We present computational study of the interaction of femtosecond XUV (13.5 nm wavelength) laser pulses with 50 nm thin Ru films. With our calculations we model the damage experiments that was performed at Free-Electron LASer in Hamburg (FLASH) –. Ru is chosen as optically favorable material for grazing incidence reflective mirrors.
The performed simulations consist of two parts. First, the effect of electron cascading induced after absorption of XUV photons is studied using an event-by-event Monte Carlo code XCASCADE . Time of cascading and ballistic range of non-thermalized electrons are calculated. Second, the evolution of electron and lattice temperatures in the regime of thermal non-equilibrium together with atomic motion in irradiated Ru are modeled with a combination of two temperature hydrodynamics  and molecular dynamics . Our calculations showed that the mechanism responsible for the ablation of Ru observed in the experiment is spallation in the stress confinement regime. The processes of melting, cavitation, spallation and recrystallization are modeled. The results show good agreement with the experimental observations.
|Publication status||Published - 17 Sep 2018|
|Event||4th FELs OF EUROPE workshop on FEL Photon Diagnostics, Instrumentation, and Beamline Design, PhotonDiag 2018 - Hamburg, Germany|
Duration: 17 Sep 2018 → 19 Sep 2018
Conference number: 4
|Conference||4th FELs OF EUROPE workshop on FEL Photon Diagnostics, Instrumentation, and Beamline Design, PhotonDiag 2018|
|Abbreviated title||PhotonDiag 2018|
|Period||17/09/18 → 19/09/18|