Third-order corrections to the SLC final focus

The minimum β achievable at the interaction point (β*) with the current design of the SLC final focus is limited to ~5 mm by third order optical aberrations, most notably the U₁₂₆₆ and U ₃₄₆₆ terms (using the notation of K. Brown). A new lattice is presented which effectively zeros these terms. The remaining third order terms which accrue from the interleaved sextupole pairs in the chromatic correction section (CCS) can be cancelled by the inclusion of five octupoles (two in the CCS, and three in the final telescope). The resulting final focus system is corrected to third order for any usable range of β* (given the constraints on the beam divergence at the interaction point). The potential luminosity obtainable from such a system is also presented