DUAL-CHANNEL PHOTOELECTRONIC MULTIPLIER Russian patent published in 1995 - IPC

FIELD: scintillation counters. SUBSTANCE: dual-channel photoelectronic multiplier has rectangular- or square-section glass bulb, photocathode, focusing electrode, diaphragm, first diode, two identical multiplying systems starting from second diode, and two anodes. Photocathode is built up of two similar parts spaced apart at gap with cylindrical surface common for two channels and following shape of inner surface of face glass of bulb. Axis of this surface crosses first diode common for two channels of photomultiplier. Focusing electrode is built up of three screens of which two are placed one inside other; internal T-section screen is located in symmetry plane of multiplier and external enclosed screen is of rectangular or square section corresponding to built section; it is arranged along bulb walls. Third screen is flat and placed in symmetry plane of multiplier abutting photocathode. Diaphragm separates cathode chamber from multiplying system. First diode is common for two channels and arranged along symmetry axis of multiplier. Light-absorbing layer may be applied to gap between two photocathode parts. EFFECT: order-of-magnitude reduction of optical feedback while maintaining desired focusing of photoelectrons. 2 cl, 3 dwg