Development of an Electron-Beam-Pumped High-Power KrF Laser as a Short-Pulse Amplifier

Two modules of a low impedance electron-beam (e-beam) machine were developed to pump a 200-J, 70-ns KrF laser from both sides. The laser was designed as the power amplifier of a picosecond, terawatt excimer laser system, which will be applied to a basic physical research on extreme ultraviolet lasers. Each driving circuit of the e-beam diode was a 2.8.-Ω double parallel plate Blumlein with a 500-kV rail gap as the main switch. The energy deposited in the 42-ℓ laser gain region was measured by several diagnostics to determine the energy transfer efficiency and the spatial uniformity of energy deposition with the guide magnetic field of 1 kG. The triggered operation of 500-kV rail gaps, which is essential for amplifier system synchronization, was realized by the ultraviolet laser irradiation along the rail-gap axis with reduced switching time and jitter of 20 and 1.9 ns, respectively.