Evaluation of Whole Body Counter at Nagasaki University

A whole body counter was installed at Nagasaki University in 1968. Evaluation of the whole body counter was done by accumulated data during 15 years since its installation. The items used for the evaluation were the background radiation, the resolution and sensitivity of the measurement system. The characteristics of the apparatus has been stable for these years: The background counting rate was 1400 cpm, the relative resolution for 1.4 MeV gamma-rays was 8.5 %, and the sensitivity for 1 kg of potassium chloride (KC1) was 2150 cpm. The number of experimental and clinical measurements for patients was about 350 every year. The most frequent measurements were of K-40 and Cs-137; 74 %. The repeated measurements of potassium concentration for healthy subjects were performed during a long period, and were analyzed