  The kinetic effects of electrons are important to long wavelength
magnetohydrodynamic(MHD)instabilities and short wavelength drift-Alfvenic
instabilities responsible for turbulence transport in magnetized plasmas, since
the non-adiabatic electron can interact with, modify and drive the low
frequency instabilities. A novel conservative split weight scheme is proposed
for the electromagnetic simulation with drift kinetic electrons in tokamak
plasmas, which shows great computational advantages that there is no numerical
constrain of electron skin depth on the perpendicular grid size without
sacrificing any physics. Both kinetic Alfven wave and collision-less tearing
mode are verified by using this model, which has already been implemented into
the gyrokinetic toroidal code(GTC). This model will be used for the micro
tearing mode and neoclassical tearing mode simulation based on the first
principle in the future.
