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Radionuclide Dosimetric Data Sheets
Iodine-126
Summary data
General
Classification
Isotope: I-126
Atomic number (Z): 53
Mass number (A): 126
Neutron number (N): 73
Radioactive decay
Decay modes: β-, β+, Electron capture
Half-life: 12.93 [d]
Decay constant: 6.2046e-07 [1/s]
Daughters: Te-126 (52.7%), Xe-126 (47.3%)
Radioactive daughters: None
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.16058 [MeV]
Mean photon energy: 0.43535 [MeV]
Air kerma rate constant, Γ10: 1.815e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 1.854e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 2.573e-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-:
2.573e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 6.975e-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-126 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-126 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/I-126 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/I-126 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.36107e-05 |
6.651e+00 |
X-ray |
|
1.66173e-05 |
8.202e-02 |
X-ray |
|
3.75695e-03 |
1.754e-02 |
X-ray |
|
4.02446e-03 |
1.008e-02 |
X-ray |
|
2.71868e-02 |
1.117e-01 |
X-ray |
|
2.74652e-02 |
2.079e-01 |
X-ray |
|
3.09378e-02 |
1.914e-02 |
X-ray |
|
3.09901e-02 |
3.712e-02 |
X-ray |
|
3.88633e-01 |
3.557e-01 |
Gamma |
|
4.91243e-01 |
2.881e-02 |
Gamma |
|
5.11000e-01 |
2.013e-02 |
Annihilation photon |
|
6.66331e-01 |
3.288e-01 |
Gamma |
|
7.53819e-01 |
4.147e-02 |
Gamma |
|
1.11200e-01 |
3.618e-02 |
Beta |
|
2.92434e-01 |
3.339e-01 |
Beta |
|
4.61404e-01 |
1.030e-01 |
Beta |
|
2.29240e-05 |
3.250e+00 |
Auger electron |
|
2.49255e-05 |
1.086e+00 |
Auger electron |
|
2.61316e-05 |
1.276e-02 |
Auger electron |
|
3.62334e-05 |
3.902e-02 |
Auger electron |
|
1.21006e-04 |
3.741e-01 |
Auger electron |
|
2.96021e-04 |
6.971e-02 |
Auger electron |
|
4.49505e-04 |
8.360e-01 |
Auger electron |
|
5.04963e-04 |
1.073e-02 |
Auger electron |
|
5.41223e-04 |
3.222e-02 |
Auger electron |
|
3.08481e-03 |
3.283e-01 |
Auger electron |
|
3.67895e-03 |
9.298e-02 |
Auger electron |
|
2.26653e-02 |
3.609e-02 |
Auger electron |
|
2.65056e-02 |
1.589e-02 |
Auger 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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