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Radionuclide Dosimetric Data Sheets
Thorium-224
Summary data
General
Classification
Isotope: Th-224
Atomic number (Z): 90
Mass number (A): 224
Neutron number (N): 134
Radioactive decay
Decay modes: α
Half-life: 1.05 [s]
Decay constant: 6.6014e-01 [1/s]
Daughters: Ra-220 (100.0%)
Radioactive daughters: Ra-220
Dosimetric constants
Mean alpha energy: 7.2635 [MeV]
Mean electron energy: 0.0129 [MeV]
Mean photon energy: 0.02318 [MeV]
Air kerma rate constant, Γ10: 1.658e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.658e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.166e-12 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα: 1.164e-12
[Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:
2.067e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 3.714e-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-224 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-224 Summary 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-224 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
7.12300e-05 |
9.072e-01 |
X-ray |
|
1.53013e-02 |
1.230e-02 |
X-ray |
|
1.77000e-01 |
9.000e-02 |
Gamma |
|
2.57853e-05 |
2.493e-01 |
Auger electron |
|
1.20936e-04 |
2.525e-01 |
Auger electron |
|
1.81479e-04 |
1.436e-01 |
Auger electron |
|
4.78782e-04 |
3.631e-02 |
Auger electron |
|
2.22650e-03 |
7.967e-02 |
Auger electron |
|
2.60098e-03 |
1.285e-02 |
Auger electron |
|
9.56968e-03 |
2.149e-02 |
Auger electron |
|
1.25097e-02 |
1.044e-02 |
Auger electron |
|
7.26800e-02 |
1.826e-02 |
Conversion electron |
|
1.58440e-01 |
2.843e-02 |
Conversion electron |
|
1.61544e-01 |
1.618e-02 |
Conversion electron |
|
1.73226e-01 |
1.314e-02 |
Conversion electron |
|
6.76794e+00 |
1.206e-02 |
Alpha |
|
6.99831e+00 |
1.910e-01 |
Alpha |
|
7.17349e+00 |
7.940e-01 |
Alpha |
|
1.23133e-01 |
1.206e-02 |
Alpha recoil |
|
1.27325e-01 |
1.910e-01 |
Alpha recoil |
|
1.30512e-01 |
7.940e-01 |
Alpha recoil |
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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