Fig. 2: Measured X-tray transmission images and estimating the electron temperature.
From: Spatiotemporal dynamics of fast electron heating in solid-density matter via XFEL
a–i Experimental transmission ratio images at 9.05, 8.92, and 8.05 keV for various timing delays. Averaged horizontal lineouts of the image around Y = 0 µm are superposed in each image. j A transmission profile of a 2 μm thick cold solid Cu foil and the Fermi-Dirac distribution at electron temperatures of 10 and 30 eV. The shaded vertical bars indicate the XFEL’s photon energies used with a spectral bandwidth of 50 eV. Transmission changes increase at 9.05 and 9.12 keV, while it decreases at 8.92 keV. k Relative changes in transmission are calculated using the Fermi–Dirac distribution as a function of Te. The shading indicates the minimum and maximum temperature range set by the spectral bandwidth for each photon energy.
