Efficiency enhanced, load-limited MILO

Summary form only given, as follows. The self-insulating property of a magnetically insulated line oscillator (MILO) obviates the need for an external circuit to supply the magnetic field, but restricts the efficiency of power production to values far below (factor of 4) what is achievable with a conventional magnetron (80%). Nevertheless, this corresponds to gigawatts of power output at modest voltage (500 kV) and impedance (5 ohms). Experience has shown that, while it is straightforward to guild a MILO that oscillates at a specific frequency, maximum efficiency (power) cannot be achieved without careful consideration of the design. We have accomplished this using a load-limited MILO which uses an rf choke (Bragg reflector) at the upstream end to provide maximum feedback and, thereby, maximum power. We discuss various aspects of the design of this efficiency enhanced, multi-gigawatt, load-limited MILO, and present results of simulations and experiments. An upper limit on power efficiency is also discussed.