CLIC Beam Delivery System Rebaselining and Long L* Lattice Optimization

This paper summarizes the re-optimization study made on the CLIC Beam Delivery System (BDS) in the framework of the rebaselining for beam collisions at 380 GeV for the initial energy stage. It describes the optimization process applied for the beam parameters as well as for the Final Focus system (FFS) lattice design with respect to the energy upgrade transition to 3 TeV. Both initial and final energy stages were optimized for a short (nominal) and a long L* (6 meters). The long L* option allows the last quadrupole (QD0) to be be located outward of the detector solenoid field influence. FFS optics designs based on the Local chromaticity correction and performance comparisons for both L* options are shown.