DOCSLIB.ORG

A Langmuir Probe Instrument for Research in The

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Langmuir Probe Instrument for Research in The The Pennsylvania State University The Graduate School College of Engineering A LANGMUIR PROBE INSTRUMENT FOR RESEARCH IN THE TERRESTRIAL IONOSPHERE A Thesis in Electrical Engineering by Adam C. Escobar © 2009 Adam C. Escobar Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science May 2009 The thesis of Adam C. Escobar was reviewed and approved* by the following: Sven G. Bilén Associate Professor of Engineering Design, Electrical Engineering, and Aerospace Engineering Thesis Advisor John D. Mitchell Professor of Electrical Engineering W. Kenneth Jenkins Professor of Electrical Engineering Head of the Department of Electrical Engineering *Signatures are on file in the Graduate School ii ABSTRACT Langmuir probes have been used for plasma diagnostics on spacecraft ever since the first sounding rockets in the 1950s. As each decade passed, there have been improvements to the instrument design in order to obtain a more accurate solution to the plasma characteristics. In this thesis, a Langmuir probe instrument is designed and tested for use in the Earth’s ionosphere. The design includes the probe and boom development, as well as the on-board electronics. The probe is cylindrical and sized using orbital-motion-limited theory. The on-board electronics include two electrometers, two calibration boards, a control and processing board, and a power regulation board. Raw data is sent to the on-board spacecraft computer, where the computer can process the data or send raw data down to the data downlink ground station. The instrument has the capability to clean the probe surface of contaminants, calibrate the electrometers, and operate in four different probe biasing modes. iii TABLE OF CONTENTS LIST OF FIGURES.................................................................................................................................................. VI LIST OF TABLES.................................................................................................................................................... IX ACKNOWLEDGMENTS..........................................................................................................................................X 1 INTRODUCTION..............................................................................................................................................1 1.1 OVERVIEW ..................................................................................................................................................1 1.2 DC SHEATHS...............................................................................................................................................2 1.3 THE EARTH’S IONOSPHERE .........................................................................................................................5 1.3.1 Vertical Profile of the Atmosphere ........................................................................................................5 1.3.2 Ionosphere Overview .............................................................................................................................7 1.3.3 Ionization in the Ionosphere ..................................................................................................................8 1.3.4 The Chapman Layers...........................................................................................................................10 1.3.5 Solar Cycle...........................................................................................................................................13 1.3.6 Ionosphere Models...............................................................................................................................13 2 LANGMUIR PROBE THEORY ....................................................................................................................15 2.1 ORBITAL-MOTION-LIMITED THEORY........................................................................................................15 2.1.1 Plasma Parameters..............................................................................................................................15 2.1.2 Current Collection Relationships ........................................................................................................16 2.2 SHEATH THICKNESS ..................................................................................................................................18 2.3 CHILD–LANGMUIR LAW............................................................................................................................23 3 OPERATIONAL MODES ..............................................................................................................................24 3.1 PROBE CLEAN ...........................................................................................................................................25 3.2 ELECTROMETER CALIBRATION..................................................................................................................28 3.3 DC BIAS....................................................................................................................................................28 3.4 PERIODIC SWEPT BIAS...............................................................................................................................29 3.5 ADAPTIVE SWEPT BIAS .............................................................................................................................30 3.6 LOW DATA RATE MODE............................................................................................................................31 4 INSTRUMENT DESIGN ................................................................................................................................34 4.1 INTERFACE DIAGRAMS..............................................................................................................................34 4.1.1 Electrical Interface Diagram...............................................................................................................34 4.1.2 Mechanical Interface Diagram............................................................................................................35 4.2 PROBE AND BOOM DESIGN........................................................................................................................37 4.2.1 Probe Material Composition ...............................................................................................................37 