E × B configurations for high-throughput plasma mass separation: An outlook on possibilities and challenges

High-throughput plasma separation based on atomic mass holds promise for offering unique solutions to a variety of high-impact societal applications. Through the mass differential effects they exhibit, crossed-field configurations can in principle be exploited in various ways to separate ions based on atomic mass. Here, we review some of the E × B mass filter concepts proposed to date and underline how the practicality of these concepts is conditioned upon the ability to sustain a suitable perpendicular electric field in a plasma for parameters compatible with high-throughput operation. We show that while the limited present predictive capabilities do not make it possible to confirm this possibility, past experimental results suggest that end-electrode biasing may be effective, at least for certain electric field values. We conclude that a better understanding of cross-field conductivity is needed to confirm these results and confirm the potential of crossed-field configurations for high-throughput separation.