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Radionuclide Dosimetric Data Sheets
Iodine-118
Summary data
General
Classification
Isotope: I-118
Atomic number (Z): 53
Mass number (A): 118
Neutron number (N): 65
Radioactive decay
Decay modes: β+, Electron capture
Half-life: 13.7 [m]
Decay constant: 8.4324e-04 [1/s]
Daughters: Te-118 (100.0%)
Radioactive daughters: Te-118
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 1.96453 [MeV]
Mean photon energy: 2.01631 [MeV]
Air kerma rate constant, Γ10: 3.934e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 7.453e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 3.148e-13 [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-:
3.148e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 3.230e-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/I-118 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-118 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-118 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-118 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.36107e-05 |
1.251e+00 |
X-ray |
|
2.71868e-02 |
2.111e-02 |
X-ray |
|
2.74652e-02 |
3.929e-02 |
X-ray |
|
3.51700e-01 |
2.326e-02 |
Gamma |
|
5.11000e-01 |
1.818e+00 |
Annihilation photon |
|
5.45000e-01 |
1.005e-01 |
Gamma |
|
5.51800e-01 |
1.483e-02 |
Gamma |
|
6.00600e-01 |
8.039e-02 |
Gamma |
|
6.05600e-01 |
7.761e-01 |
Gamma |
|
7.41200e-01 |
1.321e-02 |
Gamma |
|
8.76400e-01 |
5.608e-02 |
Gamma |
|
1.15060e+00 |
3.732e-02 |
Gamma |
|
1.25700e+00 |
2.010e-02 |
Gamma |
|
1.33880e+00 |
7.761e-02 |
Gamma |
|
1.41490e+00 |
1.598e-02 |
Gamma |
|
1.46649e+00 |
1.372e-02 |
Positron |
|
1.69231e+00 |
1.652e-02 |
Positron |
|
1.71011e+00 |
1.161e-02 |
Positron |
|
1.72823e+00 |
7.108e-02 |
Positron |
|
1.75311e+00 |
1.902e-02 |
Positron |
|
1.76671e+00 |
2.102e-02 |
Positron |
|
1.83642e+00 |
2.333e-02 |
Positron |
|
1.94734e+00 |
5.807e-02 |
Positron |
|
2.06728e+00 |
3.904e-02 |
Positron |
|
2.10508e+00 |
6.107e-02 |
Positron |
|
2.18307e+00 |
1.001e-02 |
Positron |
|
2.36582e+00 |
3.254e-01 |
Positron |
|
2.63299e+00 |
1.652e-01 |
Positron |
|
2.29232e-05 |
6.111e-01 |
Auger electron |
|
2.49270e-05 |
2.040e-01 |
Auger electron |
|
1.21046e-04 |
7.026e-02 |
Auger electron |
|
2.94919e-04 |
1.294e-02 |
Auger electron |
|
4.49460e-04 |
1.574e-01 |
Auger electron |
|
3.08412e-03 |
6.181e-02 |
Auger electron |
|
3.67815e-03 |
1.750e-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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