Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
Science Technology

New Particle Collider Is One Foot Long 161

Jason Koebler writes The CERN particle collider is 17 miles long. China just announced a supercollider that is supposed to be roughly 49 miles long. The United States' new particle collider is just under 12 inches long. What the SLAC National Accelerator Laboratory's new collider lacks in size, it makes up for by using plasma to accelerate particles more than 500 times faster than traditional methods. In a recent test published in Nature, Michael Litos and his team were able to accelerate bunches of electrons to near the speed of light within the tiny chamber."
This discussion has been archived. No new comments can be posted.

New Particle Collider Is One Foot Long

Comments Filter:
  • by Anonymous Coward on Wednesday November 05, 2014 @07:19PM (#48322151)

    i'm so confused.

    • by Anonymous Coward on Wednesday November 05, 2014 @07:28PM (#48322199)

      No, only how hard you thrust particles.

    • by Anonymous Coward on Wednesday November 05, 2014 @08:07PM (#48322437)

      The Republicans took control of the Senate just yesterday, and we are already seeing results. American capitalism and Yankee ingenuity has beaten those big government and high tax liberal Europeans. This would have never happened if Harry Reid was still in charge.

      • by Anonymous Coward on Wednesday November 05, 2014 @11:19PM (#48323141)

        George W. made some huge contributions to particle physics during his presidency:

        President Bush met with members of the Fermi National Accelerator Laboratory research team Monday to discuss a mathematical error he recently discovered in the famed laboratory's "Improved Determination Of Tau Lepton Paths From Inclusive Semileptonic B-Meson Decays" report.

        Bush shows Fermilab scientists where they went wrong in their calculations.

        "I'm somewhat out of my depth here," said Bush, a longtime Fermilab follower who describes himself as "something of an armchair physicist." "But it seems to me that, when reducing the perturbative uncertainty in the determination of Vub from semileptonic Beta decays, one must calculate the rate of Beta events with a standard dilepton invariant mass at a subleading order in the hybrid expansion. The Fermilab folks' error, as I see it, was omitting that easily overlooked mathematical transformation and, therefore, acquiring incorrectly re-summed logarithmic corrections for the b-quark mass. Obviously, such a miscalculation will result in a precision of less than 25 percent in predicting the resulting path of the tau lepton once the value for any given decaying tau neutrino is determined."

        The Bush correction makes it possible for scientists to further study the tau lepton, a subatomic particle formed by the collision of a tau neutrino and an atomic nucleus.

        Bush resisted criticizing the Fermilab scientists responsible for the error, saying it was "actually quite small" and that "anyone could have made the mistake."

        "High-energy physics is a complex and demanding field, and even top scientists drop a decimal point or two every now and then," Bush said. "Also, I might hasten to add that what I pointed out was more a correction of method than of mathematics. Experimental results on the Tevatron accelerator would have exposed the error in time, anyway."

        Fermilab director Michael Witherell said the president was being too modest "by an order of magnitude."

        "In addition to gently reminding us that even the best minds in the country are occasionally fallible, President Bush has saved his nation a few million dollars," Witherell said. "We would have made four or five runs on the particle accelerator with faulty data before figuring out what was wrong. But, thanks to Mr. Bush, we're back on track."

        "It's true, I dabbled in the higher maths during my Yale days," said Bush, who spent three semesters as an assistant to Drs. Kasha and Slaughter at Yale's renowned Sloane High-Energy Physics Lab. "But I didn't have the true gift for what Gauss called 'the musical language in which is spoken the very universe.' If I have any gift at all, it's my instinct for process and order."

        Continued Bush: "As much as I enjoyed studying physics at Yale, by my junior year it became apparent that I could far better serve humanity through a career in statecraft."

        While he says he is "flattered and honored" by the tau-neutrino research team's request that he review all subsequent Fermilab publications on lepton-path determination, Bush graciously declined the "signal honor."

        "This sort of thing is best left to the likes of [Thomas] Becher and [Matthias] Neubert, not a dilettante such as myself," Bush said. "I just happened to have some time on the plane coming back from the European G8 summit, decided to catch up on some reading, and spotted one rather small logarithmic branching-ratio misstep in an otherwise flawless piece of scientific scholarship. Anyone could have done the same."

      • by Anonymous Coward

        SLAC is federally funded. It'll probably be shut down by the Republicans, so this stuff may go bye-bye.

        Anyway, what this seems to be is another advance in the area of wakefield acceleration. It's nice, but
        it's a technology that's been under exploration for decades now. It's nice to see progress, but it also
        clearly states that there's still a lot of work to do.

    • by Anonymous Coward

      So were they possibly working off a napkin sketch, a la ST's Stonehenge?

    • i'm so confused.

      It's more about width than length.

    • According to Mike Litorous, no.

