Effect of anomalous scattering and K-fluroscence reabsorption on the performance of selenium

Selenium (Se) has been successfully employed as a photoconductor to convert incident X-rays to electronic charges in direct conversion flat panel detectors for digital imaging systems. We have studied the effect of K-fluorescence reabsorption coupled with anomalous scattering on the performance of Se in protein crystallography detectors. Anomalous scattering is used as a method of phase calculation in crystallography. For occurrence of anomalous scattering, incident X-ray energy is made equal to the K-edge energy of Se. Our study indicates that significant K--fluorescence escape and reabsorption occurs at K-edge energy which degrades spatial resolution, sensitivity, and signal-to-noise ratio of the detector.