Cryogenic and Mechanical Measurements of the first two LHC Lattice Quadrupole Prototypes

In the framework of a collaboration agreement between CERN and CEA in Saclay, France, two twin aperture quadrupole prototype magnets have been constructed at Saclay. These magnets of 3.05 m length which have a coil aperture of 56 mm and a nominal gradient of 252 T/m at 15060 A have been tested and measured at superfluid helium temperatures in a specially adapted horizontal test cryostat in Saclay. The magnets are instrumented allowing to investigate their behaviour during cool-down, operation and warming up. The paper presents a summary of the cryogenic measurement results including temperature and pressure. Further, quench data and the results of strain gauge measurements on the collars and of displacement transducers are described. 1. LNTR~DUCTI~N The collaboration between CERN and CEA/Saclay for the work on the lattice superconducting quadrupole magnets for the LHC started end of 1989. The magnetic parameters were frozen in July 1990, followed by the detailed design [I] and fabrication of tooling and components. Two cold masses, i.e two twin quadrupoles mounted in their helium vessel, have been assembled [2] and were ready to be tested mid 1993. Numerous tests were carried out before and during the assembly of the magnets [3]. However, the final proof of magnet performance is obtained by the cold tests. This paper describes these tests and their results for the two cold masses. ~.BRIEFDESCRIFTIONOF THEMAGNETS. 2.1 Main parameters. The main parameters, choosen in 1990, correspond to a 15 TeV collision energy for the protons of the LHC and to a field of 10 T for the superconducting dipole magnets. Table 1 lists the main parameters and figure 1 shows the cross section of the cold mass. Reference [l] gives a full description of the magnets.