Optimization of Electromagnetic Design After Winding Tests for the Nb3Sn Cos-Theta Dipole Model for FCC-hh

The Future Circular Collider in hadron-hadron configuration (FCC-hh) is one of the main options for the post-LHC era of particle accelerator. The project led by CERN aims to build a 100 km-long collider with 100 TeV of center-of-mass energy, using bending dipoles able to achieve a bore field > 14 T. The Istituto Nazionale di Fisica Nucleare (INFN) and CERN are collaborating to construct a Nb3Sn cos-theta dipole model, to increase the R & D efforts for high-field superconducting magnets technology, according to the updated European Strategy for Particle Physics. Here we give an update on the intense design activity, and we report the results of the first winding trials performed with a dummy conductor, to experimentally validate the magnet design and start the iterative process to optimize the manufacturing method. The results of the first winding tests are shown in the paper, focusing on the impact of the coiling procedure on the mechanical behavior of the unreacted Nb3Sn Rutherford cable.