Das Energiespektrum der Elektronen beim Betazerfall war lange Zeit umstritten. 1914 fand Chadwick Hinweise auf ein kontinuierliches Energiespektrum, doch seine Ergebnisse wurden nicht allgemein anerkannt. Chadwick und Ellis lernten einander in einem deutschen Internierungslager wahrend des 1. Weltkriegs kennen. Ellis gelang im Jahre 1927 der endgultige Beweis fur das kontinuierliche Spektrum. Damit war der Weg frei fur Paulis Neutrino-Hypothese und fur die Fermi-Theorie der schwachen Wechselwirkung. In Streuexperimenten mit Alphateilchen fanden Rutherford, Chadwick und andere ab 1920 Hinweise auf eine bis dahin unbekannte Kernkraft, die wir heute als starke Wechselwirkung bezeichnen. Die Entdeckung des Neutrons durch Chadwick im Jahre 1932 war ein entscheidender Beitrag zum Verstandnis beider Kernkrafte. Die Biografien der beiden Physiker werden beleuchtet.

You cannot hide from radioactivity. Even the book you are holding is slightly radioactive, but there are more serious risks. Radioactivity - the breakdown of unstable atomic nuclei, releasing radiation - is a fundamental process in nature. It is a process that has been harnessed to provide wide and important applications in science, medicine, industry, and energy production. But it remains much misunderstood - and feared, perhaps because nuclear radiation cannot be detected by human senses, and can undoubtedly do great harm if appropriate precautions are not taken. In recent times there have been increasing concerns about nuclear terrorism. The traces of radioactive atoms in rocks have allowed us to understand the nature and history of the Earth, in particular to date events in that history. Radioactive dating has been used for a variety of purposes, from determining the age of the first hominids to the dating of the Turin Shroud. The discovery of radioactivity has improved our survival kit, but also gave us the chance to reach a new level of awareness on the history of our species and its environmental impacts. In this Very Short Introduction, Claudio Tuniz explains the nature of radioactivity and discuss its role in nature. Describing radioactivity in the stars and in the Earth, he also looks at its wide range of applications in biomedicine and in science, as well as the mechanisms of nuclear fission and fusion, and the harnessing of nuclear power. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.

Since the development of natural philosophy in Ancient Greece, scientists have been concerned with determining the nature of matter's smallest constituents and the interactions among them. This textbook examines the question of the microscopic composition of matter through an accessible introduction to what is now called 'The Physics of Elementary Particles'. In the last few decades, elementary particle physics has undergone a period of transition, culminating in the formulation of a new theoretical scheme, known as 'The Standard Model', which has profoundly changed our understanding of nature's fundamental forces. Rooted in the experimental tradition, this new vision is based on geometry and sees the composition of matter in terms of its accordance with certain geometrical principles. This textbook presents and explains this modern viewpoint to a readership of well-motivated undergraduate students, by guiding the reader from the basics to the more advanced concepts of Gauge Symmetry, Quantum Field Theory and the phenomenon of spontaneous symmetry breaking through concrete physical examples. This engaging introduction to the theoretical advances and experimental discoveries of the last decades makes this fascinating subject accessible to undergraduate students and aims at motivating them to study it further.

Nuclear physics began long before the identification of fundamental particles, with J. J. Thomson's discovery of the electron at the end of the 19th century, which implied the existence of a positive charge in the atom to make it neutral. In this Very Short Introduction Frank Close gives an account of how this area of physics has progressed, including the recognition of how heavy nuclei are built up in the cores of stars and in supernovae, the identification of quarks and gluons, and the development of quantum chromodynamics (QCD). Exploring key concepts such as the stability of different configurations of protons and neutrons in nuclei, Frank Close shows how nuclear physics brings the physics of the stars to Earth and provides us with important applications, particularly in medicine. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.

This text is a comprehensive, balanced and up-to-date introduction to nuclear physics that describes the experiments made to study nuclear reactions and nuclear structure, and the theories and models that have been developed to understand the properties of nucleic and their interactions. After a historical introduction, there are chapters on: nuclear accelerators and detectors; elementary particles; nuclear forces; nuclear reaction theory; nuclear models; nuclear and heavy ion reactions; nuclear astrophysics; and nuclear reactors. While primarily aimed at undergraduates it will also serve as a reference for graduate students and professional nuclear physicists.

