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Radionuclide Dosimetric Data Sheets

Iodine-118m

Summary data

General

Classification

Isotope:  I-118m
Atomic number (Z):  53
Mass number (A):  118
Neutron number (N):  65

Radioactive decay

Decay modes:  β+, Electron capture
Half-life:  8.5 [m]
Decay constant:  1.3591e-03 [1/s]
Daughters:  Te-118 (100.0%)
Radioactive daughters:  Te-118

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  1.10546 [MeV]
Mean photon energy:  3.75127 [MeV]
Air kerma rate constant, Γ10:  1.086e-16 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  1.391e-16 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  1.771e-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-:  1.771e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  6.010e-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-118m 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-118m 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-118m 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-118m Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

1.36107e-05

3.116e+00

X-ray

2.71868e-02

5.261e-02

X-ray

2.74652e-02

9.795e-02

X-ray

3.09901e-02

1.749e-02

X-ray

1.64100e-01

6.519e-02

Gamma

3.29400e-01

1.134e-01

Gamma

4.04800e-01

1.060e-02

Gamma

4.47300e-01

3.074e-02

Gamma

4.96800e-01

1.272e-02

Gamma

5.11000e-01

1.575e+00

Annihilation photon

5.45000e-01

2.173e-02

Gamma

5.51800e-01

2.385e-02

Gamma

5.52000e-01

1.590e-02

Gamma

6.00600e-01

9.328e-01

Gamma

6.05600e-01

1.002e+00

Gamma

6.14300e-01

6.042e-01

Gamma

6.96500e-01

1.272e-02

Gamma

7.19600e-01

1.802e-02

Gamma

7.53200e-01

2.279e-02

Gamma

7.63900e-01

9.699e-02

Gamma

7.70000e-01

1.590e-02

Gamma

7.70000e-01

1.378e-02

Gamma

8.14200e-01

1.113e-02

Gamma

8.18500e-01

2.385e-02

Gamma

8.49700e-01

1.378e-02

Gamma

9.29300e-01

8.798e-02

Gamma

9.38400e-01

4.452e-02

Gamma

9.44500e-01

1.850e-01

Gamma

9.58100e-01

1.219e-02

Gamma

1.01860e+00

1.325e-02

Gamma

1.04140e+00

2.067e-02

Gamma

1.09360e+00

1.314e-01

Gamma

1.14670e+00

1.378e-02

Gamma

1.16190e+00

1.643e-02

Gamma

1.23170e+00

2.014e-02

Gamma

1.25770e+00

2.253e-01

Gamma

1.28700e+00

1.590e-02

Gamma

1.29350e+00

1.484e-02

Gamma

1.31100e+00

1.431e-02

Gamma

1.32520e+00

1.802e-02

Gamma

1.34740e+00

2.120e-02

Gamma

1.36470e+00

2.173e-02

Gamma

1.37040e+00

3.074e-02

Gamma

1.52400e+00

1.325e-02

Gamma

1.87270e+00

1.007e-02

Gamma

1.23159e+00

1.464e-02

Positron

1.24231e+00

2.440e-02

Positron

1.26744e+00

1.083e-02

Positron

1.27036e+00

2.049e-02

Positron

1.28394e+00

2.928e-01

Positron

1.32051e+00

1.561e-02

Positron

1.33551e+00

2.928e-02

Positron

1.35785e+00

1.220e-02

Positron

1.36055e+00

1.659e-01

Positron

1.44662e+00

1.073e-02

Positron

1.51978e+00

1.854e-02

Positron

1.52123e+00

2.342e-02

Positron

1.53983e+00

1.464e-02

Positron

1.54645e+00

2.440e-02

Positron

1.58377e+00

1.659e-02

Positron

1.71937e+00

4.879e-02

Positron

1.87524e+00

2.928e-02

Positron

2.29231e-05

1.523e+00

Auger electron

2.49272e-05

5.083e-01

Auger electron

1.21051e-04

1.751e-01

Auger electron

2.94818e-04

3.221e-02

Auger electron

4.49455e-04

3.922e-01

Auger electron

5.41071e-04

1.511e-02

Auger electron

3.08408e-03

1.541e-01

Auger electron

3.67810e-03

4.362e-02

Auger electron

2.26653e-02

1.701e-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

 

 

 

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