CERN says its almost ready to turn on Large Hadron Collider

William Atkins
Saturday, 20 June 2009 18:46

Science - Energy

Before the LHC becomes operational, sector 4-5 is being investigated for a questionable splice.

The CERN press release states, “Sector 4-5 has been measured at a temperature of 80 K [Kelvin], indicating at least one suspect splice. By warming the sector, the results of this measurement can be checked at room temperature, thereby confirming the reliability of testing at 80 K.”

“If the 80 K measurements are confirmed, any suspect splices in this sector will be repaired. More importantly, validation of the 80K measurements will allow the splice resistance in the last three sectors to be measured at this temperature, thereby avoiding the time needed for re-warming.”

“The measurements in these sectors will provide the information needed to determine the start-up date and initial operating energy of the LHC in the range 4-5 TeV [teraelectron volts, or one billion electron volts], since running at 4 TeV should be possible without further repairs, whereas 5 TeV could require extra work to be done.”

“A key part of the modifications being made to the LHC is the so-called quench protection system (QPS), which triggers evacuation of the stored magnetic energy quickly and safely should a part of the LHC’s superconducting system warm up slightly and cease to be superconducting. Following the September incident, a new enhanced QPS system was designed and is presently under construction."

"The new system will be fully tested and operational in late summer 2009. This new system will protect the LHC from incidents similar to that of 19 September 2008.”

Besides these improvements new pressure relief valves are being installed, an improved ultra-high vacuum system is being installed, and the anchoring system for the LHC magnets are being strengthened.

This schedule, if successful, will permit running of the LHC for the rest of 2009, with a break over Christmas, and then continued running into the fall of 2010 so that scientists will have access to it during these times.

The home page of the LHC is: http://lhc.web.cern.ch/lhc/.

Additional information on the LHC is found within a series of articles on the CERN/LHC website: http://lhc.web.cern.ch/lhc/News.htm.