1985 Volume 71 Issue 2 Pages 236-241
A Fatigue Testing Machine at Liquid Helium Temperature with new re-condensing type cooling system was installed in National Research Institute for Metals, Tsukuba Laboratories. The machine has been designed for long-term fatigue testing at liquid helium temperature. The machine has a recondenser in the closed test machine cryostat. Helium mist is transferred to the recondenser from the refrigerator and evaporated helium gas is recondensed in the cryostat. The liquid helium level in the cryostat is kept constant without additional supply of liquid helium during the testing. This recondensing type cooling system has achieved long-term continuous operation for more than 460 h.