There are fundamental relations between three vast areas of physics: particle physics, cosmology and condensed matter physics. The fundamental links between the first two areas, in other words, between micro- and macro- worlds, have been well established. There is a unified system of laws governing the scales from subatomic particles to the Cosmos and this principle is widely exploited in the description of the physics of the early Universe. The main goal of this book is to establish and define the connection of these two fields with condensed matter physics. According to the modern view, elementary particles (electrons, neutrinos, quarks, etc.) are excitations of a more fundamental medium called the quantum vacuum. This is the new 'aether' of the 21st Century. Electromagnetism, gravity, and the fields transferring weak and strong interactions all represent different types of the collective motion of the quantum vacuum. Among the existing condensed matter systems, a quantum liquid called superfluid 3He-A most closely represents the quantum vacuum. Its quasiparticles are very similar to the elementary particles, while the collective modes of the liquid are very similar to electromagnetic and gravitational fields, and the quanta of these collective modes are analogues of photons and gravitons. The fundamental laws of physics, such as the laws of relativity (Lorentz invariance) and gauge invariance, arise when the temperature of the quantum liquid decreases. This book is written for graduate students and researchers in all areas of physics.

The Black Book of Quantum Chromodynamics is an in-depth introduction to the particle physics of current and future experiments at particle accelerators. The book offers the reader an overview of practically all aspects of the strong interaction necessary to understand and appreciate modern particle phenomenology at the energy frontier. It assumes a working knowledge of quantum field theory at the level of introductory textbooks used for advanced undergraduate or in standard postgraduate lectures. The book expands this knowledge with an intuitive understanding of relevant physical concepts, an introduction to modern techniques, and their application to the phenomenology of the strong interaction at the highest energies. Aimed at graduate students and researchers, it also serves as a comprehensive reference for LHC experimenters and theorists. This book offers an exhaustive presentation of the technologies developed and used by practitioners in the field of fixed-order perturbation theory and an overview of results relevant for the ongoing research programme at the LHC. It includes an in-depth description of various analytic resummation techniques, which form the basis for our understanding of the QCD radiation pattern and how strong production processes manifest themselves in data, and a concise discussion of numerical resummation through parton showers, which form the basis of event generators for the simulation of LHC physics, and their matching and merging with fixed-order matrix elements. It also gives a detailed presentation of the physics behind the parton distribution functions, which are a necessary ingredient for every calculation relevant for physics at hadron colliders such as the LHC, and an introduction to non-perturbative aspects of the strong interaction, including inclusive observables such as total and elastic cross sections, and non-trivial effects such as multiple parton interactions and hadronization. The book concludes with a useful overview contextualising data from previous experiments such as the Tevatron and the Run I of the LHC which have shaped our understanding of QCD at hadron colliders.

In the 1920s, when quantum mechanics was in its infancy, chemists and solid state physicists had little choice but to manipulate unwieldy equations to determine the properties of even the simplest molecules. When mathematicians turned their attention to the equations of quantum mechanics, they discovered that these could be expressed in terms of group theory, and from group theory it was a short step to operator methods. This important development lay largely dormant until this book was originally published in 1963. In this pathbreaking publication, Brian Judd made the operator techniques of mathematicians comprehensible to physicists and chemists. He extended the existing methods so that they could handle heavier, more complex molecules and calculate their energy levels, and from there, it was another short step to the mathematical analysis of spectra. This book provides a first-class introduction to continuous groups for physicists and chemists. Although first written from the perspective of atomic spectroscopy, its major topics and methods will appeal to anyone who has an interest in understanding particle theories of nuclear physics. Originally published in 1998. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

A clear and well-organized review of what is presently known about nuclear structure. Emphasis is less upon mathematical detail than upon the obtaining of a clear perspective which relates the various lines of approach to this complex and rapidly developing field. Particular attention is paid to nuclear models and to the several types of nuclear reactions. Originally published in 1958. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

