Spark-chamber detector

A spark-chamber detector is a particle detector, a device used in particle physics for detecting electrically charged particles. It was most widely-used in the 1970s, and has since been superseded by more sophisticated detectors such as drift chambers and silicon detectors. Spark chambers are still of scientific value due to their relative simplicity.

Spark-chamber detectors consists of metal plates placed in a sealed box filled with a gas such as helium, neon or a mixture of the two. As a charged particle travels through the detector, it will ionize the gas between the plates. A trigger system is used to apply high voltage to the plates to create an electric field immediately after the particle goes through the chamber, producing sparks on its exact trajectory.

Spark-chamber detectors are generally less accurate than bubble-chamber detectors, but can be made highly selective with the help of auxiliary detectors, making them useful in searching for very rare events.