FRIB cryogenic plant makes first liquid helium

The FRIB cryogenic plant made its first liquid helium at 4.5 kelvin (K) on 16 November 2017.

Making cold helium is critical to operating FRIB’s linear accelerator. FRIB’s beam-accelerating cryomodules contain superconducting radio frequency cavities that must operate at temperatures hundreds of degrees below zero to be superconducting. The cold helium will make the cavities superconducting.

FRIB’s two cryogenic cold boxes (the upper and lower cold boxes) work in tandem to cool helium to extremely low temperatures. The upper cold box lowers the temperature from 300 degrees K to 60 K. The lower cold box serves as the second step in the helium-cooling process, dropping the temperature from 60 K to 4.5 K.