GeoPIXE

GeoPIXE™ is a processing software package for proton induced X-ray emission (PIXE), synchrotron and now Maia Mapper XRF analysis. GeoPIXE™ incorporates the Dynamic Analysis method for real-time PIXE/SXRF spectral deconvolution to project quantitative PIXE/SXRF elemental images from list-mode data, and tools for image exploration in multi-element space, spectra extraction for quality control, and for multi-layered targets, using an efficient Windows/Linux graphical user interface.

X-ray spectra are made up of Gaussian peaks superimposed on a background. The area under each peak is proportional to the concentration of the element in the material being analysed. Overlaps between peaks cause difficulties in analysing for elements with low concentrations because small peaks of low concentration elements are swamped by peaks of more abundant elements. Assuming each spectrum is a linear combination of its component elemental signatures gives a set of linear simultaneous equations that can be solved for elemental concentration. Dynamic Analysis works by using a fast matrix-approach to solving these equations relating intensity in each channel of the spectrum to the elemental concentrations.

The original Dynamic Analysis approach assumes a constant composition and density of matrix material across the sample. Geological samples, and especially ore materials, are highly heterogeneous and so this approximation was not satisfactory for many applications. A two-pass Dynamic Analysis method extends Dynamic Analysis to samples containing phases with widely varying densities and compositions so that the composition of each phase can be measured with similar precision.

More information is available on GeoPIXE here