Bubbles can therefore form along the track of a charged particle, and make it visible. This was the principle exploited by Glaser in 1952 in the first bubble chamber , which proved of great importance in particle physics experiments for many years. When particles have passed, and possibly interacted in the chamber, the piston is moved to reduce the pressure, allowing bubbles to develop along particle tracks. After about 3 milliseconds have elapsed for bubbles to grow, the tracks are photographed using flash photography.
Several cameras provide stereo views of the tracks.
The piston is then moved back to recompress the liquid and collapse the bubbles before boiling can occur. Other liquids can also be used, to provide an alternative target. E.g. if deuterium is used, interactions with both protons and neutrons are possible. Heavier liquids are useful for detecting photons, but may not be appropriate as the primary target. Additional external detectors can be used to trigger the flash and film advance, to select particular types of events.