Quantum-mechanical collimation and diffraction of electron beams in magnetic fields

Behavior of an electron beam injected from a waveguide into an open space in magnetic fields is studied by the method analogous to that Kirchhoff applied to the diffraction of light. It is found that magnetic field quantum-mechanically collimates electron beams. An electron beam injected from an orifice travels longer distance than that classical theory predicts before reflection on the boundary. Substructure of electron beams around the reflection point is interpreted by introducing the effect of magnetic fields to the diffraction theory in the absence of a magnetic field. (author)