Effect of Synchrotron Polarization in Grazing Incidence X-ray Fluorescence analysis

Total reflection x-ray fluorescence (TXRF) spectroscopy has seen a remarkable progress over the past years. Numerous applications in basic and applied sciences prove its importance. The large spectral background which is a major detrimental factor in the conventional x-ray fluorescence technique, limits the element detection sensitivities of the technique to ppm range. This spectral background reduces to a great extent in the TXRF technique due to the low extinction depth of the primary incident x-ray beam. In synchrotron radiation (SR) based TXRF measurements the spectral background reduces further because of the polarization of the synchrotron x-ray beam. Here, we discuss in detail the influence of synchrotron polarization on the spectral background in a fluorescence spectrum and its significance towards TXRF detection sensitivities. We provide a detailed theoretical description and show that how anisotropic scattering probability densities of the Compton and Elastic scattered x-rays depend on the scattering angle ({\theta}) and azimuthal angle ({\phi}) in the polarization plane of the SR beam.