Transient Heat Conduction in Cryogenic Current Cables Following a Loss-of-Coolant Accident

The current supply cables of large superconducting magnet systems are cooled with an axial stream of cold helium vapor. If the flow of coolant is suddenly interrupted the current cables may overheat and burn up causing extensive damage to the entire system. The transient temperature distribution in the cable after the loss-of-coolant accident is derived analytically. The paper presents the maximum cable temperature versus time for a cryogenic current cable which stretches from room temperature (300 K) to a liquid helium-cooled superconducting system (4.2 K).