Download or read book Probe Measurements of Plasma Properties Inside an Experimental Hall Thruster written by Y. Raitses 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 Performance Testing and Internal Probe Measurements of a High Specific Impulse Hall Thruster written by Noah Zachary Warner and published by . This book was released on 2003 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The BHT-1000 high specific impulse Hall thruster was used for performance testing and internal plasma measurements to support the ongoing development of computational models. The thruster was performance tested in both single and two stage anode configurations. In the single stage configuration, the specific impulse exceeded 3000s at a discharge voltage of 1000V while maintaining a thrust efficiency of 50 percent. Two stage operation produced higher thrust, specific impulse and thrust efficiency than the single stage configuration at most discharge voltages. The thruster thermal warmup was characterized using a thermocouple embedded in the outer exit ring, and the magnetic field topology was investigated using a Gaussmeter. The single stage thruster configuration was outfitted with a series of axially distributed Langmuir probes to determine plasma properties inside the discharge channel. Probe data were taken at discharge voltages between 300-900V. Axial profiles of electron temperature, electron density, and plasma potential were measured and compared to results of a previously developed two dimensional particle-in-cell simulation of the BHT-1000 thruster. The experimental data matched the simulation results well, particularly in profiles of electron temperature and plasma potential at low discharge voltages. The peak electron temperature was shown to depend on discharge voltage through a power law relationship in both the experimental and simulated data. The greatest discrepancies between experimental data and simulation results were found to be in comparisons of electron density, where it appears that the simulation may be "smearing" the plasma over too wide of an axial region. Hypotheses for this behavior were discussed along with recommendations for future work.

Download or read book A Preliminary Investigation of Hall Thruster Technology written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-10-21 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-year NASA/BMDO-sponsored experimental program to conduct performance and plume plasma property measurements on two Russian Stationary Plasma Thrusters (SPTs) has been completed. The program utilized experimental facilitates at the University of Michigan's Plasmadynamics and Electric Propulsion Laboratory (PEPL). The main features of the proposed effort were as follows: (1) Characterized Hall thruster (and arcjet) performance by measuring ion exhaust velocity with probes at various thruster conditions; (2) Used a variety of probe diagnostics in the thruster plume to measure plasma properties and flow properties including T(sub e) and n(sub e) ion current density and ion energy distribution, and electric fields by mapping plasma potential; (3) Used emission spectroscopy to identify species within the plume and to measure electron temperatures. A key and unique feature of our research was our collaboration with Russian Hall thruster researcher Dr. Sergey A Khartov, Deputy Dean of International Relations at the Moscow Aviation Institute (MAI). His activities in this program included consulting on and participation in research at PEPL through use of a MAI-built SPT and ion energy probe. Gallimore, Alec D. Glenn Research Center NAG3-1504...

Download or read book Plasma Potential and Langmuir Probe Measurements in the Near Field Plume of the Nasa 300m Hall Thruster written by Daniel A. Herman and published by BiblioGov. This book was released on 2013-06 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to aid in the design of high-power Hall thrusters and provide experimental validation for existing modeling efforts, plasma potential and Langmuir probe measurements were performed in the near-field plume of the NASA 300M Hall thruster. A probe array consisting of a Faraday probe, Langmuir probe, and emissive probe was used to interrogate the plume from approximately 0.1 - 2.0 DT, m downstream of the thruster exit plane at four operating conditions: 300 V, 400 V, and 500 V at 20 kW as well as 300 V at 10 kW. Results show that the acceleration zone and high-temperature region were contained within 0.3 DT, m from the exit plane at all operating conditions. Isothermal lines were shown to strongly follow magnetic field lines in the nearfield, with maximum temperatures ranging from 19 - 27 eV. The electron temperature spatial distribution created large drops in measured floating potentials in front of the magnetic pole surfaces where the plasma density was small, which suggests strong sheaths at these surfaces. The data taken have provided valuable information for future design and modeling validation, and complements ongoing internal measurement efforts on the NASA 300

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 Experimental Investigations of Plasma Parameters and Species dependent Ion Energy Distribution in the Plasma Exhaust Plume of a Hall Thruster written by Sang-Wook Kim and published by . This book was released on 1999 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Investigations of Probe Induced Perturbations in a Hall Thruster written by D. Staack and published by . This book was released on 2002 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electrostatic Probe with Shielded Probe Insulator Tube for Low Disturbing Plasma Measurements in Hall Thrusters written by D. Staack and published by . This book was released on 2003 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Langmuir Probe in Theory and Practice written by Evgeny V. Shun'ko and published by Universal-Publishers. This book was released on 2009 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: From flat-panel televisions to thermonuclear fusion for energy production, plasmas currently have numerous and wide applications in sciences and industry. A diversity of plasma diagnostics is available to physicists and engineers to measure and control plasma parameters. Among them, the Langmuir probe is the most inexpensive and most popular instrument and method. The Langmuir probe is a small electrode which is submerged in plasma in order to measure the probe current-voltage characteristic. The same characteristic is processed further to derive the electron and ion concentration, the electron distribution function, and the plasma potential at the probe location. Langmuir probe diagnostics afford rapid measurements of the electron distribution function and plasma potential at a good time resolution, 10-8 seconds in a wide range of plasma densities 10+3 - 10+14 cm-3, and the electron energy from the room temperature to hundreds of electron-volts - qualities which are essential for researchers. In view of these facts, Langmuir probe diagnostics are applied very frequently to measuring plasma parameters. This book will be useful in teaching plasma diagnostics to undergraduate and graduate students in plasma physics courses. And it will also serve as a practical reference manual for physicists and engineers working in the growing area of plasma physics. The reader of this book will learn what kind of plasma parameters the Langmuir probe can measure, how to develop the probe diagnostics for specific cases, and how the probe data obtained should be processed to deduce reliable plasma parameters. In this book, the reader can find not only the basic physics information important to understanding the principles of probe operation, but also how the "real" probe disturbs plasma, and how it is possible to reconstruct undisturbed plasma parameters with available probe data.

