Download or read book Electric Field Determination and Magnetic Topology Optimization in Hall Thrusters written by Julien Vaudolon and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electric propulsion is facing new challenges. Recently, the launch of "all-electric" satellites has marked the debut of a new era. Going all-electric now appears as an interesting alternative to conventional systems for telecom operators. A laser spectroscopy technique was used during this research to investigate the ion velocity distribution dynamics. The different methods for determining the electric field in Hall thrusters were exposed. Two unstable ion regimes were identified and examined. Measurement uncertainties using electrostatic probes were assessed. Planar probed have been designed and tested. A thorough investigation of the influence of the magnetic field parameters on the performance of Hall thrusters was performed. The wall-less Hall thruster design was presented, and preliminary experiments have revealed its interest for the electric propulsion community.

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.

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.

Download or read book The Influence of Current Density and Magnetic Field Topography in Optimizing the Performance Divergence and Plasma Oscillations of High Specific Impulse Hall Thrusters written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies of xenon Hall thrusters have shown peak efficiencies at specific impulses of less than 3000 s. This was a consequence of modern Hall thruster magnetic field topographies, which have been optimized for 300 V discharges. On-going research at the NASA Glenn Research Center is investigating this behavior and methods to enhance thruster performance. To conduct these studies, a laboratory model Hall thruster that uses a pair of trim coils to tailor the magnetic field topography for high specific impulse operation has been developed. The thruster-the NASA-173Mv2 was tested to determine how current density and magnetic field topography affect performance, divergence, and plasma oscillations at voltages up to 1000 V. Test results showed there was a minimum current density and optimum magnetic field topography at which efficiency monotonically increased with voltage. At 1000 V, 10 milligrams per second the total specific impulse was 3390 s and the total efficiency was 60.8%. Plume divergence decreased at 400-1000 V, but increased at 300-400 V as the result of plasma oscillations. The dominant oscillation frequency steadily increased with voltage, from 14.5 kHz at 300 V, to 22 kHz at 1000 V. An additional oscillatory mode in the 80-90 kHz frequency range began to appear above 500 V. The use of trim coils to modify the magnetic field improved performance while decreasing plume divergence and the frequency and magnitude of plasma oscillations. Hofer, Richard R. and Jankovsky, Robert S. Glenn Research Center NASA/TM-2003-212605, E-14163, IEPC-2003-142

Download or read book Hall Thruster Electron Mobility Investigation Using Full 3D Monte Carlo Trajectory Simulations preprint written by Darren A. Alman and published by . This book was released on 2007 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Axial electron transport represents a loss in efficiency for crossed field devices, such as Hall-effect thrusters (HETs). Previous experimental and computational investigations have revealed an anomalous axial mobility that cannot be explained with classical theory. This work describes the development of a computational model that calculates electron mobility in HETs using known electric and magnetic fields. Specifically, a full 3D Monte Carlo trajectory simulation code is developed to simulate HET internal electron dynamics."--P. [i].

