The LHC Dashboard

By JoAnne Hewett | June 20, 2006 1:35 am

The BIG questions on everyone’s mind are: When will the LHC achieve first collisions, what will be the luminosity (event rate), and what will be the center of mass energy of the first collisions? The LHC Machine Advisory committee met last week at CERN and the representatives of the LHC project gave the current up-to-date answers to those questions. The result? Well, we are all a bit disappointed, but not too much so. We understand that prudence and caution is necessary here as this project is a large extrapolation from present machines. All in all the LHC machine folks have done a great job!

Up to last week, the mantra was that the LHC was turning on (first collisions) on 1 July, 2007 with a center of mass energy of 14 TeV and a significantly lower than design luminosity. We were not concerned about the low luminosity – that is typical when commissioning a new accelerator – and the high energy guaranteed that many Tevatron searches would be eclipsed in just a few weeks of runtime, even at the low luminosity.

Now for the reality check, as presented last week by the LHC project manager Lyn Evans (insert drumroll here): The machine will be closed in August 2007 and first collisions will occur in November 2007 at center of mass energy 1.8 TeV. The same energy as the previous run (known as Run I) at the Tevatron! It seems that this decision is very prudent. In 2007, only a couple sectors of the LHC will be fully commissioned to handle 7 TeV proton beams. The remaining sectors will not be commissioned until early 2008.

Let’s think about this for a moment. Commissioning (starting) new colliders is frought with numerous unintentional aborts of the beam. And when a beam is aborted, it has to go somewhere (it’s called dumping the beam). Hopefully it aborts as planned, otherwise….much energy is dumped somewhere it should not be! At full throttle (7 TeV beams), the energy stored in the LHC beam is 700 MegaJoules, or 10 TeraWatts of power while the beam is dumped. How big is that? Well, 10 TeraWatts is about half of the world’s total instantaneous power output. No wonder the accelerator folks are a bit jittery! They don’t want to dump 10 TeraWatts of beam just anywhere…

Here’s a picture (courtesy of Tom LeCompte) to illustrate this point. The kinetic energy of battleship guns is 300 Megajoules, or just less than half that of the full LHC beam. Now we understand why the machine folks want to be a bit cautious…

The detectors, I am sure, are grateful for this reprieve. They have more time themselves to get ready and need not be quite so concerned about getting their hardware fried during the first collisions. It also provides a neat check in calibrating the detector’s performance given the large amount of literature on hadron collider physics at 1.8 TeV energies. The LHC detectors will be able to amass a good sample of W and Z bosons with which to start their calibration.

The plan is for full commissioning for 7 TeV beams to be completed during the winter 2008 shutdown, with the first physics run at 14 TeV center of mass energy to commence on 1 April 2008. And that’s no joke.

For those interested in the nitty-gritty details, here is the schedule of the magnet installation:

Last beam magnet delivered: October 2006
Last beam magnet tested: December 2006
Last beam magnet installed: March 2007
Machine closed: August 2007
First collisions: November 2007

The full progress of the LHC can be monitored at the LHC Dashboard, which displays the up-to-date status of the delivery and installation of every single machine component. It is great fun to watch! Here is a sample case showing the progress of the dipole cold masses:

We see that they are almost, but not quite, on schedule.

This delay may be frustrating to some, but given how long we have waited for this already it is only a small price to pay (and not at all unusual in commissioning new accelerators). The LHC machine physicists are to be commended in their excellent progress towards bringing this great machine online! The whole world is watching and we can’t wait (but we also don’t want the machine to blow up)!

CATEGORIZED UNDER: Science
  • http://arivero.ciberpunk.net Alejandro Rivero

    Ok this is a nontechnical blog entry, but if we are speaking Joules and Watts it could make sense to put some calculation in, in order to substantiate the equivalences. Nor to speak of TeVs.

