How does it work

When it comes to promising forms of energy, nuclear fusion ticks all the boxes: clean, affordable, continuous and safe. When the light nuclei of two atoms fuse together to form a heavier nucleus, a huge amount of energy is released.

For the fusion reaction to occur in a controlled manner, reactors are needed, which are large loops filled with magnets to create magnetic fields in which atomic particles “dance” around like a swarm of bees.

The EPFL lab specializes in this realistic 3D visualization technology. It has developed a program that transforms terabytes of data from tokamak simulations and tests conducted by the Swiss Plasma Center into stunning 3D visualizations.

For the general public, visualization is a journey through a ring of fireworks that shows a possible future energy source. For scientists, it is a valuable tool that makes the complex phenomena of quantum physics tangible and helps them understand the results of their calculations.

Very accurate images

In this case, the 3D visualization is a panorama measuring 4 meters high and 10 meters in diameter. It is an exact replica of the interior of a real tokamak, and is rendered in such striking detail that it is not inferior to even the highest quality gaming experience.

We used a robot to perform a high-precision scan of the reactor’s interior, which we then compiled to create a 3D model that reproduces its components down to the texture.
– says computer scientist Sami Mannane.

Scientists were even able to record the corrosion of graphite tiles lining the reactor walls, which were exposed to extremely high temperatures during the reactor’s test runs.

Engineers then provided equations to calculate the precise motion of quantum particles at a given moment. The researchers then combined these equations with reactor data and fed it into a 3D visualization system. The challenge is all calculations must be done in real time. To create a single image, the system must calculate the trajectories of thousands of moving particles 60 times per second for each eye. These heavy calculations are performed by five computers, each with two GPUs. The computer output is fed to five 4K panorama projectors.

“We were able to create our system thanks to the development of infographic technologies. Five years ago this would have been impossible,” says Professor Sarah Kenderdin.

The result is stunningly realistic images. You can see the injector device that injects particles into the tokamak, as well as graphite tiles that can withstand temperatures of over 100 million degrees Celsius.

Visualization of the processes taking place inside a thermonuclear reactor / Photo EPFL / Experimental Museology Laboratory (EM+)

Visualization of the processes taking place inside a thermonuclear reactor / Photo EPFL / Experimental Museology Laboratory (EM+)

The scale of it all is incredible. To help viewers understand, the visualization includes an image of a person, showing the reactor to be about twice their size. As the simulation zooms in, the viewer feels very small as thousands of particles fly past them, spinning, whirling, and chasing each other.

Electrons are marked in red, protons in green, and blue lines indicate the magnetic field. Users can adjust any of the parameters to see a specific section of the reactor from a selected angle with a near-perfect visualization.

Visualization of the processes taking place inside a thermonuclear reactor from a different perspective / Photo EPFL / Experimental Museology Laboratory (EM+)

The biggest challenge, the scientists say, is “to extract concrete information from such a large database to create an accurate, consistent, and real visualization, even if it is virtual.” The physics behind the visualization process is extremely complex.

Tokamaks have many different moving parts: particles with heterogeneous behavior, magnetic fields, waves to heat the plasma, externally injected particles, gases, and more. Even physicists have a hard time understanding it all. The rendering combines standard output from simulation programs with real-time rendering techniques that the lab uses to create a video game-like atmosphere.