A NOTE ON RUNAWAY ELECTRONS IN THE PRESENCE OF KINETIC ALFVEN WAVES

It is shown by the quasilinear Fokker-Planck approach that the shear k inetic Alfven wave (KAW) cannot by itself produce runaway electrons, t hough it carries an electric field aligned with the ambient magnetic f ield. However, it can enhance the runaway production rate in case it p ropagates in presence of a background DC ambient electric field. There fore, this note answers the question raised by Hollweg (1981) concerni ng the runaway electrons and nonthermal emission supposedly produced b y KWA, without explanation until today. The main result presented here concerning the runaway production rate is valid for space or laborato ry plasmas where the KWA and an ambient DC electric field coexist.