Energy dump concept for large energy storage coils. [Energy dump concept]

A scheme to internally dump all the energy stored in a large superconducting energy storage coil in an emergency situation is described. The magnet is a 1000 MWh single layer solenoid cooled by superfluid helium. The dump concept involves dumping the helium into a cooled reservoir, shorting all the turns and the cold structure, and triggering the first few top turns normal by means of an attached heater. This concept insures a uniform final temperature in the winding and the structure. The voltage distribution across the coil during the dump time is also discussed.