National Academies Press: OpenBook
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

Thermionics Quo Vadis?

An Assessment of the DTRA’s Advanced Thermionics Research and Development Program

Committee on Thermionic Research and Technology

Aeronautics and Space Engineering Board

Division on Engineering and Physical Sciences

National Research Council

NATIONAL ACADEMY PRESS
Washington, D.C.

Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

NATIONAL ACADEMY PRESS
2101 Constitution Avenue, N.W. Washington, DC 20418

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.

This study was supported by Contract No. DTRA01-00-C-0001 between the National Academy of Sciences and the Defense Threat Reduction Agency. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.

International Standard Book Number: 0-309-08282-X

Available in limited supply from: Aeronautics and Space Engineering Board, HA 292, 2101 Constitution Avenue, N.W., Washington, DC 20418, (202) 334–2855

Additional copies available for sale from:
National Academy Press,
2101 Constitution Avenue, N.W., Box 285, Washington, DC 20055, (800) 624–6242 or (202) 334–3313 (in the Washington metropolitan area), <http://www.nap.edu>

Copyright 2001 by the National Academy of Sciences. All rights reserved.

Printed in the United States of America

Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

THE NATIONAL ACADEMIES

National Academy of Sciences

National Academy of Engineering

Institute of Medicine

National Research Council

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M.Alberts is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Wm.A. Wulf is president of the National Academy of Engineering.

The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine.

The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M.Alberts and Dr. Wm.A. Wulf are chairman and vice chairman, respectively, of the National Research Council.

Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
This page in the original is blank.
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

COMMITTEE ON THERMIONIC RESEARCH AND TECHNOLOGY

TOM MAHEFKEY, Chair, Consultant,

Atlanta, Georgia

DOUGLAS M. ALLEN,*

Schafer Corporation, Dayton, Ohio

JUDITH H. AMBRUS,

Space Technology Management Services, Bridgewater, New Jersey

LEONARD H. CAVENY, Aerospace Consultant,

Fort Washington, Maryland

HAROLD B. FINGER, Consultant,

Chevy Chase, Maryland

GEORGE N. HATSOPOULOS,

Thermo Electron Corporation, Waltham, Massachusetts

THOMAS K. HUNT,

Advanced Modular Power Systems, Inc., Ann Arbor, Michigan

DEAN JACOBSON,

Arizona State University, Tempe, Arizona

ELLIOT B. KENNEL,

Applied Sciences, Inc., Cedarville, Ohio

ROBERT J. PINKERTON,

Spectrum Astro Corporation, Gilbert, Arizona

GEORGE W. SUTTON,

NAE, ANSER Corporation, Arlington, Virginia

Staff

DOUGLAS H. BENNETT, Study Director,

Aeronautics and Space Engineering Board

GEORGE LEVIN, Director,

Aeronautics and Space Engineering Board

ALAN ANGLEMAN, Senior Program Officer

ANNA L. FARRAR, Administrative Associate

BRIDGET EDMONDS (July 2, 2001, until December 27, 2001), Senior Project Assistant

MARY LOU AQUILO (June 12, 2000, until July 2, 2001), Senior Project Assistant

JAN BERGER (September 1, 2001 until October 26, 2001), Project Assistant

VIKTORIA HERSON (January 28, 2000, until June 12, 2000), Project Assistant

*  

The full committee served from April 19, 2000 until December 27, 2001. Mr. Allen served on the com mittee from April 19, 2000, until June 20, 2001.

Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

AERONAUTICS AND SPACE ENGINEERING BOARD

WILLIAM W.HOOVER, Chair,

United States Air Force (retired), Williamsburg, Virginia

A.DWIGHT ABBOTT,

Aerospace Corporation (retired), Los Angeles, California

RUZENA K.BAJSCY,

NAE, IOM, National Science Foundation, Arlington, Virginia

WILLIAM F.BALLHAUS, JR.,

NAE, Aerospace Corporation, Los Angeles, California

JAMES BLACKWELL,

Lockheed Martin Corporation (retired), Marietta, Georgia

ANTHONY J.BRODERICK, Aviation Safety Consultant,

Catlett, Virginia

DONALD L.CROMER,

United States Air Force (retired), Lompoc, California

ROBERT A.DAVIS,

The Boeing Company (retired), Seattle, Washington

JOSEPH FULLER, JR.,

Futron Corporation, Bethesda, Maryland

RICHARD GOLASZEWSKI,

GRA Inc., Jenkintown, Pennsylvania

JAMES M.GUYETTE,

Rolls-Royce North America, Reston, Virginia

FREDERICK H.HAUCK,

AXA Space, Bethesda, Maryland

JOHN L.JUNKINS,

NAE, Texas A&M University, College Station

JOHN K.LAUBER,

Airbus Industrie of North America, Washington, D.C.

GEORGE K.MUELLNER,

The Boeing Company, Seal Beach, California

DAVA J.NEWMAN,

Massachusetts Institute of Technology, Cambridge

JAMES G.O’CONNOR,

NAE, Pratt & Whitney (retired), Coventry, Connecticut

MALCOLM R.O’NEILL,

Lockheed Martin Corporation, Bethesda, Maryland

CYNTHIA SAMUELSON,

Opsis Technologies, Springfield, Virginia

WINSTON E.SCOTT,

Florida State University, Tallahassee

KATHRYN C.THORNTON,

University of Virginia, Charlottesville

ROBERT E.WHITEHEAD,

NASA (retired), Henrico, North Carolina

DIANNE S.WILEY,

The Boeing Company, Long Beach, California

THOMAS L.WILLIAMS,

Northrop Grumman, El Segundo, California

Staff

GEORGE LEVIN, Director

Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

Preface

Generating electricity from a heat source using no moving mechanical parts is the ultimate goal of the Defense Threat Reduction Agency’s thermionics program. However, developing thermionic energy conversion devices has proven difficult, although much progress has been made. In spite of initial success during the late 1960s and intermittent funding since that time, for a variety of reasons no thermionic system has yet been developed in the United States that can be used today on Earth or in space. The ability of human-kind to reach farther and farther into the solar system and beyond is determined, in part, by our ability to generate power in space for spacecraft use.

Thermionic energy conversion has been pursued since the advent of the space age by virtue of its intrinsic attributes as a compact, high performance space power system candidate. While the revolutionary missions that spawned interest in thermionics 40 years ago have yielded to an evolutionary approach to space utilization and exploration, potential future revolutionary missions prompt interest in maintaining and supporting development and examination of this potential technology option today.

Progress in the technology was substantial during the 1960s but waned in the early 1970s due to a shift in space technology funding priorities. The advent of the Strategic Defense Initiative (SDI) and space exploration initiatives in the late 1970s rekindled interest and investment in thermionics. However, that investment diminished again in the mid 1990s, not as a result of lack of progress, but because of changes in national technology investment priorities. Today, the thermionic technology base and infrastructure stand close to extinction. Only a modest $1.5 million to $3 million per year is directed toward sustaining the technology.

Two complete 5 kilowatt-electric nuclear reactor thermionic systems have been developed and flown in space by the former Soviet Union for experimental purposes, but no follow-up Russian or U.S. development on a high power thermionic system has taken place for a variety of reasons. Among them, the political nature of funding priorities involves decisions based on technology considerations, specifically concerning competing technologies that might accomplish the same system-level mission goals as thermionic systems.

The Committee on Thermionic Research and Technology started by asking a difficult question: In light of past efforts and the lack of apparent success in developing a fully functioning system and uncertain requirements, why do thermionics at all? This report is written to answer that question in view of potential future needs and applications while recognizing the existing technological risks as well as the currently available alternative power conversion technologies, in the context of the present, congressionally mandated, DTRA thermionics technology program (see Appendix A for the statement of task).

This study was sponsored by DTRA and was conducted by the Committee on Thermionic Research and Technology appointed by the National Research Council (see Appendix B).

This report has been reviewed by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the authors and the National Research Council in making the published report as sound as possible and to ensure that

Page viii Cite
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. The committee wishes to thank the following individuals for their participation in the review of this report:

Henry W.Brandhorst, Jr., Space Power Institute, Auburn University,

Lee S.Mason, NASA Glenn Research Center,

Gerald D.Mahan, NAS, Applied Physical Sciences, and

Mohamed S.El-Genk, University of New Mexico, Institute for Space and and Nuclear Power Studies.

Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations, nor did they see the final draft of the report before its release.

The review of this report was overseen by Simon Ostrach, Case Western Reserve University. Appointed by the National Research Council, he was responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests entirely with the authoring committee and the institution.

The committee also wishes to thank others whose efforts supported this study, especially those who took the time to participate in committee meetings and the thermionics workshop held in La Jolla, California.

Tom Mahefkey, Chair

Committee on Thermionic Research and Technology

Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×

Tables, Figures, and Boxes

TABLES

ES-1

 

Major Elements of the DTRA Thermionics Program,

 

2

2–1

 

Major Elements of the DTRA Thermionics Program,

 

12

3–1

 

Potential Missions for Solar and Nuclear Thermionic Power Systems,

 

19

3–2

 

Comparison of Flight Demonstrated Power Conversion Technologies,

 

25

3–3

 

Comparison of Ground Demonstrated Power Conversion Technologies,

 

27

3–4

 

Comparison of Projected Power Conversion Technology Capabilities,

 

28

C-1

 

Performance of Chemical and Electrical Propulsion Systems,

 

69

FIGURES

3–1

 

Basic thermionic converter schematic,

 

15

3–2

 

A cross sectional view of a thermionic fuel element (TFE),

 

16

3–3

 

Solar thermionic output voltage based on emitter-collector spacing,

 

17

3–4

 

The current-voltage curve of a typical thermionic converter,

 

18

3–5

 

Power system options for specific mission durations,

 

20

3–6

 

Inverse specific mass versus electrical power output,

 

21

3–7

 

Increase in power density of a nuclear thermionic system as a function of temperature,

 

23

4–1

 

Artist’s rendition of the HPALM solar thermionic concept,

 

36

4–2

 

Artist’s rendition of a solar orbital transfer vehicle,

 

40

5–1

 

Cylindrical inverted multicell cross section,

 

47

5–2

 

Solar energy flux as a function of distance from the Sun,

 

48

7–1

 

Effect of emitter bare work function on performance, using computer code TECMDL,

 

54

7–2

 

Cesiated work function versus bare work function,

 

55

7–3

 

Effects of cesium oxide vapor on converter performance,

 

56

BOXES

3–1

 

Alkali Metal Thermal to Electric Converter,

 

26

4–1

 

The Solar Energy Technology Thermionic Program,

 

41

Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
This page in the original is blank.
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R1
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R2
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R3
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R4
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R5
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R6
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R7
Page viii Cite
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R8
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R9
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R10
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R11
Suggested Citation:"Front Matter." National Research Council. 2001. Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program. Washington, DC: The National Academies Press. doi: 10.17226/10254.
×
Page R12
Next: Executive Summary »
Thermionics Quo Vadis?: An Assessment of the DTRA's Advanced Thermionics Research and Development Program Get This Book
×
Buy Paperback | $47.00 Buy Ebook | $37.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

This report evaluates the Defense Threat Reduction Agency prior and present sponsored efforts; assess the present state of the art in thermionic energy conversion systems; assess the technical challenges to the development of viable thermionic energy conversion systems for both space and terrestrial applications; and recommend a prioritized set of objectives for a future research and development program for advanced thermionic systems for space and terrestrial applications.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!