SPECTRUM ANALYSIS TAKING ACCOUNT OF THE TAIL, ESCAPE FUNCTIONS AND SUB-LINES (SAPIX version 4)

Abstract

A new x-ray-spectrum-analysis program, which is capable of fitting with response functions including a tail function, an escape peak and sub-lines, has been developed. In this code, the tail function is expressed by combination of two or three Gaussian functions. A tail function, an escape and sub- or satellite-lines are regarded as functions belonging to the main peak and are included in it. A small shift of peak position depending on measuring conditions can be easily corrected in the program. As a result of fitting to practical spectra with the response function thus prepared, it becomes possible to draw a smooth background over a wide x-ray-energy range and to analyze a whole spectrum simultaneously. Thus, accuracy and reproducibility of a spectrum analysis are much improved. By means of this code, correct values of peak yield of Co - K α, which overlaps with the tail of Fe - K β and is quite difficult to be accurately separated by fitting with Gaussians, have been obtained. Furthermore, accuracy of peak separation of a small peak, which overlaps with the escape peak belonging to a huge peak, has been improved. Accuracy of quantitative analysis for high-Z elements by means of Kβ yields has also been improved by using the response function including sub-lines, and it became possible to accurately separate small Kα lines from Kβ lines of the other elements.