BBC news article
I don't think it's a big deal. There was probably a leak of liquid helium that caused one of the magnets to quench. Hopefully it can be repaired without having to warm the section up.
Isn't this the kind of thing that can be caused by a black hole?
Or that silly string stuff they were talking about.
If anyone takes the above seriously please seek immediate medical attention.
Edit I mean in my post.
Or that silly string stuff they were talking about.
If anyone takes the above seriously please seek immediate medical attention.
Edit I mean in my post.
Magnets do not quench .... it's just the liquid helium gets hot and turns into gas - not surprizing with all the energy fukking about in that kit.
....Last I heard is that the problem stems from a faulty electrical connection which burned magnets....the LHC will be out of commission for several months as they slowly warm the damaged area for repairs.
......according to the sources I used for this report.
......according to the sources I used for this report.
QUOTE (prometheus+Sep 20 2008, 12:18 PM)
LHC halted for months
No wonder ubavontuba hasn't shown up in three days. He booked a flight to Switzerland.
No wonder ubavontuba hasn't shown up in three days. He booked a flight to Switzerland.
A quench happens when the super conductive electromagnet becomes normally conductive. Loss of super cooling would be detected long before a quench actually happened. A quench is an indication that the proton beam or its ejected quanta actually contacted the electromagnet and heated it. This latest incident at the lhc may be an indication that it is far more difficult to keep such a powerful beam running down the middle than originally thought.
But it is big science at it's grandest, eh? It is a truly magnificent collaboration and the physical representation of humankind's most humble interrogative "what is the universe"?
But it is big science at it's grandest, eh? It is a truly magnificent collaboration and the physical representation of humankind's most humble interrogative "what is the universe"?
A quench is not necessarily an indication of steering failure.
The magnet may have drawn too much current for a number of reasons.
The magnet may have drawn too much current for a number of reasons.
When the super conductive quits being so, there is a big problem. The super saturated field and current maintaining it has to go somewhere. The place it wants to go is the warm spot in the electromagnet. This is the exact place we cannot let it go. We have to shunt off the maintaining current and the current from the field collapse to something less expensive than the electromagnet. It did not draw too much current, it rather went resistive and used all the current to make enough heat to melt everything it could.
I stand clarified, thank you. 
You are correct, it's not likely a steering problem. But a bad connection or cooling problem would have indicated at commissioning. Things go wrong catastrophically for reasons that are not obviously apparent. But when they do it while the beam is on.......then I wonder and extrapolate.
All you are hoping on Lhc, not making anything. Therefore gods have given you some more months for independent work.
QUOTE (buttershug+Sep 19 2008, 10:08 PM)
Isn't this the kind of thing that can be caused by a black hole?
Or that silly string stuff they were talking about.
.
Probably a couple of black holes got loose...
It will take a couple of months to locate them...
Not to worry....
Its usually pretty easy ....simply track down the neighborhoods that have reported a few missing children, cattle mutilations, and bright (UFO type) lights in the streets....and start searching there.
JW
Hey, why should all the loons have all the fun getting all the credit for starting nasty rumors?
Or that silly string stuff they were talking about.
.
Probably a couple of black holes got loose...
It will take a couple of months to locate them...
Not to worry....
Its usually pretty easy ....simply track down the neighborhoods that have reported a few missing children, cattle mutilations, and bright (UFO type) lights in the streets....and start searching there.
JW
Hey, why should all the loons have all the fun getting all the credit for starting nasty rumors?
When a superconducting magnet loses its coolant, things look very bad, because the energy stored in the coil exceeds by far the energy needed to vaporize the cooling helium.
In other words: Bang. Loud.
I read at bbc that about 100 magnets went resistive. I just wonder how much of the tube section still exists. It wouldn't be surprising that the magnets destroyed all the surroundings.
Just for fun: the energy density (J/m3) of a magnetic field is 0.5*B^2/mu (mu=1.26e-6) and superconductors are used to go beyond 2T. For reference, explosives pack about 10MJ/kg. Enjoy.
What's a bit unexpected is that 100 magnets went bang at the same time. I mean, people and safety automats know as soon as the first one is out of work. Did the magnets destroy another, or had they a common reason?
In other words: Bang. Loud.
I read at bbc that about 100 magnets went resistive. I just wonder how much of the tube section still exists. It wouldn't be surprising that the magnets destroyed all the surroundings.
Just for fun: the energy density (J/m3) of a magnetic field is 0.5*B^2/mu (mu=1.26e-6) and superconductors are used to go beyond 2T. For reference, explosives pack about 10MJ/kg. Enjoy.
What's a bit unexpected is that 100 magnets went bang at the same time. I mean, people and safety automats know as soon as the first one is out of work. Did the magnets destroy another, or had they a common reason?
QUOTE (Enthalpy+Sep 21 2008, 07:28 PM)
In other words: Bang. Loud.
What's a bit unexpected is that 100 magnets went bang at the same time.
Would that be the Big Bang....or just the little Bang.??
So it was the Loud Bang that stopped the search for the Big Bang.? BTW, there was a large leak of helium....Hmmm...about 1 ton into the tunnel...
http://www.nowpublic.com/world/lhc-big-ban...ine-forced-halt
...
Superconducting magnets such as MRIs and the LHC are not fun in the event of a quench, especially in a confined space.
In this case a poor connection caused a transformer to shut down. This caused a catastrophic leak of a ton of liquid Helium, which would immediately have formed a vapour cloud of some 600,000 litres of gas. A serious Oxygen deficiency would have developed in the area, so it's lucky no one was asphixiated.
I was involved in a similar situation at SLAC where it was discovered the wrong type of Oxygen sensor had been installed which indicated higher Oxygen levels in the presence of Helium, than were in fact the case.
http://www-group.slac.stanford.edu/esh/haz...ic/policies.htm
In this case a poor connection caused a transformer to shut down. This caused a catastrophic leak of a ton of liquid Helium, which would immediately have formed a vapour cloud of some 600,000 litres of gas. A serious Oxygen deficiency would have developed in the area, so it's lucky no one was asphixiated.
I was involved in a similar situation at SLAC where it was discovered the wrong type of Oxygen sensor had been installed which indicated higher Oxygen levels in the presence of Helium, than were in fact the case.
http://www-group.slac.stanford.edu/esh/haz...ic/policies.htm
The LHC access controls are very good. It is nearly impossible for anyone to have been anywhere near the beam path during operation. By the by, the beam was on at the time of the quench. More interestingly, the heating was seen in many electromagnets along section 34. More importantly, vacuum integrity seems to have been lost at the same time. Sounds like a proton stream lost its way and punched several holes in the works. There is no doubt it will take some time to repair, re-cool and re-power the LHC.
I would love to know more! This is a topic of great interest at my place, too.
Unfortunately, our reporter is away someplace out of the US...
Unfortunately, our reporter is away someplace out of the US...
Yes. They take the winters off at LHC. So what is about 2 months of schedule slip is about 6 months of calendar slip.
I think they were hoping to get some collisions before the winter break to give them a chance to start calibrating the machine. Hopefully they'll be able to spend the time thoroughly checking to make sure there are no similar setbacks in the spring.
What better way to clear the streets of snow than to plow them with a high-energy beam!
QUOTE (excaza+Sep 23 2008, 07:38 PM)
What better way to clear the streets of snow than to plow them with a high-energy beam!
Are you nuts!? Do you really want to risk the safety of the earth just to clear some snowy streets?!
Are you nuts!? Do you really want to risk the safety of the earth just to clear some snowy streets?!
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