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MIT Scientists Demo 150 Ton Magnet For Plasma Research 56

Posted by timothy from the limitless-free-energy-just-wait-a-few-months dept.
Dr.Luke writes "The dream of abundant fusion energy just got a step closer to reality. MIT scientists just demonstrated a mammoth 150 ton magnet that could be used to create powerful plasma container needed for a practical fusion power plant. The device produces a magnetic field 260,000 times stronger than that of Earth. Full story here."
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MIT Scientists Demo 150 Ton Magnet For Plasma Research More

MIT Scientists Demo 150 Ton Magnet For Plasma Research

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  • How long until I can buy a fusion power supply for my Linux box?

  • I can finally get all that change out from under my cushions!


  • BUGS BUNNY points the giant magnet towards the airplane, piloted by ELMER FUDD and makes him crash into a tree

  • I can see the quotes now... (Score:5, Funny)

    by stienman ( 51024 ) <adavis&ubasics,com> on Tuesday September 24, 2002 @04:23PM (#4322663) Homepage Journal
    Scientist, "Yeah, so, like, the fusion reaction can put out, you know, a lot of power - like 10,000 amps or so."

    Reporter, "And how much current does the one smaller magnet consume again?"

    Scientist, "Uh... 46,000 amps. But it's so cool! I mean, it glows and stuff!"

    ...

    3) Profit!

    -Adam
    • <big dork>An amp is a unit of current. A watt is a unit of power.</big dork>

      -Gabe
      • Given that these are superconducting coils the amperage relates more to power than it does in a situation where the resistance is unknown.

        In other words, amperage is simply a measure of the number of electrons passing a cross-section of the wire in a given period of time. In this instance it is enough to give significant measure of the input power.

        It is, however, inadequate in measuring the output, but since they didn't give any further info in the article I chose not to expand my narrative further than the nebulous Amp.

        Gravity: Not just a good idea, it's the law.

        -Adam
  • Does a magnet of theis sort have any external magnetic field or is all the force focused inward?

    NASA had the idea a few years ago to use a magnetic field to generate a bubble full of plasma to act as a solar sail.

    If this even reaches break even as a fusion reactor, this becomes a spacecraft propulsion device. It generates the energy to power the magnet and the plasma to fill the bubble.

    Makes me wonder if NASA will catch spinoffs from the DOE. The world seems to have changed a bit.
    • The nasa plan doesn't need a huge magnet. A much smaller magnet is used to create a field, which is then "inflated" with plasma. Don't ask me how that works, but supposedly injecting plasma into the field can stretch it out to a few kilometers across so that it acts as an almost zero mass solar sail.
    • I believe this is what you are referring to:
      http://www.geophys.washington.edu/Space/SpaceMod el /M2P2/

      A great site, though I wish they could get moving on... I'd love to see a probe get launched and "whip" out of the system...can't hurry progress I suppose.

      The magnets(solenoids) in the M2P2 program are much much less massive, since they need to balance strength of the plasma field/bubble and containment of the plasma over time with mass of the entire system over the operational scope of project.

  • Sign on the door (Score:5, Funny)

    by quintessent ( 197518 ) <my usr name on toofgiB [tod] moc> on Tuesday September 24, 2002 @04:47PM (#4322829) Journal
    Warning: Any metal objects in pockets will be confiscated without warning.
    • Or, even worse.. I hope you don't have any implants using surgical steel. I used to have an internal fixation on my femur, and I used to have a good time at metal detectors. Lets just say I never would have been able to get a MRI.
      • I had a professor in college who had an issue regulating the current in his brain's emotional centers. After he was in and out of mental institutions for a while growing up, his family took him to a brain surgeon.

        They figured out that when he had encephalitis as a child, he had caused this brain damage (due to high fever for an extended period of time), and they opened him up, installed a small chip to function as a voltage regulator, ran a cable down his skull and neck to his chest, where there was a subdermal microwave transducer that turned microwaves into electricity to power the chip in his brain.

        His charger broke one year, and he didn't realize it. He started getting more and more irritable until he realized that he wasn't getting as much juice as he needed. He switched to his backup charger, and started having office hours again :)

        Now, this is relevant because he DEFINITELY couldn't have had an MRI. Just imagine that cable spinning around in his brain. "Scrambled Brain, anyone?". Second, before you say that this must be an urban legend, I saw this guy, was in his classes for 3 years, and he brought in X-Rays. Email me for me details :)
      • Surgical Steel (at least recently) isn't ferromagnetic. My brother has huge plates in his arm and leg, along with a pole in his femur. He doesn't have a problem with magnets or metal detectors. I even stuck a neodymium magnet up to his plate and it didnt stick....
    • Warning: Any teeth with metal fillings will be confiscated without warning.

