Cold Helium Circulation Systems

Reliability with Cryomech Cryocoolers

The complete system is closed-cycle, and operates with the reliability of the GM Cryocoolers and a warranty of 10 000 hours. The Cold Helium Circulation System uses the AL600 GM Cryocooler.

CHCS for Magnet Pre-Cooling

Cold Helium Circulation Systems can be used for pre-cooling superconducting magnets from room temperature to ~40K.

No More LN2 Pre-Cooling

Designed to reduce liquid helium bath contamination with no need for liquid nitrogen pre-cooling.

Helium Circulation Flow Rate

The helium circulation flow rate is ~3.3 g/s at 2 bar absolute pressure.

With the closed-loop CHCS systems, the customer’s object is cooled by mounting it to a cold finger through which circulating, constant-pressure, cold helium flows to absorb the heat load. The cold helium is cryocooled by a Gifford-McMahon Cycle Cryocooler separated from the cold finger by the flexible Cold Helium Transfer Line, eliminating vibrations. The CHCS comes in two capacity sizes: the 120W CHCS120, and the 200W @ 80K CHCS200.

For customers experienced with open-cycle flow Cryostats, the CHCS is essentially a cryocooled open-flow Cryostat-type system. When the open end of the flowing cold cryogen has been closed off and re-pumped, re-cryocooled and re-circulated, no cryogens are needed.

Inside the vacuum chamber assembly, the cold head of the AL Series Cryocooler interfaces with the circulating cold helium. It is here that the heat load added to the cold finger is pumped out of the CHCS. The compressor package, the cold head, two flexible lines and motor cord make up the components of the Gifford-McMahon Cycle Cryocooler.

The open-loop MPC600 CHCS System can provide remote and distributed cooling to a cryostat via helium gas. Helium gas is cooled with a Gifford-McMahon Cryocooler and circulated with a cryogenic circulator or “Cryofan.” The system connects to the cryostat via two flexible Cold Helium Transfer Lines with bayonet fittings, allowing the heat exchanger to be designed and integrated into the cryostat based on the application requirements.

Based on our CHCS technology, the MPC600 is a mobile cooling system for pre-cooling low temperature superconducting magnets (such as MRI magnets) from room temperature to 30K using helium gas. All components are contained on a mobile dolly, and it only requires a high-pressure helium gas cylinder, power, and cooling water to operate.