Numerical simulation of sputtering yield of 3D rough ion optic materials

Severe sputtering erosion of the ion thruster grid system under high-energy ion beam bombardment causes structural failure and shortens thruster lifetime. Using the Finite Element Triangle Mesh (FETM) method and Binary Collision Approximation (BCA) simulation, this study reconstructed grid material surfaces and investigated their sputtering behavior under ion bombardment, focusing on the dependence of graphite grid sputtering yield on incident ion energy, angle, ionic atomic fraction, ion species, and material type under rough surfaces. Key findings include a maximum sputtering yield at specific degrees of roughness for normal incidence, high-yield regions shifting to lower roughness with increased Xe implantation, higher yields (compared with other roughness-incident angle combinations) under low roughness and large incident angles (60–80°), non-monotonic yield variation with relative atomic mass ratio, and ion implantation significantly promoting yield for heavy ions (Xe on C) but reducing it for light ions (Ne on Mo). Numerical results on surface morphology and yield are consistent with experimental data, confirming the strong influence of rough surfaces and ion implantation on yield. These conclusions guide anti-sputtering grid manufacturing and improve erosion simulation accuracy.