High Gradient Quadrupoles for Low Emittance Synchrtrons

A new lattice design has been proposed recently based on a Complex-Bend concept [1,2] for low emittance syn-chrotrons. The dipoles of a standard DBA lattice are replaced in the Complex Bend by high-gradient (~ 450 T/m) quadrupoles interleaved between discrete dipoles. In another version of the Complex Bend [3] the high gradient quadrupoles are displaced transversely along the beam trajectory to generate the required dipole field. In the latter version the quadrupole strength is reduced to ~ 250 T/m for a lattice that will conform to the layout of the existing NSLS-II 3-GeV storage ring. In this paper we present conceptual designs of a Halbach permanent-magnet (PM) quadrupole, a hybrid PM quadrupole, and a superconducting quadrupole, that can produce the de-sired quadrupole strengths for the Complex Bend appli-cation. REFERENCES [1] T. Shaftan, V. Smaluk and G. Wang, ’The Concept of Com-plex Bend’, NSLS-II Tech note No. 276, Jan 2018. [2] G. Wang et al., ’Complex Bend: Strong-focusing magnet for low emittance synchrotrons’, Physical Review Accelerators and Beams, 21, 100703 (2018). [3] G. Wang et al., ’Complex Bend II’, paper submitted to Physi-cal Review Accelerators and Beams.
Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia