Liquid scintillation counting of nickel-63

Abstract

Liquid scintillation systems based on gels, ether, and toluene are investigated for counting nickel-63. A nickel complex of n-caproic acid dissolved in a solution of toluene containing 1,4-bis(2-(5-phenloxazolyl)- benzene(POPOP) and 2,5-diphenyloxazole (PPO) is found to be prefterable with respect to reproducibility, ease of preparation, and interpretation. The addition of a small quantity of ethyl alcohol produces a slight loss of efficiency but stabilizes the solution in the presence of residual water. The method for preparing the sample is described. The results show that count rate increases with decreasing temperature. (N.W.R.)