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Three years of delay for LHC startup! April 1, 2007

Posted by dorigo in news, physics, politics, science.

I would never have wanted to post such dreadful news this morning… The  structural problem  found with the magnet enclosures of the Large Hadron Collider is going to have a horrible effect on the start-up schedule of the machine.  

A stress test of the structures performed a few days ago demonstrated that they are quite vulnerable to quenching conditions of the magnets, as explained in this press release by Fermilab .

It now appears that a completely new design of these components of the beam is necessary. Details are still sketchy in the CERN press release, but the most optimistic estimates have been placed at three years for redesign, production, and installation.

This is very bad news for science… I wonder how fresh new graduate students working in CMS and Atlas will feel today, knowing that their PhD will probably end without any collider data to base a thesis on.

UPDATE: ok – this post got far too much exposure and I think it is beyond its original scope to leave it uncommented. It is an APRIL’s FOOL. Sorry to those of you who got hurt by not understanding that in the first place… I made it a bit too credible, and for that I apologize (I find it pointless if an April’s fool is too easy to recognize).

Please understand that there are no official news on any delay in the LHC schedule or in the CMS and Atlas experiments. I simply do not know, until CERN releases some statement. It is possible that the schedule will suffer some delay, but that is only my personal guess. 

UPDATE 2: this post continues to draw too much attention…. Which is fine, but it starts to bother me that people continue to click on the CERN link. Please understand that the CERN link does not work because its not working is part of the prank!!!



1. Tripitaka - April 1, 2007

oh no!!! That is such a cruel blow to all those involved, and frustrating for the rest of us, damn, damn

2. jeff - April 1, 2007

Yes, what terrible news.

3. cowgonemad - April 1, 2007

Darn, I told my girlfriend the story with 5 years.

4. D - April 1, 2007

The cern link doesn’t seem to work…

5. NotConvinced - April 1, 2007

April Fools, anyone?

6. D - April 1, 2007

I am a moron

7. Fred - April 1, 2007

From the above Fermilab press release:

“A full investigation of the failure is underway, but preliminary indications are that structures supporting the inner “cold mass” of one of the three magnets within its enclosing cryostat broke at a pressure of 20 atmospheres, in response to asymmetric forces applied during the test. Such forces are expected on occasion during normal operation of the LHC. The failure does not concern the magnets or the cold masses themselves, but rather their assembly in the cryostat.”

Is this something that could have been predicted or prevented? How much pressure should this component have been able to withstand? Maybe this incident just comes with the territory and we’ll be better off from what we will eventually learn. It also reinforces a greater need for funding to compensate for such unexpected occurances. I still don’t understand why we don’t have at least 3 of these collider beasts, Lord knows we can fork it out when it comes to constructing other priorities.

8. jeff - April 1, 2007

Is this an april fool? I am on shift and aren’t very lucid or in the mood. If it is, well I fell for it.

9. Aymar resigns - April 1, 2007

[…] the start of the LHC will be delayed by several years. Following these reports, the CERN Council had a special meeting today, during which Director General Robert Aymar resigned from his post. I assume full responsibility for what has happened, he said […]

10. Tony Smith - April 1, 2007

Tommaso, the prospect of a delay from 2008 to 2011 (3 years) for LHC startup is bad enough,
what is even more worrying to me is that the cost of “… redesign, production, and installation …[of]… a completely new design of … the magnet enclosures of the Large Hadron Collider …” is not stated,
which indicates to me that it will be very expensive in money as well as time,
maybe so expensive that the relevant politicians might not fund it.

According to a bulletin.cern.ch web page:
“… Some 1232 main dipole and 392 main quadrupole magnets have been manufactured …”.

A paper by Robert B. Palmer and J. Scott Berg in the Proceedings of EPAC 2004, Lucerne, Switzerland, mentions a cost for LHC magnets of about $700,000 each, but I am not sure whether that is for dipoles or quadrupoles.

Assuming that the main quadrupole magnets must be redesigned, produced, and installed, and that each main quadrupole magnet costs $700,000, that would be a $274 million cost increase.

I realize that is a very rough back-of-the-envelope estimate, and may be very far (either high or low) from the actual money cost, but it is a starting point for discussion,
and I feel strongly that discussion of cost is necessary even if it is unpleasant.

Recall the funding problems back in 2001.
A December 2001 Physics Today article (Volume 54, Number 12) by Toni Feder said in part:
“… Managers at CERN … revealed in September [2001] that costs have crept 850 million Swiss francs (roughly $514 million) above the allotted 2.6 billion Swiss francs …
The size and suddenness of the price hike came as a shock, say CERN scientists and council members, who represent the lab’s 20 member states. …
The LHC tab swelled in part due to the added costs of the superconducting dipole magnets — CERN spent 150 million Swiss francs on unplanned prototypes, and magnet assembly climbed some 180 million Swiss francs higher than expected. (Sources close to the issue say the magnet makers inflated the prices.) …
With a combination of loans, austerity measures, and more money from member states, says Maiani, “we should be able to cope.” …”.

It is easy to be critical of the failure to consider asymmetric loads in design, production, and testing,
it is a fact of life that humans are prone to make such mistakes (for example, consider the collapse of the Tacoma Narrows Bridge, and similar oversights continuing even to the London Milleneum Bridge).

If the LHC were to be killed, that might be the end of serious particle physics, since without LHC-type data there is no way to rule out wrong physics models and support improved physics models,
so that
theoretical physics might become just another branch of religion, with belief/faith in supersymmetry or whatever being the only criterion for success in jobs, funding, etc.

I hope that the relevant politicians will be far-sighted enough to fund the redesigned quadrupole magnets by adding new money, and not be forcing cuts in other programs, either present programs or future proposed programs such as the ILC.

Tony Smith

11. jeff - April 1, 2007

Too much time and money was invested and I do not think it is possible that LHC be cut at this time. The real danger is that this be the last generation of physicists willing to invest their lives (biological and career) on accelerator based particle physics. Those that are already involved will sooner of later have their day, but why on earth should a youngster want to harm himself and his family so by entering this type of dead-end? It already was strange for me to see so many talks to high school or college students to encourage them to enter this field. This blow, if it proves to be truely founded, will most proably kill the flow of new students!

12. Malc - April 1, 2007

Well its good news for the Swiss Spaghetti crops. When the LHC gets going the muon flux is going to completely screw them up, especially the younger linguini bushes.

13. Tony Smith - April 1, 2007

Tommaso, I did not realize the April 1 nature of your blog entry until I saw the Resonaances April 1 blog entry saying that Robert Aymar had resigned to be succeeded by John Ellis,
your comment saying
“… 🙂 Mine was far less dramatic and thus more credible… But I enjoyed yours a lot! Particularly the idea of appointing Ellis… Cheers, T. …”.

I admit my gullibility in believing your blog post,
but, since Truth can be stranger than Fiction,
is it possible that your “Three year delay” due to “redesign, production, and installation” might be true, or even an optimistic view ?

The fact that no further statements have been issued by CERN make me wonder about that,
especially since Physics Web has a news article ( NOT dated April 1 ) by Jon Cartwright that says in part:

“… Large Hadron Collider faces delay 30 March

Although CERN has not yet issued a formal statement on the set-back, it looks increasingly unlikely that the LHC will come on-line this year as planned. …
Originally slated for 2005 start-up, the LHC has already suffered several delays. CERN was caught out in 2001 when it emerged that the LHC was to cost 30% more than originally envisaged and was also running behind schedule. The committee that reviewed CERN’s operations in the light of these overruns recommended that the collider’s start date be put back from 2005 to 2007, and the lab will have been anxious to ensure that this date does not slip any further. …”.

Tony Smith

14. dorigo - April 1, 2007

Hi Tony,

indeed, it was an april’s fool, but a quite credible one, because truth might indeed be even worse. I must confess I have no information on the matter other than what you also have read around the blogosphere and in the FNAL site, but I am with you in being worried. I still hope this issue may be resolved with an easy fix of some kind. Even only six months of additional delay would do a lot of damage. Let’s sit an wait…


15. dorigo - April 1, 2007

Hi Jeff,

I agree, those that would most dearly pay for a further delay would be the students. Let’s hope this thing really pulls up from the ground!


16. dorigo - April 1, 2007

Hello Fred,

I know little about the details, but I can only guess that the stress test that failed was one which would have been hard to predict with simulations beforehand. That, in fact, is the whole point of doing tests with the real structures… I am a bit surprised the test was done so late in the game, however.

I hope that is because the failure means nothing bad.


17. Best Of The Day - Asymptotia - April 1, 2007

[…] the quote from the new appointee is funny. See that post here (it riffs on an earlier post located here, which also has some good -if alarming- […]

18. Torbjörn Larsson - April 2, 2007


It seems the triplets are located on each side of the four interaction points, and consists of 4 quadrupoles each. I haven’t got hold of the LHC design plans, but see for example http://lss.fnal.gov/archive/2005/conf/fermilab-conf-05-399-td.pdf . (Btw, I note the report of initial quench and transport damages.)

The total of 32 delivered low-Beta magnets would lower your guesstimate of cost some. But it still looks expensive if there are drastic consequences.

19. April Fooled at the LHC « An American Physics Student in England - April 2, 2007

[…] was marked by several of the usual April Fools jokes on the Internet. The best post I found was by Dr. Tommaso Dorigo, who played off of the actual news of a failed LHC high-pressure magnet test to `leak’ […]

20. Tony Smith - April 2, 2007

Torbjorn Larsson said: “… the triplets are located on each side of the four interaction points, and consist of 4 quadrupoles each … The total of 32 …”.

The Physics Web news article ( NOT dated April 1 ) by Jon Cartwright said, in addition to the excerpt that I quoted in a comment above:
“… The protons will be guided around the ring by some 6000 superconducting magnets of various types. These include 392 “quadrupole” superconducting magnets that are designed to focus the proton beams before they collide at four interaction points around the accelerator. …
scientists at CERN performing preliminary tests on three of these quadrupoles witnessed a serious failure when structures supporting one of the magnets broke at a pressure of 20 atmospheres in response to “asymmetric forces” that were applied during the test. It is essential that the magnets can survive such unwanted pressures, which will occasionally be generated when the LHC is up and running. …”.

Since I don’t know a lot of details of how the LHC is put together, I must rely on information from people like Torbjorn and publications like Physics Web.

So, I personally don’t know for sure whether the number of questionable quadrupoles is 32 or 392, and I hope that some day CERN will issue an official statement in detail.

Whatever is the number, if the quadrupoles are already placed in the collider, would it be difficult (i.e., expensive in time and money) to remove them so that they could be replaced ?

Tony Smith

21. dorigo - April 2, 2007

Hi Tony,

the number of structures affected is, to my understanding, 16 (two pairs for each of four points along the beam where low-beta squeeze happens). 16 or 32 makes little difference, though. What makes a difference is whether an easy fix is found, that is if the problem is found to be virtual (say, if the stresses of the test are above what can happen, or if the stress can be reduced in some other easy way than modifying the magnet support design), or if a real overhaul of the pieces is needed.

Removing the structures should not be a big issue. Replacing them is, since no replacement exists that I am aware of with different characteristics.


22. island - April 2, 2007

I just can’t handle the idea of giving theorists three more years to hype their BS before the hunt starts, so at great sacrifice to myself I’ve decided to donate my rare collection of SUPERMAGNETS to the cause.

Don’t say that I never did anything for the LHC project… 😉

Seriously, this is unbelievably bad news.

23. Torbjörn Larsson - April 3, 2007


Thanks, with the update we have to come clean and note that we *did* see the AF context. 😉 But Tony had a large concern.


That it was the only “triplets” affected was mentioned in Dorigo’s links, which is why I didn’t motivate it closer. The exact number of quadrupoles involved is confusing OTOH.

24. Tony Smith - April 3, 2007

Tommaso and Torbjorn, thanks for clarifying the number of magnet systems involved. I have just now found a CERN lhc-machine-outreach page entitled “Types of Magnets” that says about quadrupoles:

“… Lattice quadrupoles MQ 392 twin

… Quadrupole in the insertions (3.4 m) MQM 46 twin

Quadrupole in the insertions (4.8 m) MQML 36 twin

Wide aperture quadrupole in the insertions,
twin aperture MQY 24 twin

Quadrupole in the insertions (2.4 m) MQMC 12 twin

Twin aperture warm quadrupole in IR3 and IR7.
Asymmetrical FD or DF MQWA 40 twin

Twin aperture warm quadrupole in IR3 and IR7.
Symmetrical FF or DD MQWB 8 twin

Inner triplet quadrupole, single aperture (Q1, Q3)
MQXA 16 single

Inner triplet quadrupole, single aperture (Q2)
MQXB 16 single

… Skew quadrupole (a2) in MQSXA MQSX 8 single …”.

So, as you say, there are lots of quadrupoles,
but as for triplets, there are only 16 MQXA and 16 MQXB.

Have all the other types of magnets been fully tested,
or is it possible that other unpleasant surprises might happen in the future ?

Tony Smith

25. Torbjörn Larsson - April 3, 2007


From memory (too lazy right now) the triplets weren’t tested for the quench stresses when mounted. Presumably, less complex mounts doesn’t have that problem.

26. Tripitaka - April 4, 2007

Island: “I just can’t handle the idea of giving theorists three more years to hype their BS before the hunt starts, so at great sacrifice to myself I’ve decided to donate my rare collection of SUPERMAGNETS to the cause.”

Oh yes I love it!

PS Tommaso you are a troublemaker, certainly had me fooled ha!

27. Quantoken - April 4, 2007

This might just be the tip of the iceberg of the engineering nightmare for the whole LHC project. I said before, building the thing is just a matter of building individual components and put bolts and nuts together, operating this thing successfully, that’s a totally different matter.

The accident exposed structural weakness in dealing with the catastrophic quench events, which WILL occur during normal operation. Quench may be caused by power failure to any part of LHC, or just power unstability, or any of other failure conditions.

Just think about how much energy is stored in the high energy particle beam, in the energy stored in the magnetic field of the super strong supercondutive magnets. All the energy will have to released instantly upon any quench incident. And that is a very destructive energy.

Now think about how much that energy is, it is equivalent to roughly 1000 kilogram of TNT dynamites. Now try to devise a way, to detonate 1000 kilograms of dynamite, within the tunnel of LHC, safely, without causing any damage to any equipment or personel. This is not a design issue. This is not an engineering issue. This is an issue of an obstacle that is virtually impossible to overcome in today’s technology.

Energy equivalent to 1000 kilogram of dynamite. How do you quench that energy safely? You can’t!

Here is the FAQ, scroll dow to the bottom “What Happens If the Beam Becomes Unstable”:


Any magnet that can deflect such high energy beam must necessarily be big and strong and store extremely high energy just in the magnetic field itself. I do not think they have such a deflecting magnet that can be swiftly turned on in just 0.3 ms and instantly deflect the beam. It’s a flat out lie. I do not think it exists.

28. dorigo - April 4, 2007

Hi Quantoken,

0.3 milliseconds seem like a blink, but it is a long time interval in terms of acceleration operations. Remember the principle behind stochastic cooling of a beam ? A sensor “picks up” the divergence of a bunch of protons on one side of the ring, and sends a signal through the diameter to a magnet which is able to give a small kick to the incoming packet…
And you do not need a magnet to turn on from scratch to get the beam down a dump line, but just a small deflection from the ordinary path.

As for the total energy of the magnets: it is indeed enormous, but they are decoupled systems to a large extent: to think they all release their energy at once is like thinking all the rain falls from a thunderstorm cloud in the same instant…. Both things would cause a lot of damage, but it just does not happen.


29. Quantoken - April 5, 2007

Hi, T:

“A small deflection from the ordinary path” is easier said than done. Remember those are extremely high energy particle beams. Even with thousands of super strong magnets you barely make one small deflection at a time that the whole beam barely makes a U turn in 25 miles in diameter. That’s the whole point why the accelerator is built in such a huge circular tunnel. Just do some simple calculation, even if you want to deflect just one degree, how long a distance does the beam have to travel within a 8T magnetic field.

You literally have to have a giant magnet and turn the magnetic field from 0T to 8T instantly to make even that small deflection. That is a huge injection of energy to build the magnetic field up. I don’t know ho you can do it within 0.3ms time?

30. Quantoken - April 5, 2007

And what makes you think individual magnet would not fail at the same time? LHC consumes electricity equivalent to half of Geneva’s consumption. If there is a catastrophic power failure, then all magnets will fail at the same time.

It only takes one magnet falling into an unstable state, and the beam will be ever so slightly deflected from where it should be, and it is just a few milimeter off and would hit the metal part of the next magnet head on, totally destroying the superconductive state of that magnet, and then BOOM all the beam hit the same spot on the metal shell of LHC, like a chain reaction traffic accident on snowy highways. I don’t see how that can be avoided.

31. dorigo - April 5, 2007

Hi Quantoken,

my studies of Accelerator Physics date back to when I was a graduate student – yes we had a 20 hour course on that, and there was an exam at the end! Anyway, that was more than 10 years ago and I admit I am quite rusty on the details.

That said, you ignore the fact that to deflect a beam you can just _decrease_ the field of a bending dipole, rather than turning one on. I have no time to dig the data out for the LHC, and I actually do not think the use of the normal bending dipoles is the way the safety system of that machine work for dumping the beam, but consider that much less than a degree is necessary to deflect the particles: for instance, 10 arcminutes of deflection off a curved path in the LHC ring provide a separation of the beam of more than one inch per 10 meters.

About catastrophic power failures, they are never instantaneous -again, 0.3 milliseconds are a long time. Along 27km of power lines, I am sure there are devices that provide the needed protection against what you envision.

About the beam being lost, that is indeed possible, but it is not as destructive as a global quench of all the LHC magnets… If you really insist I will try to get some more information on how the accelerator is designed to deal with those situations, but again, one quench is not nearly enough to cause the destruction you describe: quenches are normal, to some extent, in a system of that complexity.

If you find the above too vague, I apologize… I tend to try and avoid running for information until my arm gets twisted.


32. Quantoken - April 5, 2007

Thanks for your willingness to discuss the technical issues. But I think 10 arcminute is a big angle to bend. Along the 27 KM circumference there are 1232 main magnetic dipoles, bending the beam a full 360 degrees. So each one main dipole magnet, at full power, barely bend the beam 17.5 arcminute. So to divert the beam for even 10 arcminute, one of the magnet must instantaneously lose 57% of its magnetic field strength, to reduce bending from 17.5 arcminutes to 7.5 arcminute. How could you do it instantaneously?

In general physics you know magnetic fields could not change suddenly. It could only change gradually, changing magnetic field induces electric current.and that’s how transformers work. It means you really can not instantaneously change the bending angle of a magnet from 17.5 arcminutes to 7.5 instantaneously. It will be a gradual transition, depending how fast you can allow the magnetic field energy be safely released. Such gradual change of the bending angle will mean part of the particle beam, actally 100% of them, if the change takes longer time than the round trip time of the beam. This part of the particle beam will hit the metal part of the vacuum enclosure before they could be diverted enough to enter the safety dump path. If the beam touches any metal part, it’s a huge release of energy and a huge explosion, destroying anything. I just don’t see how you can avoid that? It’s as if you are trying to exit a highway, and you are not turning the steeling wheel enough and you hit the midway curb between the highway lanes and the exit lanes. And it is a catastrophy.

Another factor to consider is if one of the magnet is quenched, and it is at least half circumference away from the beam dumping site. So this magnet fails to bend the beam for 17.5 arcminute that it is responsible to bend, to keep the beam safely within the vacuum tube the next magnet must compensate and bend the beam 35 arcminute to make it up. How could the next magnet instantaneously double its magnetic field strength, and instantaneously, if it is already working near its maximum capacity (8T) by design. And very likely, one failed magnet and the beam will be diverted enough to hit the vacuum tube, which is barely an inch or so in diameter, before it even enters the next magnet for corrective action!!! How do you deal with that?

33. Quantoken - April 5, 2007

I am trying to find out exactly how they plan to do the beam dump safely. And here is the page I reached:

Main components of the LHC accelerator:


Notice that everything has a valid URL link, except for the “beam dump” where there is NO url page link at all. Guess they have nothing to say about beam dump?

34. Quantoken - April 5, 2007

Here I find a more detailed description of the beam dump mechanism:


So the key is they have a fast kicker magnet which could quickly switch from zero to norminal magnetic field in just 3 microseconds, and when it’s fully turned on it deflect the beam 280 micro radian angle. The trick is they allow a 3 us “particle free gap” within the beam and the kicker started the 3 us switch right when the particle free gap arrives. The kicker finishes the 3 us switch-on while there is no particle within that 3 us window.

Sounds good but how do you make a fast kicker that switches on that fast? The main magnet is 14.3 meters long with a magnetic field of 8.4 tesla, and bend the beam 5.1 mili radian. For the fask kicker to bend the beam for 280 micro radian, the field strength times the length of the path within the magnetic field then must be 6.6 meter*tesla. That’s quite a big magnet to be turned on within 3 us.

Second problem is 3 us gap corresponds to 900 meters of gap within the beam. The beam is composed of 2808 bunches uniformly distributed on a 27 km circonference so the particle free gap between bunches is only 9 meters or less.

35. dorigo - April 7, 2007

Hi quantoken,

I am writing from the mountains, unarmed. I think you are highlighting critical but plain-to-spot engineering issues, which I am quite sure have been addressed thoroughly during design. What happened to the G-11 support structures is instead a much subtler failure, which has much more potential for creating problems.

I remain interested in the issue, but until I come back to my office I am unable to discuss it meaningfully… I really hope we will get more information on the subject in the meantime.


36. Charles T - April 19, 2007

Dear Tomasso,

Your excellent April Fools joke has now got an honourable mention in Nature (although your blog is not explicitly named).



37. dorigo - April 19, 2007

Hi Charles,

thank you… I will check the article when I am back to office – I do not have a personal subscription to Nature, my University does though.

Thanks again for notifying the piece.


38. Jacks of Science − A Large Hadron Leprechaun Hunt - March 16, 2008

[…] their particle collider up and running. Last April 1st I heard that the project was going to be delayed for 3 years! What can one do?Well, I admit that logic and reason have their place in massive engineering feats, […]

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