Modeling high radiation fraction L-mode plasmas in multiple configurations

The use of noble gas impurities as radiators in fusion scenarios can reduce power-handling demands in reactors and keep power well below the H-mode threshold power. We develop 0-D and 1-D models to show a reduction in power to the scrape off layer while maintaining relatively high power in the core and exhibiting improved L-mode performance compared to non-radiative regimes. We use these models to lever negative triangularity in tokamaks, which can improve confinement and thus correct some deficiencies of L-mode operation. The 1-D radiative L-mode tokamak model is compared to data measured in recent argon-based radiation feedback control experiments on DIII-D for model validation. We extend our analysis to compare the efficacy of radiators between plasmas of varying densities, magnetic fields, and aspect ratios in stellarators. We find that at reactor values radiative impurities reduce power to the first wall with minimal fuel dilution. We build off the 1-D scenarios using the STEP code for self-consistent operating points, supporting results from the 0-D and 1-D models. This work shows the benefits of radiative impurities in stellarator and tokamak configurations and the feasibility of L-mode tokamak reactors for commercial fusion, specifically with respect to power handling.