ABSTRACT
The principal application nowadays for charge multiplying gas-filled detectors is for use as large area position sensitive detectors. The charge multiplication processes which occur in gases come from the movement of the free electrons rather than the positive ions. The presence of a quenching gas can give an enormous increase in the gain obtainable together with stable detector operation. The presence of this gas will, of course, cause the electrons in the avalanche region to lose some of their energy without producing ionization and the voltage needed to give a particular gain will be higher than for pure argon. Gas-filled counters detect the ionization left behind when a fast charged particle passes through the gas. In the early days of particle detection the gas-filled counter was much used as a simple detector, as exemplified by the Geiger–Muller counter.
