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Europe's LHC To Run At Half-Energy Through 2011
quaith writes "ScienceInsider reports that Europe's Large Hadron Collider will run at half its maximum energy through 2011 and likely not at all in 2012. The previous plan was to ramp it up to 70% of maximum energy this year. Under the new plan, the LHC will run at 7 trillion electron-volts through 2011. The LHC would then shut down for a year so workers could replace all of its 10,000 interconnects with redesigned ones allowing the LHC to run at its full 14 TeV capacity in 2013. The change raises hopes at the LHC's lower-energy rival, the Tevatron Collider at Fermi National Accelerator Laboratory in Batavia, Illinois, of being extended through 2012 instead of being shut down next year. Fermilab researchers are hoping that their machine might collect enough data to beat the LHC to the discovery of the Higgs boson, a particle key to how physicists explain the origin of mass."
Does this news mean we now only have to be half afraid that they're going to create a black hole that will destroy the Earth?
at (apparently) no one being fired for designing interconnects that only allow the LHC to run at 1/2 power? I may not be a scientist, but shouldn't a design cover the requirements? Then, to lose a year's work on top of that, and no one is getting their wrist slapped or even sued?
Impetuous! Homeric!
7 TeV is still more than 3 times Fermilab's total collision energy.
This more conservative ramp up is probably smart given the previous problems with equipment failure on the LHC. This will allow the systems to be tested thoroughly before going to max capacity.
I'm scared for all the half-lives at risk.
But what about all the counter-strikes and the portals?
The Big Deal about the LHC isn't just the energy. It's also that it allows for a much higher collision rate than the Tevatron. Even if you only run the thing at Tevatron energies, it's possible that it can collect as much data in a week as the Tevatron could in years.
When the LHC guys down the hall show up tomorrow I'll have to ask them about the planned luminosity in the first year of running.
Uh, HEL-LO?!! Have you guys forgotten that the world is going to end in 2012?!! I think you might want to ramp it up all the way in 2011...just in case.
"Klaatu, verada, necktie!" -Ash
Maybe they can claim that it has to do something with global warming and the giant sound of sucking machines, and micro-black holes will start getting the money for them.
Om, nomnomnom...
And hyperdrive.
When you're afraid to download music illegally in your own home, then the terrorists have won!
It certainly would have been possible to design them with a higher safety factor, but that would have increased the cost...Unfortunately for a large cutting edge project on a tight budget, you need to take some technical risks.
I seem to have heard this argument before.
The Apollo fire. The loss of the Challenger. Repairs to the Hubble.
If the LHC was designed properly, run the friggin' thing. If not, fix the friggin' thing.
Did you RTFA? That's exactly what they're doing. It takes time to come up with a proper fix, but while you're coming up with something, why not use the thing? Even at a fraction of its energy, the LHC is the most advanced accelerator in the world. It would be a shame to just let it sit there.
The beam energy at 7TeV is 362 megajoules. This is about the energy that you could get by maxing out a household mains connection (230V 20A) for one day, or about the energy content of 11 liters of gasoline. Quite a bit, but not huge at energy scales.
Of course, the beauty of the LHC is that it accomplishes this energy in the form of a particle beam circling the collider at near the speed of light. This means that the power of the beam is about 4 terawatts if my math is right, so it could power about 3300 DeLorean time machines (not for very long, though). Keep in mind that this power is circling endlessly in the LHC, so it isn't being consumed - the actual electric power consumption to run the whole LHC is "only" about 120 megawatts.
If the LHC was designed properly, run the friggin' thing. If not, fix the friggin' thing.
Did you RTFA? That's exactly what they're doing. It takes time to come up with a proper fix, but while you're coming up with something, why not use the thing? Even at a fraction of its energy, the LHC is the most advanced accelerator in the world. It would be a shame to just let it sit there.
Without even counting that running it will stress some other hardware and uncover some other potential problems.
IIRC, the bird dropped its bread on something a little more innocuous sounding than a reactor. The bird escaped unharmed but lost its bread.
Hard to get all worked up about this when the people running the program don't seem to be concerned about accomplishing anything significant. Sort of like spending untold billions on a supersonic aircraft, and after all the money is spent, flying it subsonic for a year or so, and then grounding it for another year to re-wire it.
Well, no. It sounds like they're quite concerned about doing something useful after spending those billions of euros. They still have the most powerful particle accelerator on Earth by a good margin, even if it's not up to its full design power (yet). They can do some solid science, good experiments, collect a year's worth of data and test all of their detectors and other hardware.
After that, they'll have a year with the beam turned off, in which they can actually analyze the mountains of data that were generated during a year of experimental runs. In addition to replacing the magnet interconnects, experimenters will have a year to fix any problems that come to light with detectors and other experiment hardware and software. This period of operation means that there shouldn't be any unpleasasnt surprises when they do go to full power, because they'll have had a year of 7 TeV operation to shake out all the bugs.
