ABSTRACT
Almost from the initial development of liquid-scintillation counting it has been known that liquid scintillators could be used for the detection of alpha emitters. The most recent, and certainly among the most important, developments in alpha spectrometry by liquid scintillation have been the introduction of methods of solving the problems of energy resolution, energy-scale calibration, rejection of beta/gamma-background counts, and methods of effectively separating alpha-produced pulses from beta- and gamma-produced pulses. The technology of separating alpha from beta/gamma pulses is variously referred to as Pulse-Shape Discrimination (PSD), Pulse Shape Analysis (PSA), Pulse-Decay Analysis (PDA), and beta/alpha discrimination. Such electronic circuits are now available in both the modified beta-liquid-scintillation spectrometers and in an alpha-liquid-scintillation spectrometer. The development of extractive scintillators, an aqueous-immiscible organic solution containing both the scintillator components and a liquid-liquid extraction reagent for transferring the nuclide-of-interest to the scintillator, has provided a method of accomplishing this and has made alpha-liquid scintillation possible in a practical way.
