Effects of Laser Surface Modification on Secondary Electron Emission of Copper

The effects of surface roughness on secondary electron emission (SEE) are investigated for copper. The surface of the copper samples was modified using a high-power neodymium-doped yttrium aluminum garnet laser, where the degree of surface modification depended on the duration and intensity of the laser exposure. Four different levels of modification were tested, in addition to the unmodified sample. Minor modification resulted in the biggest effect, significantly reducing the SEE. However, this effect only holds true for very low electron dose, where dose is the incident charge per unit area. For higher dose levels, those that are commensurate with "technical materials" in applied situations, there was a negligible effect of surface roughness on SEE. The data set presented here seeks to quantify the effect of surface roughness with further gradations than what is accounted for in the semiempirical formulas in the literature.