February 6, 2009 11:38 PM
LHC may start up again in September
Matthew Chalmers, contributor
After spending a week in the French town of Chamonix thrashing out technical and logistical arguments (and fitting in the odd afternoon of skiing), 120 or so physicists from the CERN laboratory near Geneva have recommended a schedule for the restart of the Large Hadron Collider (LHC).
They say the 27-km machine will be ready for its first proton collisions at low energies in late 2009, and that it should be operated through the winter until autumn 2010 with a collision energy of 10 TeV to ensure the experiments collect enough data to get some new physics results.
Given that the LHC consumes as much electrical power as all the households in the region around Geneva, that will land CERN with an additional €8 million electricity bill if the recommendations from the Chamonix workshop are accepted by the lab's management on Monday.
"The workshop was absolutely phenomenal," says Steve Myers, CERN's director for accelerators and technology, who chaired the workshop.
Stories about LHC start-up dates may sound familiar. The €3 billion machine, which will smash protons into each other at unprecedented energies to study the deepest layers of physical reality, was billed to start up in 2007.
But a series of setbacks - including a poorly designed magnet built at Fermilab in the US and electrical connectors that bent when the machine was cooled to its -271 °C operating temperature and warmed up again - pushed that date back to 10 September 2008.
It turned out to be worth the wait: in just a few hours on the 10th, the team managed to get protons all the way around the ring in both directions, under the glare of the world's media.
But nine days later the machine broke, just before it was due to collide its first protons. An electrical fault ruptured part of its helium cooling system and caused significant collateral damage, requiring 53 of the LHC's magnets (each weighing tens of tonnes) to be brought to the surface (see a gallery of images showing the damage).
The repair job and protective measures, which are expected to cost CERN in the region of €20 million, were a major point of discussion at the Chamonix workshop. An early warning system involving 230 km of cables, designed to detect nano-ohm rises in electrical resistance in the superconducting wires that carry the enormous currents necessary to power the LHC's bending magnets, will be fully installed and tested before the machine switches on.
During one session of the workshop, however, physicists were unable to reach consensus about additional precautions that would see all magnets fitted with additional helium valves to reduce collateral damage in the event of a similar incident.
CERN is on a very tight budget, and the cost of electricity between December and February is three times more than it is in June. Yet the idea of turning the machine off just as it gets going is clearly unattractive. "We built this machine to operate it," says Myers. "If you buy a Rolls Royce, you can afford to put the petrol in!"
The official schedule will be decided on Monday. Will it be the last? "We're shooting for first injection of beam towards the end of September, with collisions four or five weeks later," says Myers. "It's ambitious, but we have a machine that's just raring to go."
The proposed timetable contains little room for slips, yet some 100 of the LHC's 1232 bending magnets will have to wait until September (when they are cold) before they can be retested.
Meanwhile, the doomsayers who allege the LHC may create planet-munching black holes are already crawling back out of the courtroom woodwork . . .
Posted: Thursday, February 05, 2009 5:19 PM by Alan Boyle
A worker prepares a replacement magnet for the Large Hadron Collider's ring.
The federal lawsuit against the world's largest particle-smasher may have been thrown out of court last year, but the plaintiffs have since filed an appeal, arguing that the judge was wrong when she said the U.S. legal system had no jurisdiction over the European science experiment.
The two plaintiffs, retired nuclear safety officer Walter Wagner and Spanish science writer Luis Sancho, had argued that full-scale operations at the Large Hadron Collider carried a risk of creating globe-gobbling black holes or other cosmic catastrophes. Those fears have been knocked down in a series of safety studies and research papers - including one that was put out just a couple of weeks ago.
Nevertheless, Sancho and Wagner are soldiering on.
Less than a month after U.S. District Judge Helen Gillmor dismissed the case in Honolulu back in September, the plaintiffs filed a notice of appeal with the 9th Circuit Court of Appeals in San Francisco. Their first brief in the case was due this week, and in that document, Sancho and Wagner take issue with Gillmor's ruling that the federal government did not play a major role in the European-led project. A copy of the brief was forwarded to me by James Tankersley, whose LHC Facts Web site is sympathetic to the plaintiffs' cause.
The brief rehashes the plaintiffs' worries about the collider. For a review of the scientific issues, you can check out this "Discovery or Doom" story, part of our special report on "The Big Bang Machine." But because the case was thrown out on legal rather than scientific grounds, the bulk of this week's brief dwells on the legal issues.
In a nutshell, the plaintiffs say the federal government's contribution of $531 million to LHC construction over more than 11 years, plus the U.S. consultative role on the project, are factors that add up to a "major federal action."
The judge ruled that the involvement was not a major federal action because the United States was not a voting member of Europe's CERN research council, and because the $531 million paled in comparison with CERN's $5 billion-plus contribution. (Most estimates currently run even higher, to a total construction cost of $10 billion.)
Judge Gillmor said that if the U.S. participation did not rise to the level of a major federal action, the federal court system did not have jurisdiction. At the end of her ruling, she strongly hinted that if the LHC's detractors wanted to stop U.S. involvement in the project, their main recourse should be to sway Congress. The plaintiffs, however, want the case to proceed in federal court.
The brief may be posted at some point to Wagner's LHCDefense Web site. Federal attorneys are due to file their own brief next month. Meanwhile, repairs are continuing on the LHC's magnet ring, which broke down shortly after its official startup in September. CERN says the repairs should be finished sometime this summer, leading to the collider's restart.
If this case follows the pattern set by Wagner's earlier challenges of the Relativistic Heavy-Ion Collider, the latest appeal is likely to be turned down on narrow legal grounds, perhaps even before the restart. There are likely to be multiple motions ahead, however.
In their brief, the plaintiffs say they want more hearings on the LHC's risks, and they won't be satisfied unless the LHC's experiments "can be proven to be impossible to destroy the Earth." The theoretical and experimental assurances that have been provided so far aren't good enough for them - and they may never be, when you consider how loath physicists are to say anything is absolutely impossible.