5 tonnes of Silver used for 1 Thermal Shield
to protect the tokamak's superconducting coils from thermal radiation, it is coated with the most efficient of "low-emissivity" materials. And this material happens to be silver.
The vacuum vessel thermal shield comprises nine 40° sectors. Sector #6 is pictured here, ready to be packed and shipped to ITER
From Iter Newsline #3272
“Because its mission is to protect the tokamak's superconducting coils from thermal radiation, it is coated with the most efficient of "low-emissivity" materials. And this material happens to be ... silver.
Given the size of the thermal shield (approximately 2,000 square metres), a 5- to 10-micrometre-thick silver plating on both sides requires no less than 5 tonnes¹ of the precious metal—enough to make 625,000 sterling silver rings.
A first finalized sector of the vacuum vessel thermal shield (sector #6) has left the SFA Engineering Corp in Changwon, Korea, to be delivered to ITER.
¹Five tonnes of silver will be required in the electroplating baths. The mass of silver coating the thermal shield panels is estimated at just under 800 kg total.
Source - https://www.iter.org/newsline/-/3272
What is ITER?
In southern France, 35 nations* are collaborating to build the world's largest tokamak, a magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy based on the same principle that powers our Sun and stars.
The experimental campaign that will be carried out at ITER is crucial to advancing fusion science and preparing the way for the fusion power plants of tomorrow.
The primary objective of ITER is the investigation and demonstration of burning plasmas—plasmas in which the energy of the helium nuclei produced by the fusion reactions is enough to maintain the temperature of the plasma, thereby reducing or eliminating the need for external heating. ITER will also test the availability and integration of technologies essential for a fusion reactor (such as superconducting magnets, remote maintenance, and systems to exhaust power from the plasma) and the validity of tritium breeding module concepts that would lead in a future reactor to tritium self-sufficiency.
What is TOKAMAK?
Power plants today rely either on fossil fuels, nuclear fission, or renewable sources like wind or water. Whatever the energy source, the plants generate electricity by converting mechanical power, such as the rotation of a turbine, into electrical power. In a coal-fired steam station, the combustion of coal turns water into steam and the steam in turn drives turbine generators to produce electricity.
The tokamak is an experimental machine designed to harness the energy of fusion. Inside a tokamak, the energy produced through the fusion of atoms is absorbed as heat in the walls of the vessel. Just like a conventional power plant, a fusion power plant will use this heat to produce steam and then electricity by way of turbines and generators.
The heart of a tokamak is its doughnut-shaped vacuum chamber. Inside, under the influence of extreme heat and pressure, gaseous hydrogen fuel becomes a plasma—the very environment in which hydrogen atoms can be brought to fuse and yield energy. (You can read more on this particular state of matter here.) The charged particles of the plasma can be shaped and controlled by the massive magnetic coils placed around the vessel; physicists use this important property to confine the hot plasma away from the vessel walls. The term "tokamak" comes to us from a Russian acronym that stands for "toroidal chamber with magnetic coils."
First developed by Soviet research in the late 1950s, the tokamak has been adopted around the world as the most promising configuration of magnetic fusion device. ITER will be the world's largest tokamak—twice the size of the largest machine currently in operation, with ten times the plasma chamber volume.
source - https://www.iter.org/proj/inafewlines
We ran keywords through ChatGPT
A tokamak is a type of magnetic confinement device used in the field of nuclear fusion research. It is designed to create and contain a high-temperature plasma, which is the hot, ionized gas that fuels nuclear fusion reactions, similar to those that power the sun and other stars. The ultimate goal of tokamak research is to develop a practical and sustainable source of energy through controlled nuclear fusion.
Here are some key details about tokamaks as magnetic fusion devices and potential sources of energy:
Basic Principle: The word "tokamak" is derived from the Russian acronym for "toroidalnaya kamera s magnitnymi katushkami" or "toroidal chamber with magnetic coils." The tokamak's basic principle involves using a combination of toroidal (doughnut-shaped) and poloidal (vertical) magnetic fields to confine and stabilize the high-temperature plasma.
Plasma Formation: In a tokamak, a low-density, high-temperature plasma is created by heating a fuel mixture of isotopes of hydrogen, typically deuterium and tritium. These isotopes are chosen because they can readily undergo fusion reactions at the temperatures achievable in a tokamak.
Magnetic Confinement: The magnetic fields in a tokamak are generated by a series of coils that surround the plasma. The toroidal magnetic field helps to confine the plasma in a circular path, while the poloidal magnetic field prevents the plasma from drifting out of the containment chamber. This combination of fields is what gives the plasma its characteristic toroidal shape.
