Download or read book Electron Temperature Effects on Pulsed Plasma Thruster Plume Expansion written by Nikos A. Gatsonis and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Effects in the Near Field Plume Exhaust of a Micro Pulsed Plasma Thruster written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we present a model of the near field plasma plume of a Pulsed Plasma Thruster (PPT). As a working example we consider a micro-PPT developed at the Air Force Research Laboratory. This is a miniaturized design of the axisymmetric PPT with a thrust in the 10 micro-N range that utilizes Teflon(Trademark(sup Trademark)) as a propellant. The plasma plume is simulated using a hybrid fluid-PIC-DSMC approach. The plasma plume model is combined with Teflon(Trademark) ablation and plasma generation models that provide boundary conditions for the plume. This approach provides a consistent description of the plasma flow from the surface into the near plume. The magnetic field diffusion into the plume region is also considered and plasma acceleration by the electromagnetic mechanism is studied. Teflon(Trademark) ablation and plasma generation analyses show that file Teflon(Trademark) surface temperature and plasma parameters are strongly non-uniform in the radial direction. The plasma density near the propellant surface peaks at about 10(exp 24)/cu m in the middle of the propellant face while the electron temperature peaks at about 4 eV near the electrodes. The plume simulation shows that a dense plasma focus is developed at a few millimeters from the thruster exit plane at the axis. This plasma focus exists during the entire pulse, but the plasma density in the focus decreases from about 2x10(exp 22)/cu m at the beginning of the pulse down to 0.3x10(exp 22)/cu m at 5 microsec. The velocity phase is centered at about 20 km/s in the axial direction. At later stages of the pulse there are two ion populations with positive and negative radial velocity. Electron densities predicted by file plume model are compared with near field measurements using a Herriot Cell technique and very good agreement is obtained.
Download or read book Particle Simulation of Pulsed Plasma Thruster Plumes written by and published by . This book was released on 2002 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final report summarizes the research carried out on the development of numerical approaches for simulating the plumes of pulsed plasma thrusters. A significant amount of progress has been made in the three years of this grant and this summarized in the 9 journals and conference papers that are included as appendices to this report. Our modeling had made progress in al aspects of simulating these complex devices including Teflon ablation, plasma formation, electro-magnetic acceleration, plume expansion, and particulate transport. Several different pulsed plasma thruster devices were modeled including an electro-thermal device (the PPT-4 developed at the University of Illinois by Dr. Rod Burton), and various micro-PPT's (developed at the Air Force Research Laboratory by Dr. Greg Spanjers and colleagues).
Download or read book 36th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 2000 3400 2000 3449 written by and published by . This book was released on 2000 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Pulsed Plasma Thruster Plume Study Symmetry and Impact on Spacecraft Surfaces written by Lynn A. Arrington and published by . This book was released on 2000 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Clustering Multiple Hall Thrusters on Plasma Plume Properties written by and published by . This book was released on 2003 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clusters of Hall thrusters have been proposed as a means of achieving electric propulsion systems capable of operating at very high power levels. To facilitate testing in existing vacuum facilities initial tests have focused on a cluster of low-power Busek BHT-2OO-X3 Hall thrusters. A combination of triple Laugmuir probes and floating emissive probes has been used to study the effects of multi-thruster operation on the electron number density, electron temperature, and plasma potential in the plasma plume. The resultant number density is shown to be a result of linear superposition of the plumes of individual thrusters while the electron temperature in the cluster plume is measured to be slightly higher than that caused by operation of a single thruster. The plasma potential downstream of the cluster is shown to obey the Boltzmann relation. In the region between the thrusters the plasma potential increases as a function of downstream distance and may result in reflection of some low-energy charge exchange ions back toward the cluster. A mechanism that may lead to slightly reduced ion beam divergence through focusing of ions directed toward the thruster centerline is discussed.
Download or read book Stationary Plasma Thruster Plume Characteristics written by and published by . This book was released on 1994 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analyses of TeflonTM Surface Charring and Near Field Plume of a Micro Pulsed Plasma Thruster written by and published by . This book was released on 2002 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Teflon(TM) ablation in a micro-Pulsed Plasma Thruster is studied with an aim to understand the charring phenomena. Microscopic analysis of the charred areas shows that it contains mainly carbon. It is concluded that the carbon char is formed as result of carbon flux returned from the plasma. A simplified model of the current layer near the Teflon(TM) surface is developed. The current density and the Teflon(TM) surface temperature have peaks near the electrodes that explain preferential ablation of these areas as was observed experimentally. The comparison of the temperature field and the ablation rate distribution with photographs of the Teflon(TM) surface shows that the area with minimum surface temperature and ablation rate corresponds to the charring area. This suggests that the charring may be related to a temperature effect. Electron densities predicted by the plume model are compared with near field measurements.
