2026-09-23T22:14:05Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/122016 2024-03-01 col_2142_5131 col_2142_14800 com_2142_5130 com_2142_14799 com_2142_234

Rovey, Joshua L 2023-12 application/pdf en text Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo terms The student, Avinash Rao, accepted the attached license on 2023-11-27 at 10:13. The student, Avinash Rao, submitted this Thesis for approval on 2023-11-27 at 10:29. This Thesis was approved for publication on 2023-12-04 at 10:47. DSpace SAF Submission Ingestion Package generated from Vireo submission #20012 on 2024-03-01 at 13:14:59 Measurements of secondary mass flux from a surface bombarded by an [EMIM][BF4] electrospray plume Rao, Avinash Electrospray Secondary Mass Flux Qcm Facility Effects 2023-12-04 Electrospray propulsion systems operate by electrostatically extracting high speed droplets, clusters, and molecules from an ionic liquid propellant. These high speed species can impact and interact with surfaces in proximity of the propulsion device, producing an amorphous plume of secondary species. The aim of this research is to demonstrate a methodology for measuring the mass of a differential component of the secondary plume to better understand how electrospray thrusters interact with their terrestrial test facilities and their in-space environment. Experiments conducted utilized a quartz crystal microbalance to investigate the energy dependence of secondary mass flux as well as the angular distribution of secondary mass for high voltage and low voltage primary electrospray plumes. The secondary mass flux yields was observed to have very little dependence on the energy of the primary plume, with yield values contained within 6.822×10−14 ng ion-sr and 8.873×10−14 ng ion-sr over an order of magnitude of primary voltages. The angular distribution of the secondary plume produced by a low energy primary plume was relatively flat, with yields ranging from 7.391×10−14 ng ion-sr to 8.828×10−14 ng ion-sr over a range of 35◦ to 80◦. When spraying a high energy plume, the yield dropped from 7.304×10−14 ng ion-sr to 3.645×10−14 ng ion-sr when the polar position of the quartz crystal microbalance was swept from 35◦ to 80◦. These results indicate that the high energy plume produces a secondary plume with less mass than atomic carbon sputtering nickel, but more mass than if the carbon atoms simply bounced off the surface of the target. Results at varying primary energies require further investigation in a more pristine experimental environment to make any statements on the underlying effects. Text eng https://hdl.handle.net/2142/122016 Copyright 2023 Avinash Rao M.S. Thesis Aerospace Engineering University of Illinois at Urbana-Champaign Aerospace Engineering