• DOI:10.1103/PhysRevSTAB.16.120701
• Corpus ID: 118166051

Maximizing spectral flux from self-seeding hard x-ray free electron lasers

@article{Yang2013MaximizingSF,
  title={Maximizing spectral flux from self-seeding hard x-ray free electron lasers},
  author={Xi Yang and Yuri Shvyd’ko},
  journal={Physical Review Special Topics-accelerators and Beams},
  year={2013},
  volume={16},
  pages={120701}
}

• Xi Yang, Y. Shvyd’ko
• Published 20 September 2013
• Physics
• Physical Review Special Topics-accelerators and Beams

Fully coherent x-rays can be generated by self-seeding x-ray free-electron lasers (XFELs). Self-seeding by a forward Bragg diffraction (FBD) monochromator has been recently proposed [1] and demonstrated [2]. Characteristic time To of FBD determines the power, spectral, and time characteristics of the FBD seed [3]. Here we show that for a given electron bunch with duration sigma_e the spectral flux of the self-seeding XFEL can be maximized, and the spectral bandwidth can be respectively minimized by choosing To ~ sigma_e/pi and by optimizing the electron bunch delay tau_e. The choices of To and tau_e are not unique. In all cases, the maximum value of the spectral flux and the minimum bandwidth are primarily determined by sigma_e. Two-color seeding takes place To >> sigma_e/\pi. The studies are performed, for a Gaussian electron bunch distribution with the parameters, close to those used in the short-bunch (sigma_e ~ 5 fs) and long-bunch (sigma_e ~ 20 fs) operation modes of the LCLS XFEL.