Magnetically insulated coaxial diode non-linear properties

Summary form only given. Recently developed method of dynamic time-domain reflectometry (DTDR, [1]) provides a picosecond time reference of the emitted electron beam with a subnanosecond voltage front applied to the accelerating gap of magnetically insulated coaxial diode (MICD) which is widely applicable in relativistic backward wave oscillators (BWOs). Our additional motivation of presented investigation is related with DTDR capabilities in determining of time-dependent rise of electron current emission. The last opportunity makes one possible to formulate physically-correct initial conditions for the unsolved task of non-stationary MICD where emissivity of the explosive electron emission (EEE) cathode is finite. Above problems are urgent to create phase-stable excitation of multi-channel microwave oscillators operating in X-band and Ka-band [2,3]. In the report we are planning to suggest information regarding the macroscopic electric field strength at the cathode emissive edge which is sufficient for transition of field emission to the EEE. This knowledge is important to provide a stable, rapid-response operation of the cathode, which is typically made of graphite. Similar data are necessary to eliminate spurious emissions at a high-potential metallic cathode holder. DTDR provides an opportunity to track changes in the cathode emission from pulse to pulse with a precision of less than 10 ps when cathode aging. Also, dynamic changes of the MICD impedance will be analyzed for the cathodes operating in various magnetic fields, and when graphite dispersiveness of such a cathodes differs from sample to sample. Finally, the particle-in-cell model of relativistic BWO will be presented, where real emissivity of the cathode will be considered.