Dissertations / Theses: 'Ion'

6

Adelhelm, Philipp. "From Lithium-Ion to Sodium-Ion Batteries." Diffusion fundamentals 21 (2014) 5, S.1, 2014. https://ul.qucosa.de/id/qucosa%3A32397.

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7

Ebanezar, John Angelin [Verfasser]. "Negative Ion formation in Ion-Molecule and Ion-Surface collisions / Angelin Ebanezar John." Greifswald : Universitätsbibliothek Greifswald, 2014. http://d-nb.info/1061064654/34.

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8

Shen, Kuan-Hsuan. "Modeling ion conduction through salt-doped polymers: Morphology, ion solvation, and ion correlations." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595422569403378.

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9

Orban, Istvan. "Electron - Ion Recombination Studies of Astrophysically Relevant Ions : Storage Ring and Electron Beam Ion Trap Based Measurements /." Stockholm : Department of Physics, Stockholm University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-33254.

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Diss. (sammanfattning) Stockholm : Stockholms universitet, 2010.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 6: Submitted. Paper 7: Submitted. Härtill 7 uppsatser.

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10

Bissonnette, Martine C. "Ion/radical and ion/molecule complexes and ion structure assignments in the gas phase." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7731.

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The fragmentation mechanism of ionized neopentanol, (CH$\sb3$)$\sb3$CCH$\sb2$OH$\sp{+-}$, has been studied in great detail along with other C$\sb5$H$\sb $H$\sp{+-}$ isomers. The use of $\sp $C and D labelling was found an essential tool to establish the relation between the other species involved in the dissociation of neopentanol. The involvement of (CH$\sb3$)$\sb2$C$\sp{\cdot}$CH$\sb2\sp+$(O)HCH$\sb3$, (CH$\sb3$)$\sb3$C$\sp+$(O)HCH$\sb2$ and (CH$\sb3$)$\sb2$($\sp\cdot$CH$\sb2$)CCH$\sb2\sp+$OH$\sb2$ was essential to explain the H/D label exchange occurring upon fragmentation of neopentyl alcohol. An ion-dipole complex between methanol and ionized methyl propene is proposed as the final intermediate which leads directly to the products, methanol and ionized methyl propene. The results of the investigation of C$\sb7$H$\sb5\sp+$ ions from various precursor molecules are also described. The following compounds, which all produce C$\sb7$H$\sb5\sp+$ ions, were studied: benzyl acetate, benzyl formate, benzyl alcohol, 2-bromocyclopropabenzene, 1,6-heptadiyne and 1,5-decadiyne. According to the metastable ion (MI) mass spectra and the He collision induced dissociation (CID) of m/z 89 ions, it is suggested that four structures exist. (Abstract shortened by UMI.)

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11

Li, Libing. "Strategies for secondary ion yield enhancements in focused ion beam secondary ion mass spectrometry." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/11806.

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12

Soyk, Matthew W. "Instrumentation development for coupling ion/ion reactions and ion mobility in biological mass spectrometry." [Ames, Iowa : Iowa State University], 2008.

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13

Bozkurt, Bilge. "Dynamic Ion Behavior In Plasma Source Ion Implantation." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607025/index.pdf.

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The aim of this work is to analytically treat the dynamic ion behavior during the evolution of the ion matrix sheath, considering the industrial application plasma source ion implantation for both planar and cylindrical targets, and then to de-velop a code that simulates this dynamic ion behavior numerically. If the sepa-ration between the electrodes in a discharge tube is small, upon the application of a large potential between the electrodes, an ion matrix sheath is formed, which fills the whole inter-electrode space. After a short time, the ion matrix sheath starts moving towards the cathode and disappears there. Two regions are formed as the matrix sheath evolves. The potential profiles of these two regions are derived and the ion flux on the cathode is estimated. Then, by us-ing the finite-differences method, the problem is simulated numerically. It has been seen that the results of both analytical calculations and numerical simula-tions are in a good agreement.

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14

Allan, Scott Young. "Ion Energy Measurements in Plasma Immersion Ion Implantation." Thesis, The University of Sydney, 2009. http://hdl.handle.net/2123/5338.

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This thesis investigates ion energy distributions (IEDs) during plasma immersion ion implantation (PIII). PIII is a surface modification technique where an object is placed in a plasma and pulse biased with large negative voltages. The energy distribution of implanted ions is important in determining the extent of surface modifications. IED measurements were made during PIII using a pulse biased retarding field energy analyser (RFEA) in a capacitive RF plasma. Experimental results were compared with those obtained from a two dimensional numerical simulation to help explain the origins of features in the IEDs. Time resolved IED measurements were made during PIII of metal and insulator materials and investigated the effects of the use of a metal mesh over the surface and the effects of insulator surface charging. When the pulse was applied to the RFEA, the ion flux rapidly increased above the pulse-off value and then slowly decreased during the pulse. The ion density during the pulse decreased below values measured when no pulse was applied to the RFEA. This indicates that the depletion of ions by the pulsed RFEA is greater than the generation of ions in the plasma. IEDs measured during pulse biasing showed a peak close to the maximum sheath potential energy and a spread of ions with energies between zero and the maximum ion energy. Simulations showed that the peak is produced by ions from the sheath edge directly above the RFEA inlet and that the spread of ions is produced by ions which collide in the sheath and/or arrive at the RFEA with trajectories not perpendicular to the RFEA front surface. The RFEA discriminates ions based only on the component of their velocity perpendicular to the RFEA front surface. To minimise the effects of surface charging during PIII of an insulator, a metal mesh can be placed over the insulator and pulse biased together with the object. Measurements were made with metal mesh cylinders fixed to the metal RFEA front surface. The use of a mesh gave a larger ion flux compared to the use of no mesh. The larger ion flux is attributed to the larger plasma-sheath surface area around the mesh. The measured IEDs showed a low, medium and high energy peak. Simulation results show that the high energy peak is produced by ions from the sheath above the mesh top. The low energy peak is produced by ions trapped by the space charge potential hump which forms inside the mesh. The medium energy peak is produced by ions from the sheath above the mesh corners. Simulations showed that the IED is dependent on measurement position under the mesh. To investigate the effects of insulator surface charging during PIII, IED measurements were made through an orifice cut into a Mylar insulator on the RFEA front surface. With no mesh, during the pulse, an increasing number of lower energy ions were measured. Simulation results show that this is due to the increase in the curvature of the sheath over the orifice region as the insulator potential increases due to surface charging. The surface charging observed at the insulator would reduce the average energy of ions implanted into the insulator during the pulse. Compared to the case with no mesh, the use of a mesh increases the total ion flux and the ion flux during the early stages of the pulse but does not eliminate surface charging. During the pulse, compared to the no mesh case, a larger number of lower energy ions are measured. Simulation results show that this is caused by the potential in the mesh region which affects the trajectories of ions from the sheaths above the mesh top and corners and results in more ions being measured with trajectories less than ninety degrees to the RFEA front surface.

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15

Allan, Scott Young. "Ion Energy Measurements in Plasma Immersion Ion Implantation." The School of Physics. The Faculty of Science, 2009. http://hdl.handle.net/2123/5338.

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Doctor of Philosophy (PhD)
This thesis investigates ion energy distributions (IEDs) during plasma immersion ion implantation (PIII). PIII is a surface modification technique where an object is placed in a plasma and pulse biased with large negative voltages. The energy distribution of implanted ions is important in determining the extent of surface modifications. IED measurements were made during PIII using a pulse biased retarding field energy analyser (RFEA) in a capacitive RF plasma. Experimental results were compared with those obtained from a two dimensional numerical simulation to help explain the origins of features in the IEDs. Time resolved IED measurements were made during PIII of metal and insulator materials and investigated the effects of the use of a metal mesh over the surface and the effects of insulator surface charging. When the pulse was applied to the RFEA, the ion flux rapidly increased above the pulse-off value and then slowly decreased during the pulse. The ion density during the pulse decreased below values measured when no pulse was applied to the RFEA. This indicates that the depletion of ions by the pulsed RFEA is greater than the generation of ions in the plasma. IEDs measured during pulse biasing showed a peak close to the maximum sheath potential energy and a spread of ions with energies between zero and the maximum ion energy. Simulations showed that the peak is produced by ions from the sheath edge directly above the RFEA inlet and that the spread of ions is produced by ions which collide in the sheath and/or arrive at the RFEA with trajectories not perpendicular to the RFEA front surface. The RFEA discriminates ions based only on the component of their velocity perpendicular to the RFEA front surface. To minimise the effects of surface charging during PIII of an insulator, a metal mesh can be placed over the insulator and pulse biased together with the object. Measurements were made with metal mesh cylinders fixed to the metal RFEA front surface. The use of a mesh gave a larger ion flux compared to the use of no mesh. The larger ion flux is attributed to the larger plasma-sheath surface area around the mesh. The measured IEDs showed a low, medium and high energy peak. Simulation results show that the high energy peak is produced by ions from the sheath above the mesh top. The low energy peak is produced by ions trapped by the space charge potential hump which forms inside the mesh. The medium energy peak is produced by ions from the sheath above the mesh corners. Simulations showed that the IED is dependent on measurement position under the mesh. To investigate the effects of insulator surface charging during PIII, IED measurements were made through an orifice cut into a Mylar insulator on the RFEA front surface. With no mesh, during the pulse, an increasing number of lower energy ions were measured. Simulation results show that this is due to the increase in the curvature of the sheath over the orifice region as the insulator potential increases due to surface charging. The surface charging observed at the insulator would reduce the average energy of ions implanted into the insulator during the pulse. Compared to the case with no mesh, the use of a mesh increases the total ion flux and the ion flux during the early stages of the pulse but does not eliminate surface charging. During the pulse, compared to the no mesh case, a larger number of lower energy ions are measured. Simulation results show that this is caused by the potential in the mesh region which affects the trajectories of ions from the sheaths above the mesh top and corners and results in more ions being measured with trajectories less than ninety degrees to the RFEA front surface.

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16

Choi, Jong-Ho Okumura Mitchio Okumura Mitchio. "Infrared spectroscopy of molecular ions and ion-solvent clusters /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-09252007-09111.

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17

Whitlow, Harry James. "Ion-materials interactions and their application." Thesis, University of Bath, 1998. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285272.

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18

McVeigh, Ryan. "Biologically enhanced ion exchange of ammonium ion using clinoptilolite." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247390.

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19

Sterling, Robin C. "Ytterbium ion trapping and microfabrication of ion trap arrays." Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/39684/.

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Over the past 15 years ion traps have demonstrated all the building blocks required of a quantum computer. Despite this success, trapping ions remains a challenging task, with the requirement for extensive laser systems and vacuum systems to perform operations on only a handful of qubits. To scale these proof of principle experiments into something that can outperform a classical computer requires an advancement in the trap technologies that will allow multiple trapping zones, junctions and utilize scalable fabrication technologies. I will discuss the construction of an ion trapping experiment, focussing on my work towards the laser stabilization and ion trap design but also covering the experimental setup as a whole. The vacuum system that I designed allows the mounting and testing of a variety of ion trap chips, with versatile optical access and a fast turn around time. I will also present the design and fabrication of a microfabricated Y junction and a 2- dimensional ion trap lattice. I achieve a suppression of barrier height and small variation of secular frequency through the Y junction, aiding to the junctions applicability to adiabatic shuttling operations. I also report the design and fabrication of a 2-D ion trap lattice. Such structures have been proposed as a means to implement quantum simulators and to my knowledge is the first microfabricated lattice trap. Electrical testing of the trap structures was undertaken to investigate the breakdown voltage of microfabricated structures with both static and radio frequency voltages. The results from these tests negate the concern over reduced rf voltage breakdown and in fact demonstrates breakdown voltages significantly above that typically required for ion trapping. This may allow ion traps to be designed to operate with higher voltages and greater ion-electrode separations, reducing anomalous heating. Lastly I present my work towards the implementation of magnetic fields gradients and microwaves on chip. This may allow coupling of the ions internal state to its motion using microwaves, thus reducing the requirements for the use of laser systems.

