Yl. Bogomolov et al., CHAOTIC PARTICLE DECELERATION AND FEL EFFICIENCY ENHANCEMENT WITH AN INCOHERENT PUMP WAVE OR A STOCHASTIC UNDULATOR, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 358(1-3), 1995, pp. 171-173
For efficiency enhancement of FELs driven by high-current low-quality
electron beams we propose the use of incoherent pump waves or stochast
ic undulators.