PARAMETRIC ANALYSIS OF FORCES AND STRESS IN SUPERCONDUCTING MAGNETS

by Federico Regis (CERN)

Tuesday 5 May 2009, 14:00 → 15:00 Europe/Zurich

30/7-012 (CERN)

In superconducting magnets, electromagnetic forces and associated stresses are generated by the interaction of the cable current with the magnetic field. Two main issues have to be analyzed at the design stage: first, a mechanical structure must be envisaged to contain these forces and to limit the cable movements during the magnet ramp; secondly, the stresses inside the coil must not exceed the limits beyond which insulation can start creeping and the superconductor properties are degraded. This last aspect is critical for the Nb3Sn which, according to measurements carried out on cables, cannot tolerate compressive stresses larger than 200-150 MPa. In this work we aim at analyzing how forces and stresses depend on magnet aperture, on the coil width, and on the superconducting material. We used a simplified coil layout made up of a sector of inner radius ri, radial width w and angular extension α0 as a representative of cosθ-type magnets, namely quadrupoles and dipoles. A parametric analysis has been carried out, considering both coils in air and enclosed by an iron yoke. A comparison with some state of the art magnets is finally presented.

Slides Regis_ScalingLaws.pdf.pdf