ELECTRA: AN ELECTRON BEAM PUMPED KrF REP-RATE LASER SYSTEM FOR INERTIAL FUSION ENERGY

Electra is a high average power KrF laser system at the Naval Research Laboratory funded under the HAPL program. The goal of Electra is to develop the laser driver technologies needed, for an inertial fusion energy power plant. When run in an oscillator configuration the 500 kV, 100 kA e-beam pumped main amplifier produces 730 J with a 100 ns pulse width at 248 nm. KrF lasers have been shown to have intrinsic efficiencies of 12% leading to a projected wall plug efficiency of > 7% for an IFE system with demonstrated improvements in laser physics and pulse power technologies. As an oscillator the Electra main amplifier has run continuously at 1 Hz, 2.5 Hz, and 5 Hz for multi-thousand shot runs. This paper will discuss recent results from Electra including operation as a complete laser amplifier system, first demonstration of a new method to efficiently cool the hibachi foil with indications of a reduced penalty in laser uniformity, and design modifications to increase durability. Work sponsored by the US Department of Energy, NNSA/DP.