The latest from the LHC

New test diagnostics are being developed to measure the electrical resistance of the copper component of the superconducting busbars, specifically within the interconnections that join the busbars together (see previous update) The first test is very precise but requires local access to the interconnection, which therefore needs to be open. A second test has been developed that can be performed externally using voltage tap connections. This allows the resistance of a 30-40m segment to be measured without opening interconnections. The two methods have been checked to give consistent results and can be used to identify the interconnections with the highest resistances, which are subsequently repaired. In parallel simulations and laboratory tests are also being carried out. All dipole interconnections in the four sectors have been measured at room temperature. Work is ongoing to measure the quadrupole lines, which have much longer busbar segments. A further test is currently being developed to be performed at cryogenic, but non-superconducting temperatures, to allow the rest of the machine to be checked.

The installation work on the pressure release ports of the inner triplets magnets has now been completed.