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Radionuclide Dosimetric Data Sheets
Thallium-198m
Summary data
General
Classification
Isotope: Tl-198m
Atomic number (Z): 81
Mass number (A): 198
Neutron number (N): 117
Radioactive decay
Decay modes: β+, Electron capture, Internal
transition
Half-life: 1.87 [h]
Decay constant: 1.0296e-04 [1/s]
Daughters: Tl-198 (46.0%), Hg-198 (54.0%)
Radioactive daughters: Tl-198
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.20064 [MeV]
Mean photon energy: 1.21682 [MeV]
Air kerma rate constant, Γ10: 5.998e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 6.035e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 3.215e-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-:
3.215e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.950e-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/Tl-198m 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/Tl-198m 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/Tl-198m 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/Tl-198m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.47061e-05 |
1.343e+01 |
X-ray |
|
2.07326e-05 |
8.399e+00 |
X-ray |
|
2.22432e-03 |
4.381e-02 |
X-ray |
|
2.29931e-03 |
2.943e-02 |
X-ray |
|
9.89220e-03 |
1.394e-02 |
X-ray |
|
9.98620e-03 |
1.228e-01 |
X-ray |
|
1.02661e-02 |
8.493e-02 |
X-ray |
|
1.18592e-02 |
9.866e-02 |
X-ray |
|
1.19286e-02 |
2.317e-02 |
X-ray |
|
1.22523e-02 |
4.107e-02 |
X-ray |
|
1.22749e-02 |
1.618e-02 |
X-ray |
|
1.38758e-02 |
1.971e-02 |
X-ray |
|
6.90989e-02 |
1.449e-01 |
X-ray |
|
7.10519e-02 |
8.991e-02 |
X-ray |
|
7.10661e-02 |
2.456e-01 |
X-ray |
|
7.31380e-02 |
1.517e-01 |
X-ray |
|
8.00792e-02 |
2.713e-02 |
X-ray |
|
8.05161e-02 |
5.250e-02 |
X-ray |
|
8.23884e-02 |
1.683e-02 |
X-ray |
|
8.27860e-02 |
1.252e-02 |
X-ray |
|
8.28534e-02 |
3.258e-02 |
X-ray |
|
2.15600e-01 |
1.260e-02 |
Gamma |
|
2.26200e-01 |
5.354e-02 |
Gamma |
|
2.27500e-01 |
1.417e-02 |
Gamma |
|
2.59600e-01 |
2.862e-02 |
Gamma |
|
2.60900e-01 |
1.291e-02 |
Gamma |
|
2.74000e-01 |
1.522e-02 |
Gamma |
|
2.82800e-01 |
2.806e-01 |
Gamma |
|
3.90400e-01 |
1.680e-02 |
Gamma |
|
4.11800e-01 |
5.721e-01 |
Gamma |
|
4.23300e-01 |
1.081e-02 |
Gamma |
|
4.41800e-01 |
2.204e-02 |
Gamma |
|
4.89600e-01 |
4.514e-02 |
Gamma |
|
5.11000e-01 |
1.898e-02 |
Annihilation photon |
|
5.19200e-01 |
3.569e-02 |
Gamma |
|
5.87200e-01 |
5.249e-01 |
Gamma |
|
6.36700e-01 |
5.721e-01 |
Gamma |
|
7.67300e-01 |
1.118e-02 |
Gamma |
|
4.20513e-05 |
3.041e+00 |
Auger electron |
|
4.29923e-05 |
1.848e+00 |
Auger electron |
|
6.99209e-05 |
4.449e+00 |
Auger electron |
|
7.58169e-05 |
2.750e+00 |
Auger electron |
|
1.74345e-04 |
1.440e+00 |
Auger electron |
|
1.74852e-04 |
2.347e+00 |
Auger electron |
|
4.16666e-04 |
3.216e-01 |
Auger electron |
|
4.17903e-04 |
4.957e-01 |
Auger electron |
|
8.19105e-04 |
1.252e-01 |
Auger electron |
|
9.38398e-04 |
1.196e-01 |
Auger electron |
|
1.81066e-03 |
1.203e+00 |
Auger electron |
|
1.85736e-03 |
7.576e-01 |
Auger electron |
|
2.04471e-03 |
1.333e-01 |
Auger electron |
|
2.10278e-03 |
8.914e-02 |
Auger electron |
|
7.70099e-03 |
3.638e-01 |
Auger electron |
|
7.77000e-03 |
3.143e-02 |
Conversion electron |
|
7.79363e-03 |
2.171e-01 |
Auger electron |
|
9.91155e-03 |
1.557e-01 |
Auger electron |
|
1.00830e-02 |
9.435e-02 |
Auger electron |
|
1.21498e-02 |
1.608e-02 |
Auger electron |
|
3.34860e-02 |
1.584e-01 |
Conversion electron |
|
3.54530e-02 |
1.610e-01 |
Conversion electron |
|
4.49031e-02 |
8.406e-02 |
Conversion electron |
|
4.77400e-02 |
2.497e-02 |
Conversion electron |
|
5.57212e-02 |
1.286e-02 |
Auger electron |
|
1.42847e-01 |
3.038e-02 |
Conversion electron |
|
1.73802e-01 |
1.446e-02 |
Conversion electron |
|
1.75102e-01 |
1.930e-01 |
Conversion electron |
|
1.97002e-01 |
1.119e-01 |
Conversion electron |
|
2.45570e-01 |
8.709e-02 |
Conversion electron |
|
2.46154e-01 |
2.241e-02 |
Conversion electron |
|
2.48240e-01 |
8.080e-02 |
Conversion electron |
|
2.57955e-01 |
5.498e-02 |
Conversion electron |
|
2.60900e-01 |
1.753e-02 |
Conversion electron |
|
2.67470e-01 |
1.710e-02 |
Conversion electron |
|
3.28447e-01 |
1.729e-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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