Energy properties and spatial plume profile of ionic liquid ion sources based on an array of porous metal strips

Abstract

An ionic liquid ion source (ILIS) is a kind of high brightness ion source capable of providing high-speed positive or negative ion beams. This paper presents a miniaturized ILIS based on an array of porous metal strips. The porous emitter array, integrated with seven 10 mm long strips, is fabricated using wire electrical discharge machining (WEDM) combined with electrochemical etching. The assembled ILIS is 30 mm×30 mm×17.5 mm in size and weighs less than 25 g. A series of experiments, including an I-V characteristic test, a retarding potential analyzer (RPA) test, and a spatial plume distribution test, have been conducted in vacuo to characterize the performance of the ILIS. Results show that the emitted current is up to about 800 μA and ion transparency is as high as 94%. Besides, RPA curves reveal that the total fragmentation rate of the emitted particles accounts for 48.8% in positive mode and 59.8% in negative mode. Further, with the increase in applied acceleration voltage, the voltage loss rises while the energy efficiency decreases. It is also found that the plume perpendicular to the strips has a higher divergence than the one parallel to the strips. A numerical simulation by COMSOL reveals that the electric field distribution between the two electrodes results in such a spatial plume profile.

Transient Flow in Porous Electrosprays

“…In contrast to cone emitters, these emitters will operate at a higher voltage due to only having one radius of curvature at the emission surface. On the other hand, only having curvature in one direction results in a narrow plume in the ridgewise direction of the wedge Liu, Kang, Deng, & Sun, 2021). Additionally, the long emission surface results in a tight collection of emission sites along the wedge without the need for emitter parallelization.…”

Study on the plume self-neutralization of ionic liquid electrospray thruster based on median potential

“…Researchers have conducted experimental and simulation studies to analyze the characteristics and selfneutralization effectiveness of plumes. It has been observed that ILET can operate in a pure ion mode, with monomers and dimers accounting for over 90% of the plume [28][29][30][31]. Courtney et al [16] investigated the coupling effect of temporal and spatial distributions on the self-neutralization of the plume.…”

Molecular Dynamics Simulations of Ion Extraction from Nanodroplets for Ionic Liquid Electrospray Thrusters

“…1 Schematic of the electrospray thruster potential analyzer (RPA) experiments have shown that variations in initial ion emission energy can influence the spacing between the cation-anion pairs. Past a certain energy threshold, the cation and anion molecules may overcome their attractive Coulomb forces, resulting in ion cluster dissociation or fragmentation of downstream solvated ion clusters [24,25]. Furthermore, Gamero-Castaño [26] implemented an Eulerian electrospray beam model based on the line-of-point-charges approach and demonstrated a strong dependence of charged droplet trajectories on their initial velocities.…”