LHC Project Seminar: Persistent current effects in accelerator magnets - a review

by Bottura, L. (AT-MTM)

Thursday 19 Oct 2006, 14:15 → 15:15 Europe/Zurich

AT Auditorium (CERN)

Persistent currents is the conventional term used to indicate the effect of the magnetization of superconducting filaments on the field quality of accelerator magnets. The order of magnitude of the effect ranges from a few hundreds of ppm to fractions of percent, depending on the operating condition and the cycling procedure adopted for the magnet in question. It is for this reason that persistent currents have received considerable attention in the design, manufacturing, test and operation of all superconducting accelerators. In this presentation, I review the origins and properties of the effect and discuss the major results obtained in the main ring magnets of the Tevatron, HERA, RHIC and, mostly, the LHC. The results collected, and in particular the normal sextupole harmonic in the dipole magnets, satisfy a general scaling with the persistent current magnetization that is useful to interpret the finding and to estimate orders of magnitude in new designs.


Organiser(s): John Miles (AT-MAS)