Ion Source Development and Characterization

Beams of deuterium and or tritium ions, which impact a target doped with the same, can produce penetrating neutrons for active interrogation. Generation of these ion beams can be achieved through methods including field ion desorption and surface flashover. Field ion desorption structures, which are conductive structures with radii of curvature on the order of nanometers, can be individually made as well as manufactured in patterned and unpatterned arrays of structures. When a high voltage is applied to the structures a strong electric field develops at the high curvature points. If a gas such as deuterium or tritium is present, either by surface adsorption or random gas phase motion, ions can be created. Surface flashover occurs when the electric potential between two conductive surfaces becomes large enough to induce a discharge along the surface of a dielectric separating them. Ions can be extracted from this discharge. Studies are being performed at the University of Missouri to confirm the ability of field ion desorption and surface flashover to produce ions, as well as to characterize the capabilities of these ion sources. To make the sources as compact as possible, research to determine the capabilities of piezoelectric transformers as voltage sources for subsequent extraction and acceleration is being conducted. Results of computational and experimental procedures will be presented.