<= Return to MIRDspec isotope database

Radionuclide Dosimetric Data Sheets

Antimony-125

Isotope:  Sb-125
Atomic number (Z):  51
Mass number (A):  125
Neutron number (N):  74

Decay modes:  β-
Half-life:  2.759 [y]
Decay constant:  7.9625e-09 [1/s]
Daughters:  Te-125m (23.1%), Te-125 (76.9%)
Radioactive daughters:  Te-125m

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.10098 [MeV]
Mean photon energy:  0.43731 [MeV]
Air kerma rate constant, Γ₁₀:  1.939e-17 [Gy·m²/Bq·s]
Air kerma coefficient, K_air:  1.939e-17 [Gy·m²/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δ_wp:  1.618e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for alphas, Δ_α:  0.000e+00 [Gy·kg/Bq·s]
Equilibrium dose constant for betas/electrons, Δ_β-,β+,e-:  1.618e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δ_p:  7.006e-14 [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/Sb-125 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/Sb-125 Summary Spectrum.csv

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/Sb-125 Beta 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/Sb-125 Summary Spectrum.csv

 

Energy [MeV]	Yield [#/nt] if > 0.01	Radiation type
1.36106e-05	8.494e+00	X-ray
3.75695e-03	2.251e-02	X-ray
4.02446e-03	1.311e-02	X-ray
2.71868e-02	1.427e-01	X-ray
2.74652e-02	2.656e-01	X-ray
3.09378e-02	2.446e-02	X-ray
3.09901e-02	4.744e-02	X-ray
3.54890e-02	4.530e-02	Gamma
1.76314e-01	6.887e-02	Gamma
3.80452e-01	1.527e-02	Gamma
4.27874e-01	2.980e-01	Gamma
4.63365e-01	1.056e-01	Gamma
6.00597e-01	1.777e-01	Gamma
6.06713e-01	5.015e-02	Gamma
6.35950e-01	1.129e-01	Gamma
6.71441e-01	1.803e-02	Gamma
2.49115e-02	1.345e-01	Beta
3.30208e-02	5.763e-02	Beta
3.47441e-02	1.792e-01	Beta
6.74757e-02	1.611e-02	Beta
8.69245e-02	4.041e-01	Beta
1.34460e-01	7.196e-02	Beta
2.15426e-01	1.354e-01	Beta
2.29222e-05	4.151e+00	Auger electron
2.49325e-05	1.384e+00	Auger electron
1.21155e-04	4.762e-01	Auger electron
2.93121e-04	8.683e-02	Auger electron
4.49385e-04	1.071e+00	Auger electron
5.40849e-04	4.123e-02	Auger electron
3.08384e-03	4.208e-01	Auger electron
3.67776e-03	1.192e-01	Auger electron
3.68400e-03	5.480e-01	Conversion electron
2.26653e-02	4.612e-02	Auger electron
2.65056e-02	2.031e-02	Auger electron
3.05748e-02	6.569e-02	Conversion electron
3.46741e-02	1.495e-02	Conversion electron

 

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

 

 

 

MIRDsoft MIRDspecs version 20250101 (www.mirdsoft.org)

<= Return to MIRDspec isotope database