PIXE and PESA aspects of the Guelph Visibility and Fine Particulate Monitoring Program

Abstract

This paper describes the analytical equipment, data processing, and quality assurance protocol of the Visibility and Particulate Monitoring Program run by the Guelph Scanning Proton Microprobe (GSPM) laboratory at the University of Guelph. The focus of the discussion is the ion beam analyses used in the program. A new experimental chamber for Proton-Induced X-ray Emission (PIXE) and Proton Elastic Scattering Analysis (PESA) of particulate samples is presented. The chamber provides a fast and reliable analysis of thin samples by PIXE and PESA. The PIXE spectra are collected simultaneously by two Si(Li) detectors to increase sensitivity and reliability of the measurement. Several aspects of thin target PIXE calibration are discussed. An extension to the GUPIX software package for automatic analysis of aerosol samples is presented. Three levels of quality assurance are described, including analysis of fly ash particles on artificial filter, linear regression between the two PIXE detectors, intra- and interlaboratory comparisons, and calculation of the reconstructed mass (RCMA) from composite variables and its comparison to fine mass.