Sand gravel Thorium Geiger Counter/Spectrometry

RX-228:Natural sand gravel radium radiation source contains Thorium

This is a radiation source for educational purpose.
RX-228, consists of radioactive powder contains thorium solidified with binder and stored in PVC holder, and emits only gamma rays.
With 1.0mm thick Fe window and more powder amount, achieves higher gammma ray count rate.

Geiger counter measurement with iMetry

In an environment with 0.05μSv/h background, iMetry showed 0.7114μSv/h when placed as shown in the picture. With higher cpms, iMetry's extraordinary stability distinguishes even more.
Completely flat...

Gamma Ray Spectrometry with iMetry

A few peaks are observed, let's compare from high-energy side with reference spectrum obtained be Kromek GR-1.
  • 2594keV is out of range
  • The hill on slight right from the center corresponds to 1583keV.
  • Raise on slight left from the center is considered to be combined peak of 908keV and 962keV.
  • Around the yellow line might be 585keV. Lower than that might be mis-calibrated.
  • Small unevenness seen on the left of the yellow line might be 336keV.
  • The very left small peak might be 239keV.

(Reference) Spectrum obtained with Kromek GR-1


(Reference) Th232 spectrum peaks(Idaho National Laboratory


  • 最終更新:2013-10-09 19:34:31