Class
Article
College
College of Science
Department
Physics Department
Presentation Type
Poster Presentation
Abstract
This project investigates the charging properties and electron yields of highly insulating granular samples, and how these properties may differ from bulk surfaces of the same composition. Measurements were made on both smooth and granular surfaces of materials including aluminum oxide, silicon dioxide, sodium chloride, and magnesium oxide. The dramatic effects of surface roughness on electron yield values became evident after comparing the preliminary results of rougher granular samples to those of smooth bulk crystalline surface. In every case tested, the more complex surface morphology resulted in a greatly reduced maximum yield, without substantially affecting the curve shape or energy at maximum yield. Alumina dust was tested most extensively and was found to have a maximum yield of~2, 10 times smaller than its polished surface bulk crystalline counterpart, sapphire. More limited data on granular particles of NaCl, MgO, and Al2O3 (of varying particle shape and size) showed similar trends. It is postulated that the increased surface roughness, and possibly porosity, leads to increased recapture of emitted electrons, thus dampening the overall electron yield values measured.
Location
Logan, UT
Start Date
4-12-2023 11:30 AM
End Date
4-12-2023 12:30 PM
Included in
Electron Yield Analysis of Highly Insulating Granular Particles
Logan, UT
This project investigates the charging properties and electron yields of highly insulating granular samples, and how these properties may differ from bulk surfaces of the same composition. Measurements were made on both smooth and granular surfaces of materials including aluminum oxide, silicon dioxide, sodium chloride, and magnesium oxide. The dramatic effects of surface roughness on electron yield values became evident after comparing the preliminary results of rougher granular samples to those of smooth bulk crystalline surface. In every case tested, the more complex surface morphology resulted in a greatly reduced maximum yield, without substantially affecting the curve shape or energy at maximum yield. Alumina dust was tested most extensively and was found to have a maximum yield of~2, 10 times smaller than its polished surface bulk crystalline counterpart, sapphire. More limited data on granular particles of NaCl, MgO, and Al2O3 (of varying particle shape and size) showed similar trends. It is postulated that the increased surface roughness, and possibly porosity, leads to increased recapture of emitted electrons, thus dampening the overall electron yield values measured.