RESOLUTION ENHANCEMENT OF X-RAY PHOTOELECTRON-SPECTRA BY MAXIMUM-ENTROPY DECONVOLUTION

The maximum entropy method (MEM) is applied to the deconvolution of x- ray photoelectron spectra. This method provides the least-biased estim ate of the unbroadened spectrum by using the Shannon information conte nt as the regularizing functional. The large-scale, non-linear optimiz ation problem is solved using a robust variable metric sequential-quad ratic programming (SQP) algorithm implemented on a personal computer ( PC). The program is tested on simulated spectra and then shown to prov ide reliable resolution enhancement of measured spectra by unfolding a measured instrumental resolution function. Typical resolution enhance ments of 50% are achievable in <15 min of computer time. (C) 1998 John Wiley & Sons, Ltd.