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Radionuclide Dosimetric Data Sheets

Americium-240

Isotope:  Am-240
Atomic number (Z):  95
Mass number (A):  240
Neutron number (N):  145

Decay modes:  α, Electron capture
Half-life:  50.8 [h]
Decay constant:  3.7902e-06 [1/s]
Daughters:  Pu-240 (100.0%), Np-236 (0.00019%)
Radioactive daughters:  Pu-240, Np-236

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.07575 [MeV]
Mean photon energy:  1.03545 [MeV]
Air kerma rate constant, Γ₁₀:  5.430e-17 [Gy·m²/Bq·s]
Air kerma coefficient, K_air:  5.430e-17 [Gy·m²/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δ_wp:  1.214e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δ_α:  0.000e+00 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δ_β-,β+,e-:  1.214e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δ_p:  1.659e-13 [Gy·kg/Bq·s]

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-240 DPK.csv

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-240 Summary Spectrum.csv

 

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-240 Summary Spectrum.csv

 

Energy [MeV]	Yield [#/nt] if > 0.01	Radiation type
7.20114e-05	2.217e+01	X-ray
3.45123e-03	1.450e-01	X-ray
1.21689e-02	2.209e-02	X-ray
1.40932e-02	3.511e-02	X-ray
1.42941e-02	3.083e-01	X-ray
1.72768e-02	6.559e-02	X-ray
1.75735e-02	1.606e-02	X-ray
1.79612e-02	1.277e-02	X-ray
1.83932e-02	2.476e-01	X-ray
1.85721e-02	1.320e-02	X-ray
2.15285e-02	5.714e-02	X-ray
2.22515e-02	1.142e-02	X-ray
9.89000e-02	1.500e-02	Gamma
9.99790e-02	1.883e-01	X-ray
1.04279e-01	2.981e-01	X-ray
1.16802e-01	3.457e-02	X-ray
1.17801e-01	6.782e-02	X-ray
1.21244e-01	1.775e-02	X-ray
8.88800e-01	2.510e-01	Gamma
9.87760e-01	7.320e-01	Gamma
8.90905e-05	6.078e+00	Auger electron
1.76352e-04	3.826e-02	Auger electron
1.91927e-04	3.436e+00	Auger electron
2.36877e-04	5.817e+00	Auger electron
5.77306e-04	9.127e-01	Auger electron
1.66466e-03	3.265e-01	Auger electron
2.55858e-03	1.897e+00	Auger electron
3.09099e-03	3.889e-01	Auger electron
3.74987e-03	2.336e-02	Auger electron
1.06961e-02	4.667e-01	Auger electron
1.42403e-02	2.420e-01	Auger electron
1.78240e-02	2.950e-02	Auger electron
1.97780e-02	1.134e-02	Conversion electron
2.05290e-02	3.159e-01	Conversion electron
2.48290e-02	2.730e-01	Conversion electron
3.83501e-02	1.677e-01	Conversion electron
4.29000e-02	5.983e-02	Conversion electron
7.65290e-02	1.076e-01	Conversion electron
7.91086e-02	1.245e-02	Auger electron
8.08290e-02	7.129e-02	Conversion electron
9.43501e-02	5.190e-02	Conversion electron
9.89000e-02	1.856e-02	Conversion electron

 

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

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

 

 

 

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