Saturday, December 6, 2008

CERN in the news

This article by Dennis Overbye of The New York Times gives an update on when the LHC is going to start back up. They say that they could be doing a more limited series of collisions by next August, but won't be up to full power for some time after that. Some say this is an optimistic timeline.


If you saw our film, you remember Ben Kilminster near the end, wearing his Batman T-shirt, re-iterated that Fermilab and Cern were in "kind of a bit of a race" to find the Higgs, and that they needed CERN to "trip a little bit --- stumble."

What ended up happening was not just a trip but an all-out head-over-heels tumble. A quick recap: in order to get the protons to go in a circle instead of in a straight line, CERN (and Fermilab) use gigantic magnets to bend their trajectory. How big are these magnets? Each one weighs ... ten tons. (that long orange thing in the picture is one of them...

in fact, one made at Fermilab and shipped over for use at CERN! See how cooperative they are in their competition?) There are a staggering 1,232 of these magnets. And in order to get them to be really efficient, they cool them way down, to 2 degrees above the temperature of deep space (absolute zero). This makes them "superconducting."


How do they cool them down? With liquid helium, naturally. Really cold stuff.

So, they think an electrical problem caused a spark which punctured the layer of liquid helium, causing it to flood out and expand (when liquid helium under pressure turns into a gas it practically explodes). I'll quote from the article:

The resulting internal pressures shoved some of the magnets off their mounts and crunched the connections between them. The beam pipes that the protons shoot through were also punctured and contaminated with soot. Or as Dr. Gillies said, "It's a mess."

Remember, those magnets weighed 10 tons!

So, they've got a major workload on their hands. As the article says, they have to bring no less that 53 of those 10 ton magnets to the surface (they're 300 feet underground) to inspect them and fix them, and then do tons of checking and evaluating of the whole darn thing.

Good luck, CERN! In the meantime, Ben and company are working away at Fermilab, regretting the difficulties their colleagues in Europe are having (and trying not to rub their hands with glee too much).

1 comment:

Hi Kooky said...

Holy cow. I'll bet that brought a few stoic scientists to tears.