Quadrupole-free detector optics design for the Compact Linear Collider final focus system at 3 TeV

Aiming to simplify the machine detector interface of the Compact Linear Collider (CLIC), a new detector model has been designed allowing the last quadrupole QD0 of the final focus system (FFS) to be located outside of the experiment with a distance L* from the interaction point of 6 m. In this paper, the beam delivery system (BDS) has been reoptimized, offering a luminosity performance that exceeds the design requirements by 11% for the total luminosity and by 7% in the energy peak. A simulation campaign has been carried out and has proved the feasibility of recovering the luminosity under realistic transverse misalignments of the FFS optics, by means of different orbit and aberration correction techniques, making this long L* design a realistic candidate for the future CLIC BDS.