Ion Counter

(also ionization counter), a device that detects the appearance or presence in a defined space, referred to as the sensitive volume, of an atomic or molecular ion. Ion counters are widely used in physics, especially in the study of the flow of charged or neutral particles. The principles of operation and construction of various types of ion counters are extremely diverse, and the choice of a counter in a particular case is determined by the characteristics, mainly the energy, of the ions being counted.