Magnetohydrodynamics, or MHD, is a theoretical way of describing the statics and dynamics of electrically conducting uids. The most important of these uids occurring in both nature and the laboratory are ionized gases, called plasmas. These have the simultaneous properties of conducting electricity and being electrically charge neutral on almost all length scales. The study of these gases is called plasma physics. MHD is the poor cousin of plasma physics. It is the simplest theory of plasma dynamics. In most introductory courses, it is usually afforded a short chapter or lecture at most: Alfven waves, the kink mode, and that is it. (Now, on to Landau damping ) In advanced plasma courses, such as those dealing with waves or kinetic theory, it is given an even more cursory treatment, a brief mention on the way to things more profound and interesting. (It is just MHD Besides, real plasma phy- cists do kinetic theory ) Nonetheless, MHD is an indispensable tool in all applications of plasma physics."

This book gives a concise description of the phenomenon of plasma relaxation from the point of view of resistive magnetohydrodynamic (MHD) theory. Magnetized plasmas relax when they seek their natural state of lowest energy subject to certain topological constraints imposed by the magnetic field. Relaxation may be fast and dynamic or slow and gradual depending on the external environment in which the magnetoplasma system evolves. Relaxation occurs throughout the universe and may describe such diverse phenomena as dynamos, solar flares, and the operation of magnetic fusion energy experiments. This book concentrates on the dynamic, rather than variational aspects of relaxation. While the processes described are general, the book focuses on the reversed-field pinch experiment as a paradigm for plasma relaxation and dynamo action. Examples from other branches of plasma physics are also discussed. The authors draw upon their extensive experience in numerical and experimental studies of relaxation.

Magnetohydrodynamics, or MHD, is a theoretical way of describing the statics and dynamics of electrically conducting uids. The most important of these uids occurring in both nature and the laboratory are ionized gases, called plasmas. These have the simultaneous properties of conducting electricity and being electrically charge neutral on almost all length scales. The study of these gases is called plasma physics. MHD is the poor cousin of plasma physics. It is the simplest theory of plasma dynamics. In most introductory courses, it is usually afforded a short chapter or lecture at most: Alfven waves, the kink mode, and that is it. (Now, on to Landau damping ) In advanced plasma courses, such as those dealing with waves or kinetic theory, it is given an even more cursory treatment, a brief mention on the way to things more profound and interesting. (It is just MHD Besides, real plasma phy- cists do kinetic theory ) Nonetheless, MHD is an indispensable tool in all applications of plasma physics."