|Department:||Department of Physics.|
|Full text PDF:||http://digitool.library.mcgill.ca/thesisfile122619.pdf|
The original theory of J.R. Pierce and A.V. Haeff pertaining to the problem of the existence of waves within a narrow beam of electrons of two different average velocities, is discussed. The theory is then extended to the case of wide beams separated by a finite distance. A special case of this theory is then considered, that of a wide pencil of two superimposed streams and the variation of signal amplification that may occur under suitable conditions is studied, as a function of beam width. The results indicate considerable discrepancies between the two theories in cases of narrow beams. As the width increases, however, the two cases tend asymptotically to a common value.