Multi-MJ KrF laser driver for a 2050 IFE reactor

A new design of a multi-megajoule KrF laser driver for the Prometheus inertial fusion energy (IFE) reactor c. year 2050 has been developed exploiting advances achieved in nonlinear optics (NLO) during the past decade. Optimized excimer e-beam sustained electric-discharge lasers are predicted to produce output energies too low with pulses too long to meet IFE target irradiation requirements. The NLO devices used in this design permit the independent optimization of excimer laser modules while providing the important functions of coherent beam combination, intensity smoothing, and temporal pulse compression at high efficiencies. The KrF driver utilizes a modularized architecture consisting of 2160 excimer laser pumps coherently combined into 60 beam smoothing Raman accumulators and subsequently pulse-compressed in electronically seeded stimulated Brillouin scattering cells, with the resultant 60 output beams delivering 5 MJ of ultraviolet laser energy to the direct drive target in a ramped 6-ns pulse. Techniques proposed achieve ±1% spatial and temporal target illumination uniformities. Emphasis on safety and reliability in this design permits the KrF laser driver to tolerate periodic component failures without precipitating reactor shutdowns