Elemental Composition Analyses in Thick Atmosphere Using the Atmospheric Electron-induced X-ray Spectrometer (aexs) Instrument,

Introduction: This paper describes the progress in the development and application of the AEXS instrument to determine elemental abundance by analysis of the excired XRF spectra. The AEXS is a miniature instrument based on the excitation of characteristic X-Ray Fluorescence (XRF) spectra from samples in ambient atmosphere using a focused electron beam. Operation in ambient atmospheres with moderate-tohigh spatial resolution in comparison to similar instruments is obtained through the use of a thin electron transmissive membrane to isolate the vacuum of the AEXS electron probe from the outside atmosphere. The isolation obviates the need for the samples to be drawn into a vacuum pumped sample chamber as is common in all laboratory SEM’s. Samples are evaluated in their pristine state with no surface preparation. The transmitted electrons through the membrabe and atmosphere impinge on the external samples exciting XRF spectra from the irradiated spots with sub-mm to cm-scale spatial resolution at Mars atmospheric pressure. The development of the instrument is described in detail in another poster paper at this conference. This paper focuses on describing the capability of the most recently assembled AEXS instrument to analyze the acquired XRF data using a commercially available software.