Longitudinal Phase Space Disruption in Magnetic Bunch Compressors

It is now well-established [2, 3] that high-charge ultra-short bunches can radiate coherently on curved trajectories (coherent synchrotron radiation). The two main consequences of such an effect are (1) an energy redistribution within the bunch, (2) a potential transverse emittance dilution in the bending plane. This effect is especially important in the foreseen next generation of free-electron laser driver linacs and linear colliders. In this paper after briefly discussing the general aspects of coherent synchrotron radiation (CSR), we report on recent experimental results obtained at the Tesla Test Facility I and compare them with numerical simulations. Schemes for reducing the impact of CSR on the beam dynamics are also discussed in the frame of the TESLA X-ray FEL project