Artificial sun: Nuclear fusion closes in, new method can tackle key challenges

In this sphere, inertial fusion energy experiments have been a primary focus of researchers. Such experiments aim to recreate the conditions necessary for fusion by compressing a fuel pellet to extremely high densities.

Fusion fuel must be held in a highly precise configuration

For inertial fusion energy experiments, the fuel must be held in a very precise configuration, and one promising material to achieve this is a type of porous foam known as nanofoam, according to a report.

However, understanding how well these nanofoams perform in such experiments is challenging, as existing techniques either destroy the delicate structures or lack the resolution needed to study them in detail, reported Nano Magazine.

But now a novel X-ray imaging technique is expected to address these issues.

New X-ray technique generates images by analyzing the patterns of photons

Based on a method known as ptychographic imaging, the technique involves generating images by analyzing the patterns of photons scattered off a sample.

It has enabled researchers to resolve the three-dimensional nanostructure of a copper foam with unprecedented precision, directly relevant to fusion experiments, as per the report.

3D volume technique at a free-electron laser is a first-of-its-kind measurement

“This type of 3D volume technique at a free-electron laser is a first-of-its-kind measurement,” stated Adra Carr, a research scientist at Los Alamos National Laboratory and the lead author of the work, which was published in Nano Letters on August 1.

Able to reconstruct the original sample with nanoscale resolution, the method effectively creates a detailed 3D image of the foam’s internal structure. The ability to rotate the samples during imaging further enhances understanding of the foam’s three-dimensional architecture.

Technique leverages the coherence and the brilliance of the X-ray free-electron laser

Arianna Gleason, a senior staff scientist at the Department of Energy’s SLAC National Accelerator Laboratory, stated that this new technique leverages the coherence and the brilliance of the X-ray free-electron laser. “We were able to interrogate the foam in a way that few other methods could achieve.”

The generated images showed that the copper foam is not as uniform as expected. Many of the thin shells of foam were distorted, merged or open – variations that could affect their performance in inertial confinement fusion experiments.

That kind of information could be used to optimize foam fabrication methods and tailor these materials for fusion experiments, according to National Accelerator Laboratory.

Finding can help in development of fusion energy

The finding can help in the development of fusion energy, a reaction that powers the Sun and other stars. In this process, two light nuclei merge to form a single heavier nucleus. The process releases energy because the total mass of the resulting single nucleus is less than the mass of the two original nuclei. The leftover mass becomes energy.

Fusion can involve many different elements in the periodic table. However, researchers working on fusion energy applications are particularly interested in deuterium-tritium (DT) fusion. Notably, DT fusion produces a neutron and a helium nucleus.

It also releases much more energy than most fusion. In a potential future fusion power plant such as a tokamak or stellarator, neutrons from DT reactions would generate power for our use. Researchers focus on DT reactions both because they produce large amounts of energy and they occur at lower temperatures than other elements, according to US DOE.