Scintillation counter using Geiger tube.

Electronic counter using Geiger tube. A Geiger-Mueller tube for detecting atomic radiation is hooked to an old style electronic counter (using neon tubes to display number of counts). In principle, a Geiger-Mueller tube can be used to detect high energy photons such as ting ions by knocking electrons off gas molecules. The freed electrons are attracted to the positive wire, accelerated by the 1000 volts to a high enough velocity to knock electrons off other gas molecules. This 'avalanche' of electrons flowing to the central wire is a current pulse that can be amplified and counted by electronic circuitry. Operation: turn up the voltage slowly until the counter starts counting. Don't raise the high voltage more than 150 volts above where the counting begins. Don't exceed 1000 volts on the tube. Ref.:Modern College Physics by Harvey White, 3rd ed., p. 847-858