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LHC's 'Heart' Starts Pumping Protons Before Restart

Posted by Soulskill on from the pumped-up-to-crash-particles dept.

astroengine writes: While on its long road to restart, yet another milestone was reached at the Large Hadron Collider (LHC) over the weekend. Protons were generated by the LHC's source and blasted through a "daisy-chain" of smaller accelerators before being intentionally smashed into a metaphorical brick wall. The particle beam didn't reach the LHC's famous 17-mile (27-kilometer) accelerator ring — they were stopped just short — but the event was used to begin calibration efforts of the massive experiment's detectors before the whole system is powered back up again early next year. "These initial tests are a milestone for the whole accelerator chain," said the LHC's chief engineer, Reyes Alemany Fernandez. "Not only was this the first time the injection lines have seen beams in over a year, it was also our first opportunity to test the LHC's operation system. We successfully commissioned the LHC's injection and ejection magnets, all without beam in the machine itself."

23 of 50 comments (clear)

  1. Re:Heart starts pumping.. by Anonymous Coward · · Score: 1

    Congratulations, you're an idiot. Well done.

  2. Dry firing by Slagothor · · Score: 1

    Wouldn't a dry fire stress the components more? I mean, we are not talking about toy magnets. I guess they've determined that it is completely acceptable so I will certainly defer to their judgment. I need to read up some more on its power generation and magnetic systems.

  3. Re:Heart starts pumping.. by Thanshin · · Score: 3, Informative

    I know, right. Also, can we get some Americans in charge of that thing?

    Are there Americans under the age of about 35 who have studied enough physics to even know what a particle collider is?

    Or you meant put American immigrants in charge of the big toy.

  4. Re:Heart starts pumping.. by dbIII · · Score: 3, Insightful

    The experiments break stuff and it takes years to rebuild it.
    In a lot of cases that's what science is - a lot of hard work over a long time for a few hours of experiments.

  5. Hawking radiation by dbIII · · Score: 1

    Funny how everyone has heard of Hawking and knows he's famous but there's still a popular perception that little black holes are going to last longer than an eyeblink and become big ones.

    1. Re:Hawking radiation by ceoyoyo · · Score: 1

      All the diagrams I've seen are from the perspective of an observer falling into a static black hole, with the mass concentrated as a singularity in the centre. For the outside observer, it takes infinite time for something falling in to cross the event horizon.

      So suppose black holes actually do evaporate. An infalling observer could find the event horizon retreating from him as the hole shrank.

    2. Re:Hawking radiation by Anonymous Coward · · Score: 1

      So suppose black holes actually do evaporate. An infalling observer could find the event horizon retreating from him as the hole shrank.

      Not unless that black hole evaporates on the timescale of a a few seconds, as seen by a far away observer. Look up a Eddington-Finkelstein diagram, where you have clear indication of light rays from infinity coming in, and can be thought of as regular pulses from a distant clock. The infalling observer still reaches the center on a very short timescale compared to both the the outside and their own clock. To find away for the infalling observer to miss the event horizon of a stellar sized or larger black hole due to evaporation, you would have to reach beyond GR.

    3. Re:Hawking radiation by dbIII · · Score: 1

      Not unless that black hole evaporates on the timescale of a a few seconds

      Much less than that unless you can collapse the mass of a small moon into a black hole.

    4. Re:Hawking radiation by dbIII · · Score: 1

      A black hole with that much mass is going to take a lot more than the LHC to get it going.

    5. Re:Hawking radiation by ceoyoyo · · Score: 1

      I'm not a physicist, so if I've made a mistake I hope someone can point it out.

      Eddington-Finkelstein coordinates reparameterise the Swartzchild coordinates (t,r,thea,phi) with (v,r,thea,phi) where v = t + r* and r* = r + 2M log(r/2M -1). Note that r* -> -infinity as r->2M so as r->2M v -> t + infinity. For an outside observer, the ticks of a clock at the event horizon are infinitely far apart. Similarly, dt/dr -> infinity as r->2M.

      From another perspective, for an outside observer we're not interested in infalling light rays, we want to know about escaping ones. Pulses emitted from an infalling light clock will appear to us to be farther and farther apart (and more and more redshifted) until they are infinitely far apart at the horizon.

      From the perspective of the outside universe, it takes an infinite amount of time for anything to reach the event horizon. A black hole that evaporates on any timescale for an observer at a distance should have an event horizon that retreats from anything infalling.

      There does seem to be a conflict between the outside observer and the falling one. It seems to me this is resolved in much the same way the twin paradox is in special relativity. If the infalling observer were to stop just before the event horizon and return to the outside observer, he would find that, while accelerating away from the hole, the outside universe was enormously blue shifted, making up for the blue shift he did not observe while falling inward. When he met up with the outside observer and compared notes he'd find that his clock had been running much slower.

      In another way of looking at it, to the infalling observer the universe behind him is accelerating away and he would expect it to be redshifted, but it is not. The universe on the other side (light skimming the event horizon for example) IS enormously blue shifted.

  6. Missing the real news here by wonkey_monkey · · Score: 3, Insightful

    before being intentionally smashed into a metaphorical brick wall.

    Surely the real news here is that they've been able to make functional use of abstract concepts.

