Soon after tapping power from nuclear fission, Scientist turned their interest towards its mightier twin, Nuclear fusion. The ambitious minds of the 20th Century wanted to tap to the power of the mighty sun. But to reach such technology to contain such powerful energy in a controlled way and reach such high temperatures to make fusion possible was a humongous task. Engineers all over the World have been formulating many Engineering models over the past few decades and yet we are still decades away from tapping this power.
Among these, one of the most promising mega machines is the Tokamak. The idea was developed in the mid-1960s by Soviet Union Plasma Physicists. It’s based on the idea of confining plasma to extremely high pressure, density and Temperature creating conditions for fusion to take place. It has been successful in producing the highest plasma temperatures and densities for fairly long periods of time. It uses the physics of magnetic confinement of Charged particles and uses strong Electromagnets to create a toroidal magnetic field.
As for the processing, first the chamber of the tokamak is evacuated and a vacuum state is obtained, then the Magnets which are to confine the plasma are charged up and finally the hot gaseous fuel is introduced . As ion injection takes place, the gas breaks down electrically, becomes ionized and forms plasma. As the plasma particles become energized and collide, they heat up and reach temperatures between 150-300 million degree Celsius.The temperatures inside the Tokamak must reach 150 million °C or ten times the temperature at the core of the Sun, in order for the gas in the vacuum chamber to reach the plasma state and for fusion to occur.
They use neutral beam injection and ion oscillation using radio waves to reach such thermal conditions allowing fusion prone environment. Particles in this state tend to overcome the Electro-magnetic barrier and undergo fusion, releasing huge amounts of heat energy which can be extracted using pressurised water as a coolant. The heated water is used to produce steam, which is then passed over a turbine to generate electricity. The Fuel selected for use in controlled fusion reactors is generally a mixture of deuterium and tritium.
The world’s largest Tokamak is being developed by ITER in France which is about twice the size of the presently operating one and has 10 times the plasma chamber volume. It would be completed by 2024 and operational by 2035. It aims in understanding the properties of matter during operation of the tokamak and in future hopes to commercialize fusion to produce green carbon-free Nuclear Energy.
Unlike fission, fusion produces very less radioactive waste that becomes harmless within the next 100 years (As getting rid of nuclear waste is the only disadvantage of Nuclear Energy). Thus with the advancement of Science and Technology we hope to establish working Fusion Plants and tap to an unlimited source of green energy.
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