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20

Rosenberg, Ron S. M. Massachusetts Institute of Technology. "Screen-printed ion selective electrodes for soil ion detection." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/110884.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 187-192).
Rural Indian farmers lack an available, affordable, usable, and actionable means to diagnose soil health, which is a prerequisite for judicious application of fertilizer. Although government labs and mobile kits are available, these fail to meet the aforementioned qualities; as a result fewer than 5% of rural Indian farmers have ever performed a soil test. This thesis details the design and characterization of a point-of- use soil testing device, comprising a set of disposable ion-selective electrode (ISE) strips and a handheld electrochemical reader, which together transduce soil analyte concentrations into a numeric input for a mobile-phone based fertilizer recommendation engine. As a proof-of-concept, potassium (K+) selective electrodes are studied, because K+ is essential to plant growth and reproduction. The strips employ a simple two electrode system, wherein carbon nanotube and silver chloride inks are the electrode contacts, plasticizer-free butyl acrylate ion selective membranes are located on the working electrodes, and sodium-chloride doped polyvinyl butyral membranes provide stable reference potentials. The electrodes were fabricated by a combined screen printing and drop casting process, and the protocol, extraction solution, and reference potential stability were tuned to maximize ISE performance and repeatability. Using a mathematical model and supporting experiments, we verified that hydrogen selectivity determines the detection limit, and furthermore, that scientists can tune the ionophore-ionic site ratio to minimize this effect. Using the final electrode fabrication process, a set of 20 full ISE devices in the presence of 0.02M SrCl2 extraction solution were shown to have sub-uM detection limits and near-Nernstian average sensitivity (61 mV/decade). When compared to ICP data for a set of 30 soil samples using the final reader, the sensors demonstrated a 0.898 correlation factor. Workshops in India were conducted to determine user needs and corresponding product attributes, as well as a "usability index" for the system assessed across farmer demographics. The favorable system performance proves that solid-state ISEs are a promising technology for soil diagnostics in resource-constrained environments.
by Ron Rosenberg.
S.M.

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21

Perez, Martinez Carla S. (Carla Sofia). "Engineering ionic liquid ion sources for ion beam applications." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105605.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 177-186).
Ionic liquid ion sources (ILIS) are devices capable of producing positive and negative molecular ion beams through field evaporation from room-temperature molten salts. If sufficiently high hydraulic impedance from the liquid-supporting emitter is provided such that the ratio of flow rate Q to liquid's electrical conductivity K is sufficiently small, a pure ionic regime (PIR) can be achieved, in contrast with traditional electrosprays that produce charged droplets, or mixtures of droplets and ions. The PIR provides high current density from a point source, making ionic liquid ion beams suitable for use in focused ion beam (FIB) applications. The use of ionic liquids in focused ion beams could allow the production of sub-100 nm beams of up to kiloDalton organic ions as well as reactive species, with the possibility of engineering ionic liquid properties for a specific application. In addition, using micro-fabricated and nano-structured emitter arrays operating in the PIR can give access to efficient and compact positive or negative ion sources, for applications from spacecraft thrusters to deep reactive ion etchers (DRIE). There is a need for novel tip geometries and materials that favor the stable formation of a single emission site on the liquid supporting structure, while providing a continuous liquid supply compatible with the PIR. In this thesis, porous carbon based on resorcinol-formaldehyde xerogels is introduced as an emitter substrate. The target pore sizes and emitter geometries to attain the PIR are obtained through analytical estimates. The carbon xerogel can be shaped to the required micron-sized geometry through mechanical polishing. Time-of-flight mass (TOF) spectrometry is used to verify that charged particle beams produced from the mechanically polished carbon xerogel source, infused with the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF₄), contain solvated ions exclusively. In the case of the liquid 1-ethyl-3-methylimidazolium bis(trifluorometrylsulfonyl)imide (EMI-Im), mixed ion-drop operation is obtained. Laser micro-machining has been validated as a manufacturing technique to shape carbon xerogel into emitters. This technique should allow the production of emitter arrays for DRIE or propulsion applications, and allow the reproducible fabrication of emitters for FIB. Stable emission has been obtained from a laser micromachined tip infused with the ionic liquid EMI-BF₄ . The results of TOF and retarding potential analysis (RPA) experiments indicate that the emission consists mostly of monomers and dimers, and that a small fraction (< 5%) of the beam might be composed of cluster ions with greater degrees of solvation. To conclude, the thesis reports on the etching properties of the beams obtained from ILIS, both in the case of traditional externally wetted tungsten sources and with the novel carbon xerogel emitter technology. The W ILIS etches silicon with sputtering rates between 6 and 35 atoms of silicon removed per incident ion at 15 keV irradiation energies, whereas the carbon xerogel ILIS has been used to etch gold, silicon and gallium nitride with sputtering rates in the order of 10 for irradiation energies between 2 and 7 keV.
by Carla S. Perez Martinez.
Ph. D.

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22

Kuzema, O. S., and P. O. Kuzema. "Ion Probe with Primary ion Beam Prism Mass Separator." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35627.

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It has been considered the ion-optical properties and characteristics of ion microprobe analyzer in which the primary ion beam mass separation is realized by the magnetic prism, and the beam spherical capacitor is used in the secondary ion analyzing system as energy analyzer which form parallel ion beam at the mass analyzer inlet. It has allowed to improve the instrument parameters and to scale down its overall dimension. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35627

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23

Shi, Yu. "Single-ion Hydration and Ion Association in Aqueous Solutions." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439310243.

