GIXRF/XRR Data Analysis based on Differential Evolution Algorithm

N. VAKULA; JUAN JOSÉ LEANI; A. MIGLIORI; M. BOGOVAC; R. PADILLA-ALVAREZ; R. KAISER; A. KARYDAS

Bologna

Congreso; GIXRF/XRR Data Analysis based on Differential Evolution Algorithm; 2014

Alma Mater Studiorum University of Bologna

The Grazing Incidence XRF analysis utilizes a low divergence exciting X-ray beam to provide depth sensitive information with nanometer resolution based on the features of the X-ray Standing Wave (XSW). An X-ray tube coupled with a multilayer monochromator can achieve the minimum required divergence for the incident radiation (~0.03 degrees), whereas the use of an additional slit in front of the sample can improve further the angular resolution [1- 3]. In the present work a GIXRF/XRR spectrometer based on an air-cooled Mo anode x-ray tube (50 kV, 0.8 mA) is presented. It utilizes an X-ray mirror consisted of two 100 mm asymmetric cut Mo/Si multilayers placed aside, thus optimizing primary beam divergence and energy resolution and delivering a 2-dimensional parallel Mo-Kα exciting beam (ASTIX-c mirror by AXO, Dresden).The X-ray tube and optics assembly have been coupled with an Ultra High Vacuum Chamber (UHVC) facility, based on a prototype designed by PTB and TUB [4]. The UHVC is endowed with a motorized 5-axis sample manipulator and a 2-axis detectors movement with respect to the sample position allowing Grazing Incidence / Exit X-Ray Fluorescence and X-Ray Reflectometry (XRR) measurements. The chamber is equipped with an ultra-thin window Silicon Drift Detector (30 mm2,