The LDX Courtesy of the LDX team

It’s amazing no one thought of it before: nuclear fusion from a levitating tire-sized magnet surrounded by 10-million-degree plasma. But that’s exactly what a joint project between MIT and Columbia University are tinkering with over at MIT’s Plasma Science and Fusion Center on the MIT campus. Using a donut-shaped half-ton magnet made of superconducting wire coils, researchers there are replicating the magnetic fields of planets to manipulate super-heated gases in an experiment that could lead to a breakthrough in nuclear fusion based power.

Nuclear fusion, of course, is the same process that provides the sun with its seemingly endless supply of intense energy. Researchers have long thought fusion could provide a nearly limitless source of carbon-free electrical energy. But creating a working fusion reactor with a solid energy output has proven tricky, as forcing atoms to fuse together is no easy task.

The MIT project offers a unique alternative to the two existing approaches to nuclear fusion that dominate the field. Tokamaks attempt to manipulate atoms by surrounding a central plasma-filled chamber with magnets. In an inertial fusion reactor, high-powered lasers bombard a fuel pellet in the center of the device to set a fusion reaction in motion. But neither approach has been able to achieve the kind of controlled, sustainable fusion reaction that would be useful for clean, dependable power generation.

The MIT project took a big step closer to making that happen with an experiment known as the Levitated Dipole Experiment (LDX). The round magnet was placed inside a 16-foot-diameter enclosure and suspended by a strong electromagnetic field. The magnet was then used to manipulate the superheated electrically charged gas – or plasma – contained within the enclosure.

It had previously been observed that plasmas in space become more densely concentrated when they interact with planets’ magnetic fields, so the magnet produced similar magnetic fields within the experiment. The result: random turbulence caused the plasma to become denser – a critical step to coaxing atoms into fusing together. This was the first time such results had been recreated in a laboratory.

Naturally, a whole lot more research has to go into this kind of technology, and scaling such a device to a commercially operable size would be something of a feat – precision levitating magnets and multi-million-degree plasma aren’t easy things to come by. But the findings do open a potential path to fusion as-yet unexplored, and since it doesn’t appear that mankind is going to quit gluttonously consuming energy anytime soon, any clean energy we can wring from our understanding of physics is a step in the right direction.

Check out the LDX in action below.

[MIT News]

18 Comments

I'm no nuclear physist here or anything of the sort but there always was a question that i have been asking myself. Since this phenomena is the same that occurs in the sun, wouldn't it also lead to some kind of much smaller size supernova? I hate to be pessimist but although still not attained, the idea that virtually endless output of energy from the fusion might someday be real just seems too 'easy'. Would someone enlighten me if I am totally wrong?

I'm not a nuclear physicist either but I don't think the purpose of this experiment is to create a supernova. I mean, the sun is massive and when you compare what MIT is making in the lab to the shear size of our sun, I don't think that the experiment will have anywhere NEAR the amount of energy that a real supernova (or a star for that matter)has. So you can sleep easy tonight.

supernova impossible, different fuels, hydrogen and magnet, different mass, think thats important. Plus, once youve become a star you cant be turned off at any time and re adjusted or sold or put in a big room 1 mile beneath Area 51.

I think.

A supernova has several requirements that will most likely never be recreated on the Earth, the most prevalent of which is the requirement of MUCH more mass. The experiment would have to fuse atoms into elemental iron, and with that much energy, it's virtually impossible.

MIT makes my dick move

If only I were born about 25, maybe 50 years from now.

why don't they spin the giant magnet to see what that does? i mean it probably already is but it seems like it would mimik the planet's magnetic feild a little better if it had a slight wobble to it since you know the earth spins on the geological axis and not the magnetic one. just a thought.

btw, the 'tire-sized magnet' is actually a superconductor

As long as there is no nuclear waste of any kind and it doesn't take the whole US budget and fifty years to build one.

"As long as there is no nuclear waste[...]"

'Nuclear waste' is a tremendous resource. If the decision was up to me Sweden would enthusiastically take unlimited amounts of fission waste as long as long as it was in a uranium dioxide form(e.g. spent light water reactor fuel) and properly packaged in durable dry storage casks.

Not only does it still contain 95-99% of it's original energy content, it contains very valuable materials like platinum group metals that are perfectly safe to use after 100 years of cool-down. The storage casks would just be housed in what is essentially big, covered parking lots until ready for reprocessing.

The transuranics(neptunium, plutonium, americium etc.) are what makes the so-called waste necessary to store for more than just a few centuries. These materials are actinides; that's just another name for potential fuel.

Sweden has no oil, no coal, no gas and even if it did, we should not waste these precious materials on mere vehicle fuel and electricity; they are chemical feedstocks.

I have very little hope for fusion to work out in the next century, even less hope for renewables(except for hydro, which we've already capped out). Even if someone pulls a rabit out of a hat and managed to get fusion to work, it is likely that early fusion reactors will require a fission blanket to amplify the power output of the reactor and generate extra neutrons to assist with tritium breeding and spent fuel is eminently usable for this.

one step closer to a green world...

I wonder how they cool the superconducting magnet in the middle if they have super-hot plasma all around? It seems like this device could only work for a short period of time before you have to shut it down to add more coolant.

An efficient way to harness fusion power is the aneutronic reactor, it has an improved concept to a sustainable fusion reaction, that can provide a source of neutron-free electrical energy. www.crossfirefusor.com/nuclear-fusion-reactor/overview.html

I would like to know more about the construction of the superconducting wire coils.

Perhaps they are insulating the magnet from the plasma by shrouding the magnet in a doughnut shaped vacuum tube?

The SUN will never become a super-nova, it does not have sufficient mass. When our SUN gets near it's end of life, it will turn briefly (where briefly mean briefly in terms of the life of the sun) into a red giant, then it will simmer as a yellow dwarf while it cools off over time.

That red giant will become very large. It will definitely envelope Mercury and Venus and there is some debate whether the photosphere will actually envelope the earth as well. But this is not for a few billion more years so we don't have to get out of dodge just yet.

While I dunno bout fusion based power generation, I do believe this is the way to things like lightsabers and other devices that use the spun-up plasma itself as the power source. Sure, we lose a lot dropping back down to a laser, but if we also get the capability to carry the diapole-plasma around, then it's just another form of battery. Emmitter is through a one-atom aperature per beam screen. We'll even get the ability to transmit some waveforms via remote.

We need to be basing a larger number of students in applications based production techniques; where the prior existence of the laser and everything about photon sciences isn't necessarily the goal. Building the infrastructure into our society for working with beamlines in everyday life. A logical place in our society to place that responsibility is in the hands of those who have to personally sell the idea of optically driven technologies at the very least to their own age group. Others will catch up quick. I'd like to see a few of our facilities that get shut down develop and run a public beamline. A few anchor points with major storage capacity, but an aerially based waveform. Try for electron gain from the planet as well as neutron propagation. A pipeline of a new sort for America. Superfluid dynamics in everyday life would be the natural pairing. Perfecting low cost containment. Either we sell new stuff, or others will sell us new stuff. We need to make new stuff.



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