Skip to Main Content
In superconducting magnets operating at high heat loads as the ones for interaction region of particle colliders or for fast cycling synchrotrons, the limited heat transfer capability of state-of-the-art electrical insulation may constitute a heavy limitation to performance. In the LHC main magnets, Nb-Ti epoxy-free insulation, composed of polyimide tapes, has proved to be permeable to superfluid helium, however the heat flux is rather limited. After a review of the standard insulation scheme for Nb-Ti and of the associated heat transfer mechanisms, we show the existence of a large margin available to improve insulation permeability. We propose a possible way to profit of such a margin in order to increase significantly the maximum heat flux drainable from an all polyimide insulated Nb-Ti coil, as it is used in modern accelerator magnets.
Date of Publication: June 2008