Detection and characterization of contamination with fluorescence spectroscopy

Abstract

In the field of failure analysis and in particular molecular and particulate contamination, being able to detect any trace of contaminants during the integration of an orbital spacecraft is crucial. In this context, fluorescence allows not only to detect but also to discriminate contaminants. We studied the fluorescence response of two epoxy adhesives, typical sources of spacecraft contamination in orbit with a portable broadband hyperspectral instrument (UV-Vis-NIR) developed in collaboration with the CNES and Intraspec Technologies, but also with a commercial spectrofluorometer. These measurements had two objectives, evaluate the performance of our hyperspectral instrument in order to identify prospect of improvement, but as well study the pertinence of fluorescence signature study in the contamination field. The first goal brings out that the hyperspectral instrument is capable of imaging the scene and allows us to extract fluorescence spectra from the image, but it still needs development, especially in term of sensitivity in UV range. The second goal shows promising results. Fluorescence studies with the spectrofluorometer emphasize that fluorescence spectra are specific to the chemical nature of the contaminant, which allows us to clearly discriminate them.