IMPROVEMENT OF THE ACTIVE CYLINDRICAL PLASMA LENS CONCEPT BY A TAPERED DISCHARGE GEOMETRY

Recently an active current carrying plasma lens was introduced using a wall-stabilized discharge mode with remarkable focusing properties fo r high energy heavy ion beams, Tn this paper, a further improvement of focusing performance of a wall-stabilized plasma lens will be reporte d using a tapered geometry, The gradient of the focusing held is incre ased in approximate to direction and the focusing power is increased c ompared to a cylindrical lens with the same length and discharge curre nt, Aberration effects of this tapered lens were minimized by optimizi ng both shaping and discharge conditions. With the tested lens an argo n ion beam of 15.4 MeV/amu was focused from an initial diameter of 10 mm down to a spot size of 160 mu m. The results of the focusing experi ments are compared with optical plasma diagnostics data allowing for a n interpretation of the observed Focusing behavior.