Field Quality of the First LHC Pre-series Dipoles

This note reports the main results on the field quality measured at cold in the first eighteen pre-series LHC dipoles during the years 2001-2002. The main results concerning the integrated dipole field, the magnetic length and the field angle are presented. The harmonics values at injection and nominal field are compared to the constraints in multipoles as specified for the accelerator. The contribution relative to the geometry of the coils is analyzed as well as the correlation between warm and cold measurements. The errors originating from the yoke saturation at high field, from the magnetization of the superconductor and from time dependent effects at field corresponding to beam injection are also presented.