Heat transfer in electrical insulation of LHC cables cooled with superfluid helium

摘要

The electrical insulation of the Large HadronCollider (LHC) cables constitutes a thermal barrier between theconductor and the superfluid helium bath. This can preventremoval of the heat dissipated in the cable by the current rise in thedipoles or by the beam losses. The main experimental results,obtained with stacks of insulated conductors representing a pieceof the actual coil, are given. The mock-ups vary only by thematerial composition and the structure of the electrical insulation.Analysis of the temperature distribution measured in theconductors as a function of the dissipated heat power makes itpossible to determine the dominant heat transfer mode in each typeof tested insulation and to classify these according to theirpermeability to superfluid helium. Thermal numerical modellingvalues of the thermal quantities characteristic of each insulation.The results of these studies have led to the choice of the cableinsulation of the LHC magnets. 2000 Elsevier Science Ltd. All rights reserved.