PDF Publication Title:
Text from PDF Page: 375
Hall Thrusters 365 Dielectric-wall Hall thrusters are often described in terms of an ionization zone upstream of the exit plane and an acceleration zone in the region of the exit plane. TAL thrusters have a similar ionization region near the magnetic field maximum, which is now closer to the anode because the magnetic field gradient is greater. The TAL acceleration zone is described as being a layer close to the anode [1,3] that can extend outside of the thruster [48]. The higher electron temperatures associated with TAL thrusters support higher electric fields in the quasi-neutral plasma, which compresses these zones relative to dielectric-wall thrusters. In addition, the metallic walls and higher electric fields are conducive to multiple acceleration stages, which can improve thruster performance and produce higher Isp than a conventional single-stage TAL thruster [1,51]. Multiple-stage dielectric-wall Hall thrusters that operate at high Isp have also been investigated (see [17] and the references cited therein). Finally, the difference between dielectric-wall Hall thrusters and TAL thrusters is sometimes attributed to the secondary electron coefficients of the different wall materials. The above discussion shows that this is not the dominant difference. Instead, the proximity of the TAL anode electrode to the high temperature plasma region and the thruster exit plane is what changes the electric field profile, power deposition, and sputtering characteristics as compared to the dielectric-wall Hall thruster. 7.4 Channel Physics and Numerical Modeling As discussed in the previous sections, the detailed physics determining Hall thruster performance is not well understood. Specifically, the electron distribution function in the exit region, the mechanisms responsible for electron transport across the magnetic field, and the role of oscillations on the particle transport and plasma conditions need to be determined. A considerable effort has been made to develop fluid, kinetic, hybrid, and particle-in-cell (PIC) models to predict and explain the performance and effects observed in Hall thrusters. Hirakawa and Arakawa developed [52] a two-dimensional (2-D) particle-in-cell model where anomalous electron diffusion was introduced by using oscillating azimuthal electric fields. Boeuf and Garrigues developed a one-dimensional (1-D) hybrid model [53] in which the electrons were treated as a fluid and the ions were described by a collisionless Vlasov (kinetic) equation. Similar fluid and hybrid models have been developed by other authors [54–56] using various techniques to determine the ion transport, such as Monte-Carlo simulation, Boltzman equation solutions, and “ion free-fall” (essentially a Bohm current solution) to the boundaries. The most widely used code, HPHall, is a 2-D, transient hybrid model originated by Fife and Martinez-Sanchez [30] that has been recently extended with an improved sheath model [41,42,57] and a model of channel erosion [58,59].PDF Image | Fundamentals of Electric Propulsion: Ion and Hall Thrusters
PDF Search Title:
Fundamentals of Electric Propulsion: Ion and Hall ThrustersOriginal File Name Searched:
Goebel__cmprsd_opt.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)