TEMPORAL EVOLUTION OF A LONG-PULSE HIGH-DENSITY ELECTRON-BEAM

The temporal evolution of a long-pulse high-density electron beam in a high-power traveling-wave tube with a periodic magnetic focusing syst em is investigated. The relation between the variation of the characte ristics of the electron beam and ionization of the residual gas and pa rticles desorbed from the electrode surfaces is shown. A strong influe nce of the formation of the collector plasma and the flux of ions from its surface on the beam dynamics is revealed. The effect of microwave fields in the transport channel on the characteristics of the beam du ring its evolution is studied. (C) 1997 American Institute of Physics.