2025/09/01 by Abu Taqui Md Tahsin, Rafid Bendimerad, Adler Smith +3
paper · doi:10.2514/1.b39897
Gaining a comprehensive understanding of the electrospray plume composition and how it is affected by intermolecular collisions is critical to the performance prediction and advancement of the technology. The current study uses molecular dynamics modeling to identify and quantify the different types of processes that can ensue from the collisions between the monomer ions and the neutral molecules in the plume of an electrospray thruster operating with the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate ([Formula: see text]). Collision cross-sections are calculated for the identified collisional events as a function of the relative velocity of impact. The cross-section profiles provide quantitative insights into the relative importance of the different types of collisional interactions. We predict that 1) recombination and charge exchange are only significant at very low impact velocities [[Formula: see text]], 2) ionic fragmentation bears relevance in the impact velocity range [Formula: see text], and 3) covalent fragmentation dominates at the higher impact velocities [[Formula: see text]]. The results can be used to track changes in the composition of ion and neutral species due to collisions in the plume and the introduction of new species into the plume. The summary of collisional outcomes via cross-sections allows for their incorporation in larger-scale [Formula: see text]-body and particle-in-cell simulations of both individual and arrays of emitters.