N2CARS thermometry within the outer jacket of a metal halide lamp

We applied high-resolution coherent anti-Stokes Raman spectroscopy (CARS) to measure the gas temperature at a number of points within the nitrogen-filled outer jacket of a 360 W metal halide lamp. A comparison between the measured rotationally resolved N-2 CARS spectra with spectral simulations collected between 500 and 1000 K allowed the temperature at each point in the lamp to be determined. In addition to demonstrating the diagnostic power of the CARS technique in a high-intensity discharge lamp, a comparison of the measured temperatures to calculated axial and radial temperature profiles was achieved. Good agreement between the theoretical and experimental temperature profiles was attained.