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. Once developed, a large-aspectratio elliptic electron beam would enable the development of L-band ribbon-beam klystrons (RBKs) or sheet-beam klystrons (SBKs), which are more efficient than the multi-beam klystrons (MBKs) for the International Linear Collider (ILC). Also, elliptic electron and positron sources would be more suitable for beam injections, because sheetlike electron and positron bunches are brought to collision in the interaction section in the ILC. Finally, high-brightness elliptic charged-particle beams can be naturally matched into alternating gradient focusing systems, where the transverse section of the beam is a pulsating ellipse. This project will demonstrate a high-intensity elliptic beam system, including a thermionic elliptic electron gun for elliptic beam generation, a periodic permanent magnet system for elliptic beam focusing, and a depressed collector. The beam will be characterized and compared to theoretical and simulation predictions. Commercial Applications and other Benefits as described by the awardee: In addition to the high-energy accelerator applications, high-brightness elliptic charged-particle (electron, muon, proton, antiproton, and ion) beams should have wide applications in other accelerators for nuclear physics research and high-energy density physics research