Bursty Wave Instabilities in Open Driven Plasmas

Abstract

Wave instabilities in open, driven systems cause bursty emission. Local burst properties are combined with global power balance to predict the 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 power levels, unlike self-organized criticality or stochastic growth. Predictions are confirmed by particle-in-cell simulations of driven cyclotron instabilities. Solar microwave bursts are found to have the predicted distribution of power levels.