A proton beam guidance apparatus and a method of providing proton beams having sub-micron beam width and MeV energies. The apparatus is a structure having an enclosed channel that can reflect or guide protons by grazing incidence interactions. The enclosed channel is in some embodiments an annular channel. The enclosed channel is shaped to provide a helical path for each proton in the beam. Protons are provided to an input port of the channel, and after multiple grazing incidence interactions with the walls of the channel, are provided as an output beam having dimensions comparable to the cross sectional dimensions of the channel. The channels can have cross sectional dimensions of tens of nanometers or less. No externally applied electromagnetic fields are needed to guide the proton beam. Contemplated applications include use of the exit proton beams to provide medical treatment to patients.