Electron beam pumped KrF lasers for fusion driver

A basic module for large scale KrF laser amplifiers having four electron beam diodes has been developed in order to confirm the scalability of KrF lasers. The KrF laser module produces 580J output in 100ns pulse duration with high intrinsic efficiency around 10%. The experimental results are consistent with the prediction based on calculations using the 3D ASE code. The criterion for the high efficiency operation of high power KrF lasers is defined as g0D≤3 and g0L = 10 in double pass configurations. According to the pump rate scaling, high efficiency operation of the high pump rate KrF laser module gives the conclusion that high power output of 500kJ will be delivered from a large scale amplifier having a large active volume of 60m3 excited by long pulse electron beams. (author)