Force-Reduced Superconducting Toroidal Magnet Coils

  • R. W. Boom
  • J. C. Laurence
Conference paper
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 15)


Force-free or force-reduced magnets have long been proposed as a means to overcome strength of material limitations in high fields. The basic idea involved is that conductors which are parallel to a magnetic field experience no forces since J × B = 0. The total structure, of course, cannot be force free. If a finite set of current-carrying conductors produces a magnetic field, then there is field energy and mechanical forces must exist to hold the magnet turns in place. Levy [1] has shown for the general case that the minimum structural mass necessary to hold magnets together either force-free or ordinary magnets, is proportional to the stored energy. Mills [2] and associates at Princeton have designed and constructed many force-free configurations with copper conductors in which forces were greatly decreased in a force-free subsection and transferred to the non-force-free magnet subsections.


Pitch Angle Longitudinal Field NASA Lewis Research Superconductor Wire 180A 236A 240A 184A 360A 
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Copyright information

© Springer Science+Business Media New York 1995

Authors and Affiliations

  • R. W. Boom
    • 1
  • J. C. Laurence
    • 2
  1. 1.Atomics InternationalCanoga ParkUSA
  2. 2.NASA Lewis Research CenterClevelandUSA

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