Electron Skirts and X-ray Correction: Evaluating Methods for Rapid Discrimination of Primary versus Secondary X-ray Signals in the ESEM

Abstract

The increasing popularity of ESEM, VP-SEM, and LV-SEM instruments has raised interest in ways to differentiate or unmix these two X-ray signals generated in these instruments. Under conditions of high gas pressure or long gas path length, a significant fraction of the electrons that make up the primary beam are scattered after colliding with gas molecules as the beam passes through the higherpressure region above the sample. These electrons form a broad, flat skirt that surrounds the primary beam [1, 2]. Previous experiments have documented the shape of the skirt and its effect on the X-ray resolution [3, 4].