Design, Construction and Operation of the 50 Centimeter Liquid Helium Bubble Chamber

摘要

The chamber, whose dimensions are 50 x 25 x 30 cu cm, is operated in the magnetic field whose maximum value is approximately 28 kilogauss. The photography is of the dark-field type using straight-thru illumination from a diffusing screen with dark patches. A pair of condensers, located close to the chamber, form images of the dark patches about the 3 camera lenses, which view the chamber with 16 degree stereo. New cameras have been installed which use 35 mm sprocketed film, and these cameras can advance in 0.1 seconds. The chamber has completed a successful run producing 400,000 triads in a 150 MeV/c pion beam at the University of Chicago synchrocyclotron. It requires a crew of three and can be lifted into the beam in an operational condition. The static loss rates from the liquid helium reservoir are around 2 liters/hour and the dynamic loss is about 1 liter per 400 expansions. (Author)