|arya||Date: Thursday, 14-February-2013, 8:18 PM | Message # 1|
|By Jason Palmer Science and technology reporter, BBC News |
The Large Hadron Collider has turned off its particle beams ahead of a shut-down period that will last two years.
The particle accelerator is best known for identifying a particle believed to be the Higgs boson in late 2012.
But following technical faults shortly after it first switched on, the machine has never been run at the full energies for which it was designed.
A programme of repairs and upgrades to the accelerator and its infrastructure should allow that in late 2014.
The LHC's beams were "dumped" early on Thursday morning, but it will take until Saturday morning for the machine's 1,734 magnets to warm up to room temperature.
Then an unprecedented period of upgrade and repair - dubbed "Long Shutdown 1" - will begin.
The machine ran at particle energies of 8 trillion electron-volts (teraelectronvolts; TeV) in 2012, up from the prior high point of 7TeV in 2011.
But when the shutdown concludes, slated for the end of November 2014, it should be set to run at 14TeV - far and away the highest-energy collisions ever attempted by scientists.
"We have been running successfully, but only at half the maximum energy, because we can only safely run the magnets at half the design current," said Tony Weidberg, a University of Oxford physicist who works on the LHC's Atlas detector.
The problem has been the connections between the giant magnets that help steer charged particles around the LHC's 27km-long ring.
Read more/Full article/source - http://www.bbc.co.uk/news/science-environment-21421460