Development of a Non-Axisymmetric Permanent Magnet Focusing System for Elliptic Charged-Particle Beams

A high-brightness elliptic electron or positron beam is a novel device that has wide applications in high energy accelerators. In addition to the high-energy accelerator applications, high-brightness elliptic charged-particle (electron, muon, proton, antiproton, and ion) beams have wide applications in other accelerators for nuclear physics research and high-energy density physics research. The Phase I project successfully designed an elliptic electron beam system, fabricated a periodic permanent magnet stack prototype, and tested the prototype in agreement with three-dimensional design predictions. The Phase II project will: (1) Demonstrate focusing of a periodically twisting elliptic electron beam using a periodic non-axisymmetric permanent magnet stack consisting of an array of elliptic dipole magnets; (2) Design a periodic non-axisymmetric permanent magnet stack consisting of a quadrupole magnet and an array of elliptic dipole magnets for the focusing of a non-twisting elliptic electron beam; and (3) Demonstrate the focusing of a non-twisting elliptic electron beam using a periodic non-axisymmetric permanent magnet stack consisting of a quadrupole magnet and an array of elliptic dipole magnets. Commercial Applications and other Benefits as described by the awardee: Demonstrating non-axisymmetric permanent magnet systems for elliptic beam focusing will not only be a significant technical achievement, but will also support the development of elliptic-beam-based RF source and accelerator products in Phase III.