The Advanced Research Workshop (ARW) on Condensed Matter Re search Using Neutrons, Today and Tomorrow was held in Abingdon, Oxfordshire for four days beginning 26 March 1984. The Workshop was sponsored by NATO and the Rutherford Appleton Laboratory. A total of 32 lecturers and participants attended. An objective of the Workshop was to review some dynamic proper ties of condensed matter that can be studied using neutron spectros copy. A second objective, no less important, was to identify new topics that might be investigated with advanced spallation neutron sources. The twelve lectures reproduced in this volume bear wit ness, largely by themselves, to the success of the Workshop in meet ing these objectives. The many discussions generated by lecturers and participants meant that, in the event, the objectives were in deed amply satisfied. I should like to thank all those who attended the Horkshop for their part in making it so beneficial and rewarding. I am most grateful to Reinhard Scherm, who acted as my advisor in the organisation of the Workshop. The efforts of Mrs. M. Sherwen and Miss J. Harren made light my burden of administrative duties. The preparation of the manuscript for publication was simplified by the assistance of Miss C. Monypenny."

Application of quantum mechanics in physics and chemistry often entails manipulation and evaluation of sums and products of coupling coefficients for the theory of angular momentum. Challenges encountered in such work can be tamed by graphical techniques that provide both the insight and analytical power. The book is the first step-by-step exposition of a graphical method grounded in established work. Copious exercises recover standard results but demonstrate the power to go beyond.

An international workshop on Elementary Excitations and Fluctuations in Magnetic Systems was held in Turin for five days beginning 25 May, 1987. The workshop followed much the same format as the one with the same title held in San Miniato in 1984 (proceedings: Springer Series in-Solid-State Sciences, Vol. 54), that most participants contributed talks and provided papers for the proceedings. While many of the participants had attended the first workshop, 15 of the 40 invited review papers were presented by scientists who had not. The majority of the talks reported theoretical work concerned with the introduction of new techniques. However, experimental work was also well represented, not least because many of the reported theoretical studies were motivated by experimental findings, and a highlight of the workshop was an extremely stimulating session devoted to recent neutron scattering measure- ments, on various systems, that exploited polarization analysis. The fine venue of the workshop, Villa Gualino, with its excellent facili- ties and spacious accommodation, helped to produce a delightful relaxed and friendly atmosphere. For the use of Villa Gualino and significant financial support we are indebted to our host organization, the Institute for Scien- tific Interchange (lSI). Additional financial support came from the Consiglio Nazionale delle Ricerche (CNR), Centro Interuniversitario di Struttura della Material del Ministero della Pubblica Istruzione (CISM-MPI) and Gruppo Nazionale di Struttura della Materia (GNSM-CNR).

Application of quantum mechanics in physics and chemistry often entails manipulation and evaluation of sums and products of coupling coefficients for the theory of angular momentum. Challenges encountered in such work can be tamed by graphical techniques that provide both the insight and analytical power. The book is the first step-by-step exposition of a graphical method grounded in established work. Copious exercises recover standard results but demonstrate the power to go beyond.

The Advanced Research Workshop (ARW) on Condensed Matter Re search Using Neutrons, Today and Tomorrow was held in Abingdon, Oxfordshire for four days beginning 26 March 1984. The Workshop was sponsored by NATO and the Rutherford Appleton Laboratory. A total of 32 lecturers and participants attended. An objective of the Workshop was to review some dynamic proper ties of condensed matter that can be studied using neutron spectros copy. A second objective, no less important, was to identify new topics that might be investigated with advanced spallation neutron sources. The twelve lectures reproduced in this volume bear wit ness, largely by themselves, to the success of the Workshop in meet ing these objectives. The many discussions generated by lecturers and participants meant that, in the event, the objectives were in deed amply satisfied. I should like to thank all those who attended the Horkshop for their part in making it so beneficial and rewarding. I am most grateful to Reinhard Scherm, who acted as my advisor in the organisation of the Workshop. The efforts of Mrs. M. Sherwen and Miss J. Harren made light my burden of administrative duties. The preparation of the manuscript for publication was simplified by the assistance of Miss C. Monypenny."

An invaluable, up-to-date reference aid for investigators and researchers, this two-volume work develops the principles and concepts of statistical physics and quantum chemistry that are the basis for the interpretation of experimental data. These volumes build on the author's now standard text, Theory of Neutron Scattering (OUP, 1971), and include expanded coverage of nuclear scattering, with many sections completely rewritten and updated, and many previously unpublished experimental calculations. With a greatly expanded bibliography including 200 new references, this work will interest graduate students and researchers in physics.

The techniques of magnetic neutron and photon scattering provide information on the electronic properties of materials that is obtainable in no other way. With both techniques information on an atomic scale is obtained on the spatial and temporal developments of the spin and current densities which are fundamental quantities in a basic understanding of magnetic phenomena. To date most magnetic scattering studies have used neutron beams, and the use of photon beams is, relatively speaking, in its infancy. This book is the first monograph devoted to the theory required for a full interpretation of magnetic scattering experiments. It is designed to meet the needs of postgraduates and researchers new to the techniques. At the same time, the requirements of theoretical chemists and physicists are catered for through chapters that present the basic formalism in detail. Special features of the book include extensive tables of quantities that occur frequently in applications of theory, and a number of worked examples.