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Radionuclide Dosimetric Data Sheets

Iridium-188

Summary data

General

Classification

Isotope:  Ir-188
Atomic number (Z):  77
Mass number (A):  188
Neutron number (N):  111

Radioactive decay

Decay modes:  β+, Electron capture
Half-life:  41.5 [h]
Decay constant:  4.6395e-06 [1/s]
Daughters:  Os-188 (100.0%)
Radioactive daughters:  None

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.05084 [MeV]
Mean photon energy:  2.09741 [MeV]
Air kerma rate constant, Γ10:  7.464e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  7.477e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  8.145e-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-:  8.145e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  3.360e-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/Ir-188 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/Ir-188 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/Ir-188 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/Ir-188 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

4.40667e-05

9.851e+00

X-ray

1.92058e-03

4.290e-02

X-ray

8.83249e-03

1.533e-02

X-ray

8.90608e-03

1.352e-01

X-ray

1.03795e-02

9.084e-02

X-ray

1.05947e-02

2.449e-02

X-ray

1.21269e-02

1.731e-02

X-ray

6.16420e-02

2.494e-01

X-ray

6.31890e-02

4.296e-01

X-ray

7.12758e-02

4.664e-02

X-ray

7.16144e-02

9.014e-02

X-ray

7.35200e-02

1.074e-02

X-ray

7.35997e-02

2.088e-02

X-ray

1.55050e-01

2.969e-01

Gamma

3.22910e-01

1.617e-02

Gamma

4.77990e-01

1.470e-01

Gamma

6.33020e-01

1.793e-01

Gamma

6.34910e-01

4.998e-02

Gamma

6.72500e-01

1.441e-02

Gamma

8.24340e-01

1.029e-02

Gamma

8.29420e-01

5.130e-02

Gamma

1.01763e+00

1.058e-02

Gamma

1.09654e+00

1.455e-02

Gamma

1.17459e+00

1.323e-02

Gamma

1.20977e+00

6.909e-02

Gamma

1.43542e+00

1.485e-02

Gamma

1.45228e+00

1.058e-02

Gamma

1.45719e+00

1.749e-02

Gamma

1.46524e+00

1.352e-02

Gamma

1.57448e+00

2.631e-02

Gamma

1.70490e+00

1.044e-02

Gamma

1.71567e+00

6.174e-02

Gamma

1.94408e+00

3.925e-02

Gamma

2.04978e+00

4.983e-02

Gamma

2.05965e+00

7.056e-02

Gamma

2.09690e+00

5.733e-02

Gamma

2.09910e+00

4.704e-02

Gamma

2.19367e+00

2.014e-02

Gamma

2.21459e+00

1.867e-01

Gamma

2.96073e-05

1.917e+00

Auger electron

1.63604e-04

3.273e+00

Auger electron

3.33265e-04

6.507e-01

Auger electron

3.43091e-04

1.313e-01

Auger electron

6.32237e-04

1.864e-01

Auger electron

1.58178e-03

1.568e+00

Auger electron

1.77849e-03

1.227e-01

Auger electron

6.88414e-03

4.838e-01

Auger electron

8.78278e-03

1.921e-01

Auger electron

1.07104e-02

1.883e-02

Auger electron

4.99348e-02

2.463e-02

Auger electron

5.97656e-02

1.305e-02

Auger electron

8.09840e-02

9.618e-02

Conversion electron

1.42100e-01

1.100e-02

Conversion electron

1.42626e-01

5.738e-02

Conversion electron

1.44173e-01

4.272e-02

Conversion electron

1.52598e-01

2.830e-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

 

 

 

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