Upgrade of the Automatic Measurement System for the Electrical Verification of the LHC Superconducting Circuits

Electrical quality assurance (ELQA) of the superconducting electrical circuits in the LHC requires an advanced test equipment accompanied by the dedicated software, data storage system, and analysis toolset. In 2007, the measurement system was built to carry out the Test Procedure 4 (TP4), namely the qualification of the whole superconducting circuits in terms of instrumentation routing, insulation quality, resistance, and impedance of the circuit components. This measurement system has become the main ELQA tool at the LHC. During the testing campaign at LHC from 2007 to 2009, a set of new functionalities was proposed. For the Long Shutdown 1 of the LHC that was planned for 2013–2015, the number of the measurement systems had to be increased from the existing four to eight units. In view of these facts, in 2010, the decision was made to perform the upgrade of the TP4 system. In this paper, we describe the requirements, the upgrade process, the architecture, and parameters of the upgraded system, including the maintainability improvements. We also present examples of the automated electrical tests of the LHC superconducting circuits performed with the upgraded TP4 system during LHC Long Shutdown 1, which show high flexibility and extendibility of the implemented solution.