ADVANCES IN IMAGING AND ELECTRON PHYSICS VOLUME 149 ELECTRON EMISSION PHYSICS EDITOR-IN-CHIEF PETER W. HAWKES CEMES-CNRS Toulouse, France HONORARY ASSOCIATE EDITORS TOM MULVEY BENJAMIN KAZAN Advances in Imaging and Electron Physics Electron Emission Physics BY KEVIN L. JENSEN Electronics Science and Technology Division Naval Research Laboratory Washington, DC VOLUME 149 AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Academic Press is an imprint of Elsevier 525 B Street, Suite 1900, San Diego, California 92101-4495, USA 84 Theobald’s Road, London WC1X 8RR, UK This book is printed on acid-free paper. Copyright ß 2007, Elsevier Inc. All Rights Reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the Publisher. The appearance of the code at the bottom of the first page of a chapter in this book indicates the Publisher’s consent that copies of the chapter may be made for personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay the stated per copy fee through the Copyright Clearance Center, Inc. (www.copyright.com), for copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. Copy fees for pre-2007 chapters are as shown on the title pages. If no fee code appears on the title page, the copy fee is the same as for current chapters. 1076-5670/2007 $35.00 Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone: (þ44) 1865 843830, fax: (þ44) 1865 853333, E-mail:
[email protected] You may also complete your request on-line via the Elsevier homepage (http://elsevier.com), by selecting ‘‘Support & Contact’’ then ‘‘Copyright & Permission’’ and then ‘‘Obtaining Permissions.’’ For all information on all Elsevier Academic Press publications visit our Web site at www.books.elsevier.com ISBN: 978-0-12-374207-0 PRINTED IN THE UNITED STATES OF AMERICA 07 08 09 10 9 8 7 6 5 4 3 2 1 In memory of William D. Jensen (July 16, 1938 – July 4, 2007) for his inspirational devotion to science This page intentionally left blank CONTENTS Dedication . . . . . . Preface . . . . . . . Future Contributions Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v ix xi xvii