Thermal Wave Imaging nd Characterization of Solids

Accomplishments are reported of a program of research to develop several thermal wave techniques and to explore applications of those techniques to the imaging of sub-surface features and the characterization of a variety of materials. Both experimental and theoretical studies were carried out, and the experiments included both cw and pulsed thermal wave excitation. The mirage effect optical probe beam technique was used to determine thermal diffusivities in a variety of materials including diamond and polymers. The results of our measurements on single crystal diamond showed a nearly 50 increase in thermal diffusivity at room temperature on IR thermal wave imaging for nondestructive evaluation NDE included synchronous imaging in the time domain, a technique for thermal wave tomography was developed, and the inverse scattering problem was solved and an algorithm developed to implement the solution on digitally acquired images. A U.S. Patent was issued to Wayne State University on the lock-in video technique. Instrumental development was carried out culminating in a Beta-site development at an aerospace company and negotiations with several companies towards commercialization of the instrumentation for technology transfer.