Download or read book High Resolution Laser Diagnostics in Millimeter Scale Micro Pulsed Plasma Thrusters written by and published by . This book was released on 2002 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A class of Micro-Pulsed Plasma Thruster (MicroPPT) is being developed to provide precise attitude control and stationkeeping ability to 25-kg class satellites. Operating by means of a surface discharge across a Teflon propellant fuel bar only a few millimeters in diameter, the MicroPPT delivers a thrust-to-power ratio of 5 - 10 Micro-N-s/J. Due to the low pulse energy and size, the MicroPPT produces a spatially confined and diffuse plasma plume that is difficult to analyze with material probes for validation of plume modeling. To this end, a Herriott Cell interferometer is introduced to measure the plume electron and neutral densities. By focusing a large number of laser beams into a small measurement volume, the Herriott Cell can increase the instrument resolution by a factor of about 10, compared to a single-pass interferometer, with minimal degradation of spatial resolution. Comparison of these results with a 2 colors, 2-pass interferometer demonstrates experimental validity of the point measurement technique used. Comparison of the measured electron density with modeling predictions by Keidar and Boyd shows close agreement. Attempts to measure the MicroPPT neutral density with a 2 colors configuration of the Herriott Cell interferometer were inconclusive, in spite of previous successes using this technique on larger PPTs.
Download or read book Advanced Diagnostics for Millimeter Scale Micro Pulsed Plasma Thrusters written by and published by . This book was released on 2002 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A class of Micro-Pulsed Plasma Thrusters (MicroPPTs) is being developed by the Air Force Research Laboratory (AFRL) to provide precise attitude control and stationkeeping ability to 25-kg class satellites. Operating by means of a surface discharge across a Teflon(TM) propellant fuel bar only a few millimeters in diameter, the MicroPPT delivers a thrust-to-power ratio of 5 - 10 microN-s/J. Due to the low pulse energy and size, the MicroPPT produces a spatially-confined and diffuse plasma plume that is difficult to analyze with material probes. Efforts to characterize MicroPPT plume are underway. To this end, a Herriott Cell interferometer is introduced to establish the plume electron and neutral densities. Comparison of the measured electron density with modeling predictions shows close agreement. Additionally, a Pockels cell has been developed to provide a zero-impedance MicroPPT breakdown voltage measurement. Current research focuses on an infrared-emission measurement capability to determine propellant surface temperature during thruster operation.
Download or read book Plasma Engineering written by Michael Keidar and published by Academic Press. This book was released on 2018-08-06 with total page 587 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma Engineering, Second Edition, applies the unique properties of plasmas (ionized gases) to improve processes and performance over many fields, such as materials processing, spacecraft propulsion and nanofabrication. The book considers this rapidly expanding discipline from a unified standpoint, addressing fundamentals of physics and modeling, as well as new and real-word applications in aerospace, nanotechnology and bioengineering. This updated edition covers the fundamentals of plasma physics at a level suitable for students using application examples and contains the widest variety of applications of any text on the market, spanning the areas of aerospace engineering, nanotechnology and nanobioengineering. This is highly useful for courses on plasma engineering or plasma physics in departments of Aerospace Engineering, Electrical Engineering and Physics. It is also useful as an introduction to plasma engineering and its applications for early career researchers and practicing engineers. Features new material relevant to application, including emerging areas of plasma nanotechnology and medicine Contains a new chapter on plasma-based control, as well as a description of RF and microwave-based plasma applications, plasma lighting, reforming and other most recent application areas Provides a technical treatment of the fundamental and engineering principles used in plasma applications
Download or read book 38th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit 02 4250 02 4299 written by and published by . This book was released on 2002 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Diagnostics of Plasma Thrusters written by Thomas M. York and published by . This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research involves diagnostics studies of plasma thrusters. These devices generate ionized gases which are accelerated at thermal and electromagnetic modes. The research effort uses the new, high resolution diagnostic techniques that will determine electron densities, local magnetic fields and density fluctuations indicating anomalous transport. A long wavelength carbon dioxide laser which allows more sensitive measurements, with its long wavelength, is used. The laser will be coupled with a Far infrared Laser System capable of generating beams around ten milliwatt levels, and provide a diagnostic study that has not yet been used in thruster plasma diagnosis. Keywords: Laser diagnostics; Multi-beam interferometry; Fluctuation. (JHD).
Download or read book 39th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit July 20 23 2003 Huntsville Alabama 03 5150 03 5199 written by and published by . This book was released on 2003 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High order Modeling of Micro pulsed Plasma Thrusters written by Guang Lin and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book IR and FIR Laser Diagnostics for Plasma Thrusters Using a CW CO2 Radiation Source written by and published by . This book was released on 1992 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research involves diagnostic studies of plasma thrusters. This effort will use the new, high resolution diagnostic techniques that will determine electron densities, local magnetic fields, and density fluctuations indicating anomalous transport.
Download or read book Laser and Plasma in Micro and Nano scale Materials Processing and Diagnostics written by European Material Research Society and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Laser Induced Fluorescence Characterization of Cusped Field Plasma Thrusters written by Natalia Adrienne MacDonald and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cusped field plasma thrusters are a recent development in electrostatic propulsion, aimed at improving operation in the low power regime. Several diagnostic techniques have been employed to characterize these discharges. The present study focuses on the use of laser induced fluorescence to map ion velocities throughout the plumes of several cusped field thruster variants. Laser induced fluorescence provides the opportunity to probe small plasma sources with high spatial resolution, and is particularly useful for studying plasma propulsion devices where hot, energetic and highly non-uniform environments can adversely affect intrusive probes. The first half of this thesis focuses on time-averaged laser induced fluorescence velocimetry for three cusped-field thrusters. While a time-averaged velocity diagnostic is adequate in determining overall performance, it cannot resolve the dynamics seen in oscillatory modes of thruster operation. The second half of this research focuses on the development of an advanced CW laser induced fluorescence diagnostic technique, capable of correlating high frequency current fluctuations to the resulting fluorescence excitation lineshapes. This method is validated using simulations and a 60 Hz xenon spectral lamp. It is then applied to an oscillatory mode of the diverging cusped field thruster. Results show that the positions of the ionization and peak acceleration regions in the thruster vary over the course of a discharge current oscillation, causing the ion velocities to fluctuate in time. This new method of time-synchronized CW laser-induced fluorescence will be invaluable for better understanding the dynamics of thruster operation as well as other quasi-periodic oscillatory discharges, in fields from combustion to materials processing, among others.
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 Beamed Energy Propulsion written by Kimiya Komurasaki and published by AIP Conference Proceedings (Nu. This book was released on 2006-05-31 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises the proceedings of the Fourth International Symposium on Beamed Energy Propulsion, offering the latest progress in the field of advanced space propulsion systems powered by laser, microwave, and charged beams, covering aspects from fundamental issues to future space exploration plans. Topics include: fluid dynamics in air-breathing laser propulsion; laser supported detonation and energy deposition; lightcraft; laser in-tube thruster; ablative propulsion and microthrusters; liquid propellant and more.
Download or read book Fusion Energy Update written by and published by . This book was released on 1981 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space Station Systems written by and published by . This book was released on 1987 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MEMS Mirrors written by Huikai Xie and published by MDPI. This book was released on 2018-05-04 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "MEMS Mirrors" that was published in Micromachines
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1994 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:
