A fluid–kinetic hybrid electron model for electromagnetic simulations

A fluid–kinetic hybrid electron model for electromagnetic simulations of finite-b plasmas is developed based on an expansion of the electron response using the electron–ion mass ratio as a small parameter. ~Here b is the ratio of plasma pressure to magnetic pressure.! The model accurately recovers low frequency plasma dielectric responses and faithfully preserves nonlinear kinetic effects ~e.g., phase space trapping!. Maximum numerical efficiency is achieved by overcoming the electron Courant condition and suppressing high frequency modes. This method is most useful for nonlinear kinetic ~particle-in-cell or Vlasov! simulations of electromagnetic microturbulence and Alfvénic instabilities in magnetized plasmas. © 2001 American Institute of Physics. @DOI: 10.1063/1.1356438# LETTERS