ABSTRACT
So far, we have discussed signals from the collection of ionisation charge produced by an incoming charged particle. As long as the volume is large enough to provide a sufficient amount of charge, the detection elements in such detectors can be made small, leading to detectors that are capable of precisely locating the passage of charged particles. However, sometimes position resolution is not the primary target, but a large dense detector volume or cheap instrumentation of a large volume is required. In that case it is often easier to collect optical photons, which have a long range in transparent materials. Such photons can be generated in detector materials called ‘scintillators’ from the relaxation of excited states created by the electromagnetic interaction of the incoming charged particle with the detector.
