Spark chamber - Definition and Overview

A spark-chamber detector is a particle detector, that is, 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 It was most widely-used in the 1970s, and has since been superseded by more sophisticated detectors such as drift chambers and silicon detectors; however, spark chambers are still of scientific value due to their relative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 gas (for example, helium, neon or a mixture of the two); as a particle travels through the detector, it will ionize the gas between the plates, and a trigger system is used to apply high voltage to the plates to create an electric field immediately after the particle went through the chamber, producing sparks on its exact trajectory.

Spark-chamber detectors are generally less accurate than bubble-chamber detectors; however, they can be made highly selective with the help of auxiliary detectors, thus proving useful in searching for very rare events.