Channeling of Protons Through Carbon Nanotubes Embedded in Dielectric Media

TL;DR

This study explores how dynamic polarization influences proton channeling in carbon nanotubes embedded in dielectric media, revealing effects on proton distributions that could impact nanoscale ion beam applications.

Contribution

It demonstrates the significant impact of dynamic polarization on proton distributions in nanotubes, considering various media and proton energies, which was not previously detailed.

Findings

Dynamic polarization alters rainbow maxima in proton distributions.

Proton flux increases near nanotube walls due to polarization effects.

Potential applications in nanoscale ion beam technologies and atom detection.

Abstract

We investigate how the dynamic polarization of the carbon atoms valence electrons affects the spatial distributions of protons channeled in the (11, 9) single-wall carbon nanotubes placed in vacuum and embedded in various dielectric media. The initial proton speed is varied between 3 and 8 a.u., corresponding to the energies between 0.223 and 1.59 MeV, respectively, while the nanotube length is varied between 0.1 and 0.8 $\mu$m. The spatial distributions of channeled protons are generated using a computer simulation method, which includes the numerical solving of the proton equations of motion in the transverse plane. We show that the dynamic polarization effect can strongly affect the rainbow maxima in the spatial distributions, so as to increase the proton flux at the distances from the nanotube wall of the order of a few tenths of a nanometer at the expense of the flux at the nanotube center. While our findings are connected to the possible applications of nanosized ion beams created with the nanotubes embedded in various dielectric media for biomedical research and in materials modification, they also open the prospects of applying ion channeling for detecting and locating the atoms and molecules intercalated inside the nanotubes.