Speaker
Description
We report on the results of magnetic measurements, in particular, of the first short models of twin-aperture magnets for the CERN Future Circular Collider (FCC-ee) arcs. To date, we have built and tested three 1-m long bending magnets, using different materials for the ferromagnetic yoke and a 1-turn vs. multi-turn excitation. Besides the interest in checking the unusual I-layout, the focus is also on the behavior at low field, down to about 10 mT in the gap, and its impact on field quality (in particular, on the gradient term). In parallel, we have also worked on a 1-m long quadrupole model, with the aim of testing the peculiar twin configuration and assessing the multipole field errors as a function of the excitation current, checking especially the dipole and sextupole components. The results presented can be the basis of further developments for this kind of magnets.
