Long-Term Stability of Boron Nitride Channel Walls in Hall Thrusters for Near-Solar Missions

Hall-effect thrusters have demonstrated exceptional efficiency for planetary missions, but their long-term stability in heliophysics expeditions, where spacecraft operate in extreme radiation and plasma environments near the Sun, remains underexplored. Boron nitride (BN), the standard channel-wall material, must withstand not only strong radial magnetic fields but also intense fluxes of γ-rays, UV/X-rays, and continual bombardment by energetic solar particles. I present a computational study of BN stability under conditions relevant to near-solar electric propulsion. Radiation transport simulations using solar spectra quantify energy deposition and secondary particle fluxes in BN; density functional theory models defect energetics, electronic states, and work function shifts; and molecular dynamics predicts thermal conductivity degradation with defect accumulation. Particle-in-cell modeling provides sheath conditions and wall flux distributions for realistic Hall-thruster fields (0–0.05 T). Integrated results suggest solar-driven defect accumulation alters dielectric response, secondary electron emission, and thermal management, with direct consequences for thruster efficiency and lifetime.