A 94 GHz overmoded coupled cavity TWT experiment

Abstract

A 94 GHz overmoded coupled-cavity Traveling Wave Tube (TWT) has been designed with 30 dB of gain and 300 W peak power output. An experiment is being fabricated to test the overmoded TWT. The device operates in the TM31 mode with minimal losses, and a lossy AlN dielectric loading is selectively placed in the structure to suppress unwanted modes in the cavities. A cold test of the overmoded coupled-cavities was machined in Glidcop and agrees well with simulation. The TWT experiment is currently under operation, with a 2.5 kG solenoid magnet, 2 microsecond pulse modulator, and in-house designed 30 kV Pierce electron gun. An initial beam test of the 30kV, 320 mA Pierce electron gun shows good agreement with Michelle simulations, and further results are forthcoming.