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24

Kellerbauer, Alban. "Production of a cooled ion beam by manipulation of 60-keV ions into a radio-frequency quadrupole ion guide." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0025/MQ50804.pdf.

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25

Hohenschutz, Max. "Nano-ions in interaction with non-ionic surfactant self-assemblies." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTS064.

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Les ions de taille nanométrique (nano-ions), tels que les clusters ioniques de bore, les polyoxométalates (POM) et les grands ions organiques, ont suscité un intérêt remarquable ces dernières années en raison de leur capacité à s’adsorber ou se lier à des systèmes chimiques électriquement neutres, tels que les molécules hôtes macrocycliques, les nanoparticules, les tensioactifs et les polymères, etc. Il a été démontré que ces processus d'adsorption ou de liaison sont induits par un phénomène médié par solvant, l'effet chaotropique, qui pousse le nano-ion de la masse d'eau vers une interface. Ainsi, l'eau d'hydratation de l'ion et de l'interface est libérée dans la masse d'eau, ce qui entraîne une restitution de la structure intrinsèque de l'eau. Cet effet est particulièrement fort pour les nano-ions. Ils sont par conséquent appelés ions superchaotropiques ou hydrophobes dans le prolongement des ions classiques (faiblement) chaotropiques tels que le SCN-. Tous les superchaotropes couramment étudiés, bien que chimiquement divers, partagent des caractéristiques physiques telles qu'une faible densité de charge et une grande polarisabilité. Les effets des nano-ions sur les auto-assemblages de tensioactifs non ioniques éthoxylés, les phases micellaires et bicouches, sont ici élucidés pour tirer des conclusions sur leur nature chaotropique et/ou hydrophobe. En combinant la diffusion aux petits angles des neutrons et des rayons X (SANS et SAXS), et les diagrammes de phase, les systèmes tensioactifs non ioniques/nano-ion sont examinés et comparés, du nanomètre à l'échelle macroscopique. Ainsi, il est montré que tous les nano-ions étudiés induisent un chargement électrique des assemblages de tensioactifs ainsi qu'une déshydratation des têtes de tensioactif non-ionique. En outre, les ions chaotropiques ou hydrophobes diffèrent dans leurs effets sur la forme micellaire. Les ions chaotropiques entraînent les micelles allongées de tensioactif non-ionique vers les micelles sphériques (augmentation de la courbure), tandis que les ions hydrophobes provoquent une transition vers les phases bicouches (diminution de la courbure). Il est conclu que les nano-ions superchaotropiques agissent comme des tensioactifs ioniques car leur ajout à des systèmes de tensioactifs non ioniques provoque un effet de charge. Cependant, les nano-ions et les tensioactifs ioniques sont fondamentalement différents par leur association avec l'ensemble des tensioactifs non ioniques. Le nano-ion s'adsorbe sur les têtes des tensioactifs non ioniques par effet chaotropique, tandis que le tensioactif ionique s'ancre dans les micelles entre les queues des tensioactifs non ioniques par effet hydrophobe. La comparaison des effets de l'ajout de nano-ions ou de tensioactifs ioniques à des tensioactifs non ioniques a été approfondie sur les mousses. Les mousses ont été étudiées en ce qui concerne l'épaisseur du film de mousse, le drainage dans le temps et la stabilité, respectivement en utilisant la SANS, l'analyse d'image et la conductométrie. Le POM superchaotropique testé (SiW12O404-, SiW) ne mousse pas dans l'eau contrairement au SDS classique de tensioactif ionique. Néanmoins, l'ajout de petites quantités de SiW ou de SDS à une solution moussante de tensioactif non ionique a permis d'obtenir des mousses plus humides avec une durée de vie plus longue. Entre-temps, l'épaisseur du film de mousse (déterminée en SANS) est augmentée en raison de la charge électrique des monocouches de tensioactifs non ioniques dans le film de mousse. Il est conclu que le comportement remarquable des nano-ions - ici sur les systèmes tensioactifs non ioniques - peut être étendu aux systèmes colloïdaux, tels que les mousses, les polymères, les protéines ou les nanoparticules. Cette thèse démontre que le comportement superchaotropique des nano-ions est un outil polyvalent qui peut être utilisé dans de nouvelles formulations de matériaux et d'applications de la matière molle
Nanometer-sized ions (nano-ions), such as ionic boron clusters, polyoxometalates (POMs) and large organic ions, have spawned remarkable interest in recent years due to their ability to adsorb or bind to electrically neutral chemical systems, such as macrocyclic host molecules, colloidal nano-particles, surfactants and polymers etc. The underlying adsorption or binding processes were shown to be driven by a solvent-mediated phenomenon, the chaotropic effect, which drives the nano-ion from the water bulk towards an interface. Thus, hydration water of the ion and the interface is released into the bulk resulting in a bulk water structure recovery. This effect is particularly strong for nano-ions. Therefore, they were termed superchaotropic or hydrophobic ions as an extension to classical (weakly) chaotropic ions such as SCN-. All commonly studied superchaotropes, though chemically diverse, share physical characteristics such as low charge density and high polarizability. Herein, the effects of nano-ions on ethoxylated non-ionic surfactant self-assemblies, micellar and bilayer phases, are elucidated to draw conclusions on their chaotropic and/or hydrophobic nature. By combining small angle scattering of neutrons and x-rays (SANS and SAXS), and phase diagrams, non-ionic surfactant/nano-ion systems are examined and compared, from the nanometer to the macroscopic scale. Thus, all studied nano-ions are found to induce a charging of the surfactant assemblies along with a dehydration of the non-ionic surfactant head groups. Furthermore, chaotropic and hydrophobic ions differ in their effects on the micellar shape. Superchaotropic ions drive the elongated non-ionic surfactant micelles towards spherical micelles (increase in curvature), whereas hydrophobic ions cause a transition towards bilayer phases (decrease in curvature). It is concluded that superchaotropic nano-ions act like ionic surfactants because their addition to non-ionic surfactant systems causes a charging effect. However, nano-ions and ionic surfactants are fundamentally different by their association with the non-ionic surfactant assembly. The nano-ion adsorbs to the non-ionic surfactant heads by the chaotropic effect, while the ionic surfactant anchors into the micelles between the non-ionic surfactant tails by the hydrophobic effect. The comparison of the effects of adding nano-ions or ionic surfactant to non-ionic surfactant was further investigated on foams. The foams were investigated regarding foam film thickness, drainage over time and stability, respectively using SANS, image analysis and conductometry. The tested superchaotropic POM (SiW12O404-, SiW) does not foam in water in contrast to the classical ionic surfactant SDS. Nevertheless, addition of small amounts of SiW or SDS to a non-ionic surfactant foaming solution resulted in wetter foams with longer lifetimes. Meanwhile, the foam film thickness (determined in SANS) is increased due to the electric charging of the non-ionic surfactant monolayers in the foam film. It is concluded that the remarkable behavior of nano-ions – herein on non-ionic surfactant systems – can be extended to colloidal systems, such as foams, polymers, proteins or nanoparticles. This thesis demonstrates that the superchaotropic behavior of nano-ions is a versatile tool to be used in novel formulations of soft matter materials and applications

