Positive-Space-Charge Lens for Focusing and Manipulating High-Current Beams of Negatively Charged Particles

Abstract

We describe a new approach for the creation of effective axially symmetric plasma tools for focusing and manipulating high-current negatively charged particle beams, negative ions, and electrons. This approach is based on the fundamental plasma-optical concept of magnetic and electrostatic insulation of electrons and nonmagnetized positive ions providing controlled uncompensated positive-space-charge cloud formation. The recent advances in the creation of negative ion sources have led to the problem of elaboration and creation of focusing tools capable of manipulating high-current negative ion beams. We describe novel experimental, theoretical, and computer simulation results of the application of the magnetic electron insulation concept for the creation of the positive-space-charge electrostatic plasma lens. The described results open up an attractive possibility to use this lens for focusing high-current negative ion beams.