Theoretical Analysis of Electron-Beam-Excited KrF Laser Performance: New F₂ Concentration Optimization

For an electron-beam-excited KrF laser, we analyzed theoretically the dependence of the performance characteristics on the excitation rate and initial F₂ concentration. According to the analysis of KrF* formation processes, KrF* relaxation processes, 248 nm absorption processes, and their individual efficiencies, a novel optimization method for initial F₂ concentrations is necessary instead of a conventional method of a “constant” F₂ burn-up rate. Then, we determined optimum F₂ concentration as a function of the excitation rate for excitation pulses of 20–500 ns FWHM. Finally, we obtained the scaling law for the intrinsic KrF laser efficiency.