Spatial Profile and Beam Composition Measurements of the University of Wisconsin Inertial Electrostatic Confinement Laboratory Ion Guns

A custom designed and manufactured set of ion guns has been in use at the University of Wisconsin Inertial Electrostatic Confinement Laboratory for both beam fusion experiments and materials implantation experiments. For the first time, direct measurements have been made on the spatial profiles and the mass compositions of He and D ion beams produced by these guns. The results validate assumptions about the circular Gaussian spatial profiles for both He and D ion beams. Mass composition measurements of the He beam identified a pressure-dependent minimum impurity content of 15% N⁺. The D beam contained relative molecular ion fractions of 58% D₃⁺, 32% D₂⁺, and 10% D⁺ with impurities of 15% to 20% D₂O⁺. A new experimental platform, the Ion Beam and Source Analyzer was developed to perform these experiments on the ion guns used to irradiate candidate fusion materials.