Limitation of the luminosity caused by the beam-beam interaction is one of
the major obstacles in future colliders. In order to suppress this interact
ion, there was proposed to intercept the colliding beams with a plasma at t
he interaction region. In this paper, the theory of plasma compensation of
beams' electric and magnetic fields is developed for arbitrary densities of
beams and the plasma. Because of nonlinear effects, the compensation is sh
own to depend on the charge of beam particles. The optimum plasma thickness
ensuring maximum suppression of the beam-beam effects is found. An analyti
cal expression for the compensation degree in the linear approximation in t
he case of a finite-thickness plasma is derived, and the criterion of appli
cability of the linear model is obtained. (C) 2000 Elsevier Science B.V. Al
l rights reserved.