Berne Infinitesimal Bubble Chamber

The Berne Infinitesimal Bubble Chamber, BIBC, was almost pocket size, 6.5 centimetres across and with a visible volume containing about a wine glass of heavy liquid.

Charged particles create an ionization track, around which the liquid vaporizes, forming microscopic bubbles.

In fact the track of a charmed particle could be lost amongst the 'large' (half a millimetre) bubbles of large chambers.

The bubbles in the minichamber were about ten times smaller, and stood a better chance of picking up short tracks.

[1] BIBC was used at the CERN SPS in the experiment NA18 as vertex detector together with a downstream 2 m streamer chamber of the MPI-Munich which allowed for momentum analysis of the charged particles.