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Radionuclide Dosimetric Data Sheets

Cerium-137m

Summary data

General

Classification

Isotope:  Ce-137m
Atomic number (Z):  58
Mass number (A):  137
Neutron number (N):  79

Radioactive decay

Decay modes:  Electron capture, Internal transition
Half-life:  34.4 [h]
Decay constant:  5.5971e-06 [1/s]
Daughters:  Ce-137 (99.2%), La-137 (0.78%)
Radioactive daughters:  Ce-137, La-137

Dosimetric constants

Mean alpha energy:  0.0 [MeV]
Mean electron energy:  0.20674 [MeV]
Mean photon energy:  0.05578 [MeV]
Air kerma rate constant, Γ10:  3.682e-18 [Gy·m2/Bq·s]
Air kerma coefficient, Kair:  3.682e-18 [Gy·m2/Bq·s]
Equilibrium dose constant for weakly-penetrating radiations (α and/or electrons), Δwp:  3.312e-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-:  3.312e-14 [Gy·kg/Bq·s]
Equilibrium dose constant for photons, Δp:  8.937e-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/Ce-137m 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/Ce-137m 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/Ce-137m Summary Spectrum.csv

 

Energy [MeV]

Yield [#/nt] if > 0.01

Radiation type

1.61219e-05

1.033e+01

X-ray

2.10611e-05

1.570e-01

X-ray

4.82666e-03

4.092e-02

X-ray

5.25981e-03

2.348e-02

X-ray

3.42907e-02

1.593e-01

X-ray

3.47432e-02

2.918e-01

X-ray

3.91962e-02

2.836e-02

X-ray

3.92855e-02

5.495e-02

X-ray

4.02466e-02

1.175e-02

X-ray

2.54290e-01

1.104e-01

Gamma

1.18532e-05

2.753e-02

Auger electron

1.22653e-05

1.469e+00

Auger electron

3.21300e-05

1.203e-02

Auger electron

6.09515e-05

5.429e-02

Auger electron

6.25981e-05

1.590e+00

Auger electron

6.27244e-05

1.786e-02

Auger electron

7.40057e-05

3.474e+00

Auger electron

1.34808e-04

5.477e-01

Auger electron

3.95960e-04

1.230e-01

Auger electron

5.82078e-04

1.739e-02

Auger electron

6.27105e-04

1.267e+00

Auger electron

7.80170e-04

9.198e-02

Auger electron

3.85301e-03

4.872e-01

Auger electron

4.71017e-03

1.605e-01

Auger electron

5.60026e-03

1.297e-02

Auger electron

2.83189e-02

3.445e-02

Auger electron

3.33488e-02

1.623e-02

Auger electron

2.13834e-01

6.086e-01

Conversion electron

2.47777e-01

1.242e-01

Conversion electron

2.48125e-01

2.764e-02

Conversion electron

2.48577e-01

6.717e-02

Conversion electron

2.53120e-01

5.099e-02

Conversion electron

2.54290e-01

1.397e-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

 

 

 

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