The scaling of relativistic double-layer widths: Poisson–Vlasov solutions and particle-in-cell simulations

Abstract

In this paper the study of relativistic plasma double layers is described through the solution of the one-dimensional, unmagnetized, steady-state Poisson–Vlasov equations and by means of one-dimensional, unmagnetized, particle-in-cell simulations. The thickness versus potential-drop scaling law is extended to relativistic potential drops and relativistic plasma temperatures. The transition in the scaling law for ‘‘strong’’ double layers suggested by analytical two-beam models by Carlqvist [Astrophys. Space Sci. 87, 21 (1982)] is confirmed, and causality problems of standard double-layer simulation techniques applied to relativistic plasma systems are discussed.