The Geiger-Muller tube - radiation detector (video)

Published: May 04, 2024

Tags:

GM Tube
Geiger Muller tube
gas filled detector
GM Counter
radiation detector
Alpha radiation
beta radiation
Gamma radiation
neutron radiation
boron
inert gas
argon
neon
radiation window
thin mica
potential difference
Anode
Cathode
end cap energy filter
ambient count
ambient dose
gas amplification
electric field
avalanche effect
dead time
recovery time
recombination
quenching
Dose Rate
counts per second
CPS
Contamination
pulsed radiation

Source: Ionactive Radiation Protection Resource

An animated video explaining how the Geiger-Muller tube functions - a classic radiation detector which was envisaged in 1908, practically built in 1928, and is still a widely used detector today in 2024 (nearly 100 years later!).

Notes on this video

The Geiger-Muller (GM Tube) is essentially a cylindrical diode filled with a low pressure gas. The central electrode is held at a moderately high voltage. The gas filling is at lower than atmospheric pressure and is adjusted in manufacture so that its initial ionisation by an incident particle or photon, causes subsequent electron - ion pairs to be produced as a result of an accelerating field between the central wire and the cylinder wall.

GM tube based monitors are:

Robust (but don’t drop one)
Easy to use
Relatively cheap
Easy to carry (being small and light)
Not ideal for measuring pulsed radiation
Liable to suffer from RF interference
Not applicable for all types of radiation

Further resource

You may want to consider some practical matters when using this type of equipment. Try this Ionactive resource: Use Counts per Second (CPS) to find it, and Dose Rate to define it.