A resolving aperture assembly for an ion implantation system has a first plate and a second plate, where the first plate and second plate generally define a resolving aperture therebetween. A position of the first plate with respect to the second plate generally defines a width of the resolving aperture. One or more actuators are operably coupled to one or more of the first plate and second plate and are configured to selectively vary the position the first plate and second plate with respect to one another, thus selectively varying the width of the resolving aperture. A servo motor precisely varies the resolving aperture width and a pneumatic cylinder independently selectively closes the resolving aperture. A downstream position actuator varies a position of the resolving aperture along a path of the ion beam, and a controller controls the one or more actuators based on desired properties of the ion beam.