research papers
The use and application of charge coupled device (CCD) area detectors for high-resolution specular X-ray reflectivity is discussed. Direct comparison of high-resolution specular X-ray reflectivity data measured with CCD area detectors and traditional X-ray scintillator (`point') detectors demonstrates that the use of CCD detectors leads to a substantial (∼30-fold) reduction in data acquisition rates because of the elimination of the need to scan the sample to distinguish signal from background. The angular resolution with a CCD detector is also improved by a factor of ∼3. The ability to probe the large dynamic range inherent to high-resolution X-ray reflectivity data in the specular reflection geometry was demonstrated with measurements of the orthoclase (001)– and α-Al2O3 (012)–water interfaces, with measured reflectivity signals varying by a factor of ∼106 without the use of any beam attenuators. Statistical errors in the reflectivity signal are also derived and directly compared with the repeatability of the measurements.