Electron drift in a linear magnetic wiggler with an axial guide field

Abstract
Electron trajectories through a linear magnetic wiggler in an axial guide field are calculated numerically. Off-axis electrons are shown to drift in a direction perpendicular to the wiggler field because of the wiggler gradient. Effects of self-fields and initial conditions are analyzed, and the results compared to those obtained with a helical wiggler. An empirical analytic expression for the linear wiggler drift is presented, and means of stabilizing the drift are discussed.