Electromagnetic Radiation: Variational Methods, Waveguides and Accelerators

Julian Schwinger was already the world's leading nuclear theorist when he joined the Radiation Laboratory at MIT in 1943, at the ripe age of 25. Just 2 years earlier he had joined the faculty at Purdue, after a postdoc with OppenheimerinBerkeley,andgraduatestudyatColumbia. Anearlysemester at Wisconsin had con?rmed his penchant to work at night, so as not to have to interact with Breit and Wigner there. He was to perfect his iconoclastic 1 habits in his more than 2 years at the Rad Lab. Despite its deliberately misleading name, the Rad Lab was not involved in nuclear physics, which was imagined then by the educated public as a esoteric science without possible military application. Rather, the subject at hand was the perfection of radar, the beaming and re?ection of microwaves which had already saved Britain from the German onslaught. Here was a technology which won the war, rather than one that prematurely ended it, at a still incalculable cost. It was partly for that reason that Schwinger joined this e?ort, rather than what might have appeared to be the more natural project for his awesome talents, the development of nuclear weapons at Los Alamos. He had got a bit of a taste of that at the Metallurgical Laboratory in Chicago, and did not much like it. Perhaps more important for his decision to go to and stay at MIT during the war was its less regimented and isolated environment.

Contains unpublished material by the late Julian Schwinger (Nobel Prize 1965)

Texte du rabat
The present volume comprehensively summarizes the late Julian Schwinger's work on the theory of electromagnetic radiation and its application to waveguides, transmission lines, accelerator physics and synchrotron radiation. The first part, written in textbook style, has
grown out of lectures and manuscripts by Julian Schwinger prepared during the war at MIT's Radiation Laboratory, updated with material developed by Schwinger at UCLA in the 1970s and 1980s, and by Milton at the University of Oklahoma since 1994. The second part consists of reprints of more than 15 papers (some of them never published or available with very limited circulation) by Schwinger on these topics. This volume will be of great interest to physicists, electrical engineers and applied mathematicians
whether they be students or seasoned professionals. A paperback study edition of the first part is available separately.

Contenu
A Treatise on Radiation Theory.- Maxwell's Equations.- Spherical Harmonics.- Relativistic Transformations.- Variational Principles for Harmonic Time Dependence.- Transmission Lines.- Waveguides and Equivalent Transmission Lines.- Rectangular and Triangular Waveguides.- Electromagnetic Fields in Waveguides with Circular Cross Sections.- Reflection and Refraction.- Variational Methods.- Examples of Variational Calculations for Circular Guide.- Steady Currents and Dissipation.- The Impedance Concept in Waveguides.- Accelerators: Microtrons and Synchrotrons.- Synchrotron Radiation.- Diffraction.- Quantum Limitations on Microwave Oscillators.- Relevant Papers of Julian Schwinger.- On the Representation of the Electric and Magnetic Fields Produced by Currents and Discontinuities in Wave Guides. I.- Electron Orbits in the Synchrotron.- On Radiation by Electrons in a Betatron.- On the Classical Radiation of Accelerated Electrons.- The Quantum Correction in the Radiation by Energetic Accelerated Electrons.- Classical Radiation of Accelerated Electrons. II. A Quantum Viewpoint.- Classical and Quantum Theory of Synergic Synchrotron-?erenkov Radiation.- New Approach to Quantum Corrections in Synchrotron Radiation.- On the Radiation of Sound from an Unflanged Circular Pipe.- On the Theory of Diffraction by an Aperture in an Infinite Plane Screen. I.- On the Theory of Diffraction by an Aperture in an Infinite Plane Screen. II..- On the Transmission Coefficient of a Circular Aperture.- On the Theory of Electromagnetic Wave Diffraction by an Aperture in an Infinite Plane Conducting Screen.