Author: Y. RaitsesPublisher:
ISBN:
Category : Ion sources
Languages : en
Pages : 38
Book Description
Parametric Investigations of Non-conventional Hall Thruster
Author: Y. RaitsesPublisher:
ISBN:
Category : Ion sources
Languages : en
Pages : 38
Book Description
Parametric Investigations of Non-conventional Hall Thruster
Author: Y. RaitsesPublisher:
ISBN:
Category : Ion sources
Languages : en
Pages : 38
Book Description
Parametric Investigation of Miniaturized Cylindrical and Annular Hall Thrusters
Author: A. I. SmirnovPublisher:
ISBN:
Category : Electric propulsion
Languages : en
Pages : 29
Book Description
Prinzip und Satzungen des Greifswalder Wingolf
Author: Parametric Investigation of Miniaturized Cylindrical and Annular Hall Thrusters
Author: A. I. SmirnovPublisher:
ISBN:
Category : Electric propulsion
Languages : en
Pages : 29
Book Description
Fundamentals of Electric Propulsion
Author: Dan M. GoebelPublisher: John Wiley & Sons
ISBN: 0470436263
Category : Technology & Engineering
Languages : en
Pages : 528
Book Description
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.
An Exploration of Prominent Cusped-field Thruster Phenomena
Author: Taylor Scott MatlockPublisher:
ISBN:
Category :
Languages : en
Pages : 343
Book Description
A low power plasma thruster, initially dubbed the Diverging Cusped-Field Hall Thruster, was built at MIT in 2007 with the aim of providing an alternative to comparably sized conventional Hall thrusters able to provide enhanced lifetimes and thus deliver higher total impulses. The initial design was constrained in some respects by availability and inexpensiveness of materials rather than on experience based optimization due in part to the dearth of literature available for similar devices. While experiments suggest that the prototype Diverging Cusped-Field Thruster performs as well as mature Hall thruster designs, they have also revealed several operational quirks which could potentially pose problems for spacecraft integration. Dominant among these peculiarities are the existence of at least two distinct operational modes, marked by a steep jump in anode current and current oscillation amplitude, and, somewhat separately, the coalescence of the ion plume into a hollow cone-like structure with peak fluxes around 30 degrees from the thruster axis. This thesis describes the experimental and numerical work undertaken in an attempt to uncover the physical underpinnings of these two prominent cusped-field thruster phenomena. Stratification of the plasma plume into a wide-angle conical shell represents both a loss in thrust efficiency and a potential hazard for beam impingement on spacecraft surfaces. A method was envisaged to decrease the divergence of the beam using an external solenoid to re-contour the magnetic field near the thruster exit, where measurements suggest the critical ion acceleration occurs. Implementation of this method demonstrated clear vectoring of a large portion of the ion beam towards smaller angles in line with hypothesized effects, however a distinct, low-density, outer shell remained at the initial angle of divergence. Separately, the observed bifurcation in operational mode at normal conditions represents both a physically interesting display of plasma dynamics in the thruster discharge chamber and a potentially highly problematic feature, as operational envelopes in a particular mode have been observed to change unpredictably with experimental conditions. Attempts are made to experimentally isolate the factors which lead to bifurcation. The steady-state characteristics of the two modes are investigated using infrared thermography to monitor chamber temperatures while the unsteady behavior is monitored with an AC current probe on the discharge power supply. A thermal model of the thruster, using commercial finite-element-analysis software, is developed to validate plasma power deposition estimates from the thermography experiments. A prominent feature of the bifurcation is observed in the anode current spectrum, which changes from a quiescent mode to one exhibiting a strong relaxation oscillation at a fundamental frequency of several kilohertz. The nature of the oscillatory mode, and its transition to a highly damped state, is investigated through parametric scans of the thruster operating conditions. The main oscillation appears, from experiment, to be a breathing mode similar to those observed in Hall thrusters. An unsteady 1-D fluid code is adapted from the Hall thruster literature to model the interaction of neutral gas flow with the magnetically-limited electron current believed to be the main source of the instability. Trends in stability of the breathing mode with both thruster and model parameters, such as propellant flow rate, anode voltage, magnetic field, electron mobility and discharge chamber divergence are examined. A turbulent shear model is introduced to capture the effects of a time-evolving cross-field electron mobility on mode transitions and is shown to reproduce the experimentally observed oscillation damping at high voltages if the eddy turnover times are allowed to increase by modest intervals. The shear model is also able to naturally reproduce a feature of the anode current waveform, where a series of possible ionization avalanche events are muted before eventually leading to a large burst in current, which has not been captured by prior models.
36th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit: 2000-3100 - 2000-3149
Author: Fundamentals of Electric Propulsion
Author: Dan M. GoebelPublisher: John Wiley & Sons
ISBN: 1394163231
Category : Technology & Engineering
Languages : en
Pages : 564
Book Description
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.
Author: