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MIT's New Tabletop Particle Detector Sees Individual Electrons

Posted by Soulskill on from the will-fit-inside-your-smartphone-soon dept.

An anonymous reader writes: Scientists at MIT have created a small, tabletop particle detector capable of identifying individual electrons within a cloud of radioactive gas. "As the radioactive krypton gas decays, it emits electrons that vibrate at a baseline frequency before petering out; this frequency spikes again whenever an electron hits an atom of radioactive gas. As an electron ping-pongs against multiple atoms in the detector, its energy appears to jump in a step-like pattern." The researchers used the detector to record the activity of 100,000 different electrons within the gas (abstract). They're hoping that with enough data about how the electrons bounce around, they'll be able to pinpoint the amount of energy released during these krypton atom decay events. Once they know how much energy is released, they can figure out the mass of a neutrino, which is also emitted during the decay.

27 comments

  1. this news brought to you by lex luther by amias · · Score: 1, Funny

    and then we will finally be able to pinpoint supermans lair

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    1. Re:this news brought to you by lex luther by Anonymous Coward · · Score: 0

      Science is such bullshit. What is this crazy krypton has electrons talk?

  2. Do electrons vibrate? by wonkey_monkey · · Score: 1

    it emits electrons that vibrate at a baseline frequency

    Do electrons actually vibrate? Or is this one of those cases where a scientist has dumbed it slightly and a journalist had taken very third word and jiggled them about until they make a vaguely coherent sentence?

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    1. Re:Do electrons vibrate? by Thanshin · · Score: 0

      Everything vibrates.

      Everything's a dildo if you're brave enough.

    2. Re:Do electrons vibrate? by Anonymous Coward · · Score: 1

      As was mentioned elsewhere, yes, at ~78GHz in this case. Electrons _always_ vibrate. We couldn't exist, and neither could the Universe, if they didn't.
      I was working during the era from when Phonons went from a Theoretical Construct to something that was easily measured.

      This is a really good experiment. Within a highly stable and accurately measured Magnetic field, the F/DeltaF can imply Neutrino Mass.
      I actually had a First Edition of Lawrence's original paper on Cyclotron Resonance...
      Fascinating stuff, and the Math is actually easy.

    3. Re:Do electrons vibrate? by radtea · · Score: 4, Informative

      Do electrons actually vibrate?

      No.

      The electrons emit cyclotron radiation, because they are being accelerated by a magnetic field. The acceleration is always perpendicular to the electron's velocity vector, so they don't speed up, they just turn in a circle. However, all accelerating charges emit electromagnetic radiation, and in the case of an electron moving in a magnetic field in this fashion it is called "cyclotron radiation". In other contexts it is called "bremsstrahlung", and so on. Physicists often have multiple names for the same basic phenomenon manifesting itself in different circumstances.

      Add "electrons vibrate" or "everything vibrates" to this account adds nothing and obscures the actual source of the radiation, which is continuity conditions on the electro-magnetic field. These conditions are described by Maxwell's Equations, which predict such radiation. There is exactly nothing in Maxwell's Equations that could be said to describe a "vibrating electron" in this context.

      The summary is equivalent to an account of a baseball game written by someone who has never seen a ball, or a game, of any kind. It is depressing that "science journalism" scrapes along at a standard that is an order of magnitude below anything found in sports journalism, which is itself not exactly a paragon of insight and coherence.

      The paper itself can be found here: http://arxiv.org/pdf/1408.5362...

      It is a beautiful piece of work that really does open up new doors to precision measurement of beta spectra.

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    4. Re: Do electrons vibrate? by Anonymous Coward · · Score: 0

      But not at her baseline frequency.

    5. Re:Do electrons vibrate? by danlip · · Score: 3, Insightful

      Electrons are repulsed by their fellow electrons, making them most definitely not homosexual. They are known to have violent relationships with positrons, and clingy relationships with protons.

    6. Re:Do electrons vibrate? by wonkey_monkey · · Score: 4, Funny

      and clingy relationships with protons.

      But usually the protons are shacked up with neutrons, so the electrons are forced to keep their distance.

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      systemd is Roko's Basilisk.
    7. Re:Do electrons vibrate? by wonkey_monkey · · Score: 1

      Thanks for taking the time to post your response. May I draw your attention to this AC, who claims that

      Electrons _always_ vibrate. We couldn't exist, and neither could the Universe, if they didn't.

      as I get the impression you might know more about it than he does?

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      systemd is Roko's Basilisk.
    8. Re:Do electrons vibrate? by Anonymous Coward · · Score: 0

      Don't you know even basic physics? Electrons are fermions; they are exclusively heterosexual. Bosons like protons are homosexual.

    9. Re:Do electrons vibrate? by Anonymous Coward · · Score: 0

      We are both right, but the Maxwell Demon is in the details.
      Electrons _always_ vibrate, but Quantum Physics only allows certain discrete elevated energetic states. Without enough energy added or subtracted, they just sit there and mumble a bit in whatever state they are in. Nevertheless, even the coldest electron vibrates. This is why Heat. So, Phonons.

      "The electrons emit cyclotron radiation, because they are being accelerated by a magnetic field."

