  Optical vortex beams have an extensive history in terms of both theory and
experiment, but only recently have electron vortex beams been proposed and
realized. The possible applications of these matter vortex waves are numerous,
but a fundamental understanding of their interactions with atoms and molecules
has not yet been developed. In this work, fully differential cross sections for
fast (e,2e) collisions using electron vortex projectiles with small amounts of
quantized orbital angular momentum are presented. A comparison is made with the
fully differential cross sections using plane wave projectiles and a detailed
study of angular momentum transfer is included. Results indicate that
ionization by electron vortex beam projectiles is much less likely than for
plane wave projectiles, and the angular momentum of the incident electron is
transferred directly to the ionized electron.
