Ultrafast Probing of Non-Equilibrium Plasmas Using Laser-Wakefield-Accelerated Electron Bunches

We explore the predominant physics behind the generation and evolution of an optical-field ionized plasma using electron bunches produced from a laser-plasma accelerator. The delay between the pump pulse and when the electron probe passes through the generated plasma has a direct effect on the measured energy of said electrons. Thus, we can use these electron bunches as a diagnostic to understand the dynamics of these non-equilibrium plasmas with picosecond temporal resolution. We employ particle-in-cell codes, including collisions and ionization, to model the plasma's electric fields that cause such an effect. We then simulate electrons passing through these electric fields at various points in its evolution and compare with experimental results.