Diamond photoconductive structures for positioning of X-ray beam

One-dimensional position-sensitive device prototypes were developed for monitoring the position and intensity of a continuous or chopped X-ray beam. The response in terms of linearity and sensitivity were studied on voltage division structures, in the photoconductive charge-generation regime. High-quality polycrystalline diamond samples, mechanically polished for photolithography processing, were used as photoconductor material. Chromium deposits were patterned to realize resistive elements with kΩ resistance values. Developed prototypes were characterized by using a monochromatic 8.06 keV X-ray beam delivered by a collimator 1 mm in diameter. An average non-linearity of 5.5±0.5% on 6 mm long active devices was observed. Sensitivity on the beam intensity variations over one order of magnitude was also evidenced, together with lateral resolutions in the range 0.2-1.2 μV/25 μm.