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Tokamak Reactors: Harnessing the Power of the Sun
The Tokamak Reactor, is a magnetic containment device that is one of the most researched methods for controlled thermonuclear fusion power. The initial design was first theorized by Russian physicist Oleg Lavrentiev in the 1950s, but it wasn’t until a few years later that two Russian physicists — Igor Tamm and Andrei Sakharov — invented what we now know as a Tokamak.
A Tokamak of today uses electromagnetism to confine plasma within the reactor, keeping it from actually touching the walls of the reactor. Not only is the torus shape of the Tokamak crucial in achieving the proper plasma equilibrium, but it also allows the magnetic field lines inside the torus to be manipulated in a helical shape, and this shape is created by combining a toroidal and poloidal magnetic field.
Electromagnets surrounding the torus create a toroidal field. A toroidal field is a magnetic field traveling in circles around the torus. Similarly, electromagnets are used inside the torus to induce the poloidal field (it is generated by the electrical flow of plasma); this poloidal field travels in circles orthogonal to the toroidal field, resulting in the required helical shape.
Due to limited advances in technology, the biggest issue that has always held back the Tokamak reactor is the problem of heating the plasma. In order for the plasma to reach its operating temperature, it must be heated to approximately 100 million degrees Celsius. Various different methods are used to heat the plasma, which range from using magnetic compression to bombarding the plasma with high-frequency microwaves.
The Tokamak creates energy by absorbing large amounts of high energy neutrons. These neutrons are created by the heated plasma spinning around the reactor. Because these neutrons are neutrally charged, they are no longer held in the plasma stream by the magnetic fields, and continue outwards until they are stopped by the inner walls of the reactor. The heat from these neutrons is then converted into energy; however, a lot is lost in the process due to cooling.

The neutrons yield so much energy, they could actually melt the walls of the reactor, which is obviously not good. So to prevent this from occurring and destroying the system, a cryogenic cooling system is needed. Such a system utilizes a mixture of liquid helium and liquid hydrogen. When combined with ceramic plates, they protect the superconducting magnets and reactor walls. There are currently around 30 known Tokamak reactors in operation around the globe; the majority of them scattered across Europe, Russia and China.
Currently the largest Tokamak reactor, ITER, is being constructed in France. As the name suggests, it is an international joint program between the European Union, India, Japan, China, Russia, South Korea and the United States.
ITER’s mission is to demonstrate the feasibility of a fusion reactor and to show that it can operate without negative impact to the environment or to surrounding ecosystems.
In May 2021, the experimental hybrid thermonuclear reactor Tokamak T-15MD, which is part of the international thermonuclear project ITER, was launched at the Kurchatov Institute in Russia. The institute claims that the T-15MD has no analogues in the world.

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