Guiding of electron beams by hollow conducting channels

The use of hollow conducting channels to guide relativistic electron beams through dense gases is explored theoretically. The channel conditions needed to effect strong guidance are determined from analytic and numerical computations of the transverse force felt by a beam uniformly displaced but propagating inside the channel. The force is shown to be strong in the beam head but weak in the beam body. Several different channel configurations are considered, and various effects that can degrade channel guidance are discussed.