Location of Shoulders in Channeling Phenomena

A Monte Carlo computer program for use in calculating channeling effects has been written. It incorporates a model of lattice vibrations in which the lattice atoms vibrate independently of each other. The position of the shoulder for a planar channel is predicted quite well by the breakthrough angle for trajectories in the channel. The position of the shoulder of a row channel is found to be determined by the shoulders of the several planar channels intersecting at the row channel. The breakthrough angle for rows appears to mark a rather sharp boundary between orientations in which row or planar effects predominate.