Plans postponed

The International Thermonuclear Energy Project (ITER) fusion reactor, which consists of 19 large coils wrapped around multiple toroidal magnets, was scheduled to begin its first full test in 2020. Now scientists say it is Will be operational before 2039.

This means that thermonuclear energy, of which the ITER tokamak is a leading power, is unlikely to solve the climate crisis in time.

The world’s largest nuclear reactor is the product of cooperation between 35 countries, including all countries of the European Union, England, China, India and the USA. ITER contains the world’s most powerful magnetIn this way, it can create a magnetic field 280,000 times stronger than the magnetic field that protects the Earth.

The impressive design of the reactor is matched by an equally impressive price tag. The reactor was originally planned to cost around $5 billion and be operational in 2020, but has now suffered multiple delays and is over budget by over $22 billion, with another $5 billion proposed to cover additional costs. These unforeseen costs and delays have led to the latest 15-year delay.

Thermonuclear fusion

Scientists have been trying to harness the power of nuclear fusion—the process that makes stars burn—for more than 70 years. Stars combine hydrogen atoms to produce helium at extremely high pressures and temperatures, generating vast amounts of energy without producing greenhouse gases or long-lived radioactive waste. But recreating the conditions at the heart of a star is no easy task on Earth.

The most common fusion reactor design, the tokamak, works by superheating plasma (one of the four states of matter composed of positive ions and negatively charged free electrons) before confining it within a doughnut-shaped reactor chamber with strong magnetic fields.

However, it is very difficult to keep coils of plasma in place that are turbulent and superheated enough for nuclear fusion to occur. No one has yet succeeded in creating a reactor that can give off more energy than it absorbs.The only exception was an experiment in which scientists were able to exceed this threshold for a few seconds, but this is of course not enough.

What’s the problem

One of the biggest hurdles is working with plasma hot enough for fusion. The thing is, the synthesis process itself requires certain conditions that are present in stars. When a star reaches a sufficient mass, it glows and starts to heat up. For example, if Jupiter were a little more massive, it would turn into a brown dwarf (where thermonuclear reactions do not occur, but they are already heated and glow). And if it gains even more mass, it can turn into a full-fledged star. So reaction requires pressure and temperature.

Fortunately, one can replace the other, but you have to change the ratios. If we can’t maintain enough pressure on Earth, we have to compensate with a higher temperature. And that’s The temperature must be higher than that at the star’s core..

The Sun’s core reaches temperatures of about 15 million degrees Celsius, and has pressures about 340 billion times greater than air pressure at sea level on Earth. Heating plasma to these temperatures is relatively easy with modern technology, but finding a way to contain it without blowing up the reactor and disrupting the fusion reaction is not a technically easy task.

Scientists are now looking for new reactor designs to overcome this problem. For example, a protective sheath made of tungsten has outperformed other materials. This probably won’t be the last discovery in this area, so we’ll see other alloys that provide better protection against high temperatures for reactors in the future.