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Science Technology

3mm Inexpensive Chip Revolutionizes Electron Accelerators 113

AaronW writes "Scientists and engineers at the US DOE SLAC National Accelerator Laboratory and Stanford University have developed an advanced accelerator technology smaller than a grain of rice. It is currently accelerating electrons at 300 million volts per meter with a goal of achieving 1 billion EV per meter. It could do in 100 feet what the SLAC linear accelerator does in two miles and could achieve a million more electron pulses per second. This could lead to more compact accelerators and X-ray devices."
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3mm Inexpensive Chip Revolutionizes Electron Accelerators

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  • Unless you can somehow turn down the volume of the device, 300 Mev photons are high-power gamma rays, not x-rays. BTW unlike regular x-rays, at gamma energy levels you can actually activate matter, I.E. turn it radioactive.

    • by hankwang ( 413283 ) on Monday September 30, 2013 @02:29AM (#44989799) Homepage

      "300 Mev photons are high-power gamma rays, not x-rays."

      No, an accelerator of 300 MeV per meter over 3 mm gives you 1 MeV, or less if the actual field is over less than the chip size. Tuning down from there will easily get you into the x ray domain.

      • Ahh didn't see it was 300 Mev *per meter*. Small detail, thanks!

        • Ahh didn't see it was 300 Mev *per meter*. Small detail, thanks!

          This masterful demonstration of The Save reminds me of the way a cat lands on its feet no matter how it is thro^H^H^H^H^H^H^Hfalls.

    • by Anonymous Coward


      Neutron radiation != EM radiation (photons) != Beta radiation (electrons)

      Neutron radiation messes with nuclei and can make matter radioactive. EM radiation and beta radiation generally do not. Furthermore, you can't accelerate photons (x-rays and gamma rays) since they all travel at c. You can't accelerate neutrons because the only forces that act on them aren't macroscopically accessible. This is an electron accelerator.

      • Fair enough, just two questions:
        1) An electron hitting an atom will produce photons with the same energy via the Bremsstrahlung effect. As electrons will hit atoms sometimes, 300 MeV electrons means you will have 300 MeV photons, right?
        2) How much energy a photon needs to transmute an atom? I believe it's lower than 300 MeV (but as a commenter said, it's 300 MeV *per meter* so really you need a lot of those devices chained together for them to become dangerous, I guess)

        • by Anonymous Coward on Monday September 30, 2013 @03:26AM (#44989953)

          1) You'll probably get some photons out of the deal but they won't all be 300MeV. There are lots of places to put energy (this is what makes particle physics hard) and photons are only one of those places. See the light-matter interaction box on the "Photoelectric_effect" wiki page. At 1MeV, even pair production becomes viable.

          2) Photons don't transmute atoms (search for "photonuclear reactions" for the exceptions). Neither do electrons (look up "Electron_capture" for the exception, but it generally only happens with electrons already bound to the nucleus rather than ones flying around). Neutrons transmute elements because they can ignore the Coulomb barrier. Irradiating, say, rubber tubing with gamma radiation won't make it radioactive (it'll probably make some radicals and mess with the chemistry, but nothing nuclear). Neutron radiation is a totally different story.

          • Re: (Score:3, Informative)

            by Anonymous Coward

            The SLAC isn't a spallation radiation instrument. It produces xrays by coherent synchrotron radiation: as the electron beam passes through the end-stage undulators, the electrons are undulated at a fixed wavelength by a series of alternating undulator magnets, the wavelength of which is shorter (higher energy) than that of the spacing of the undulators because the electrons "see" the undulators as closer together due to time dilation, the electrons, still carrying over 99% of the bunch energy are then diver

          • My first thought when reading this was that it would an interesting exercise to make a free electron laser using this electron source.

          • photons over 1GeV can indeed transmute nucliei.

