Dynamic Collimation for Linear Colliders

Experience with the SLC has indicated that backgrounds caused by the tails of the transverse beam distribution will be a serious problem for a next generation linear collider. Mechanical scrapers may not provide the best solution, because they may be damaged by the tiny, intense beams, and dso because they may induce wakeiIeld kicks large enough to cause emittance dilution. In this paper, we present a possible solution, which uses several n&linear lenees to drive the tails of the beam to large amplitudes where they can be more easily scraped mechanically. Simulations of several different schemes are presented and evaluated with respect to effectiveness, tolerances and wake&Id effects.