LASER FREE MEASUREMENTS OF ABSORPTION AND FLUORESCENCE EXCITATION-SPECTRA IN A SUPERSONIC FREE JET

Measurements of the absorption and fluorescence excitation spectra in a supersonic free jet are performed simultaneously with the use of a d c Xe lamp and lock-in detection. With this inexpensive equipment it is possible to measure spectral features from UV to VIS with absorbances as low as 5X10(-6) and with a spectral resolution of 0.9 Angstrom. Ab sorption and fluorescence excitation spectra of 9-cyanoanthracene, whi ch is solid and nonvolatile under ambient conditions, are presented. A chievable signal-to-noise ratios are theoretically calculated and expe rimentally verified. (C) 1996 American Institute of Physics.