Cascading stages of seeded free electron laser (FEL) is a promising way to produce fully coherent X-ray radiations. We study a new approach to produce coherent hard X-rays by cascading the recently proposed phase-merging enhanced harmonic generation (PEHG). The scheme consists of one dogleg and two PEHG configurations, which may be one of the leading candidates for the extracted undulator branch in future X-ray FEL facilities. FEL physics studies show that such a scheme is feasible within the present technology and can provide high brightness X-ray radiation pulses with narrow bandwidth and fully coherence, and the radiated peak power at 1 angstrom wavelength converted from an initial 200 nm seed laser is over 2 GW.
@article{arxiv.1602.07066,
title = {Fully coherent hard X-ray generation by two-stage of Phase-merging Enhanced Harmonic Generation},
author = {Guanglei Wang and Weiqing Zhang and Xueming Yang and Chao Feng and Haixiao Deng},
journal= {arXiv preprint arXiv:1602.07066},
year = {2016}
}