There have been many demonstrations, particularly for magnetic impurity ions in crystals, that spin-Hamiltonians are able to account for a wide range of experimental results in terms of much smaller numbers of parameters. Yet they were originally derived from crystal field theory, which contains a logical flaw; electrons on the magnetic ions are distinguished from those on the ligands. Thus there is a challenge: to replace crystal field theory with one of equal or greater predictive power that is based on a surer footing. The theory developed in this book begins with a generic Hamiltonian, one that is common to most molecular and solid state problems and that does not violate the symmetry requirements imposed on electrons and nuclei. Using a version of degenerate perturbation theory due to Bloch and the introduction of Wannier functions, projection operators, and unitary transformations, Stevens shows that it is possible to replace crystal field theory as a basis for the spin-Hamiltonians of single magnetic ions and pairs and lattices of magnetic ions, even when the nuclei have vibrational motion. The power of the method is further demonstrated by showing that it can be extended to include lattice vibration and conduction by electron hopping such as probably occurs in high-Tc superconductors. Thus Stevens shows how an apparently successful ad hoc method of the past can be replaced by a much more soundly based one that not only incorporates all the previous successes but appears to open the way to extensions far outside the scope of the previously available methods. So far only some of these have been explored. The book should therefore be of great interest to all physicists and chemists concerned with understanding the special properties of molecules and solids that are imposed by the presence of magnetic ions. Originally published in 1997. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

Der Pauli-Briefwechsel ist eine der wichtigsten Quellen zur Geschichte der Physik des 20. Jahrhunderts. Fur diesen ersten Teilband wurden zunachst 430 Briefe aus den Jahren 1950 - 1952 ausgewahlt. Sie dokumentieren neben der physikalischen Grundlagenforschung die ideengeschichtlichen Probleme dieser Zeit. UEber das rein historische Interesse hinausgehend wird der Leser zur Reflexion uber die Grenzen unseres gegenwartigen naturwissenschaftlichen Weltbildes angeregt. Ein Standardwerk fur jeden, der sich ernsthaft mit der Geschichte der Physik auseinandersetzt.

Jurgen Beetz zeigt zuerst den Ursprung der erdachten Geschichten der Physik aus der Steinzeit, denn vieles ist so einfach, dass es schon Steinzeitmenschen hatten verstehen koennen. Im Anschluss daran erklart der Autor den Aufbau von Atomen und sagt etwas zu ihren physikalischen Groessen aus. Obwohl "Atom" eigentlich "unteilbar" bedeutet, bestehen Atome dennoch aus Teilen - dies erlautert er im Weiteren genau. Schliesslich bespricht er die geheimnisvollen "Quanten" und ihr merkwurdiges Verhalten.

Die beruhmte Vorlesung von Freeman Dyson - nun erstmals auf Deutsch. In den 1940er Jahren zeigte Freeman Dyson die Aquivalenz zwischen den beiden Formulierungen der QED - des Pfadintegralansatzes von Richard Feynman und der Variationsmethoden von Julian Schwinger - und bewies somit die Konsistenz der QED. Dieses Buch beinhaltet die wertvollen - nie zuvor auf Deutsch publizierten - Vorlesungen uber Quantenfeldtheorie, die Dyson an der Cornell Universitat 1951 gehalten hat.

Der Theoretiker Edwin Thompson Jaynes bemerkte dazu: "Fur eine Generation von Physikern waren diese Vorlesungen ein Gewinn: klarer und besser motiviert als Feynmans Vorlesungen, und schneller und kompakter als Schwingers." Zukunftige Leser werden diese Vorlesungen ebenfalls mit grossem Genuss lesen und von dem klaren Stil profitieren, der fur Dyson stets so charakteristisch gewesen ist.

Aus dem Inhaltsverzeichnis: 1 - Die Diracgleichung, 2 - Streuprobleme und die Born-Approximation, 3 - Die klassische und quantenmechanische Feldtheorie, 4 - Beispiele quantisierter Feldtheorien (Maxwellfeld, Diracelektronen), 5 - Streuprobleme freier Teilchen (Paar Annihilation, Moller-Streuung, Klein-Nishina-Formel), 6 - Allgemeine Theorie der Streuung (Feynman-Graphen, Infrarotkatastrophe), 7 - Streuung an einem statischen Potenzial und experimentelle Ergebnisse.

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Questo volume raccoglie le lezioni del Corso di Radioattivita impartite, inizialmente dall autore e successivamente da suoi collaboratori, agli studenti di Fisica presso l Universita di Pavia. I temi trattati costituiscono un introduzione ai fenomeni radioattivi in senso stretto con escursioni, aventi come base di partenza e filo conduttore il decadimento beta, nel campo della fisica delle particelle elementari, in particolare dei neutrini, e dell astrofisica. Alcuni argomenti sono tradizionali, altri riguardano la fisica di frontiera cosi che al lettore sono offerti particolari itinerari dalla fisica consolidata alla fisica in evoluzione. Ovviamente, per quanto riguarda quest ultima, i risultati sperimentali riportati e i relativi commenti hanno carattere di provvisorieta. Per questa ragione, in questa edizione del testo, e stata rivolta particolare attenzione all aggiornamento dei risultati relativi allo studio dei neutrini nell ambito del doppio decadimento beta e delle oscillazioni di neutrino. In ogni caso, gli argomenti discussi rappresentano una scelta, per qualche verso arbitraria, del vasto materiale disponibile e vengono proposti con carattere introduttivo e non esaustivo. La comprensione dei vari temi presuppone il possesso delle nozioni normalmente impartite nei primi tre anni del Corso di Laurea in Fisica."

The second edition of an established graduate text, this book complements the material for a typical advanced graduate course in quantum mechanics by showing how the underlying classical structure is reflected in quantum mechanical interference and tunnelling phenomena, and in the energy and angular momentum distributions of quantum mechanical states in the moderate to large (10-100) quantum number regime. Applications include accurate quantization techniques for a variety of tunnelling and curve-crossing problems and of non-separable bound systems; direct inversion of molecular scattering and spectroscopic data; wavepacket propagation techniques; and the prediction and interpretation of elastic, inelastic and chemically reactive scattering. The main text concentrates less on the mathematical foundations than on the global influence of the classical phase space structures on the quantum mechanical observables. Further mathematical detail is contained in the appendices and worked problem sets are included as an aid to the student.

Plasmaphysik gibt eine systematische Einfuhrung in die Methoden zur theoretischen Beschreibung physikalischer Prozesse in ionisierten Gasen. Ausgehend vom mikroskopischen Teilchenbild werden die Gleichungen sowohl fur eine mikroskopische als auch fur eine makroskopische Beschreibung eines Plasmas abgeleitet. Soweit es ohne groesseren mathematischen Aufwand moeglich ist, werden relativistische Effekte berucksichtigt. Besonders diskutiert wird die Frage, welche Naherung welcher Fragestellung angemessen ist. Als Beispiele werden Fragestellungen aus der Astrophysik, der Magnetospharenphysik, sowie Laborexperimente diskutiert. Insbesondere werden Gleichgewichtskonfigurationen, Instabilitaten und Wellen in den verschiedenen Naherungen behandelt.

Das Buch bietet eine an der Praxis ausgerichtete Einfuhrung in den Strahlenschutz und seine physikalischen Grundlagen. Anhand von Beispielen, Ubungsaufgaben und einfachen Experimenten behandelt der Autor die biologische Strahlenwirkung und Quellen der Strahlenbelastung ebenso wie Messmethoden und Fragen der praktischen Umsetzung des Strahlenschutzes. Die vierte Auflage wurde auf den neuesten Stand der Technik gebracht und durch Kapitel uber Kernkraftwerke, Strahlungsquellen und die Effekte nicht-ionisierender Strahlung erganzt. "

Der Autor prasentiert eine neue Theorie der Reduktion physikalischer Theorien, die durch einfache Beispiele aus der Physik erlautert wird. Neuartig daran ist, dass sie nicht einen ein fur alle Mal verbindlichen, allgemeinen Reduktionsbegriff zugrunde legt, sondern einen auf der Hintereinanderschaltung von Reduktionen rekursiven Aufbau gibt, bei dem alle Reduktionen als Kombinationen moglichst spezieller elementarer Reduktionen erscheinen. Die Theorienreduktion aus dem Bereich der Relativitatstheorie, der Quantentheorie und der Thermodynamik wird in einem Folgeband behandelt. Dieses systematisch angelegte Buch richtet sich an Leser, die an Wissenschaftstheorie interessiert sind, aber auch an Physiker ohne vertiefte philosophische Vorkenntnisse."

