Fermilab Today Friday, September 28, 2007

LHC triplet repairs complete

Fermilab Director Pier Oddone, CERN physicist Ranko Ostojic, Fermilab Deputy Director Young-Kee Kim, Fermilab physicist Peter Limon and Fermilab engineer Jim Kerby on a visit to a magnet assembly building at CERN in May 2007.
Credit: Tom Nicol, Fermilab

A team from CERN, Fermilab, Japan’s KEK Laboratory and Lawrence Berkeley National Laboratory have successfully completed repairs to all triplet assemblies at CERN’s Large Hadron Collider. The triplet components are now in the LHC tunnel for installation and testing. So far, three of eight triplets have been installed and successfully pressure tested in the tunnel. The remaining triplets are in the process of installation and pressure testing, to be followed by cooldown and powering in accordance with CERN’s LHC schedule.

The triplets, which include three superconducting quadrupole magnets and the associated cryogenic and power distribution boxes, or DFBXs, will focus particle beams prior to collisions at each of four interaction regions in the LHC when it begins operating in 2008.

The repairs addressed problems with superconducting magnet assemblies furnished by Fermilab. Internal support structures broke in one triplet during a pressure test on March 27. To effect the repair, teams attached sets of four metal cartridges to each magnet assembly to limit movement of the magnets inside their metal jackets or cryostats. The teams also fixed design problems in the DFBXs and in the attachments of magnets to the tunnel floor.

Upon completion of repairs to the final magnet, CERN physicist Ranko Ostojic, a section leader in CERN’s Accelerator Technology department with responsibility for superconducting magnets, congratulated the repair team.

“The Q1.L8 left for the tunnel this afternoon as planned,” Ostojic wrote in an email message to the team, translated here from French. “This magnet was repaired in record time, despite a few surprises that added to the normal operation. I want to thank you all for your effort and effectiveness in bringing these repairs to a successful close in an excellent atmosphere of collaboration.”

Fermilab Director Pier Oddone added his congratulations for the achievement, noting, however, that there is still work to do.

“Of course, we will not relax until all sectors are cold and fully powered,” Oddone wrote recently in Fermilab Today, Fermilab’s daily online newsletter. “Nonetheless, completing the repair is an important milestone. In achieving it, the collaboration between Fermilab and CERN has become even closer and stronger. At Fermilab we greatly appreciate the spirit of our CERN collaborators who rolled up their sleeves to help us repair the triplets with not a word expressing disappointment or recrimination.”

CERN Director General Robert Aymar agreed.

"The repair is now complete thanks to very efficient collaboration,"  Aymar said. "We are all very pleased  that we can now put this behind us and focus on getting ready for physics at the LHC next year."

LHC Magnet Update Archive

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