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Radionuclide Dosimetric Data Sheets
Lanthanum-129
Summary data
General
Classification
Isotope: La-129
Atomic number (Z): 57
Mass number (A): 129
Neutron number (N): 72
Radioactive decay
Decay modes: β+, Electron capture
Half-life: 11.6 [m]
Decay constant: 9.9590e-04 [1/s]
Daughters: Ba-129 (92.4%), Ba-129m (7.62%)
Radioactive daughters: Ba-129, Ba-129m
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.61348 [MeV]
Mean photon energy: 0.92118 [MeV]
Air kerma rate constant, Γ10: 1.502e-17 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 3.598e-17 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 9.829e-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-:
9.829e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 1.476e-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/La-129 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/La-129 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/La-129 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/La-129 Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
1.86002e-05 |
8.409e+00 |
X-ray |
|
4.45292e-03 |
2.653e-02 |
X-ray |
|
4.82366e-03 |
1.565e-02 |
X-ray |
|
3.18187e-02 |
1.389e-01 |
X-ray |
|
3.22056e-02 |
2.558e-01 |
X-ray |
|
3.63167e-02 |
2.445e-02 |
X-ray |
|
3.63920e-02 |
4.737e-02 |
X-ray |
|
3.72607e-02 |
1.006e-02 |
X-ray |
|
1.10500e-01 |
1.692e-01 |
Gamma |
|
1.43300e-01 |
1.260e-02 |
Gamma |
|
1.68100e-01 |
1.284e-02 |
Gamma |
|
2.53800e-01 |
8.027e-02 |
Gamma |
|
2.78600e-01 |
2.470e-01 |
Gamma |
|
3.18400e-01 |
2.025e-02 |
Gamma |
|
3.46500e-01 |
5.113e-02 |
Gamma |
|
3.48700e-01 |
1.581e-02 |
Gamma |
|
4.48600e-01 |
5.187e-02 |
Gamma |
|
4.57000e-01 |
8.027e-02 |
Gamma |
|
4.58200e-01 |
2.099e-02 |
Gamma |
|
5.11000e-01 |
1.083e+00 |
Annihilation photon |
|
6.01300e-01 |
1.013e-02 |
Gamma |
|
6.17800e-01 |
1.037e-02 |
Gamma |
|
8.93097e-01 |
1.892e-02 |
Positron |
|
1.00920e+00 |
9.556e-02 |
Positron |
|
1.09093e+00 |
1.468e-01 |
Positron |
|
1.10232e+00 |
3.251e-02 |
Positron |
|
1.16818e+00 |
8.867e-02 |
Positron |
|
1.21918e+00 |
1.084e-01 |
Positron |
|
1.08630e-05 |
1.794e+00 |
Auger electron |
|
2.91100e-05 |
1.487e-02 |
Auger electron |
|
4.69812e-05 |
1.041e+00 |
Auger electron |
|
4.88175e-05 |
2.845e+00 |
Auger electron |
|
1.14476e-04 |
4.111e-01 |
Auger electron |
|
3.41802e-04 |
8.305e-02 |
Auger electron |
|
5.52257e-04 |
9.296e-01 |
Auger electron |
|
6.90577e-04 |
6.844e-02 |
Auger electron |
|
3.56896e-03 |
3.648e-01 |
Auger electron |
|
4.33543e-03 |
1.166e-01 |
Auger electron |
|
2.63448e-02 |
3.406e-02 |
Auger electron |
|
3.09583e-02 |
1.571e-02 |
Auger electron |
|
7.30510e-02 |
1.100e-01 |
Conversion electron |
|
1.04539e-01 |
1.362e-02 |
Conversion electron |
|
2.41151e-01 |
1.276e-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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