THEORY OF SOLITARY HOLES IN COASTING BEAMS

A self-consistent theory of solitary hole structures in coasting beams is presented. These phase space vortices are known from particle simu lations and appear, e.g., due to a resistive wall instability. The ana lysis reveals new intrinsic nonlinear modes which owe their existence to a deficiency of particles trapped in the potential well, showing up as notches in the thermal range of the distribution function, where l inear wave theory would predict strong Landau damping. This sheds ligh t on the spectrum of small amplitude perturbations proving the incompl eteness of linear and associated nonlinear wave theories in the kineti c regime and offers a new interpretation of recent synchrotron experim ents.