Fundamentals of Electric Propulsion: Ion and Hall Thrusters

PDF Publication Title:

Fundamentals of Electric Propulsion: Ion and Hall Thrusters ( fundamentals-electric-propulsion-ion-and-hall-thrusters )

Previous Page View | Next Page View | Return to Search List

Text from PDF Page: 288

Hollow Cathodes 277 f =1exp n wall , (6.5-11) noCEX and wall is the average time between collisions with the wall for a neutral particle. This effective heating mechanism by charge exchange has been observed in experiments where the neutral temperatures are higher than the orifice wall temperatures. Combining the electron and ion momentum equations [Eqs. (6.4-30) and (6.4-31)] to eliminate the electric field term gives an expression for the particle motion in terms of the ambipolar diffusion coefficient and the ion and electron mobilities: n(v v )=D n+ μi Je . (6.5-12) io azμee The ambipolar diffusion coefficient for this case is given by Eq. (6.4-4). In the orifice, the radial drift velocity will often exceed the ion thermal speed due to the radial potential gradient, so the ion scattering velocity must be approximated by v = v2+(vv)2+v, (6.5-13) scat th i o r where vr is the radial ion velocity found from Eq. (6.4-7). The continuity equations in the orifice [Eqs. (6.5-5) through (6.5-7)] are solved using the electron energy equation, Eq. (6.4-28), in the cylindrical orifice, which produces ion density and plasma potential profiles in the orifice region. The first result from this work is that a double sheath postulated in the orifice region [36] is not observed for xenon ion thruster cathodes. There is a potential change through the orifice, but this results from resistive effects in the orifice channel due to electron-ion and electron-neutral collisions. As an example, Fig. 6-20 shows a plot of the neutral and plasma densities along the axis of an NSTAR neutralizer cathode orifice operating at the TH15 power point, producing 3.76 A of current with a xenon gas flow rate of 3.5 sccm [37]. The peak plasma density occurs in the cylindrical section of the orifice, and the density falls though the chamfered region due to the neutral gas density decrease. It should be noted that the peak plasma density predicted by the 1-D model in the orifice is in reasonable agreement with the 0-D model results shown above that used the average neutral density and temperature along the length of the orifice. Reasonably accurate results can be obtained using simple 0-D models to illustrate the driving physics in this region.

PDF Image | Fundamentals of Electric Propulsion: Ion and Hall Thrusters

PDF Search Title:

Fundamentals of Electric Propulsion: Ion and Hall Thrusters

Original File Name Searched:

Goebel__cmprsd_opt.pdf

DIY 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)