Comparison of helium II cooling systems for superconducting magnets using self-driven mass flow and zero-flow heat pipes.

This end-to-end numerical model is based on the well-established two-fluid physical model of helium II, and automatically takes into account the interactions between the different segments of a practical system. Four classes of helium II cooling system are identified which differ in the heat transport mechanisms used and in the means used to suppress boiling. Self-driven circulation loops, in which the heat removed drives helium II flow, are compared with zero-mass flow heat pipes for Astromag and for a large ground-based magnet system, and factors affecting the trade-off are discussed.