A field-cancellation algorithm for constructing economical planar permanent magnet (PM) multipoles with large high-quality field apertures

R. Tatchyn
Proceedings of the 1997 Particle Accelerator Conference (Cat. No.97CH36167)  
In recent years studies have been initiated on a new class of multipole field generators consisting of cuboid planar permanent magnet (PM) pieces arranged in biplanar arrays of 2-fold rotational symmetry. These structures, first introduced for Free Electron Laser (FEL) applications, are based on reducing the rotational symmetry of conventional N-pole field generators from N-fold to 2-fold. One consequence of this reduction is a large higher-multipole content in a planar PM multipole's field at
more » ... istances relatively close to the structure's axis, making it generally unsuitable for applications requiring a large high-quality field aperture. In this paper we outline an economical field-cancellation algorithm that can substantially decrease the harmonic content of a planar PM's field without breaking its biplanar geometry or 2fold rotational symmetry. 2639 0-7803-4376-X/98/$10.00
doi:10.1109/pac.1997.751300 fatcat:qisbkjzyyrdb3ghrau6lbvezyq