High-Flux Ion Acceleration in Structured Foam Targets

Laser-driven ion sources are critical for fast ignition schemes in inertial confinement fusion. Short-pulse lasers are excellent tools for generating relativistic, ps-duration ions, but achieving the ion flux demanded by fast ignition remains an open challenge. Custom 3D-printed targets, enabled by two-photon polymerization, can tune average plasma densities to the near-critical limit and greatly increase laser-to-ion conversion efficiency. Microstructured targets are investigated using particle-in-cell simulations to explore acceleration mechanisms in the near-critical regime and assess the role of relativistic transparency in the generation of high-flux and high-energy ions.