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Ion Current Density Study Of The Nasa 300m And Nasa 457mv2 Hall Thrusters
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Book Synopsis Ion Current Density Study of the Nasa-300m and Nasa-457mv2 Hall Thrusters by : Wensheng Huang
Download or read book Ion Current Density Study of the Nasa-300m and Nasa-457mv2 Hall Thrusters written by Wensheng Huang and published by BiblioGov. This book was released on 2013-06 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: NASA Glenn Research Center is developing a Hall thruster in the 15-50 kW range to support future NASA missions. As a part of the process, the performance and plume characteristics of the NASA-300M, a 20-kW Hall thruster, and the NASA-457Mv2, a 50-kW Hall thruster, were evaluated. The collected data will be used to improve the fidelity of the JPL modeling tool, Hall2De, which will then be used to aid the design of the 15-50 kW Hall thruster. This paper gives a detailed overview of the Faraday probe portion of the plume characterization study. The Faraday probe in this study is a near-field probe swept radially at many axial locations downstream of the thruster exit plane. Threshold-based integration limits with threshold values of 1/e, 1/e2, and 1/e3 times the local peak current density are tried for the purpose of ion current integration and divergence angle calculation. The NASA-300M is operated at 7 conditions and the NASA-457Mv2 at 14 conditions. These conditions span discharge voltages of 200 to 500 V and discharge power of 10 to 50 kW. The ion current density profiles of the near-field plume originating from the discharge channel are discovered to strongly resemble Gaussian distributions. A novel analysis approach involving a form of ray tracing is used to determine an effective point of origin for the near-field plume. In the process of performing this analysis, definitive evidence is discovered that showed the near-field plume is bending towards the thruster centerline.
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721604029 Total Pages :36 pages Book Rating :4.6/5 (4 download)
Book Synopsis Recent Results from Internal and Very-Near-Field Plasma Diagnostics of a High Specific Impulse Hall Thruster by : National Aeronautics and Space Administration (NASA)
Download or read book Recent Results from Internal and Very-Near-Field Plasma Diagnostics of a High Specific Impulse Hall Thruster 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 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Floating potential and ion current density measurements were taken on the laboratory model NASA-173Mv2 in order to improve understanding of the physical processes affecting Hall thruster performance at high specific impulse. Floating potential was measured on discharge chamber centerline over axial positions spanning 10 mm from the anode to 100 mm downstream of the exit plane. Ion current density was mapped radially up to 300 mm from thruster centerline over axial positions in the very-near-field (10 to 250 mm from the exit plane). All data were collected using a planar probe in conjunction with a high-speed translation stage to minimize probe-induced thruster perturbations. Measurements of floating potential at a xenon flow rate of 10 mg/s have shown that the acceleration layer moved upstream 3 1 mm when the voltage increased from 300 to 600 V. The length of the acceleration layer was 14 2 mm and was approximately constant with voltage and magnetic field. Ion current density measurements indicated the annular ion beam crossed the thruster centerline 163 mm downstream of the exit plane. Radial integration of the ion current density at the cathode plane provided an estimate of the ion current fraction. At 500 V and 5 mg/s, the ion current fraction was calculated as 0.77. Hofer, Richard R. and Gallimore, Alec D. and Jacobson, David (Technical Monitor) Glenn Research Center NASA/CR-2003-212604, E-14162, IEPC-2003-037
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721607761 Total Pages :32 pages Book Rating :4.6/5 (77 download)
Book Synopsis The Influence of Current Density and Magnetic Field Topography in Optimizing the Performance, Divergence, and Plasma Oscillations of High Specific Impulse Hall Thrusters by : National Aeronautics and Space Administration (NASA)
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
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721674022 Total Pages :38 pages Book Rating :4.6/5 (74 download)
Book Synopsis Efficiency Analysis of a High-Specific Impulse Hall Thruster by : National Aeronautics and Space Administration (NASA)
Download or read book Efficiency Analysis of a High-Specific Impulse Hall Thruster written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance and plasma measurements of the high-specific impulse NASA-173Mv2 Hall thruster were analyzed using a phenomenological performance model that accounts for a partially-ionized plasma containing multiply-charged ions. Between discharge voltages of 300 to 900 V, the results showed that although the net decrease of efficiency due to multiply-charged ions was only 1.5 to 3.0 percent, the effects of multiply-charged ions on the ion and electron currents could not be neglected. Between 300 to 900 V, the increase of the discharge current was attributed to the increasing fraction of multiply-charged ions, while the maximum deviation of the electron current from its average value was only +5/-14 percent. These findings revealed how efficient operation at high-specific impulse was enabled through the regulation of the electron current with the applied magnetic field. Between 300 to 900 V, the voltage utilization ranged from 89 to 97 percent, the mass utilization from 86 to 90 percent, and the current utilization from 77 to 81 percent. Therefore, the anode efficiency was largely determined by the current utilization. The electron Hall parameter was nearly constant with voltage, decreasing from an average of 210 at 300 V to an average of 160 between 400 to 900 V. These results confirmed our claim that efficient operation can be achieved only over a limited range of Hall parameters. Jacobson, David (Technical Monitor) and Hofer, Richard R. and Gallimore, Alec D. Glenn Research Center NASA/CR-2004-213212, E-14720, AIAA Paper 2004-3602
Book Synopsis Ion Thruster Development at NASA Lewis Research Center by :
Download or read book Ion Thruster Development at NASA Lewis Research Center written by and published by . This book was released on 1992 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Ion Engine and Hall Thruster Development at the NASA Glenn Research Center by :
Download or read book Ion Engine and Hall Thruster Development at the NASA Glenn Research Center written by and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis High Power Hall Thrusters by : Robert Jankovsky
Download or read book High Power Hall Thrusters written by Robert Jankovsky and published by . This book was released on 1999 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Plasma Potential and Langmuir Probe Measurements in the Near-Field Plume of the Nasa 300m Hall Thruster by : Daniel A. Herman
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
Book Synopsis Environment of Mars, 1988 by : David Kaplan
Download or read book Environment of Mars, 1988 written by David Kaplan and published by . This book was released on 1988 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Improving Water Management Recent OECD Experience by : OECD
Download or read book Improving Water Management Recent OECD Experience written by OECD and published by OECD Publishing. This book was released on 2003-02-21 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication brings together the recent work of the OECD on water management issues. It identifies the main policy challenges addressed by that work for sustainable water management.
Book Synopsis HIE-ISOLDE: the Technical Options by : European Organization for Nuclear Research
Download or read book HIE-ISOLDE: the Technical Options written by European Organization for Nuclear Research and published by . This book was released on 2006 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Liquefaction of Gases by : Michael Faraday
Download or read book The Liquefaction of Gases written by Michael Faraday and published by . This book was released on 1896 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
