How silicon X-ray optics can survive against FEL power

A Brazilian research group recently discussed the thermal influence of soft X-ray free-electron-laser (FEL) pulses on silicon substrate. Such analysis is important, because the peak power of a single FEL pulse is roughly four orders of magnitude higher than that in conventional synchrotron light facilities. Their detailed time-evolution analysis indicates that in a worst case scenario, the second pulse could be adversely affected by dynamic thermal distortion induced by the preceding pulse. For more information, see the paper, "Thermoelastic analysis of a silicon surface under x-ray free-electron-laser irradiation", A. R. B. de Castro et al., Rev. Sci. Instrum. 81, 073102 (2010).