        • Re: (Score:3, Informative)

          by Anonymous Coward

          1. This accelerator, like SLAC (in it's current configuration), accelerates electrons, and the accelerated electrons are undulated (wiggled) in a vacuum to produce xrays (photons), then the electron beam is deflected off-line into a beam absorber, nearly all of the beam energy at SLAC is discarded, rather than reaching the experimental target. This is unlike most xray sources which generate xrays by spallation (collision with atoms), as the energy (wavelength) of the photons has the same bandwidth as the pa

          • Shouldn't the neutron be paired with something composed by its anti-quarks? If so, you'd need a photon with about 2TeV, what needs an accelerator at the "huge" end, not "lab-sized".

            Also, that's not my area so I may be completely wrong, but it looks quite unlikely that you'll generate exactly 6 quarks with different color and barionic numbers, so that they can organize as a neutron.

            • Also, that's not my area so I may be completely wrong, but it looks quite unlikely that you'll generate exactly 6 quarks with different color and barionic numbers, so that they can organize as a neutron.

              That would depend on if you are watching(or not)?

      • Re: (Score:2, Informative)

        by Anonymous Coward

        There are photoneutrons. If I recall correctly they are typically produced by high energy photons hitting deuterium. The neutron produced can go an activate material around it. For a nuclear reactor that has shut down, photoneutrons are the dominant form of source neutrons produced for a little while (the gammas come from beta decay which drops off over time).

    • by profplump ( 309017 ) <> on Monday September 30, 2013 @03:33AM (#44989977)

      The modern classification of x-ray vs. gamma-ray is based on the source of the emission (electron vs. nucleus), not the wavelength. []

      • Well, yes and no, it also depends on the field what term is used. Astronomers always name it gamma radiation, while physicists from the field of elementary particles and accelerators use the term gamma radiation only for radiation coming from the nucleus. X-ray radiation is used to specify the wavelength range, for any other source.
        • by ceoyoyo ( 59147 )

          Astronomers may call it gamma radiation because they don't know the source. It's true that most natural higher energy radiation is gamma while lower is x-ray, but there is overlap between the two and artificial or unusual sources (like particle accelerators) can produce very high energy x-rays, or very low energy gamma rays.

  • This could lead to more compact accelerators and X-ray devices.

    Just don't cross the streams. [] It would be bad.

    • I'm fuzzy on the whole good/bad thing. What do you mean, "bad"?

      • I'm fuzzy on the whole good/bad thing. What do you mean, "bad"?

        Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.

        [Or so I've heard.]

  • Inquiring mind here, but are there any interesting gadgets or household revolutions that we foresee on the horizon, if this sort of tech is commonly available?
    • from TFS

      developed an advanced accelerator technology smaller than a grain of rice

      You can get rice that cooks itself and you too! In soviet America , rice cooks you!

    • Re: (Score:2, Informative)

      by Chrontius ( 654879 )
      Your microwave oven will probably become much more mass-efficient and somewhat more energy-efficient.

      It might enable radars of similar size, cheap enough to mount in every air vent in your house and able to direct the chilled air at people; combined with similarly miniaturized heat sensors, you'll find yourself cooling off or warming up much more quickly after coming inside.
    • by fa2k ( 881632 )

      The main problem is that electrons of such high energy produce X-rays when they smash into something (or are accelerated), and X-rays are dangerous. One could imagine home X-ray scanners, if we could get through the regulatory clusterfuck. Maybe one could make a weapon, if the beam intesity was ramped up by placing many of htese in parallel.

      Particle physicists are planning the next thing after LHC, and it's a linear electron-positron collider. The device only claims to accelerate electrons to 1 GeV in the b

      • by hughk ( 248126 )

        the "International Linear Collider requires more than 1 TeV beams

        Is this because the LHC is wasting a lot of power with synchrotron radiation? The LHC is already running at about 3.5TeV/beam giving 7TeV collisions. With the upgrade, they should be able to manage 7TeV/beam.

