Abstract

Considerable cost savings will be achieved for the 2.2-MJ, 192-beam National Ignition Facility (NIF) laser by grouping many beams into bundles passing through a common multi-amplifier box. Grouping amplifier chains together reduces building space requirements, reduces the number of internal amplifier parts, and increases pumping efficiency. In the current NIF design, 8 beam lines are arranged in a 4-beam high by 2-beam wide matrix. Each beam must pass through 19 amplifiers. Because of the beam grouping and pulsed-power considerations, the NIF flashlamps will have 4.3-cm bore diameters and 180-cm arc lengths, much larger than the flashlamps used in previous ICF laser systems. The NIF flashlamps will nominally operate at 20% of the single-shot explosion energy and 360-μs pulsewidth. At this operating point a NIF flashlamp must dissipate 34 kilojoules of electrical energy while the peak current is 28 kiloamperes. Altogether, some 9120 such flashlamps will be used. These flashlamps must operate reliably and with high electrical-to-optical radiant conversion efficiency for the NIF to meet requirements for laser energy, operating costs, and availability.

© 1996 Optical Society of America