MSc Thesis Defence: Topics in PIXE Analysis

MSc Candidate

Peter Martin

Abstract

Proton induced x-ray emission spectroscopy (PIXE) sees widespread use in a variety of materials analysis applications. With the goal of improving the accuracy of PIXE results several projects are undertaken. In this work changes to beam visualization and beam-size calibration are described. An examination of various theoretical cross-section databases is performed, and it is shown that extending the currently used ECPSSR theory through united-atom and intra-shell corrections is unlikely to offer an improvement to PIXE results. It is also shown that the diminishing energy of protons in thick samples is unlikely to be the cause of aberrant results previously seen for certain elements. A detailed examination of pure-element thick and thin samples suggests that cross-section databases for studied elements are in line with experimental results. Finally, data from Ito et. al. and Kavcic et. al. are used to successfully improve the shape of the K-beta x-ray line of iron. This improves the regional chi-squared error value of an experimental spectrum by a significant amount, representing a more accurate fit. The methodology and data used is expected to produce similar improvements for other K-beta transition elements.

Examination Committee

• Dr. Eric Poisson, Chair
• Dr: Iain Campbell, Advisor
• Dr. Joanne O'Meara, Co-Advisor
• Dr. De-Tong Jiang, Graduate Faculty