IFE Targetry HUB

Nuclear fusion has the potential to solve the world’s energy needs in the 2040s. To pave the way for Germany’s first fusion power plant, the federal government launched the “Fusion 2040” funding program in 2024 with a total volume of more than one billion euros. In December 2024, the IFE Targetry HUB was launched as part of this program, with the aim of researching basic technologies for targets for laser-based inertial confinement fusion. Fraunhofer IAF is leading the joint project together with Focused Energy GmbH, which consists of 15 partners from research and industry.

The partners are contributing their different expertise from basic and applied research and industry to jointly researching suitable materials and processes for the functional and cost-efficiently scalable production and characterization of targets for laser-based inertial confinement fusion. These targets are a bottleneck for resource-efficient nuclear fusion and are therefore a key technology on the way to an inexpensive laser-based fusion power plant of the future.

Fraunhofer IAF's contribution

Fraunhofer IAF has been working on the production of spherical diamonds that form the basis of today’s target development starting in the late 1990s. In addition to its expertise in diamond growth, Fraunhofer IAF contributes its know-how and infrastructure in the field of microstructure technologies with regard to surface treatments of spherical targets and material characterization to the IFE Targetry HUB. The goal of Fraunhofer IAF is to ensure knowledge transfer within the network and to test and evaluate the suitability of the targets manufactured by the network partners for inertial confinement fusion. To this end, targets are fired in experimental tests to simulate the conditions of inertial confinement fusion.

In the inertial confinement fusion process, an approximately 2-millimeter diamond hollow sphere, the so-called target, is indirectly irradiated with frozen fuel (a deuterium-tritium mixture) using high-intensity laser radiation. The laser radiation is converted into X-rays, causing the diamond sphere to reach a hundred times its density and a temperature of up to 120 million degrees Celsius. When the diamond sphere vaporizes, the fuel is compressed under enormous pressure and heated at the same time. This highly compressed state enables the fusion reaction: the positively charged atomic nuclei overcome their mutual repulsion and fuse to form a new, energetically more favorable nucleus, releasing energy in the process.

Perfect diamond sphere as the ideal target

An ultra-precise spherical shape, an extremely polished surface and perfect material are the prerequisites for the target to be compressed in the fusion experiment without deforming. Synthetic diamond is ideal due to its unique properties: the tiny diamond hollow spheres can be formed into a perfectly round shape and the absorption properties for X-rays can be tailored by introducing foreign atoms.

The technology for producing the diamond sphere, as used in the experiment at LLNL, was developed at Fraunhofer IAF decades ago. The spin-off Diamond Materials has further developed and optimized the concept. Today, the spherical wall consists of several customized layers with different material properties. In this way, the researchers at Fraunhofer IAF and Diamond Materials have made an important contribution to research into fusion energy as the energy source of the future.