Destructive channeling of ions in carbon nanotubes (CNT): :: SPE RESST

Destructive channeling of ions in carbon nanotubes (CNT): molecular dynamics computer experiment


The profiles of radiation damage of CNT superstructures by ions of keV energies have been built for the first time.

Directional dependences of the production rates of point defects of the graphene-like wall of CNT and energy spectra of displaced atoms (PKA) were found.

The results have been explained in terms of the theory of destructive channeling (DCH) in crystals and the theory of metachanneling (MCH).

	The threshold nature of the effect is well described by the DCH critical angle ψ_D (see Fig. 1).

Fig. 1

	Peculiarities of the PKA spectra are associated with the coherent production of defects by ions.

	The "tails" of the damage profiles are formed by meta-channeled ions (see Fig. 2)

Fig. 2

Computer experiments were carried out by means of the in-house developed code MICKSER [7(2007)] which offers an efficient molecular-dynamical (MD) simulation within a concept of the Recoil Interaction Approximation (RIA) for amorphous, single- and polycrystalline targets and nanostructures. Unlike existing analogues, such as SRIM(TRIM) and MARLOWE, the developed code makes it possible to adequately simulate collision cascades using the method of restricted molecular dynamics. This allows to perform studies of radiation damage processes.

The carried out researches are the basic ones for construction of the theory of directional effects in nanosystems, and undoubtedly will find practical application in radiation nanophysics.