Luminosity enhancement by focusing and colliding beams in a plasma.

The potential gain of luminosity by both focusing and colliding e+ebeams in an underdense plasma is investigated. We first suggest the possibility of creating the plasma by the beam self-induced “tunneling ionization” of a gas. We then study the beam optics in the continuous focusing environment provided by the plasma, and the subsequent e + e beam-beam interaction in the same plasma. When applied to a range of beam parameters based upon the present SLC conditions, we find that a gain by more than a factor 10 in luminosity is possible. The sensitivity of various non-ideal situations is discussed. Submitted to Phys. Rev. D * Work supported by Department of Energy contract DE-AC03-76SF00515.