High perveance TWT modeling and experimental verification

The modeling and design of high perveance TWTs present significant challenges when one considers the role that space charge plays in all aspects of gun design, beam propagation and focus, RF interaction, and beam recollection. Some applications require the use of low voltage, high current electron beams which in turn require special analysis and design techniques not always required by lower perveance devices. This work shows that accurate RF simulation of high perveance TWTs, even in a highly scalloping configuration, can be accomplished through the combined use of several modem TWT design tools. Studies of efficient recollection of the high-space-charge spent beam and evaluation of backward wave and diocotron instabilities is ongoing and will be important in the overall evaluation of this TWT design. RF modeling results and a full set of experimental data are presented.