Channeling star effect with bundles of carbon nanotubes

We report here about occurrence of the channeling star effect in the transmission of high energy protons through the bundles of (10. 10) single-wall carbon nanotubes, when the beam divergence is larger then the critical angle for channeling. The proton energy is 1 GeV, the beam divergence is six times the critical angle for channeling, and the bundle length is varied between 2.2 and 14.3 mu m, corresponding to the reduced bundle lengths associated with the transverse proton motion close to the centers of the regions in between three neighboring nanotubes between 0.15 and 1.00. respectively. The angular distribution of channeled protons is generated using a realistic computer simulation code. The sensitivity of the channeling star effect to the mutual orientation of the neighboring nanotubes within the bundle is analyzed, and its use for determination of this orientation is proposed. (c) 2006 Elsevier B.V. All rights reserved