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 less likely than for plane wave
projectiles, and for the special case of aligned collisions, the angular momentum
of the incident electron is transferred directly to the ionized electron.