SYSTEMATIC-ERRORS IN POLARIZATION-DEPENDENT ELECTRON YIELD EXPERIMENTS

We critically review experiments that reported that the pulse yield of CsI depends on the state of polarization of the incident X-rays. We s how that such experiments, and possibly other polarization dependent e xperiments, are susceptible to serious systematic errors, particularly at small grazing incidence angles. We present a model that accounts f or the different systematic errors, and measurements that demonstrate the validity of the model. We analyze the particular experimental para meters of some of the pulse yield experiments and conclude that their results were affected by the systematic errors and hence have to be re tracted. According to a set of measurements designed to avoid these sy stematic errors the pulse yield of CsI does not depend on the polariza tion state of the incident X-rays.