A photomultiplier tube incorporating an avalanche photodiode

Abstract A photomultiplier tube incorporating an avalanche photodiode operated in the electron bombardment mode has been developed and tested. It has a large linear dynamic range, can operate with gains up to 10 6 , is unaffected by axial magnetic fields and has been measured to have excellent timing properties. Different versions of the tube were made with bialkali, multi-alkali, and negative electron affinity photocathodes, in this paper we will report on results obtained with these different types of photocathodes. This type of PMT will be useful for applications where large dynamic range and high quantum efficiencies are required. The extension of this concept to a multichannel device with a segmented APD array will provide an economical readout for both fiber tracking and calorimetry applications. A tube equipped with such an array is being developed currently as a readout option for the SDC shower maximum detector.