<= Return to MIRDspec isotope database
Radionuclide Dosimetric Data Sheets
Thallium-194m
Summary data
General
Classification
Isotope: Tl-194m
Atomic number (Z): 81
Mass number (A): 194
Neutron number (N): 113
Radioactive decay
Decay modes: β+, Electron capture
Half-life: 32.8 [m]
Decay constant: 3.5221e-04 [1/s]
Daughters: Hg-194 (100.0%)
Radioactive daughters: Hg-194
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.30367 [MeV]
Mean photon energy: 2.52177 [MeV]
Air kerma rate constant, Γ10: 9.630e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.028e-16 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 4.865e-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-:
4.865e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 4.040e-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-194m 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-194m 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-194m 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-194m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.47060e-05 |
1.989e+01 |
X-ray |
|
2.22424e-03 |
6.489e-02 |
X-ray |
|
8.75019e-03 |
1.178e-02 |
X-ray |
|
9.89221e-03 |
2.056e-02 |
X-ray |
|
9.98619e-03 |
1.811e-01 |
X-ray |
|
1.18592e-02 |
1.448e-01 |
X-ray |
|
1.19286e-02 |
3.418e-02 |
X-ray |
|
1.38758e-02 |
2.892e-02 |
X-ray |
|
6.90989e-02 |
2.545e-01 |
X-ray |
|
7.10661e-02 |
4.313e-01 |
X-ray |
|
8.00792e-02 |
4.764e-02 |
X-ray |
|
8.05161e-02 |
9.221e-02 |
X-ray |
|
8.26796e-02 |
1.123e-02 |
X-ray |
|
8.27860e-02 |
2.200e-02 |
X-ray |
|
9.69000e-02 |
7.600e-02 |
Gamma |
|
1.10960e-01 |
6.308e-02 |
Gamma |
|
2.08900e-01 |
6.080e-02 |
Gamma |
|
2.27980e-01 |
6.536e-02 |
Gamma |
|
2.33100e-01 |
2.052e-02 |
Gamma |
|
2.55400e-01 |
9.120e-02 |
Gamma |
|
2.84000e-01 |
1.824e-02 |
Gamma |
|
2.98100e-01 |
2.052e-02 |
Gamma |
|
3.19800e-01 |
3.876e-02 |
Gamma |
|
3.52200e-01 |
1.672e-02 |
Gamma |
|
3.66500e-01 |
1.748e-02 |
Gamma |
|
3.80500e-01 |
1.368e-02 |
Gamma |
|
4.28200e-01 |
9.880e-01 |
Gamma |
|
4.46500e-01 |
2.812e-02 |
Gamma |
|
4.51000e-01 |
4.940e-02 |
Gamma |
|
4.62500e-01 |
4.560e-02 |
Gamma |
|
4.64500e-01 |
2.280e-02 |
Gamma |
|
5.10900e-01 |
8.360e-02 |
Gamma |
|
5.11000e-01 |
3.343e-01 |
Annihilation photon |
|
5.53200e-01 |
4.560e-02 |
Gamma |
|
6.00500e-01 |
1.672e-02 |
Gamma |
|
6.36300e-01 |
9.880e-01 |
Gamma |
|
6.50300e-01 |
6.840e-02 |
Gamma |
|
6.64200e-01 |
1.140e-02 |
Gamma |
|
7.02200e-01 |
1.216e-02 |
Gamma |
|
7.11000e-01 |
1.292e-02 |
Gamma |
|
7.19800e-01 |
1.368e-02 |
Gamma |
|
7.35000e-01 |
2.204e-01 |
Gamma |
|
7.49000e-01 |
7.600e-01 |
Gamma |
|
1.55030e+00 |
1.748e-02 |
Gamma |
|
9.87608e-01 |
2.224e-02 |
Positron |
|
1.02722e+00 |
1.516e-02 |
Positron |
|
1.13246e+00 |
1.718e-02 |
Positron |
|
1.23443e+00 |
7.075e-02 |
Positron |
|
1.28417e+00 |
2.729e-02 |
Positron |
|
4.20514e-05 |
4.503e+00 |
Auger electron |
|
6.99376e-05 |
6.587e+00 |
Auger electron |
|
1.74851e-04 |
3.474e+00 |
Auger electron |
|
4.18130e-04 |
7.333e-01 |
Auger electron |
|
9.13696e-04 |
1.909e-01 |
Auger electron |
|
1.81038e-03 |
1.781e+00 |
Auger electron |
|
2.04422e-03 |
1.973e-01 |
Auger electron |
|
7.70415e-03 |
5.377e-01 |
Auger electron |
|
9.91521e-03 |
2.301e-01 |
Auger electron |
|
1.21544e-02 |
2.377e-02 |
Auger electron |
|
1.35470e-02 |
4.678e-02 |
Conversion electron |
|
1.55470e-02 |
4.287e-02 |
Conversion electron |
|
2.76070e-02 |
1.655e-02 |
Conversion electron |
|
5.57212e-02 |
2.260e-02 |
Auger electron |
|
6.69357e-02 |
1.223e-02 |
Auger electron |
|
8.26460e-02 |
1.765e-01 |
Conversion electron |
|
8.46130e-02 |
1.465e-01 |
Conversion electron |
|
9.40631e-02 |
8.693e-02 |
Conversion electron |
|
9.69000e-02 |
2.592e-02 |
Conversion electron |
|
1.44627e-01 |
2.254e-02 |
Conversion electron |
|
1.72047e-01 |
2.639e-02 |
Conversion electron |
|
3.44847e-01 |
2.734e-02 |
Conversion electron |
|
5.52947e-01 |
1.176e-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)
<= Return to MIRDspec isotope database
