Propagation of Intense Electron Beams Through a Rectangular Tube

In this study, cylindrical intense electron beams were injected into a rectangular tube. The beam cross section profiles were observed along the propagation path. The single-beam profile was deformed periodically. The center of the beam cross section was shifted when the beam was not injected just on the tube center. When two beams were injected, the beams rotated each other, and the distance between them decreased. Using a simple model with momentum equations of the line density elements for the beam, it was evident that E\times B drift, which originated from the asymmetric electric field and the magnetic field on the beam, caused the previously mentioned phenomena.