Wire chambers are based on the idea that charged particles can be registered when they traverse through a gas. The particles will collide with the atoms in the gas and knock out electrons from the atoms. This is called ionisation since the atoms become ions. An electrical potential makes the electrons move to the anode and the ions to the cathode. The electrons will then be registered as an electrical current.
A multi wire proportional chamber (MWPC), one type of track detectors used in modern particle experiments, has several anode wires attached between two cathode planes. The distance between the anode wires is about 2 mm and the distance between the cathode planes is about 2 cm. The particles way through the chamber can be calculated using the positions of the anode wires. Several chambers are positioned at a distance from each other to register tracks of the charged particles.
The drift chamber is a further development of the MWPC. The drift chamber uses the fact that it takes some time for the liberated electrons to travel to the anode. By measuring this time very accurately the position of the original particle can be determined with great precision. This technique has been used in for example the Time Projection Chamber (TPC) in the DELPHI detector.