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“Fusion is the process that takes place in the Sun. Simply put, you take hydrogen, heat and compress it to extreme conditions so that hydrogen nuclei come close enough to overcome their mutual repulsive forces and fuse into a helium nucleus. In doing so, a huge amount of energy is released— even more than in nuclear fission. It is cleaner, safer, and on Earth we have practically unlimited supplies of hydrogen, while the byproduct is harmless helium rather than tons of radioactive waste,” said Pavel Turjanica, head of the Electronics and Testing Team at the Faculty of Electrical Engineering, University of West Bohemia in Pilsen (FEL UWB), at the start of an interview on how technologies developed at the RICE research center can help solve the global energy future.

So why don’t we have fusion power plants yet, if fusion has such promising potential?

Because although the process has been experimentally demonstrated and physicists essentially have the physics worked out, it remains technologically extremely demanding. Thousands of engineering challenges must be solved for a power plant to operate reliably and at high output, unlike a laboratory experiment. On the Sun, gravity helps the process, so the temperature required is “only” about 15 million °C, whereas here on Earth we must heat hydrogen to hundreds of millions of degrees. And then plasma must be contained without touching the reactor walls. Magnetic fields have to hold it precisely, stably, and for long periods—not just a few seconds. This is complex, because of the extreme temperatures, radiation, mechanics, materials, and control systems involved. Everything has to operate with absolute precision. At the same time, from the very beginning there has been a strong emphasis on ensuring that the plant does not generate waste that would need to be stored for thousands of years as with nuclear fission plants. This means some solutions are either undesirable or impossible to use.

What exactly does a fusion reactor look like?

Most are based on the so-called tokamak principle. You can imagine it as a giant American donut—a toroidal chamber with a central cavity. Inside, a ring of extremely hot plasma is confined by a strong magnetic field at a safe distance from the walls. It is essentially a closed magnetic trap that must remain absolutely stable. If the plasma touches the walls, it cools and the reaction stops. There is no risk of an explosion; the reaction shuts down on its own before anything serious can happen. Today, the tokamak is the most advanced and best-proven technology for achieving controlled fusion. There are others, such as laser systems or stellarators. And of course, there are also projects promising investors fusion within two years—but those usually ignore the laws of physics. If you want to learn more about fusion and tokamaks, I recommend the lecture by Slavomír Entler from the Institute of Plasma Physics of the Czech Academy of Sciences, available on our YouTube channel. He is one of our top experts on fusion and can explain it wonderfully without requiring a degree in physics beforehand.

Is there a device in the world that already manages fusion in practice?

There are many such devices today, but you probably mean a power plant. Currently, ITER in France is under construction—the largest human project on the planet. It is designed to be the first device to produce an energy output comparable to a conventional power plant. But it will not yet feed electricity into the grid; it will serve as a research facility to test which materials, technologies, and methods are best suited for energy generation. It will be followed by the DEMO reactor, which should already operate as a full-fledged power plant.

So are we close to the point where fusion can be used in real-world energy production?

Essentially yes… ITER is scheduled to go online around 2034. DEMO could follow about 15 years later, around 2049. Despite the technological complexity, that is not far off—we will live to see it.

Back to Pilsen. How is the Faculty of Electrical Engineering at UWB involved?

Originally by chance—a colleague from the Academy of Sciences passed me a contact at the Institute of Plasma Physics and said: “Look, they’re interested in what you’re doing, go meet them.” So I did. It turned out that we had technologies not yet used in fusion, and I thought of ways to apply them. I connected with my colleague Jan Řeboun, and together we managed to build the first functional sensor based on copper printed on a ceramic substrate, the so-called TPC technology. Here, our industrial partner, the company Elceram, deserves great credit—without them, the sensors would have remained only on paper. We then presented the sensors on an international platform bringing together experts in tokamak magnetic diagnostics from around the world. They were well received, and suddenly doors opened for us, because existing sensors are too large or use LTCC technology based on silver, which activates and creates highly radioactive waste. But the road to a final sensor was, and still is, long.

What exactly do the sensors you are developing do?

They help determine the precise position of plasma inside the reactor. This is essential to prevent the plasma from touching the walls and collapsing. Their key feature is resilience to the extreme environment. They are exposed to immense temperatures and especially neutron radiation.

That sounds extremely challenging.

To put it into perspective—there is a unit called DPA, “displacement per atom,” which indicates how many times, on average, each atom in a material is struck by neutrons strongly enough to shift it from its position. DEMO expects up to 10 DPA—meaning that all atoms are displaced ten times. And our sensors still have to function. That is truly exceptional, and it is also very difficult and expensive to test. This is why the sensors spent six months directly inside the core of the LVR-15 experimental nuclear reactor at CV Řež, connected to a special measuring system. We collected an enormous amount of incredibly valuable data, which we will be analyzing for months to come.

That sounds like a unique solution. Have you succeeded internationally as well?

Yes. We obtained a patent for the sensors and are now part of the EUROfusion consortium, the main European organization for developing the DEMO fusion power plant. At present, our sensors are the number one choice there.

How important is this collaboration?

Very. We used to be more on the sidelines; now we are fully engaged. Thanks to cooperation with the Institute of Plasma Physics, we have also joined the Czech Fusion platform, and UWB has signed a direct cooperation agreement with ITER for other systems as well, such as plasma cleaning of mirrors for optical diagnostics. This is crucial—we are directly linked to European fusion energy development. And not only that: the sensors have already been tested in the JET tokamak in the UK, and there is interest in using them for the construction of smaller experimental reactors, such as DTT in Italy. Our work is having an international impact.

Ing. Pavel Turjanica, Ph.D.
Head of the Electronics and Testing Team at FEL UWB. An expert with long-standing experience from previous work in automotive electronics development. Today he specializes in technologies for fusion reactors but also works on wireless power transfer systems and the development of testing and control systems. He collaborates with international partners on technologies for ITER and DEMO reactor diagnostics, the Institute of Plasma Physics of the Czech Academy of Sciences, CV Řež, as well as projects with companies such as Siemens, ZAT, TES, Comat, and many others. He is a member of the Working Group on Fusion Energy at the Ministry of Industry and Trade.