Progress on the CLIC final focus system

The final focus system has been adapted to the revised parameter list for CLIC (CERN Linear Collider). It is expected that lower emittances are obtainable in the damping rings and the blowup in the main linac can be contained to 25%. In that case the luminosity would no longer be limited by synchrotron radiation in the final quadrupoles, and a luminosity above 10/sup 33/ cm/sup -2/ s/sup -1/ could be reached for bunches colliding head on. However, finite crossing angles are required so the disrupted beam can pass through a special aperture in the first interaction region quadrupole. The reduction of luminosity due to this crossing angle and due to unavoidable misalignments has been studied as a function of bunch length with a particle tracking code. Two designs of quadrupoles are being evaluated.<
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