Bubble bath

Foam filling the empty CMS cavern
Spectacular test of the fire extinguishing system in the underground cavern of the CMS experiment in 2006 (Image: Maximilien Brice/CERN)

12 May 2006, CMS cavern. The CMS cavern is transformed into a winter wonderland as foam comes shooting out of the twelve foam blowers lining the upper cavern walls on both sides. In less than two minutes 7m3 of water mixes with a small percentage of foaming liquid, transforming into 5600m3 of foam. More images.