Microwave radiation of a flare loop in the presence of whistler turbulence

Victor Melnikov, Pulkovo Observatory

Influence of whistlers on the nonthermal electrons' energy, pitch-angle, spatial distributions, and on characteristics of their gyrosynchrotron emission in a flaring loop is considered. We solve the problem in the frame of quasi-linear theory taking into account interrelation between whistler turbulence and nonthermal electrons propagating in an inhomogeneous magnetic loop. The system of kinetic equations in the Fokker–Planck approximation for fast electrons and in geometric optics approximation for whistlers is solved. As a result, we get electron temporal, spatial, energy, and pitch-angle distributions. Having found the fast electron distributions, the characteristics of their gyrosynchrotron microwave emission are calculated. It is shown that under some specific conditions interrelations of whistlers and electrons can considerably modify microwave emission characteristics of a flaring loop. The obtained findings are useful for microwave diagnostics of plasma turbulence and fast electron distributions in flare loops.