Fundamentals in Nuclear Physics The Ecole Polytechnique, one of France’s top academic institutions, has a long- standing tradition of producing exceptional scientific textbooks for its students. The original lecture notes, the Cours de l’Ecole Polytechnique, which were written by Cauchy and Jordan in the nineteenth century, are considered to be landmarks in the development of mathematics. The present series of textbooks is remarkable in that the texts incorporate the most recent scientific advances in courses designed to provide undergraduate students with the foundations of a scientific discipline. An outstanding level of quality is achieved in each of the seven scientific fields taught at the Ecole: pure and applied mathematics, mechanics, physics, chemistry, biology, and econom- ics. The uniform level of excellence is the result of the unique selection of aca- demic staff there which includes, in addition to the best researchers in its own renowned laboratories, a large number of world-famous scientists, appointed as part-time professors or associate professors, who work in the most advanced research centers France has in each field. Another distinctive characteristics of these courses is their overall consistency; each course makes appropriate use of relevant concepts introduced in the other textbooks. This is because each student at the Ecole Polytechnique has to acquire basic knowledge in the seven scientific fields taught there, so a substantial link between departments is necessary. The distribution of these courses used to be restricted to the 900 students at the Ecole. Some years ago we were very success- ful in making these courses available to a larger French-reading audience. We now build on this success by making these textbooks also available in English. Jean-Louis Basdevant James Rich Michel Spiro Fundamentals In Nuclear Physics From Nuclear Structure to Cosmology With 184 Figures Prof. Jean-Louis Basdevant Dr. James Rich Ecole Polytechnique Dapnia-SPP De´partement de Physique CEA-Saclay Laboratoire Leprince-Ringuet 91191 Gif-sur-Yvette 91128 Palaiseau France France [email protected] [email protected] Dr. Michel Spiro IN2P3-CNRS 3 Rue Michel-Ange 75794 Paris cedex 16 France [email protected] Cover illustration: Background image—Photograph of Supernova 1987A Rings. Photo credit Chris- topher Burrows (ESA/STScI) and NASA, Hubble Space Telescope, 1994. Smaller images, from top to bottom—Photograph of Supernova Blast. Photo credit Chun Shing Jason Pun (NASA/GSFC), Robert P. Kirshner (Harvard-Smithsonian Center for Astrophysics), and NASA, 1997. Interior of the JET torus. Copyright 1994 EFDA-JET. See figure 7.6 for further description. The combustion chamber at the Nova laser fusion facility (Lawrence Livermore National Laboratory, USA). Inside the combustion chamber at the Nova laser fusion facility (Lawrence Livermore National Labora- tory, USA) The Euratom Joint Research Centres and Associated Centre. Library of Congress Cataloging-in-Publication Data Basdevant, J.-L. (Jean-Louis) Fundamentals in nuclear physics / J.-L. Basdevant, J. Rich, M. Spiro. p. cm. Includes bibliographical references and index. ISBN 0-387-01672-4 (alk. paper) 1. Nuclear physics. I. Rich, James, 1952– II. Spiro, M. (Michel) III. Title. QC173.B277 2004 539.7—dc22 2004056544 ISBN 0-387-01672-4 Printed on acid-free paper. ©2005 Springer Science+Business Media, Inc. All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, Inc., 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, com- puter software, or by similar or dissimilar methodology now known or hereafter developed is for- bidden. The use in this publication of trade names, trademarks, service marks and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed in the United States of America. (EB) 987654321 SPIN 10925645 springeronline.com Preface Nuclear physics began one century ago during the “miraculous decade” be- tween 1895 and 1905 when the foundations of practically all modern physics were established. The period started with two unexpected spinoffs of the Crooke’s vacuum tube: Roentgen’s X-rays (1895) and Thomson’s electron (1897), the first elementary particle to be discovered. Lorentz and Zeemann developed the the theory of the electron and the influence of magnetism on radiation. Quantum phenomenology began in December, 1900 with the ap- pearance of Planck’s constant followed by Einstein’s 1905 proposal of what is now called the photon. In 1905, Einstein also published the theories of relativity and of Brownian motion, the ultimate triumph of Boltzman’s sta- tistical theory, a year before his tragic death. For nuclear physics, the critical discovery was that of radioactivity by Becquerel in 1896. By analyzing the history of science, one can be convinced that there is some rationale in the fact that all of these discoveries came nearly simul- taneously, after the scientifically triumphant 19th century. The exception is radioactivity, an unexpected baby whose discovery could have happened sev- eral decades earlier. Talented scientists, the Curies, Rutherford, and many others, took the ob- servation of radioactivity and constructed the ideas that are the subject of this book. Of course, the discovery of radioactivity and nuclear physics is of much broader importance. It lead directly to quantum mechanics via Rutherford’s planetary atomic model and Bohr’s interpretation of the hydrogen spectrum. This in turn led to atomic physics, solid state physics, and material science. Nuclear physics had the important by-product of elementary particle physics and the discovery of quarks, leptons, and their interactions. These two fields are actually impossible to dissociate, both in their conceptual and in their experimental aspects. The same “magic decade” occurred in other sectors of human activity. The second industrial revolution is one aspect, with the development of radio and telecommunications. The automobile industry developed at the same period, with Daimler, Benz, Panhard and Peugeot. The Wright brothers achieved a dream of mankind and opened the path of a revolution in transportation. Medicine and biology made incredible progress with Louis Pasteur and many others. In art, we mention the first demonstration of the “cin´ematographe” VI Preface by Auguste and Louis Lumi`ere on december 28 1895, at the Grand Caf´e, on Boulevard des Capucines in Paris and the impressionnist exhibition in Paris in 1896. Nowadays, is is unthinkable that a scientific curriculum bypass nuclear physics. It remains an active field of fundamental research, as heavy ion accelerators of Berkeley, Caen, Darmstadt and Dubna continue to produce new nuclei whose characteristics challenge models of nuclear structure. It has major technological applications, most notably in medicine and in en- ergy production where a knowledge of some nuclear physics is essential for participation in decisions that concern society’s future. Nuclear physics has transformed astronomy from the study of planetary trajectories into the astrophysical study of stellar interiors. No doubt the most important result of nuclear physics has been an understanding how the ob- served mixture of elements, mostly hydrogen and helium in stars and carbon and oxygen in planets, was produced by nuclear reactions in the primordial universe and in stars. This book emerged from a series of topical courses we delivered since the late 1980’s in the Ecole Polytechnique. Among the subjects studied were the physics of the Sun, which uses practically all fields of physics, cosmology for which the same comment applies, and the study of energy and the environ- ment. This latter subject was suggested to us by many of our students who felt a need for deeper understanding, given the world in which they were going to live. In other words, the aim was to write down the fundamentals of nuclear physics in order to explain a number of applications for which we felt a great demand from our students. Such topics do not require the knowledge of modern nuclear theory that is beautifully described in many books, such as The Nuclear Many Body Problem by P. Ring and P Schuck. Intentionally, we have not gone into such developments. In fact, even if nuclear physics had stopped, say, in 1950 or 1960, practically all of its applications would exist nowadays. These appli- cations result from phenomena which were known at that time, and need only qualitative explanations. Much nuclear phenomenology can be under- stood from simple arguments based on things like the Pauli principle and the Coulomb barrier. That is basically what we will be concerned with in this book. On the other hand, the enormous amount of experimental data now easily accesible on the web has greatly facilitated the illustration of nuclear systematics and we have made ample use of these resources. This book is an introduction to a large variety of scientific and techno- logical fields. It is a first step to pursue further in the study of such or such an aspect. We have taught it at the senior undergraduate level at the Ecole Polytechnique. We believe that it may be useful for graduate students, or more generally scientists, in a variety of fields. In the first three chapters, we present the “scene” , i.e. we give the basic notions which are necessary to develop the rest. Chapter 1 deals with the Preface VII basic concepts in nuclear physics. In chapter 2, we describe the simple nu- clear models, and discuss nuclear stability. Chapter 3 is devoted to nuclear reactions. Chapter 4 goes a step further. It deals with nuclear decays and the fun- damental electro-weak interactions.