Powering Tests and Magnet Training

In this paper the powering tests and magnet training during the hardware commissioning campaigns of Run 2 are discussed, and the implications of running at 7 TeV from a magnet training and reliability perspective are given. During Run 2, the efficiency of powering tests has steadily increased due to enhanced control software, more automatic analysis, and more experienced CERN personnel. The MP3 Intervention Matrix, used for documenting requalification procedures after interventions, is presented. Given that the main dipole circuits are considered the main bottleneck for reaching 7 TeV operation from a magnet training perspective, training of these circuits is discussed in detail with regards to training efficiency and electrical integrity. The training campaign of December 2018 comprised training of the main dipole circuit in sector 12, all main quadrupole circuits, the individually powered dipoles and quadrupoles, and the inner triplets of points 1 and 5. Due to time constraints, the training targets were only partially reached. In general the observed training behavior was encouraging, although training on the main dipole circuit in sector 12 was slower than expected. Also considering that all dipoles have previously reached a quench current of at least 12 kA before installation into the LHC, no showstopper was identified for reaching 7 TeV operation. With regards to reliability of magnet operation at 7 TeV, no problems are expected in terms of flattop quenches, but the sensitivity to UFO-induced quenches is expected to increase significantly.