US Patent 8159157 - Nano-gun

http://www.freepatentsonline.com/8159157.html

The claims from this patent from Raytheon appear to be reciting the world's smallest gun using a nanotube to eject atomic bullets so as to generate particle beams. Claim 1 reads:

1. A linear accelerator comprising:

a substrate comprising a plurality of nanotubes and one or more other constituent materials, the plurality of nanotubes comprising 1 to 5 percent of the substrate;

a particle disposed within a nanotube of the plurality of nanotubes, the nanotube having a cylindrical shape; and

an energy source configured to apply energy to the nanotube to cause the particle to accelerate.