62 / 2025-03-09 19:22:06

Effects of high-Z dopant on laser ablating polymer targets

high-Z dopant;,Raleigh-Taylor instability;,laser-driven fusion

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 work, we studied high-power laser ablating doped CH targets through radiation hydrodynamic simulations. It is shown that the laser absorption rate in the doped targets increase because 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. The saturation phenomenon of the mass ablation rate is found. This indicates that an appropriate doping ratio can increase the laser absorption and ablation. Then the high-Z dopants can reduce the ablative Raleigh-Taylor instability originated from the inner interface, and this influence is much more significant for the short wavelength perturbations comparing to that of the long wavelength perturbations. The results are helpful to comprehensively understand the effects of high-Z dopant on all stages of ICF.