UC Berkeley

The use of accelerator-based neutron generators for non-destructive imaging and analysis in commercial and security applications is continuously under development, with improvements to available systems and combinations of available techniques revealing new capabilities for real-time elemental and isotopic analysis. The recent application of associated particle imaging (API) techniques for time- and directionally-tagged neutrons to induced fission and transmission imaging methods demonstrates such capabilities in the characterization of fissile material configurations and greatly benefits from improvements to existing neutron generator systems. Increased neutron yields and improved spatial resolution can enhance the capabilities of imaging methods utilizing the API technique. The work presented in this dissertation focused on the development of components for use within an API neutron generator with enhanced system spatial resolution. The major focus areas were the ion source development for plasma generation, and passive ion beam focusing techniques for the small ion beam widths necessary for the enhanced spatial resolution. The ion source development focused on exploring methods for improvement of Penning-type ion sources that are used in conventional API neutron generator systems, while the passive beam focusing techniques explored both ion beam collimation and ion guiding with tapered dielectric capillaries for reduced beam widths at the neutron production target.