THE NOVA CONTROL SYSTEM – GOALS, ARCHITECTURE, AND SYSTEM DESIGN*

The Nova laser fusion facility is presently under construction at LLNL. It is a large glass laser, generating 150 trillion watt pulses of infrared light at a wavelength of 1 micrometer (μ). Nova will achieve these energy levels using 10 amplifier chains, each focused onto fusion targets a few millimeters in diameter. Conversion of the 1 μ light to shorter wavelengths of 0.5 μ and 0.35 μ is expected to allow Nova to perform experiments in the physics regime of thermonuclear ignition. The control system for the Nova laser must operate reliably in a harsh pulse power environment and satisfy requirements of technical functionality, flexibility, maintainability and operability. It is composed of four fundamental subsystems: Power Conditioning, Alignment, Laser Diagnostics, and Target Diagnostics, together with a fifth, unifying subsystem called Central Controls. The system architecture utilizes a collection of distributed microcomputers, minicomputers, and components interconnected through high speed fiber optic communications systems. The design objectives, development strategy and architecture of the overall control system and each of its four fundamental subsystems are discussed. Specific hardware and software developments in several areas are also covered.