Design and modeling of plasma channels for laser plasma accelerators*

Structured plasma channels are an essential technology for driving high gradient, plasma-based acceleration and control of electron and positron beams for advanced concepts accelerators. Recent advances in laser technologies have enabled the generation of narrow plasma densities with lower on-axis densities than previously achieved through discharge capillaries. By carefully selecting the background gas and laser properties, these hydrodynamic, optically-field-ionized (HOFI) channels promise narrow, tunable plasma channels with unprecedented flexibility for guiding high intensity laser pulses. Despite significant improvements, existing models may produce modest discrepancies between the exact time dynamics, peak channel densities, and neutral density profiles generated by these interactions. We present on the development of 1D and 2D simulations of HOFI channel using the FLASH code, a publicly available radiation hydrodynamics code which has been previously applied to simulation of capillary discharge plasmas in similar operational regimes. We discuss progress in identifying and capturing sensitivities to initial conditions and discuss efforts to benchmark these simulations against experimental measurements of plasma channels.