Experimental helium liquefier using a GM cryocooler

by Dr Anup Kumar Choudhury (Inter University Accelerator Centre)

Wednesday 5 Mar 2025, 00:00 → 02:00 Europe/Rome

A. Rostagni meeting room

A helium liquefier with a production capacity of 17.4 L per day at standard temperature and pressure has been developed at IUAC, using a 1.5 W @4.2 K GM cryocooler to study the heat transfer dynamics between the cryocooler cold stages and flowing helium gas. To minimise the usage of helium gas, a thermosiphon loop connecting liquid helium zone to the room temperature helium inlet line has been added to the system. A heater is used to evaporate liquid helium in the thermosiphon collection bottle and re-circulate the evaporated helium gas from liquid to warm inlet gas. A large number of temperature sensors were used on the wall of the cryocooler and the liquefier to measure the thermal response of the system. Finite element analysis was carried out to understand the heat transfer process in this region and validated with thermal response. In this talk we present our studies on the liquefier, based on temperature response during the cool down time, system characterisation under various heat loads in the thermo-siphon region, and an FEA analysis of the heat transfer process in the 2nd stage regenerator zone.