Novel Tunable Permanent Magnet Quadrupoles for the CLIC Drive Beam

Two novel designs have been generated for permanent magnet-based quadrupoles for the Compact Linear Collider (CLIC) drive beam. The advantages of reduced heat load in the accelerator tunnel and very low operating costs over conventional electromagnets are significant to the project, hence the motivation for developing these designs. The drive beam lattice requirements can be met using two magnet designs. The higher strength design, which reaches over 60 T/m, has been successfully prototyped, and this paper will report on the measured mechanical and magnetic performance of this magnet. The lower strength design (over 43 T/m) is complete, and a prototype magnet is now being assembled at Daresbury Laboratory. The design of this magnet will be described in detail in the paper.