        • by ceoyoyo ( 59147 )

          Proton and larger particle colliders don't really suffer from synchrotron radiation because the particles are so massive. Electrons are very light so they have to be travelling much faster to have the same energy, thus synchrotron radiation becomes a problem.

          Physicists want an electron collider because electrons are fundamental particles. When you smash two of them together (or an electron and a positron) you get a nice clean collision. Protons are composite particles and what you get depends on how the

      • by ceoyoyo ( 59147 )

        That's 1 GeV per metre.

  • by Anonymous Coward

    The US govt is interested in getting cheap proton therapy machines. Instead of cutting a human open with an expensive surgeon to remove a tumor, the computer controlled proton beam can blast through the skin, and strike the tumor. So yes, this is going to get lots of govt funding. Gains in particle accelerators are merely incidental.

    • by HiThere ( 15173 )

      Proton? But this is an electron accellerator. You could use it to feed a proton accelerator, I suppose....but it wouldn't be simple.

      Better to build something analogous and feed it with hydrogen ions. Also note that it requires a preheater stage, and that protons don't have synchroton radiation. So anything analogous is going to be QUITE difficult. (OTOH, protons don't need a linear accelerator, they can use rings.)

      Actually, I think nothing even analogous would work for protons. And even doing it with

  • by tommeke100 ( 755660 ) on Monday September 30, 2013 @07:41AM (#44990659)
    > "This could lead to more compact accelerators and X-ray devices."

    ...and weapons.
  • Why spend 8 billion Euro on something that will be in every kid's room in 5 years? I fully expect "My First Large Hadron Collider" from Fisher Price in a few years so that kids can make their own micro-singularities and find out how meaningless the "God Particle" actually is for themselves.

    • Because unless you spend 8 billion on it the first time it never gets to be a children's toy. That 8 billion is the initial investment in these things being commonplace enough to use as cat toys. (If you for some reason want to irradiate kitty's bones, I guess....)

  • If these cold be produced in large quantities and were cheap enough, I wonder how well we could progress in the creation of antimatter. If we could do so, and could improve the penning trap so that the antimatter could be kept for a long time, then many problems with space travel would be solved.

  • I read a PhD dissertation and was instructed by a professor working on the idea of using chanelling in crystal material to accelerate particles. What was not included then was the addition of lasers. That was the mid 1980s.

  • Yes, I know - made-up technobabble straight out of the sixties - but the FX were killer for the day, and I wants one. This looks like a fairly portable source of high energy plasma to me, a necessary first step. Not much of it, but we can work on that later.
  • Won't scale (Score:4, Insightful)

    by Chalnoth ( 1334923 ) on Monday September 30, 2013 @12:39PM (#44993279)

    At least, it won't scale in the way the article suggests.

    It's possible that the tech involved might make for a more efficient acceleration mechanism than the current superconducting electromagnets, but I sincerely doubt it will lead to significantly smaller accelerators: accelerators are large not because it isn't possible to accelerate the electrons in a shorter distance, but because it's extremely inefficient to do so.

    Large accelerators are limited by the fact that rapid accelerations of charged particles cause lots of radiation to be emitted. The amount of radiation emitted increases dramatically as the particles approach the speed of light, making it harder and harder to push the particles faster (or even just to keep them going at speed in a ring for circular accelerators). Even if this mechanism of electron acceleration is a hundred-fold more efficient energetically than the SLAC accelerator, it still couldn't accelerate electrons to SLAC speeds in 100 feet, because it would need vastly higher acceleration and that higher acceleration would lead to lots of radiation, limiting the pace of acceleration. Personally, I doubt it's 100 times more efficient. I bet most of that efficiency difference comes from this small device not operating on electrons moving anywhere near the speed of light.

  • Opening the first link in a new tab led me to get redirected to [], which seems to be a "MoboMarket.apk" file. Anyone else?

In seeking the unattainable, simplicity only gets in the way. -- Epigrams in Programming, ACM SIGPLAN Sept. 1982