We discuss the energy spread induced by the FEL interaction on the e-beam itself. We analyze the problem from the dynamical point of view, studying how the energy spread evolves during the interaction. We present simple parametrization formulae, discuss their dynamical origin and prove that the so called fluctuation-dissipation theorem holds for homogeneously broadened operation only. © 1994.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics