Second project meeting of the IFE Targetry Hub for laser-based inertial fusion

On July 10 and 11, 2025, the second project meeting of the IFE Targetry Hub took place at the Tritium Laboratory of the Karlsruhe Institute of Technology (KIT). The first plastic-based targets were handed over for pre-characterization, and important specifications from the successful fusion experiments at the National Ignition Facility (NIF) of the Lawrence Livermore National Laboratory (LLNL) were shared. The IFE Targetry Hub investigates suitable materials and processes for the functional and cost-efficiently scalable production and characterization of targets as a basic technology for laser-based inertial fusion (IFE).

Eine Gruppe von ca. 25 Menschen schaut vor einem Waldstück auf einer trockenen Wiese direkt in die Kamera. Im Hintergrund ist der Teil eines Gebäudes zu sehen. — © KIT
Gruppenbild der Teilnehmenden am zweiten Projekttreffen des IFE Targetry Hub am Tritium-Labor des KIT

Diamond sphere size comparison — © Fraunhofer IAF
To date, targets for laser-based inertial fusion have been made of microcrystalline diamond. The IFE Targetry Hub is working on developing plastic targets to achieve greater cost efficiency.

During the second project meeting of the IFE Targetry Hub on July 10 and 11, 2025, at the KIT Tritium Laboratory, Focused Energy GmbH handed over the first plastic-based targets manufactured in the project to the other consortium partners for pre-characterization. Since, according to current estimates, approximately 1 million targets are required daily to operate a fusion power plant, the partners are working on more cost-efficient manufacturing methods for series production. In laser-based inertial fusion, targets are bombarded with laser pulses to cause the deuterium-tritium mixture inside them to undergo a fusion reaction.

Direct drive instead of indirect drive approach

A modification of the fusion excitation process allows the targets to be constructed more simply: The indirect drive approach used by NIF is to be replaced by the direct drive approach, which is more challenging to implement but more efficient. In direct drive, the laser fires directly at the target, whereas in indirect drive, the laser pulse is first converted into X-rays inside the target. In addition, polymers are to be used as a cheaper material than the microcrystalline diamond used to date. The handover of the first plastic targets for further characterization therefore represents a significant step forward in the project.

Key figures collected by NIF

The Fraunhofer IAF has contributed key figures on target properties published by the NIF during the successful demonstration in December 2022. In further follow-up experiments, the NIF has even exceeded the net energy gain achieved at that time in relation to the target energy balance. The key figures provide important points of reference for understanding which target properties are relevant for a future power plant.

During the course of the project, Fraunhofer IAF will also continue the target characterization and drilling of microchannels in diamond and plastic targets. One of the consortium’s goals is to use the channels to introduce the hydrogen isotopes deuterium and tritium, which are required for the fusion reaction, into the targets.

About the IFE Targetry Hub

The IFE Targetry Hub is a joint project funded by the German Federal Ministry of Research, Technology and Space (BMFTR) in which 15 partners from research and industry, led by Fraunhofer IAF and Focused Energy GmbH, are developing targets that are a key component in laser-based inertial fusion. The partners contribute their diverse expertise from basic research, applied research and industry to jointly investigate suitable materials, processes and characterization methods for targets for laser-based inertial fusion. Suitable targets are a key technology on the road to laser-based fusion power plants.