High power mini-TWT development at L-3 Communications

Summary form only given. This paper provides a hardware-centered status on the progress over the last year in extending wideband mini-TWT performance to 200 W. Over the least year, L-3 has completed two designs demonstrating 200 to 400 W CW over more than an octave, with peak efficiencies of nearly 50% using only a three-stage collector. The mini-TWT gun assembly shares common parts with production TWTs while only requiring a new cathode and beam-forming electrode. The cathode current density is less than 2 A/cm/sup 2/, which results in exceptionally long life. The higher beam perveance of the mini-TWT design allows for wide band operation with good power flatness. This talk presents experimental data and challenges overcome on recent high power designs.