This book, Vol. No. 7 in the serial publication Physics of Quantum Electronics, contains the proceedings of the 2nd ONR Workshop on Free-Electron Generators of Coherent Radiation held at Telluride, Colorado, 13-17 August, 1979. This recent area of research is now beginning to shape into a new discipline. Free-electron generators of coherent optical radiation are of great interest because of their potential for efficiently producing very high power radiation which in principle is widely tunable from the millimeter to the x-ray region. The book is divided into four sections: tutorial, general interest, variable wigglers, and research interests. The tutorial section includes discussion of the fundamentals of the electron-photon interaction via energy and momentum conservation requirements, laser physics analysis of FEL devices in general, and in the short-pulse domain in particular, and the general problem of efficiency enhancement in the FEL via the variable wiggler technique. The tutorial section concludes with a discussion of Cerenkov and Cerenkov-Raman radiation sources. The general interest section discusses the interaction of electrons at superluminal velocities and their implications for stimulated electromagnetic shock radiation concepts, a coherent pulse treatment of the FEL from the pendulum picture, and various problems associated with the storage ring and numericalmore » simulation of the FEL in single-particle and collective regimes. Electron pre-bunching and klystron-like enhancement of the radiation gain in two-element FELs are discussed. In part three, the variable wiggler concept is discussed, and several different approaches to the problems are presented. Finally, in part four, a broad range of research contributions is presented, from far infrared to possible x-ray production via FEL devices. Of special interest is the possibility of controlling the spread of electron velocities via the transverse gradient in the magnetic wiggler field.« less