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Radionuclide Dosimetric Data Sheets
Thorium-234
Summary data
General
Classification
Isotope: Th-234
Atomic number (Z): 90
Mass number (A): 234
Neutron number (N): 144
Radioactive decay
Decay modes: β-
Half-life: 24.1 [d]
Decay constant: 3.3289e-07 [1/s]
Daughters: Pa-234m (100.0%)
Radioactive daughters: Pa-234m
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.06223 [MeV]
Mean photon energy: 0.01051 [MeV]
Air kerma rate constant, Γ10: 2.868e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.868e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 9.970e-15 [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-:
9.970e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.684e-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-234 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-234 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-234 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-234 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.65007e-05 |
3.490e+00 |
X-ray |
|
3.15978e-03 |
1.982e-02 |
X-ray |
|
1.32994e-02 |
3.949e-02 |
X-ray |
|
1.67859e-02 |
1.785e-02 |
X-ray |
|
6.32900e-02 |
4.838e-02 |
Gamma |
|
9.23800e-02 |
2.812e-02 |
Gamma |
|
9.28000e-02 |
2.772e-02 |
Gamma |
|
2.11758e-02 |
2.899e-02 |
Beta |
|
2.65438e-02 |
7.598e-02 |
Beta |
|
2.66601e-02 |
1.920e-01 |
Beta |
|
5.23776e-02 |
7.029e-01 |
Beta |
|
6.45967e-05 |
8.533e-01 |
Auger electron |
|
1.66015e-04 |
9.221e-01 |
Auger electron |
|
1.94130e-04 |
5.176e-01 |
Auger electron |
|
5.37796e-04 |
1.604e-01 |
Auger electron |
|
1.39233e-03 |
9.564e-02 |
Auger electron |
|
2.37943e-03 |
2.966e-01 |
Auger electron |
|
2.82573e-03 |
5.343e-02 |
Auger electron |
|
9.08800e-03 |
2.616e-02 |
Conversion electron |
|
1.00115e-02 |
6.687e-02 |
Auger electron |
|
1.27470e-02 |
2.558e-02 |
Conversion electron |
|
1.32485e-02 |
3.363e-02 |
Auger electron |
|
1.58606e-02 |
1.304e-02 |
Conversion electron |
|
2.53306e-02 |
1.433e-02 |
Conversion electron |
|
7.12670e-02 |
1.076e-01 |
Conversion electron |
|
7.19780e-02 |
1.148e-02 |
Conversion electron |
|
8.82206e-02 |
2.900e-02 |
Conversion electron |
|
9.23800e-02 |
1.037e-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
MIRDsoft MIRDspecs version 20250101 (www.mirdsoft.org)
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