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March 25, 2013
(Click on the image for enlarge)
Image above: Some of the main consolidation work to be carried out on the LHC during the long shutdown. (Image: CERN).
For its first three years of running, the Large Hadron Colllider (LHC) has been operating below its design capacity of 14 TeV.
Though the 27-kilometre collider provided enough collisions for CERN experiments to find a Higgs boson in 2012, due to the mechanical damage and helium leak of 2008, it has not yet reached its full potential.
The LHC is in its first long shutdown and undergoing a process called "consolidation," which means that engineers and maintenance crews are repairing and strengthening the accelerator elements in preparation for running at higher energy in 2015.
The Large Hadron Collider "LHC" (red circle). Credit: Orbiter.ch Aerospace - Flight Dept.
Over the next few months, CERN will be producing a series of videos to explain each step of this process. The videos will detail the jobs that must be completed in order to boost the LHC into higher gear. See the diagram above for an overview.
These tasks include testing and replacing some of the LHC’s main dipole and quadrupole magnets, which are used to bend the paths of the particles and keep them tightly bunched; adding reinforcing “shunts,” to the current-carrying splices between the magnets; conducting tests to detect any irregularities in the magnets or imperfections in the electrical insulation; and a range of other work to improve the machine.
"Get connected: Consolidating LHC splices"
On 19 September 2008, during powering tests on the Large Hadron Collider (LHC), a fault occurred in a superconducting interconnection between two magnets – a dipole and a quadrupole – resulting in mechanical damage and release of helium from the magnet cold mass into the tunnel. Proper safety procedures were in force, the safety systems performed as expected, and no-one was put at risk. But the fault did delay work on the LHC by six months.
After the incident, CERN engineers decided that such interconnections should be upgraded to avoid similar electrical faults in future. As a precaution, beams in the LHC were accelerated below the LHC's design limit for the first three years of running. Upgrading the interconnections will be one of the main activities at the LHC during its two-year shutdown, allowing the LHC to run at 7 TeV per beam when it starts up again.
There are 10,000 "splices" – superconducting connections between magnets – on the LHC. Each splice carries 13,000 amps.
In the video above, Jean-Phillipe Tock of the Technology department explains how, over the next 18 months, technicians will add an additional piece – a "shunt" – to each splice. The shunt is a low-resistance connection that forms an alternative path for a portion of the current in the event that the splice loses its superconducting state. A total of 27,000 shunts will be installed in the 27-kilometre accelerator.
Note:
CERN, the European Organization for Nuclear Research, is the world's leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a candidate for accession. Israel is an Associate Member in the pre-stage to Membership. India, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.
More like this:
Get connected: Consolidating LHC splices 19 Mar 2013: http://home.web.cern.ch/about/updates/2013/03/get-connected-consolidating-lhc-splices
Related links:
Large Hadron Colllider (LHC): http://home.web.cern.ch/about/accelerators/large-hadron-collider
Helium leak of 2008: http://press.web.cern.ch/press-releases/2008/10/cern-releases-analysis-lhc-incident
For more information about CERN, visit: http://home.web.cern.ch/
Images, Video, Text, Credits: CERN / Kelly Ann Izlar / Cian O'Luanaigh / Orbiter.ch Aerospace - Flight Dept.
Best regards, Orbiter.ch
