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The Field Quality Crisis Unit of the LHC main dipoles production

This informal group is activated when magnetic measurements at room temperature of the field quality in the main LHC dipoles show anomalies. It gathers project engineers, technicians, magnet measurers, and analysists. In this page we keep track the crisis that has been undergone during the LHC dipole production as far as field quality is concerned, decisions that have been taken, and acquired experience. We acknowledge V. Remondino and J. Billan for the instrumentation for magnetic measurements and all the technicians of the LHC-MMS-IF section (now in AT-MTM) for carrying out measurements at the manufacturers. Measurements at 1.9 K provided by L. Bottura L. Deniau and S. Sanfilippo (AT-MTM-AS).

Disclaimer: Please note that these measurements are the result of the efforts and collaboration of many people. However these results are not final. You can consult data, but before using them you are kindly requested to ask the permission to the authors.

Closed cases:

The double coil protection sheet in collared coil 2002

Cold welds in the cables of cryomagnet 1005

A missing shim in 1027

Inner radial shift of a conductor block in collared coil 1099

Feedback on magnetic length

Calibration of integrated main field

Inner radial shift of a conductor block in collared coil 2032

Inner radial shift of a conductor block in collared coil 2035

Inner radial shift of a conductor block in collared coil 2065

Inner radial shift of a conductor block in collared coil 2084

Inner radial shift of a conductor block in collared coil 2089

Inspection of CC 2092 during de-collaring procedure (due to QH problems)

Inner radial shift of a conductor block in collared coil 3135

Inner radial shift of a conductor block in collared coil 3175