Multiple ionization X-ray satellites of magnesium, aluminum and silicon in alpha particle PIXE

Wavelength-dispersive spectroscopy was used to study the multiple ionization satellites in the K X-ray spectra of magnesium, aluminum and silicon bombarded by alpha particles having energies of 3, 4 and 5 MeV. The measured energy shifts and intensities relative to the diagram lines of the groups with one, two and three L-shell vacancies were extracted from the spectra. These results compare well with the values in an interim database which was recently assembled from the limited existing literature. The present work is the first step in refining this database so that it may be used to improve the accuracy of PIXE analysis using alpha particle beams, including the PIXE mode of the Mars alpha particle X-ray spectrometers. The effects of oxide bonding are also determined and compared to those observed when excitation is effected by photons and by electrons.