Class
Article
College
College of Science
Department
Physics Department
Faculty Mentor
JR Dennison
Presentation Type
Poster Presentation
Abstract
The effects of imposing surface roughness on the electron yield (EY) of highly polished aluminum (Al) and copper (Cu) samples were studied. Measured characteristics such as surface roughness, composition, contamination, oxidation, and charging are known to significantly affect EY, though quantitative models are not well established. Surface roughness is generally thought to cause the EY to decrease as the surface roughness increases for most incident electron energy levels by increasing the surface area for emitted secondary electrons to collide with the material, although recent studies have shown the interactions may be more complicated. Surface roughness for this study was characterized by the grit of the polishing compound used, ranging from 0.3 to 10 µm, on optically smooth samples. Scanning electron and confocal microscopy delivered the physical width of the grooves. The EY – the ratio of emitted electrons per incident electron – was measured by bombarding samples with incident electrons ranging from 20 eV to 30 keV. Investigating the common, elemental, conducting, and well-studied materials Al and Cu, better isolates the changes induced by various levels of controlled, well-characterized roughening. The results are compared with simple models of EY resulting from surface features with various depth, aspect ratio, density, and shape as well as with similar well-established models of surface roughness effects on analogous optical reflectivity. Presentation Time: Wednesday, 2-3 p.m. Zoom link: https://usu-edu.zoom.us/j/87892002075?pwd=Ym1Tcy9NOVhaaGZWczZWY1JCL3owUT09
Location
Logan, UT
Start Date
4-11-2021 12:00 AM
Included in
Effects of Surface Roughening on Electron Yields of Polished Cu and Al Samples
Logan, UT
The effects of imposing surface roughness on the electron yield (EY) of highly polished aluminum (Al) and copper (Cu) samples were studied. Measured characteristics such as surface roughness, composition, contamination, oxidation, and charging are known to significantly affect EY, though quantitative models are not well established. Surface roughness is generally thought to cause the EY to decrease as the surface roughness increases for most incident electron energy levels by increasing the surface area for emitted secondary electrons to collide with the material, although recent studies have shown the interactions may be more complicated. Surface roughness for this study was characterized by the grit of the polishing compound used, ranging from 0.3 to 10 µm, on optically smooth samples. Scanning electron and confocal microscopy delivered the physical width of the grooves. The EY – the ratio of emitted electrons per incident electron – was measured by bombarding samples with incident electrons ranging from 20 eV to 30 keV. Investigating the common, elemental, conducting, and well-studied materials Al and Cu, better isolates the changes induced by various levels of controlled, well-characterized roughening. The results are compared with simple models of EY resulting from surface features with various depth, aspect ratio, density, and shape as well as with similar well-established models of surface roughness effects on analogous optical reflectivity. Presentation Time: Wednesday, 2-3 p.m. Zoom link: https://usu-edu.zoom.us/j/87892002075?pwd=Ym1Tcy9NOVhaaGZWczZWY1JCL3owUT09