V. Petrzilka, FAST ELECTRONS GENERATION BY RF AND RANDOM-FIELDS NEAR THE ANTENNA .1. ONE-DIMENSIONAL MODEL AND REGULAR FIELDS, Czechoslovak journal of Physics, 47(2), 1997, pp. 183-196
Test particle motion and acceleration has been explored in strong radi
o frequency (RF) fields, for which quasilinear ponderomotive force app
roximation is not valid. By nonlinear acceleration in spatially varyin
g wave amplitude of RF travelling wave, electrons may be accelerated t
o time averaged velocities significantly larger than the RF wave phase
velocity, and than the boundary plasma thermal velocity, in RF fields
of several Volts per centimeter at wave frequency of 7 MHz. It is als
o demonstrated that even weak spatial gradients, much weaker than thos
e expected in experiments, of the RF wave field amplitude, have signif
icant consequences for the particle motion. Estimates are presented of
the total energy transferred from the near antenna RF field to the pl
asma due to the nonlinear electron acceleration effects.