  We investigate the excitation of electrostatic wakefields in metallic
nanostructures (nanowires) due to the propagation of a short electron pulse.
For that purpose, a dispersive (nonlocal) dielectric response of the system is
considered, accounting for both the finiteness of the system and the quantum
(Bohm) difraction of the conduction electron band, generalizing the results
obtained previously in the literature [Phys. Rev. Lett. \textbf{103}, 097403
(2009)]. We discuss on the stability conditions of wakefields and show that the
underling mechanism can be useful to investigate new sources of radiation in
the extreme-ultra-violet (XUV) range.
