Successful Midpoint Assessment of the IFE Targetry Hub Fusion Energy Project

In the “Inertial Fusion Energy (IFE) Targetry HUB for DT Inertial Fusion,” 15 partners, led by Fraunhofer IAF and Focused Energy GmbH, are developing materials, processes, and measurement methods for the fabrication and characterization of targets for laser-based inertial fusion. At the IFE Targetry HUB mid-term meeting, it became clear that since the project’s launch in December 2024, all work packages have achieved their interim goals, and the startups participating in the consortium have continued to establish themselves well in the market. The close collaboration between basic research, applied research, and industry is accelerating development.

In laser-driven inertial fusion, a hollow sphere filled with fuel (target capsule) is compressed by laser beams to such an extent that the densities and temperatures required for fusion reactions are achieved. Currently, no one in the world can produce deuterium-tritium-filled targets in sufficiently large quantities for use in a commercial fusion power plant. The central challenge is to produce fusion targets reliably, in sufficient quantities, and at an economical cost.

Midterm Progress

At the mid-term meeting of the IFE Targetry Hub on June 15 and 16, 2026, in Darmstadt, the participating research institutions, universities, and industrial companies presented their technical achievements and progress in the project.

Diamond Materials, a Fraunhofer IAF spin-off, has scaled up the production of hollow diamond spheres to up to 5000 pieces per batch. This has reduced the manufacturing costs per target in the CVD process many times over. The hollow spheres—i.e., the target capsules—are then filled with DT fuel for the upcoming fusion experiment.

To enable KIT to fill the targets with deuterium and tritium (DT) in Germany in the future, Fraunhofer IAF has drilled µ-channels into diamond spheres using UV picosecond lasers. These channels are smaller than the 10 to 15 µm standard set by the Lawrence Livermore National Laboratory (LLNL, USA). A channel diameter as small as possible is crucial for sufficiently maintaining the perfection of the target geometry.

Fraunhofer EZRT, a division of Fraunhofer IIS, and Fraunhofer IAF have verified the high material quality of the first target spheres, including the µ-channels, using X-ray microscopy (µ-CT).

Fraunhofer ILT is conducting research into the development of high-resolution, additively manufactured foam structures using multiphoton polymerization. It has developed photopolymers (photoresin formulations) for 2PP printing processes and carried out initial characterizations of the polymers—also under cryogenic conditions—with good test results.

At Fraunhofer IFAM, a surface treatment using an AD plasma coating process (Atmospheric Plasma Treatment) was successfully demonstrated. This process allows the surface to be smoothed cost-effectively and surface roughness to be specifically reduced. Furthermore, the deposition of a carbon coating was also demonstrated using the same process.

At KIT, an understanding of ice growth was gained for the subsequent fuel loading of various targets. Initially, ice was grown from hydrogen-deuterium mixtures, as these experiments do not require the use of radioactive tritium and are therefore much more accessible experimentally. However, since tritium is an integral component of fusion fuel, experiments with tritium are currently being prepared. To this end, work is underway at KIT to construct a cryostat for DT ice growth as well as for the subsequent DT loading. All work must be carried out in the cryostat, as the fuel exists exclusively in the solid phase under cryogenic conditions.

At Focused Energy, the new laboratories are operational, and production of the first targets has begun. In addition, various analytical methods have been established, and their functionality has been successfully demonstrated in-house.

Outlook: First laser tests planned for the second half

The next steps are now on the agenda for the second half of the project: The plan is to conduct the first systematic laser tests with the targets manufactured by the consortium and to further scale up the production processes.

Through its work, the IFE Targetry HUB consortium is strengthening Germany’s position in the international competition for commercial fusion energy and taking the vision of a laser-based fusion power plant a significant step forward.