Equilibrium theory of an intense elliptic beam for high-power ribbon-beam klystron applications

Realization of the concept for a high-power ribbon- beam klystron (RBK) requires a novel large-aspect ratio elliptic electron beam instead of a conventional circular electron beam. In this paper, a cold-fluid equilibrium theory of a nearly non-twisting intense elliptic charged- particle beam is presented. The equilibrium theory is applied in designs of elliptic electron beams for high- power RBKs. Results of the design and simulation of a 20:1 elliptic electron beam for a 10 MW, 1.3 GHz International Linear Collider (ILC) RBK are discussed.