Abstract: A method and system are provided for determining temperature of a low density gas seeded with molecules of iodine. The Cordes bands of the iodine molecules are excited with light energy of a known wavelength (e.g., between 175-210 nanometers) to generate fluorescent emission. At least a portion of the emission's light intensity is collected and used to generate an emission spectrograph. The spectrograph's vibrational energy level peaks are fitted to a vibrational Boltzmann distribution. Specifically, one of the vibrational energy level peaks associated with molecule population in a ground vibrational energy level at a wavelength greater than the known wavelength of the light energy is selected. Next, a plurality of ratios are generated that define a unique linear relationship for a temperature of the seeded environment.

Abstract: A dual discharge tube excimer laser is provided. An oscillator having a first discharge tube generates a laser beam having a cross-sectional shape as initially defined by the first discharge tube. The oscillator selects a bandwidth of the laser beam and maintains the cross-sectional shape of the laser beam within the oscillator and as it exits the oscillator. The laser beam exiting the oscillator is amplified by one pass through the first discharge tube and two passes through a second discharge tube.