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Radionuclide Dosimetric Data Sheets

Radium-226

Isotope:  Ra-226
Atomic number (Z):  88
Mass number (A):  226
Neutron number (N):  138

Decay modes:  α
Half-life:  1600.0 [y]
Decay constant:  1.3728e-11 [1/s]
Daughters:  Rn-222 (100.0%)
Radioactive daughters:  Rn-222

Mean alpha energy:  4.8602 [MeV]
Mean electron energy:  0.00391 [MeV]
Mean photon energy:  0.00739 [MeV]
Air kerma rate constant, Γ₁₀:  5.227e-19 [Gy·m²/Bq·s]
Air kerma coefficient, K_air:  5.227e-19 [Gy·m²/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δ_wp:  7.793e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δ_α:  7.787e-13 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δ_β-,β+,e-:  6.265e-16 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δ_p:  1.184e-15 [Gy·kg/Bq·s]

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/Ra-226 DPK.csv

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/Ra-226 Summary Spectrum.csv

 

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/Ra-226 Summary Spectrum.csv

 

Energy [MeV]	Yield [#/nt] if > 0.01	Radiation type
5.01098e-05	2.689e-01	X-ray
1.86211e-01	3.590e-02	Gamma
3.69480e-05	6.922e-02	Auger electron
1.13514e-04	7.938e-02	Auger electron
1.80400e-04	4.401e-02	Auger electron
4.65740e-04	1.076e-02	Auger electron
2.13122e-03	2.382e-02	Auger electron
4.60146e+00	5.550e-02	Alpha
4.78437e+00	9.444e-01	Alpha
8.29630e-02	5.550e-02	Alpha recoil
8.62609e-02	9.444e-01	Alpha recoil

 

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

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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