The program packages ATHENA [ 19 ] , ARTEMIS [ 19 ] , IFEFFIT [ 20 ] , FEFF [ 12,21 ] , PySpline [ 22 ] , Sixpack [ 23 ] , and PyMCA [ 24 ] were applied for the XAS data analysis . Initially careful radiation damage studies were performed by studying spectra collected at different time intervals . Only spectra that showed no signs of decomposition were further processed .