Cryogenic uses various cryocoolers with cooling powers to suit different cryogen free magnet systems and applications. The Gifford-McMahon cycle cryocooler has the advantage of greater thermodynamic efficiency. The pulse-tube cryocooler is vibrationally quieter, has a longer service interval and cools faster from room temperature.
Key differences between Gifford-McMahon (GM) and Pulse Tube (PT) Cryocoolers
- GM cryocoolers are usually less expensive that a PT cryocooler with equivalent cooling power
- PT cryocoolers must operate almost vertical with the 2nd stage below the motor. GM cryocoolers can operate in any orientation.
- PT cryocoolers are generally a better choice where vibration sensitive measurements are required.
- PT cryocooler maintenance intervals are longer than GM cryocoolers but on site maintenance may be more difficult.