  • Science

    They are making it sound way too dangerous. Although the power is high (because the duration is small), the actual energy of 300 MJ is not that big a risk. The chunky cast equipment they is probably as tough as those ship’s guns. OK, some magnets and sensors can burn out, but nobody can get hurt (the control station is well shielded).

    There’s more danger in the controlled high temperature nuclear fusion research programs: continuously containing a plasma at the temperature of the sun’s core and enormous pressure, using powerful electromagnets. Any failure in the magnets (which can develop instabilities – as shown by experience with accelerators) and they will face a nuclear fusion explosion on a very short timescale. This would cause neutron-induced fallout activity, from the fusion.

    Sometimes it pays to take changes. I hope CERN gets the LHC going quickly. Physics needs the data fast. They have big budgets and can affort to gamble and take risks.

  • Science

    errata: “…equipment they have is…”
    “Sometimes it pays to take chances. …”
    sorry

  • http://arivero.ciberpunk.net Alejandro Rivero

    How many megajoules is a two liter bottle of Coke, for instance?

  • fh

    So we still have two years to get our phenomenology up to speed, before we’re confronted with data, good! *g*

  • anonymous

    what is the reason for this surprising change in the program? The fact that one has to be careful with LHC beams is not new.

  • http://eskesthai.blogspot.com/2005/10/tall-tales-and-sailing-ships.html Plato

    I am sorry but the very idea fraught with the possible perils of mankind has been re-ignited already?

    Powers of Ten


    Many physical quantities span vast ranges of magnitude. Figures 0.1 and 0.2 use images to indicate the range of lengths and times that are of importance in physics.

    Okay. So, am I loosing perspective here?

    Rest assured, our adventures have been beyond the horizons edge, where it was once thought that falling off would have been the end of it? But whence the “Tall Tales and Sailing Ships(on name),” the Greeks, holding to the “waters edge” were feeling safe at home. Feeling safe on soid ground?

    Once again, we face the modern advances in research, has somehow “awaken the fear” of a sleeping giant(energy)?

  • http://michaeldunn.blogspot.com Michael D

    i’m a bit confused as to what the value of ‘energy’ stored in the beam refers to?

    as you said, 10 Terawatts is half the world’s energy output, so how’s it being generated?

    i know CERN draws a lot of energy from france and switzerland, but how much exactly?
    do they have their own power stations?

    any figures on their greenhouse gas emissions?

    m

  • Markk

    “I’m a bit confused as to what the value of ‘energy’ stored in the beam refers to?”

    Well a Joule is a Watt-second so the key number is the 700 MegaJoules which is
    700,000 Kilowatt seconds, which is about 194 KW-hours. This is roughly the equivalent of 2000 100 Watt lightbulbs running for an hour. Now the total efficiency is probably pretty dang low since they are chilling helium, losing radiation, etc. so I don’t know the power input.

    These are interesting numbers, we can calculate stuff with them.
    Since there is 10 TeraWatts in the beam we see that the beam length is pretty short in duration.

    10 TeraWatts = 700 MegaJoules / X seconds means
    X is about 0.1 millisecond. This seems long to me – means the length of the beam is maybe 20 Km? Relativity may play in here… but that is very roughly the length of the accelerator.

  • LHC by the Dashboard Light

    The idea is that the LHC beams, which when they each contain 7 TeV proton bunches, have a total enery of 700MJ. If the beams are lost, this usually happens in a fraction of a second, dumping 10 Terawatts of power which for that TINY time interval is comparable to that being used by the entire earth. BTW it is the Battleship New Jersy in the picture, which my father helped to build, so I know it is their mounted 16in guns(ie, cannons) that produce the 300MJ..not their machine guns.

  • Thomas Dent

    When did units get this bizarre new CapitalizAtion? Is it because some unit signs have capitals too? … or because TeraWatts look bigger? JoAnne?

    http://physics.nist.gov/cuu/Units/units.html

    apparently only degrees Celsius have a capital letter.

