Atomic Oxygen Line Shape Measurement at 130 nm with Raman-Shifted Laser

摘要

The absorption of vacuum ultraviolet light by atomic oxygen has been measured in the electric arc-driven shock tube facility at NASA Ames Research Center. A probe beam is generated with a Raman-shifted ArF excimer laser. By suitable tuning of the laser, absorption is measured over a range of wavelengths in the region of the ~3P_1-~3S~0 line at 130.49 nm. The Lorentzian full width at half-height due to collision broadening by atomic oxygen is measured at various wavelengths up to 1200 linewidths away from the line center. The measured linewidth is three times larger than that calculated with an established radiation code, and a possible explanation for the difference is discussed. This experiment demonstrates the viability of high-order Raman shifters as light sources in impulse facilities where singnal averaging is not possible.