Abstract

We describe a passive heat switch based on a commercial pyrolytic graphite sheet. Measurements of the thermal conductivity of the graphite are presented, confirming a large difference between room temperature and ≈4 K. The implementation of a graphite heat switch in a cryostat operating a 3He/4He sorption refrigerator is demonstrated.

Achievements

  • Improved the cooldown time for the 3He stage by 50% with inexpensive graphite sheet
  • Demonstrated the ‘off’ state of the switch applied only microwatts of heat load
  • Proved durability through 10+ room temperature-cryogenic cycles
  • Able to reduce the number of expensive gas-gap heat switches needed to conduct experiment

This publication is based on research conducted in PXS Cryogenics.

Back to Publications