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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 SpaceJumper on 8/11/2009 6:10:39 PM , Rating: 2
I put it in a simple term so people can understand. The mass is accelerated to near the speed of light, E=mC^2. The energy is converted to mass, it is like an orange with a hyper thick skin. During collision, some of the orange skins will be separated from the orange and landed onto the detectors.
If the particles are not magnetic then the particles should not be responding to the magnetic fields. Are you implying that the Maxwell's equation is wrong.
LHC is still in the religious stage.


RE: better safe than sorry
By MrPoletski on 8/12/2009 4:41:54 AM , Rating: 2
quote:
I put it in a simple term so people can understand.


Please don't, because it makes no sense!

quote:
The mass is accelerated to near the speed of light, E=mC^2. The energy is converted to mass, it is like an orange with a hyper thick skin.


Now the binding energy inside an atom uses the mass-energy equivelance equation you quoted... but in terms of the objects kinetic energy e=mc^2 has nothing to do with it.

quote:
During collision, some of the orange skins will be separated from the orange and landed onto the detectors.
If the particles are not magnetic then the particles should not be responding to the magnetic fields. Are you implying that the Maxwell's equation is wrong.
LHC is still in the religious stage.


About that magnetism thing. A particle can be magnetic only in that it has an electric charge distribution across itself and it is spinning. Iron atoms are all little magnets because the atom spins and the electrons around it do not form an even charge distribution across it. At any given time there may be more charge at one side of the atom than the other. Wan der waals bonds in metals uses this principle IIRC. Anyway, magnetism is created by the motion of an electric charge, nothing more and nothing less. Charged particles experience a force due to a magnetic field - directly proportional to their velocity - because when they move, they actually create their own magnetic field which interacts with the one that is, apparantly, impartng force on the charged particle.


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