The effect of high-Z dopant on the ablation of carbon–hydrogen polymer target

Abstract

High-Z dopants such as chlorine, bromine and silicon in carbon–hydrogen polymer (CH) targets play a crucial role during the ablation of inertial confinement fusion (ICF). These dopants can serve as diagnostic tools in experiments and mitigate hot electron preheating, but they also influence the laser ablation. In this paper, the process of high-power laser ablating doped CH targets has been studied through radiation hydrodynamic simulations. Our findings reveal that the laser absorption rate in the doped targets increase as a result of the increasing electron-ion collision frequency. This leads to the increase of the electron, ion and radiation temperatures. Furthermore, high-Z dopants contribute to a decrease in the ablation pressure, which tends to a constant. Moreover, the saturation phenomenon of the mass ablation rate has been found. For the targets with low doping ratios (e.g. 6.25%–12.5%), the mass ablation rate increases until reaching the saturation at a doping ratio of 18.75%, after which it decreases. This indicates that an appropriate doping ratio can increase the laser absorption and ablation. The results are helpful to comprehensively understand the effects of high-Z dopant on all stages of ICF.