The largest particle accelerator in the world, the Large Hadron Collider was a bold multinational effort that cost billions of dollars and required some of the world's brightest minds.  However, this once glowing beacon of scientific progress became a massive mess not long after it went operational.

Coming online in September, the LHC blew a transformer that controlled its cooling in preliminary test firings.  Without the cooling, the LHC could not operate.  It was later found that a single bad solder was to blame for the failure, which not only blew out the transformer, but melted much of the attached circuitry.

Initially, the $21M USD repairs were expected to take a couple months at most.  This deadline was quickly pushed back in statements by CERN director Robert Aymar to April 2009 and then finally to the summer (June 2009).  Now the expected completion date for repairs has slid yet again. 

CERN spokesman James Gillies, surely beleaguered by having to bear all the bad news of late, broke the latest development on Friday.  He describes the new restart target date as "the late summer of 2009".

He described two plans for the LHC -- "Plan A" and "Plan B".  "Plan A" involves bringing the accelerator online in the late summer 2009, with lower power firings.  This plan would attempt to restore operation as early as possible, but at the cost of full functionality.  If you think "Plan A" sounds unattractive, try "Plan B"; "Plan B" would put the LHC out of commission until 2010 at the earliest.

"Plan B" would entail waiting until the LHC's pressure-relief system, the system of the accelerator that suffered from electrical failure, was totally replaced by an upgraded design.

For now, says Mr. Gillies, CERN will pursue "Plan A".  He states, "The priority is to get collision data from the experiment.  The LHC will run next year."

Under the current plan, only the three currently warmed segments of the eight total loop segments will be outfitted with the "fixed" pressure design.  Upgraded pressure-release valves will be installed in the cryostats on the dipole magnets for each of these three sections.  The remaining segments will not be warmed and will only receive the fix once they are warmed for other routine maintenance, sometime in the future.

The LHC design was supposed to produce an extremely powerful 7 tera electron-volts (TeV) beam, however it will be limited to 5 TeV or less, thanks to the problems.  Says Mr. Gillies, "The five undamaged sections can run at 5 TeV, and the rest of the machine can run at 4 TeV.  The highest we're hoping to run next year will be lower than 7 TeV."