  • Humorbot 5.0: So I said, "My particle collider is 12 inches long." [audience laughs]

  • Not exactly (Score:5, Informative)

    by Anonymous Coward on Wednesday November 05, 2014 @07:30PM (#48322211)

    If you read the article (damn you, paywall!) you note that this is essentially an afterburner, and does not start with stationary electrons. In this particular instance it requires a 2 km linear accelerator before the 12 inch magic booster box. 20 GeV electrons are accelerated by a further 1.6 GeV. Still interesting research, but definitely not what is claimed in the summary (surprise).

    • so no death ray then? I am so disappointed.
    • Thanks for the info, it's nice to have some idea what interesting thing the worthless summary was about.

      My first reaction was to "accelerated to nearly lightspeed". I mean yeah, obviously - that's kind of what a particle collider *does*. The interesting question is exactly *how close* to lightspeed we're talking, in terms of either speed or energy.

    • Re:Not exactly (Score:5, Informative)

      by joe_frisch ( 1366229 ) on Wednesday November 05, 2014 @07:55PM (#48322371)

      If you do a Google search on

      SLAC PUB plasma wakefield
      you will find a lot of non-paywalled papers on this and related plasma accelerator experiments at SLAC.

      • Re: (Score:1, Funny)

        If you do a Google search on

        SLAC PUB plasma wakefield
        you will find a lot of non-paywalled papers on this and related plasma accelerator experiments at SLAC.

        And if you use BSD or Slac you will not have to deal with a the over sized POS systemd configuration to accelerate your bits for packet collisions!

    • This is very interesting. I haven't studied physics since University over ten years ago, but it still an incredibly fun field to keep an eye on.

      I'd like to think that, as with most other current human endeavors, our capabilities are increasing by an order of magnitude on some consistent cycle, thanks to technology. It's sometimes hard to see just how fast we move as the human race lately. But any geek who's picked up a terabyte hard drive lately (that's the size of a credit card) and is old enough to
    • 20 GeV electrons are accelerated by a further 1.6 GeV.

      Can they be daisy chained? Could you line up ten of them, and boost 20 Gev up to 36 GeV in ten feet?

      • Re:Not exactly (Score:5, Informative)

        by Chalnoth ( 1334923 ) on Wednesday November 05, 2014 @08:43PM (#48322593)

        There's no problem in daisy chaining them, but I don't think you can guarantee the same energy boost each time. One of the big physics problems here is that accelerating charged particles radiate when they are accelerated, which acts as a sort of friction. The amount that is radiated increases quite dramatically as the particle gets closer to the speed of light (the energy loss scales as (E/(mc^2))^4). In practice, this means that if you dump a bunch of energy into an electron to accelerate it, you'll only add a fraction of that amount to its kinetic energy (the rest will be lost in radiation).

        Given this, the naive expectation is that each subsequent box will add less and less to the energy of the particles. The disclaimer here is that I haven't studied the specific physics of plasma shock acceleration, so I don't know how such acceleration scales with energy. I do know, however, that this is the exact same mechanism that is suspected to be behind the "oh my god" particles (single particles with more than ten million times the energy that the LHC can produce): plasma shock fronts in the galaxy accelerate some small fraction of the interstellar protons to unbelievable speeds.

        • If you do everything right, you should get the same added energy from each section. So a 10 GeV input beam woudl go to 11.6, and a 1000 GeV beam would go to 1001.6. The beams are ultra-relativistic - for all practical purposes speed of light (off by only a part in a billion) and this acceleration mechanism doesn't depend on the beam energy .

          • I checked, and electrons accelerated via plasma shocks do indeed emit synchrotron radiation. What is your source for this claim that the energy will be purely additive?
            • Its a good question .
              I don't understand astrophysical shocks, but see: []
              As far as I can tell the rely on magnetic fields bending the particles back into the shock.

              When relativistic particle trajectories are bent by magnetic fields, they emit synchrotron radiation which increases rapidly with increasing particle energy.

              Longitudinal fields don't do the same thing. There is a tiny amount of radiation, but it is not strongly dependent on particle energy. I believe this is becaus

      • Yes - in principal. You will need a separate bunch of 20 GeV drive electrons for each section, but that is not very difficult to do with a single accelerator. You need to separate the waste beam from the previous stage and the magnetic system to do that may be inconveniently long unless there is a beam-optics trick (which there may be).

        Staging two sections together is on the list of things that they are going to try. The eventual goal is to put together a lot of stages to get to TeV scale energies.

    • Re:Not exactly (Score:4, Interesting)

      by rgbatduke ( 1231380 ) <> on Wednesday November 05, 2014 @08:37PM (#48322563) Homepage

      Besides, the invention of accelerators order of 12" in size is very, very old news. The Betatron: []

      is, as one can see, order of a foot in diameter and could produce electrons at order of 6 MeV in 1940. Yes, that is actually before the US entered WWII and long before the invention of the cyclotron. That is gamma ~12, or v ~ 0.997 c. So if the top presentation were at all relevant to TFA it would actually be boring. One might safely conclude that it is wrong and boring.

