Instruments (Oct 2019)

Design of Comb Fabricated Halbach Undulators

  • Nathan Majernik,
  • James Rosenzweig

DOI
https://doi.org/10.3390/instruments3040058
Journal volume & issue
Vol. 3, no. 4
p. 58

Abstract

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An approach to fabricating Halbach array undulators using “combs” machined from single magnets is introduced. This technique is especially relevant to the fabrication of short period micro-undulators with period lengths considerably less than the few-centimeter-scale typical of current undulators. Manual, magnet-by-magnet assembly of micro-undulators would require the manipulation and alignment of thousands of magnets smaller than a grain of rice: comb fabrication dramatically increases the size of the basic unit cell of assembly with no increase in undulator period by creating many periods from a single piece, in a single machining modality. Further, as these comb teeth are intrinsically indexed to each other, tolerances are dictated by a single manufacturing step rather than accumulating errors by assembling many tiny magnets relative to each other. Different Halbach geometries, including M ′ = 2 , M ′ = 4 , isosceles triangle, and hybrid, are examined both from a theoretical perspective and with 3D magnetostatic simulations.

Keywords