Electromagnetic effects on plasma microturbulence and transport

Results are presented from three-dimensional kinetic-fluid simulations of pressure gradient driven microturbulence in toroidal long mean-free-path plasmas. A numerically efficient model which includes self-consistent magnetic fluctuations and nonadiabatic electron dynamics is employed. A transition from electrostatic ion-drift turbulence to Alfvénic turbulence is seen at modest values of the plasma pressure. Significant electromagnetic effects on heat conductivity are observed, including an increase as the ideal ballooning threshold is approached, particularly when electron Landau damping is included. Turbulent spectra show a number of similarities to experimental fluctuation measurements.