Focus characterization at an X-ray free-electron laser by coherent scattering and speckle analysis

J Synchrotron Radiat. 2015 May;22(3):599-605. doi: 10.1107/S1600577515004361. Epub 2015 Apr 14.

Abstract

X-ray focus optimization and characterization based on coherent scattering and quantitative speckle size measurements was demonstrated at the Linac Coherent Light Source. Its performance as a single-pulse free-electron laser beam diagnostic was tested for two typical focusing configurations. The results derived from the speckle size/shape analysis show the effectiveness of this technique in finding the focus' location, size and shape. In addition, its single-pulse compatibility enables users to capture pulse-to-pulse fluctuations in focus properties compared with other techniques that require scanning and averaging.

Keywords: X-ray FEL; focusing; speckle.

Publication types

  • Research Support, Non-U.S. Gov't