High brilliance, femtosecond x-ray sources with FEL assist

摘要

We describe EFSX, a means of using currently available RF-linac technology to produce multi-kiloampere pulses of 100 to 300 fs duration for use in the generation of extremely short bursts of X- rays. The key technical concept, the use of the free electron laser as a bunching mechanism, has been proposed for confirmation in the ELFA experiment. By operating the FEL buncher in the strong super- radiant regime, one should be able to shorten the X-ray pulses to 10--30 fs duration. As laser photo-cathode sources of beams evolve to yield ever better emittances, the EFSX could be easily retrofitted to furnish the drive beam for an efficient X-ray free electron laser. Potential debunching effects are discussed. Finally we describe a low energy test experiment.