<= Return to MIRDspec isotope database
Radionuclide Dosimetric Data Sheets
Americium-242m
Summary data
General
Classification
Isotope: Am-242m
Atomic number (Z): 95
Mass number (A): 242
Neutron number (N): 147
Radioactive decay
Decay modes: α, Internal transition
Half-life: 141.0 [y]
Decay constant: 1.5578e-10 [1/s]
Daughters: Am-242 (99.6%), Np-238 (0.45%)
Radioactive daughters: Am-242, Np-238
Dosimetric constants
Mean alpha energy: 0.0238 [MeV]
Mean electron energy: 0.04389 [MeV]
Mean photon energy: 0.00562 [MeV]
Air kerma rate constant, Γ10: 5.195e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 5.195e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.085e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 3.813e-15
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
7.032e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 9.004e-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/Am-242m 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-242m 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-242m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.22611e-05 |
8.565e+00 |
X-ray |
|
7.44116e-05 |
1.060e-01 |
X-ray |
|
3.56046e-03 |
5.805e-02 |
X-ray |
|
1.46345e-02 |
8.415e-02 |
X-ray |
|
1.77003e-02 |
1.803e-02 |
X-ray |
|
1.89584e-02 |
9.715e-02 |
X-ray |
|
2.21841e-02 |
2.262e-02 |
X-ray |
|
7.89523e-05 |
3.110e-02 |
Auger electron |
|
9.53701e-05 |
2.397e+00 |
Auger electron |
|
1.84239e-04 |
1.427e-02 |
Auger electron |
|
1.89894e-04 |
1.356e+00 |
Auger electron |
|
1.91160e-04 |
1.605e-02 |
Auger electron |
|
2.09923e-04 |
2.784e-02 |
Auger electron |
|
2.61562e-04 |
2.246e+00 |
Auger electron |
|
6.07434e-04 |
3.526e-01 |
Auger electron |
|
1.61180e-03 |
5.623e-02 |
Auger electron |
|
2.62692e-03 |
7.234e-01 |
Auger electron |
|
3.19175e-03 |
1.547e-01 |
Auger electron |
|
1.10684e-02 |
1.304e-01 |
Auger electron |
|
1.47297e-02 |
6.836e-02 |
Auger electron |
|
2.55680e-02 |
2.539e-01 |
Conversion electron |
|
3.01030e-02 |
2.042e-01 |
Conversion electron |
|
4.39445e-02 |
3.791e-01 |
Conversion electron |
|
4.86300e-02 |
1.537e-01 |
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)
<= Return to MIRDspec isotope database
