Tests of planar permanent magnet multipole focusing elements

Abstract In recent work, planar configurations of permanent magnets were proposed as substitutes for conventional current-driven iron quadrupoles in applications limited by small aperture sizes and featuring small beam occupation diameters. Important examples include the configuring of focusing lattices in small-gap insertion devices, and the implementation of compact mini-beta sections on linear or circular machines. In subsequent analysis, this approach was extended to sextupoles and higher-order multipoles. In this paper we report initial measurements conducted at the Stanford Linear Accelerator Center on recently fabricated planar permanent magnet quadrupoles and sextupoles configured out of SmCo and NdFe/B.