LHC at 50/μb/s

Today the Large Hadron Collider reached a luminosity of 50/μb/s for the first time having fallen just short of that target a few days ago. That means that after 6 months of running at 3.5 TeV per proton they have now reached half of the planned target for 2010. Adding the other half to reach 100/μb/s should be a lot quicker, probably just 2 to 4 weeks. If they can’t do it that quickly they will run out of time for this year.

The latest runs with 152 bunches per beam have not run as long as the controllers would have liked. In each case the beams have been dumped prematurely due to a variety of faults including “UFOs”. These are thought to be flakes of dust from the beam pipe that fall into the way of the beams triggering losses and an automatic dump to protect the systems. This shows just how difficult the process of getting the LHC up to speed can be.

Despite running for only 6 hours the latest run still produced another 1/pb of accumulated luminosity, bringing the total to 10/pb. The next luminosity increase using 200 bunches per beam should start this week.

Update (4 oct 2010): The first run with 200 bunches per beam is now underway with intial luminosity of 68/μb/s which is 2.1/fb/year

Update (5 oct 2010): The run is still going after 12 hours with 2/pb delivered.


5 Responses to LHC at 50/μb/s

  1. Luboš Motl says:

    10/pb is already interesting for some new not-quite-insanely contrived physics. I wonder how many people are actually evaluating the available data now.

    I guess that 50/microbarn/sec is 1.577/fb/year, right? So another factor of three or so would be helpful…

  2. Philip Gibbs says:

    Another factor of three would give them a chance if they can run efficiently. They actually only have about 9 months of running next year. If we assume they run at 2/3 of peak on average during a fill, and for 2/3 of the time, that means they need 3/fb/year, so another factor of two. But the question is how much time will be lost due to outages and prematurely dumped fills. They may be down half the time so a factor of 4 to 6 would make it more comfortable.

  3. Bill K says:

    Maybe the UFOs are traces of the soot that was generated by the 2008 explosion. It would be interesting to see how UFO incidents are distributed around the ring, or if they are occurring mainly in one beam.

  4. Lawrence B. Crowell says:

    Is there any news on the observation of heavy ion-like behavior at this higher luminosity?

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