Ablation of PMMA, PTFE, and Si by soft x-rays emitted from hot dense plasma

The efficiency and threshold of ablation of polymethylmethacrylate (PMMA), polytetrafluoroethylene (PTFE), and monocrystalline silicon by single pulses of soft x-rays emitted from Z-pinch, plasma-focus, and laser-produced plasmas were investigated. The Z-pinch was driven by the S-300 pulsed-power machine (Kurchatov Institute, Moscow) and the plasma focus was realized in the PF-1000 machine (Institute of Plasma Physics and Laser Microfusion, Warsaw). Higher temperature plasma than with the discharge plasmas was obtained by focusing the near-infrared beam from the PALS high-power iodine laser system (Czech Academy of Sciences, Prague) on the surface of a metallic slab target. The role of nonthermal processes in x-ray ablation was evaluated. Possible ways to use x-ray ablation for micromachining are discussed.