INFRARED TOMOGRAPHIC INVERSION FOR COMBUSTION AND INCINERATION

We have developed a complete infrared absorption and tomographic inver sion system. The source, a computer-controlled KCl:Li color center las er, is tunable over the 2.45-2.82 mu m range, allowing spectral access to many combustion and incineration products. A fast wavelength-locki ng algorithm, in conjunction with the laser linewidth of similar to 0. 1 cm(-1), ensures line-center measurements for determination of temper ature and concentration. The newly developed tomographic inversion met hod takes maximum advantage of a priori information, and can require o nly a small number of well-configured line-of-sight measurements to pr oduce accurate reconstructions. Numerical experiments using simulated absorption data to reconstruct both temperature and concentration dist ributions have been performed. As few as 20 line-of-sight measurements are required to produce high-fidelity reconstructions in these numeri cal experiments.