Plasma channel development in polymineralic and porous rock aggregates

As humanity once again refocuses its efforts towards space exploration, future off-world missions are expected to be of substantially longer duration and be of far greater complexity. Future establishment of infrastructure such as off-world bases will necessitate effective in-situ resource utilization (ISRU) as a means to obtain and process necessary materials, since the weight and costs associated with resource transportation from Earth become prohibitive. As part of the Drilling and Integrated GigaHertz-Generated Energy Resource (DIGGER) collaboration, this work is focused on the modelling of plasma channel development in porous and polymineralic aggregate materials under impulse breakdown conditions. The main objective was to conduct a basic assessment of the effects of pores and rock heterogeneity on developed breakdown channel characteristics, reflective of a variety of potential rock types with different mineral compositions. The application of a Voronoi tessellation as an approximation of mineral grains is described, as is its coupling to a classical dielectric breakdown model to estimate the stochastic development of plasma channels inside rock aggregates. Simulated channel trajectories are in qualitative agreement with experimental rock-breaking patterns, while the effects of pores and rock heterogeneity are found likely to be key parameters that determine the channel penetration characteristics of high voltage rock breaking technology.