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LHC will only operate at half power to try to detect problems earlier

The Large Hadron Collider may usher in a new era of particle physics as the world's most powerful particle accelerator.  However, the LHC has also been the victim of numerous delays, ever since its launch last September failed. 

At launch an electrical fault between two of the magnets reportedly caused an arc of electricity, which in turn triggered a helium leak and explosion.  As a result, the proton tube was contaminated with soot, and the magnets were broken off from their mountings.  Months of repairs revealed more leaks in the vacuum of the insulating layer surrounding the proton tube.

Now the European Center for Nuclear Research, or CERN has declared that the repairs are done.  States CERN in a press release, "[Tests] will initially run at an energy of 3.5 TeV per beam when it starts up in November this year.  This news comes after all tests on the machine's high-current electrical connections were completed last week [the week of July 27], indicating that no further repairs are necessary for safe running."

Still, the restart represents caution on CERN's part -- 3.5 TeV is only half of the beam's full intended operational power.  States CERN Director General Rolf Heuer, "We've selected 3.5 TeV to start because it allows the LHC operators to gain experience [with] running the machine safely while opening up a new discovery region for the experiments."

There remain concerns about whether the device is capable of running at full power.  Describes CERN:

Following the incident of [Sept. 19, 2008] that brought the LHC to a standstill [due to a faulty magnet connection], testing has focused on the 10,000 high-current superconducting electrical connections like the one that led to the fault. These consist of two parts: the superconductor itself, and a copper stabilizer that carries the current in case the superconductor warms up and stops superconducting, a so-called quench. In their normal superconducting state, there is negligible electrical resistance across these connections, but in a small number of cases abnormally high resistances have been found in the superconductor. These have been repaired. However, there remain a number of cases where the resistance in the copper stabilizer connections is higher than it should be for running at full energy.

However, CERN also says that it has tested and repaired a large number of these faulty copper connections.  It says that the final two sectors it tested revealed no abnormalities.  Nonetheless, after all the headaches, it plans to throttle up the 17-mile long accelerator loop slowly, just in case there's still undetected problems.



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RE: better safe than sorry
By Hammer1024 on 8/11/2009 4:51:57 PM , Rating: 2
Cosnic Rays in the wild hit up to 10^20th electron Volts; 10 with 20 zeroes behind it.

The Tevatron, outside of Chicago at Fermi Labs, hits around 10x12th eV (1 TeV) while the LHC, maxed out in it's launch configuration, is 7 TeV or 7x10^12 eV...

Last time I looked out the window, the earth hasn't been swallowed...

So if the LHC can generate black holes, they've been being generated over your head for the past few billion years or so.

I've got better things to worry about.


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