Making microbeams and nanobeams by channeling in microstructures and nanostructures

A particle beam of very small cross section is useful in many accelerator applications including biological and medical ones. We show the capability of the channeling technique using a micron-sized structure on a surface of a single crystal, or using a nanotube, to produce a beam of a cross section down to one square micrometer (or nanometer). The channeled beam can be deflected and thus well separated in angle and space from the primary and scattered particles. Monte Carlo simulation is done to evaluate the characteristics of a channeled microbeam. Emittances down to 0.001 nm rad, and flux up to ${10}^{6}\text{ }\ensuremath{\mu}{\mathrm{m}}^{\mathrm{2}}$ per second, can be achieved for protons and ions.