Observation and Cures of Wakefield Effects in the Slc Linac*

I c-. The acceleration and transport of beams with high currents and low emittances are very carefully controlled for the SLC Linacl. Both longitudinal and transverse wakefields affect strongly the trajectory and emittance corrections used for operations during collisions. Longitudinal beam loading introduces an internal energy spread. This loading produces the expected doubled peaked energy spectra while reducing the overall available energy for acceleration. Transverse wakefields cause rapid oscillation amplitude growth with injection errors but can be ameliorated with transverse wakefield (BNS) damping. Transverse wakefields cause an apparent change in the lattice strength, affecting the interpretation of lattice diagnostics. Oscillations also produce non-gaussian transverse density distributions, which must be controlled for emittance and background reduction. Finally, the small misalignments of the accelerating structure enlarge the emittances of the beam. They can be controlled through off-axis trajectories and through systematic waveguide movements.