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Characterization of image plates for neutron diffraction
Author(s) -
Wilkinson Clive,
Lehmann Mogens S.,
Meilleur Flora,
Blakeley Matthew P.,
Myles Dean A. A.,
Vogelmeier Stefan,
Thoms Michael,
Walsh Michael,
McIntyre Garry J.
Publication year - 2009
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889809024856
Subject(s) - detective quantum efficiency , optics , physics , detector , diffraction , neutron , point spread function , neutron detection , image (mathematics) , image quality , computer science , nuclear physics , artificial intelligence
A method to measure the overall gain and point‐spread function of an image‐plate detector system (converter, phosphor, readout electronics) online from single‐crystal diffraction patterns is derived. Only with a knowledge of these quantities can one estimate without bias the true standard deviations of the observed integrated intensities of Bragg reflections measured with such a detector. The gain corrected for the point‐spread function should ideally be approximately 1.0 to avoid loss of data or precision due to the upper and lower limits of digitization of the diffraction patterns. The gain and the point‐spread function are derived for several configurations of the three neutron Laue image‐plate diffractometers, LADI, VIVALDI and LADI‐III, at the Institut Laue–Langevin. The detective quantum efficiencies (DQE) of these instruments have been measured to be 0.16 (1), 0.57 (2) and 0.46 (3), respectively. It has also been found that the DQE is effectively constant for different times of exposure, despite the fading of the photostimulated luminescent signal during that time. While the results described in this paper concern neutron detection by image plates, the method is equally valid for other integrating detectors and radiations, e.g. CCD detectors and X‐rays.