Straw chamber

A straw chamber is a type of Gaseous ionization detector. It is a long tube with a wire down the center and a gas which becomes ionized when a particle passes through. A potential difference is maintained between the wire and the walls of the tube, so that once the gas is ionized electrons move in one direction and ions in the other. This produces a current which indicates that a particle has passed through the chamber.

Many straws together can be used to track particles in a straw tracker.