Abstract :
Nuclear radiations impinging on a phosphor produce short flashes of fluorescence, or scintillations, which may be used to detect and measure the radiations. Major advances have recently been made in this technique, through the introduction of high-gain photo-multipliers to detect the scintillations. The various physical processes affecting the design of the nuclear scintillation counter are discussed, with particular reference to the most suitable phosphors and photo-multipliers. The advantages of the instrument over the conventional gas ionization counter are considered, and illustrated by reference to typical experimental applications in nuclear physics.