This week, the luminosity of the LHC exceed 1 x 1032 cm-2s-1 for the first time. Remember, luminosity is a measure of the rate at which the protons are colliding, and it depends on things such as the number of particles circulating in the machine and how well the beams are focused; the greater the focus, the denser the particles are within the beams and thus a greater chance that they will actually collide.
In the past month and a half, we have seen a significant increase in the luminosity. Now, the physicists on the experiment actually care about the integrated luminosity, i.e. the total number of collisions that have taken place, because that sets the size of our data sample. But of course if you want to integrate luminosity, you want to have a high instantaneous luminosity, and that is what the LHC is giving us. In particular, CERN management has said all along that the only possible way that the LHC will meet its integrated luminosity goals for 2011 is for the machine to reach at least 1E32 during 2010. And now we’ve done it! Congratulations to the LHC team. We’ll still need a factor of two, at least, next year to be able to meet that goal, and a lot of that will come with simply filling the LHC with more and more protons. But that is next year. Right now, we’re focusing on this year, and there’s not much left of it for proton-proton collisions! In November (just two weeks away!), the LHC will switch over to colliding lead ions, and the nuclear physicists amongst us will be running the show.
How strong will we finish out October? Ask us in two weeks, of course!