      -
    • That's pretty realistic. A while back, I talked to a guy who worked at SLAC (Stanford Linear Accelerator). He said once he walked by their giant magnets, and it erased his credit cards.

      But that's still not as cool as when scientists levitated frogs with magnets [sci.kun.nl]. Since virtually all organisms have small traces of iron in them...all that's needed is an extremely powerful magnet to levitate 'em.

      Heh, it makes me wonder if this magnet is strong enough not to just rip metal objects out of your pockets, but to *attract you* into it. =)

      --- "A black hole is just God dividing by zero."

      • Since virtually all organisms have small traces of iron in them...all that's needed is an extremely powerful magnet to levitate 'em.

        Actually, the levitation was caused by the diamagnetic properties of water in the animals. Some(all?) nonmagnetic materials actually display diamagnetic properties in a very powerfull magnetic field. (they are pushed away from the field, rather than drawn towards it)

        Anyone care to elaborate on this?

  • ...a 2.5 million ton refrigerator to stick it on.

  • A pulsed 13 Tesla magnet and its problems (Score:3, Insightful)

    by kgp ( 172015 ) on Tuesday September 24, 2002 @05:00PM (#4322927)
    In the article it says:

    A superconducting magnet operated on a constant current, such as those used in Magnetic Resonance Imaging of the body, suffers no dissipation of electrical energy. That is not true, however, when a superconducting magnet is pulsed. And tests of the new magnet in pulsed operation showed that "initially [the electrical] losses were much higher than predicted," Minervini said.

    With repeated operation, however, the magnet appeared to correct itself. "With each cycle the losses lessened until they reached a steady value a lot closer to what we'd predicted," Minervini said.

    "We think we understand what's happening, at least qualitatively," he continued. "It has to do with interactions between the thousands of wires twisted into cables that in turn are coiled to form the magnet. We are essentially changing the electrical characteristics of the cable in a way that decreases losses over time."

    No. That's restating the problem. You don't have the understanding bit here. What is going on that will change the (I presume) I squared R losses in the magnet.

    • Re:A pulsed 13 Tesla magnet and its problems (Score:4, Informative)

      by caffeinated_bunsen ( 179721 ) on Tuesday September 24, 2002 @11:37PM (#4325253)
      No. That's restating the problem. You don't have the understanding bit here. What is going on that will change the (I presume) I squared R losses in the magnet

      Quick bit of advice: Don't casually presume that you know more about the subject of the article than the PhDs who contributed to it. The whole point of a superconducting magnet is that R=0, so there is no I^2 R loss* in the magnet.

      But when you build a magnet like this, you can't calculate the magnetic force on every centimeter of superconducting wire in the whole thing. You also can't make the wire stay precisely where you put it. As the field builds up the first time, all the wires move around a little bit, due to the very large magnetic forces on them. This wastes some of the energy put into the field. As you cycle the field, the wires gradually move toward an equilibrium and the mechanical energy loss goes to zero.

      I'm sure there are other factors, but this is the only one that I can remember off the top of my head. In fact, I know that there's more than this to the problem, because this is a well-known phenomenon that everybody who designs high-field magnets has dealt with. If it were as simple as this, they never would have mentioned it in the article.


      * Of course, there are some losses in type II superconductors due to the motion of flux vorticies. But this doesn't behave quite like an Ohmic resistance, and the loss is really small in good alloys.

  • "150-Ton Magnet Pulls World Toward New Energy Source"

    At several orders of magnitude more powerful than the Earth's own field, that title seems uncomfortably literal.

    Yes yes, I know you can't actually move the planet that way, and yes yes, the field only exists inside the magnet. Lighten up.

    Of course the earth's field's VOLUME is just a bit larger than the one this thing generates...

    According to the article, this magnet can generate 13 Teslas. Are Telsas a linear scale, or a logarithmic one?

    PS: Somebody at Berkeley built a 14.7 tesla magnet (current world record) that weighed in at "several tons" (according to their press release). So this 150 behemoth is Really Powerful, but not the badest boy on the block.

    • 1 tesla = 10,000 gauss

      and yes, teslas are a linear scale.
      • My hazy recollection of E&M wants to say that no quantity of tesla and gauss will ever be equal because they measure different things. Both pertaining to magnetism, but there is a subtle difference between the two, what that is I can't quite recall at the moment, but there is a difference
    • As the last reply stated, teslas are linear, just as most physical units are. As for field strengths, 13 T is only considered large for static-field magnets. Pulsed-field magnets can break 40 T without much trouble, but in much smaller volumes than this beast.