Download or read book Low Power Magnetically Shielded Hall Thrusters written by Ryan Conversano and published by . This book was released on 2015 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents an investigation of the applicability of magnetic shielding to low-power Hall thrusters as a means to significantly improve operational lifetime. The key life-limiting factors of conventional Hall thrusters, including ion-bombardment sputter erosion of the discharge channel and high-energy electron power deposition to the channel walls, have been investigated extensively for a wide range of thruster scales. As thruster power is reduced to the "miniature" (i.e. sub-500 W) power regime, the increased surface-to-volume ratio of the discharge channel and decreased thruster component sizes promotes increased plasma-wall interactions and susceptibility to overheating, thereby reducing thruster operational lifetime and performance. Although methods for compensating for these issues have been investigated, unshielded miniature Hall thrusters are generally limited to sub-45% anode efficiencies and maximum lifetimes on the order of 1,000 h. A magnetically shielded magnetic field topology aims to maintain a low electron temperature along the channel surfaces and a plasma potential near that of the discharge voltage along the entire surface of the discharge channel along its axial length. These features result in a reduction of the kinetic energy of ions that impact the channel surfaces to near to or below the sputtering threshold, thus preventing significant ion-bombardment erosion of the discharge channel. Improved confinement of high-energy electrons is another byproduct of the field structure, aiding in the reduction of electron power deposition to the channel. Magnetic shielding has been shown to dramatically reduce plasma-wall interactions on 4 - 6 kW Hall thrusters, resulting in significant increases in projected operational lifetimes with minimal effects to thruster performance. In an effort to explore the scalability of magnetic shielding to low-power devices, two magnetically shielded miniature Hall thrusters were designed, fabricated and tested. The performance of the first thruster, called the MaSMi 40, was characterized at an operating condition of 275 V and 325 W. A peak thrust of approximately 13 mN with a specific impulse of approximately 1,100 s at an anode efficiency of approximately 22% were measured at the nominal operating point. Observations of the near exit plasma discharge during operation, and the discharge channel after operation, suggested that the outer channel wall of the thruster was well shielded from ion bombardment while the inner channel wall appeared to be weakly shielded. Further analysis concluded that the MaSMi-40 generated a partially-magnetically shielded field topology. However, the shortcomings of the MaSMi-40's magnetic circuit design were investigated in detail and are now well understood. The second design iteration in the development of a low-power magnetically shielded Hall thruster was the MaSMi-60. Magnetic field measurements confirmed that a symmetric and fully shielded magnetic field topology was generated by this device across a wide range of possible operating conditions. At operating powers of 160 W to nearly 750 W, the key performance metrics of the MaSMi-60 included a measured thrust ranging from approximately 8 mN to over 33 mN with anode specific impulses of up to approximately 1370 s at anode efficiencies of over 28%. Downstream plume measurements identified the primary factors contributing to the low anode efficiency. Visual observations of the discharge plasma and channel walls during and after thruster operation offered strong evidence of magnetic shielding. Erosion rates of the channel were approximated using carbon backsputter measurements; the results suggested a 10x - 100x decrease in wall erosion compared to unshielded Hall thrusters, corresponding to an equal increase in discharge channel lifetime compared to conventional miniature unshielded Hall thrusters. The physics and behaviors of the MaSMi-60's plasma discharge upstream of and in the near-field of the thruster exit plane were investigated using Hall2De, the 2-D axisymmetric code developed at the Jet Propulsion Laboratory for the simulation of the partially ionized plasma in Hall thrusters. Simulations of the MaSMi-60 suggested that the thruster achieved the plasma properties required for effective magnetic shielding, including low electron temperatures and a near-constant plasma potential along the channel walls. This was the final piece of evidence suggesting that magnetic shielding was attained at the miniature scale. The experimentally measured performance of the MaSMi-60 was captured by the Hall2De model, offering physical explanations for the low measured anode efficiency and leading to suggestions for improving the performance in future design iterations.

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

Download or read book The Proceedings of the 2018 Asia Pacific International Symposium on Aerospace Technology APISAT 2018 written by Xinguo Zhang and published by Springer. This book was released on 2019-06-08 with total page 3068 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a compilation of peer-reviewed papers from the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018). The symposium is a common endeavour between the four national aerospace societies in China, Australia, Korea and Japan, namely, the Chinese Society of Aeronautics and Astronautics (CSAA), Royal Aeronautical Society Australian Division (RAeS Australian Division), the Korean Society for Aeronautical and Space Sciences (KSAS) and the Japan Society for Aeronautical and Space Sciences (JSASS). APISAT is an annual event initiated in 2009 to provide an opportunity for researchers and engineers from Asia-Pacific countries to discuss current and future advanced topics in aeronautical and space engineering.

Download or read book Reviews of Plasma Physics written by M. Leontovich and published by Springer. This book was released on 1987-05-01 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Permanent Magnet Motor Technology written by Jacek F. Gieras and published by CRC Press. This book was released on 2009-08-25 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of permanent magnet (PM) motor technology and its impact on electromechanical drives has grown exponentially since the publication of the bestselling second edition. The PM brushless motor market has grown considerably faster than the overall motion control market. This rapid growth makes it essential for electrical and electromechanical engineers and students to stay up-to-date on developments in modern electrical motors and drives, including their control, simulation, and CAD. Reflecting innovations in the development of PM motors for electromechanical drives, Permanent Magnet Motor Technology: Design and Applications, Third Edition demonstrates the construction of PM motor drives and supplies ready-to-implement solutions to common roadblocks along the way. This edition supplies fundamental equations and calculations for determining and evaluating system performance, efficiency, reliability, and cost. It explores modern computer-aided design of PM motors, including the finite element approach, and explains how to select PM motors to meet the specific requirements of electrical drives. The numerous examples, models, and diagrams provided in each chapter facilitate a lucid understanding of motor operations and characteristics. This 3rd edition of a bestselling reference has been thoroughly revised to include: Chapters on high speed motors and micromotors Advances in permanent magnet motor technology Additional numerical examples and illustrations An increased effort to bridge the gap between theory and industrial applications Modified research results The growing global trend toward energy conservation makes it quite possible that the era of the PM brushless motor drive is just around the corner. This reference book will give engineers, researchers, and graduate-level students the comprehensive understanding required to develop the breakthroughs that will push this exciting technology to the forefront.