4.2.2 Probe Geometry...................................................................................................................................38 4.2.3 Boom and Probe Fabrication ..............................................................................................................41 4.3 ELECTROMETER ........................................................................................................................................44 4.4 PROBE CLEAN AND CALIBRATION BOARD ................................................................................................47 4.5 CONTROL AND PROCESSING BOARD..........................................................................................................48 4.5.1 Signal Conditioning.............................................................................................................................48 4.5.2 Probe Bias Circuit ...............................................................................................................................53 4.5.3 Microcontroller and Support Hardware Description..........................................................................55 4.5.4 Practical Design Considerations.........................................................................................................62 4.5.5 Board Interfaces ..................................................................................................................................63 4.6 POWER REGULATION BOARD ....................................................................................................................64 4.6.1 Voltage Regulators ..............................................................................................................................65 4.6.2 Filtering ...............................................................................................................................................65 4.6.3 High Voltage Switching Regulator ......................................................................................................67 iv 4.6.4 Power System Protection.....................................................................................................................69 4.6.5 EMC Considerations............................................................................................................................70 4.6.6 Housekeeping.......................................................................................................................................73 4.7 SPACECRAFT CONSTRAINTS ......................................................................................................................77 5 FLIGHT SOFTWARE ....................................................................................................................................79 5.1 SOFTWARE STRUCTURE.............................................................................................................................79
Load more

Recommended publications
  • General Fusion
    General Fusion Fusion Power Associates, 2011 Annual Meeting 1 General Fusion Making commercially viable fusion power a reality. • Founded in 2002, based in Vancouver, Canada • Plan to demonstrate a fusion system capable of “net gain” within 3 years • Industrial and institutional partners including Los Alamos National Lab and the Canadian Government • $32.5M in venture capital, $4.5M in government support Fusion Power Associates, 2011 Annual Meeting 2 General Fusion’s Acoustically Driven MTF Fusion Power Associates, 2011 Annual Meeting 3 Commercialization Advantages Fusion Challenge General Fusion Solution 1.5 m of liquid lead lithium greatly lowers the neutron energy spectrum Neutron activation and embrittlement of structure Low neutron load at the metal wall Low activation Low radiation damage n,2n reaction in lead 4π coverage Tritium breeding Thick blanket High tritium breeding ratio of 1.6 Heat extraction Heat extraction by the working fluid Pb -Li Solubility of tritium in Pb -Li is low Tritium safety 100 M W plant size Low tritium inventory (2g) Pneumatic energy storage >100X lower System cost cost than capacitors Cost of targets in pulsed Liquid metal compression systems - “kopeck” problem No consumables Fusion Power Associates, 2011 Annual Meeting 4 Development Plan 4 years PHASE I Proof of principle Completed 2009 PHASE IIa Construct key components at full scale 2.5 years Prove system can be built $30M Progress to Date Plasma compression tests PHASE II 2012 PHASE IIb 2 years Demonstration of Net Gain Build net gain prototype $35M
    [Show full text]
  • Breakthrough of Inertial Electrostatic Confinement Concept for Advanced Space Propulsion
    69th International Astronautical Congress (IAC), Bremen, Germany, 1-5 October 2018. Copyright ©2018 by the International Astronautical Federation (IAF). All rights reserved. IAC-18,C4,7-C3.5,12,x47993 Breakthrough of Inertial Electrostatic Confinement Concept for Advanced Space Propulsion Y.-A. Chana*, G. Herdricha a Institute of Space Systems, University of Stuttgart, Pfaffenwaldring 29, 70569 Stuttgart, Baden-Wüttemberg, Germany, [email protected] * Corresponding Author Abstract The activities of Inertial electrostatic confinement (IEC) research for propulsion application in IRS started from 2009. A breakthrough on the theoretical explanation of working principle in 2017 IEPC enabled the proof-of-concept of IEC thruster for next generation space exploration. [1] Several advanced IEC propulsion concepts have been proposed accompanying with the working principle which demonstrated a wide-spectrum application from atmosphere-breathing electric propulsion for very-low-earth orbit to fusion propulsion for deep-space manned mission. The SDL can offer both intensive ionization and confinement of ions at the same time which provide the advantage to suppress erosion from ion bombardment. Furthermore, distortion of the SDL by manipulating the applied electric field gradient are the key to achieve plasma extraction from core of IEC. This permits the applications of IEC device goes from neutron generation to electron/ion source, which opens the door to space propulsion. Keywords: (maximum 6 keywords) Nomenclature SDL Spherical double layer – Mass SIE Secondary ion emission particle density SSE Secondary electron emission – Temperature UV Ultra-violet – Velocity VELARC Very-low-power arcjet VLEO Very low earth orbit Acronyms/Abbreviations ABEP Atmosphere-breathing electric 1. Introduction propulsion Inertial electrostatic confinement (IEC) is a device EB Electron beam which was originally designed for fusion application.
