Stochastic Acceleration of Low Energy Electrons in Cold Plasmas

Details Stochastic Acceleration of Low Energy Electrons in Cold Plasmas Stochastic Acceleration of Low Energy Electrons in Cold Plasmas

1996-10-19

arxiv.org/abs/astro-ph/9610148v1

Astronomy and Astrophysics

Astrophysics

22 pages, 13 figures, Latex, submitted to Astrophysical Journal

Scientific paper

10.1086/304168

We investigate the possibility of stochastic acceleration of background low-energy electrons by turbulent plasma waves. We consider the resonant interaction of the charged particles with all branches of the transverse plasma waves propagating parallel to a uniform magnetic field. Numerical results and asymptotic analytic solutions valid at non-relativistic and ultra-relativistic energies are obtained for the acceleration and scattering times of electrons. These times have a strong dependence on plasma parameter alpha = Omega_pe / Omega_e (the ratio of electron plasma frequency to electron gyrofrequency) and on the spectral index of plasma turbulence. It is shown that particles with energies above certain critical value may interact with higher frequency electromagnetic plasma waves and this interaction is allowed only in plasmas with alpha < 1. We show that for non-relativistic and semi-relativistic electrons in low-alpha plasmas the ratio of the acceleration time to the scattering time can be less than unity for a wide range of energies. From this we conclude that the transport equation derived for cosmic rays which requires this ratio to be much larger than one is not applicable at these energies. An approximate "critical" value of particle energy above which the dynamics of charged particles may be described by this transport equation is determined as a function of plasma parameters. We propose new transport equation for the opposite limit (energies less than this critical value) when the acceleration rate is much faster than the pitch angle scattering rate. This equation is needed to describe the electron dynamics in plasmas with alpha <= 0.1.

Affiliated with

Also associated with

No associations

Rating

Stochastic Acceleration of Low Energy Electrons in Cold Plasmas does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Stochastic Acceleration of Low Energy Electrons in Cold Plasmas, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stochastic Acceleration of Low Energy Electrons in Cold Plasmas will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-383491