    Next they'll announce that they've slashed the electricity bill by powering the magnets with love.

    ---

    The article could have told us what the protons were actually smashed into, instead...

    --
    systemd is Roko's Basilisk.
    1. Re:Missing the real news here by CaptainLard · · Score: 1

      No, the real news here as far as /. is concerned is that pretty much every knowledgeable user is gone.

      These stories used to take off and have comments that genuinely added to the article by actual scientists and sometimes even people working on the project. Now they struggle to get 50 comments where half are trolls, 1/4 are weak jokes, 1/8 are armchair physicists quoting junk science, 1/16 were trying for first post in a different article and the remainder is divided up into legitimate questions and responses. The numbers probably aren't all that different but apparently the informed user base has dropped below a critical mass. Its too bad because as the LHC shows, when we learn new things these days its on the grandest scale. If anyone has suggestions on where to go for such insight please let me know. /. can shine on as a repository for political circle jerking, shills, and (in far greater numbers) accusers of shills.

      Oh, and to answer your question*, the metaphorical brick wall is actually "21.6 tons of graphite, aluminum and copper known as “beam dumps." - source: the article

      *Note: In my rant I didn't bash the /. tradition of not RTFA. Thats the glue that holds us together.

    2. Re:Missing the real news here by Anonymous Coward · · Score: 1

      As an actual scientists working in a related field, I find this article is pretty boring and mostly hype. It is not that the work being done is unimportant, but it is one step short of a "everything is okay alarm." It is good things are still working, and yes progress is being made, but this isn't a big milestone or much in the form of news, even for many people in the field.

      Slashdot has always had a lot of junk science and trolls in science articles. Things have gone downhill slightly, but is not crossing some sort of critical mass threshold in general (each person on the other hand may have their own cumulative BS threshold, which is why I left over sites). In some sense, it seems the general masses provide some buffer, as places that were much more science-centric with a lot more attention from knowledgeable people also get flooded with crackpots a lot quicker.

  7. Hydrogen atoms by TropicalCoder · · Score: 1

    From the FA: "hydrogen atoms are stripped of their electrons, leaving the positively-charged protons behind". So I wonder where they get the hydrogen atoms? Hydrogen doesn't like to exist in atomic form. It much prefers company, in the form of H2. I don't think you can have a bottle of hydrogen atoms, as opposed to hydrogen molecules. Ionizing hydrogen molecules does not break apart the molecules, I wouldn't think. Maybe the article misspoke?

    1. Re:Hydrogen atoms by Anonymous Coward · · Score: 3, Informative

      I googled "Proton source", image search, and this popped up:
      http://blog.vixra.org/2011/05/29/new-luminosity-record-for-lhc/

      At first glance a nice overview. This picture http://vixra.files.wordpress.com/2011/05/proton-source.jpg is your source. See the bottle of hydrogen there? :)
      It says "Linac 2" in the background, the first accelerator at Cern, for protons.

    2. Re:Hydrogen atoms by TropicalCoder · · Score: 1

      Oops. That was me. It appears that clicking on the "You are posting as" check box works backwards to what is intuitive. In fact, that is a funny UI, where there is what appears to be a check box to post by your account name, and a little gear symbol to post as Anon. I would expect standard radio buttons instead of this original invention. Maybe Web UI has different conventions then software? Can't be. This UI makes no sense and is unintuitive.

    3. Re:Hydrogen atoms by DMUTPeregrine · · Score: 3, Informative

      Ionizing hydrogen DOES break apart the molecules. The molecules are held together by their electrons, removing those breaks the bond.

      --
      Not a sentence!
    4. Re:Hydrogen atoms by ceoyoyo · · Score: 1

      Ionizing H2 will absolutely break apart the molecules. You know that atomic bonds are made by the electrons, right? Two protons really don't like to be anywhere near each other unless there are electrons and/or neutrons involved.

  8. Re:Heart starts pumping.. by PPH · · Score: 1

    It's alive!

    --
    Have gnu, will travel.
  9. Re:Heart starts pumping.. by werepants · · Score: 1

    Most particle accelerators spend a good portion of their time in maintenance, perpetually, and that includes American ones. The cyclotron at Texas A&M, for instance, is closed for the first quarter of the year, every year. And that isn't even a facility that is new and still gearing up - it has been running that way for many decades, yet it still requires that much downtime.

    So stop being a nationalistic douchebag. But who am I kidding, I'm responding to an AC here.

  10. Re:Heart starts pumping.. by werepants · · Score: 2

    Hey, OP is a nationalistic idiot, but responding with more nonsense generalization doesn't fix things.

    I happen to be an American, under 35, with a degree in physics, who occasionally works at particle collider facilities. The average state of scienctific literacy might not be fantastic here, but there's no denying that many of the best minds in physics today are from the U.S.

  11. Re:Heart starts pumping.. by RubberDogBone · · Score: 1

    This is 'merica. In 'Merica, we don't accelerate protons around a track. We accelerate the track around the protons.

    This just takes Texas-sized amounts of time.

    --
    Sig for hire.
  12. Re:Heart starts pumping.. by RubberDogBone · · Score: 1

    there's no denying that many of the best minds in physics today are from the U.S.

    Maybe so but it is approaching midnight on that day and things will change soon.

    --
    Sig for hire.