How Do Tokamaks Work To Make Nuclear Fusion Possible?, Pg13

Key Highlights:

• A tokamak is a device that uses magnetic fields to confine extremely hot plasma in a ring-shaped vacuum chamber to achieve nuclear fusion.
• It addresses the "containment problem" for fusion, as no physical material can withstand the temperatures required, which are hotter than the sun's core.
• The concept was developed in the early 1950s in the Soviet Union, primarily by physicists Igor Tamm and Andrei Sakharov.
• The International Thermonuclear Experimental Reactor (ITER), a collaborative global project, is a tokamak currently under construction in France.
• India operates its own tokamaks, ADITYA-U and SST-1, at the Institute for Plasma Research (IPR) in Gandhinagar and is a key contributor to ITER.
• China's EAST tokamak has set records for plasma confinement duration and density but has not yet generated net energy.

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Detailed Insights:

• Nuclear fusion involves light atomic nuclei, such as deuterium and tritium, combining to form helium, releasing a substantial amount of energy.
• The tokamak's unique toroidal shape and an electric current driven through the plasma create a helical magnetic field, effectively isolating the plasma from the chamber walls.
• In a future fusion power plant, neutrons from the reaction would heat a surrounding blanket containing lithium, generating steam for electricity and breeding tritium fuel.
• The ITER project has faced considerable engineering challenges, funding delays, and cost escalations, with research operations now projected for 2034 and deuterium-tritium operations for 2039.
• ITER is primarily a physics experiment designed to demonstrate net energy gain (producing ten times the heating power input), not to directly convert heat into electricity.
• Other approaches to fusion research include stellarators, which use complex external coils to create the twisted magnetic field, and inertial confinement, which compresses fuel pellets with lasers.
• The U.S. National Ignition Facility successfully demonstrated "net energy" production using the inertial confinement approach in 2022.

Scientific/Technical Concepts Involved:

• Tokamak: A toroidal device that uses magnetic fields to confine plasma for controlled nuclear fusion reactions.
• Plasma: The fourth state of matter, an ionized gas consisting of free electrons and atomic nuclei.
• Nuclear Fusion: A process where two light atomic nuclei combine to form a single heavier nucleus, releasing a large amount of energy.
• Deuterium & Tritium: Heavy isotopes of hydrogen that are the primary fuel candidates for nuclear fusion reactors.
• Magnetic Confinement: A method of containing superheated plasma using strong magnetic fields to prevent it from touching reactor walls.