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Propellant Utilization In Hall Thrusters
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Book Synopsis Propellant Utilization in Hall Thrusters by : Y. Raitses
Download or read book Propellant Utilization in Hall Thrusters written by Y. Raitses and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fundamentals of Electric Propulsion by : Dan M. Goebel
Download or read book Fundamentals of Electric Propulsion written by Dan M. Goebel and published by John Wiley & Sons. This book was released on 2008-12-22 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout most of the twentieth century, electric propulsion was considered the technology of the future. Now, the future has arrived. This important new book explains the fundamentals of electric propulsion for spacecraft and describes in detail the physics and characteristics of the two major electric thrusters in use today, ion and Hall thrusters. The authors provide an introduction to plasma physics in order to allow readers to understand the models and derivations used in determining electric thruster performance. They then go on to present detailed explanations of: Thruster principles Ion thruster plasma generators and accelerator grids Hollow cathodes Hall thrusters Ion and Hall thruster plumes Flight ion and Hall thrusters Based largely on research and development performed at the Jet Propulsion Laboratory (JPL) and complemented with scores of tables, figures, homework problems, and references, Fundamentals of Electric Propulsion: Ion and Hall Thrusters is an indispensable textbook for advanced undergraduate and graduate students who are preparing to enter the aerospace industry. It also serves as an equally valuable resource for professional engineers already at work in the field.
Book Synopsis Ion-thruster Propellant Utilization by : Harold R. Kaufman
Download or read book Ion-thruster Propellant Utilization written by Harold R. Kaufman and published by . This book was released on 1971 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The evaluation and understanding of maximum propellant utilization, with mercury used as the propellant are presented. The primary-electron region in the ion chamber of a bombardment thruster is analyzed at maximum utilization. The results of this analysis, as well as experimental data from a range of ion-chamber configurations, show a nearly constant loss rate for unionized propellant at maximum utilization over a wide range of total propellant flow rate. The discharge loss level of 1000 eV/ion was used as a definition of maximum utilization, but the exact level of this definition has no effect on the qualitative results and little effect on the quantitative results. There are obvious design applications for the results of this investigation, but the results are particularly significant whenever efficient throttled operation is required.
Book Synopsis Thrust Efficiency, Energy Efficiency, and the Role of VDF in Hall Thruster Performance Analysis (Postprint). by :
Download or read book Thrust Efficiency, Energy Efficiency, and the Role of VDF in Hall Thruster Performance Analysis (Postprint). written by and published by . This book was released on 2007 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rocket power efficiency equation was written to explicitly account for the effect of the velocity distribution function (VDF) of the propellant jet on the conversion of anode electrical energy to jet kinetic energy. This enabled a mathematically rigorous distinction to be made between thrust efficiency and energy efficiency. In this approach anode thrust efficiency, the commonly reported figure of merit for Hall thrusters, is the product of three utilization efficiencies: (1) propellant utilization efficiency, (2) voltage utilization efficiency, and (3) current utilization efficiency, which are less than unity under all real operating conditions. Unit propellant utilization is characterized by 100 percent ionization to a single ionic species whose thrust vectors are all directed along the same thrust axis. Anode voltage utilization efficiency is unity when ion species are created at the anode and accelerated through the entire anode potential. Current utilization efficiency is the fraction of cathode electron flow utilized in neutralization of accelerated positive ions. It can never be unity because a portion of the electron flow must be recycled back to the anode to provide energy to ionize neutral propellant. The architecture of the efficiency analysis is such that energy efficiency becomes naturally expressed as a product of voltage and current utilization efficiencies, and is rigorously separated from propellant utilization efficiency. Thus, thrust efficiency is the product of propellant utilization efficiency and energy efficiency. The methodology is applied to analysis of data from systematic low and high power (0.2 to 50 kW) Hall thruster performance studies published in the open literature. The cited data includes measurement of thrust, propellant mass flow rate, anode voltage, and anode current coupled with various electrical and optical diagnosis that provide information about the VDF and thermodynamic state of the propellant jet.
