Reabsorption of soft x-ray emission at high x-ray free-electron laser fluences

Phys Rev Lett. 2014 Oct 10;113(15):153002. doi: 10.1103/PhysRevLett.113.153002. Epub 2014 Oct 6.

Abstract

We report on oxygen K-edge soft x-ray emission spectroscopy from a liquid water jet at the Linac Coherent Light Source. We observe significant changes in the spectral content when tuning over a wide range of incident x-ray fluences. In addition the total emission yield decreases at high fluences. These modifications result from reabsorption of x-ray emission by valence-excited molecules generated by the Auger cascade. Our observations have major implications for future x-ray emission studies at intense x-ray sources. We highlight the importance of the x-ray pulse length with respect to the core-hole lifetime.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Absorption, Physicochemical
  • Lasers
  • Models, Theoretical*
  • Spectrometry, X-Ray Emission / methods*
  • X-Rays