Superfluid leak downs LHC for months Bad news broke at the weekend for fans of the Large Hadron Collider (LHC) - the titanic underground magno-doughnut proton punisher located outside Geneva. Technical mishaps will mean at least a two-month delay before the inaugural hadron headbang. It appears that problems arose after a faulty electrical connection between two …
Tim Berners-Lee invented the world wide web only because he didn't have anything to do. Now, thanks to Mr Berners-Lee, they will just spend the next few months doing what the rest of us do when we have nothing better to do at work. Looking in to the finer points of his invention, or as its otherwise know, wasting time on the net.
If anyone wants to know what's REALLY going on at the alleged LHC, read Akira. You'll get a good idea of why they need all that supercooled helium, and what happens when it escapes and covers everything/everyone in the vicinity (with a little artistic licence, maybe).
Mark my words: When small silent Japanese children start wandering around the Franco-Swiss border, start getting worried. And if they start wailing 'oooow-ow-ooow' and fall over with a heart-pounding 'DO-DOM' noise, kiss your arse goodbye; colliding protons have nothing on the psycho-telekinetic explosion that will follow, wiping out Geneva and leaving it as a post-apocalyptic cult-led state...
Helium's a bugger to confine - which is why it's useful as a leak tester - without cooling it to super-fluid levels, at which point it becomes EXTREMELY difficult to contain, even in a 'closed' system.
About the only way you'd realise it was leaking would be when gaseous helium started appearing in the secondary containment, which is, I assume, monitored for just such an event. Certainly no risk of asphyxiation, or 'Donald Duck' there though, it's not an area where life could be sustained anyway.
Bummer. There I was waiting to see what actually happened... So, now a few months wait for 'Universe 2 - the Sequel' to be triggered.
In fact, because the leak seems to have been caused by a couple of magnets suffering 'mechanical issues' due to an electrical element melting - i.e. the temperature differential caused the cooling system to develop a leak (read 'crack'), this could stall the attempt to end the original universe for some considerable time. A year possibly.
Hope they have plenty of spare magnets, this could be an ongoing problem. Things cooled to super-fluid temperatures develop some very odd characteristics. Brittle isn't half of it!
"leading to a probable plague of superhero physics nerds pondering whether to use their powers for good or to achieve world dominance." .....
Nice tale, Lewis, but you bottled out on the important bit ..... leading to a probable plague of superhero physics nerds pondering whether to use their powers for good and achieve world dominance.
I Kid U Not? :-)
Ps Don't believe any of those naysayers with their noses in the Establishment troughs..... the Times they have a'changed or haven't you been following the Meltdown.
Genuine superfluid leaks are a bugger to find/sort out.
This sounds like a more your bog-standard magnet quench - caused when a part of a superconducting electromagnet goes into the normal conducting phase. In standard operation these magnet coils will carry an enormous current that just flows around and around without any energy loss. As soon as a small section goes into the normal phase this introduces resistance; resistance plus large current equals heating; heating a superconductor may make more of it go normal...and so you get a chain reaction.
What then effectively happens is that all the energy stored in the magnetic field is dissipated through resistive heating in a very short period of time. THIS causes a very great deal of helium gas to be produced (from your formerly liquid coolant) which needs to be vented from the apparatus pretty quickly or your experiment will get all bent out of shape (literally). So what appears to be a helium 'leak' is actually a safety system working as designed.
My guess is they'll be warming up to check the magnet coils and associated gubbins, not to fix any leaks.
>"... sure that there had been no naughty boffins playing hookey in the affected tunnel segment, and consequently no danger of any superfluid engulfment and/or helium asphyxiation bother ... "
... has anyone heard anything from those blokes who launched the lawsuit since this happened?
>"There's tabloid-style, and there's butchery-of-intellect. This was so far into the latter that I think it might have been intentional.
At least, I hope it was."
And the rest of us hope that El Reg isn't obliged to reintroduce the "JOKE" icon on any story that isn't written in a dull lifeless monotone just for the sake of those who can't spot humour when it bites them on the ass. Please try not to disappoint us further.
'Ere's yer problem mate, this 'ere works been looks like its bin done by Clint & John & Co. - a bunch'o cowboys if you arks me.
s'gunna take a coupla munths to get this back up again, can't get the parts fer these ya know, they stopped makin 'em jus too wiks ago mate, yeah, bad timin' but I fink we got a couple these 'ere coily fings back at me shed, I can givem to yas fer $12,500,000,000 each an thats cuttin me own froat....
Use any accent you want - I can't work out who I was channeling there....
can we get a cowboy icon?
"Even if any bystanders had escaped being turned into frosty stalagmite statues, they might still have suffocated as the helium rapidly evaporated into gas and drove out any air in the vicinity."
Except that when the LHC is "powered up" (you know, that big non-event a couple of Wednesdays back) nobody is allowed into the tunnels. Not in case of lethal helium roaming the area, but because its a little more radioactive down there than the human body normally takes a liking to.
So uh yeah... Research? Comes cheap these days I'm assured...
-- Richard
"It was a quench, but caused by electromechanical failure. They still don't know quite why as the area has not been made safe yet by the fire brigade (need to check for further LHe leaks etc). About 2 tonnes of LHe leaked into the tunnel."
You've arranged a lot of words there without making any actual sense. How you deduce this "certainly" is a superfluid leak remains utterly unclear (in fact it is unclear to me whether you understand the difference between a superfluid leak and a "normal" leak), although I must confess I enjoyed the surreal image of the fire brigade looking for liquid helium leaks. Perhaps they could watch for it dripping out.
The point I was trying to make in my original post was that this incident does not appear to anything to do with a "Superfluid leak" as suggested by the article's title. It's a discharge of Helium from a system that contained superfluid helium at some point, though probably not at the time of the discharge. Furthermore this venting is a function that is designed in to the cryogenic system: see https://edms.cern.ch/file/445856/5/Vol_1_Chapter_11.pdf , page 17, "Resistive transition" - "...The discharge of helium from the magnet cold mass"...
What I don't believe is that you know anything whatsoever about cryogenics. Did you find that design document interesting reading, or was it all just a bit over your head?
There is no mention in this press release of a superfluid leak - which this "certainly is" according to your original post. There is no mention of superfluid at all. In fact the whole thing is entirely consistent with a magnet quench causing heating, boiling and resulting in overpressure in the helium bath, which was then relieved by venting helium gas to the tunnel. That is why "the sector has to be brought to room temperature and the magnets involved opened up for inspection". This could be paraphrased as: "warming up to check the magnet coils and associated gubbins" as I mentioned in my original post, the one you felt so well qualified to contradict.
So yeah, I don't believe you. The fact that you think this press release proves your point - when it does exactly the opposite - only serves to enhance that feeling.
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