Two-photon polymerization for inertial fusion energy target fabrication

Abstract This study focuses on optimizing the fabrication of foam targets for laser-driven inertial fusion energy using two-photon polymerization (2PP). 2PP offers nanoscale precision, enabling the fabrication of foams with precise control over structure, strut thickness, and pore size distribution. Due to its repeatable and deterministic fabrication, 2PP is a promising technique for studying crucial target parameters on the path towards a fusion power plant. However, 2PP faces challenges such as stitching errors in large prints, data limitations, and extended printing times, which limit it to single-piece production. We investigate the impact of foam structures and printing parameters on the foam density and demonstrate the successful fabrication of a foam-shell target for the proton fast ignition approach. By optimizing the printing path, we achieved a reduction in file size by one order of magnitude and printing time by a factor of four for the fabrication of a hexagonal honeycomb structure. Additionally, this research identifies and addresses key limitations and provides a detailed outlook for future improvements.