Self-driven HeII cooling system for the interaction region focusing magnets at SSC

The focusing magnets nearest the interaction points of the Superconducting Super Collider (SSC) face concentrated and somewhat unpredictable heat loads from the radiation produced by the proton beam collision. A three-stage cooling system design is shown that interfaces with the SSC external refrigeration system and minimizes hot spots in the magnet. The magnet cold mass can be held below 2 K even with a heat load of 1 kW. Internal convection with zero mass flow between the magnet laminations carries the heat radially outward from the center of the magnets to large coolant passages near the periphery. Cross flow is not required. A circulation system driven by the heat being removed then carries the heat axially through the 60 m long set of magnets. A heat exchanger/thermomechanical pump module transfers the heat to the external refrigeration loop, permitting the external loop to be optimized without matching the flow rate required through the magnets. These results are useful beyond the SSC community as examples of using He II to transfer large amounts of heat in industrial-scale superconducting magnets