Theoretical Background of ITER
New technologies often use devices and substances that are very different from what classical physics first revealed to scientists. The fourth, lesser known state of matter, is called plasma and consists of ions and free electrons. Plasma is a great electrical conductor (mainly because of the free electrons), while it is known gases like air are almost perfect insulators. Secondly, the interactions between ions and electrons are of electromagnetic nature while atoms in a gas interact by colliding with each other. These odd properties of plasma attract curious scientists. As a consequence, this state of matter is widely used in science these days and it represents the starting point of an ambitious project at ITER.
What Is ITER?
The fusion nuclear reactor in Cadarache, southern France, has a poetically name with a double meaning – it is an acronym from International Thermonuclear Experimental Reactor and the Latin term for “the way”. Special in structure as in name, ITER is the first project that promises net energy as a result of fusion reactions, which means it will produce more energy than that absorbed by the system’s operation. This extremely ambitious plan started in 2005, followed by the beginning of the ground support construction in 2010, and is set to work on the first plasma in December 2025. By 2035, it is said to reach its peak and begin deuterium-tritium operations.
How Will ITER Produce Energy?
Nuclear fusion is the reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and resultant subatomic particles (according to the conservation laws). This reaction can be endoenergetic (absorbing energy) or exoenergetic (releasing energy). For example, the energy released by hydrogen nuclei fusing into heavier helium nuclei fuels our Sun. To this day, no net energy fusion reaction can happen on Earth because of the tough conditions it requires: temperature on the order of 15,000,000 degrees Celsius and maintaining high plasma density for a sufficiently long time. This plasma is confined and controlled by strong magnetic fields produced by a Tokamak device.
The term Tokamak comes from the Russian acronym that stands for “toroidal chamber with magnetic coils”, as it was first developed in the late 1960s Soviet research labs. The heart of a Tokamak is a doughnut-shaped vacuum chamber filled with gaseous hydrogen that, under the influence of extreme conditions, becomes a plasma. The strong magnetic field that controls the electrons and the ions is created by massive coils placed around the vessel. The energy produced is absorbed by the vessel’s walls and transported outside of the device.
Goals of ITER
Scientists at ITER had a few goals in mind when they designed this project:
- Produce 10 times more energy than the input – meaning that spending 50 MW will result in 500 MW ready to use, efficiency more than 10 times bigger than the actual record.
- Using the high temperature and density plasma in high-tech research programs focusing on heating, control, diagnostics, cryogenics, and remote maintenance.
- Achieve self-sustainable reactions using internal heating.
- Test tritium breeding and, if successful, supply the world with this isotope.
- Control the plasma and the fusion reactions with minimal hazards to the environment.
Countries Involved In ITER
The ITER Members are China, the European Union, India, Japan, Korea, Russia, and the United States, but to ensure the project’s efficient progress, cooperation agreements have been signed with Australia, Canada, Kazakhstan, and Thailand, as well as with over 60 international organizations, national laboratories, and universities. Most of the members’ contributions are completed components, systems, or buildings.
With such members’ diversity, there is no doubt left that this project is one of the most promising international collaborations ever made, and by the looks of it, the initiative with the greatest results for humanity.
This article on ITER is a guest article by Ariana Vlad, senior at the International Computers High School of Bucharest, Romania, where she focuses on studying Physics and Mathematics.