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26

Marto, Jarrod A. "External Ion Injection and Applications of Ion Axialization in Fourier Transform Ion Cyclotron Resonance Mass Spectrometry /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487868114113087.

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27

Torres, Theresa Ann. "Development of Fourier transform ion cyclotron resonance mass spectrometry for the study of ion-ion reactions /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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28

Li, Ailin. "Miniaturization of Linear Ion Traps and Ion Motion Study in a Toroidal Ion Trap Mass Analyzer." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6503.

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I describe the miniaturization of a linear-type ion trap mass spectrometer for possible applications in portable chemical analysis, and demonstrate the advantages of using lithographically patterned electrode plates in realizing an ion trap with dimension r0 less than 1 mm. The focus of the work was to demonstrate the viability and feasibility of the patterned electrode approach to trap miniaturization, and also to discover potential obstacles to its use. Planar ceramic substrates were patterned with metal electrodes using photolithography. Plates that were originally used in a linear trap with a half-spacing (r0) of 2.19 mm were positioned much closer together such that r0 = 0.95 mm. A capacitive voltage divider provided different radiofrequency (RF) amplitudes to each electrode, and the capacitor values were adjusted to provide the correct electric field at this closer spacing. Electron ionization mass spectra of toluene and dichloromethane demonstrate instrument performance with better than unit mass resolution. Compared with the larger plate spacing, the signal intensity is reduced, corresponding to the reduced trapping capacity of the smaller device, but the mass resolution of the larger device is retained. A further miniaturized linear ion trap with a half-spacing of 362 µm was designed and tested. A series of obstacles and troubleshooting on ion source, analytical method, and electronics were present. These experiments show promise for further miniaturization using patterned ceramic plates and provide a guide for the ion trap miniaturization. The feasibility of a wire linear ion trap was also demonstrated. Unit mass resolution was obtained, indicating a promise for further optimization and miniaturization of the wire linear ion trap. In addition to the practical experiments on the miniaturized linear ion traps, I theoretically studied ion motion in the toroidal ion trap using SIMION simulations, which show classical chaotic behavior of single ions. The chaotic motion is a result of the non-linear components of the electric fields as established by the trap electrodes, and not by Coulombic interaction from other ions. The chaotic behavior was observed specifically in the ejection direction of ions located in non-linear resonance bands within and adjacent to the region of stable trapping. The non-linear bands crossing through the stability regions correspond to hexapole resonance conditions, while the chaotic ejection observed immediately adjacent to the stable trapping region corresponds to a "fuzzy" ejection boundary. Fractal-like patterns were obtained in a series of zoomed-in regions of the stability diagram.

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29

Fowles, Jonathon Richard. "Characterization of the skeletal muscle sodium ion-potassium ion-ATPase, and the acute effects of exercise on sodium ion-potassium ion-ATPase activity." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ65239.pdf.

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30

Bäckström, Erik. "LIfetimes measurement states in ions at an ion storage ring." Licentiate thesis, Stockholms universitet, Fysikum, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-67024.

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31

Russell, Elspeth. "Ions and ion transport mechanisms in the developing chick embryo." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287301.

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32

Fisher, Zachary (Zachary Kenneth). "Shuttling of ions for characterization of a microfabricated ion trap." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78510.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 65-67).
In this thesis, I present experimental results demonstrating the characterization of a planar Paul trap. I discuss the theory of ion trapping and analyze the voltages required for shuttling. Next, the characteristics of a digital-to-analog converter (DAC) are calibrated, and this instrument is integrated into trapping experiments to test the viability of the analytic model. Combining theory with the capabilities of the DAC, I calculate that the new experimental system is capable of 3 nm-precision control of the ion. Taking advantage of this ion control, I present initial results for a lock-in micromotion detection method which minimizes stray fields around an ⁸⁸Sr+ ion using Fourier analysis on the ion fluorescence to detect resonance at the secular frequencies. This method drives the ion oscillator across resonance using a superimposed radiofrequency electric field, which allows for off-axis field measurements as well as trap characterization. With this method, the secular frequencies of the trap are measured and are observed to fall within 3.50[sigma] of the analytic prediction.
by Zachary Fisher.
S.B.

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33

Ali, Safdar. "Electron - Ion Recombination Data for Plasma Applications : Results from Electron Beam Ion Trap and Ion Storage Ring." Doctoral thesis, Stockholms universitet, Fysikum, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-75311.

