The bewildering variety of devices used as radiation detectors could easily give the impression that this is a difficult subject, but this is not so. Electromagnetic radiation can only interact with charged particles. At wavelengths longer than those of X-rays the energy of a single photon is so small that only the lightest charged particles (electrons) are significantly affected by the passage of an electromagnetic wave. Consequently all of the radiation detectors discussed below have one essential function: to transfer some or all of the energy in a photon or electromagnetic wave to an electron in a special environment that allows us to detect such an excited electron.

Comments are closed.