Electra: Repetitively Pulsed 700 J, 100 ns Electron Beam Pumped KrF Laser

This paper presents a brief overview of the Electra laser system and report on the most recent results. The laser system consists of an electron beam pumped main amplifier with an aperture of 30times30 cm 2 , an e-beam pumped 10times10 cm 2 pre-amplifier, and a commercial discharge laser serving as the seed oscillator. The main amplifier, currently operated as an oscillator, has demonstrated single shot and rep-rate laser energies exceeding 700 J, with a pulse width of 100 ns at 248 nm. Continuous operation of this laser in an oscillator mode has lasted for more than 2.5 hours without failure at 1 and 2.5 Hz. Tests at higher repetition rates and longer runs are ongoing. The pre-amplifier uses a fast gas Marx, pulse forming lines, a single stage magnetic switch, and transit time isolators and operates with a rep-rate of up to 5 Hz.