High-energy electron beam pumped krypton fluoride (KrF) gas lasers are an attractive choice for inertial fusion energy (IFE). Their short wavelength and demonstrated high beam uniformity optimizes the laser-target physics, and their pulsed power technology scales to a large system. This paper presents the principals of this type of laser and the progress toward developing technologies that can meet the IFE requirements for repetition rate (5 Hz), efficiency (>6%), and durability (>3/spl times/10/sup 8/ shots). The Electra laser at the Naval Research Laboratory (NRL) has produced >500 J of laser light in short 5-Hz bursts. Research on Electra and the NRL Nike laser (3000 J, single shot) has shown that the overall efficiency should be greater than 7%. This is based on recent advances in electron beam stabilization and transport, electron beam deposition, KrF laser physics, and pulsed power. The latter includes the development of a new solid-state laser triggered switch that will be the basis for a pulsed power system that can meet the IFE requirements for efficiency, durability, and cost. The major remaining challenge is to develop long-lived hibachi foils (e-beam transmission windows). Based on recent experiments, this may be achievable by periodically deflecting the laser gas.

Theoretical and experimental research concerning two techniques for transporting intense light ion beams is described. The first technique uses the magnetic field associated with a wall-stabilized z-discharge to radially confine and guide the beam, and the second technique uses the magnetic field from a central current-carrying wire. The ion beam for the experiments is generated and weakly focused onto the aperture of the transport system using a pinch-reflex ion diode on the Naval Research Laboratory Gamble II generator. Typically 1.2-MeV, 100-kA proton beams are transported within radii as small as 1 cm. High-efficiency transport of beams has been demonstrated for both techniques over distances of a few metes. Beam charge and current neutralization were also confirmed. Nuclear diagnostics and shadowboxes were used to measure beam transport efficiency and phase space information for comparison with theoretical predictions. Particle transport efficiencies as high as 100% for the z-discharge technique and 80% for the wire-guided technique were observed.>