KINETIC ALFVÉN TURBULENCE AND PARALLEL ELECTRIC FIELDS IN FLARE LOOPS

This study investigates the spectral structure of the kinetic Alfvén turbulence in the low-beta plasmas. We consider a strong turbulence resulting from collisions between counterpropagating wavepackets with equal energy. Our results show that (1) the spectra of the magnetic and electric field fluctuations display a transition at the electron inertial length scale, (2) the turbulence cascades mainly toward the magnetic field direction as the cascade scale is smaller than the electron inertial length, and (3) the parallel electric field increases as the turbulent scale decreases. We also show that the parallel electric field in the solar flare loops can be 102-104 times the Dreicer field as the turbulence reaches the electron inertial length scale.