CHARGE CONTROL DEVICE FOR A SYSTEM WITH MULTIPLE ELECTRON BEAMS

Systems and methods to focus and align multiple electron beams are disclosed. A camera produces image data of light from electron beams that is projected at a fiber optics array with multiple targets. An image processing module determines an adjustment to a voltage applied to a relay lens, a field lens, or a multi-pole array based on the image data. The adjustment minimizes at least one of a displacement, a defocus, or an aberration of one of the electron beams. Using a control module, the voltage is applied to the relay lens, the field lens, or the multi-pole array.