Safeguards Analytical Laboratory
Alpha/Beta Proportional Counter for Screening Environmental Samples
The gas-flow proportional counting system shown below is used to screen environmental swipe samples for the presence of alpha or beta-emitting isotopes. Each sample is removed from its plastic bags and placed in a cassette for introduction into the counting chamber using a 50-position sample changer syetem. The chamber is filled with counting gas and data are collected for 1 hour. The final result is the total number of alpha and beta counts, corrected for background, This system has high collection efficiency and has sensitivity in the mBq range. Alpha emitting nuclides such as 210Po and beta-emitters such as 3H, 90Sr and 99mTc can be measured in this way much more sensitively than by gamma or X-ray methods.
Alpha/Beta Counter