Amplification of Waves with Broad Frequency Spectrum in FEL with Longitudinal Electrostatic Undulator

摘要

Within the cubic nonlinear approximation framework we performed the analysis of space charge waves (SCWs) with broad frequency spectrum amplification in superheterodyne free electron laser (FEL) with longitudinal electrostatic undulator. We found out that the system under study allows realization of plural resonances of two types. We showed that in such FEL the SCW growth rates do not depend on the frequencies of the amplified waves. The lengths at which the SCW with broad frequency spectrum amplification occurs without distorting its shape are determined.