Use of Hadamard-based movable masks is demonstrated to be an effective method for obtaining spatially resolved information from x-ray photoelectron spectroscopy (XPS or ESCA). The concept of such imaging in electron spectroscopy is discussed in conjunction with the results obtained from a relatively simple mask system which was attached to a modified AEI ES200 photoelectron spectrometer. Resolution on the order of 1 mm2 was obtained with this configuration. The ultimate spatial resolution, on the order of microns, depends on engineering limitations concerned primarily with mask design and fabrication. The advantage of such a system stems from its inherent multiplexing nature, the requirements for only a single-channel detector, and the associated possibility of retro-fitting currently existing instrumentation.
Douglas P. Hoffmann, Andrew Proctor, and David M. Hercules, "Spatially Resolved ESCA Using Hadamard Masks," Appl. Spectrosc. 43, 899-908 (1989)