WAVE TURBULENCE is a state of a system of many simultaneously excited and interacting waves characterized by an energy distribution which is not in any sense close to thermodynamic equilibrium. Such situations in a choppy sea, in a hot plasma, in dielectrics under arise, for example, a powerful laser beam, in magnets placed in a strong microwave field, etc. Among the great variety of physical situations in which wave turbulence arises, it is possible to select two large limiting groups which allow a detailed analysis. The first is fully developed wave turbulence arising when energy pumping and dissipation have essentially different space scales. In this case there is a wide power spectrum of turbulence. This type of turbulence is described in detail e. g. in Zakharov et al. 1 In the second limiting case the scales in which energy pumping and dissipation occur are the same. As a rule, in this case a narrow, almost singular spectrum of turbulence appears which is concentrated near surfaces, curves or even points in k-space. One of the most important, widely investigated and instructive examples of this kind of turbulence is parametric wave turbulence appearing as a result of the evolution of a parametric instability of waves in media under strong external periodic modulation (laser beam, microwave electromagnetic field, etc. ). The present book deals with parametric wave turbulence.

This much-needed book addresses the concepts, models, experiments and applications of magnons and spin wave in magnetic devices. It fills the gap in the current literature by providing the theoretical and technological framework needed to develop innovative magnetic devices, such as recording devices and sensors. Starting with a historical review of developments in the magnon concept, and including original experimental results, the author presents methods of magnon excitation, and several basic models to describe magnon gas. He includes experiments on Bose-Einstein condensation of non-equilibrium magnons, as well as various applications of a magnon approach.

MODERN FERRITES, Volume 1 A robust exploration of the basic principles of ferrimagnetics and their applications In Modern Ferrites Volume 1: Basic Principles, Processing and Properties, renowned researcher and educator Vincent G. Harris delivers a comprehensive overview of the basic principles and ferrimagnetic phenomena of modern ferrite materials. Volume 1 explores the fundamental properties of ferrite systems, including their structure, chemistry, and magnetism; the latest in processing methodologies; and the unique properties that result. The authors explore the processing, structure, and property relationships in ferrites as nanoparticles, thin and thick films, compacts, and crystals and how these relationships are key to realizing practical device applications laying the foundation for next generation technologies. This volume also includes: Comprehensive investigation of the historical and scientific significance of ferrites upon ancient and modern societies; Neel’s expanded theory of molecular field magnetism applied to ferrimagnetic oxides together with theoretic advances in density functional theory; Nonlinear excitations in ferrite systems and their potential for device technologies; Practical discussions of nanoparticle, thin, and thick film growth techniques; Ferrite-based electronic band-gap heterostructures and metamaterials. Perfect for RF engineers and magnetitians working in the field of RF electronics, radar, communications, and spintronics as well as other emerging technologies. Modern Ferrites will earn a place on the bookshelves of engineers and scientists interested in the ever-expanding technologies reliant upon ferrite materials and new processing methodologies. Modern Ferrites Volume 2: Emerging Technologies and Applications is also available (ISBN: 9781394156139).

Wave Turbulence refers to the statistical theory of weakly nonlinear dispersive waves. There is a wide and growing spectrum of physical applications, ranging from sea waves, to plasma waves, to superfluid turbulence, to nonlinear optics and Bose-Einstein condensates. Beyond the fundamentals the book thus also covers new developments such as the interaction of random waves with coherent structures (vortices, solitons, wave breaks), inverse cascades leading to condensation and the transitions between weak and strong turbulence, turbulence intermittency as well as finite system size effects, such as “frozen” turbulence, discrete wave resonances and avalanche-type energy cascades. This book is an outgrow of several lectures courses held by the author and, as a result, written and structured rather as a graduate text than a monograph, with many exercises and solutions offered along the way. The present compact description primarily addresses students and non-specialist researchers wishing to enter and work in this field.

(Cont.) Investigated in this thesis are the excitation and observation of Langmuir wave turbulence caused by the parametric decay instability (PDI) in high-frequency space plasma heating experiments conducted at the NSF/DoD High Frequency Active Auroral Research Program (HAARP) facility in Gakona, Alaska during the spring and summer of 2006. The PDI is the decay of an electromagnetic (EM) wave into an electron plasma wave (i.e., Langmuir wave) and an ion acoustic wave. When the excited Langmuir wave parametrically decays into another Langmuir and ion acoustic wave pair, a cascade of Langmuir waves can occur provided that the instability threshold is satisfied. According to recently advanced theory by Kuo and Lee [2005], there are two possible methods of cascade: non-resonant and resonant. While the non-resonant cascade proceeds at the location of excitation, the resonant process occurs at lower altitudes to minimize losses that the non-resonant process incurs by remaining at the excitation altitude. Such losses are caused by the frequency mismatch effect, as the decay ion acoustic wave frequency becomes much less than that of the normal ion acoustic waves. In their downward propagation the Langmuir waves in the resonant cascade suffer from propagation losses, however these losses are less than those associated with the non-resonant process. The resonant process is therefore expected to have a lower threshold. Theoretical claims and calculations are compared to observations made at Arecibo, Puerto Rico and Tromso, Norway. Claims are also are supported by incoherent backscatter radar observations made at the HAARP facility in Gakona.

This book presents recent scientific achievements in the investigation of magnetization dynamics in confined magnetic systems. Introduced by Bloch as plane waves of magnetization in unconfined ferromagnets, spin waves currently play an important role for description of very small systems.Spin wave confinement effect was experimentally discovered in the 1990s in permalloy microstripes. The diversity of systems where this effect is observed has been steadily growing since then, most of which will be addressed in this book. The book includes six chapters which originate from different groups of experimentalists and theoreticians dominating the field since the discovery of the effect. Different chapters of the book reflect different facets of spin wave confinement, providing a comprehensive description of the effect and its place in modern magnetism. It will be of value for scientists and engineers working on magnetic storage elements and magnetic logic, and is also suitable as an advanced textbook for graduate students.

By bringing together various ideas and methods for extracting the slow manifolds, the authors show that it is possible to establish a more macroscopic description in nonequilibrium systems. The book treats slowness as stability. A unifying geometrical viewpoint of the thermodynamics of slow and fast motion enables the development of reduction techniques, both analytical and numerical. Examples considered in the book range from the Boltzmann kinetic equation and hydrodynamics to the Fokker-Planck equations of polymer dynamics and models of chemical kinetics describing oxidation reactions. Special chapters are devoted to model reduction in classical statistical dynamics, natural selection, and exact solutions for slow hydrodynamic manifolds. The book will be a major reference source for both theoretical and applied model reduction. Intended primarily as a postgraduate-level text in nonequilibrium kinetics and model reduction, it will also be valuable to PhD students and researchers in applied mathematics, physics and various fields of engineering.