Forced flow He II cooling for superconducting magnets - design considerations

A review of the engineering considerations for the application of forced flow He II is presented. Issues discussed include: steady state and transient heat transfer up to the highly transient thermal shock regime; pressure drop and circulation methods. The survey of the He II heat transfer processes shows some advantage to forced flow cooling, particularly for long hydraulic cooling paths. On the other hand, the hydraulic behavior of the He II flow is best correlated with classical models for incompressible fluids. Pressure head must be provided by circulation pumps, which add heat and complexity to the system. The above review is presented in the context of a closed He II cooling loop for a forced flow CICC magnet. (C) 1998 Elsevier Science Ltd. All rights reserved.