Optimum plasma lens for focussing of high-current ion beams

Summary form only given, as follows. Optimum plasma lens realized in experiments at weak magnetic fields, when the Larmor radius of electrons is comparable with radius of the lens, has been theoretically researched. The optimum lens is lens, in which the vortical perturbations are not excited and particle density in which is uniform in space. Three possible reasons not excitation of vortices in near axis area of the high-current plasma lens have been researched namely, finite time of ion movement through the plasma lens, finite time of electron renovating in it, proximity of the plasma lens parameters to optimum ones.