Single Photon Detection and Timing: Experiments and Techniques

Abstract

This chapter discusses the various aspects of single photon detection and timing. Single photon detection and timing means essentially the detection and timing of a single photoelectron released by light from a photosensitive surface of a photomultiplier, channel multiplier, avalanche multiplier photodiode, or other photo devices. An electron released by a particle or photon bombardment of a windowless multiplier is also included. Single photoelectron detection requires sufficient low-noise amplification to overcome the Johnson noise in the first resistor of the eventual electronic circuit plus additional amplification to operate standard discriminator detection circuits. Secondary electrons thus have a much greater escape depth and the multiplication at an electrode can be expected to be much larger than for the same primary energy incident on a conventional material. A number of multipliers with high gain, well-focused structures have an output pulse height distribution for single photoelectrons that is peaked with a fairly narrow width. The device noise in channel photomultipliers is also elaborated.