Fusion research advances with 2PP for ignition capsule fabrication

A collaborative team of researchers from Lawrence Livermore National Laboratory, the Laboratory for Laser Energetics, General Atomics, and Los Alamos National Laboratory has achieved a major step forward in inertial confinement fusion (ICF) technology. Their recent study, published in Physics of Plasmas and led by G. Elijah Kemp and Xiaoxing Xia, demonstrated the successful use of the NanoOne two-photon polymerization (2PP) 3D printing platform from UpNano to fabricate complete fusion target capsules with unprecedented precision.

The capsules, measuring 3 millimeters in diameter, were printed with an integrated 120-micron-thick gyroidal foam layer at a density of 120 mg/cc. This delicate structure, built with a period of 80 microns and a theoretical wall thickness of just 4 microns, was manufactured in a single, continuous print. The achievement represents a breakthrough in scalability and reliability, moving closer to the production of leak-tight wetted foam capsules suitable for high-energy fusion experiments.

This innovation directly supports ongoing efforts to explore polar direct drive wetted foam concepts as potential neutron sources at the National Ignition Facility (NIF). Unlike the traditional laser indirect drive method that recently demonstrated ignition, polar direct drive offers several advantages: less damaging laser energy requirements, greater resilience to imperfections in targets and laser delivery, and significantly reduced target debris. These qualities make the approach attractive for both scientific neutron source applications and future inertial fusion energy systems.

The study highlights how additively manufactured capsules could simplify and accelerate target production while reducing costs. By integrating complex foam structures and vapor barriers into a single print, researchers are overcoming long-standing fabrication challenges. This work also opens pathways for improved hydrodynamic performance and enhanced robustness of fusion targets under extreme conditions.

As the first demonstrations of this technology move toward experimental application at NIF, the scientific community anticipates that such advancements could redefine what is possible in controlled fusion research. With continued progress, these techniques may pave the way toward more practical and sustainable paths to fusion energy, offering new tools for both fundamental science and future clean power generation.