Cryocooler based helium liquefier development-A practical usage

A helium liquefier using a 1.5 watt at 4.2KGifford Mac Mohan (GM) cryocooler was developed at IUAC having a liquefaction capacity of 17.4 litres per day (lpd) at STP. This standalone setup could not be used for any other experimental facility which requires liquid helium for its functioning and so another portable experimental liquefier was designed and fabricated using the same technology, which can be used to hook up very easily using its liquid inlet line port. In the present experimental demonstration setup the cryocooler liquefier was hooked up to a commercial 100 l helium Dewar. The Dewar was cooled starting from room temperature with the cryocooler liquefier in 2 days and 50 litresof liquid helium was collected inside the Dewar. The measured production rate of liquefaction was 14.2 litres per day. Successful liquefaction of helium in such a portable setup opens up the door for using this technology for other experimental purpose requiring liquid helium.