      No. They are not "accelerated", in an "Accelerator" sense, they are perhaps "trapped" in orbits for a while. For a _very_ fixed Magnetic Field, if the Electron energy is too low, it spirals inward, if too high, it spirals outward, and if just the right energy, they happily maintain a fixed wiggling orbit. Note that these are very low energy electrons, so Synchrotron Radiation Loss effects are insignificant. They can orbit for years, and they can be delicately probed for EM Fields, in this case, RF, with _very_ subtle results. Cyclotron Radiation is just one form of externally provoked Electron Vibration, under strict definitions of Vibration.
      I'm not sure of the actual precision of their Frequency measurement, but One part in a Quadrillion should be now easily achieved.
      (Note that by Classical Mechanics Math, the Electrons can be assumed to be "Accelerated" in such a Field, but they don't actually gain any real energy in _this_ timeframe. Here is where the Math and Physics get _very_ complicated; and any "Energy" gained from this large Field ends up being very, very, small.)

      "It is a beautiful piece of work that really does open up new doors to precision measurement of beta spectra."

      Very much yes, but...
      Why bring Maxwell into it? Maxwell was Right, but over the last century, we have gotten Righter. Remember Pauli?
      Anyway, a surprisingly good summary was just published in TheRegister. Whoever wrote that MIT puff piece should be flogged:
      http://www.theregister.co.uk/2015/04/22/boffins_invent_machine_to_see_electrons/

      WET-RIXS

    10. Re:Do electrons vibrate? by xfade551 · · Score: 2

      Do electrons actually vibrate? Or is this one of those cases where a scientist has dumbed it slightly and a journalist had taken very third word and jiggled them about until they make a vaguely coherent sentence?

      Yes, they indeed do; see "de Broglie wavelength" from http://en.wikipedia.org/wiki/M.... The AC that said, "Everything vibrates," as trollish as that sounds, is correct.

    11. Re:Do electrons vibrate? by EnsilZah · · Score: 1

      I think it's safe to assume any word used to describe something at that scale is at best an analogy to what it means at the human scale.

    12. Re:Do electrons vibrate? by Anonymous Coward · · Score: 0

      You bring up a valid point, but as the AC who posted a more detailed, but without Math, explanation of Electron Vibration above, I would like to emphasize a point:
      _Everything_ that we know about Physics, we know through Analogy. Even our current Math is an Analogy; as Einstein might have put it: "God does not write on a Whiteboard."
      Quantum Chromodynamics re-introduced an old concept: Make up silly Names so as to thoroughly disconnect the Name from the Property.
      As an Example...
      Spin.
      When young, while creating a Neutral Beam of Polarized 3He for one of his Experiments, I asked "Stretch" Conzett just what Spin was.
      He explained that "Spin" was a poor choice of a Name, and he traced out in his Logbook the original concept of Angular Momentum.
      The word "Spin" was coined by Pauli, for want of a better term. "Gyre" would have been much better, but Pauli didn't know his Lewis Carroll.
      Then Stretch drew a bunch of Matrices, explaining the allowed and disallowed States, thus the fundamental Quantum properties. At this point, "Spin" becomes downright misleading.
      He then drew a beautiful equation describing the Paths of a Polarized Light Ion in a Magnetic Field, and he said- "So you see, it Rotates around this kind of Axis. Spin is actually Right."
      He's the one that thought "Gyre" was a much better name, especially for slithy Second Year Engineering students who may have just discovered Maxwell, has only a dim concept of what follows, and who has never read Lewis Carroll.

      WETRIXS

  3. What's The Frequency, Kenneth? by Anonymous Coward · · Score: 3, Informative

    ""26 gigahertz,” Formaggio says."
    Actually, his name is Joe.

    ECR is fascinating to some of us... actually, very few of us.

    However, one statement in the article about another experiment is horribly wrong:
    “In KATRIN, the electrons are detected in a silicon detector, which means the electrons smash into the crystal, and a lot of random things happen, essentially destroying the electrons,” says Daniel Furse..."

    No,no,no,no,NO!
    The Beta particles get slowed down, trapped, and captured, and one or more neighboring electrons cascade out and eventually escape the Detector, to be counted. This is the principle behind Surface Barrier Detectors.

    Sheesh!

  4. Don't they mean hears electrons? by dfn5 · · Score: 1

    A radio antenna then picks up very weak signals emitted by the electrons

    IMHO, I think listening for electrons is a better analogy.

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    1. Re:Don't they mean hears electrons? by pe1rxq · · Score: 1

      Are your eyes also used for listening?

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    2. Re:Don't they mean hears electrons? by Anonymous Coward · · Score: 0

      Are your eyes also used for listening?

      He means that an ear is a better analogy of a simple antenna than an eye that picks up much more complex signals.

  5. Yeah, but... by Anonymous Coward · · Score: 0

    how fast are they moving?

  6. The Cloud by Tablizer · · Score: 1

    individual electrons within a cloud of radioactive gas.

    Jeez, even electrons are going with this cloud fad.

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  7. arXiv link to paper by dvase · · Score: 1

    http://arxiv.org/abs/1408.5362

  8. How much spin by Anonymous Coward · · Score: 0

    is needed to consistently roll 20 on a d20?