Opacity and saturable absorption in solid-density plasmas generated by an x-ray free-electron-laser

<p>The arrival of 4th generation light-sources has opened up new regimes in x-ray–matter interactions. A billion times spectrally brighter than the preceding x-ray sources, free-electron-lasers (FELs) can deposit large amounts of energy into a system in less than 100 fs. Since the absorption o...