Electron energy-loss spectrum of nanowires

The electronic properties of nanoscale-size fibers can be studied by electron energy-loss spectroscopy with electron beams that pass near the fiber but do not penetrate it. We derive the formulas for the differential energy spectrum assuming that the fiber can be treated as a dielectric cylinder. The formula can be evaluated in closed form for a conducting wire; the spectrum displays the surface plasmon and a low-energy peak associated with charge-conduction modes that diverges inversely as the energy loss.