The Guelph PIXE software package III: Alternative proton database

A second X-ray production database is introduced into GUPIX to complement t he existing theoretical (ECPSSR-DHS) database and to provide some estimate of analytical uncertainty due to this aspect of GUPIX; it is based on publi shed compilations and analyses of large numbers of measured K and L subshel l X-ray production cross-sections. The two databases are compared through a nalysis of single-element standards and standard reference materials. Good agreement is observed for the case of K X-rays. In contrast, neither the th eoretical nor the "reference" database appears to be entirely satisfactory in the case of L X-rays. New work is required on L subshell X-ray productio n cross-sections using protons. The tools in GUPIX for film thickness deter mination are expanded, and tested using the two alternative databases. (C) 2000 Elsevier Science B.V. All rights reserved.