LHC could provide up to 14/fb in 2011

Today there is a status meeting for the Large Hadron Collider that can be viewed as a webcast with slides also online. First to talk was Steve Myers reporting on the latest progress with beam commissioning. As we reported yesterday evening they have already surpassed last years luminosity limits with a run that collected 6/pb in 8 hours. This year they expect to have 124 days of full proton physics so even the most pessimistic forecasts where they collect 6/pb twice a day using present luminosity they would collect 12×124 = 1488/pb = 1.5/fb , easily passing the 1/fb goal for 2011.

So what is the upper limit they might reach? Myers is too cautious to suggest an answer but he has given us some more details that helps us to answer this question. In the next few weeks they will do scrubbing runs to clean out the beams and reduce the electron clouds that are adding to the unwanted background in the experiments. Depending on how successful this is, they will make a decision to run with either 50ns or 75ns bunch spacing for the rest of the year. With 75ns they can get 936 proton bunches in each beam, but 50ns would allow for 1404 bunches. Before the 124 days of full intensity running begins they have allowed for 40 days to ramp up the bunch numbers to these levels, so optimistically we can count about 140 days of full intensity runs. They could already collect about 15/pb in a day with 200 bunches so with 1404 bunches  they could collect about 100/pb per day. This sets an upper limit of  about 14/fb for the year or 9/fb if they opt for 75ns spacing.

Just to be clear, I am not predicting that 14/fb will be collected, I am predicting that less will be collected. This is only if everything runs as smoothly as possible. A better prediction will be possible in a few weeks. To ensure the best possible outcome Myers asks everybody to do this…

7 Responses to LHC could provide up to 14/fb in 2011

  1. Compyblog says:


    Ich hab schon eine Weile nichts mehr vom LHC vermeldet, aber heute gibt es doch wieder einen Grund für eine Meldung. Wie es aussieht funktioniert der Beschleuniger insgesamt so gut, dass die mögliche erreichbare Datenmenge für das Jahr hochrechnungswei…

  2. Bill K says:

    Caption: “I believe in supersymmetry. I believe in supersymmetry…”

  3. Urs says:

    12*124=1488/pb = 1.488/fb, somewhat smaller than your title suggests

  4. katzeee says:

    @urs: don’t stop reading after the first paragraph

  5. [...] optimista, pero no tanto como Philip Gibbs, “LHC could provide up to 14/fb in 2011,” viXra log, March 23, 2011, que ha leído entre líneas en esta charla que en 2011 se [...]

  6. Luboš Motl says:

    Hi! The LHC is now trying 50 ns! It has

    AFS: 50ns_1236b_72bpi_18inj_scrub

    1236 bunches almost sounds like your dream numbers. ;-)

    • Philip Gibbs says:

      But they are not going to ramp up to 3.5 TeV. These are the scrubbing runs to clean out the pipes.


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