Contribution à l’étude du rôle amplificateur du gaz dans un MEB environnemental

Abstract

The objective of this work was the description of the secondary electron-gas interaction in the analysis chamber of an environmental scanning electron microscope (ESEM). The study focuses on the use of Helium-carbon dioxide, and Helium-Argon mixtures, which have been proposed to test the possibility of increasing amplification when the secondary electron detector (GSED)is used. By way of comparison, we have also introduced a study on the amplification of other mixtures as well as water vapor. This gas is of almost unavoidable utility in the MEBE, for biological observations and for the observation of insulating samples. We have also added the characteristics of helium as a monatomic reference gas widely studied previously in our laboratory. In terms of amplification, the 5% CO2 mixture is the most suitable to ensure better ionization than pure helium, while keeping a skirt within limits Reasonable.