BURSTY WAVE INSTABILITIES IN OPEN DRIVEN PLASMAS

Wave instabilities in open, driven systems cause bursty emission. Loca l burst properties are combined with global power balance to predict t he source dynamics, energy conversion efficiency, and distribution of power levels. Sporadic growth near marginal stability is characterized by noninteger scaling exponents and an exponential distribution of po wer levels, unlike self-organized criticality or stochastic growth. Pr edictions are confirmed by particle-in-cell simulations of driven cycl otron instabilities. Solar microwave bursts are found to have the pred icted distribution of power levels.