A METHOD OF CONCENTRATING He3–He4 MIXTURES

Abstract

We have developed a method of increasing the concentration of He³ in He³–He⁴ mixtures by "superfluid filtration", relying upon the fact that liquid He⁴ flows rapidly through a small leak while the He³ in solution remains behind. In this way an increase in concentration from 2% to 95% can be achieved in a single operation. The rate of processing is about 200 standard cc. of the initial gaseous mixture per hour.