At the time that we decided to begin work on this book, several other volumes on the free-electron laser had either been published or were in press. The earliest work of which we were aware was published in 1985 by Dr T. C. Marshall of Columbia University [1]. This book dealt with the full range of research on free-electron lasers, including an overview of the extant experiments. However, the field has matured a great deal since that time and, in our judgement, the time was ripe for a more extensive work which includes the most recent advances in the field. The fundamental work in this field has largely been approached from two distinct and, unfortunately, separate viewpoints. On the one hand, free-electron lasers at sub-millimetre and longer wavelengths driven by low-energy and high-current electron beams have been pursued by the plasma physics and microwave tube communities. This work has confined itself largely to the high-gain regimes in which collective effects may play an important role. On the other hand, short-wavelength free-electron lasers in the infrared and optical regimes have been pursued by the accelerator and laser physics community. Due to the high-energy and low-current electron beams appropriate to this spectral range, these experiments have operated largely in the low-gain single-particle regimes. The most recent books published on the free-electron laser by Dr C. A.

The 22nd International Free Electron Laser Conference and 7th FEL User Workshop were held August 13-18, 2000 at Washington Duke Inn and Golf Club in Durham, North Carolina, USA. The conference and the workshop were hosted by Duke University's Free Electron laser (FEL) Laboratory. Following tradition, the FEL prize award was announced at the banquet. The year 2000 FEL prize was awarded to three scientists propelling the limits of high power FELs: Steven Benson, Eisuke Minehara and George Neill. The conference program was comprised of traditional oral sessions on First Lasing, FEL theory, storage ring FELs, linac and high power FELs, long wavelength FELs, SASE FELs, accelerator and FEL physics and technology, and new developments and proposals. Two sessions on accelerator and FEL physics and technology reflected the emphasis on the high quality of accelerators and components for modern FELs. The breadth of the applications was presented in the workshop oral sessions on materials processing, biomedical and surgical applications, physics and chemistry as well as on instrumentation and methods for FEL applications. A special oral session was dedicated to FEL center status reports for users to learn more about the opportunities with FELs. As usual, the oral sessions were supplemented by poster sessions with in-depth discussions and communications. The FEL physicists and FEL users had excellent opportunities to interact throughout the duration of the event, culminating a Joint Sessions. The year 2000 was very successful being marked by lasing with two SASE and one storage ring short-wavelength FELs, and by the first human surgery with the use of FEL, to mention but a few. The International Program Committee and chairs of the sessions had the challenging and exciting problem of selecting invived and contributed talks for the conferences and the workshop from the influx of abstracts mentioning new results and ideas. The success of the conference was determined by these contributions. Scientists from 15 countries gave 70 talks, presented 176 posters and submitted 146 papers, which are published in the present volume of proceedings.

This book contains the Proceedings of the 24th International Free Electron Laser Conference and the 9th Free Electron Laser Users Workshop, which were held on September 9-13, 2002 at Argonne National Laboratory. Part I has been reprinted from Nucl. Instr. and Meth. A 507 (2003), Nos. 1-2.

This volume contains Part II of the proceedings of the conference on Free Electron Lasers, held in Beijing, August 1997. Part I appears in a special issue of Nuclear Instruments and Methods A.The last 20 years has seen different stages of FEL development. In these proceedings the reader will find descriptions of many new facilities, new experimental results, new applications, new theoretical developments and new simulation results. Attention is also focussed on the recent progress in experimental observations SASE. The contributions are from 150 scientists from 13 countries, ensuring broad, up-to-date research results from a dynamic field.