AN AREA X-RAY-DETECTOR SYSTEM BASED ON A COMMERCIALLY AVAILABLE CCD-UNIT

A two-dimensional x-ray detector has been developed by combining a fiber-optic face plate (FOFP) which was deposited with a thin layer of phosphor (Y2O2S:Tb), a high-quality camera lens, and a slow-scan fiber-optics (FO) bonded charge-coupled device (CCD) camera system. The detector showed good linearity of response to the incident x-ray intensity and good spatial linearity. It had an effective area on the phosphor screen of 31.5 mm× 47.2 mm. Low CCD dark count allowed up to about 30 min of continuous measurement. No radiation damage was detected, even for measurements of the synchrotron x-ray main beam. However, the detector quantum efficiency was low (∼25%), and the bonding between the FO and the CCD was very fragile, so that the chicken wire pattern produced by the bonded FO introduced a 5% error in detector sensitivity which was difficult to correct. However, such a detector with a non-FO-bonded CCD camera system instead of the FO-bonded CCD system should be ideal for extended x-ray absorption of fine structure (EXAFS) experiments.