    It would be entertaining to go on and discuss kiloWatthours, milliWatts, millielectronVolts, nanoKelvin …

    As for what LHC should be doing, clearly no unnecessary risks should be taken. The science programme should run over many years and it makes no sense to try and push it a couple of months earlier by neglecting precautions. My supervisor told me the story of SLAC being turned on, where they had trouble finding the beam because unlike LEP there were not enough beam sensors built in. Not a disaster, but certainly a big setback.

    T

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  • http://blogs.discovermagazine.com/cosmicvariance/sean/ Sean

    This sounds like good news to me, just because it indicates that they are being realistic about what is going on (or at least, I hope it does). Nobody ever really believed they would start on time, did they? When I visited CERN last summer and asked someone working on ATLAS if they’d be ready on time, they said “Sure we will… but if the beam is a little delayed, we won’t exactly be complaining.”

    The particles will still be there.

  • Barry

    Do you realized that you just killed at least 100 retired naval gunnery chiefs with that comment about ‘machine guns’? They’re *cannons*.

    -From an ex-grunt who still knows better.

  • http://blogs.discovermagazine.com/cosmicvariance/joanne/ JoAnne

    To all who are concerned about the loss of human life when the beam is aborted. Don’t worry! The accelerator and collision halls are deep underground and well shielded. Numerous safety precautions will be in place and people will not be allowed to access any dangerous area when the beam is turned on.

    However, uncontrolled beam loss could lead to serious damage to the accelerator itself, and even worse, could literally destroy a detector. Damage to the accelerator could be repaired given sufficient time and money. The big experiments cost about $1 Billion each and took about a decade to build, and if one were to receive significant damage it might be impossible to replace. This is very sensitive equipement, certainly not made of cast-iron as are battleship canons/pistols/machine guns/rifles/or whatever they are called.

  • units

    The energy is 700 MJ. The LHC circumference = 26.7 km (= LEP). The speed is c = 3e8 m/s. The circulation time is T = L/v = 8.9e-5 sec. The power is P = E/T = 700e6 / 8.9e-5 = 7.9e12 = 7.9 TW. It will not cause the end of the world. Don’t panic.

  • http://pantheon.yale.edu/~eal48 Eugene

    All this talk about particle beams going haywire and blowing things up remind me of this awesome video game that I played when I was a kid.

    http://en.wikipedia.org/wiki/Another_World_(video_game)

    “The protagonist of the game is Lester Knight Chaykin; a young, brilliant, athletic, red haired physicist. Chaykin is transported to a barren alien planet after lightning strikes his particle accelerator during a unique experiment in his high-tech underground laboratory.”

    The initial scene of the game, Lester drove his ferrari recklessly into the parklot of the particle accelerator building is one of the best intro scene I’ve seen in a game or a movie. Video games are always much more hip in protraying physicists as all-action heroes.

  • Q

    I expected Cynthia with her love for Joules to make some comment or contribution on this one.

    JoAnne the “blast” from the big guns on two battleships? All in a days work (target practice) for the US Navy.

    And the worst that could happen a spectacular 1billion US$dollar or is it “euros” backfire … small peanuts, or is it small potatoes, – gone in a watt? 0.1millisecs?

    Alejandro how many MegaJoules in a litre of Coke? and how many did you say in a pound of sugar or a pack of biscuits?. This must be one of JoAnne’s gotta laugh days

  • Michael

    JoAnne, could you please learn the difference between power and energy?
    Thanks,
    Michael

  • Nick

    Power is the rate of energy per time. As in how speed is the rate of distance per time.

  • Cynthia

    Q… Excellent Recall! I still proclaim that the world’s leading currency is not the “Dollar” but is the “Joule.”

  • http://www.valdostamuseum.org/hamsmith/ Tony Smith

    JoAnne said, about LHC, “… The plan is for full commissioning for 7 TeV beams to be completed during the winter 2008 shutdown, with the first physics run at 14 TeV center of mass energy to commence on 1 April 2008. And that’s no joke. …”.

