Bad Math Causes Explosion at CERN Collider

javipas writes "The Large Hadron Collider at the CERN has suffered a big explosion deep inside that has caused a leak of hellium gas and the quick evacuation of everyone working there. The reason: a mathematical mistake that affected the design of the giant superconductive magnets made by Fermilab. Now the company will have to repair and upgrade the 24 magnets that are installed on the 27 km. circunference of one of the most important research centers on Earth." This story might seem strangely familiar to you.

Comments

Not a Dupe

[Anonymous Coward]

Isn't this the same story as from a week or two ago?

While it may have the same message to you (Big Ass Magnet Fails on Fermilab's Collider at CERN), it's actually the result of an investigation.

From one of the articles in your link:

Fermilab will appoint an external review committee to analyze how this problem occurred and determine root causes and lessons learned.

The old story was that stuff blew up. The new story is why it blew up so we don't make the same mistakes. Turns out it, was just bad math. It wasn't that we didn't understand some physics, it wasn't the gods being mad, it was just plan old avoidable bad math.

A somber and depressing article for the /. community considering how many people have been posting about the huge leaps in physics this machine was supposed to bring us ... hopefully another country will come up with something similar to keep this research rolling while CERN awaits repairs.

Re:Not a Dupe

[bockelboy]

I work on the LHC (although not a particle physicist, I talk to ones every day).

If you had to explain it at an 8th grade level (as newspapers aim for these days), you'd say "bad math". If you are on a nerd site like Slashdot, I'd hope we wouldn't need to make that simplification. The story is a dupe. It is still the same as before - the assymmetrical load was not put into the requirements for the magnets and overlooked during four internal and *external* reviews. CERN had all the right data, and they overlooked that specific test too.

There is a committee reviewing the case, and their findings will be released April 24 (tentatively). FNAL's goal is to have this not delay turn-on at all, although it'll cost some amount of money to fix. They hope the repairs can be made in-ground. The absolute worst-case would be if they have to take the magnets up to the surface to fix them; that will certainly cause a time delay.

Right now, they suspect it's an additional cost, but not a delay for the November turn-on. That picture could get worse, but we won't know until around May.

Lots of the world's top particle physicists have been on this project for many years; any country capable of doign "other" research is certainly already heavily involved with the LHC. The only possible project which will benefit from the delay is the Tevatron at FNAL, but we're probably 18 months from running the LCG at Tevatron levels (it will take *at least* a year to begin to get all the bugs worked out and tunings done to a multi-billion dollar system).

One delay will be noise compared to the amount of effort needed to prove the existence of the Higgs.

Some real information

[gvc]

Here's Fermilab's statment. Of course they are an interested party, but at least their statement contains information, unlike the snide popular press article.

http://user.web.cern.ch/user/QuickLinks/Announceme nts/2007/LHCInnerTriplet.html

Re:NPR Story missed this one

[Waffle Iron]

They mentioned how a particle zooming around in it would have the force of a bus

Not really. The most powerful cosmic ray particles ever observed, which have are millions of times more energy than anything we can create, each have approximately the force of a thrown baseball. Perhaps *all* of the particles in the ring together have the energy of a moving bus.

suffocation

[SuperBanana]

What's so bad about that?

What's bad is that it displaces all the oxygen in the area. This was a common cause of occupational deaths in MRI rooms- not flying metal objects attracted to the magnet (though a very small number of people have been killed by oxygen tanks and such.) An MRI repair tech was killed because of a slow helium leak that lowered the oxygen percentage enough that he passed out. That's why most if not all MRI facilities have gas monitors that monitor oxygen, nitrogen, and helium levels (liquid nitrogen is also used.)

MRI machines have vents for this sort of thing. Also because if the magnet quenches, a LARGE amount of liquid helium will boil off; all the electrical energy used to generate the field, which is constantly running in the magnet, turns very quickly into thermal energy. If the vent wasn't there, the room would pressurize, preventing one from opening doors (even an outward opening door- enough force would make it impossible to overcome friction on the bolt.) Magnet quenches are done only in situations where someone's life is in immediate danger (say, they're trapped by a ferrous object and about to bleed out) because of the danger (and the fact that there's a 1:4 chance of destroying the multi-million-dollar magnet and boiling off thousands of gallons of very expensive liquid hydrogen.)

It's been reported in vent failures when a magnet quenched that it rained oxygen; liquid helium is substantially colder than liquid oxygen. Shit happens: vent valves fail, birds nest in stuff, someone says "hey, what's that big empty pipe for" 6 rooms over and cuts it/blocks it off, etc. I think the MRI tech was killed because of a leaking o-ring.

Are they just afraid no one will take them seriously if they sound like the chipmunks when they report their findings?

Picture one guy yelling "Run, run! We'll all suffocate!" in a chipmunk voice, and everyone else laughing at how funny he sounds, and passing out. And dying.

I mean, it's not like it's spraying O2 in the direction of the pilot light of their oven.

Oxygen spraying in the direction of a pilot light in an oven will do nothing except make the pilot light burn at a higher temperature. It will not cause an explosion, because there's nothing else combustible in the oven, unless it's REALLY greasy.

What is not a joking matter is smoking in high-oxygen environments or fires in spacecraft, because they do have lots of flammable stuff, like wire insulation (which is fire-resistant, not necessarily fire-proof.)

Re:NPR Story missed this one

[HoldenCaulfield]

The relevant quotation from the story on NPR:

"It's the energy of a bus moving at a normal velocity," De Rujula says. So imagine a bus rolling along -- which has something like 10,000 trillion, trillion particles -- but transfer all that energy into one single particle. There will actually be a beam of protons; a whole fleet of subatomic particles, each carrying the energy of a bus.

In other words, the grandparent just mis-remembered the story, or didn't realize how important the distinction could be when talking physics . . .