Design of a One-Dimensional Sextupole Using Semi-Analytic Methods

Sextupole magnets provide position-dependent momentum kicks and are tuned to provide the correct kicks to particles within a small acceptance region in phase space. Sextupoles are useful and even necessary in circular accelerators for chromaticity corrections. They are routinely used in most rings, i.e. CESR. Although sextupole magnets are necessary for particle energy corrections, they also have undesirable effects on dynamic aperture, especially because of their non-linear coupling term in the momentum kick. Studies of integrable systems suggest that there is an analytic way to create transport lattices with specific transfer matrices that limit the momentum kick to one dimension. A one-dimension sextupole is needed for chromaticity corrections: a horizontal sextupole for horizontal bending magnets. We know how to make a "composite" horizontal sextupole using regular 2D sextupoles and linear transfer matrices in an ideal thin-lens approximation. Thus, one could create an accelerator lattice using linear elements, in series with sextupole magnets to create a '1d sextupole'. This paper describes progress towards realizing a realistic focusing lattice resulting in a 1d sextupole.*
Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada