Gargamelle, the heavy-liquid bubble chamber at CERN in which neutral currents were discovered

The CERN 2m hydrogen bubble chamber

How works

The bubble chamber, invented by Donald Glaser in 1952, consists of a tank of unstable (superheated) transparent liquid – for example, hydrogen or a mixture of neon and hydrogen at a temperature of about 30K. This liquid is very sensitive to the passage of charged particles, which initiate boiling as a result of the energy they deposit by ionizing the atoms as they force their way through the liquid.

Briefly, the bubble chamber works as follows:

The time between bursts varied from about a second in some chambers to about a minute in others; so an experiment needing hundreds of thousands of interactions could take many months.

 

More on the BC history >