    Peter Woit asked (in a comment on his blog pingbacking this blog entry):
    “… Anyone want to guess how long it will be from April 2008 until the experiments have enough data to say something interesting, understand their backgrounds, and are ready to go public with results of the data analysis? How long did it take in the case of the Tevatron? …”.

    In the case of the Tevatron with respect to discovery of the T-quark, here are some quotes from the book “The Evidence for the Top Quark” by Kent W. Staley (Cambridge 2004), with my comments [in brackets]:

    “… As of February 1987,CDF expected to begin their … run in November of the same year …

    … the lab … revised the schedule … begin antiproton transfers to the Tevatron on June 6 1988 … [schedule revision similar to LHC now]

    Throughout the 1988-89 run, CDF was in a kind of race with … UA2 … at CERN … CDF won this “race” early in 1989, not by finding the top, but by showing … a top mass limit that ruled out its discovery by UA2 … [ similar to LHC winning the Higgs race when its mass appeared to be at beyond the reach of Fermilab]

    around … 1991 … Kondo analyzed … the first … published … CDF dilepton event … from the 1988-89 data … Kondo found that the event could be reconstructed as the decay of a top-antitop pair, with a top mass of around 130 GeV/c^2, but “it has a very broad error” … Kondo … wanted to publish …[a]… paper in PRL … The paper met resistance from the collaboration, who felt it too closely resembled a top discovery claim … Kondo “didn’t make … trouble”, and instead published the paper in the Journal of the Physical Society of Japan …

    In 1991 … Goldstein and Dalitz … were trying to apply their method [of data analysis] to the first CDF dilepton event …[so they]… asked … Sliwa … for … help …

    Goldstein and Sliwa … presented results at a heavy flavors group meeting in April [1992] … showing a bump in the probability distribution at a top-quark mass of about 120 GeV/c^2 … After that, according to Sliwa, “Goldstein was told not to come to Top Group meetings,” a decision that Sliwa believed was “highly improper” …

    the July 24 [1992] issue of Science … described the position of Dalitz and Goldstein … “They think the patterns they found look suspiciously, though not unambiguously, like the top quark and deserve further analysis.” CDF, the article noted, “isn’t impressed” … The Science article described Dalitz and Goldstein as having “gained access to unpublished, partially analyzed CDF data only when Krys Sliwa, a member of the group, shared it without telling his colleagues.” … Goldstein denied both the sense of furtiveness and and secrecy conveyed by the Science article…

    In June of 1992 … the run designated “Ia” began …

    On October 29, 1992, just prior to the meeting of the … DPF … CDF recorded an event that looked strikingly like an e – mu top decay … In fact, although it was not known at the time, one of the jets in this event would be tagged by both the SVX and SLT b-tagging algorithms … some collaboration members even regarded the event by itself as worthy of publication as a top-quark event … the event, … known as “the DPF event”, would be shown at the meeting … No claim would be made what the event signified …

    On April 26, 1994, … CDF … release[d] … a paper describing “evidence for top quark production” … D-zero did not claim to have established such evidence …”.

    Some questions that come to mind:

    1 – How will LHC deal with release of individual event data, to avoid controversies and yet permit outsiders to contribute their methods and interpretations,
    in the light of the fact that the Kondo and Dalitz/Goldstein/Sliwa methods of analysis were (and still are) useful techniques developed outside the collaboration ?

    2 – How will LHC deal with release of its internal analyses, bearing in mind that the DPF event was released in 1992 and it was not until 1994 that a discovery “evidence” paper was released ?

    Tony Smith
    http://www.valdostamuseum.org/hamsmith/

  • http://blogs.discovermagazine.com/cosmicvariance/joanne/ JoAnne

    So I forgot to give the elasped time when converting from energy to power and I used a funny capitalization. Sue me!

    The physical definition of power is the rate at which work is done, P = dE/dt. In units, 1 Watt = 1 Joule/second. The 10 TeraWatt figure is the power dispensed by the beam in the fraction of a second it takes to be aborted. Given the numbers above, that fraction of a second works out to be roughly 10^-4.

