Rocking curve width FWHM and maximum temperature on a channel-cut Si crystal as a function of the total absorbed power. Triangles and circles represent experimental data, the red line ALPX-h3k corresponds to previous calculated rocking curve widths FWHM with a cooling coefficient of 3000 W m−2 K−1 (Zhang et al., 2003), the green line CTEX-h1k4 represents recalculated results with the coefficient of thermal expansion input by `MP, CTEX,…'. The corresponding maximum crystal temperature curves are the dashed red line h3k, and dashed green line h1k4. Here h1k4 and h3k correspond to cooling coefficients of 1400 and 3000 W m−2 K−1. The green lines correspond to the corrected FEA results.