LHC cooled down for 2011 run

The Large Hadron Collider’s cryogenic systems have now cooled down all the superconducting magnets to 1.9 degree Kelvin as required for this year’s physics runs. This means that the main accelerator ring is essentially ready for beam injection which is scheduled to start on 21st February.

The plan will be to bring the collider back to last years peak luminosity of 0.2/nb/s as quicky as possible so that the experiments can start to add significant data to what they have already collected. The bunch spacing used will be 75 ns instead of the 150 ns used before. With this closer packing it should be possible to circulate about 900 bunches in each beam to more than double the beam intensity. Further luminosity increases will be achieved with a tighter squeeze of the beams at the collision points. Overall they hope to slowly progress towards 1.0/nb/s luminosity then just work on maximum running efficiency.

Some problems identified towards the end of last year will have to be dealt with. This includes Unidentified Falling Objects in the beam pipe and a build up of electron clouds. To clean the pipes they will “scrub” with extra high intensity beams at lower energy using 50ns spacing to pack in even more bunches.

As last year, the proton physics operations will end in November to allow time for some more heavy ion collisions. This year they will aim for a significant increase in luminosity for these collisions. At the end of the extended proton physics run in 2012 they may try out collisions of protons on heavy ions.

As last year we plan to closely follow the progress on viXra Log.



9 Responses to LHC cooled down for 2011 run

  1. Bill K says:

    The UFOs are simply dark matter particles.

  2. Luboš Motl says:

    Thanks for the update – whatever was your source of this detailed plan! Just to recall, 0.2/nb/s is 6.3/fb/year. That’s just about 4/fb or so before November.

    The UFOs may be the stopped gluinos who have been hiding in the pipes.

  3. Bill K says:

    The coordination page contains a lot of insider jargon! One almost needs a LHC/English Dictionary. For example, here’s what it currently says for the forthcoming week:

    “Ring closed, BIS lock closed for MKI/LBDS tests”
    “Beam to TI2/8 downstreams TEDs”

    BIS = Beam Interlock System – logic circuit that “ands” all of the beam monitoring components, and gives a final thumbs up
    MKI = Kicker Injection Magnets – they inject the beam from SPS to LHC
    LBDS = Beam Dump System (at point 6)
    TI2/8 = The two transfer lines from SPS to LHC (at points 2 and 8)
    TEDs = Beam stoppers located at the injection points

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