The latest from the LHC

12-02-2009.

On the surface, a dipole has been fully fitted and tested with a new helium pressure-relief valve. Work will start this week to fit these new devices to the remaining magnets on the surface and by next week the campaign to install the relief valves in situ in the tunnel will start in the warmed-up sectors.

In SM18 the cold-testing team have found a new method of testing for internal splice- resistance with 20 times the accuracy of previous methods. They can now measure the individual splice resistance to 1 nano-ohm.

A massive campaign has also been launched to re-analyse data taken from all superconducting magnets that have already gone through cold testing but were not checked for abnormal splice-resistance. By combining two different sets of data taken for other purposes during the magnet cold-testing the new analysis will be able to infer if there was any abnormal internal resistance. The work is being carried out by a collaboration of the TE, EN and PH departments.

During the incident in sector 3-4 the pressure of released helium on the vacuum barriers caused some of the short straight sections (SSS) to be moved from their anchoring. Designs have been approved for a new system to reinforce the anchoring of SSS that have vacuum barriers. This new system will be installed in all 8 sectors (104 systems).

Sector 6-7 is currently being warmed and it is expected that the dipole with high resistance (approximately 50 nano-ohms) will be ready to be removed from the tunnel by the end of February.

 

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