Investigations in alpha liquid scintillation spectrometry

A recently developed technique known as Photon/Electron-Rejecting Alpha Liquid Scintillation (PERALS) Spectrometry has made liquid scintillation a useful alternative to conventional alpha spectrometry techniques. The advantages of the PERALS method include ease of sample preparation and essentially 100% counting efficiency. The primary disadvantage Is the relatively poor energy resolution as compared to solid state techniques. A significant improvement in resolution would likely make this technique superior to any other alpha counting technique available at this time. Various modifications in the current PERALS scintillator solutions were investigated in an effort to detect any promising means for resolution improvement. Studies included the use of a number of different primary solvents, the effect of naphthalene concentration on resolution, and the use of liquid naphthalene derivatives as both primary and secondary solvent. Additional experiments Included the effect of an adducting agent and a drying agent on a typical PERALS scintillator solution, and the Influence of counting temperature on energy resolution. Some solutions were prepared which appeared to yield greater light output, but no significant improvement in energy resolution was observed. Several solutions were found to be useful alternatives to PERALS scintillators.