Excitation of Plasmonic Wakefields in Multi-Walled Carbon Nanotubes: A Hydrodynamic Approach

Abstract

The interactions of charged particles with carbon nanotubes (CNTs) may excite plasmonic modes in the electron gas produced in the cylindrical graphene shells that constitute the carbon nanotube walls. These excitations have recently been proposed as a potential novel method of short-wavelength-high-gradient particle acceleration that may revolutionize particle acceleration techniques. In this chapter, we review a theory based on a linearized hydrodynamic model to describe the electronic excitations on the nanotube walls produced by a point-like charge moving paraxially through multi-walled CNTs. In this model, the plasmonic excitations on the nanotube surfaces are described considering the electron gas as two-dimensional plasma with additional contributions to the fluid momentum equation from specific solid-state properties of the gas. Analytical expressions of the excited longitudinal and transverse wakefields are derived. These general expressions are particularized for the case of single- and double-walled nanotubes, relating them with the resonant frequencies obtained from the dispersion relation. The dependence of the wakefields on the parameters of the model such as the particle velocity, the nanotube radii and the surface density is analyzed. Finally, a comprehensive discussion is presented, addressing the feasibility and potential limitations of employing the linearized hydrodynamic theory for modelling CNT-based particle acceleration.