System description and initial performance results for beamlet

The Department of Energy has proposed to design and construct a National Ignition Facility (NIF) for Inertial Confinement Fusion (ICF) research. This facility will contain a frequency-tripled, Nd:Glass laser system capable of irradiating fusion targets at an energy and power of 1.8 MJ and 500 TW. The laser output pulse contains most of the energy, where the low-intensity leading foot is 15-20 ns long and the final high-intensity pulse is 3-4 ns long. The laser will have 192 independent {open_quotes}beamlets,{close_quotes} each having a final square clear aperture of 40 x 40 cm{sup 2} and an output beam area slightly smaller than the clear aperture. A Conceptual Design Report (CDR), prepared in May 1994, discusses the laser and facility design in detail. The authors have constructed and are now testing a scientific prototype of a single beamlet of the proposed NIF laser. The purpose of these tests is to show that the novel features proposed for the NIF laser design will perform as projected and that the laser is ready for final engineering design. The final dimensions and component arrangements for NIF will differ somewhat from the scientific prototype, but the differences are sufficiently small that tests on the prototype canmore » be used to demonstrate performance essentially equivalent to a NIF beamlet.« less