IBIXFIT: A Tool For The Analysis Of Microcalorimeter PIXE Spectra

PIXE analysis software has been for long mainly tuned to the needs of Si(Li) detector based spectra analysis and quantification methods based on K alpha or L alpha X-ray lines. Still, recent evidences related to the study of relative line intensities and new developments in detection equipment, namely the emergence of commercial microcalorimeter based X-ray detectors, have brought up the possibility that in the near future PIXE will become more than just major lines quantification. A main issue that became evident as a consequence of this was the need to be able to fit PIXE spectra without prior knowledge of relative line intensities. Considering new developments it may be necessary to generalize PIXE to a wider notion of ion beam induced X-ray (IBIX) emission, to include the quantification of processes such as Radiative Auger Emission. In order to answer to this need, the IBIXFIT code was created based much on the Bayesian Inference and Simulated Annealing routines implemented in the Datafurnace code [1]. In this presentation, the IBIXFIT is used to fit a microcalorimeter spectrum of a BaxSr(1-x)TiO3 thin film sample and the specific possibility of selecting between fixed and free line ratios combined with other specificities of the IBIXFIT algorithm are shown to be essential to overcome the problems faced.