A New Liquid Helium Temperature Fatigue Testing System

A liquid helium temperature fatigue testing system was developed at the National Research Institate for Metals, Tsukuba Laboratories. The system is equipped with a recondenser intalled in the test machine cryostat, whereby the helium mist is transferred to the recondenser from the refrigerator and the evaporated helium gas is recondensed in the cryostat. Thus, the liquid helium level in the cryostat is kept constant without an additions supply of liquid helium during testing. A continuous operation of more than 460h has been achieved with this fatigue testing system.