Skip to Main Content

Gamma Counter

A gamma counter often is not portable. Gamma counters do just as the name implies—quantify the activity of a gamma-emitting sample. In principle, the gamma counter is like a scintillation detector with the exception that with a gamma counter the scintillation crystal surrounds the sample. The gamma rays interact with the crystal, are absorbed, and produce light. As with the scintillation detector survey meter, if the energy of the interacting photons is too low, the photons of light that are produced may be absorbed in the scintillation crystal and never be detected. If the energy is too high, the incoming photons may just pass right through without interacting. The thickness of the crystal is critical and the efficiency of the instrument for detecting certain gamma-ray energies is dependent upon the thickness of the crystal.