Paper | Title | Page |
---|---|---|
MOPEB044 | High-current Bus Splice Resistances and Implications for the Operating Energy of the LHC | 373 |
|
||
At each interconnection between LHC main magnets, a low-resistance solder joint must be made between superconducting cables to provide a continuous current path through the superconductor, and between the surrounding copper stabilizer to provide a current path in case the cable quenches. About 10,000 such joints exist in the LHC. An extensive campaign has been undertaken to characterize and map the resistances of both types of joints. All of the superconducting cable splices were measured using the enhanced protection system of the LHC superconducting circuits. No high-resistance superconductor splices were found above 3 nano-Ohms. Non-invasive measurements of the stabilizer joints were made at 300K in 5 of the 8 sectors, and at 80K in 3 sectors. More precise local measurements were made on suspect interconnects that were opened up, and poor joints were repaired. However, it is likely that additional imperfect stabilizer joints still exist in the LHC. A statistical analysis is used to place bounds on the remaining worst-case resistances. This sets limits on the maximum operating energy of the LHC, prior to a more extensive intervention. |