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Radionuclide Dosimetric Data Sheets
Iodine-123
Summary data
General
Classification
Isotope: I-123
Atomic number (Z): 53
Mass number (A): 123
Neutron number (N): 70
Radioactive decay
Decay modes: Electron capture
Half-life: 13.27 [h]
Decay constant: 1.4509e-05 [1/s]
Daughters: Te-123 (100.0%), Te-123m (0.00444%)
Radioactive daughters: Te-123, Te-123m
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.02818 [MeV]
Mean photon energy: 0.17303 [MeV]
Air kerma rate constant, Γ10: 1.076e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.076e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 4.515e-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-:
4.515e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 2.772e-14
[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/I-123 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/I-123 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/I-123 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.36107e-05 |
1.487e+01 |
X-ray |
|
3.75695e-03 |
3.925e-02 |
X-ray |
|
4.02446e-03 |
2.257e-02 |
X-ray |
|
2.71868e-02 |
2.498e-01 |
X-ray |
|
2.74652e-02 |
4.650e-01 |
X-ray |
|
3.09378e-02 |
4.281e-02 |
X-ray |
|
3.09901e-02 |
8.304e-02 |
X-ray |
|
3.16841e-02 |
1.743e-02 |
X-ray |
|
1.58970e-01 |
8.330e-01 |
Gamma |
|
5.28960e-01 |
1.391e-02 |
Gamma |
|
2.29238e-05 |
7.267e+00 |
Auger electron |
|
2.49261e-05 |
2.427e+00 |
Auger electron |
|
1.21020e-04 |
8.363e-01 |
Auger electron |
|
2.95783e-04 |
1.556e-01 |
Auger electron |
|
4.49494e-04 |
1.870e+00 |
Auger electron |
|
5.41188e-04 |
7.206e-02 |
Auger electron |
|
3.08475e-03 |
7.344e-01 |
Auger electron |
|
3.67886e-03 |
2.080e-01 |
Auger electron |
|
4.29524e-03 |
1.471e-02 |
Auger electron |
|
2.26653e-02 |
8.073e-02 |
Auger electron |
|
2.65056e-02 |
3.556e-02 |
Auger electron |
|
1.27165e-01 |
1.366e-01 |
Conversion electron |
|
1.54056e-01 |
1.634e-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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