High ablation pressures generated by laser ablation play a central role in direct-drive inertial confinement fusion (ICF) and high-pressure physics. The characteristics of ablation pressure at oblique incidence strongly affect target drive and compression. In this work, nanosecond laser ablation experiments on planar CH targets were performed on the Shen-Guang III prototype laser facility, and shock-velocity histories were measured for various laser intensities up to 2.29×10¹⁴ W/cm² at incidence angles ranging from 2.5° to 58°. One dimensional simulations show good agreement with the experimental results. On this basis, scaling laws for the time-dependent ablation pressure at oblique incidence are established, and a constant ablation pressure is achieved through optimization of the laser pulse shape. These results provide useful guidance for direct-drive ICF and related high-pressure physics studies.
 

ablation pressure,laser direct drive,oblique incidence