Big European Bubble Chamber

The Big European Bubble Chamber (BEBC) is a large detector formerly used to study particle physics at CERN.

The piston expansion, synchronized with the charged particle beam crossing the chamber volume, caused a rapid pressure drop; in consequence the liquid reached its boiling point.

[2][3] During each expansion, charged particles ionized the atoms of the liquid as they passed through it and the energy deposited by them initiated boiling along their path, leaving trails of tiny bubbles.

[8] Hydrogen-filled chambers enable the study of particle interactions with free protons but they have a low efficiency for gamma ray conversion.

[10] Furthermore, an Internal Picket Fence (IPF) was used to obtain timing signals for events occurring in the bubble chamber, helping to suppress the background.