Splash plasma channels produced by picosecond laser pulses in argon gas for laser wakefield acceleration

Abstract

Short-lived, $\ensuremath{\sim}10\text{ }\text{ }\mathrm{ps}$, deep plasma channels, with their lengths of $\ensuremath{\sim}1\text{ }\text{ }\mathrm{mm}$ and diameters of $\ensuremath{\sim}20\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$, are observed and characterized in Ar gas jets irradiated by moderate intensity, $\ensuremath{\sim}{10}^{15--16}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$, laser pulses with a duration from subpicosecond to several picoseconds. The channels, upon 2D particle-in-cell simulations including ionization, fit well in the guiding of high intensity femtosecond laser pulses and, therefore, in laser wakefield acceleration with a controllable electron self-injection.