Journal of Synchrotron Radiation (Mar 2024)

Ultrashort large-bandwidth X-ray free-electron laser generation with a dielectric-lined waveguide

  • Yiwen Liu,
  • Zhen Wang,
  • Lingjun Tu,
  • Chao Feng,
  • Zhentang Zhao

DOI
https://doi.org/10.1107/S1600577524000249
Journal volume & issue
Vol. 31, no. 2
pp. 243 – 251

Abstract

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Large-bandwidth pulses produced by cutting-edge X-ray free-electron lasers (FELs) are of great importance in research fields like material science and biology. In this paper, a new method to generate high-power ultrashort FEL pulses with tunable spectral bandwidth with spectral coherence using a dielectric-lined waveguide without interfering operation of linacs is proposed. By exploiting the passive and dephasingless wakefield at terahertz frequency excited by the beam, stable energy modulation can be achieved in the electron beam and large-bandwidth high-intensity soft X-ray radiation can be generated. Three-dimensional start-to-end simulations have been carried out and the results show that coherent radiation pulses with duration of a few femtoseconds and bandwidths ranging from 1.01% to 2.16% can be achieved by changing the undulator taper profile.

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