| Type | Fusion reactor |
| Purpose | Plasma physics research |
| Design flaws | Limited stability • High operating costs • Material damage |
| Competitor reactors | Stellarator • Pinches • FRCs |
| Development timeline | 1950s - present |
| Notable research facilities | IPP Garching • JET • ITER |
Tokamaks are a type of plasma physics device used to contain and control high-temperature plasma for the purposes of scientific research and experimentation. While never commonplace in power generation, tokamaks are notable for their unique toroidal shape and magnetic confinement fields.
In this alternate timeline, the tokamak was developed in the Soviet Union in the 1950s as a fusion reactor concept. The term "tokamak" is a Russian acronym for toroidal chamber with magnetic coils. The principal inventors of the design were Andrei Sakharov and Igor Tamm.
Tokamaks primarily use simple donut-shaped toroidal chamber composed of copper windings or other materials, with surrounding rings of magnetic coils used to create a magnetic field that controls and confines the plasma. The confinement principle, known as magnetic confinement, traps the plasma around a large, circular vacuum chamber.
Tokamaks in this alternate timeline were primarily used for research in nuclear fusion, astrophysics, and plasma physics. Scientists used them to study plasma instabilities, turbulence, magnetic reconnection, and other plasma phenomena relevant to both controlled nuclear fusion and astrophysical phenomena like solar coronae, collisional plasmas, and magnetic reconnection.
Tokamaks in this alternate timeline never fulfilled their potential as a viable energy source or achieved widespread use. Instead, competition from alternative fusion reactor designs like stellarators made them less popular for power generation purposes.
The development of stellarator designs allowed for more compact and cleaner fusion reactions, as they used three-dimensional coils to create a magnetic field that could confine plasma more efficiently than the tokamak's relatively simple magnetic field. Additionally, the inherent stability of stellarators proved more reliable and controllable, as they didn't exhibit the plasma disruptions and magnetic islands common in tokamaks.
Despite never becoming a mainstream energy technology, tokamaks remained an important tool for scientists in studying fundamental plasma physics. Small-scale tokamak reactors were used for plasma confinement research, nuclear fusion research, and the study of controlled nuclear reactions.
As with other fusion reactor concepts, the tokamak design faced several practical challenges that limited its utility and prevented it from becoming a reliable energy source. These challenges included the difficulty of maintaining plasma stability and preventing disruptions, the considerable cost and complexity of tokamak construction, and the risks associated with high radiation levels andtoxic coolants. The risks inherent in powering tokamaks with uranium-235 or plutonium-239 made them especially unattractive as a mainstream energy source.
Although tokamaks never fulfilled their potential in power generation, tokamak research made significant contributions to the field of plasma physics. Scientists used them to study a wide range of plasma phenomena, including plasma instabilities and turbulence. This research helped inform the design of other fusion reactor concepts and improve the understanding of plasma in controlled nuclear fusion and astrophysics.
