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Radionuclide Dosimetric Data Sheets

Iridium-186m

Summary data

General

Classification

Isotope:  Ir-186m
Atomic number (Z):  77
Mass number (A):  186
Neutron number (N):  109

Radioactive decay

Decay modes:  β+, Electron capture, Internal transition
Half-life:  1.92 [h]
Decay constant:  1.0028e-04 [1/s]
Daughters:  Os-186 (75.0%), Ir-186 (25.0%)
Radioactive daughters:  Os-186, Ir-186

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.11032 [MeV]
Mean photon energy:  1.25227 [MeV]
Air kerma rate constant, Γ10:  4.732e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  4.974e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  1.768e-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-:  1.768e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  2.006e-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-186m 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-186m 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-186m 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-186m Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

3.93071e-05

7.522e-01

X-ray

4.40806e-05

7.832e+00

X-ray

1.92090e-03

3.411e-02

X-ray

8.83249e-03

1.210e-02

X-ray

8.90608e-03

1.067e-01

X-ray

1.03795e-02

7.704e-02

X-ray

1.05947e-02

1.932e-02

X-ray

1.21269e-02

1.468e-02

X-ray

6.16420e-02

1.886e-01

X-ray

6.31890e-02

3.249e-01

X-ray

7.12758e-02

3.527e-02

X-ray

7.16144e-02

6.818e-02

X-ray

7.35997e-02

1.579e-02

X-ray

1.37140e-01

2.296e-01

Gamma

2.96930e-01

8.572e-02

Gamma

5.11000e-01

1.252e-01

Annihilation photon

5.69630e-01

1.248e-02

Gamma

6.30320e-01

1.562e-01

Gamma

6.36320e-01

1.619e-02

Gamma

6.85130e-01

1.372e-02

Gamma

6.87430e-01

1.210e-02

Gamma

7.12570e-01

2.762e-02

Gamma

7.67460e-01

1.838e-01

Gamma

7.73240e-01

1.172e-01

Gamma

7.83200e-01

1.705e-02

Gamma

8.44080e-01

2.057e-02

Gamma

9.33400e-01

1.705e-02

Gamma

9.38000e-01

1.953e-02

Gamma

9.87030e-01

9.525e-02

Gamma

1.61721e+00

3.619e-02

Gamma

1.71113e+00

1.753e-02

Gamma

1.75440e+00

4.000e-02

Gamma

2.17320e+00

1.133e-02

Gamma

2.18695e+00

2.572e-02

Gamma

9.24496e-01

2.335e-02

Positron

1.20668e+00

1.946e-02

Positron

2.96005e-05

1.523e+00

Auger electron

3.51246e-05

1.839e-01

Auger electron

1.63654e-04

2.604e+00

Auger electron

1.72916e-04

3.135e-01

Auger electron

3.33476e-04

5.172e-01

Auger electron

3.42718e-04

1.043e-01

Auger electron

3.49496e-04

1.343e-02

Auger electron

6.66429e-04

1.333e-01

Auger electron

8.00000e-04

2.500e-01

Conversion electron

1.58242e-03

1.247e+00

Auger electron

1.77953e-03

9.763e-02

Auger electron

6.89554e-03

3.873e-01

Auger electron

8.79443e-03

1.538e-01

Auger electron

1.07220e-02

1.508e-02

Auger electron

4.99348e-02

1.863e-02

Auger electron

6.30740e-02

9.945e-02

Conversion electron

1.24190e-01

1.126e-02

Conversion electron

1.24716e-01

7.684e-02

Conversion electron

1.26263e-01

6.005e-02

Conversion electron

1.34688e-01

3.786e-02

Conversion electron

1.37140e-01

1.084e-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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