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This thesis contains results of electron-ion recombination processes in atomic ions relevant for plasma applications. The measurements were performed at the Stockholm Refrigerated Electron Beam Ion Trap (R-EBIT) and at the CRYRING heavy-ion storage ring. Dielectronic recombination (DR) cross sections, resonant strengths, rate coefficients and energy peak positions in H-like and He-like S are obtained for the first time from the EBIT measurements. Furthermore, the experimentally obtained DR resonant strengths are used to check the behaviour of a scaling formula for low Z, H-and He-like iso-electronic sequences and to update the fitting parameters. KLL DR peak positions for initially He- to B-like Ar ions are obtained experimentally from the EBIT measurements. Both the results from highly charged sulfur and argon are compared with the calculations performed with a distorted wave approximation. Absolute recombination rate coefficients of B-like C, B-like Ne and Be-like F ions are obtained for the first time with high energy resolution from storage ring measurements. The experimental results are compared with the intermediate coupling AUTOSTRUCTURE calculations. Plasma rate coefficients of each of these ions are obtained by convoluting the energy dependent recombination spectra with a Maxwell-Boltzmann energy distribution in the temperature range of 103-106 K. The resulting plasma rate coefficients are presented and compared with the calculated data available in literature.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Accepted. Paper 5: Accepted. Paper 6: Manuscript. Paper 7: Manuscript.

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34

Zhao, Qin. "Development of ion mobility mass spectrometry coupled with ion/ion reactions instrumentation and applications for protein analysis /." [Ames, Iowa : Iowa State University], 2009.

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35

Hornsey, Richard Ian. "Factors affecting ion energy distributions in liquid metal ion sources." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236154.

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36

Papadopoulos, S. "Atomic and cluster ion emission from liquid metal ion sources." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375310.

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37

Scrivens, R. M. "Extraction of an ion beam from a laser ion source." Thesis, Swansea University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638785.

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The CERN Laser Ion Source (LIS) aims to provide a short pulse (5 μs), high current ( 10mA) and high charge state heavy ion beam (Pb²⁵⁺) for acceleration by a LINAC and injection into the Proton Synchrotron Booster (PSB). The laser beam time profile was measured using detectors with time response of the order of 1 ns. Cross correlating of the laser pulse form and the ion beam current one fails to find any significant relation. The laser spatial profile was measured in the focal plane by a Spiricon pyroelectric camera in conjunction with a long focal length lens. In the Master Oscillator and Power Amplifier laser configuration, the beam was found to be astigmatic and exhibit a large pointing instability. The free-running laser produced a beam in good agreement with the simulation of beam propagation along the 30 m path extension and was also astigmatic. As for the time profile, no firm correlation of the laser spatial profile fluctuation and the ion beam instability could be found. Within the framework of this thesis, a critical study has been performed on whether shot-to-shot instabilities are being caused by fluctuation in the laser beam parameters (time profile, spatial distribution and energy) as well as the extraction of the ions from the expanded laser plasma to form an ion beam. In addition, a technique for the calculation of absolute ion numbers was derived. The extraction of the ions from the laser ion source plasma was experimentally studied using Faraday cup collectors, and a compact single shot emittance measurement system. The extraction of the ions was found to be correctly modelled by the Child-Langmuir equations for charge extraction, with some modification necessary to account for the initial significant ion velocity (10⁵ ms^-1) found after plasma expansion. The equivalent proton perveance applicable to the extraction geometry used, was found by systemic measurements of the ion transmission to a Faraday cup as a function of the applied source voltage. Absolute ion numbers were calculated from measurements using an electrostatic ion analyser and a Faraday cup ion collector. From these measurements it was possible to deduce the transmission losses through the Low Energy Beam transport line between the LIS and an RFQ; they were found to be as high as 80%. In summary, the measurements detailed here allow the prediction of the source parameters required for extraction of a higher current, higher charge state beam required for a final LIS implementation capable of supplying the ion beam for the Large Hadron Collider (LHC). In addition, simulations of the beam extraction using a time dependent macro-particle and static ray-tracing software package are described which provide a reasonably good modelling of the beam extraction.

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38

Scott, Graham Bruce Ian. "Experimental studies of astrochemical ion-atom and ion-molecule reactions." Thesis, University of Canterbury. Chemistry, 1997. http://hdl.handle.net/10092/7813.

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Data is presented for a number of ion-molecule and ion-atom reactions of likely relevance to the chemistry of interstellar clouds and planetary atmospheres. The measurements were made using a Selected Ion Flow Tube, (SIFT), operating at ambient temperatures, (300 ± 5 K), and at pressures between 0.30 - 0.35 Torr. The reactivity of two C₃H₃0+ isomers, namely protonated propynal, (HC=C-CHOH⁺), and the association product of C₂H₃⁺ with CO, (C₂H₃.CO), were characterised in laboratory experiments. These measurements bracket the proton affinity of propynal between 759 and 736 kJ mol⁻¹. The proton affinity of propadienone is similarly constrained between 896 and 868 kJ mol⁻¹. In a complementary investigation, the C₃H₃0⁺ potential surface was mapped using ab-initio calculations at the G2 level of theory. This combined experimental/theoretical study demonstrates that the condensation product between C₂H₃⁺ and CO is C₂-protonated propadienone, (H₂C=CH-C=O). Consequently, this finding indicates that propynal is not synthesised in the interstellar medium via the reaction of C2H3 + with carbon monoxide. The reactions between twenty-eight cations and molecular and atomic hydrogen were examined in a series of laboratory experiments. Most hydrocarbon cations react with H atoms by termolecular association or, alternatively, H atom transfer routes. In contrast, only unsaturated hydrocarbon cations tend to react with H₂ via H atom abstraction processes. There are fewer clear trends evident in the reactions between non-hydrocarbon ions and H atoms. If exothermic, H atom abstraction is almost always observed during reactions between non-hydrocarbon cations and H₂. Molecular and atomic hydrogen are both extremely plentiful in dense and diffuse interstellar clouds and these processes are therefore particularly relevant to the chemistry occurring within these objects. Results are presented for the reaction of approximately thirty cations with molecular and atomic nitrogen. Most ions are unreactive with N₂, however atomic nitrogen is a more reactive neutral species. Small hydrocarbon cations react with N atoms by forming C-N bonds and eliminating H or H₂, while larger CmHn⁺ species react with this neutral by forming HCN and a fragment hydrocarbon ion. In general there are no obvious patterns to the reactivity of non-hydrocarbon cations with atomic nitrogen. These processes are pertinent both to interstellar chemistry and the aeronomy of nitrogenous planetary atmospheres. The crucial reaction between H3 + and N has been measured for the first time in the laboratory and found to be rapid, (k= 4.5 x 10⁻¹⁰cm³). This result offers an alternative, (and possibly more facile), synthetic route to ammonia in interstellar clouds. Data is reported for the reaction of nineteen cations with O atoms, O₂ and NO. Small and medium sized hydrocarbon cations react with O atoms forming CmHnO⁺ ions and an H or H₂ fragment, whilst larger CmHn⁺ ions often react by C atom transfer forming CO and a smaller hydrocarbon ion. Most non-hydrocarbon cations examined were unreactive with atomic oxygen. Molecular oxygen is relatively unreactive with most ionic species, however many ions react with NO by charge transfer and/or termolecular association pathways. Nitric oxide, O₂ and O atoms are all present to varying degrees in interstellar clouds, hence the measurements presented here are applicable to the chemistry of these objects. A number of preliminary experiments between ions and atomic carbon are detailed. The techniques for generating C atoms are described. The research described in this thesis is pertinent to the many environments in which plasmas occur.

