Abstract: Angular electrostatic filters and methods of filtering that remove energy contaminants from a ribbon shaped ion beam are disclosed. An angular electrostatic filter comprises a top deflection plate and a bottom deflection plate extending from an entrance side to an exit side of the filter. The bottom deflection plate is substantially parallel to the top deflection plate and includes an angle portion. An entrance focus electrode is positioned on the entrance side of the filter and an exit focus electrode is positioned on the exit side of the filter and both serve to focus the ion beam. Edge electrodes are positioned between the top and bottom deflection plates and at sides of the filter to mitigate edge effects. A negative bias is also applied to the top and bottom plates to mitigate space charge by elevating the beam energy.

Abstract: A linear acceleration system comprises one or more accelerating stages along an axis and a unipolar electrostatic quadruple lens in series with the one or more accelerating stages. The unipolar electrostatic quadruple lens focuses an ion beam in a direction transverse to the axis. The unipolar electrostatic quadruple lens includes a switching circuit, a first pair of electrodes, and a second pair of electrodes. The switching circuit controllably connects to ground and a first voltage potential. The electrodes of the first pair are located opposite each other and are connected to the switching circuit. The electrodes of the second pair are also located opposite each other and connected to the switching circuit. The second pair of electrodes are biased to a second voltage potential.

Abstract: The present invention mitigates loss of beam current, particularly for low energy ion beam transport. The present invention employs unipolar electrostatic quadrupole lenses instead of conventional dual positive and negative potential (bipolar) quadrupole lenses as beam focusing elements within a linear accelerator, reducing beam current losses therein. In addition, the present invention also includes systems and methods for switching between bipolar wiring and unipolar wiring.