Viscous limitation of large-amplitude pulses in two-component plasmas

¹  Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick Coventry CV4 7AL, UK, EU
²  Department of Theoretical Physics, Soltan Institute for Nuclear Studies - Hoża 69, 00-681 Warsaw, Poland, EU

Corresponding authors: g.rowlands@warwick.ac.uk einfeld@fuw.edu.pl

Received: 28 March 2008
Accepted: 20 May 2008

Abstract

Some time ago, we found an exact solution for nonlinear cold-plasma oscillations against a periodic ion background. The main and somewhat surprising physical effect due to the fixed ion background was the appearance of unbounded-electron density and electric-field intensity peaks. Along with others, we then tried to understand this in terms of realistic physical situations. Here we present a calculation indicating that these infinities can be removed by inclusion of viscous effects. A discussion of possible regions of validity of the model is given. For removal of infinities, the viscosity must be larger than a critical value depending on both the amplitude and spacing of the periodic ion background. Lagrangian coordinates are crucial in this calculation.