Abstract
This investigation was undertaken to determine the feasibility of using a computer system to control the position of a focused ion beam on a target. A Van de Graaff generator, with a capability of 2 MV, was used to supply a beam of protons at a current of approximately 100 nA. To obtain results in the short time available the beam position sensing was crude, comprising a 10 by 10 wire array over an area of 1cm[2]. , and all beam movement was completely derived from the computer. The overall system proved workable and simple patterns could be drawn on the wire grid. The main problems proved to be beam energy and current stability, which were outside the scope of this investigation, which greatly affected the accuracy of the beam positioning.