Plasma Stability: Achieving and maintaining plasma stability is a significant challenge in tokamak design. Instabilities can disrupt the plasma and hinder fusion reactions. Various techniques, such as careful shaping of the magnetic fields and feedback control systems, are employed to control and stabilize the plasma.
Heating Methods: Several methods are used to heat the plasma to the required temperatures (tens of millions of degrees Celsius). These methods include ohmic heating (using the plasma's electrical resistance to generate heat), neutral beam injection, and radiofrequency (RF) heating.
Fusion Reactions: When the plasma reaches the necessary temperature and density, deuterium and tritium nuclei can collide and fuse, releasing energy in the form of high-energy neutrons. This energy can be captured and used for power generation.
Neutron Activation: One of the challenges of tokamak-based fusion is dealing with the high-energy neutrons produced during fusion reactions. These neutrons can activate the surrounding materials, making them radioactive. Research is ongoing to develop materials that can withstand this neutron bombardment and have manageable radioactive waste.
ITER: The International Thermonuclear Experimental Reactor (ITER) is one of the most prominent tokamak projects in the world. It is an international collaboration aimed at demonstrating the feasibility of nuclear fusion as a large-scale and carbon-free source of energy. ITER is being constructed in France and is expected to be operational in the coming years.
Energy Potential: Nuclear fusion has the potential to provide a nearly limitless and clean source of energy. It produces minimal greenhouse gas emissions, and its fuel sources (deuterium and lithium) are widely available. If successfully harnessed, fusion could help address the world's energy needs while mitigating climate change.
Challenges: Despite significant progress, there are still numerous technical challenges to overcome before practical fusion power plants can be built. These challenges include achieving sustained plasma confinement, managing the intense heat and radiation, and developing efficient methods for extracting energy from the fusion reactions.
In summary, tokamaks are a promising technology for achieving controlled nuclear fusion, which has the potential to revolutionize the energy industry by providing a safe, clean, and virtually limitless source of power. While significant progress has been made, it will likely be several more years before fusion power plants become a reality.
We ran keywords through google AI Bard
A tokamak is a device which uses a powerful magnetic field to confine plasma in the shape of a torus. The tokamak is one of several types of magnetic confinement devices being developed to produce controlled thermonuclear fusion power. As of 2016, it was the leading candidate for a practical fusion reactor.
The name "tokamak" is a Russian acronym for "toroidal chamber with magnetic confinement". The first tokamaks were built in the Soviet Union in the 1950s and 1960s. The first tokamak to achieve sustained fusion plasma was the T-3 tokamak, built in the Soviet Union in 1968.
The basic principle of a tokamak is to use a strong magnetic field to confine a plasma in the shape of a torus. The plasma is heated to very high temperatures, typically millions of degrees Celsius. At these temperatures, the atoms in the plasma are ionized, meaning that they have lost their electrons. The ionized atoms are then free to move around, and they can collide with each other. When two ionized atoms collide, they can fuse together, releasing a large amount of energy.
The magnetic field in a tokamak is created by a series of coils that are arranged around the torus. The coils are powered by electricity, and they create a magnetic field that is strong enough to confine the plasma. The magnetic field also helps to prevent the plasma from touching the walls of the tokamak.
The tokamak is a very complex device, and there are many challenges that need to be overcome before it can be used to produce commercial fusion power. One of the biggest challenges is to create a magnetic field that is strong enough to confine the plasma without touching the walls of the tokamak. Another challenge is to heat the plasma to the temperatures that are necessary for fusion.
Despite the challenges, the tokamak is the leading candidate for a practical fusion reactor. The ITER tokamak, which is currently under construction in France, is expected to be the first tokamak to produce net energy from fusion. If ITER is successful, it will pave the way for the development of commercial fusion reactors.
Here are some of the advantages of tokamaks:
They are relatively easy to build and maintain.
They can be scaled up to produce large amounts of power.
They are relatively efficient at converting heat into electricity.
Here are some of the challenges of tokamaks:
They require very strong magnetic fields.
They are susceptible to instabilities that can disrupt the plasma.
They are difficult to operate in a sustained manner.
Despite the challenges, tokamaks are the leading candidate for a practical fusion reactor. The ITER tokamak, which is currently under construction in France, is expected to be the first tokamak to produce net energy from fusion. If ITER is successful, it will pave the way for the development of commercial fusion reactors.