Download or read book Experimental and Theoretical Analysis of Pulsed Plasma Exhaust Plumes written by Dominic J. Palumbo and published by . This book was released on 1978 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed plasma plume diagnostic studies performed in the past have shown that considerable uncertainty exists because of the degree of backscatter encountered in ground test facilities. The large level of backscatter is attributable to the extremely high mass expulsion rate characteristic of solid propellant pulsed plasma thrusters (30 to 40 g/s on the average). The study reported upon herein had the objective of obtaining a suitable analytic model and computational scheme for calculation of the plume characteristics of a 23 mN-s pulsed plasma thruster. The calculated results were compared to experimental measurements of electron number density and temperature, obtained using specially designed Langmuir probes, only up to the point in the time when backscatter of plume effluents off the vacuum chamber walls became significant. A secondary objective of the program was to design a suitable driver circuit for the Langmuir Sangmuir probes so that a voltage ramp could be pulsed for one microsecond at any given time subsequent to thruster discharge initiation and the volt-ampere characteristic could be displayed on an XY oscilloscope.
Download or read book Fundamentals of Electric Propulsion written by Dan M. Goebel and published by John Wiley & Sons. This book was released on 2023-10-25 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Electric Propulsion Understand the fundamental basis of spaceflight with this cutting-edge guide As spacecraft engineering continues to advance, so too do the propulsion methods by which human beings can seek out the stars. Ion thrusters and Hall thrusters have been the subject of considerable innovation in recent years, and spacecraft propulsion has never been more efficient. For professionals within and adjacent to spacecraft engineering, this is critical knowledge that can alter the future of space flight. Fundamentals of Electric Propulsion offers a thorough grounding in electric propulsion for spacecraft, particularly the features and mechanisms underlying Ion and Hall thrusters. Updated in the light of rapidly expanding knowledge, the second edition of this essential guide detailed coverage of thruster principles, plasma physics, and more. It reflects the historic output of the legendary Jet Propulsion Laboratory and promises to continue as a must-own volume for spacecraft engineering professionals. Readers of the second edition of Fundamentals of Electric Propulsion readers will also find: Extensive updates to chapters covering hollow cathodes and Hall thrusters, based on vigorous recent research New sections covering magnetic shielding, cathode plume instabilities, and more Figures and homework problems in each chapter to facilitate learning and retention Fundamentals of Electric Propulsion is an essential work for spacecraft engineers and researchers working in spacecraft propulsion and related fields, as well as graduate students in electric propulsion, aerospace science, and space science courses.
Download or read book Instrument Development and Plasma Measurements on a 200 watt Hall Thruster Plume written by Yassir Azziz and published by . This book was released on 2003 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Magnetic Nozzle Configurations on Plasma Thrusters written by and published by . This book was released on 1997 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pulsed Plasma Thruster Plume Diagnostics written by Robert Eckman and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Arcjet Operating Condition and Constrictor Geometry on the Plasma Plume written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-06 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of plasma number density and electron temperature were obtained in the plumes of lab arcjet thrusters using electrostatic probes of both spherical and cylindrical geometry. The two arcjet thrusters used had different constrictor and/or nozzle geometries and operated on mixtures of nitrogen, hydrogen, and ammonia to simulate the decomposition products of hydrazine and ammonia. An increase in the measured electron density was observed for both geometries with increasing arc power at a constant mass flow rate and with increasing mass flow rate at a constant arc current. For a given operating condition, the electron number density decreased exponentially off centerline and followed an inverse distance squared relationship along the thrust axis. Typical measured electron temperatures ranged from 0.1 to 0.2 eV. Carney, Lynnette M. and Sankovic, John M. Glenn Research Center RTOP 506-42-31
Download or read book Pulsed Plasma Thruster Plume Characterization of Ion Species Using a Gridded Energy Analyzer written by Krystal Marie Parker and published by . This book was released on 2002 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Science and Technology written by Haikel Jelassi and published by BoD – Books on Demand. This book was released on 2019-02-27 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Usually called the "fourth state of matter," plasmas make up more than 99% of known material. In usual terminology, this term generally refers to partially or totally ionized gas and covers a large number of topics with very different characteristics and behaviors. Over the last few decades, the physics and engineering of plasmas was experiencing a renewed interest, essentially born of a series of important applications such as thin-layer deposition, surface treatment, isotopic separation, integrated circuit etchings, medicine, etc. Plasma Science
