LHC Alternative 10 Year Plan

As viXra readers know very well, the current plan for the Large Hadron Collider is to run until the end of 2011, have a Xmas shutdown and then run again during 2012 with possibly higher energy and luminosity. Then there will be a long shutdown to replace the magnet splices and make other upgrades so that it can run at the full 14 TeV energy from mid 2014. After a few more years there will be further long shutdowns with other upgrades leading eventually to the High Luminosity LHC.

When this plan was excepted in July 2010 it looked like this

Since then the plan has evolved a little bit, with the long shutdown becoming a little longer and the later shutdowns being delayed further. The currently accepted plan looks like this (as always you can click on the image see a bigger version)

You will notice that there is now very little time for the run during 2014 so serious physics at 14 TeV cannot be expected until 2015.

Of course we have also learnt that LHC plans do not stay fixed for very long and it is now a poorly kept secret that this plan is also due for some major revisions. The latest provisional plan now looks more like this.

The change in plan starts at the next end of year shutdown when the usual two month is replaced with a longer 4 month period. This provides an opportunity for more upgrades, the nature of which is still obscure. Hopefully this improves the likelihood of the 2012 run being at an intermediate energy, 10TeV would be nice, but it may just be that there will be some essential detector upgrades during this break.

The extra delay means that the 2012 run continues well into 2013 until April. There is just a short two week stop over Xmas 2012. The long shutdown is pushed back even further with no 14TeV physics at all until 2015. The later date and the prospect of some very high lumniosity runs during 2012/2013 means that the detectors will be in need of some major work during the long shutdown while the splices are being replaced. We can now expect some of the major parts of ATLAS and CMS to be replaced with upgraded components, including the central beam pipes.

The delay of nominal energies may be disappointing but the prospect of better luminosity and possibly higher energy during 2012/2013 will certainly make up for it.

7 Responses to LHC Alternative 10 Year Plan

  1. Tony Smith says:

    If the next few weeks produce evidence for a Standard Model Higgs and no supersymmetry or new physics,
    and if by Halloween 2011 the evidence becomes discovery with still no supersymmetry or new physics
    in order to explore the massless physics region above electroweak symmetry breaking
    would it be better to get up to 14 TeV as soon as possible
    so that a larger part of the massless physics region could be explored ?

    If so, then why not go back to the original plan of long shutdown in 2012 so that real 14 TeV physics work could begin in 2013 ?


    • Philip Gibbs says:

      A few inverse femtobarns will nowhere near exhaust the discovery possibilities at 7TeV so if they can increase luminosity next year it will be well worth carrying on. If they can also increase energy to 8TeV, 9TeV or 10TeV then the potential for finding new physics sooner is even better with this plan.

      Discoveries this year may influence the energy they want to risk next year, but not that much. No matter what they find, more luminosity and/or energy as soon as possible will always be what they want.

      Aside from that it would not be technically feasible to bring the shutdown forward again at such a late date. A lot of preparation and planning is needed for the upgrades.

  2. Gary Sneed says:

    Whoa Nellie. As of last Chamonix, the risks of running at 8 TeV rather than 7 were considered prohibitive, due to too many questionable splices. Running at 9 TeV was demonstrably unsafe. Where do we get 10 TeV from?

    Has there been some significant progress in the thermal amplifier department? (This is a technique that uses brief current pulses to deliberately overheat splices and measure the effect on the voltage drop across them.) It would take a few months to measure the whole ring, so the 2011/2012 christmas shutdown was suggested. IOW, there hasn’t been time to actually do any measurements.

    • Philip Gibbs says:

      They plan from Chamonix is to do the thermal amplifier tests over Xmas 2011. If this turns into a four month shutdown they will have even more time to do them. 10TeV is the upper limit considered at Chamonix,not likely but not ruled out for 2012.

      The full plans are not public or known to me so I was speaking hypothetically. These are not predictions, just possibilities.

  3. Tony Smith says:

    Based on Gary Sneed’s remark,
    if the LHC would have already discovered a Standard Model Higgs with the 5/fb to be collected by Halloween 2011
    (according to the chart in a previous entry here that could be done
    for any SM Higgs between 128 and 482 GeV)
    if no evidence were then to have been found for supersymmetry or new physics,
    it seems that the LHC would have reached a significant achievement plateau
    if real (not just hopeful) stability up to 14 TeV can be obtained by taking a long break immediately to fix all the known problems (and also any new ones that appear during the break)

    would it not be in the interest of stability of the machine
    (not to mention getting to 14 TeV years sooner)
    to go ahead and take the long break in 2012 ?


  4. Bill K says:

    Remember there are two major issues outstanding that the Long Shutdown must address. The well-known splice repair involves much work but is straightforward. The other is the difficulty with magnet training. The last I heard the root cause was unidentified, and a fix had not been suggested. Repairing the splices alone will only get us to 13 TeV, not 14.

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