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39

Lambrecht, Alexander [Verfasser], and Tobias [Akademischer Betreuer] Schätz. "Optical ion trapping with regard to ultracold atom-ion experiments." Freiburg : Universität, 2017. http://d-nb.info/1136567089/34.

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40

Murrell, Jason. "Some studies in ion/molecule reactions on ion trapping instruments." Thesis, University of Kent, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319223.

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41

Bahaffi, Saleh Omar Saeed. "An investigation of ion-exchangers for ion chromatography of anions." Thesis, University of Kent, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328170.

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42

Franklin, A. M. "Computational applications and ion behaviour in ion trap mass spectrometer." Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294313.

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43

Pearson, C. H. G. "New ion exchange resins for ion chromatography applied to anions." Thesis, University of Kent, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372771.

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44

Orrman-Rossiter, Kevin G. "Ion scattering analysis of low energy ion bombarded GaAS(001)." Thesis, University of Salford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327940.

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45

Holden, Nicola Kathleen. "Atmospheric ion measurements using novel high resolution ion mobility spectrometers." Thesis, University of the West of England, Bristol, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288184.

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46

Gallen, Niall Anthony. "Ion implantation waveguide formation in transition metal ion doped insulators." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310665.

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47

Dobie, Paul J. "Microwave excitation of argon ion and helium-krypton ion lasers." Thesis, University of St Andrews, 1989. http://hdl.handle.net/10023/14163.

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Pulsed microwave excitation of noble gas ion lasers at frequencies between 3 and 17 GHz is investigated. The advantages of using microwaves instead of conventional DC sources to pump a laser are explained. These include the lower electrode and discharge tube wear due to the oscillating nature of a microwave electric field. The propagation of microwave radiation in an ionised gas is examined. At the frequencies used, the skin depth of an Argon ion laser discharge is shown to be approximately 1 mm, indicating good microwave power absorption. The dependence of the microwave power absorption on the frequency is shown to be weak. Microwave transmission at a dielectric/gas-discharge boundary, similar to those in the laser coupling structures used, is found to be around 1% of the incident power. It is suggested that for maximum laser efficiency, microwave power should be introduced directly into the gas discharge. Two microwave coupling structure designs for supplying microwave power to the laser discharges are described. The first of these, a waveguide coupler device based on the 3dB branch guide coupler, produces a transverse electric field across the laser tube. The procedure used to design a branch guide coupler using a Chebyshev impedance taper and T- junction discontinuity corrections is outlined, and a description of the entire laser coupling structure is given. The second design comprises a helix wrapped round the laser tube and produces an axial electric field. The electric field distribution around a helix is calculated as a function of helix parameters and the effects of surrounding objects are considered. The best helix dimensions are found for optimum laser operation. The characteristics of conventional Argon ion and Helium-Krypton ion lasers are given. No significant differences between conventional noble gas ion lasers and the microwave excited lasers reported here are observed. At the input powers used (~100 kW peak, 1 uS pulses, 1000 pps), 100 mW, 1 uS and 30 mW, 5 uS laser pulses are observed from Argon and Helium-Krypton gas mixtures, respectively. The transverse and axially excited lasers perform equally well.

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48

Pollum, Laura L. "Digital ion trap mass spectrometry for cold ion-molecule chemistry." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:18c6451d-d247-4384-9257-f8864e038343.

