Dispersively enhanced bunching in high-gain free-electron lasers

A free-electron laser based on a distributed optical klystron is studied using the 3D simulation code MEDUSA. The configuration consists of multiple wiggler segments separated by dipole chicanes. The chicanes ballistically enhance electron beam bunching and, in a properly designed system, can result in faster than exponential growth over the bulk of the interaction length. The principal constraint on the concept is the stringent requirements on beam quality.