Energy Doubler refrigeration system

The Energy Doubler refrigeration system is required to cool long strings of warm iron magnets with a high degree of reliability and/or redundancy. The 6.5 km circumference together with the extremely small cooling channels dictated by the warm iron configuration necessitates the usage of subcooled liquid in the coil chambers. The largest component of heat load is the ac losses in the coils followed by two equal components: lead cooling and thermal heat leak. This gives an important additional degree of freedom; i.e., to reduce the ramp rate while repairs are in progress. Only a magnet failure or loss of vacuum in the satellite cold box will shutdown the system for an extended period (two days). With the system operating in a nonfailure mode recovery time for a single magnet quench is three minutes. The design concept of the central liquefier supplying satellite stations as well as failure modes are discussed. Performance data are presented