Now a team from the Massachusetts Institute of Technology (MIT) thinks we might finally have a reason to get excited, although we should still err on the side of cautious optimism. Using a new type of superconductor, they say they can reduce the size of a potential fusion reactor while drastically increasing its power output. “It changes the whole thing,” Dennis Whyte, a professor of Nuclear Science and Engineering and director of MIT’s Plasma Science and Fusion Center, said in a statement. Quite.

Their proposal involves a type of reactor known as a tokamak, which is donut-shaped. A fusion reactor recreates the Sun’s process of fusing hydrogen atoms together to form helium at its core, which releases enormous amounts of energy. One of the hardest parts of replicating this, though, is heating the plasma required for the reaction to temperatures equivalent to the core of a star, about 15 million degrees Celsius (27 million degrees Fahrenheit), while keeping it confined.

Doing so has relied on using magnetic fields produced by copper conductors to trap the heat and particles in the center of a reactor, but producing strong enough magnetic fields via this method is a complicated, not to mention bulky, process.

So, what if there was another way?

In their paper in Fusion Engineering and Design, the MIT team explain that by using rare-earth barium copper oxide (REBCO) superconducting tapes instead of copper, high-magnetic field coils can be created at a fraction of the size. In fact, they say they could actually increase the fusion power by a factor of 10 in their experimental reactor, nicknamed ARC (hat tip to Iron Man), when it is cooled to the temperature of liquid nitrogen, about -200°C (-330°F). This is because the new superconductors produce a stronger field than their copper counterparts.

“The much higher magnetic field allows you to achieve much higher performance,” said Ph.D. candidate Brandon Sorbom from MIT in a statement.

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> Their proposal involves a type of reactor known as a tokamak, which is donut-shaped.

That’s a good start.

> Doing so has relied on using magnetic fields produced by copper conductors.

I see the problem. You couldn’t do that on the LHC and get away with it.

> using rare-earth barium copper oxide (REBCO) superconducting tapes instead of copper …

Excellent. Just beware of the fact that if the magnetic field increases too much then the superconductivity is lost. But I’m sure they’ve taken that into consideration.

Spiny Norman said:

In their paper in Fusion Engineering and Design, the MIT team explain that by using rare-earth barium copper oxide (REBCO) superconducting tapes instead of copper, high-magnetic field coils can be created at a fraction of the size. In fact, they say they could actually increase the fusion power by a factor of 10 in their experimental reactor, nicknamed ARC (hat tip to Iron Man), when it is cooled to the temperature of liquid nitrogen, about -200°C (-330°F). This is because the new superconductors produce a stronger field than their copper counterparts.

Oh wait. Is this already being done?

1) “The Experimental Advanced Superconducting Tokamak (EAST, internal designation HT-7U) is an experimental superconducting tokamak at the Chinese Academy of Sciences”. “EAST will test superconducting NbTi poloidal field magnets, making it the first tokamak with superconducting toroidal and poloidal magnets”. Switched on in 2006.

2) “China’s first superconducting tokamak device, dubbed HT-7, built in partnership with Russia in the early 1990s.”

3) “SST-1 (steady state superconducting tokamak) is a plasma confinement experimental device in the Institute for Plasma Research (IPR), an autonomous research institute under Department of Atomic Energy, India.” Started in 2005. Restarted after a rebuild in 2012.

4) Among superconducting tokamaks, Tore Supra in France was the first to test niobium-titanium in its toroidal field system in 1988.

5) Niobium-tin (Nb3Sn) superconducting magnets were integrated in the Korean tokamak KSTAR (2008)

6) JT-60 (JT stands for Japan Torus) is the flagship of Japan’s magnetic fusion program. In 2010 JT-60 is being disassembled to be upgraded to JT-60SA by using niobium-titanium superconducting coils. This was underway in 2010 and will continue until at least 2016.

So that makes five tokamaks around the world already using superconducting magnets, and one that soon will.

These six use low temperature superconductors. The proposed copper-oxide design is a high temperature superconductor, not necessarily as good, but worth trying out as a magnet.

Reading the various articles on fusion power and the massive amount of infrastructure/complexity required you understand why it’s taken so long just to get test facilities up and running, let alone an actual commercial working model being available. It seems to make fission power facilities seem simple in comparison and its only in recent times our technology is capable of creating such facilties