Construction Accidents and Delays
- On 25 October 2005, José Pereira Lages, a technician, was killed in the LHC when a switchgear that was being transported fell on him.
- On 27 March 2007 a cryogenic magnet support broke during a pressure test involving one of the LHC's inner triplet (focusing quadrupole) magnet assemblies, provided by Fermilab and KEK. No one was injured. Fermilab director Pier Oddone stated "In this case we are dumbfounded that we missed some very simple balance of forces". This fault had been present in the original design, and remained during four engineering reviews over the following years. Analysis revealed that its design, made as thin as possible for better insulation, was not strong enough to withstand the forces generated during pressure testing. Details are available in a statement from Fermilab, with which CERN is in agreement. Repairing the broken magnet and reinforcing the eight identical assemblies used by LHC delayed the startup date, then planned for November 2007.
- Problems occurred on 19 September 2008 during powering tests of the main dipole circuit, when an electrical fault in the bus between magnets caused a rupture and a leak of six tonnes of liquid helium. The operation was delayed for several months. It is currently believed that a faulty electrical connection between two magnets caused an arc, which compromised the liquid-helium containment. Once the cooling layer was broken, the helium flooded the surrounding vacuum layer with sufficient force to break 10-ton magnets from their mountings. The explosion also contaminated the proton tubes with soot. This accident was thoroughly discussed in a 22 February 2010 Superconductor Science and Technology article by CERN physicist Lucio Rossi.
- Two vacuum leaks were identified in July 2009, and the start of operations was further postponed to mid-November 2009.
Read more about this topic: Large Hadron Collider
Famous quotes containing the words construction, accidents and/or delays:
“Striving toward a goal puts a more pleasing construction on our advance toward death.”
—Mason Cooley (b. 1927)
“The day-laborer is reckoned as standing at the foot of the social scale, yet he is saturated with the laws of the world. His measures are the hours; morning and night, solstice and equinox, geometry, astronomy, and all the lovely accidents of nature play through his mind.”
—Ralph Waldo Emerson (1803–1882)
“What should concern Massachusetts is not the Nebraska Bill, nor the Fugitive Slave Bill, but her own slaveholding and servility. Let the State dissolve her union with the slaveholder.... Let each inhabitant of the State dissolve his union with her, as long as she delays to do her duty.”
—Henry David Thoreau (1817–1862)