Patent ID: 6396223
Filing Date: 2002-05-28
Classification: H01J

Abstract:
A cusp filter for altering a multi-species plasma to separate ions of a first mass (M1) from ions of a second mass (M2) which comprises:a first magnetic assembly for generating a first magnetic field having a magnitude, B, with magnetic field lines oriented in a first direction along an axis; a second magnetic assembly for generating a second magnetic field having a magnitude substantially equal to B, and having magnetic field lines oriented in a second direction along said axis, said second magnetic field opposing said first magnetic field to establish a null cusp oriented substantially perpendicular to said axis between said first and second magnetic fields; and an injector for directing the ions (M1) and the ions (M2) with respective energies along said axis toward said null cusp to divert the ions (M1) away from the axis and prevent them from crossing said null cusp, while allowing the ions (M2) to cross the null cusp and proceed along said axis through said filter.