Channelplate illumination correction for secondary ion mass spectroscopy images by solving apparatus elasticity equations

The SIMS channelplate used for recording image signals is characterized by local sensitivity differences caused by increasing aging of the central cha nnelplate regions, which are subject to much more intense ion bombardment t han the outer regions. These sensitivity differences lead to inhomogenous i llumination of the sample, i.e., to images with disturbed intensity distrib utions. We present here a novel method to correct these illumination discre pancies by using the intensity changes due to sample position shifts to fin d the interfering background function that can be used to correct the origi nal image. The proposed method has low presuppositions about the regarded i mages, and is stable with regard to noise and easy to apply. It is suitable not only for correction of channelplate local sensitivity differences but for all sorts of microscopic images that suffer from illumination inhomogen eity.