      The betatron was damn near the first particle accelerator truly worthy of the name, and was just about exactly 12" in diameter (a bit larger than that including the frame for the magnets etc) as one can clearly see in the second photo on this page if not the first.


    • If you read the article (damn you, paywall!) you note that this is essentially an afterburner, and does not start with stationary electrons. In this particular instance it requires a 2 km linear accelerator before the 12 inch magic booster box. 20 GeV electrons are accelerated by a further 1.6 GeV. Still interesting research, but definitely not what is claimed in the summary (surprise).

      Wait, there's a paywall? Must not be much of a paywall since I wasn't trying to circumvent anything. Only thing special about my setup is scripts don't always run automatically without my permission.

    • > essentially an afterburner, and does not start with stationary electrons

      No major accelerator does. Most of them start with something simple like a Crockoff-Walton or even a van-degraff, then inject them into a series of ever larger synchrotrons. LCH has something like four or five "injectors" in a chain.

      In any event, plasma wake accelerators have been around for years. They don't work. This one won't either. Plasma just doesn't work the way any of our ever increasingly complex computer simulations say

      • by tibit ( 1762298 )

        They do add 1.2GeV to the beam in that foot-long box. It obviously works. The question is whether it is useful or not, but calling it "not working" is, well, ignoring the facts.

    • So you bang your gf for 73 seconds, then the porn star comes in to finish her off? Got it.

      / why does this summary inspire so many penis jokes?
    • by tibit ( 1762298 )

      Still, it's not inconceiveable that a couple dozen of such boxes can't start with a CRT e-gun for an injector and end with 20GeV, right?

  • by 602 ( 652745 ) on Wednesday November 05, 2014 @07:42PM (#48322285)
    Here's a tabletop particle accelerator in Scientific American's Amateur Scientist column in 1959: [] And in the Sept 1953 issue, an account of some high school students in El Cerrito who built a cyclotron.
    • by Matheus ( 586080 )

      Not the same thing but thanks for the link!

      As the article describes this is a high energy accelerator that takes a 20GeV beam and accelerates it by 1.6GeV. That acceleration in 12" is what is the key here. The above linked article will allow you to build a relatively small accelerator measuring in the 100s of KeV but those traditional methods require a significantly larger device to get the beam in the MeVs or higher.

      They needed a 2 km linear accelerator to get to 20GeV and added 8% to that in 1 foot.


      • by Lawrence_Bird ( 67278 ) on Thursday November 06, 2014 @10:10AM (#48325425) Homepage

        First, this work is not really new, its just a derivative of laser wakefield techniques. Further, it is not apparent that this will scale properly. Just because you can get a nice gradient in the low GeV range doesn't mean you can continue the same at TeV energies.

        I would also point out that it is not simply enough to accelerate one small bunch of electrons/positrons (or even protons). Luminosity is also a very significant factor in particle physics.

        But it is good to see that research is continuing on high gradient alterntiaves to cyclotrons and synchrotrons.

    • by VAXcat ( 674775 )
      AAIEEEE! I don't' know what I'd be more scared of - the X-rays this thing generates, the high voltage potentially lethal power supplies, the flying glass when one of the reservoir jugs breaks, or the incredibly toxic vaporized mercury!!! in the diffusion pump. People didn't scare very easily back in the 50s
  • Not a collider (Score:5, Informative)

    by AchilleTalon ( 540925 ) on Wednesday November 05, 2014 @07:49PM (#48322323) Homepage
    Actually, it is the accelaration module that is 1 foot long. It is not a collider, it is an accelerator a collider would be at least two feet long and in reality would have more than one acceleration module.
  • by joe_frisch ( 1366229 ) on Wednesday November 05, 2014 @07:52PM (#48322335)

    I am peripherally involved in the SLAC plasma wakefield accelerator described in the article.

    It provides a very high energy gain in a short distance, but needs to be driven by a high energy drive beam. The present design uses a 20GeV drive beam (using part of the old high energy physics accelerator).The required drive beam energy could be reduced to ~10GeV but probably not a whole lot lower. So this is a way to build a relatively short very high energy accelerator, but not a way to build a very short low-medium energy machine.

    Other labs are working on laser driven plasma accelerators that do not need to start with a high energy beam, but do need an enormous laser system and are presently limited to much lower average beam powers .

    Plasmas are very promising for future accelerators and there was some excellent work done at SLAC as well as laser / plasma accelerators at other labs. There is still a lot to do. There are issues with staging multiple plasma cells to get high energies, beam quality and stability issues etc.

