An example of the use of fusion in industrial form is the ITER (International Thermonuclear Experimental Reactor) project.
Located in Cadarache in the south of France, its construction began after the ITER agreement of 2006.
Location on the production
The ultimate objective would be to produce more energy than it consumes, in a sustainable and low-carbon way. Let’s take, for example, the burning of a tonne of coal from a power station. This would produce about 30 GJ of energy. On the other hand, a thermonuclear fusion plant for one tonne of mixing would produce the equivalent of burning 11 million tonnes of coal.
The difficulties of this project are enormous! First, all the electrons have to be dissociated from their nuclei by increasing the temperature up to 150 million degrees to obtain an ionized gas: plasma.
For fusion to occur, it is necessary to overcome the electromagnetic force that forces the atomic molecules to repel, so that the strong interaction can generate the fusion of the two atoms.
computer-generated imagery from outside the system
A major problem arises, that of the strength of the materials. Tokamak seems to be the technical solution found by ITER. It consists of confining with the help of magnets arranged in a circle, allowing to confine the temperature with the help of an electromagnetic field.
The vacuum chamber is a high vacuum environment. It provides an initial protection against neutron radiation, contributes to the stability of the plasma and acts as a first barrier to contain radiation.
To reach 150 million degrees, ITER uses neutrals injection (a method of pulling high-energy particles from the plasma) and high-frequency electromagnetic waves, which will complement the ohmic heating induced by a high-intensity current (in turn induced by variations in magnetic fields: magnets).
Schema on the lateral part of the system
The fusion of deuterium and tritium (D-T) will produce a helium nucleus, a neutron and energy. The helium core carries an electric charge. It will therefore be subjected to the magnetic fields of the tokamak and remain confined to the plasma.
However, a neutron which, not being electrically charged, will remain insensitive to magnetic fields. The neutrons will be absorbed by the walls of the Tokamak, transferring their energy to the walls as heat.
If the Sun has automatically mastered fusion for billions of years using the laws and the 4 fundamental interactions, we’re going to have to settle for two to which we can add the work of thousands of people who for a century have been striving to transform this energy of tomorrow into energy of today.
Written by Couranjou Pierre