Scattering in the variable pressure scanning electron microscope (VPSEM) affects image resolution and the ability to perform quantitative chemical measurements. However, the manner in which the total scattering cross section varies as a function of gas type and accelerating voltage is not well understood. A dual Faraday cup is constructed to measure the scattered fraction of the primary beam as a function of gas type, gas pressure, working distance, and accelerating voltage. While measured values of the total scattering cross section agree with previous work, the values calculated from theory disagree with the measured by a factor of 2. Further work needs to be done to improve the accuracy of the calculated values, which will be useful for the VPSEM community.
Citation: Microscopy and Microanalysis
Pub Type: Journals
total scattering cross section, beam gas path length, electron scattering, environmental scanning electron microscope, ESEM, Faraday cup, VPSEM