There have been two major review articles on the iodine laser in the last ll seven years, liThe Photochemical Iodine Laser by K. Hohla and K. Kompa (Handbook of Chemical Lasers, edited by R. Gross and J. Bott, Wi 1 ey, New York,1976) and a SANDIA report (No. 78-1071, 1978) entitled liThe Atomic Iodine Laserll. Since then, a large body of new material has been published, and practical experience has been gained with large iodine laser systems in Garchi ng (ASTERIX II I) and in the USSR. These 1 asers have now become very reliable tools, especially in fusion-oriented plasma experiments, which represent their main field of application. They can deliver powers in excess of many terawatts per beam and are thus also suited for use in other areas such as X-ray lasers, incoherent X-ray sources, compression of matter and its behaviour at very high densities. The physics of the iodine laser is now rather well understood, and its technology has reached a standard adequate for the construction of large scale systems in the multi-hundred kJ range. In view of this new situation, we thought it useful to document the present state of the art ina book. Its contents and the literature cited therein have been chosen to cover those areas which are of main concern in the design and operation of pulsed high-power iodine lasers.

The High-Power Lasers and Applications Conference was held in Munich, June 20 - 22, 1977. The conference took place simultaneously with the "Laser 77, International Congress and Trade Fair" at the Munich Fair Ground. The meeting was a continuation of a series of colloquia on elec tronic transition lasers previously held in the United States. The main topics of the conference were: high-power VUV, UV, visible and IR la sers, including an analysis of laser systems, technology and laser con cepts. Also, some applications to nonlinear optics, chemical kinetics and spectroscopy, particularly with respect to isotope separation, were discussed. The conference was attended by 95 scientists representing Austria, Canada, England, Finland, Germany (FRG), Germany (GDR), France, Israel, Italy, The Netherlands, and the U.S.A. The organizers acknowledge financial support from the Deutsche Forschungs gemeinschaft, the U.S. Air Force Office of Scientific Research, the U.S. Air Force European Office of Aerospace Research and Development (EOARD) and the U.S. Army European Research Office, as well as from the companies Coherent Radiation, Spectra Physics and Cryophysics. Furthermore, we thank our colleagues Dr. Steven N. Suchard and Professor Jeffrey I. Steinfeld for coordinating the U.S. contribution to the conference. We are grateful to Frau Maischberger for administrative assistance.

In the thirty years since the invention of the CO2 gas laser, the major design issue has shifted from how to obtain the desired power level to how to achieve reliable operation. At the same time, the opening of many laser development facilities in the Former Soviet Union has allowed their achievements and design approaches to be understood and appreciated for the first time. Further, the industrial laser user community has identified a number of emerging applications at higher power levels (15-20 kW) than are attainable by most commercial devices. In High Power Lasers - Science and Engineering, the designers, developers and users of high-power gas laser systems discuss design approaches, methods of enhancing performance, new applications, and user requirements.

Since the third Workshop on "Laser Interaction and Related Plasma Phenomena" in 1973, one area within the scope of this con ference received increased attention: laser fusion. This possi bility was emphasized in February 1977 in a Seminar on US energy policies at The Hartford Graduate Center by John F. O'Leary, Head of the Federal Energy Administration, who said that "by the year 2100, ••• laser fusion will be coming along, giving us a new age of choice". Efforts in research and development were stepped up to investigate new concepts of laser ignition of controlled nuclear reactions. Here, one expects no radioactive waste from fuel. Th~ deuterium-tritium reaction - the only one which may be possible with magnetic field confinement in tokamaks - has a highly radio active tritium cycle, while, in principle, laser reactions are possible with pure deuterium, hydrogen-boron or others. The worldwide progress in laser compression was not only stim ulated by the energy crisis, but also by its advancements. In our first Workshop in 1969 F. Floux of the French Limeil Laboratories described his experiments, which led, only one month later, to the production of fusion neutrons in such large numbers as had not been achieved up to then (see appendix of Vol. I these Proceedings).