A description of Target Area systems performance shows that the target area conceptual design can meet its performance criteria. Before the shot, the target area provides a vacuum of 5 [times] 10[sup [minus]5] Torr within 2 hours. A target, cryogenic or non-cryogenic, is placed to within 1 cm of chamber center with a positioner that minimizes vibration of the target. The target is then aligned to [le] 7 [mu]m by using the Target Alignment Sensor (TAS) system. The viewers in this system will also determine if the target is ready for illumination. Diagnostics are aligned to the necessary specifications by the alignment viewers. The target is shot and data is collected. Nearly all tritium (if present) is passed through the vacuum system and into the collection system. The analysis that supports the target area design basis is a combination of careful assumptions, data, and calculations. Some uncertainty exists concerning certain aspects of the source terms for x-rays and debris, material responses to this energy flux, and the full consequences of the material responses that do occur. For this reason, we have selected what we believe are conservative values in these areas. Advanced conceptual design activities will improve our understanding of these phenomena and allow a more quantitative assessment of the degree of conservatism inherent to the system. However, the results of this preliminary survey of target area operations indicate an annual shot rate of 600 (for the mix of shots shown in Table 1) is feasible for this set of target area systems.

The Target Area Structural Support (TASS) systems are designed to provide an optically stable support for the target area systems and personnel access platforms for the 192 laser beam configuration. The conceptual design of the TASS systems was an optimum configuration selected from three designs on which performance studies were conducted. The supporting bases for the design selection were the analytical results, operation, and cost effective.

The preliminary design of the target area for the National Ignition Facility has been completed. The target area is required to meet a challenging set of engineering system design requirements and user needs. The target area must provide the appropriate conditions before, during, and after each shot. The repeated introduction of large amounts of laser energy into the chamber and subsequent target emissions represent new design challenges for ICF facility design. Prior to each shot, the target area must provide the required target illumination, target chamber vacuum, diagnostics, and optically stable structures. During the shot, the impact of the target emissions on the target chamber, diagnostics, and optical elements is minimized and the workers and public are protected from excessive prompt radiation doses. After the shot, residual radioactivation is managed to allow the required accessibility. Diagnostic data is retrieved, operations and maintenance activities are conducted, and the facility is ready for the next shot. The target area subsystems include the target chamber, target positioner, structural systems, target diagnostics, environmental systems, and the final optics assembly. The engineering design of the major elements of the target area requires a unique combination of precision engineering, structural analysis, opto-mechanical design, random vibration suppression, thermal stability, materials engineering, robotics, and optical cleanliness. The facility has been designed to conduct both x- ray driven targets and to be converted at a later date for direct drive experiments. The NIF has been configured to provide a wide range of experimental environments for the anticipated user groups of the facility. The design status of the major elements of the target area is described.