Quench study and helium transport in tightly wound coils

In quench analyses of helium bath cooled superconducting magnets, the helium cooling is often treated as a cooling term that is generally a function of conductor temperatures. Such a method can encounter difficulties when dealing with a tightly wound coil where flow resistance is significant. In this case, helium acts not only as a coolant or thermal mass but also as a medium through which thermal energy is being transferred. The mass and energy transport of helium thus plays an important role in the normal zone propagation/expansion and the magnet overall quench performance. This paper discuss a quench study that incorporates the analysis of helium mass and energy transport with the overall quench thermal analysis. Experiments have verified this approach and showed that its prediction is in good agreement with test results.