title: On the use of CCD area detectors for high-resolution specular X-ray reflectivity.
abstract: 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 (approximately 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 approximately 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 alpha-Al2O3 (012)-water interfaces, with measured reflectivity signals varying by a factor of approximately 10(6) 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.
authors.affiliation: Chemistry Division, Argonne National Laboratory, Argonne, IL 60439, USA. fenter@anl.gov
authors.forename: P
authors.initials: P
authors.lastname: Fenter
authors.forename: J G
authors.initials: JG
authors.lastname: Catalano
authors.forename: C
authors.initials: C
authors.lastname: Park
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D004867:Equipment Design; D007089:Image Enhancement / Q000295:instrumentation*; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013673:Technology Assessment, Biomedical; D014159:Transducers; D014961:X-Ray Diffraction / Q000295:instrumentation* / Q000379:methods