High Current Beam Stability in Linear Accelerators

Equilibrium and stability constraints for high beam current linear accelerators are examined. Three general classes of linear accelerators are established depending on the geometry of the accelerating structure. For the case of klystron type geometry, of broad current interest for many applications, the equilibrium and stability properties are examined in detail. It is found that equilibrium constraints can readily be satisfied in the presence of a uniform guide magnetic field. Stability criteria for the longitudinal bunching mode and the transverse beam break up mode have been obtained and discussed. Stabilization mechanisms are suggested for the stable acceleration of multikiloamp particle beams.