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Radionuclide Dosimetric Data Sheets

Radon-209

Summary data

General

Classification

Isotope:  Rn-209
Atomic number (Z):  86
Mass number (A):  209
Neutron number (N):  123

Radioactive decay

Decay modes:  α, β+, Electron capture
Half-life:  28.5 [m]
Decay constant:  4.0535e-04 [1/s]
Daughters:  At-209 (83.0%), Po-205 (17.0%)
Radioactive daughters:  At-209, Po-205

Dosimetric constants

Mean alpha energy:  1.0465 [MeV]
Mean electron energy:  0.11671 [MeV]
Mean photon energy:  1.19527 [MeV]
Air kerma rate constant, Γ10:  5.059e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  5.290e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  1.864e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δα:  1.677e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δβ-,β+,e-:  1.870e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  1.915e-13 [Gy·kg/Bq·s]

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/Rn-209 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/Rn-209 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/Rn-209 Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

4.42776e-05

1.079e+01

X-ray

2.62488e-03

4.821e-02

X-ray

1.13036e-02

1.453e-02

X-ray

1.14288e-02

1.279e-01

X-ray

1.37157e-02

2.530e-02

X-ray

1.39286e-02

8.336e-02

X-ray

1.63129e-02

1.759e-02

X-ray

7.92282e-02

2.052e-01

X-ray

8.18531e-02

3.399e-01

X-ray

9.20763e-02

3.830e-02

X-ray

9.26695e-02

7.432e-02

X-ray

9.53262e-02

1.837e-02

X-ray

2.79200e-01

1.107e-02

Gamma

3.37450e-01

1.451e-01

Gamma

3.86360e-01

2.064e-02

Gamma

3.86750e-01

2.064e-02

Gamma

4.08320e-01

5.030e-01

Gamma

4.61410e-01

1.440e-02

Gamma

5.11000e-01

1.195e-01

Annihilation photon

6.72820e-01

3.268e-02

Gamma

6.84900e-01

1.161e-02

Gamma

6.89260e-01

9.674e-02

Gamma

7.45780e-01

2.279e-01

Gamma

7.94720e-01

3.364e-02

Gamma

8.55760e-01

4.869e-02

Gamma

1.03793e+00

4.160e-02

Gamma

1.05453e+00

1.634e-02

Gamma

1.06555e+00

1.698e-02

Gamma

9.78683e-01

3.657e-02

Positron

1.12764e+00

1.828e-02

Positron

3.80342e-05

2.675e+00

Auger electron

1.04853e-04

3.274e+00

Auger electron

1.76535e-04

1.780e+00

Auger electron

4.46763e-04

4.148e-01

Auger electron

1.17447e-03

1.347e-01

Auger electron

2.06558e-03

9.762e-01

Auger electron

2.37646e-03

1.402e-01

Auger electron

8.65794e-03

2.796e-01

Auger electron

1.12984e-02

1.297e-01

Auger electron

1.39676e-02

1.430e-02

Auger electron

6.34792e-02

1.630e-02

Auger electron

2.41382e-01

4.998e-02

Conversion electron

3.12252e-01

1.768e-02

Conversion electron

6.03909e+00

1.693e-01

Alpha

1.17912e-01

1.693e-01

Alpha recoil

 

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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