The Gargamelle, now on display at the CERN Microcosm museum science garden.
Gargamelle was a giant bubble chamber detector at CERN, designed mainly for the detection of neutrino interactions. Built in France, with a diameter of nearly 2 meters and 4.8 meters in length, Gargamelle held nearly 12 cubic meters of a freon (CF3Br). The usage of a heavy liquid, rather than the more typical liquid hydrogen, meant higher neutrino interaction probability, as well as easier identification of muons versus pions.
Gargamelle operated from 1970 to 1978 with a muon neutrino beam produced by the CERN Proton Synchrotron. These experiments led to one of the most important discoveries ever made at CERN: the experimental observation of the weak neutral currents was announced in July 1973, shortly after their theoretical prediction.
For the experiment, approximately 83,000 neutrino events were analysed, and 102 neutral current events observed. The signature of a neutral current event was an isolated vertex from which only hadrons were produced.