Slashdot Mirror
CERN LHC Reaches Its Goals For 2010
Anonymous Dupaeur writes "The goals for the first run of the most powerful particle collider (and the most energetic storage ring since ISR) were recently surpassing the 10^32 level of luminosity, with a destructive 15 MJ energy per-beam. This is a significant milestone, opening the way to collect more and more data. The current plan is to stop the proton collisions soon, and provide an ion (Pb) beam and conclude this year with a X-mass break. The next year is expected to bring at least one inverse femtobarn of data, which is achievable with such beam power. After that, the entire accelerator complex will be shut down for a year, due to budget costs for science in Europe."
conclude this year with a X-mass break.
Is that supposed to be some kind of punny joke?
Summary is incorrect. The LHC is NOT shutting down due to budget cuts. It was planned to shut down to accommodate the upgrade to full 7TeV beams. The budget cuts are responsible for shutting down other accelerators (not LHC). If you can even name one of these other minor accelerators, you know more about CERN than I do (and IAAPP).
Well, if a femtobarn is a really really small barn, then its inverse would be a really really small anti-barn.
When two such particles collide, you'd better get the flock out. At least that's the little I've herd.
There you go again, always complaining about black holes. You can bet that if they produced a whole gang of planet-destroying white holes it wouldn't even make the back page of the crime section.
This is my favorite bit:
10^-40 meters square = picobarn
10^-43 meters square = femtobarn
10^-46 meters square = attobarn
10^-52 meters square = shed
.
You take the number of inverse femtobarns ( units of 1/area ) times the cross-section of the interaction/particle/whatever that you're looking for (which varies with energy) to get the total number events that you should see. So, inverse femtobarn is a good unit for amount-of-data-collected.
Have they used the Large Hardon Collider to make a black hole yet?
There has never been more of a need for the -1 obvious flag.
It's not really a measurement of collision events, though it is proportional to it. Think about it classically, for a beam of billiard balls, say. The number of collisions you get will be proportional to to the area of beam, the number of particles per unit area for beam 1, the same for beam 2 and the cross-sectional area of the balls. All the factors apart from the last are shoved together in the luminosity figure - which has dimensions of inverse area and the barn is a unit of area.
So the integrated luminosity (in inv. barns) * the cross-section of the process you're interested in (in barns) gives you a number.
In reality, the cross-sections don't correspond directly to physical areas (it's all quantum after all) but the principle is the same.
Wow. Your analogy didn't make anything clearer. I'm just as confused now as I was prior to reading your comment. Perhaps more so!
*sniff*
I'm so proud
The cost is too high to run next year. That is disappointing.
Bad reporting. The LHC has scheduled maintenance in 2012.
However, CERN has more accelerators than just the LHC, and those will
be shut down due to financial constraints. They don't do much cutting edge
research anyway, so the science output is largely unaffected.
Shutting down the LHC for other than technical reasons isn't planned at all.