A new, lower-cost path to fusion energy has opened up with the materialization of high-temperature superconductors that are functional at high magnetic fields.
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This discovery is particularly big huge when it comes to future fusion research.
Tokamak is the most developed device so far which uses strong magnetic field to keep plasma away from the walls and the device is in the shape of a torus.
In fusion reactor designs, superconductors (which suffer no resistive power loss) are used to generate the magnetic fields that confine the 100 million degree C plasma. Its intensity is what determines the confinement state of the magnetic island.
Scientists have found a new captivity & confinement state for plasma which would very form the future of fusion energy. For that reason turbulence generated outside the magnetic island where a temperature gradient exists enters into the magnetic island, and the confinement state inside the magnetic island will be determined depending upon the intensity of turbulence. The “momentary heating propagation method” allows the plasma confinement performance (adiabaticity) to be diagnosed from the amplitude of temperature variations and the propagation speed caused by the momentary heating.
This innovative approach was detailed in a recent edition of Scientific Reports, a prestigious periodical of the British science journal Nature group.
Reseachers from the United States and China led by Andrea Garofalo from General Atomics, California and Xianzu Gong from the Institute of Plasma Physics Chinese Academy Of Sciences, China, are now in the process of developing this facility that will hold a 500 megawatt ITER fusion research center in France as this will become a joint project that involves 35 nations.
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In this particular study, scientists were able to discovery for the first time ever a new confinement state within one of these magnetic islands, which could lead to better confinement methods that would be used in a hypothetical fusion reactor. Previously, experiments in LHD found “that confinement performance inside the magnetic island is good (the adiabaticity was 7 times greater than outside)”. In this new study, the worldwide Thermonuclear Experimental Reactor is now working on a project that aims to design and develop an experimental reactor based on this Tokamak concept. If turbulence outside rises because of temperature gradients, the turbulence moves to the islands eventually. Improving confinement states for magnetic islands is the key to fusion plasma’s future. “Thus, research on turbulence in magnetic islands is an extremely important topic”. The research team has registered success in initial phases of the “high-bootstrap current” scenario, which enhances self-generated (“bootstrap”) electrical current to find an optimal tokamak configuration for fusion energy production. The experiment resulted in stable flowing plasma under high pressure that maintained its confined state. The gambit paid off. Moving the plasma closer to the wall removed the kink mode and enabled higher plasma pressure, which, in turn, makes the plasma less dependent on externally injected flow. “The chief operator said ‘You can’t do that anymore, you’re going to damage the machine, ‘ so it was a struggle to prove our theory was correct”, said Garofalo. This is important because in a tokamak reactor, such as ITER, it is very hard and expensive to drive a rapid plasma flow with external means.
