A Nonlinear Lens System to Smooth the Intensity Distribution of a Gaussian Beam

Abstract

The intensity distribution of a typical ion beam is quite nonuniform with a bright center and a diffuse edge; in many cases, the actual distribution is adequately approximated by a Gaussian distribution. However, many uses for such beams require uniform illumination from the center of the target to its edges. It is shown here that a system of controlled third-order aberrations produced by a pair of octupole magnets is able to sustantially smooth the intensity distribution by spreading the center and folding in the edges of the beam such that the intensity is nearly uniform over the entire target.