Advanced Lasers for Fusion Applications

Abstract

Advanced Lasers subsystems performance requirements for a fusion power reactor are presented and analyzed in the context of an energy-storage laser medium. Three types of energy-storing laser media are identified: 1) the Group VI atoms, 2) selected rare-earth doped solids, and 3) rare-earth molecular gases. The operating principles, basic parameters, and conceptual designs for high energy amplifiers are outlined for 1) atomic selenium pumped photolytically with rare-gas excimer radiation, 2) thulium-doped glass pumped with XeF excimer radiation, and 3) terbium chelate vapor pumped with KrF excimer radiation. The use of energy nonstoring laser media, particularly the rare-gas monohalide excimers, are discussed in the context of short-pulse fusion applications. The concept of backward wave Raman pulse compression is introduced as one attractive means toward this end. The basic parameters and a conceptual design of a KrF pumped methane (CH4 ) Raman compressor laser are presented. On the basis of exploratory experiments and computer modeling of amplifier devices and systems, all of the systems discussed here appear scientifically and technologically scalable in energy to hundreds of kilojoules. Systems efficiencies are projected to be in the range of 1-5%, subject to favorable resolution of a few remaining physics and technological issues.