Production of key components ITER has begun.

Thermonuclear reactor ITER - a small copy of the Sun

After several years of delays , work has finally begun on assembling the key components of ITER - the toroidal field coils.

One of the largest components of a fusion reactor is made by the contractor CNIM. He was engaged in shipbuilding before he switched to precision engineering. The location of the plant in La Seyne-sur-Mer in the suburb of Toulon (France) on the coast is an advantage, because some of the components are so cumbersome that they can only be transported by sea.

In one of the workshops, a giant drill pierces channels in D-shaped steel hinges about 20 meters in size. They are made of extremely durable steel, so that carbide drills have to be changed every 8 minutes.
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Seven such loops are attached to each other to form one of the many magnets controlling the plasma at a temperature of 10 million ° C in a vacuum chamber.


ITER reactor layout: reactor overall dimensions ~ 40 x 40 meters; 1 - central solenoid (inductor); 2 - poloidal magnetic field coils; 3 - toroidal magnetic field coil; 4 - vacuum chamber; 5 - cryostat; 6 - diverter
^{Here and below - illustrations from the official booklet “International ITER Project” of the Corporation “Rosatom”}

However, this is still far away. First you need to ship the loop to the plant in the city of La Spezia in northern Italy, where another contractor will introduce up to 700 meters of superconducting cable into each of them. Then they will be transported to Venice, where another Simic company will complete the assembly of the finished toroidal coils. Each coil will weigh as a fully loaded Boeing 747. Simic is also involved in the production of other loops, so they have to make a circular journey to La Spezia and back. ITER management initially chose such a strategy, when contractors fight for contracts, and different parts of the same site are sometimes produced on different continents.

The finished reels are transported to the French port, where 800 tons are loaded onto a 352-wheel transporter. He slowly pulls the load to the construction site ITER 104 km from the coast. If everything goes according to plan, the first coils will be delivered to the place of the future thermonuclear reactor in three years.



And this is only a tiny part of the work that remains to be done before launching ITER.

ITER refers to thermonuclear tokamak reactors, a toroidal installation for magnetic plasma confinement in order to achieve the conditions necessary for the flow of controlled thermonuclear fusion. In the vacuum chamber, the nuclei of deuterium and tritium merge to form a helium nucleus (alpha particle) and a high-energy neutron. The plasma in the tokamak is not held by the chamber walls, but by the combined magnetic field — the toroidal external and poloidal field of the current.



Russia, the United States, the European Union, China and other countries are taking part in an ambitious international project. The thermonuclear reactor proposed by Soviet physicists in 1985 was agreed at a meeting of presidents Reagan and Gorbachev. Since then, the preparation and design has been going on, in 2001 a technical design was prepared, and in 2005 the participating countries decided on the construction site - the neighborhood of the city of Cadarache in southern France.

ITER - the most difficult technical structure in the history of mankind. The main structure consists of 10 million parts. This is more than in the Large Hadron Collider. Engineers call it a “puzzle of 10 million pieces.” Not surprisingly, the preparation took so long.


Playground ITER

At least, the progress in the manufacture of toroidal field coils seems more significant than in the manufacture of another key component - the poloidal field coils. A special building has been built for their production, which is almost empty for now, not counting several drawers and a circular crane hanging from the roof: since 2012, almost nothing has changed.

Unfortunately, the deadline for the first run of the working plasma has recently been shifted again. The project director calls the year 2023, independent experts are inclined to the 2025th. After a trial run, approximately four years of testing will follow, before a real mixture of deuterium and tritium is loaded into the chamber. The task of ITER is to demonstrate a controlled fusion reaction with a thermonuclear power of several hundred megawatts and the development of its practical use technology. After that, you can build the same installation around the world.

At the first stage, the reactor will operate in a pulsed mode with a thermonuclear reaction power of 400–500 MW and a pulse duration of about 400 s. At the second stage, the continuous operation mode of the reactor will be tested, as well as the tritium reproduction system.

Scientists are unanimous in their opinion that behind the thermonuclear is the future of energy. Stocks of deuterium in the water of the oceans are inexhaustible, the lithium content in the earth's crust is 200 times more than uranium (lithium is used to obtain tritium directly on ITER). There are other advantages: the radiation biohazard of thermonuclear reactors is about a thousand times lower than that of fission reactors; the possibility of placing the reactor in any place; the absence of "heavy" radioactive waste that can be used to make "dirty" bombs; physical impossibility of acceleration ("explosion") of the reactor.