skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Small amplitude electron-acoustic double layers and solitons in fully relativistic plasmas of two-temperature electrons

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.3121242· OSTI ID:21276995
 [1]
  1. Department of Physics, Pusan National University, Busan 609-735 (Korea, Republic of)

A Korteweg-de Vries (KdV) equation for fully relativistic one dimensional plasmas of arbitrarily large streaming speed and temperature is derived by using the reductive perturbation method. For plasmas with more than two species of particles, the coefficient representing quadratic nonlinearity in KdV can vanish at critical values of certain parameters. To describe the nonlinear evolution at this critical parameter, a modified KdV (mKdV) equation that contains a cubic nonlinear term is obtained. Furthermore, a mixed mKdV equation pertaining to parameters in the vicinity of the critical values is also derived, in which the quadratic and cubic nonlinearities are both present. As an illustration of the results, the mixed mKdV equation is applied to a plasma comprised of cold ions and electrons having cold (T=0) and finite temperature components. For warm temperature T<<m{sub e}c{sup 2}, it is found that electron-acoustic nonlinear waves in the shape of double layer (kink) and solitary waves can exist, which have phase speed {radical}(3T/(4+{alpha})m{sub e}) in the rest frame of plasma, where {alpha} is the polytropic index of the equation of state of the warm electrons. The thickness of the transitional layer of the kink structure is of the order of Debye length {lambda}{sub D}. For extremely high temperature T>>m{sub e}c{sup 2}, it is also found that double layer and soliton-type solutions can exist with phase speed {radical}({alpha}-1)c, which is equal to the well known relativistic sound speed c/{radical}(3) for {alpha}=4/3. The thickness of the transition layer scales as {delta}{approx}T{sup -1/4}, which is different from the T<<m{sub e}c{sup 2} case.

OSTI ID:
21276995
Journal Information:
Physics of Plasmas, Vol. 16, Issue 4; Other Information: DOI: 10.1063/1.3121242; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
Country of Publication:
United States
Language:
English