Charpak spark chambers, with Mr Bouclier The great advance in the technology of particle detectors during the year was the discovery of the properties of multiwire proportional chambers and drift chambers

In these chambers each wire is an independent proportional counter with its own amplifier and logic circuit. The low cost of the associated electronics makes realistic moderately large systems, with thousands of wires. The resolution time of each wire is of the order of 100 ns, with 3mm spacing. Roger Bouclier is working on an early model tested in a PS beam-line.