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A promising new approach for studying cold ion-molecule chemical reactions is the combination of laser- or sympathetically-cooled trapped ions and slow-moving molecules from a cold molecule source, such as a quadrupole velocity selector or a Stark decelerator. Previous reaction studies using trapped atomic ions and slow molecules from a quadrupole velocity selector were able to reach average collision energies as low as 1 K. However, the guided molecules had an approximately room temperature rotational energy distribution, so the reactions studied were not truly cold. Thus, a new molecular source for producing translationally and rotationally cold molecules utilizing buffer gas cooling and quadrupole velocity selection was constructed by K. Twyman and characterized for use in cold reaction studies. This new source of cold molecules is referred to as the buffer gas guide. A new ion trap has been designed and built for use with the existing buffer gas guide. The new ion trap apparatus is compact and mechanically compatible with this new guide. It uses a linear Paul ion trap with cylindrical electrodes to trap ions. Two optical axes (one axial and one radial) enable efficient cooling of small ion crystals. A field-free time-of-flight tube and ion detection assembly are also incorporated into the apparatus. A new technique for determining the mass and quantity of trapped ions has also been developed, termed digital ion trap mass spectrometry. The new technique uses a digital RF waveform to trap ions before ejecting the ions radially from the trap using an ejection pulse applied to the trap electrodes. The ions are then detected after free flight along a time-of-flight tube. This technique was characterized by ejecting crystals of various sizes and compositions: Ca⁺ only, Ca⁺/CaF⁺, Ca⁺/CaOH⁺/CaOD⁺, and Ca⁺/NH⁺₃ /NH⁺₄ /H₃O⁺. A linear relationship between the number of ions ejected (determined by comparing experimental and simulated crystal images) and the integral of the time-of-flight peak was observed for Ca⁺ and Ca⁺/CaF⁺. All mass peaks were resolved. Simulations of the trapped ions and their trajectories through the time-of-flight tube were also performed, and excellent agreement between the simulated and experimental mass resolution was observed. Progress towards combining the buffer gas guide with the previously independent ion trap is also presented. It is anticipated that the combined buffer gas guide ion trap apparatus will enable the study of ion-molecule reactions at low temperatures with translationally and rotationally cold molecules. It is anticipated that the new digital ion trap mass spectrometry technique will simplify the study of reactions when multiple product ions whose masses are separated by only 1 AMU are formed. A new ion trap has been designed and built for use with the existing buffer gas guide. The new ion trap apparatus is compact and mechanically compatible with this new guide. It uses a linear Paul ion trap with cylindrical electrodes to trap ions. Two optical axes (one axial and one radial) enable efficient cooling of small ion crystals. A field-free time-of-flight tube and ion detection assembly are also incorporated into the apparatus. A new technique for determining the mass and quantity of trapped ions has also been developed, termed digital ion trap mass spectrometry. The new technique uses a digital RF waveform to trap ions before ejecting the ions radially from the trap using an ejection pulse applied to the trap electrodes. The ions are then detected after free flight along a time-of-flight tube. This technique was characterized by ejecting crystals of various sizes and compositions: Ca+ only, Ca+/CaF+, Ca+/CaOH+/CaOD+, and Ca+/NH+3/NH+4/H3O+. A linear relationship between the number of ions ejected (determined by comparing experimental and simulated crystal images) and the integral of the time-of-flight peak was observed for Ca+ and Ca+/CaF+. All mass peaks were resolved. Simulations of the trapped ions and their trajectories through the time-of-flight tube were also performed, and excellent agreement between the simulated and experimental mass resolution was observed. Progress towards combining the buffer gas guide with the previously independent ion trap is also presented. It is anticipated that the combined buffer gas guide ion trap apparatus will enable the study of ion-molecule reactions at low temperatures with translationally and rotationally cold molecules. It is anticipated that the new digital ion trap mass spectrometry technique will simplify the study of reactions when multiple product ions whose masses are separated by only 1 AMU are formed.

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49

Steele, Adam V. "Barium ion cavity qed and triply ionized thorium ion trapping." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26530.

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Thesis (Ph.D)--Physics, Georgia Institute of Technology, 2009.
Committee Chair: Michael Chapman; Committee Member: Alex Kuzmich; Committee Member: Brian Kennedy; Committee Member: Chandra Raman; Committee Member: Kenneth Brown. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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50

Miller, Catherine Elizabeth. "Characterization of ion Cluster fragmentation in ionic liquid ion sources." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122372.

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This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 273-281).
Ion electrospray propulsion is a cutting-edge micropropulsion technology that could revolutionize the capabilities of microsatellites. Ion electrospray thrusters could also be used on large spacecraft for precision attitude control applications such as gravity wave detection and exoplanet imaging. Novel room temperature molten salts, called ionic liquids, are used as propellant, which are composed purely of positive and negative molecular ions. When exposed to strong electric fields, ions and metastable clusters of ions are evaporated from the bulk liquid surface. The free ions and ion clusters can be accelerated to high velocities, producing thrust at high specific impulse. The performance of ion electrospray thrusters is affected by the composition of the ion beam and the amount of ion clusters that break apart during the acceleration phase. To improve thruster performance, a better understanding of the fundamental physics of ion evaporation and cluster break-up is needed.
The break-up of ion clusters, also called fragmentation, is not a well understood phenomenon. It has been observed in past experiments, but the rates of break-up have not been measured. The focus of this work is to experimentally investigate fragmentation more deeply than ever before. To accomplish this, a specialized instrumentation suite has been designed, built, and tested to measure fragmentation characteristics in unprecedented detail. A full-beam, spherical geometry retarding potential analyzer is used to measure the rates of fragmentation of ion clusters both outside the thruster and within the acceleration region for the first time. A narrow-beam, high time-resolution time of flight mass spectrometer is used to measure the beam composition. Single emitters based on resorcinol formaldehyde carbon xerogels were used as ion sources. Four ionic liquids spanning a wide range of liquid properties were characterized: EMI-FAP, EMI-Im, EMI-BF4, and BMI-I.
Analytical models were also developed to enhance the interpretation of the experimental results. The experimental measurements show that the amount of fragmentation increases with distance from the thruster and follows a constant rate equation. The mean lifetimes of ion clusters outside of the thruster range from 1-6 [mu]s, indicating that these clusters are quite unstable. It is observed that the fragmentation throughout most of the acceleration region is linear with respect to electric potential, which can be understood using analytical models. Rapid fragmentation likely occurs immediately after evaporation due to the strong electric fields near the emission site, which has significant implications for thruster performance. It is also observed that clusters of complex molecular ions which consist of many atoms tend to be the most stable. The initial temperature of ion clusters, which range from 520 K - 790 K, were estimated using analytical methods.
The effect of liquid temperature on the rates of fragmentation was also investigated. In conclusion, the work in this thesis provides a greatly enhanced understanding of ion cluster fragmentation, particularly how it is affected by ionic liquid properties, liquid temperature, and electric fields.
This research was supported by a NASA Space Technology Research Fellowship
by Catherine Elizabeth Miller.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics

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