Performance of prototypes and start up of series fabrication of the LHC arc quadrupoles

The construction of three prototype arc quadrupoles for the LHC machine has been concluded successfully. These magnets underwent warm and cold magnetic measurements as well as many other tests, both in CEA-Saclay´s laboratory and at CERN. Their training qualifies them for use in the LHC machine and their measured field quality points to only very minor corrections. An excellent correlation is found between warm and cold magnetic measurements. The prototype quadrupole design has been fully retained for the series fabrication of the 400 magnets and their cold masses by industry. This paper describes the main tests and measurement results of all three prototypes. It further explains the logistics for the manufacturing of the series of cold masses. These cold masses contain not only the main quadrupole but also different combinations of corrector magnets. Thus, together with variants imposed by the cryogenic configuration of the machine, 40 different types of cold masses have to be fabricated by the firm, to which the contract has been adjudicated