Research and Development on the High-Power Plasma-Assisted W-Band Backward-Wave Oscillator

We present the results of simulation and development of the W-band backward-wave oscillator (BWO) driven by a high-current sheet electron beam provided by a pseudo-spark (PS) discharge electron source. The high-frequency interaction structure based on the staggered dual grating slow-wave structure (SDG SWS) is designed and simulated using CST Studio Suite. A 3-D particle-in-cell (PIC) modeling of the W-band BWO has been carried out; the simulation was performed taking into account the processes of plasma impact ionization and ion channel formation. The PS-based hollow-cathode sheet-beam source is developed and experimentally tested. Fabrication issues of the SWS by using computer-numerical-control (CNC) nano-machining are discussed. The interaction structure is fabricated and assembled.