Industrial tooling and methods for the junctions of the superconducting busbars in the interconnections between the LHC cryomagnets (original) (raw)

2006, Journal of Physics: Conference Series

The Large Hadron Collider (LHC) is the next world-facility for the high energy physics community, presently under installation at CERN, Geneva. The main components of the LHC are the twin-aperture high-field superconducting cryomagnets that are powered in series by superconducting Nb-Ti cables. Along the machine, about 60 000 splices between superconducting busbars have to be performed in-situ during the interconnection activities. They are carrying a nominal current varying from 600 A to 13 kA in function of the powered magnetic elements, at an operating temperature of 1.9 K. Three specific techniques have been developed and optimised for the splicing of the three main types of cables: inductive and resistive soldering, ultrasonic welding. After a brief presentation of the constraints and requirements applying to these junctions, the tooling is described, highlighting the industrialisation aspects. Before their use to interconnect actual cryomagnets in the LHC tunnel, the equipment follow a rigorous qualification procedure to ensure that all the characteristics of the junctions (electrical, mechanical, reliability, quality control, etc) are within the specification. The assessment of the tooling performance is obtained via sample testing of superconducting busbars. Results are presented.