Radioactivity measurement of 3H-labeled gas with position-sensitive proportional counter

A position-sensitive proportional counter with a partially resistive anode wire was constructed for activity measurement of 3H-labeled methane and its characteristics were measured. The new method was able to completely eliminate the influence of the end effect of the counter and the effective volume of the counter was accurately measured with estimated uncertainty of +- 0.12%. The activity per unit volume 3H-labeled methane in the counter was determined with a tentatively estimated uncertainty of +-0.79% (at a level of one standard deviation). (author)