Turbulence driven by two-stream instability in a magnetized plasma

Although the nonlinear evolution of the two-stream instability has been a s ubject of numerical and theoretical studies for many years, recent spacecra ft measurements of nonlinear electrostatic bipolar wave structures in the a uroral ionosphere have prompted new studies. Using parallel two-dimensional (2D) particle-in-cell electrostatic simulations with initially counterstre aming cold electrons in a magnetized plasma, the evolution of wave turbulen ce and particle distributions has been followed for over 10 000 inverse pla sma frequencies. Ions are introduced in the frame of one of the electron be ams (motivated by measurements). Wave turbulence evolves in at least five s eparate stages. After tens of omega(e)(-1), trapping produces bipolar wave structures with long range order across B. After hundreds of omega(e)(-1), the structures break up and whistlers appear. After thousands of omega(e)(- 1), ion cyclotron waves driven by a bump-on-tail in the evolved electron di stribution become prominent. After 6000 omega(e)(-1), the ion cyclotron wav es appear to undergo parametric decay into oblique waves. (C) 2000 American Institute of Physics. [S1070-664X(00)96205-0].