Interface Between a Gatan PEELS and an EDAX 9900 Computer for Simultaneous Energy Loss Analysis and Chemical Mapping

Introduction Energy loss spectroscopy is a well known technique allowing elemental analysis in thin films. When an energy loss spectrometer is coupled with a STEM it is possible in addition to perform chemical mapping. The U314 INSERM laboratory is equipped with a C.M. 30 PHILIPS STEM coupled with an EDAX 9900 and a GATAN 666 parallel detection electron spectrometer. We describe a complete system including an additional A.T. microcomputer enabling simultaneous energy loss analysis and chemical mapping . Material and method An interface fitted with the bus connecting the GATAN electronics and the EDAX multichannel analyzer (MCA) allows to read the data during a photodiode read-out, and to send them via a parallel port into the host A.T microcomputer. To do this, only 18 bus lines are used and the proprietary communication protocol between the photodiode interface and the MCA is not affected. All the functions provided by the EDAX PVEELP software are preserved.