Picosecond time-resolved x-ray refectivity of a laser-heated amorphous carbon film
We demonstrate thin film x-ray reflectivity measurements with picosecond time resolution. Amorphous carbon films with a thickness of 46 nm were excited with laser pulses characterized by 100 fs duration, a wavelength of 800 nm, and a fluence of 70 mJ/cm(2). The laser-induced stress caused a rapid expansion of the thin film followed by a relaxation of the film thickness as heat diffused into the si