Laser‐fusion devices at Livermore and Rochester use Nd glass

Fusion research with solid‐state lasers entered a higher‐power regime recently as the Lawrence Livermore Laboratory began operating its 20‐beam, 20–30 terawatt $(1012 watts)$ neodymium–glass laser system. The design and current status of the facility were described by the associate director of Livermore, John L. Emmett, and others at the Conference on Laser and Electro‐Optical Systems held in San Diego in February. After having successfully fired all twenty arms of the system at 10 kilojoules with a pulse of 1 nanosec, the Livermore group was changing the configuration for shorter (down to 0.1 ns) pulses, installing the final pieces of diagnostics and hardware, and aligning the lasers on a target in groups of five. A photograph of the target chamber appears on the cover of this issue of PHYSICS TODAY. The power of 1.7 TW attained by the first beam had confirmed hopes that all twenty beams would collectively reach the upper limit of the design power.