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Radionuclide Dosimetric Data Sheets

Thorium-233

Summary data

General

Classification

Isotope:  Th-233
Atomic number (Z):  90
Mass number (A):  233
Neutron number (N):  143

Radioactive decay

Decay modes:  β-
Half-life:  22.3 [m]
Decay constant:  5.1805e-04 [1/s]
Daughters:  Pa-233 (100.0%)
Radioactive daughters:  Pa-233

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.41398 [MeV]
Mean photon energy:  0.03748 [MeV]
Air kerma rate constant, Γ10:  3.750e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  3.750e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  6.633e-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-:  6.633e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  6.005e-15 [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/Th-233 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/Th-233 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/Th-233 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/Th-233 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

7.64276e-05

9.439e+00

X-ray

3.21491e-03

4.331e-02

X-ray

1.32994e-02

3.466e-02

X-ray

1.67859e-02

2.631e-02

X-ray

2.93600e-02

2.497e-02

Gamma

8.64800e-02

2.757e-02

Gamma

4.59222e-01

1.372e-02

Gamma

1.39626e-01

1.535e-02

Beta

2.10594e-01

1.652e-02

Beta

2.47903e-01

1.147e-02

Beta

3.77828e-01

1.555e-01

Beta

4.11314e-01

4.859e-01

Beta

4.13859e-01

2.915e-01

Beta

6.41897e-05

2.385e+00

Auger electron

1.57147e-04

1.586e-02

Auger electron

1.77162e-04

2.437e+00

Auger electron

2.00725e-04

1.409e+00

Auger electron

6.11597e-04

8.158e-01

Auger electron

1.27424e-03

4.213e-02

Auger electron

2.44911e-03

6.452e-01

Auger electron

2.52060e-03

3.835e-01

Conversion electron

2.94787e-03

1.218e-01

Auger electron

4.06060e-03

1.398e-01

Conversion electron

6.68000e-03

1.363e-01

Conversion electron

8.22000e-03

5.009e-02

Conversion electron

8.24700e-03

1.243e-02

Conversion electron

8.95800e-03

2.016e-02

Conversion electron

9.96406e-03

5.837e-02

Auger electron

1.26170e-02

2.546e-02

Conversion electron

1.31886e-02

2.934e-02

Auger electron

2.52006e-02

1.497e-02

Conversion electron

3.67080e-02

3.751e-02

Conversion electron

4.03670e-02

3.149e-02

Conversion electron

5.29506e-02

1.941e-02

Conversion electron

6.53670e-02

1.333e-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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