The Electra KrF laser program

Electra is a repetitively pulsed, electron-beam pumped, Krypton Fluoride (KrF) laser that will develop the technologies that can meet the Inertial Fusion Energy (IFE) requirements for durability, efficiency, and cost. Electra will have a 30 cm/spl times/30 cm optical aperture, an output of 400-900 Joules, and run at 5 Hz. The main amplifier will be pumped with two 30 cm/spl times/100 cm e-beams, each with V=500 kV, I=110 kA, and t=100 nsec (flat top). The components that need to be developed are: a durable and efficient pulsed power system; a durable electron beam emitter; a long life, transparent pressure foil structure (hibachi); a laser gas recirculator; and long life optical windows. The technologies developed on Electra will be directly scalable to a full size fusion power plant beam line. We have built a first generation pulsed power system that can produce the necessary pulsed power parameters and repetition rate. This system has operated at 5 Hz for 90000 shots (e.g. five hours), which is more than ample to develop the laser components. This paper gives an overview of the Electra program, and then concentrate on the results of our research on electron beam generation, transport, and deposition. This includes evaluation of various cathode and hibachi structures, as well as KrF laser modeling.