      The important thing about this magnet isn't the field strength - it's the volume in which the field is that strong, as well as the geometry of the field. You need some pretty fucked-up fields in order to effectively confine plasma, and those fields can only be generated with hideously complicated magnet designs.

    • Teslas are a linear scale. The Earth's magnetic field is ~5x10^-5 T, so this magnet's field is approx. 260000 times stronger than Earth's.

  • Field of the earth is tiny... (Score:5, Interesting)

    by Mt._Honkey ( 514673 ) on Tuesday September 24, 2002 @05:08PM (#4322980)
    The device produces a magnetic field 260,000 times stronger than that of Earth.
    I don't understand why the news always uses the field of the earth for these kinds of comparison. The earth's field is quite weak, barely enough to point a compas north. An old, weak refrigerator magnet, by comparrison, easily overpowers it from quite a distance. They would be better off using comparisons such as refirgerator magnets or MRI machines, something that people have more contact with and is stronger.

    On as side note about public ignorance about science, MRI (Magnetic Ressonanse Imaging) is really NMRI (Nuclear Magnetic Ressonanse Imaging), but because the public is so affraid of anything with the name Nuclear or Radiation or Commie in the name, the word Nuclear is always left off.


    Please forgive my spelling

    • Re:Field of the earth is tiny... (Score:1, Funny)

      by Anonymous Coward
      On as side note about public ignorance about science, MRI (Magnetic Ressonanse Imaging) is really NMRI (Nuclear Magnetic Ressonanse Imaging), but because the public is so affraid of anything with the name Nuclear or Radiation or Commie in the name, the word Nuclear is always left off.

      In addition, if one enters a place of medicine in certain parts of the United States and requests an "en-em-er," one will get a treatment that has absolutely nothing to do with nuclear magnetic resonance.

      Yes, this has happened.

    • I've never heard people being afraid of 'nuclear'. In fact, I don't even know what 'nuclear' is. I've heard of 'nucular', but I don't know if that's related or not.
    • (* They would be better off using comparisons such as refirgerator magnets or MRI machines, something that people have more contact with and is stronger. *)

      It would be kinda weird to open up a scientific journal and see things like, "....it was measured carefully and varied between 42.17 Fridgemags and 71.83 Fridgemags....."
      • You don't find "30,000 earthfields" in them either. We're not talking about scientific journals, we're talking about articles directed at the general public. Scientific journals use established units such as Testla, which the general public wouldn't have any grasp of. Hell, I'm a physics major, and I can't even grasp how big a testla is.
  • This is interesting news, in that the US pulled out of the international ITER project some years ago. Originally, that tokamak was supposed to reach ignition and sustained burn. The project was scaled down due to cost issues.

  • wouldn't this be a bit dangerous? (Score:3, Funny)

    by moosesocks ( 264553 ) on Tuesday September 24, 2002 @05:36PM (#4323161) Homepage
    In other news, every CRT located within two miles of the magnet is now in dire need of a degauss.

  • Meanwhile... (Score:5, Funny)

    by arban ( 89238 ) on Tuesday September 24, 2002 @05:38PM (#4323180) Homepage
    Meanwhile, at the conclution of the 34th International Orienteering Competition, no winner could be determined and 5 teams are unaccounted for. Feared dead. Film at 11.
  • Scientists have recently discovered the secret to making 3,000 ton refrigerators. Fat people around the world rejoice.
  • I immediately felt drawn to this story.
  • 260,000 times stronger than that of Earth

    Umm... the Earth's magnetic field is pretty damn weak. They should have compared it to the magnet in an MRI, or just given the gauss or tesla rating.... but then again, bigger numbers are more impressive to the people who dont know better. ...but it is pretty strong...
  • I can just read the headlines now:
    "Confused Hiker stumbles into Fusion Plant,
    Quoted as saying: "I thought my compass pointed North!?!"
  • I guess with a magnetic field that strong, they could also separate the hemoglobin from your blood plasma

    (for the humor-impared - that was a joke)

    Mind you, it probably could separate you from your fillings.

  • they talk about strong magnets being thousends of times stronger than the field of the earth, they forget to mention that earths magnetic field is really damn weak...
    At 0.6 gauss, this would mean this baby just surpasses 15 Tesla. Quite strong, but nothing uncommon.

    But really, a 150 ton magnet isnt very big if you look at the stuff they use at cern and other partical accelerator sites.

  • Technicians are required to eat a low-iron diet.

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