Computational Fluid Dynamics Modeling of Target Dynamics for Xray Free Electron Laser Heated Droplets*

High Energy Density (HED) Physics study matter under extreme states of pressure and temperature present in planetary interiors, astrophysical jets or fusion devices. Exciting data was obtained from single shot experiments recreating these conditions in laboratory using energetic laser/ion-beam drivers. In recent years, driven by the development towards high-repetition-rate drivers, collecting HED related data at a greater frequency is now within reach. For high-repetition-rate operation, liquid droplets can be used to provide a continuously refreshing target. However, one must make sure that extreme conditions produced during the preceding interaction and target debris do not degrade the next target. This is a challenging computational fluid dynamics (CFD) problem that needs to model not only the initial dynamics of the heated droplet, but also the late time interaction with the following droplets. Here, the code PISALE is used to study the case of a 1) liquid hydrogen and 2) liquid water droplet heated by an x-ray free electron laser. After showing high-resolution 2D results for a single heated droplet, we investigate in a 3D simulation the impact of the laser-droplet interaction on two subsequent droplets and compare it to available experimental data. We study the effect of surface tension on the subsequent droplets' deformation.