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Radionuclide Dosimetric Data Sheets
Iodine-133
Summary data
General
Classification
Isotope: I-133
Atomic number (Z): 53
Mass number (A): 133
Neutron number (N): 80
Radioactive decay
Decay modes: β-
Half-life: 20.8 [h]
Decay constant: 9.2568e-06 [1/s]
Daughters: Xe-133 (97.1%), Xe-133m (2.88%)
Radioactive daughters: Xe-133, Xe-133m
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.41415 [MeV]
Mean photon energy: 0.612 [MeV]
Air kerma rate constant, Γ10: 2.289e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.289e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 6.635e-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-:
6.635e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 9.805e-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-133 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-133 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-133 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-133 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.66175e-05 |
9.710e-02 |
X-ray |
|
5.10530e-01 |
1.827e-02 |
Gamma |
|
5.29872e-01 |
8.700e-01 |
Gamma |
|
7.06578e-01 |
1.505e-02 |
Gamma |
|
8.56278e-01 |
1.244e-02 |
Gamma |
|
8.75329e-01 |
4.507e-02 |
Gamma |
|
1.23644e+00 |
1.505e-02 |
Gamma |
|
1.29822e+00 |
2.349e-02 |
Gamma |
|
1.13448e-01 |
1.262e-02 |
Beta |
|
1.43544e-01 |
3.807e-02 |
Beta |
|
1.65430e-01 |
3.206e-02 |
Beta |
|
3.02890e-01 |
4.208e-02 |
Beta |
|
3.56117e-01 |
1.833e-02 |
Beta |
|
4.45228e-01 |
8.316e-01 |
Beta |
|
5.77790e-01 |
1.042e-02 |
Beta |
|
2.61450e-05 |
1.511e-02 |
Auger electron |
|
3.62355e-05 |
4.619e-02 |
Auger electron |
|
5.05008e-04 |
1.269e-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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