Posts tagged LHC

Well, the holiday season in Geneva is certainly getting off to a festive and boisterous start.  From the pretty lighted trees by the lake to the yet-to-be-seen-illuminated Christmas lights in St-Genis-Pouilly, it’s clear that it’s time to get our “fête” on.  Even more notable, the LHC has given us physicists an early present or two.

Needless to say, the past 10 days or so have been quite titillating at the lab.  Thousands of e-mails have been exchanged, hundreds of plots have been generated, and many million cups of coffee have been consumed.  As we “ramp up” for the next few weeks of beam and commissioning before CERN becomes a ghost town, I feel like it’s important to share with you, our devoted audience, a little taste of the magic.

Of course, it’s impossible to stay in the control room for one’s experiment 24/24 (or, for you ‘merkins, 24/7).  So, the friendly guys down at the CERN Control Centre (CCC), the control room for the LHC, have created a web-based resource which one can use to receive up-to-the-minute updates on the status of the LHC proton beams.  My friends, I present to you OP Vistars — Page 1:

Christmas lights for your browser.

If you’d like to check in every once in a while yourself, click here.

This page is a nice way to be kept in the loop about current activities along the LHC as well as its four experiments.  Pay special attention to the ‘Comments’ box in the bottom left.  This usually gives a good description of the plan for the immediate future.  On the top, one can get some crucial beam information, including the number of protons per bunch in an LHC beam (denoted with an ‘I,’ shown for both beam 1 and beam 2), whether or not there is beam circulating (the two big green BEAM indicators), and the beam energy.  The beam which was circulating for the example image was characterized by a proton energy of 450 GeV, which is equivalent to their energy at injection.  Injection is quite a tricky process, and it occurs at points 2 and 8 along the LHC (hence the TI2 and TI8 acronyms).

When you really start to think about it, though, this is a masterfully designed, albeit mysterious, piece of internet.  Actually, many of the individuals who gaze at this site for many hours a day are perplexed by some of its most prominent features.  But the colors sure are nice!  As an example of our confusion, in a survey of some 20 ATLAS physicists (my colleagues), I found that exactly 0 of them knew what the shit was going on in the four plots found in the middle of the screen.  Noting the x- and y-axis labels, one might suspect that these should be showing the beam position in the x-y plane (and the left-most plot supports this), but nothing about plots (b)-(d) suggests this at all.

The ATLAS run coordinator is reputed to have said that, when one of these plots is shaped like the second plot above, the LHC is operating as a fixed-target collider interacting with someone’s head.  I highly doubt it, Christophe.

Perhaps the most elusive question, however, is the following one: Does anyone know what the fuck “OP Vistars” means?