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Radionuclide Dosimetric Data Sheets
Antimony-120m
Summary data
General
Classification
Isotope: Sb-120m
Atomic number (Z): 51
Mass number (A): 120
Neutron number (N): 69
Radioactive decay
Decay modes: Electron capture
Half-life: 5.76 [d]
Decay constant: 1.3928e-06 [1/s]
Daughters: Sn-120 (100.0%)
Radioactive daughters: None
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.04492 [MeV]
Mean photon energy: 2.46628 [MeV]
Air kerma rate constant, Γ10: 9.267e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 9.267e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 7.197e-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-:
7.197e-15 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 3.951e-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/Sb-120m 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/Sb-120m Summary 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/Sb-120m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.08543e-05 |
1.810e+01 |
X-ray |
|
3.43219e-03 |
3.983e-02 |
X-ray |
|
3.65722e-03 |
2.275e-02 |
X-ray |
|
2.50232e-02 |
2.761e-01 |
X-ray |
|
2.52572e-02 |
5.165e-01 |
X-ray |
|
2.84307e-02 |
4.660e-02 |
X-ray |
|
2.84736e-02 |
9.048e-02 |
X-ray |
|
2.90882e-02 |
1.865e-02 |
X-ray |
|
8.98000e-02 |
7.950e-01 |
Gamma |
|
1.97300e-01 |
8.700e-01 |
Gamma |
|
1.02330e+00 |
9.940e-01 |
Gamma |
|
1.17170e+00 |
1.000e+00 |
Gamma |
|
1.13317e-05 |
8.947e+00 |
Auger electron |
|
3.03591e-05 |
3.082e+00 |
Auger electron |
|
1.23829e-04 |
9.959e-01 |
Auger electron |
|
2.73652e-04 |
1.807e-01 |
Auger electron |
|
3.96354e-04 |
2.236e+00 |
Auger electron |
|
4.70388e-04 |
5.098e-02 |
Auger electron |
|
2.84954e-03 |
8.824e-01 |
Auger electron |
|
3.36656e-03 |
2.275e-01 |
Auger electron |
|
3.90303e-03 |
1.509e-02 |
Auger electron |
|
2.09334e-02 |
1.041e-01 |
Auger electron |
|
2.44171e-02 |
4.433e-02 |
Auger electron |
|
6.06160e-02 |
1.692e-01 |
Conversion electron |
|
8.53597e-02 |
1.668e-02 |
Conversion electron |
|
1.68116e-01 |
1.036e-01 |
Conversion electron |
|
1.92860e-01 |
1.050e-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
MIRDsoft MIRDspecs version 20250101 (www.mirdsoft.org)
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