The future of energy meets the manufacturing revolution

Marvel Fusion GmbH, which was founded in Munich in 2019, sees fusion energy as the next major development step in the history of energy use and therefore as a potential driver of prosperity and technological progress.
The presentation by Dr. Sophia Spitzer, Lead Business Development and Market Strategy at Marvel, focused on the classification of fusion energy: small atomic nuclei, specifically hydrogen isotopes, fuse together and release energy in the process. A distinction is made between two major technological directions: Magnetic fusion and laser fusion. Laser fusion has gained particularly dynamic importance in recent years and achieved a scientific breakthrough in 2022: a net energy gain within narrow system limits was demonstrated for the first time at the US National Ignition Facility.

At the same time, Dr. Spitzer's presentation made it clear that this success cannot yet be equated with an economically viable power plant concept. The efficiency losses along the entire process chain are crucial: in the experiment mentioned, around 400 MJ of electrical energy was used to generate a laser pulse of around 2 MJ - which corresponds to an efficiency of only around 0.5 percent. In addition, there are further losses during energy transfer to the fusion target.

This is where Marvel Fusion comes in with two central levers:

• significantly more efficient lasers, which should achieve a "socket efficiency" of around 10 percent
• optimized fuel targets with nanostructures that significantly improve the coupling of laser energy.

The concept presented is based on laser pulses hitting specially developed targets at high frequency. The nanostructures ensure that light is efficiently converted into accelerated particles and radiation, which in turn trigger fusion reactions in a surrounding fuel ring. The key innovation is that the fuel is in a solid form at room temperature and does not need to be cooled significantly. This considerably simplifies the subsequent power plant architecture.
Dr. Spitzer outlined a multi-stage development plan for the path to commercialization:

1. Proof of concept of the physical approach by 2024
2. Construction and demonstration of a proprietary, highly efficient laser by 2027
3. Physics milestone with focus on scaling by 2028
4. Development of a power plant pilot in the early 2030s
5. First commercial power plants from the mid-2030s

The company is already conducting experiments at several international laser facilities, including in Garching, Romania and the USA. Progress has been made in the production of nanostructures in particular: instead of individual targets, thousands of structures can now be produced per wafer. This is done in collaboration with the well-known semiconductor research institute imec and shows how much Fusion benefits from advances in related deep-tech areas.
Another focus is on the industrialization of fusion technology. In parallel to the physical concept validation, Marvel Fusion is also further developing the power plant side. An initial power plant study has already been developed together with Siemens Energy. The design envisages several hundred lasers aligned with a central reactor building. The heat generated is to be absorbed in liquid salts and then converted into electricity via conventional steam cycles. The planned pilot is in the order of around 120 megawatts.
Overall, the presentation made it clear that progress in fusion is not solely dependent on physical breakthroughs, but also on system integration, industrial partnerships and parallel development.

Additive manufacturing for fusion components

The Fraunhofer Institute for Casting, Composite and Processing Technology (IGCV) in Augsburg is a leading institution for production technology research. In the context of fusion technology, the institute focuses, among other things, on the additive manufacturing of high-performance materials, which are crucial for applications with extreme thermal, mechanical and neutronic loads, such as those found in fusion reactors.
IGCV department head Dr. Georg Schlick showed in the webinar what role modern manufacturing technologies play in the realization of fusion power plants. Heat loads of up to 20 MW per square meter, and in tests even up to 45 MW per square meter, occur in the highly stressed areas. Added to this are thermally induced stresses, material erosion by the plasma and a very high neutron load, which changes the structure of materials and severely restricts the choice of materials. An important goal is therefore to select materials in such a way that they do not themselves become radioactive in a problematic way.

Using magnetic fusion as an example, Schlick explained in particular the requirements for divertors, i.e. components for dissipating heat and removing the "fusion ash". Tungsten has established itself here as a plasma-facing material and copper alloys for heat transport. However, the problem is that tungsten is difficult to process and conventional solutions are very complex in terms of materials and production technology.

Additive manufacturing opens up new possibilities here. The Fraunhofer IGCV is working on producing complex lattice structures from tungsten, which are then infiltrated with copper. This can create composite structures that can withstand high thermal loads and at the same time better compensate for differences in thermal expansion between the materials. Such geometries would be difficult or impossible to realize with conventional processes.

In addition, multi-material processes were presented in which two materials are combined directly within an additive manufacturing process. The aim is to process copper and tungsten together in a single 3D printing process in the future - which is technologically very demanding, but opens up new degrees of freedom for the design of highly resilient components.

Another important field of research at the IGCV is complex cooling structures. Additive manufacturing makes it possible to produce internal cooling channels and functionally integrated components that previously had to be assembled from many individual parts or soldered. This reduces potential weak points and creates new design possibilities. The challenges here include

• Quality assurance and process monitoring
• Helium leak-tightness of large copper structures
• Reliable depowdering of complex channels
• and experimental testing under realistic load conditions.

High-load tests show that additive manufacturing in fusion research is already being considered not just as a concept, but as a serious solution. In the long term, the aim is to further develop these processes towards industrialization and scalability so that fusion companies can obtain directly usable components on a larger scale.

The presentations impressively demonstrated that deep tech can become a driver of transformation when scientific excellence, industrial implementation and new manufacturing technologies come together. Marvel Fusion is an example of the attempt to transfer nuclear fusion from research into a commercial energy application. The Fraunhofer IGCV in turn makes it clear that this can only succeed if the materials, components and production processes for the extreme requirements of a fusion power plant are also mastered. This made it clear in the webinar that the transformation is not the result of a single innovation, but of the interplay between physics, materials science, production technology and industrial scaling.