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Radionuclide Dosimetric Data Sheets

Actinium-228

Summary data

General

Classification

Isotope:  Ac-228
Atomic number (Z):  89
Mass number (A):  228
Neutron number (N):  139

Radioactive decay

Decay modes:  β-
Half-life:  6.15 [h]
Decay constant:  3.1307e-05 [1/s]
Daughters:  Th-228 (100.0%)
Radioactive daughters:  Th-228

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.44945 [MeV]
Mean photon energy:  0.86714 [MeV]
Air kerma rate constant, Γ10:  3.991e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  3.991e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  7.201e-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-:  7.201e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  1.389e-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-228 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-228 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-228 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-228 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

8.23067e-05

1.018e+01

X-ray

3.06984e-03

5.629e-02

X-ray

1.28126e-02

1.328e-02

X-ray

1.29764e-02

1.167e-01

X-ray

1.56384e-02

2.412e-02

X-ray

1.62776e-02

1.329e-01

X-ray

1.90652e-02

2.954e-02

X-ray

9.03299e-02

1.951e-02

X-ray

9.37949e-02

3.154e-02

X-ray

9.95090e-02

1.260e-02

Gamma

1.29065e-01

2.420e-02

Gamma

2.09253e-01

3.890e-02

Gamma

2.70245e-01

3.460e-02

Gamma

3.28000e-01

2.950e-02

Gamma

3.38320e-01

1.127e-01

Gamma

4.09462e-01

1.920e-02

Gamma

4.63004e-01

4.400e-02

Gamma

7.55315e-01

1.000e-02

Gamma

7.72291e-01

1.490e-02

Gamma

7.94947e-01

4.250e-02

Gamma

8.35710e-01

1.610e-02

Gamma

9.11204e-01

2.580e-01

Gamma

9.64766e-01

4.990e-02

Gamma

9.68971e-01

1.580e-01

Gamma

1.58820e+00

3.220e-02

Gamma

1.63063e+00

1.510e-02

Gamma

1.15275e-01

1.882e-02

Beta

1.26736e-01

2.620e-02

Beta

1.28534e-01

1.198e-02

Beta

1.40493e-01

4.448e-02

Beta

1.43002e-01

1.230e-02

Beta

1.78621e-01

8.554e-02

Beta

3.07533e-01

3.293e-02

Beta

3.13037e-01

5.453e-02

Beta

3.24348e-01

6.330e-02

Beta

3.61960e-01

3.315e-02

Beta

3.82247e-01

3.197e-01

Beta

6.06791e-01

1.247e-01

Beta

7.43906e-01

8.554e-02

Beta

5.13287e-05

2.452e+00

Auger electron

1.33221e-04

2.712e+00

Auger electron

1.50553e-04

1.562e-02

Auger electron

1.88220e-04

1.551e+00

Auger electron

5.01765e-04

4.024e-01

Auger electron

1.60365e-03

9.579e-02

Auger electron

2.32518e-03

8.819e-01

Auger electron

2.74243e-03

1.519e-01

Auger electron

9.94805e-03

2.313e-01

Auger electron

1.30849e-02

1.153e-01

Auger electron

1.62595e-02

1.358e-02

Auger electron

3.79860e-02

2.859e-01

Conversion electron

4.14510e-02

2.425e-01

Conversion electron

5.37298e-02

1.479e-01

Conversion electron

5.77660e-02

5.106e-02

Conversion electron

7.44300e-02

3.545e-02

Conversion electron

7.90310e-02

3.528e-02

Conversion electron

1.09285e-01

3.680e-02

Conversion electron

1.12750e-01

2.334e-02

Conversion electron

1.25029e-01

1.724e-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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