TY - GEN
T1 - Ion-induced electron emission from surfaces bombarded by an emim-bf4 electrospray plume
AU - Klosterman, Matthew R.
AU - Rovey, Joshua L.
AU - Levin, Deborah
N1 - Funding Information:
The authors thank the NASA Early Stage Innovation program, federal award identification number 80NSSC19K0215, for funding the experimental work for this project and Dr. Thomas Liu at NASA Glenn Research Center for his contributions as an advisor for the project. Additionally, the authors thank Dr. Benjamin Prince and Dr. Shawn Miller for hosting Matthew Klosterman at the Air Force Research Laboratory at Kirtland to conduct preliminary externally wetted electrospray experiments.
Publisher Copyright:
© 2021, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
PY - 2021
Y1 - 2021
N2 - Experiments have been conducted at the University of Illinois Urbana Champaign Electric Propulsion Laboratory to study the ion-induced electron emission behavior of surfaces being bombarded by cations and anions in an [EMIM][BF4] electrospray plume. The surfaces tested include 6061 aluminum, carbon graphite, 316 stainless steel, and grade 5 titanium. Operation in cation mode resulted in yields from 0.5-2.5 emitted electrons per incident ion for emitter voltages of 2.2-3.0 kV. Additionally, the energy of electrons emitted from surfaces bombarded by cations increases linearly with emitter voltage and ranges from 80-165 eV depending on the surface material. A hysteresis effect is identified in the suppression of electron emission during cation bombardment and strongly depends on the target material and emitter voltage. Further, results indicate that 85-95% of the current from electron emission in cation mode travels upstream and is collected by the emitter. Operation in anion mode resulted in much lower yields of < 0.2 emitted electrons per incident ion over the range of 2.2-3.0 kV emitter voltages. However, evidence is presented showing that anion yields can increase to > 1 when surfaces are negatively biased.
AB - Experiments have been conducted at the University of Illinois Urbana Champaign Electric Propulsion Laboratory to study the ion-induced electron emission behavior of surfaces being bombarded by cations and anions in an [EMIM][BF4] electrospray plume. The surfaces tested include 6061 aluminum, carbon graphite, 316 stainless steel, and grade 5 titanium. Operation in cation mode resulted in yields from 0.5-2.5 emitted electrons per incident ion for emitter voltages of 2.2-3.0 kV. Additionally, the energy of electrons emitted from surfaces bombarded by cations increases linearly with emitter voltage and ranges from 80-165 eV depending on the surface material. A hysteresis effect is identified in the suppression of electron emission during cation bombardment and strongly depends on the target material and emitter voltage. Further, results indicate that 85-95% of the current from electron emission in cation mode travels upstream and is collected by the emitter. Operation in anion mode resulted in much lower yields of < 0.2 emitted electrons per incident ion over the range of 2.2-3.0 kV emitter voltages. However, evidence is presented showing that anion yields can increase to > 1 when surfaces are negatively biased.
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M3 - Conference contribution
AN - SCOPUS:85099822086
SN - 9781624106095
T3 - AIAA Scitech 2021 Forum
SP - 1
EP - 12
BT - AIAA Scitech 2021 Forum
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021
Y2 - 11 January 2021 through 15 January 2021
ER -