Universitat Politècnica de Catalunya. Remote Sensing, Antennas, Microwaves and Superconductivity Group (CommSensLab)
Abstract
Charged particles moving through a carbon nanotube may be used to excite electromagnetic
modes in the electron gas produced by π and σ orbitals in the cylindrical graphene shell that
makes up a nanotube wall [1]. This effect has recently been proposed as a potential novel
method of short-wavelength-high-gradient particle acceleration [2, 3]. In this contribution, first
we review the existing theory based on a linearised hydrodynamic model for a non-relativistic,
localised point-charge propagating in a single wall nanotube (SWNT) [4]. Then we extend it to
the relativistic case. In this hydrodynamic model the electron gas is treated as a plasma with
additional contributions to the fluid momentum equation from specific solid- state properties
of the gas. The governing set of differential equations is formed by the continuity and
momentum equations for the involved species: beam charges, electrons and ions of the lattice.
These equations are then coupled by Maxwell’s equations. The ions are assumed to be quasistatic
and provide a neutralising background. To solve the differential equation system a
modified Fourier-Bessel transform has been applied. Furthermore, a spectral analysis has been
realised to determine the plasma modes able to excite a longitudinal electrical wakefield
component in the SWNT to accelerate test charges. Eventually, we discuss the suitability and
possible limitations of the method proposed in this study for particle acceleration