    [Show full text]
  • Advancements in Langmuir Probe Diagnostic for Measurements in RF Sheath and in Modelling of the ICRF Slow Wave Mariia Usoltceva
    Advancements in Langmuir probe diagnostic for measurements in RF sheath and in modelling of the ICRF slow wave Mariia Usoltceva To cite this version: Mariia Usoltceva. Advancements in Langmuir probe diagnostic for measurements in RF sheath and in modelling of the ICRF slow wave. Plasma Physics [physics.plasm-ph]. Université de Lorraine; Rijksuniversiteit te Gent, 2019. English. NNT : 2019LORR0061. tel-02970051 HAL Id: tel-02970051 https://hal.univ-lorraine.fr/tel-02970051 Submitted on 17 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. AVERTISSEMENT Ce document est le fruit d'un long travail approuvé par le jury de soutenance et mis à disposition de l'ensemble de la communauté universitaire élargie. Il est soumis à la propriété intellectuelle de l'auteur. Ceci implique une obligation de citation et de référencement lors de l’utilisation de ce document. D'autre part, toute contrefaçon, plagiat, reproduction illicite encourt une poursuite pénale. Contact : [email protected] LIENS Code de la Propriété Intellectuelle. articles
    [Show full text]
  • An Experimental Study of Gridded and Virtual Cathode Inertial Electrostatic Confinement Fusion Systems
    The University of Sydney Doctoral Thesis An Experimental Study of Gridded and Virtual Cathode Inertial Electrostatic Confinement Fusion Systems Author: Supervisor: Richard Bowden-Reid A/Prof. Joseph Khachan A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy in the Department of Plasma Physics and Nuclear Fusion School of Physics September 2019 Declaration of Authorship I, Richard Bowden-Reid, declare that this thesis titled, An Experimental Study of Gridded and Virtual Cathode Inertial Electrostatic Confinement Fusion Systems and the work presented in it are my own. I confirm that: This work was done wholly or mainly while in candidature for a research degree at this University. Where any part of this thesis has previously been submitted for a degree or any other qualification at this University or any other institution, this has been clearly stated. Where I have consulted the published work of others, this is always clearly attributed. Where I have quoted from the work of others, the source is always given. With the exception of such quotations, this thesis is entirely my own work. I have acknowledged all main sources of help. Where the thesis is based on work done by myself jointly with others, I have made clear exactly what was done by others and what I have contributed myself. Sections of Chapter 3 of this thesis are published as: \Evidence for Surface Fusion in Inertial Electrostatic Confinement Devices" Physics of Plasmas, 25, 112702, 2018, https://doi.org/10.1063/1.5053616 I designed the study, analysed the data and wrote the drafts of the manuscript.
    [Show full text]
  • Copyright and Use of This Thesis This Thesis Must Be Used in Accordance with the Provisions of the Copyright Act 1968
    COPYRIGHT AND USE OF THIS THESIS This thesis must be used in accordance with the provisions of the Copyright Act 1968. Reproduction of material protected by copyright may be an infringement of copyright and copyright owners may be entitled to take legal action against persons who infringe their copyright. Section 51 (2) of the Copyright Act permits an authorized officer of a university library or archives to provide a copy (by communication or otherwise) of an unpublished thesis kept in the library or archives, to a person who satisfies the authorized officer that he or she requires the reproduction for the purposes of research or study. The Copyright Act grants the creator of a work a number of moral rights, specifically the right of attribution, the right against false attribution and the right of integrity. You may infringe the author’s moral rights if you: - fail to acknowledge the author of this thesis if you quote sections from the work - attribute this thesis to another author - subject this thesis to derogatory treatment which may prejudice the author’s reputation For further information contact the University’s Copyright Service. sydney.edu.au/copyright A study of scaling physics in a Polywell device Scott Cornish (SID: 306130319) School of Physics University of Sydney Australia A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy (Research) 2016 Declaration of originality I certify that the work presented in this thesis was undertaken solely during my PhD candidature, and has not been presented for any other degree. I certify also that this thesis was written by myself, and that all external contributions and sources have been duly acknowledged.
