A Helium Recondenser Using 4 K Pulse Tube Cryocooler

A helium recondenser using a 4 K pulse tube cryocooler (model PT405) has been developed as a solution to reduce liquid helium boil‐off in the existing non‐refrigerated helium dewar or helium cryostat. The condensing part of recondenser is inserted into the neck tube of the helium dewar or cryostat. The helium vapor is condensed at 4.2 K and the condensed liquid flows back to the liquid helium bath. The recondenser has been experimentally tested to condense 14 liters/day of liquid helium while consuming 4.5 kW electrical power.