  The results of a theoretical investigation of the energy loss of charged
particles in a magnetized classical plasma due to the electric field
fluctuations are reported. The energy loss for a test particle is calculated
through the linear-response theory. At vanishing magnetic field the electric
field fluctuations lead to an energy gain of the charged particle for all
velocities. It has been shown that in the presence of strong magnetic field
this effect occurs only at low-velocities. In the opposite case of
high-velocities the test particle systematically loses its energy due to the
interaction with a stochastic electric field. The net effect of the
fluctuations is the systematic reduction of the total energy loss (i.e. the sum
of the polarization and stochastic energy losses) at vanishing magnetic field
and reduction or enhancement at strong field depending on the velocity of the
particle. It is found that the energy loss of the slow heavy ion contains an
anomalous term which depends logarithmically on the projectile mass. The
physical origin of this anomalous term is the coupling between the cyclotron
motion of the plasma electrons and the long-wavelength, low-frequency
fluctuations produced by the projectile ion. This effect may strongly enhance
the stochastic energy gain of the particle.
