Modeling of capillary discharge plasmas for laser- and beam-driven wakefield accelerators*

Discharge capillary plasmas have been shown to increase both the peak energy and beam quality of laser wakefield accelerators. In addition to their use as active plasma lens, this promising technology may also serve next generation beam-driven schemes, for example hollow-channel plasmas for positron acceleration. These sources will be especially sensitive to variations in the plasma density profile and temporal evolution, and thus necessitate improved modeling efforts. Careful consideration of heat transfer and magnetic field penetration at the walls of the capillary are needed to resolve the dynamics at relevant time scales. We present simulations of capillary discharge waveguides in 2D geometries using FLASH, a publicly-available multi-physics code in development at the University of Chicago. We explore parametric modifications of the radial density profile by considering variations in the relevant capillary parameters, such as radius, geometry, wall conductivity, and gas pressure. Lastly, we consider coupling effects in longitudinally varying profiles, and plans to model hollow and near-hollow channel plasmas.