Author: John E. FosterPublisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
Enhanced Discharge Performance in a Ring Cusp Plasma Source
Author: John E. FosterEnhanced Discharge Performance in a Ring Cusp Plasma Source
Author: Overcoming the Scaling Limitations of Ring-Cusp DC Ion Thruster Discharges
Author: Ben DankongkakulPublisher:
ISBN:
Category :
Languages : en
Pages : 209
Book Description
Ion thruster discharges exhibit impressive performance at conventional scales (~30 cm in diameter); however, scaling to smaller sizes (~3 cm) presents considerable challenges. This research effort addresses the miniaturization of direct current (DC) discharges via a series of careful investigations (i.e., near-field cusp-confinement, discharge experiments, computational efforts, and theoretical analyses). These investigations provided insight into the plasma behavior and loss mechanisms within small-scale DC discharges. This insight was then used to develop and demonstrate a highly efficient miniature-scale DC ion source called the Axial Ring-Cusp Hybrid (ARCH) discharge. Implemented as a 3 cm ion thruster, it can potentially achieve a discharge loss of 160 eV/ion and mass utilization efficiencies of 0.89 -- performance values that have previously only been attainable by conventional-scale discharges (>10 cm). The improve performance will greatly expand the mission capabilities of many future spacecraft missions by providing the high efficiency of ion thrusters at small powers and scales. This thesis describes 3 efforts that were undertaken to better understand cusp-confinement physics and miniature DC discharge behavior. Since small-scale DC discharges are limited by their ability to effectively utilize the high-energy primary electrons, the first effort began with experiments utilizing an electron flood gun to investigate the loss behavior of magnetically-confined primary electrons. It was found that increasing the complexity of the upstream field affected the spatial complexity of the loss area. These efforts showed that, in contrast to existing theory, the primary electron loss can be strongly influenced by the upstream magnetic fields. This behavior is particularly important and noticeable for miniature-scale discharges where small perturbations of the primary electron's gyro-center are preserved from one cusp to the next. The second effort was then used to investigate the overall confinement behavior of a cusp discharge, to baseline the probing techniques for magnetized plasma discharges, and to validate computational models. It was found that the plasma electron temperature and primary electron density must be analyzed via the electron energy distribution function (EEDF) data. The interpreted primary electron density showed good quantitative agreement with computational simulations. The final effort was to investigate and improve the discharge efficiency of miniature-scale DC ion thruster discharges. The plasma parameter maps for several magnetic field and discharge conditions were analyzed in conjunction with estimated performance measurements. For the 3 cm Miniature Xenon Ion (MiXI) thruster, the detail discharge maps revealed the mechanisms responsible for the MiXI's flat beam profile and high discharge loss. Analyses of the ionization rates confirm previous computational findings that the plasma within the original MiXI design is created almost entirely by direct primary electron ionization of the xenon gas. Multiple ring cusp configurations (i.e., 3-ring, 4-ring, and 5-ring) were also examined. These efforts revealed that a major redesign is necessary to avoid some of the inherent limitations of ring-cusp discharges at the miniature scale. Ultimately, a new discharge design called the ARCH discharge was developed. Performance data and discharge maps show that this approach provides high primary electron confinement, high plasma electron density, high plasma uniformity along the extraction plane, and discharge performance that may rival well-designed conventionally-sized ion thrusters.
Internal Plasma Properties and Enhanced Performance of an 8 Cm Ion Thruster Discharge
Author: Introduction to Plasmas and Plasma Dynamics
Author: Hai-Bin TangPublisher: Elsevier
ISBN: 0443137005
Category : Technology & Engineering
Languages : en
Pages : 421
Book Description
Introduction to Plasmas and Plasma Dynamics: With Plasma Physics Applications to Space Propulsion, Magnetic Fusion and Space Physics, Second Edition provides an accessible introduction to the understanding of high temperature, ionized gases necessary to conduct research and develop applications related to plasmas. Thoroughly updated and expanded, this sec Describes plasma applications with close reference to elementary processes, promoting a deeper understanding of plasmas in new fields Provides structured problems in every chapter that help readers grasp the book’s practical lessons Includes a new chapter on numerical methods in plasmas that adds crucial context for experimental approaches
41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 10-13 July 2005, Tucson, Arizona: 05-3650 - 05-3699
Author: Scientific and Technical Aerospace Reports
Author: Ion Implantation Technology - 92
Author: D.F. DowneyPublisher: Elsevier
ISBN: 0444599800
Category : Technology & Engineering
Languages : en
Pages : 716
Book Description
Ion implantation technology has made a major contribution to the dramatic advances in integrated circuit technology since the early 1970's. The ever-present need for accurate models in ion implanted species will become absolutely vital in the future due to shrinking feature sizes. Successful wide application of ion implantation, as well as exploitation of newly identified opportunities, will require the development of comprehensive implant models. The 141 papers (including 24 invited papers) in this volume address the most recent developments in this field. New structures and possible approaches are described. The implications for ion implantation technology as well as additional observations of needs and opportunities are discussed. The volume will be of value to all those who are interested in acquiring a more complete understanding of the current developments in ion implantation processes and comprehensive implant models.
Aerospace and Associated Technology
Author: Anup GhoshPublisher: Taylor & Francis
ISBN: 1000844579
Category : Technology & Engineering
Languages : en
Pages : 607
Book Description
The International Conference on Theoretical Applied Computational and Experimental Mechanics is organized every three years by the Department of Aerospace Engineering IIT Kharagpur. The conference is devoted to providing a platform for scientists and engineers to exchange their views on the latest developments in Mechanics since 1998. ICTACEM Conference is aimed at bringing together academics and researchers working in various disciplines of mechanics to exchange views as well as to share knowledge between people from different parts of the globe. The 8th ICTACEM was held from December 20-22, 2021, at the Indian Institute of Technology, Kharagpur.
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