Development of an External Beam Ion Milliprobe

Abstract

The goals of this Trident Project were the design, construction, testing, and initial application of an external beam ion milliprobe at the U.S. Naval Academy. The ion milliprobe is a tool for elemental analysis that employs the 1.7 million volt tandem electrostatic accelerator in Michelson C-7 to provide a beam of charged particles. The mechanism used for the analysis of elemental concentration is particle induced x-ray emission (PIXE). This technique involves detecting and counting the xrays produced when the focused beam of charged particles strikes the sample to be analyzed. This paper describes the design and construction of several essential specialized devices including an electrostatic quadrupole triplet lens, a current measuring collimator, an exit tip, and a sample enclosure. It discusses the procedures necessary to align, focus, and determine the size of the beam. Finally, the results of the initial analysis are evaluated and presented. N Table of Contents Abstract, 1 Acknowledgments, 2 List of Figures, 4 1. Introduction: Building a Tool for Elemental Analysis, 5