Radiation of non-relativistic particle on a conducting sphere and a string of spheres

The radiation arising under uniform motion of non-relativistic charged particle by (or through) perfectly conducting sphere is considered. The rigorous results are obtained using the method of images known from electrostatics.
Presented on the conference "Channeling-2016", Sirmione - Desenzano del Garda, Italy, September 25 - 30, 2016 v2: Figure 5 corrected, Journal reference added