Expansion of a cold non-neutral plasma slab

Abstract

This is the published version of a paper published in Physics of Plasmas. Citation for the original published paper (version of record):Karimov, A., Yu, M., Stenflo, L. (2014) Expansion of a cold non-neutral plasma slab. Plasmas, 21(12) Expansion of the ion and electron fronts of a cold non-neutral plasma slab with a quasi-neutral core bounded by layers containing only ions is investigated analytically and exact solutions are obtained. It is found that on average, the plasma expansion time scales linearly with the initial inverse ion plasma frequency as well as the degree of charge imbalance, and no expansion occurs if the cold plasma slab is stationary and overall neutral. However, in both cases, there can exist prominent oscillations on the electron front. V C 2014 AIP Publishing LLC. Physics of

Evolution of a Cold Non-neutral Electron–Positron Plasma Slab

“…Here we adopt a nonperturbative approach by first making an ansatz (through trial and error and intuitive guessing) on the spatial structures of the electric and velocity fields, then solve the ordinary differential equations (ODEs) for the temporal evolution of the given structure. [10,11] It is found that large-amplitude surface oscillations can be excited on the expansion fronts. Our results should be applicable for identifying and interpreting pair-plasma expansion phenomena in space and laboratory plasmas, as well as in numerical simulations of the latter.…”

“…As we are interested in the evolution of the fronts 𝑥 p (𝑡) and 𝑥 e (𝑡) of the cold electron and positron fluids as they expand into the vacuum, we shall adopt an integral approach similar to the momentum integral method of Karman for turbulent boundary layers in neutral fluids. [15] The hydrodynamic density and momentum conservation equations for the cold electron and positron plasmas are [10,11]…”

“…In electron-ion plasmas they are usually highly localized and strongly evanescent in the surface-normal directions. When they are not externally driven, [11,16,17] they are also relatively weak compared with the bulk plasma waves. However, as shown here, the surface oscillations can be of large amplitude for an electron-positron plasma.…”