Can a Single-Wall Carbon Nanotube be an X-Ray Waveguide?

We study the transport efficiency for x-rays of single-wall carbon nanotubes (SWCNTs) in theory. Three effects, i.e. refraction, absorption and x-ray tunnelling loss, are considered. Our calculation shows that the SWCNT cannot be an x-ray waveguide due to the large x-ray tunnelling loss. If the tunnelling loss can be reduced effectively, a nanotube could be a waveguide.