    • So the beauty of this would be to take the plasma bit and stick it on the end of the Hadron collider, right? You could significantly boost the energy and speed without rebuilding the entire collider by using a very tiny bit at the end. Is that correct?

      • by joe_frisch ( 1366229 ) on Wednesday November 05, 2014 @08:55PM (#48322647)

        That is a slightly different concept. This uses a medium-energy (20GeV), high current electron beam to drive the plasma, which then accelerates a high energy beam.

        There is also a scheme to use a high energy proton beam to drive the plasma, and a scheme to use a high power (Peta-watt) laser to drive the plasma.

        All are being seriously considered / developed by various laboratories.

        This type of scheme probably doesn't apply well to a circular machine like LHC because the energy limit there is the magnets used to bend the beam into a ring .You might accelerate the protons at the end, but you wouldn't be able to send them back for re-use and you would not get enough collisions to get interesting physics.

    • Re: (Score:1, Funny)

      by Anonymous Coward

      So is this possibly an ion drive, adaptable to spacecraft?

      • Unfortunately for ion drives you want high current but very low energy. The amount of electric power required by an ion drive increases as the exhaust velocity increases, and for present day space applications you are better off with less particle energy, not more.

      • by Anonymous Coward
        Wakefield accelerators are space efficient compared to traditional high energy accelerators, but not energy efficient, especially when driven by lasers that might only be 0.1-0.5% efficient converting electrical power to light, not counting the inefficiencies in converting that light to accelerated particle power (you would probably be better off just shooting the laser out the back). A regular ion drive is pretty simple and a lot more efficient and works at much higher average power levels for a compact
    • Thanks for the comments. I read another article about this and they left us think it would be suitable to build medical accelerators and small size accelerators for many purposes. Apparently it is not the case.
    • Here is a paper about using lasers for very high performance accelerators with relatively short distances []. They are also wake field devices.

      A proper utilization of these phenomena and effects leads to the new technology of relativistic engineering, in which light-matter interactions in the relativistic regime drives the development of laser-driven accelerator science.

      The bulk of the paper is way beyond me, but it was still an interesting read.

  • by Anonymous Coward

    Your old desktop CRT would accelerate electrons to a reasonable fraction of c. A good accelerator will keep pushing the particles ever closer to the unobtainable speed of light so that they gain more and more mass. Physicists sometimes joke that their accelerators should really be called "ponderators".

    But, as others have already said, the summary sucks.

    • Silly thought experiment.. Accelerate ions you got from nuclear waste (Plutonium, Cesium, Strontium etc.) to relativistic speeds, then from our point of view the time will flow much faster for them and they'll quickly decay, giving you no significant remaining radio-activity. Though I wonder about the crap that escaped the beam - if it's not disrupted, and what crap is left in the beam that you have to get rid of.

  • ...with a 12" particle collider and a tiny scientist.

    • "What I wished for was a twelve inch"... wait a minute... um... I can't make that work.

    • Re: (Score:2, Funny)

      by ClickOnThis ( 137803 )

      Two fermions walk into a bar. One says "I'll have a beer." The other says "I'll have what he's having."

      • by Anonymous Coward
        The other says "Dammit, that’s what I wanted!"

        Or you meant bosons, not fermions.
  • Gotcher 11.9 inches right here.

  • And no one has mentioned outfitting these on friggen sharks yet?

  • No need to feel inferior; it turns out twelve inches is more than enough to satisfy Dame Nature.

  • *pew* *pew* ... frickin' ray guns!!

    Now, bring me some sharks!

  • by Anonymous Coward

    Electrons travel at nearly the speed of light already at very low energies. I don't understand why people keep comparing to the speed of light, because getting to 99.99% of the speed of light is the easy part. Its the energy that counts, not the speed.

    The plasma wakefield accelerators are indeed very promising, but are not yet able to replace traditional syncrotrons. For the sake of the field, its very important that a breakthrough occurs b/c even if the Chinese project magically gets funded, there is no po

  • And turn it into an expanding cloud of plasma a few picoseconds later.
  • Michael Litos and his team were able to accelerate bunches of electrons to near the speed of light

    "Near the speed of light" is not a particularly informative phrase when you're talking about particle colliders.

    90%? 99%? 99.9999%?

  • 17 miles = 27.3 km
    49 miles = 78.8 km
    12 inches = 30.5 cm

    You're welcome.

    • Sorry, centimeters are a legacy SI unit, the csg system is obsolete. Get with the times, gramps. Also, you are claiming three digits of metric precision from two digit imperial units, your conversions are incorrect.

  • We got a little frisky the other night, and when she reached down and asked "what's this", I told her it was a 12" super collider.

  • Let me know when they get the price down to $5 and I'll buy two.

If I'd known computer science was going to be like this, I'd never have given up being a rock 'n' roll star. -- G. Hirst