Construction and characterization of combined function quadrupoles

The magnetic lattice of the Brazilian Synchrotron Light Source uses combined function quadrupole magnets, i.e., special coils are included in the quadrupoles to produce a sextupolar field component. These combined quadrupoles are used in the dispersion free straight sections and the sextupolar component is employed in the minimization of geometrical aberrations produced by the chromatic correction sextupoles. The sextupolar component reaches 26 Tesla/m², superimposed on the main quadrupole component of 17 Tesla/m. The magnet core consists of laser cut steel laminations. In this report, we present results on mechanical and magnetic characterization of these magnets, including harmonic analysis and an investigation on the positioning repeatability of the magnetic axis with respect to the reference girder