title: The point-spread function of fiber-coupled area detectors.
abstract: The point-spread function (PSF) of a fiber-optic taper-coupled CCD area detector was measured over five decades of intensity using a 20 µm X-ray beam and ~2000-fold averaging. The `tails' of the PSF clearly revealed that it is neither Gaussian nor Lorentzian, but instead resembles the solid angle subtended by a pixel at a point source of light held a small distance (~27 µm) above the pixel plane. This converges to an inverse cube law far from the beam impact point. Further analysis revealed that the tails are dominated by the fiber-optic taper, with negligible contribution from the phosphor, suggesting that the PSF of all fiber-coupled CCD-type detectors is best described as a Moffat function.
authors.affiliation: Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158-2330, USA. jmholton@lbl.gov
authors.forename: James M
authors.initials: JM
authors.lastname: Holton
authors.forename: Chris
authors.initials: C
authors.lastname: Nielsen
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Frankel
mesh_terms: D005336:Fiber Optic Technology; D014965:X-Rays