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Book Assessment of the Plume Characteristics of a Miniaturized Pulsed Plasma Thurster

Download or read book Assessment of the Plume Characteristics of a Miniaturized Pulsed Plasma Thurster written by Richard Henry [Verfasser] Sypniewski Jr. and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed Plasma Thrusters are one of the most simplistic constructions in the electric propulsion family and are categorized among the electromagnetic class of thrusters. This classification of electromagnetics deals with the underlying physics of the pulsed plasma thruster and is much more complex with less understanding then other electric propulsion systems. However, due to the mechanical simplicity, wide range of specific impulses, non-toxic propellant, and the numerous applications, these thrusters are an ideal candidate for integrating into CubeSats. CubeSats are nanosatellites that are designed in three typical standard sizes (1 Unit, 2 Unit, and 3 Unit), each with standardized footprints. The smallest volumetric dimensions are the 1 Unit CubeSat, which is 10 x 10 x 10 cm. The volume and mass of CubeSats are quite small and therefore the miniaturization of the Pulsed Plasma Thruster is necessary to adhere to these constraints. Current research has shown that when miniaturization of a Pulsed Plasma Thruster there is a tendency for the thruster to work and perform in the electrothermal regime rather than in the electromagnetic one. Understanding which regime the thruster is operating in is critical for understanding how to optimize the design. For example, a thruster operates with higher efficiencies in the electromagnetic regime because there is much less loss from Ohmic heating. Preliminary testing of the Micro-Pulsed Plasma Thruster design was performed by the research company called FOTEC and determined a thruster chamber design. To understand thoroughly the Micro-Pulsed Plasma Thruster, characterization of the thruster and its plume will be conducted experimentally. This characterization will determine parametric features such as current/voltage waveform, electron temperatures, electron densities, and exhaust velocities. Performing the initial characterizations will give insight into the Micro-Pulsed Plasma Thruster and will provide further understanding into the regime that the thruster is operating in. The characteristics that resulted from this thesis concluded that the Micro-Pulsed Plasma Thruster is operating in the electromagnetic regime. This was concluded based on several characteristic traits that only conclude for electromagnetic acceleration mechanisms. These were that the peak currents reached were approximately 5,000 A and the exhaust velocity was in the 50 km/sec range. Further information was measured and the total resistance and inductance was calculated to be 13 m and 24 nH. Details on this information and how it was calculated is discussed in this thesis.*****Pulsed Plasma Thrusters are one of the most simplistic constructions in the electric propulsion family and are categorized among the electromagnetic class of thrusters. This classification of electromagnetics deals with the underlying physics of the pulsed plasma thruster and is much more complex with less understanding then other electric propulsion systems. However, due to the mechanical simplicity, wide range of specific impulses, non-toxic propellant, and the numerous applications, these thrusters are an ideal candidate for integrating into CubeSats. CubeSats are nanosatellites that are designed in three typical standard sizes (1 Unit, 2 Unit, and 3 Unit), each with standardized footprints. The smallest volumetric dimensions are the 1 Unit CubeSat, which is 10 x 10 x 10 cm. The volume and mass of CubeSats are quite small and therefore the miniaturization of the Pulsed Plasma Thruster is necessary to adhere to these constraints. Current research has shown that when miniaturization of a Pulsed Plasma Thruster there is a tendency for the thruster to work and perform in the electrothermal regime rather than in the electromagnetic one. Understanding which regime the thruster is operating in is critical for understanding how to optimize the design. For example, a thruster operates with higher efficiencies in the electromagne

Book Characterization of an Exploding Micro wire Pulsed Plasma Thruster

Download or read book Characterization of an Exploding Micro wire Pulsed Plasma Thruster written by Diego Mejia Montano and published by . This book was released on 2019 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed Plasma Thrusters typically live in the low-range efficiency realm compared to other types of electric propulsion thrusters. In an attempt to explore if any added benefits could be gained from experimenting with a new propellant type, additional physics had to be incorporated into the classical RLC model approach. A study into modeling how a micro-wire propellant would react when subjected to energy deposition via current-driven heating was undertaken. Once a first-order estimate, verified with computational estimates, was obtained then the classical RLC series circuit model could be used to compare and validate the results obtained from experimentation. It was found that while the proposed propellant type is feasible, it produced performance differences that could not be explained solely by the classical model and a more exhaustive investigation into various phenomena will have to be pursued.

Book Electromagnetic Effects in the Near Field Plume Exhaust of a Micro Pulsed Plasma Thruster

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.

Book Experimental and Theoretical Analysis of Pulsed Plasma Exhaust Plumes

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.

Book Performance Characterization of a High Efficiency Gas fed Pulsed Plasma Thruster

Download or read book Performance Characterization of a High Efficiency Gas fed Pulsed Plasma Thruster written by John K. Ziemer and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book High order Modeling of Micro pulsed Plasma Thrusters

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:

Book Fundamentals of Electric Propulsion

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.

Book Advanced Diagnostics for Millimeter Scale Micro Pulsed Plasma Thrusters

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.

Book Pulsed Plasma Plume Studies

Download or read book Pulsed Plasma Plume Studies written by William J. Guman and published by . This book was released on 1977 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exhaust plume of a millipound thrust level pulsed plasma thruster was studied in a vacuum chamber having all walls cooled by liquid nitrogen. This thruster has a propulsive performance capable of meeting North-South station-keeping requirements of satellites. The major source of contamination of a surface located in the facility was identified to be mainly due to mass being scattered off the walls of the test facility because the walls were incapable of absorbing the highly energetic plume of the first encounter with the wall. By means of a Langmuir probe, calorimetric discs, a collimated QCM and collimated glass capture cups it was found that the transient plume is fairly well collimated and that the outer extremities of the plume are located within + or - 30 degrees to + or - 40 degrees with respect to the geometric center line of the thruster that was studied. Whether or not major changes of the exhaust cone would change this location was not examined. Time resolved studies of the plume by a Langmuir probe and a photocell has shown the life of the plume at a region in space to be only a few tens of microseconds. This result reveals that a spacecraft surface exposed over a 5 to 7 year period to the plume of a North-South station keeping thruster will actually see an accumulated plume flow time for only about 5 minutes during that mission time.

Book End of life Stationary Plasma Thruster Far field Plume Characterization

Download or read book End of life Stationary Plasma Thruster Far field Plume Characterization written by Eric J. Pencil and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Plume Characterization of a One Millipound Solid Teflon Pulsed Plasma Thruster

Download or read book Plume Characterization of a One Millipound Solid Teflon Pulsed Plasma Thruster written by L. C. Pless and published by . This book was released on 1978 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: An evaluation was made of the pulsed plasma thruster plume-wall backscatter characteristics of the MOLSINK facility. On the thruster axis, this backscatter drops off to zero as the angle between the axis and wall location reaches 40. This wall backscatter was found to be essentially symmetric about the plume axis. The total integrated backscatter from the MOLSINK wall is approximately equal to 5% of the total mass injected from the pulsed plasma thruster during the discharge pulse.

Book Thrust and Performance Study of Micro Pulsed Plasma Thrusters

Download or read book Thrust and Performance Study of Micro Pulsed Plasma Thrusters written by Jeremy J. Selstrom and published by . This book was released on 2010 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: