Simulation of turbulent plasma heating by moderately strong oscillating two-stream instabilities

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Abstract
Numerical simulations are used to investigate plasma heating by the oscillating, two-stream instability at moderate amplitude. Substantially all the absorbed electromagnetic energy goes into production of a suprathermal electron population. A simple functional form describes the shape of the suprathermal distribution function, which is proportional to v−2 over a wide velocity range. This holds for a wide range of driving field amplitude. The multiplicative constant increases linearly with time within a simulation. The plasma electric field spectrum has a characteristic power law shape, which is interpreted as the result of the waves coming into quasi-thermal balance with electrons near their phase velocity. The results for the electron distribution function are in qualitative agreement with experiments by Dreicer, Ellis, and Ingraham, but they disagree with those of Mizuno and De Groot and of Porkolab.