Cs137 Geiger Counter/Gamma Ray Spectrometry

Cs137 spetrum

Cs137 has characteristic spectrum at 661keV.

Cs137 spectrum
Idaho National Laboratory

Cs137 spectrum with iMetry

Linear Logarithmic
Cs137_liner.PNG Cs137_log.PNG

iMetry's basic spectrometry feature has lower resolution compared to professional equipments, so spectrum peak (661keV in Cs137) appears duller and wider, still characteristic peak around 661keV can be observed.
In area lower than 661keV, there is a trapezoidal raise caused by backscatter, be careful not to mistake this backscatter raise to other radiation spectra. *1
Also keep in mind that output from iMetry main unit may drift due to temperature, humidity, or aging, and there possibly be some shift of spectrum channels from simplified calibration performed prior to shipping.

Simplified calibration prior to shipping is performed with 137Cs, so if you want to add calibration points, using widely available Low sodium salt such as Yasashio measurement results may be a good idea.

  • *1 Compton scattering is a phenomenon that gamma ray photons lose energy and scatter wider in lower frequencies when they hit electrons. In scintillation detectors, dull trapezoidal raise can be observed in lower frequency area of the spectrum.


  • 最終更新:2013-06-16 22:20:23