    [Show full text]
  • Investigation of a Space Propulsion Concept Using Inertial Electrostatic Confinement
    © 2018 Drew Ahern INVESTIGATION OF A SPACE PROPULSION CONCEPT USING INERTIAL ELECTROSTATIC CONFINEMENT BY DREW AHERN DISSERTATION Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Aerospace Engineering in the Graduate College of the University of Illinois at Urbana-Champaign, 2018 Urbana, Illinois Doctoral Committee: Emeritus Professor George H. Miley, Chair Emeritus Professor Rodney L. Burton Assistant Professor Davide Curreli Professor Deborah Levin Professor David N. Ruzic Abstract This thesis discusses the Helicon Injected Inertial Plasma Electrostatic Rocket (HIIPER), a space propulsion concept consisting of a helicon source for plasma generation and an ion extraction method using a nested pair of inertial electrostatic confinement (IEC) grids that are asymmetrically designed. In this study, which used argon as a propellant, a retarding potential analyzer (RPA) was used to measure the exhaust of HIIPER, and results showed the presence of electrons and ions, with ion energies equal to the helicon bias voltage and electron energies on the order of the inner IEC grid voltage. Electron energy distributions were also generated. Quasineutral exhaust conditions were measured to occur with the inner IEC grid between 2 and 3 kV (negative). Tests on the IEC grid configuration were also performed, which indicated that electrons preferentially exited the asymmetry of the inner IEC grid. Langmuir probe measurements showed that some ion losses occurred due to the experimental setup. These losses were reflected in thrust measurements at the exhaust of only a few micronewtons. However, with improvements to the facilities and experimental setup, improvements in thruster efficiency would likely be obtained.
    [Show full text]
  • Inertial Electrostatic Confinement: Theoretical and Experimental Studies of Spherical Devices
    INERTIAL ELECTROSTATIC CONFINEMENT: THEORETICAL AND EXPERIMENTAL STUDIES OF SPHERICAL DEVICES A Dissertation presented to the Faculty of the Graduate School at the University of Missouri-Columbia In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy by RYAN MEYER Dr. Mark Prelas, Dissertation Supervisor Dr. Sudarshan Loyalka, Dissertation Supervisor DECEMBER 2007 The undersigned, appointed by the dean of the Graduate School, have examined the dissertation entitled INERTIAL ELECTROSTATIC CONFINEMENT: THEORETICAL AND EXPERIMENTAL STUDIES OF SPHERICAL DEVICES presented by Ryan Meyer, a candidate for the degree of doctor of philosophy, and hereby certify that, in their opinion, it is worthy of acceptance. Professor Sudarshan Loyalka Professor Mark Prelas Professor Edbertho Leal-Quiros Professor Scott Kovaleski Professor Paul Miceli This is dedicated to my parents, Gerald and Rose, and to my siblings: Vickie, Kevin, Terry, Sheila, Tim, Jill, Darren, and Elizabeth. The support and structure they provided me was instrumental. I wish I could say my motives were pure, but I admit that sibling competitiveness is somewhat responsible for this undertaking. Finally, this dissertation is dedicated to my fiancé Pimphan (Aye) Kiatsimkul. She has been loving, supportive, and motivation for completing this dissertation in a timely fashion. ACKNOWLEDGEMENTS Dr. Mark Prelas and Dr. Sudarshan Loyalka deserve my deepest appreciation for giving me the opportunity to focus my energy on such a fun project. In addition, the rest of the faculty and staff of the Nuclear Science and Engineering Institute deserve similar gratitude for providing the support necessary for me to focus my energy on my technical pursuit. I thank Tushar Ghosh, Robert Tompson, William Miller, and Dabir Viswanath.
    [Show full text]