TUOA03
LANL, Los Alamos, New Mexico, USA
The proposed Matter-Radiation Interactions in Extremes (MaRIE) hard X-ray facility at Los Alamos National Laboratory (LANL) has some user requirements that require longitudinal bandwidths that are an order of magnitude smaller than the bandwidths provided by a SASE FEL. We discuss two novel laser-based harmonic generation schemes for x-ray FELs which could be incorporated into x-ray FELs in order to achieve these bandwidths. The first scheme is a hybrid of Echo-Enabled Harmonic Generation (EEHG) and High-Gain Harmonic Generation (HGHG), which only requires a single laser with relatively low power, compared with EEHG. The second scheme uses a pair of Emittance Exchangers (EEX) after a laser modulator, in order to compress the modulation by a large factor. The strengths and design constraints of these schemes will be discussed, and a general formulism for studying the evolution of bandwidth and bunching factors in a complex seeding scheme will be presented [Yampolsky, arXiv:111.0553v1]. We will show how the hybrid EEHG-HGHG scheme can be incorporated into the NGLS for increased seeding performance.
