Basics of Geiger-Muller counter

What is a Geiger-muller counter?

Geiger-muller counter is a mostly used ionisation radiation detector. Geiger-muller counter detects nuclear radiations such as alpha particles, Gamma particles, Beta particles. using ionisation effect produced in the Geiger-muller tube. And it has an operating voltage of 800-2000 volts.

Working of Geiger-muller counter:

A Geiger-muller counter consists of a Gieger-muller tube with a window at one end. The tube is filled with inert gases such as Helium, Argon. A high voltage is passed across the tube wall and the central electrode wire. The circuit will be opened and there will be no current passing through the circuit.

When ionisation radiation enters the tube, it will initiate the avalanche of electrons and ions in the tube. The collection of charge produced in the tube makes the tube conductive.

A voltage pulse is formed as the output of the circuit. The amplitude of the voltage pulse is proportional to the radiation count of the incident radiation. The voltage pulse signal is processed and then use to operate a scaler circuit. The scaler circuit produces the actual count of the radiated energy.


  • Particle detection

  • Gamma, neutron detection

  • X-ray radiation

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