Multi-needle detector with cathode focusing

Abstract A new type of multi-needle counter is described. Some main characteristics observed on prototypes are recalled. Its high multiplication factor associated with a photosensitive gas mixture made this detector a photon counter. The detection of a Cherenkov ring image produced by a single proton is related and demonstrates the ability of a multi-needle counter to solve imaging problems for simultaneous events. Development of a modular construction is suggested for large area detectors.