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Radionuclide Dosimetric Data Sheets

Americium-246m

Summary data

General

Classification

Isotope:  Am-246m
Atomic number (Z):  95
Mass number (A):  246
Neutron number (N):  151

Radioactive decay

Decay modes:  β-
Half-life:  25.0 [m]
Decay constant:  4.6210e-04 [1/s]
Daughters:  Cm-246 (100.0%)
Radioactive daughters:  Cm-246

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.50326 [MeV]
Mean photon energy:  0.97992 [MeV]
Air kerma rate constant, Γ10:  3.996e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  3.996e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  8.063e-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-:  8.063e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  1.570e-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-246m 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-246m 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-246m 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-246m Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

7.76329e-05

6.896e+00

X-ray

3.65867e-03

4.849e-02

X-ray

1.47568e-02

1.094e-02

X-ray

1.49784e-02

9.602e-02

X-ray

1.81285e-02

2.071e-02

X-ray

1.95388e-02

9.498e-02

X-ray

2.28564e-02

2.231e-02

X-ray

1.05084e-01

1.447e-02

X-ray

1.09866e-01

2.265e-02

X-ray

2.70070e-01

1.022e-02

Gamma

7.34410e-01

1.168e-02

Gamma

7.98800e-01

2.480e-01

Gamma

8.33600e-01

1.786e-02

Gamma

1.03600e+00

1.270e-01

Gamma

1.06204e+00

1.714e-01

Gamma

1.07886e+00

2.778e-01

Gamma

1.08515e+00

1.528e-02

Gamma

2.51223e-01

1.929e-02

Beta

2.75191e-01

1.779e-02

Beta

3.32689e-01

1.199e-02

Beta

3.39193e-01

5.497e-02

Beta

4.21317e-01

1.799e-02

Beta

4.30054e-01

1.399e-01

Beta

4.39892e-01

3.728e-01

Beta

5.17277e-01

6.897e-02

Beta

5.30705e-01

1.609e-01

Beta

8.18389e-01

3.498e-02

Beta

8.46572e-01

3.498e-02

Beta

9.70845e-05

1.954e+00

Auger electron

1.91049e-04

1.040e+00

Auger electron

1.93064e-04

1.073e-02

Auger electron

2.79734e-04

1.810e+00

Auger electron

6.06112e-04

3.028e-01

Auger electron

1.91726e-03

8.615e-02

Auger electron

2.67565e-03

5.835e-01

Auger electron

3.27003e-03

1.292e-01

Auger electron

1.02060e-02

3.577e-02

Conversion electron

1.12766e-02

1.410e-01

Auger electron

1.50513e-02

7.459e-02

Auger electron

1.91240e-02

2.063e-01

Conversion electron

2.39060e-02

1.756e-01

Conversion electron

3.80710e-02

1.085e-01

Conversion electron

4.29000e-02

4.049e-02

Conversion electron

7.54240e-02

1.399e-02

Conversion electron

1.15170e-01

1.498e-02

Conversion electron

1.41210e-01

1.372e-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

 

 

 

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