An Electro-Optical Pre-Amplifier Photomultiplier Combination with Integrated Power Supply Offering Excellent Single Electron Resolution for DUMAND

A large area electro-optical pre-amplifier photomultiplier combination for the DUMAND array is proposed with excellent single and multi-electron resolution compared with conventional photomultipliers. Photo-electrons from a hemispherical photocathode are accelerated to and collected on a fast phosphor screen, behind which a conventional photomultiplier is placed. The combination works as a photomultiplier with a very high gain (~ 50) first dynode. The design will be described and data will be given on collection efficiency, gain, single electron resolution, background, transit time and afterpulses. These properties will be discussed in view of the requirements for the DUMAND array and other applications.