I have this pretty old compact fluorescent (CFL) bulb from several years ago still going strong. There was a period where the bulb sat unused when I moved away from home and put the lamp in storage. I'm using it again now and noticed that at the bends in the glass the phosphor has differentially eroded with respect to curvature. What's the physical mechanism that could account for this? In terms of fluid dynamics there would be a higher turbulence at those points. Can plasma behave like a fluid and erode things?
Also where did the material go? You often see blackened/charred looking bases of CFLs, is that all eroded phosphor coating?
