Thermal shunt for quick cool-down of two-stage closed-cycle refrigerator

✍ Scribed by Kurt Uhlig

• Book ID: 104112229
• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 129 KB
• Volume: 42
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/s0011-2275(01)00177-1

✦ Synopsis

An efficient and easy-to-build gas circuit is described which acts as a thermal shunt between the two stages of a Gifford-McMahon cooler (GMC) during the cool-down period of an experiment. With this circuit the high cooling power of the first stage is used to cool objects with a large heat capacity attached to the second stage like a superconducting magnet or, as in our case, a dilution refrigerator (DR) with a vacuum can. The circuit is driven by a small fraction of the helium gas of the Gifford-McMahon refrigerator and precools the DR from room temperature to a temperature of 50 K. The shunt circuit reduces the cool-down time by a factor of two in our cryostat.