31. "' SWEEPNIK "'was a device designed by Otto Frisch that used a sweeping laser to follow bubble chamber tracks. 32. Cloud chambers work on the same principles as bubble chambers , but are based on supersaturated vapor rather than superheated liquid. 33. Before he retired he designed a device, SWEEPNIK, that used a laser and computer to measure tracks in bubble chambers . 34. In 1957 McCormick accepted a post as staff physicist at the Alvarez Hydrogen Bubble Chamber Group at the Lawrence Berkeley Laboratory. 35. In 1968 he joined the BEBC project and worked on bubble chamber physics until 1984 when the project was eventually terminated. 36. The bubble chamber was filled with 1150 litres of liquid hydrogen and was expanded by a piston placed at the top. 37. While bubble chambers were extensively used in the past, they have now mostly been supplanted by wire chambers and spark chambers. 38. The muons can be easily detected by many types of particle detectors, such as cloud chambers, bubble chambers or scintillation detectors. 39. The huge Gargamelle bubble chamber photographed the tracks of a few electrons suddenly starting to move, seemingly of their own accord. 40. The bubble chamber similarly reveals the tracks of subatomic particles, but as trails of bubbles in a superheated liquid, usually liquid hydrogen.
