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MIT Scientists Demo 150 Ton Magnet For Plasma Research

Posted by timothy on 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."

20 of 56 comments (clear)

  1. Anyone else thinking cartoon here? by roachmotel3 · · Score: 2, Funny


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

  2. I can see the quotes now... by stienman · · Score: 5, Funny

    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

    1. Re:I can see the quotes now... by stienman · · Score: 3, Informative

      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

  3. Magnetic Bubble Sail. by Perdo · · Score: 2

    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.

    --

    If voting were effective, it would be illegal by now.

    1. Re:Magnetic Bubble Sail. by PhuCknuT · · Score: 2

      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.

  4. Sign on the door by quintessent · · Score: 5, Funny

    Warning: Any metal objects in pockets will be confiscated without warning.

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    Donate background CPU time to fight cancer.
    1. Re:Sign on the door by molo · · Score: 2

      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.

      --
      Using your sig line to advertise for friends is lame.
    2. Re:Sign on the door by Alsee · · Score: 2

      Warning: Any teeth with metal fillings will be confiscated without warning.

      -

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      - - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
    3. Re:Sign on the door by Transcendent · · Score: 2

      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....

  5. Now we need... by Krelnik · · Score: 2

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

  6. A pulsed 13 Tesla magnet and its problems by kgp · · Score: 3, Insightful

    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.

    1. Re:A pulsed 13 Tesla magnet and its problems by caffeinated_bunsen · · Score: 4, Informative
      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.

      --

      Bugrit! Millenium hand and shrimp!
  7. Article's rather ironic title by mstorer3772 · · Score: 2

    "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.

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    Fooz Meister
    1. Re:Article's rather ironic title by caffeinated_bunsen · · Score: 2
      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.

      --

      Bugrit! Millenium hand and shrimp!
  8. Field of the earth is tiny... by Mt._Honkey · · Score: 5, Interesting
    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
    --

    Don't Bogart the fish sticks
    1. Re:Field of the earth is tiny... by Tablizer · · Score: 2

      (* 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....."

      --
      Table-ized A.I.
  9. wouldn't this be a bit dangerous? by moosesocks · · Score: 3, Funny

    In other news, every CRT located within two miles of the magnet is now in dire need of a degauss.

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    -- If you try to fail and succeed, which have you done? - Uli's moose
  10. Meanwhile... by arban · · Score: 5, Funny

    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.

    --

    "You like Chinese food." -Fortune Cookie
  11. In other news... by blazin · · Score: 2

    Scientists have recently discovered the secret to making 3,000 ton refrigerators. Fat people around the world rejoice.

  12. Warning by Tablizer · · Score: 2


    Technicians are required to eat a low-iron diet.

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    Table-ized A.I.