Measurements of the Resistance of Main Circuit Busbar Segments at the LHC at Warm

Following the QPS review in February 2009, a potential source of problems with the main circuit bus bar splices was identified: discontinuity in the copper stabilizer, coupled with lack of contact of the superconducting cable to the copper, in the vicinity of a splice. A campaign was launched to measure all such cases in the LHC. Non-invasive measurements were performed at room temperature or at about 80K in all sectors. A number of splices, following an indication obtained from these measurements, were opened and repaired. The resistance of these splices was also measured before and after the repair. We here present the results of this measuring campaign, together with the analysis that estimates the highest splice resistance left in the machine, which is a limiting factor to the maximum safe energy at which the LHC can operate