Synchrotron-radiation-induced damages in optical materials

Synchrotron radiation sources and free electron lasers (FEL) represent practical approaches to produce high photon flux down to the VUV wavelength region or the X-ray spectral range. But operating brilliant photon sources requires to overcome severe and crucial damage problems. Optical material are exposed to high power broad band radiation extending from far IR to gamma rays. Typically, materials suffer series of picoseconds pulses at MHz repetition rate with multi photon energy ranging from few eV to several keV. Damages observed on some oxide and fluo ride materials irradiated with synchrotron radiation and UV free electron lasers are reviewed. Surface and bulk damages, increased roughness, modification of sp ectral properties and change of crystalline structures are observed and described. Contamination elements like carbon are detected as major aging factor.