RADIONUCLIDE
DATA SHEET
CESIUM 137
Chemical Symbol:
Cs-137
Half-Life:
30.08 years
Atomic Number:
55
Decay Constant:
0.023043 years-1
Mass Number:
137 (82 neutrons)
Decay Mode:
Beta
U.S. NRC Exempt Quantity Limit:
10 μCi (370 kBq)
IAEA Exempt Quantity Limit:
0.27 μCi (10 kBq)
Gammas From Cs-137
Energy (keV)
Intensity (%)
283.53
0.00058
661.657
85.1
X-rays From Cs-137
Energy (keV)
Intensity (%)
Assignment
3.954
0.0143
Ba Ll
4.331
0.0064
Ba Lh
4.451
0.040
Ba Lα2
4.466
0.36
Ba Lα1
4.827
0.226
Ba Lβ1
4.852
0.023
Ba Lβ4
4.927
0.039
Ba Lβ3
4.994
0.0030
Ba Lβ6
5.156
0.074
Ba Lβ2
5.531
0.033
Ba Lγ1
5.797
0.0065
Ba Lγ2
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5.809
0.0093
Ba Lγ3
31.452
0.000263
Ba Kα3
31.817
2.04
Ba Kα2
32.194
3.76
Ba Kα1
36.304
0.352
Ba Kβ3
36.378
0.680
Ba Kβ1
36.652
0.0079
Ba Kβ5
37.255
0.215
Ba Kβ2
37.349
0.0481
Ba Kβ4
Betas From Cs-137
End-Point Energy (keV)
Intensity (%)
513.97
94.4
892.22
0.00058
1175.63
5.6
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Cs-137 Decay Scheme
Reference(s):
- Health Physics and Radiological Health, 4th Edition by Thomas E. Johnson PhD, Brian K. Birky Ph.D.
- National Nuclear Data Center database - http://www.nndc.bnl.gov/
- Table of Radioactive Isotopes (ToRI) database - http:/nucleardata.nuclear.lu.se/nucleardata/toi/
Prepared by:
Spectrum Techniques, LLC.
106 Union Valley Road
Oak Ridge, TN 37830
Phone: 865.482.9937
Fax: 865.483.0473
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Website: www.spectrumtechniques.com
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