A model for superradiance and superfluorescence in free-electron lasers

An open-system model of the free-electron laser (FEL) which includes dissipative effects is presented. The concepts of superradiance and superfluorescence for the FEL are defined, and the conditions under which a cooperative emission of radiation should be expected are stated. The basic equations of motion for the electron dynamics are presented following a simple, heuristic approach, and a set of numerical results are discussed. A suitable master equation is presented which allows for a treatment of cooperative effects in FEL dynamics starting at the quantum statistical level and leads under suitable conditions to the equations of motion previously considered.