~Idarubicin
In an equally optimistic point of view, if Higgs boson is later shown to not exist, the Tevatron Collider can claim that it was able to not find it before the LHC!
Fellow Slashdotters, I hope is becoming abundantly clear by now that an age is ending; the great 20th century scientific projects are fading into history, and the 21st century will require us to dramatically lower our expectations for scientific civilization. What exactly is the payoff for the LHC anyway? In what way does it inspire society at large or contribute anything useful? It’s very strange to be living through the collapse of your own civilization, but with each passing day it becomes more and more clear to me that that’s what is happening. It looks to me like our resources are going to be funneled increasingly toward the military as we struggle to maintain what we already have, instead of pursuing inspirational projects that ordinary people can understand. A sad time to be alive for those of us who grew up with bigger dreams, but maybe it wasn’t meant to be.
and only dropped half
The failures, or rather misdesigns/misbuilds, are in "copper bus bars". These effectively act as shorts across the superconducting electromagnet coils. Since the coils are normally superconducting (when at cryogenic temperatures), the short does nothing. But if the coil gets ever so slightly above its critical temperature, it ceases to be superconducting. At that point, it still has very very low resistance, but the current through it is so enormous that it heats up rapidly. When it gets to a certain temperature, its resistance becomes comparable to the resistance of the copper bus bar shorting it, and the current starts to flow more and more through the copper, thus protecting the superconductor from getting too much hotter. At least, that's what is supposed to happen.
What is wrong is that some of the solder joints for the bus bars are not good, and have too high of a resistance. A higher resistance in the bus bar system means a higher superconductor temperature before the current starts to flow through the copper, and in the end, this means damage to magnets.
I'm not sure what level of testing was done, but building a short segment and testing it up to slightly above design spec is probably not really feasible. In order to get the particles to the eventual energies, you need the whole ring to be in working order, because it takes tons of complete circles around the ring to accelerate the particles. Injection from the SPS to the LHC occurs at 1/14th the design beam energy, and the LHC ring takes it up from there.
Even if you could inject 7 TeV protons into a short segment of the ring, you'd still not be able to get the design beam intensity that way, because you don't have all 2000+ bunches ready for injection at once.
You could run the magnet intensities up to what is needed to bend a beam in a tight enough circle at high enough energies even without any actual beam in there, and this was probably done. However, quenches (magnets getting above critical temp) happen principally because of the beam. The beam loses particles and energy at a fairly high rate due to a variety of effects, and all those particles and all that energy goes into heating something, usually the bending magnets. I suppose you could do a deliberate quench by playing with the cryo, though. Perhaps that was done, and we were unfortunate enough to have tested only good subsystems this way.
As you may have guessed, I am a particle physicist (on CDF), but not a beams engineer. So, some of the above is guesswork, but I hope I've been able to relieve some of your ignorance.
SIGSEGV caught, terminating
wait... not that kind of sig.
Thank you very much, you explained it well and I understand more now.
Wouldn't a quench have a huge back-EMF associated with it as the field collapses? I don't see any alternative but for much of that energy to go through the coil-bar circuit and heat the coil up more.
Bruce Perens.
Because the two machines operate at different collision energies. The Higgs cross section is going to be different at each collider due to this energy difference, so when you go to measure this cross section you're going to get different results.
You can perform a meta-analysis, whereby you make a "best measurement" at different colliders and energies in order to better understand the measurements. However, that's not what you're proposing; you're proposing that they combine data in order to get a result in the first place, which you can't do.
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LHC Feed @ Feed Distiller
Nice to see that when something goes wrong, it becomes 'Europe's' LHC. I thought CERN was an international thing.
I think it reasonable to expect taxpayers to get something back from it
You mean like the computer you wrote your post on? The medicine that has roughly doubled life expectancy in the developed world in the past few hundred years or so? What you seem to be advocating is akin to the recent UK government plans to assess potential economic benefits of research before granting funding which has met with considerable opposition. Private enterprise is certainly well-equipped enough to make a profit for the economy by applying the findings of fundamental research. Take the iPod for example. This needed research into materials, solid state physics, batteries etc, much of which would have been done at a government subsidised university/insitution. Private enterprise stands on the shoulders of giants and provides the economic benefit that easily justifies subsidising pure research.
"There is nothing which can better deserve our patronage than the promotion of science and literature. Knowledge is in every country the surest basis of public happiness."
-George Washington (address to Congress, 8 January, 1790)
Are you serious? None of those more useful things you listed would be here without, say, nuclear physics. Scanning microscopes, NMRI, VLSI... heh.
Tsunami -- You can't bring a good wave down!
Yup, synchrotron radiation. This is significant with electron accelerators, but the LHC accelerates heavy ions where it isn't that much of a problem. The synchrotron power emitted is about 3.7kW in total.
While it's a shame that all the money put in so far hasn't quite led to the promised results, it doesn't matter. It's sciency, and it's worth it at any price.
timothy
jrnl: http://tinyurl.com/c2l8yr / foes: http://tinyurl.com/ckjno5