4/pi/ scintillation equipment for measuring low beta-activities

A low background equipment for 4(pi)-measurements of beta-active samples with a carrier is described. The special construction of the scintillation detectors and the original electronic circuit made possible the achievement of a limit of detection of 0.33 pCi with time of measurement 60 min and a confidence interval 95% for a sample of yttrium-90 after standard radiochemical treatment. The scintillation detectors and the electronic circuit fulfill all requirements for assuring effective protection from cosmic rays. The qualitative indices of this equipment exceed those of known equipment using scintillation technique. The results obtained do not exhaust the possibilities of the proposed measurement technique.