High gain harmonic generation X-ray free electron laser

We present the calculation of the performance of a high gain harmonic generation (HGHG) X-ray free electron laser (FEL) based on a high quality electron beam from the proposed Photoinjected Energy Recovery Linac (PERL) at the NSLS. We consider several sets of e-beam parameters. The calculation indicates that it is possible to produce a fully coherent FEL with a wavelength around 10 Angstrom, with a peak power of several GW. The high order harmonics will also be produced with a significant amount of peak power. One further attractive feature is the possibility to produce ultra short radiation pulses of about 10 fs based on such an HGHG scheme.