  Channeling of high-energy particles in straight and bent multi-wall nanotubes
(MWNT) has been studied in computer simulations and compared to the channeling
properties of single-wall nanotubes (SWNT) and bent crystal lattices. It is
demonstrated that MWNT can efficiently channel positively-charged high-energy
particles trapped between the walls of MWNT. Bending dechanneling in MWNT has
been computed as a function of the particle momentum to nanotube curvature
radius ratio, $pv/R$. It is found that a bent MWNT can steer a particle beam
with bending capabilities similar to those of bent silicon crystal lattice and
to those of best (i.e. the narrowest) SWNT. In view of channeling applications
at particle accelerators, MWNT appear favored as compared to SWNT, because MWNT
can be produced quite straight (and in aligned array), while SWNT is typically
very curved, thus posing a severe problem for channeling applications.
Therefore, we suggest that MWNT provide a better candidate for channeling than
SWNT.
