INVESTIGATION OF A LOAD-LIMITED, MAGNETICALLY INSULATED TRANSMISSION-LINE OSCILLATOR (MILO)

The magnetically insulated transmission line oscillator (MILO) is a cr ossed-field microwave tube that is closely related to the linear magne tron. We discuss research involving a MILO whose de operating characte ristics (voltage and impedance) are determined by a current-carrying l oad. The load also forms part of a unique power extraction scheme. We show that maximum power is obtained from the load-limited MILO when an RF choke is used for the upstream boundary. This efficiency-enhanced version of the load-limited MILO yields gigawatt-level output power in both experiments and numerical simulations, results of which are also presented. In addition, we use the parapotential theory of magnetical ly insulated transmission lines in conjunction with observed simulatio n results to obtain estimates of maximum spoke current, spoke drift ve locity, and maximum efficiency.