THE DEVELOPMENT OF AN ALPHA-BETA SEPARATION LIQUID SCINTILLATION COCKTAIL FOR AQUEOUS SAMPLES

Scintillation cocktail components were studied with regard to their im pact on pulse decay discimination (PDD) and hence the separation of al pha from beta activity. using a Packard 2250 CA alpha/beta. Di-isoprop yl naphthalene (DIN) was found to be the most suitable solvent, both f rom safety considerations and also the fact that it acts in a very sim ilar manner to naphthalene in stretching the pulses produced at the ph otomultiplier tube anode and hence enhancing the separation. Increasin g the surfactant concentration and the use of dimethylanthracene (DMA) as secondary fluor degraded the cocktail's performance. PMT anode pul se shapes were found to be a useful indicator of PDD efficiency but co uld not give a quantitative guide.