Modified orbitron (M.O.) millimeterwave oscillators were constructed and the experiments began in order to improve the efficiency, pulse duration, and jitter time beyond the levels achievable with conventional orbitrons (C.O.s). The necessity of modifications was justified through characterization experiments of C.O.s. Computer simulation of a M.O. showed unambiguous development of the negative mass instability on an orbiting beamlet in a non-volatile logarithmic potential-well. Although significantly long pulses are also possible, extremely narrow pulses useful for a high resolution or impulse radar were successfully produced because of no jitters in a M.O. before the wave emission.
M. G. Niimura, M. G. Niimura,
"Modified orbitron experiments and simulation", Proc. SPIE 1576, 16th International Conference on Infrared and Millimeter Waves, 15766V (1 October 1991); doi: 10.1117/12.2297960; https://doi.org/10.1117/12.2297960