Relativistic Recirculating Planar Magnetrons.

Abstract

The recirculating planar magnetron (RPM) is a crossed-field device that combines the advantages of high-efficiency recirculating devices with those of planar devices: both large-area cathode (high current) and anode (improved thermal management). The RPM-12a is the first such experimental device designed and operated in the United States. The RPM-12a operates at pulsed voltages of -300 kV for durations of 300 to 500 ns with magnetic fields of 0.15-0.23 T. Experimental results have demonstrated generation of 175 MW high power microwave pulses between 50-250 ns in length in the vicinity of pi-mode at 1.01 GHz. Evidence of mode competition during operation led to the development of the Mode Control Cathode (MCC). Experimental operation of the RPM-12a in conjunction with the MCC-1, the first MCC prototype, increased the phase locking between the oscillators of the RPM from 25 percent up to 60 percent for shots with pulse-lengths in excess of 100 ns. A proof of principle power extraction experiment was performed using vane antennas to couple RF power into coaxial transmission lines. This extractor configuration, in conjunction with the RPM-12a, generated RF powers between 20-175 MW for durations of 50-250 ns, with peak electronic efficiency between 20-45 percent. Future experiments will focus on the optimized design of the coaxial all cavity extractor (CACE), which is a planar adaptation of the highly efficient “All Cavity Extractor” developed at the Air Force Research Lab.PhDNuclear Engineering & Radiological SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107317/1/mfronz_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/107317/2/mfronz_2.pd