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Radionuclide Dosimetric Data Sheets

Actinium-232

Summary data

General

Classification

Isotope:  Ac-232
Atomic number (Z):  89
Mass number (A):  232
Neutron number (N):  143

Radioactive decay

Decay modes:  β-
Half-life:  119.0 [s]
Decay constant:  5.8248e-03 [1/s]
Daughters:  Th-232 (100.0%)
Radioactive daughters:  Th-232

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.97069 [MeV]
Mean photon energy:  1.15279 [MeV]
Air kerma rate constant, Γ10:  4.356e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  4.356e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  1.555e-13 [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-:  1.555e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  1.847e-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/Ac-232 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/Ac-232 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/Ac-232 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/Ac-232 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

8.23177e-05

6.749e+00

X-ray

3.07076e-03

3.736e-02

X-ray

1.29764e-02

7.802e-02

X-ray

1.56384e-02

1.612e-02

X-ray

1.62776e-02

9.526e-02

X-ray

1.90652e-02

2.117e-02

X-ray

6.12000e-01

5.049e-02

Gamma

6.65000e-01

1.530e-01

Gamma

7.14400e-01

2.754e-02

Gamma

7.35800e-01

2.448e-02

Gamma

7.85200e-01

1.377e-02

Gamma

1.02350e+00

1.989e-02

Gamma

1.02810e+00

1.224e-02

Gamma

1.05630e+00

1.071e-02

Gamma

1.07290e+00

4.284e-02

Gamma

1.07750e+00

2.142e-02

Gamma

1.38800e+00

3.366e-02

Gamma

1.43700e+00

1.530e-02

Gamma

1.59300e+00

2.448e-02

Gamma

1.64200e+00

3.519e-02

Gamma

1.81500e+00

1.989e-02

Gamma

1.83000e+00

4.590e-02

Gamma

1.88000e+00

1.377e-02

Gamma

1.89900e+00

8.874e-02

Gamma

1.94800e+00

5.202e-02

Gamma

1.95900e+00

5.355e-02

Gamma

1.97800e+00

3.825e-02

Gamma

2.00800e+00

3.672e-02

Gamma

5.91151e-01

8.946e-02

Beta

6.03172e-01

5.964e-02

Beta

6.15217e-01

1.392e-01

Beta

6.42603e-01

5.964e-02

Beta

7.39339e-01

5.964e-02

Beta

8.23340e-01

4.871e-02

Beta

9.20218e-01

1.093e-02

Beta

9.53328e-01

5.169e-02

Beta

9.71659e-01

1.193e-02

Beta

9.72158e-01

2.087e-02

Beta

9.74071e-01

1.988e-02

Beta

1.05536e+00

5.268e-02

Beta

1.09407e+00

3.877e-02

Beta

1.12373e+00

1.809e-01

Beta

1.42374e+00

1.491e-01

Beta

5.13379e-05

1.625e+00

Auger electron

1.33159e-04

1.798e+00

Auger electron

1.50551e-04

1.035e-02

Auger electron

1.88130e-04

1.031e+00

Auger electron

4.98039e-04

2.642e-01

Auger electron

1.76467e-03

4.332e-02

Auger electron

2.32671e-03

5.852e-01

Auger electron

2.74436e-03

1.009e-01

Auger electron

9.95391e-03

1.556e-01

Auger electron

1.30895e-02

7.761e-02

Auger electron

2.95890e-02

2.244e-01

Conversion electron

3.30540e-02

1.984e-01

Conversion electron

4.53328e-02

1.180e-01

Conversion electron

4.93690e-02

4.075e-02

Conversion electron

9.29200e-02

2.564e-02

Conversion electron

9.63850e-02

1.722e-02

Conversion electron

1.08664e-01

1.221e-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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