ABSTRACT 9500525 Danchi, William Townes, Charles $1.7M is being provided to expand the University of California, Berkeley imaging interferometer. This pioneering instrument is expanding the technique of spatial interferometry into the 10 micron atmospheric window. The improved instrument will be used in the study of circumstellar dust shells and protoplanetary disks. It will also further our understanding of heterodyne detection at these wavelengths and of the structure of turbulence in the Earth's atmosphere.