The effect of beam thickness In a two-dimensional Cherenkov laser is i
nvestigated on the basis of the fluid model for the electron beam. In
the analysis, the transverse variation of the drift velocity for the e
lectron beam is taken into account. The numerical simulation shows tha
t there exists an optimum beam thickness for an efficient use of the e
lectron beam in the Cherenkov laser. (C) 1995 American Institute of Ph
ysics.