  • http://blogs.discovermagazine.com/cosmicvariance/sean/ Sean

    Oh, but JoAnne, they will sue you. Under the Blogger’s Responsibilities Omnibus Reconciliation Act of 2005, the existence of a trivial mistake in a blog post entitles readers to demand compensation to the tune of one thousand times the fee they are paying to read this lovingly-constructed blog.

    So be careful, willya?

  • http://quasar9.blogspot.com/ quasar9

    JoAnne said: “Sue me!”
    Now I definitely know it’s a JoAnne gotta laugh day. lol! – Q

  • jls

    JoAnne, thanks a lot for the update and the pointer to the LHC dashboard. I really appreciate the information and the time you spent to keep everyone posted.

  • garbage

    “The energy stored in the LHC beam is 700 MegaJoules, or 10 TeraWatts. How big is that? Well, 10 TeraWatts is about half of the world’s total energy output.”

    I’m confused with the choice of units. Furthermore, are u gonna tell me that the LHC stores half the total energy output of the world!!….per century? :)

  • JoAnne

    jls: thanks. You have obviously learned that flattery will get you very far in this world! I think all commenters should do nothing but praise my brilliant prose.

    Garbage: Please read my comment #24.

    Tony Smith: The subject of how/when the LHC folks are going to release their data is literally going to be the subject of my next post. So stayed tuned….

  • http://countiblis.blogspot.com Count Iblis

    10^(13)Watt = 4.1 x 10^(-2) GeV^2 :)

  • http://arivero.ciberpunk.net Alejandro Rivero

    #19, Q, well, the nutritional needs of an adult human are about 2kwh, so well inside the megajoule range.

  • http://arivero.ciberpunk.net Alejandro Rivero

    (the daily nutritional needs, I mean)

  • http://www.math.columbia.edu/~woit/wordpress Peter Woit

    JoAnne,

    Your prose is brilliant.

    Tommaso Dorigo says he predicts nothing coming out before summer 2009. When data does come out, do you think the theorists who have been participating in the “LHC Olympics” will be able to put what they have learned to use?

  • http://blogs.discovermagazine.com/cosmicvariance/joanne/ JoAnne

    Peter,

    As a fellow blogger I see you understand that the likelihood of getting your question anwered is directly correlated to the niceness of your comment!

    Seriously, I saw this on your blog yesterday and meant to respond but got distracted. I am glad you brought it up again.

    So, regarding when announcements of discoveries will come out of the LHC – it depends, naturally, on what is being discovered. If there really are blackholes at a TeV, or if there is a heavy gauge boson (or Randall-Sundrum type graviton Kaluza-Klein resonances) at 2-3 TeV, then we will know very quickly. Probably during the 2008 physics run. However, missing energy signatures (such as for Supersymmetry) or the Higgs to gamma gamma channel will take a few YEARS. Those signatures require exact calibration and knowledge of the detector.

    Now, you asked about the LHC Olympics. Up to this point, this excerise has been largely ignored by the phenomenological community, because quite frankly we find it rather useless. This excerise is precisely what our research has been about for the last 20 years and we feel that we don’t need to bone up on the basics. However, part of the more formal particle and string community have been working on it. I am not aware of any great progress, but then, I admit that I have not been paying much attention.

    Joe Lykken, in his summary talk at the yearly phenomenology meeting, Pheno06, presented a quiz to the phenomenology community. He presented two examples of possible “discoveries at the LHC,” the first was simply top-quark production and the second was a combination of the production of a couple of new particles. Joe simply showed some kinematical distributions, just as any experimenter would do during a talk, and asked the audience to guess what the signal was. The result – well, we nailed the top-quark production signal instantaneously, and after a couple of minutes got the double new particle production too.

    My point, I guess, is that the LHC Olympics folks have alot of catching up to do. I think it is good that they realize this and are interested and are working on it.

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