Transmission-mode diamond X-ray position sensitive detector and its applications in synchrotron radiation beamlines

Abstract Background: X-ray position sensitive detector is indispensable for beamlines at synchrotron radiation facilities. Synthetic single-crystal diamond position sensitive detectors have been developed to take advantage of next-generation synchrotron sources, which are trending toward use of high-flux beams and/or beams requiring enhanced stability and precise understanding of beam position and intensity from the front end of the beamline all the way to the sample in recent years. Purpose: It is aimed to provide accurate real-time position and flux for high-flux X-ray beams. Methods: Based on the principle of potentiometers, the transmission-mode diamond X-ray position sensitive detector works as a 'solid' ionization chamber. When the X-ray beam comes into the detector's sensitive region, electronic-holes occur due to the effect of ionization and the charges or the current pulses on the electrodes of the detector are given. According to the collected currents on the electrodes, the location of the incident X-ray can be determined by the ratio between the current difference of electrodes and the total current. Results: A signal/noise ratio of (S/N) > 5× 10³ and a position resolution of σ = (136 ± 11) nm for the synthetic single-crystal diamond position sensitive detector with an active area of 2.5 mm × 2.5 mm, respectively, have been obtained. The measurement precisions for the X-ray beam intensity and position linearity are less than 0.1%. Conclusion: We have demonstrated the feasibility of building a transmission-mode synthetic single-crystal diamond X-ray position sensitive detector, which could measure X-ray beam intensity and position in real time. Its performance was determined on the macromolecular crystallography beamline (BL17U1) at SSRF. Experimental data show that the diamond detector has good linear response and measurement precision of beam intensity within the whole active area. (authors)