Download or read book Optimization and Inverse Problems in Electromagnetism written by Marek Rudnicki and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: From 12 to 14 September 2002, the Academy of Humanities and Economics (AHE) hosted the workshop "Optimization and Inverse Problems in Electromagnetism". After this bi-annual event, a large number of papers were assembled and combined in this book. During the workshop recent developments and applications in optimization and inverse methodologies for electromagnetic fields were discussed. The contributions selected for the present volume cover a wide spectrum of inverse and optimal electromagnetic methodologies, ranging from theoretical to practical applications. A number of new optimal and inverse methodologies were proposed. There are contributions related to dedicated software. Optimization and Inverse Problems in Electromagnetism consists of three thematic chapters, covering: -General papers (survey of specific aspects of optimization and inverse problems in electromagnetism), -Methodologies, -Industrial Applications. The book can be useful to students of electrical and electronics engineering, computer science, applied mathematics (PhD level) and to researchers interested in the topic.

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:

Download or read book Electron Cyclotron Resonance Ion Sources and ECR Plasmas written by R Geller and published by Routledge. This book was released on 2018-12-13 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acknowledged as the "founding father" of and world renowned expert on electron cyclotron resonance sources Richard Geller has produced a unique book devoted to the physics and technicalities of electron cyclotron resonance sources. Electron Cyclotron Resonance Ion Sources and ECR Plasmas provides a primer on electron cyclotron phenomena in ion sour

Download or read book Ionized Physical Vapor Deposition written by and published by Academic Press. This book was released on 1999-10-14 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides the first comprehensive look at a pivotal new technology in integrated circuit fabrication. For some time researchers have sought alternate processes for interconnecting the millions of transistors on each chip because conventional physical vapor deposition can no longer meet the specifications of today's complex integrated circuits. Out of this research, ionized physical vapor deposition has emerged as a premier technology for the deposition of thin metal films that form the dense interconnect wiring on state-of-the-art microprocessors and memory chips. For the first time, the most recent developments in thin film deposition using ionized physical vapor deposition (I-PVD) are presented in a single coherent source. Readers will find detailed descriptions of relevant plasma source technology, specific deposition systems, and process recipes. The tools and processes covered include DC hollow cathode magnetrons, RF inductively coupled plasmas, and microwave plasmas that are used for depositing technologically important materials such as copper, tantalum, titanium, TiN, and aluminum. In addition, this volume describes the important physical processes that occur in I-PVD in a simple and concise way. The physical descriptions are followed by experimentally-verified numerical models that provide in-depth insight into the design and operation I-PVD tools. Practicing process engineers, research and development scientists, and students will find that this book's integration of tool design, process development, and fundamental physical models make it an indispensable reference. Key Features: The first comprehensive volume on ionized physical vapor deposition Combines tool design, process development, and fundamental physical understanding to form a complete picture of I-PVD Emphasizes practical applications in the area of IC fabrication and interconnect technology Serves as a guide to select the most appropriate technology for any deposition application *This single source saves time and effort by including comprehensive information at one's finger tips *The integration of tool design, process development, and fundamental physics allows the reader to quickly understand all of the issues important to I-PVD *The numerous practical applications assist the working engineer to select and refine thin film processes

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1016 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rocket and Spacecraft Propulsion written by Martin J. L. Turner and published by Springer Science & Business Media. This book was released on 2006-08-29 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: The revised edition of this practical, hands-on book discusses the launch vehicles in use today throughout the world, and includes the latest details on advanced systems being developed, such as electric and nuclear propulsion. The author covers the fundamentals, from the basic principles of rocket propulsion and vehicle dynamics through the theory and practice of liquid and solid propellant motors, to new and future developments. He provides a serious exposition of the principles and practice of rocket propulsion, from the point of view of the user who is not an engineering specialist.

Download or read book Transport property and Mass Spectral Measurements in the Plasma Exhaust Plume of a Hall effect Space Propulsion System written by Lyon Bradley King and published by . This book was released on 1998 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: