BEFORE the days when marketing departments dictated that acronyms should be engineered to sound like real words, a group of Europeans got together in Paris to consider whether their countries should pool their expertise on matters sub-atomic. It was 1953—less than a decade after Robert Oppenheimer, Ernest Lawrence and Enrico Fermi had given America the means to destroy entire cities with a single bomb.

Though the talk then was of the peaceful use of nuclear power—unlimited clean electricity from first fission, and then fusion—the subtext of subatomic physics was military. But for those with more lofty goals, the particle accelerators that had descended from Lawrence's pre-war cyclotrons brought with them the promise of understanding the fabric of the universe at its smallest level. This combination of terror, hope and curiosity meant that physics in the 1950s was sexy in a way that modern physicists can only envy.

The result of the discussions in Paris was the establishment a year later of CERN, le Conseil Européen pour la Recherche Nucléaire (these were also the days before English had displaced French as the lingua franca). Over the decades, CERN has contributed mightily to knowledge of the submicroscopic world as bigger and bigger accelerators have been built there. Now it is re-inventing itself, in an attempt to continue that tradition.

On the surface, CERN is a collection of low, undistinguished buildings on the outskirts of Geneva. But beneath that surface is a secret—a 27km-long, ring-shaped tunnel that juts under France. At the moment, the tunnel is empty. But soon, it will start to fill up with blue tubes whose deviation from straightness is imperceptible to the naked eye. The tubes contain magnets. And when they are linked together in the tunnel they will form a guide path for zillions of protons which will shoot around the ring at close to the speed of light. That guide path will be called the Large Hadron Collider (LHC), and it will be the biggest accelerator of all. If it works—and if theoreticians are correct—it will fill in the remaining blanks of the current model of subatomic physics, and send the first scouting parties into the uncharted territory beyond.

The man in charge of making this happen is Robert Aymar, and his task is not a trivial one. The LHC has already had one near-death experience. In 2001, Luciano Maiani, Dr Aymar's predecessor, announced without warning to CERN's council—a committee that represents the member states—that the machine was 20% over budget. The magnets which accelerate and guide the protons were proving more expensive than expected.

This did not go down well. So in desperation, the council turned to Dr Aymar, who was then in charge of ITER, another big, international physics project (intended to build a working fusion reactor), to report on how the LHC could be brought within budget without increasing members' contributions.

The report was ruthless. It recommended suspending most of the secondary scientific projects at CERN. The money saved plugged the gap. The total bill for the LHC should be about SFr3 billion ($2.35 billion).

The council loved it, and after a discreet interval Dr Aymar took over from Dr Maiani as director-general—only the second non-particle physicist to occupy the post. The robust approach has continued since he formally assumed office on January 1st. CERN's unwieldy management structure has been tidied up. He has compressed the organisation's 13 divisions into seven “departments”. This being an international bureaucracy, it is impossible to force people off the payroll. But natural attrition should cause the workforce to dwindle over the next few years from 2,500 to a planned total of 2,000.

As it happens, this is an ideal time to reorganise CERN. After 50 years, it had become sclerotic. The completion date for the LHC had slipped from 2005 to 2007. And the idea that particle physics has military applications is long gone, so politicians in member states might be forgiven for wondering what they are getting for their money. A shake-up looks purposeful as well as actually being purposeful. It gives the members confidence that their money is not being frittered away—at least, not if uncovering the secrets of nature (and beating the Americans to them) is seen as a legitimate objective.

As to the LHC itself, its first task will be to look for a particle called the Higgs boson. This is something that theoreticians believe should exist if their explanations of why things have mass are true. If the LHC cannot find the Higgs (and the result should be known within a year or so of the accelerator opening for business), then it is back to the drawing board for everybody.

Finding the Higgs boson would complete the so-called Standard Model of particle physics that has come together in the past 30 years. But theoreticians know that the Standard Model itself is an imperfect representation of reality. For one thing, it relies on some 18 arbitrary assumptions being true. The best shot that physical theory has in its locker to replace the Standard Model is called supersymmetry. This would deal with the arbitrary-assumption problem, but at the expense of giving most of the known fundamental particles “supersymmetric” partners that are much more massive, and thus harder to make. The LHC will be able to enter the territory of supersymmetry and discover some of these particles if they actually exist, but would not be able to explore that territory fully. To go further, yet another accelerator will be needed.

In building 18 on the CERN site Ian Wilson plots that future accelerator. Almost all particle physicists agree that the future is a straight line. Circular accelerators have the advantage that particles can be sent round and round them, each circuit adding a bit of energy, and thus speed. Linear (ie, straight-line) accelerators offer only one journey for each burst of particles, so they have to be long.

One reason that they are attractive despite this is that rings waste energy. Forcing a charged particle to travel in a curve generates “synchrotron” radiation, and the faster the particle is travelling, the more energy is lost this way. The losses in a post-LHC ring would probably be unacceptable. But a linear accelerator suffers from no such losses. And yet there remains another problem. The more fundamental the particle being studied, the bigger the machine that is needed. So the linear accelerator required for future experiments is likely to be so big and expensive that most people believe it will never be built using existing technology. Dr Wilson aims to change that technology.

The CLIC (compact linear collider) technology he is developing is one of the few non-LHC projects to survive Dr Aymar's axe. And for good reason. If it works, it could shrink linear accelerators by a factor of four, with no loss of power.

A traditional linear accelerator uses devices called klystrons to give oomph to the particles it is speeding up. These generate pulses of microwaves which carry the particles along as a sea-wave carries a surfer. CLIC technology also uses klystrons, but instead of accelerating a working beam of particles, the klystrons accelerate a “driver” beam that runs alongside the working beam. It is energy from the driver beam that actually pushes the working beam along.

Although this arrangement is harder to engineer, it results in more rapid energy transfer, and thus a shorter accelerator. If converted into an actual machine, that compactness would, in turn, result in huge cost savings, and might be the decisive factor which makes it possible to build a linear accelerator more powerful than the LHC.

Even so, the cost of such a machine would still be so large that only one is likely to be built, and it would be a global project involving America, Japan and anyone else who could be persuaded to contribute. Dr Aymar is bullish about CLIC technology being the right one for the future, but he claims indifference as to where a global linear accelerator should actually be sited. Of course, he is unlikely still to be director-general when the decisions are made, let alone when the machine is built. There are, however, wider considerations.

America has the most money to contribute to such a project, but America's Congress has proved tight-fisted in the past. A decade ago, Congress killed a project called the Superconducting Super Collider that would have put the LHC in the shade. So what looks like a position of strength for American particle physics could actually be interpreted as a position of weakness. The result, however, might be the same—that instead of building the next accelerator in America because the Americans demand it, it gets built there as a way to keep American particle physicists in business. If Dr Aymar succeeds in making CERN into an organisation which has the strength of character to make a sacrifice like that, he will truly have shown himself to be a wizard.

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