COMPARISON OF DIFFERENT WAYS OF USING SUPERFLUID-HELIUM TO COOL SUPERCONDUCTING MAGNETS

Several different schemes have been used or proposed for cooling large magnets using superfluid helium. These systems operate in three diffe rent heat transport regimes, depending on whether internal convection, forced convection, or both carry significant amounts of heat. A schem e is proposed for classifying global heat transport systems into four classes, and their essential thermodynamic characteristics are compare d. Geometry is shown to have a large impact on temperature rise and co oling system performance. Some specific examples are shown for local h eat transport between laminations of an accelerator magnet, and for gl obal transport of the magnet heat load to the external refrigeration s ystem.