Channeling as a method of making nanosized beams of particles
  Particle channeling in a bent crystal lattice has led to an efficient instrument for beam steering at accelerators, demonstrated from MeV to TeV energies. In particular, crystal focusing of high energy protons to micron size has been demonstrated at IHEP with the results well in match with Lindhard (critical angle) prediction. Channeling in crystal microstructures has been proposed as a unique source of a microbeam of high-energy particles. Channeling in nanostructures (single-wall and multi-wall nanotubes) offers the opportunities to produce ion beams on nanoscale. Particles channeled in a nanotube (with typical diameter of about 1 nanometer) are trapped in two dimensions and can be steered (deflected, focused) with the efficiency similar to that of crystal channeling or better. This technique has been a subject of computer simulations, with experimental efforts under way in several high energy labs, including IHEP. We present the theoretical outlook for making channeling-based nanoscale ion beams and report the experience with crystal-focused microscale proton beams. 
V.M. Biryukov