Printing a 1.5 mm fusion target cone in one day
Published
Lawrence Livermore National Laboratory (LLNL) now makes a tiny part for its National Ignition Facility (NIF) targets by 3D printing it, and the time per part has dropped from ten days to one. The part is a compound parabolic concentrator, a cone about 1.5 mm long with a 20-micron narrow end, according to 3D Printing Industry.
The old route had many steps: diamond-turn a copper mandrel, coat it with gold and plastic, machine the shape, dissolve the mandrel out, then attach the cone to a support. The new route uses two-photon polymerization (2PP), where a laser focused to a spot under one micron cures resin only where two photons are absorbed at once. The cone prints as one assembly and needs no gold coating.
A printed cone was fielded in April 2026 on a gold disc target used to calibrate diagnostics, and LLNL says it performed as well as conventionally made parts. In September 2026 a design with printed parts went into a Discovery Science campaign on ion fast ignition, which needed the cone joined directly to an ion source. LLNL's Stadermann is quoted saying that would have been impossible without 2PP. Data from that first shot is still being analyzed.
Why it matters: the story is a manufacturing one, but it shows 2PP reaching the surface finish and size that precision hardware needs. Note that the article gives no material or roughness numbers.
Where else do parts this small and smooth need to be made?