4.854e-01 |
Auger electron |
|
1.51829e-02 |
2.571e-01 |
Auger electron |
|
1.84110e-02 |
1.477e-02 |
Conversion electron |
|
1.90142e-02 |
3.201e-02 |
Auger electron |
|
1.91890e-02 |
3.883e-01 |
Conversion electron |
|
2.39710e-02 |
3.303e-01 |
Conversion electron |
|
2.50030e-02 |
2.867e-02 |
Conversion electron |
|
3.81360e-02 |
2.042e-01 |
Conversion electron |
|
4.29650e-02 |
7.617e-02 |
Conversion electron |
|
7.48290e-02 |
2.123e-02 |
Conversion electron |
|
7.56070e-02 |
3.841e-01 |
Conversion electron |
|
8.03890e-02 |
2.448e-01 |
Conversion electron |
|
9.45540e-02 |
1.827e-01 |
Conversion electron |
|
9.93830e-02 |
6.864e-02 |
Conversion electron |
|
1.29309e-01 |
1.813e-02 |
Conversion electron |
|
1.30087e-01 |
1.967e-01 |
Conversion electron |
|
1.34869e-01 |
1.026e-01 |
Conversion electron |
|
1.49034e-01 |
8.851e-02 |
Conversion electron |
|
1.53863e-01 |
3.340e-02 |
Conversion electron |
|
6.15111e-01 |
4.316e-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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