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Related to proportional counter: ionization chamber, Scintillation detector, Townsend avalanche, Ionisation chamber
(General Physics) an instrument for detecting and measuring the intensity of ionizing radiation. It is similar to a Geiger counter but operates at a lower potential difference such that the magnitude of the discharge is directly proportional to the number of gas molecules ionized by the detected particle. This may permit the identification of the particle or the determination of its energy