Production and Quality Assurance of Main Busbar Interconnection Splices During the LHC 2008-2009 Shutdown

The main busbar interconnection splices of the Large Hadron Collider are assembled by inductive soldering of the Rutherford type cables and the copper profiles of the stabilizer. Following the September 2008 incident, the assembly process and the quality assurance have been improved, with new measur...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:IEEE transactions on applied superconductivity 2011-06, Vol.21 (3), p.1786-1790
Hauptverfasser: Bertinelli, F, Bottura, L, Dalin, J.-M, Fessia, P, Flora, R H, Heck, S, Pfeffer, H, Prin, H, Scheuerlein, C, Thonet, P, Tock, J.-P, Williams, L
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The main busbar interconnection splices of the Large Hadron Collider are assembled by inductive soldering of the Rutherford type cables and the copper profiles of the stabilizer. Following the September 2008 incident, the assembly process and the quality assurance have been improved, with new measurement and diagnostics methods introduced. In the 2008-2009 shutdown the resistance both in the superconducting and in the normal conducting states have been the focus for improvements. The introduction of gamma radiography has allowed the visualization of voids between cable and stabilizer. It is now known that during the standard soldering heating cycle solder is lost from the busbar extremities adjacent to the splice profiles, leaving parts of the cable in poor contact with the stabilizer. A room temperature resistance measurement has been introduced as a simple, non-destructive test to measure the electrical continuity of the splice in its normal conducting state. An ultrasonic test has been performed systematically in order to verify if the vertical gaps between the splice profiles are filled with Sn96Ag4 solder. Visual inspections of the different splice components before and after interconnection have been reinforced. The additional information gained has allowed targeted improvements in the splice production process. Ad-hoc machining of splice components avoids macroscopic gaps, additional soldering foil and copper shims are used in critical areas in order to improve the cable to stabilizer contact.
ISSN:1051-8223
1558-2515
DOI:10.1109/TASC.2010.2085072