Bounce averaged trapped electron fluid equations for plasma turbulence

A novel set of nonlinear fluid equations for mirror-trapped electrons is developed which differs from conventional fluid equations in two main respects: (1) the trapped-fluid moments average over only two of three velocity space dimensions, retaining the full pitch angle dependence of the trapped electron dynamics, and (2) closure approximations include the effects of collisionless wave-particle resonances with the toroidal precession drift. Collisional pitch angle scattering is also included. By speeding up calculations by at least √mi/me, these bounce averaged fluid equations make possible realistic nonlinear simulations of turbulent particle transport and electron heat transport in tokamaks and other magnetically confined plasmas.