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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

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

 

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.