Reproducible x-ray reflectometry optimization: statistical analysis of   differential evolution fitting of multilayer structural models
  We test the reproducibility of X-ray reflectometry(XRR) measurements and optimizations using an National Metrology Institute of Japan (NMIJ)/National Institute of Advanced Industrial Science and Technology (AIST) pre-standard. Based on bootstrap analysis of repeated refinements, using several CPU-years of time, we provide concrete recommendations of best practices for ensuring the reproducibility of XRR model fitting results. These recommendations can be used to study both instrument repeatability and cross-instrument reproducibility. Because the recommendations used optimizations methods available in commonly used commercial software, they can quickly be applied both in research and analytical laboratories, as well as fabrication environments. 
Donald Windover, David Gil, Yasushi Azuma, Toshiyuki Fujimoto
cond-mat.mtrl-sci physics.ins-det