Download or read book Plasma Properties in the Plume of a Hall Thruster Cluster written by and published by . This book was released on 2003 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hall thruster cluster is an attractive propulsion approach for spacecraft requiring very high-power electric propulsion systems. This article presents plasma density, electron temperature, and plasma potential data collected with a combination of triple Langmuir probes and floating emissive probes in the plume of a low-power, four-engine Hall thruster cluster. Simple analytical formulas are introduced that allow these quantities to be predicted downstream of a cluster based solely on the known plume properties of a single thruster. Ion energy distribution functions measured using both a parallel plate electrostatic analyzer and a retarding potential analyzer are presented. A cluster of Hall thrusters is shown to exhibit dramatically different ion energy profiles compared to a single thruster. In particular, clustering causes a significant increase in the fraction of ions at energies below the primary peak in the distribution, most likely due to an increase in elastic scattering and the effects of the unique plasma potential profiles in the cluster plume.

Download or read book Plasma Potential and Langmuir Probe Measurements in the Near Field Plume of the Nasa 457mv2 Hall Thruster written by Rohit Shastry and published by BiblioGov. This book was released on 2013-06 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NASA Technical Reports Servcr (NTRS) houses half a million publications that are a valuable means of information to researchers, teachers, students, and the general public. These documents are all aerospace related with much scientific and technical information created or funded by NASA. Some types of documents include conference papers, research reports, meeting papers, journal articles and more. This is one of those documents.

Download or read book 34th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit written by and published by . This book was released on 1998 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plasma Properties Downstream of a Low Power Hall Thruster POSTPRINT written by and published by . This book was released on 2005 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Triple Langmuir probes and emissive probes were used to measure the electron number density, electron temperature, and plasma potential downstream of a low-power Hall thruster. The results show a polytropic relation between electron temperature and electron number density throughout the sampled region. Over a large frat ion of the plume, the plasma potential obeys the predictions of ambipolar expansion. Near the thruster centerline, however, observations show larger gradients of plasma potential than can be accounted for by this means. Radial profiles of plasma potential in the very-near-field plume are shown to contain large gradients that correspond in location to the boundaries of a visually intense plasma region. [Copyright 2005 American Institute of Physics.].

Download or read book Analytical Extraction of Plasma Properties Using a Hall Thruster Efficiency Architecture preprint written by Daniel L. Brown and published by . This book was released on 2007 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An investigation of the conversion from anode electrical energy to jet kinetic energy in a laboratory model Hall thruster test-bed yielded an experimentally determined thrust efficiency based on the product of propellant, voltage, and current utilization. This method accounts for the effects of the ion velocity distribution function (VDF), electron recycle fraction, plume divergence, and the fractional loss of acceleration voltage within the discharge chamber. 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. A systematic investigation of the performance and far-field plume measurements provided insight into the loss mechanisms and plasma properties from 100 to 400 V discharge. Experimental parameter groups are calculated based on the measured thrust and telemetry data. When interpreted with measured ion beam current and most probable ion voltage, the efficiency analysis enables several plasma parameters to be deciphered, including: average ion charge, ionization mass fraction, and momentum beam divergence half-angle."--P. [i].

Download or read book 35th AIAA ASME SAE ASEE Joint Propulsion Conference and Exhibit written by and published by . This book was released on 1999 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of Plasma Potential Distribution in Segmented Electrode Hall Thruster written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Use of a segmented electrode placed at the Hall thruster exit can substantially reduce the voltage potential drop in the fringing magnetic field outside the thruster channel. In this paper, we investigate the dependence of this effect on thruster operating conditions and segmented electrode configuration. A fast movable emissive probe is used to measure plasma potential in a 1 kW laboratory Hall thruster with semented electrodes made of a graphite material. Relatively small probe-induced perturbations of the thruster discharge in the vicinity of the thruster exit allow a reasonable comparison of the measured results for different thruster configurations. It is shown that the plasma potential distribution is almost not sensitive to changes of the electrode potential, but depends on the magnetic field distribution and the electrode placement.