Was ist Strahlenschutz, wie gefahrlich sind Strahlen? Die Autoren informieren verstandlich uber Fakten, Hypothesen und gesetzliche Grenzwerte. Sie setzen bewusst keine Kenntnisse der Physik, Biologie oder Medizin voraus. Das Buch ist fur alle die geschrieben, die wissen mochten, was hinter dem Begriff "Strahlenschutz" steckt. Der Erfolg dieses Buches hat gezeigt, wie dringend notwendig eine sachliche Information uber die Strahlen- und Strahlenschutzproblematik ist. Gerade die Meinungsbildner, Lehrer und Arzte, sind gefordert, die Frage nach den Gefahren einer Kerntechnik auch quantitativ korrekt zu beantworten. Dies gilt besonders in einer Zeit, in der nach einem GAU in Tschernobyl und Vorwurfen gegen die Atomindustrie in der Tagespresse die Kernenergie politisch vertretbar erscheint. Beide Autoren gehoren zu der kleinen Gruppe hauptberuflicher Strahlenschutzer. Sie sind Mitglieder nationaler und internationaler Kommissionen, in denen die Grenzwerte diskutiert und Empfehlungen beschlossen werden. Die 3. Auflage des Bu- ches berucksichtigt die Grenzwertempfehlungen der ICRP (Internationale Kommission fur Strahlenschutz) von 1990 im Arbeitsschutz und fur die Bevolkerung. Sie wurden geandert, als neue Untersuchungen eine tatsachlich niedrigere Strahlendosis in Hiroshima und Nagasaki ergaben. Damit erleben die Untersuchungen der Krebssterbefalle an Uberlebenden der Atombombenabwurfe eine neue Bewertung.

Vorliegendes Buch gibt den Inhalt unserer zweisemestrigen Vor- lesung in Kernchemie und Radiochemie an der hiesigen Technischen Hochschule wieder. Der entsprechende Unterricht galt ursprunglich Horern der Fachabteilungen Chemie, Elektrizitatslehre und Mechanik sowie Medizinern der hiesigen Universitat, hat sich aber in den letzten Jahren hauptsachlich auf Chemiker und Technische Physiker be- schrankt. Der Mangel an zusammenfassenden Darstellungen des umfangreichen Gebietes in einer Schrift fuhrte zunachst zu einem Manuskript in schwe- discher Sprache, dann zur Dbersetzung ins Deutsche. Seit der Fertig- stellung des ursprunglichen Manuskriptes hat sich der Mangel an deutsch- sprachiger Literatur auf unserem Arbeitsgebiet verringert [so sind u. a. inzwischen Bucher uber die kernchemischen Grundlagen, uber die Ana- lyse des zu radiochemischen Trennungen so oft verwendeten Ionenaus- tauschverfahrens, uber Einzelheiten der Kernbrennstoffaufbereitung und uber die Berucksichtigung des Strahlenschutzes bei Arbeiten mit hochradioaktiven Stoffen erschienen, vgl. Literaturhinweise Kap. 1-3: 4, Kap. 7: 20 und Kap. 9: 9 und 14]. Dennoch haben wir von dem ursprunglichen Plan einer zusammen- fassenden Darstellung nicht Abstand genommen, da wir es fur wesent- lich halten, den Studierenden eine im Umfang noch einigermaBen leicht zu bewaltigende Einfiihrung in das gesamte Fachgebiet in die Hande zu geben. Die Form einer Einfuhrung fuhrt mit sich, daB wir von dem ublichen System der Literaturhinweise in Form von Zitaten Abstand nehmen. Jedoch erwies es sich als zweckmaBig, zumindest die Namen einiger Verfasser an den entsprechenden Textstellen zu erwahnen. (Bei der gedrangten Auswahl sind moglicherweise fiihrende Forscher un- genugend oder uberhaupt nicht erwahnt worden.

8 dabei so klein wie nur moeglich gehalten. Durch Gegenuberstellung mit den jeweiligen klassischen Vorstellungen wird der spezifisch quantenmechanische, unanschauliche Charakter der quanten- mechanischen Naturbeschreibung hervorgehoben, der gerade in den Eigenschaften des Photons so deutlich zum Ausdruck kommt. Unter diesem Aspekt, so scheint mir, koennte das Buchlein auch helfen, das Verstandnis der Prinzipien der' Quantenmechanik zu vertiefen. Ich setze beim Leser nur Kenntnis der klassischen Elektrodyna- mik und eine gewisse Vertrautheit mit den Grundzugen der Quan- tentheorie voraus, wie sie im ersten Teil einer ublichen Quanten- mechanikvorlesung vermittelt wird. Interessierte Leser, die mir gern die eine oder die andere Frage stellen moechten oder sich zu kritischen Bemerkungen herausge- fordert fuhlen, moechte ich ausdrucklich dazu ermuntern, mit mir in einen Gedankenaustausch zu treten. Zum Schluss bedanke ich mich sehr herzlich bei meinen Kollegen Dr. TH. RICHTER und Dr. H. STEUDEL fur viele klarende Diskus- sionen und zahlreiche nutzliche Hinweise. Mein besonderer Dank gilt Herrn Prof. Dr. G. WEBER, Jena, fur eine sehr sorgfaltige Durchsicht des Manuskripts.