The latest from the LHC

Work to consolidate the planning of surface and tunnel activities for both magnet and non-magnet related tasks is going ahead.

Dipole MB2334, which was found to have an internal splice resistance of 100 nano-ohms and was removed from Sector 1-2 last week, has now been de-cryostated and the cold mass is being opened.

In the warm sectors (1-2 and 5-6), shutdown activities and RF ball testing of the beam pipes has been taking place. The RF ball containing a transmitter is propelled down the beam pipe by a flow system in order to check the "plug-in" modules (PIMs), which are responsible for the continuity of the electrical circuit of the vacuum chamber. The PIMs, specifically some of their RF fingers, can sometimes be damaged during the warm-up due to the expansion of the magnets.

The RF ball testing in Sector 1-2 is now complete, with both beam pipes checked. Three PIMs have been identified with buckled RF fingers, which are now being replaced. The testing is currently ongoing in Sector 5-6. For more information on RF ball testing please see the previous Bulletin article.