Author: Cocco, D.
Paper Title Page
WEC03
Wavefront Preserving Optics for the LCLS Photon Transport System  
 
  • D. Cocco, C.L. Hardin, D.S. Morton, P. Stefan
    SLAC, Menlo Park, California, USA
  • J. Nicolás
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  The Linac Coherent Light Source (LCLS) is upgrading to a High Repetition Rate mode and to a higher quality of the wavefront. This poses extreme challenges to the optical components. A new approach to beamline design is needed, starting from a new way to assess the effect of slope and shape errors, to taking into account any potential source of distortion. Among the technical novelties the LCLS optics team is introducing, the most important are: a novel cooling scheme to maintain the mirror shape within 0.5 nm rms under heat load, the study of the effect of the cooling interface to the mirror surface, and new diagnostic systems. Ultra-flat mirrors with novel holder mechanisms have been recently installed. First results, showing the improvement of the beam quality, are expected in mid-June 2017. A controlled cleaning process to remove, in situ, carbonaceous contamination from carbon-based coatings will also be presented. It has been successfully implemented in the SXR mirrors. All the above tests and studies will be presented, as well as the effect seen on a six-year old mirror exposed to FEL for its entire lifetime.