A new method of correcting the trajectory in linacs

The authors describe a novel method of reducing the transverse emittance dilution in linear colliders due to both transverse wakefields and dispersive errors. The technique is a generalization of the dispersion-free (DF) correction algorithm; the dilutions are corrected locally by varying the beam trajectory. This technique complements BNS (Balakin-Novokhatsky-Smirnov, 1983) damping, which primarily corrects the dilutions resulting from coherent betatron oscillations. The results of simulations are presented, demonstrating the viability of the technique. Since the proposed technique is very similar to the DF method, the authors know that it is a robust algorithm and is not sensitive to effects such as jitter and calibration errors. Furthermore, the technique will effectively decouple the emittance dilution from the transverse alignment of the quadrupoles and the beam position monitors.<>