The countdown to the startup of the world's most powerful particle collider has begun with today's announcement that the first beam of protons will be sent all the way through the 17-mile-round Large Hadron Collider on Sept. 10.

A key phase of the final preparations for the $10 billion project begins this weekend, when Europe's CERN particle-physics center begins testing the last links in the high-powered chain of magnets that will eventually send beams shooting through the collider's ring with the energy of a bullet train. During this weekend's tests, low-intensity protons will be injected into a small section of the collider and zip around one-eighth of the ring.

The tests will grow in strength and complexity all the way up to "Red Button Day."

If the schedule holds, the collider on the French-Swiss border will make a splash at 9 a.m. local time (3 a.m. ET) Sept. 10, a week after a federal judge in Hawaii begins hearing a motion to dismiss a civil lawsuit claiming that the device could destroy the world. Over the past few months, scientists at CERN (and the federal government) have laid out their case that a globe-gobbling catastrophe could never happen. Nevertheless, the court proceedings could provide a sideshow for the main event. Or they could be finished up by that time.

Here's the relevant section from CERN's news release about the startup:

"CERN has today announced that the first attempt to circulate a beam in the Large Hadron Collider (LHC) will be made on 10 September. This news comes as the cooldown phase of commissioning CERN's new particle accelerator reaches a successful conclusion. Television coverage of the start-up will be made available through Eurovision.

"The LHC is the world's most powerful particle accelerator, producing beams seven times more energetic than any previous machine, and around 30 times more intense when it reaches design performance, probably by 2010. Housed in a 27-kilometer tunnel, it relies on technologies that would not have been possible 30 years ago. The LHC is, in a sense, its own prototype.

"Starting up such a machine is not as simple as flipping a switch.

"Commissioning is a long process that starts with the cooling down of each of the machine's eight sectors. This is followed by the electrical testing of the 1,600 superconducting magnets and their individual powering to nominal operating current. These steps are followed by the powering together of all the circuits of each sector, and then of the eight independent sectors in unison in order to operate as a single machine.

"By the end of July, this work was approaching completion, with all eight sectors at their operating temperature of 1.9 degrees above absolute zero (-271 degrees C). The next phase in the process is synchronization of the LHC with the Super Proton Synchrotron (SPS) accelerator, which forms the last link in the LHC's injector chain. Timing between the two machines has to be accurate to within a fraction of a nanosecond. A first synchronization test is scheduled for the weekend of 9 August, for the clockwise-circulating LHC beam, with the second to follow over the coming weeks. Tests will continue into September to ensure that the entire machine is ready to accelerate and collide beams at an energy of 5 TeV [trillion electron volts] per beam, the target energy for 2008. Force majeure notwithstanding, the LHC will see its first circulating beam on 10 September at the injection energy of 450 GeV (0.45 TeV).

"Once stable circulating beams have been established, they will be brought into collision, and the final step will be to commission the LHC's acceleration system to boost the energy to 5 TeV, taking particle physics research to a new frontier.

"'We're finishing a marathon with a sprint,' said LHC project leader Lyn Evans. 'It's been a long haul, and we're all eager to get the LHC research program under way.' ..."

CERN then lays out the accreditation procedures for journalists wanting to cover the startup, and notes that the event will be Webcast as well.

Red Button Day will be the big media day for the collider: The BBC, for example, plans to broadcast all day from CERN. However, it will take weeks more to get the proton beams in working order and bring collisions up to the 5 TeV level. That's why CERN has scheduled the big party for dignitaries (like French President Nicolas Sarkozy, for example) well after Red Button Day, on Oct. 21.

The collider isn't expected to reach its full power of 14 TeV until 2009 or 2010. As I noted earlier this week, that could leave a window for Fermilab's Tevatron in Illinois to steal some of the LHC's thunder - perhaps by making the first detection of the Higgs boson, the last fundamental particle predicted by current theory that has not yet been found. The Higgs boson (a.k.a. "the God Particle") is thought to play a key role in determining the properties of particle mass.

Even if the Tevatron finds the Higgs, it will be up to the LHC to study the particle in depth - and plumb other mysteries of the universe, ranging from the nature of dark matter and black holes to the possibility of extra dimensions in space.

For further background on the LHC and other frontiers of physics, check out the following dispatches - and stay tuned for our upcoming big-picture look at the big-bang machine:

"We must BE the change we wish to see in the world"-Gandhi