Results From the ALICE Dipole Magnet Commissioning

Abstract

The ALICE experiment is being installed in point 2 of the future LHC at CERN. The experimental hall was previously used by a LEP experiment of which ALICE reuses the big L3 solenoid as the central detector magnet. The single arm forward muon spectrometer requires in addition a new dipole magnet with a very large aperture. This magnet has been developed and constructed and has now been installed in its final position. Since this location adjacent to the large L3 solenoid leads to important interference between both devices the dipole has previously been assembled and tested in a pre-assembly location before the final assembly and commissioning in 2005. The techniques and results of geometrical, thermal, electrical, magnetic and mechanical measurements in the final location are presented. These values are also compared to those measurements obtained during the pre-commissioning campaign when the magnet was tested in a stand-alone position. To provide the necessary data for the particle track analysis, the magnetic field of both magnets has been mapped in the entire detector space and also in the surrounding region where field sensitive electronics will be installed. Some relevant results are summarized