Channeling of protons in radially compressed chiral carbon nanotubes

Channeling of 10 MeV protons in various types of point and area radially compressed chiral carbon nanotubes (CNTs) is considered. Monte Carlo simulation program is used for the calculation of the trajectories, energy losses and angular distributions of protons in (6,4) and (11,9) CNTs of 2000 nm length, where the potential in Doyle-Turner approximation is used to describe the interaction between a proton and a nanotube. Carbon nanotubes, which are considered, are radially compressed at two points (500 nm and 1500 nm each), at a middle area of various lengths, at three points (both ends and at the centre) and at both ends with a middle area remaining uncompressed. The results show that in a specific case of compressed nanotube a decreased angular distribution of the beam is observed, compared even with propagation in a straight uncompressed nanotube. Furthermore, the energy distribution of channeled protons depends on the type of compression.