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Radionuclide Dosimetric Data Sheets
Cesium-134m
Summary data
General
Classification
Isotope: Cs-134m
Atomic number (Z): 55
Mass number (A): 134
Neutron number (N): 79
Radioactive decay
Decay modes: Internal transition
Half-life: 2.903 [h]
Decay constant: 6.6325e-05 [1/s]
Daughters: Cs-134 (100.0%)
Radioactive daughters: Cs-134
Dosimetric constants
Mean alpha energy: 0.0 [MeV]
Mean electron energy: 0.11216 [MeV]
Mean photon energy: 0.02725 [MeV]
Air kerma rate constant, Γ10: 2.671e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair: 2.671e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or
electrons), Δwp: 1.797e-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-:
1.797e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp: 4.366e-15
[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/Cs-134m 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/Cs-134m 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/Cs-134m Summary Spectrum.csv
|
Energy [MeV] |
Yield [#/nt] if > 0.01 |
Radiation type |
|
2.18867e-05 |
2.128e+01 |
X-ray |
|
4.27312e-03 |
5.260e-02 |
X-ray |
|
4.61551e-03 |
4.204e-02 |
X-ray |
|
4.62540e-03 |
1.025e-02 |
X-ray |
|
4.69420e-03 |
1.601e-02 |
X-ray |
|
1.12420e-02 |
1.084e-02 |
Gamma |
|
3.06218e-02 |
8.942e-02 |
X-ray |
|
3.09789e-02 |
1.651e-01 |
X-ray |
|
3.49256e-02 |
1.564e-02 |
X-ray |
|
3.49944e-02 |
3.032e-02 |
X-ray |
|
1.27502e-01 |
1.260e-01 |
Gamma |
|
2.17445e-05 |
2.950e+00 |
Auger electron |
|
4.16121e-05 |
1.006e+01 |
Auger electron |
|
1.21150e-04 |
1.339e+00 |
Auger electron |
|
3.63463e-04 |
4.648e-01 |
Auger electron |
|
5.31340e-04 |
2.605e+00 |
Auger electron |
|
6.60183e-04 |
1.727e-01 |
Auger electron |
|
3.51874e-03 |
1.013e+00 |
Auger electron |
|
4.24795e-03 |
3.145e-01 |
Auger electron |
|
5.01119e-03 |
2.455e-02 |
Auger electron |
|
5.55710e-03 |
6.505e-01 |
Conversion electron |
|
5.87880e-03 |
8.239e-02 |
Conversion electron |
|
6.23590e-03 |
5.021e-02 |
Conversion electron |
|
1.02513e-02 |
1.616e-01 |
Conversion electron |
|
1.12420e-02 |
4.180e-02 |
Conversion electron |
|
2.53980e-02 |
2.345e-02 |
Auger electron |
|
2.98089e-02 |
1.066e-02 |
Auger electron |
|
9.15170e-02 |
3.443e-01 |
Conversion electron |
|
1.21817e-01 |
2.982e-02 |
Conversion electron |
|
1.22139e-01 |
1.980e-01 |
Conversion electron |
|
1.22496e-01 |
1.856e-01 |
Conversion electron |
|
1.26511e-01 |
9.331e-02 |
Conversion electron |
|
1.27502e-01 |
2.258e-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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