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

Abstract

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.

Keywords:

• Beam profile
• ion gun
• deuterium
• helium, impurities

Acknowledgments

Research in this work by M. J. Jasica was performed at the University of Wisconsin-Madison. This work has been funded in part by the University of Wisconsin-Madison, the Grainger Foundation, the Greatbatch Foundation, and TAE Technologies. Special thanks go to Richard Bonomo and Aaron Fancher for their collaboration in developing the high-voltage aspects of the IBSA.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the U.S. Government.