Book Synopsis Magnetic Shielding Topology Applied to Low Power Hall Thrusters by : Lou Grimaud
Download or read book Magnetic Shielding Topology Applied to Low Power Hall Thrusters written by Lou Grimaud and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hall thrusters are one of the most used rocket electric propulsion technology. They combine moderate specific impulse with high thrust to power ratio which makes them ideal for a wide range of practical commercial and scientific applications. One of their limitations is the erosion of the thruster walls which reduces their lifespan.The magnetic shielding topology is a proposed solution to prolong the lifespan. It is implemented on a small200W Hall thruster.In this thesis the scaling of classical unshielded Hall thrusters down to 200 and 100W is discussed. A 200W low power magnetically shielded Hall thruster is compared with an identically sized unshielded one. The ion behavior inside the thruster is measured and significant differences are found across the discharge channel.Both thrusters are tested with classical BN-SiO2 and graphite walls. The magnetically shielded thruster is not sensitive to the material change while the discharge current increase by 25% in the unshielded one. The result is a maximum efficiency of 38% for boron nitride in the unshielded thruster but only 31% with graphite.The shielded thruster achieves a significantly lower efficiency with only 25% efficiency with both materials.Analysis of the experimental results as well as simulations of the thrusters reveal that the performance difference is mostly caused by low propellant utilization. This low propellant utilization comes from the fact that the ionization region doesn't cover all of the discharge channel. A new magnetically shielded thruster is designed to solve this issue.
Book Synopsis An Evaluation of Krypton Propellant in Hall Thrusters by : Jesse Allen Linnell
Download or read book An Evaluation of Krypton Propellant in Hall Thrusters written by Jesse Allen Linnell and published by . This book was released on 2006 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Performance Evaluation of the SPT-140 by :
Download or read book Performance Evaluation of the SPT-140 written by and published by . This book was released on 1997 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Ion Propulsion for Space Flight by : Ernst Stuhlinger
Download or read book Ion Propulsion for Space Flight written by Ernst Stuhlinger and published by . This book was released on 1964 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Standardization of Hall Thruster Efficiency Analysis: Methodology and Historical Perspective by :
Download or read book Standardization of Hall Thruster Efficiency Analysis: Methodology and Historical Perspective written by and published by . This book was released on 2008 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rocket power efficiency equation was analytically decomposed to explicitly account for the effects of energy conversion losses, plume divergence, and the velocity distribution function of the propellant jet. In this approach, thruster efficiency is the product of (1) energy efficiency and (2) propellant utilization efficiency. Energy efficiency is expressed as the product of voltage utilization efficiency and current utilization efficiency, and incorporates losses from Joule heating, radiation, and ionization processes. Energy efficiency contains no information about the vector properties of the jet. Propellant utilization efficiency incorporates losses from plume divergence and ion jet composition, and is unity for 100% ionization to a single ion species whose velocity vectors are directed along the thrust axis. The efficiency architecture is derived from first principles and is applicable to all propulsion employing electrostatic acceleration, including Hall thrusters and ion engines. The analysis is compared to past methodologies and is illustrated with thrust and far-field plume measurements of a laboratory Hall thruster.
Book Synopsis A Plume Comparison of Xenon and Krypton Propellant on a 600 W Hall Thruster by :
Download or read book A Plume Comparison of Xenon and Krypton Propellant on a 600 W Hall Thruster written by and published by . This book was released on 2009 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was conducted to compare variations in the plume of a 600 W Hall effect thruster operating on xenon and krypton propellants. Both a guarded Faraday probe and a retarding potential analyzer were used to measure plume properties for various thruster operating conditions. Discharge current data was also measured in the time domain using an oscilloscope and in the frequency domain using a signal analyzer for all tested operating conditions. Operating conditions were chosen to provide a comparison of the effects of radial magnetic field strength for both propellants. For each xenon propellant operating condition, two krypton propellant operating conditions were tested. One condition matched volumetric flow rate and the other condition matched anode power by increasing the anode flow rate. The plume data were analyzed to calculate various components of the energy and propellant utilization efficiencies as defined in Ref. 1. Faraday probe data were used to calculate the divergence and beam current utilization efficiencies. Voltage utilization efficiency was calculated using data from the retarding potential analyzer. Compared with xenon, krypton divergence efficiency is approximately 15-20% lower and its current utilization efficiency is 5-10% lower. Differences between voltage utilization efficiency for xenon and krypton were small. Anode current oscillation magnitude was lower for krypton propellant.
Download or read book Propulsion written by Kazuo Matsuuchi and published by BoD – Books on Demand. This book was released on 2021-12-15 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost all animals move around frequently in space. Their aim is to walk and fly in search of food or to propagate their species. Thus, changing positions is important for creatures’ survival and maintaining the environment. As such, this book examines movement with a focus on force and propulsion. Chapters cover topics including rocket engines, electric propulsion, mechanisms of force, and more.
