Leak Rate of Helium Gas through a Clearance at Low Temperature

Abstract

Leak rate of helium was measumed in labyrinthine clearance 11 or 13μ of an Collinstype expansion engine in 36mm diameter, under the pressure difference of 20kg/cm². Temperature coefficient of leak rate by theoretical calculation was in good coincidence with the observed value. Therefore the affect of the leak rate to refrigeration capacity of engine can be evaluated at 20-280°K. A comment on Doll's report is also presented.
Leak rate of helium at a valve sheet made of leather or TEFLON was measured at 30-280°K under the pressure difference of 15kg/cm² and a theoretical equation was derived.