Book Synopsis Ion-thruster Propellant Utilization by : Harold Richard Kaufman
Download or read book Ion-thruster Propellant Utilization written by Harold Richard Kaufman and published by . This book was released on 1971 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Physics of Electric Propulsion by : Robert G. Jahn
Download or read book Physics of Electric Propulsion written by Robert G. Jahn and published by Courier Corporation. This book was released on 2006-05-26 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Literaturangaben. - Originally published: New York, NY : McGraw-Hill, 1968
Book Synopsis Plasma Oscillations and Associated Electron Transport Within Hall Thrusters by : Aaron Kombai Knoll
Download or read book Plasma Oscillations and Associated Electron Transport Within Hall Thrusters written by Aaron Kombai Knoll and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hall thruster is a type of plasma propulsion system for space vehicle applications. The thrust produced by this device is derived from the momentum of ions, which are accelerated to high exit velocities by the action of an electric field sustained within the plasma. The advantage of the Hall thruster compared to conventional chemical rocket propulsion is a significantly higher exhaust velocity, which leads to better utilization of propellant mass. Since the early days of Hall thruster research, experiments have suggested that the mobility of electrons along the axis of the thruster, perpendicular to an imposed magnetic field, is higher than can be explained by classical collision transfer processes alone. A lack of understanding regarding the mechanism for this enhanced mobility has proved a significant challenge toward the development of reliable simulations capable of predicting the performance of these devices. This thesis examines the role of high frequency plasma oscillations on the electron mobility using a combination of experimental studies on a laboratory Hall thruster, and numerical simulations capable of capturing these oscillations and quantifying their impact on the electron mobility. Two high frequency oscillations were consistently observed in the experiments: a 10MHz mode which appeared strongest in the vicinity of the anode, and a 4.5MHz mode which was strongest in the mid-channel region of the thruster. These were relatively low wave number (long wavelength) oscillations: approximately 6cm for the 4.5MHz oscillation and 3cm for the 10MHz oscillation. The angle of these waves varied considerably depending on the operating conditions of the thruster. They were found to be closely aligned to the axis of the thruster for experiments conducted with Xenon propellant, and were aligned with the circumference of the thruster (in the direction of electron drift) for experiments conducted with Krypton. A Hall thruster simulation, formulated in the axial-azimuthal coordinates of the thruster, was able to capture high frequency oscillations in reasonable agreement with experimental findings: 13MHz near the anode and 5MHz in the mid-channel region of the thruster for 160V discharge conditions. The simulation results demonstrated the crucial role of these oscillations in regulating the electron transport. In the vicinity of these oscillations the electron mobility was increased by a factor of five or more. The central finding of this thesis is that high frequency oscillations in the range 1 - 50MHz can account for the observed discrepancy between classical and experimental electron mobility in the Hall thruster.
Book Synopsis A Review of United States Air Force and Department of Defense Aerospace Propulsion Needs by : National Research Council
Download or read book A Review of United States Air Force and Department of Defense Aerospace Propulsion Needs written by National Research Council and published by National Academies Press. This book was released on 2007-01-14 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rocket and air-breathing propulsion systems are the foundation on which planning for future aerospace systems rests. A Review of United States Air Force and Department of Defense Aerospace Propulsion Needs assesses the existing technical base in these areas and examines the future Air Force capabilities the base will be expected to support. This report also defines gaps and recommends where future warfighter capabilities not yet fully defined could be met by current science and technology development plans.
Book Synopsis Study of Energy Loss Mechanisms in the BPT-4000 Hall Thruster by :
Download or read book Study of Energy Loss Mechanisms in the BPT-4000 Hall Thruster written by and published by . This book was released on 2003 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerojet has developed a high performance multi-mode flightweight Hall thruster for orbit raising and stationkeeping on geo-synchronous satellites. In order to further understand and improve upon the performance of this state of the art Hall thruster and other next generation thrusters being planned, a detailed study of the energy loss mechanisms has been conducted. Calculations of each loss mechanism have been performed using experimental data as input. A comparison of the relative magnitude of each loss mechanism shows that energy deposition in the anode and radial kinetic energy are the dominant losses in this thruster followed by energy deposition in the insulator rings. The calculations also show that the propellant utilization efficiency is only 70% but the voltage losses are minimal. These results indicate potential for improved performance of this and other next generation thrusters if the electron- neutral collision frequency can be increased and the ion beam acceleration focused with improved magnetic field and anode designs.
Book Synopsis Development and Characterization of High-efficiency, High-specific Impulse Xenon Hall Thrusters by : Richard Robert Hofer
Download or read book Development and Characterization of High-efficiency, High-specific Impulse Xenon Hall Thrusters written by Richard Robert Hofer and published by . This book was released on 2004 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: