10 April 1995 Gold detector: modular CCD area detector for macromolecular crystallography
Author Affiliations +
Abstract
We have designed, fabricated, and tested a modular CCD area detector system for macromolecular crystallography at synchrotron x-ray sources, code-named the `gold' detector system. The sensitive area of the detector is 150 mm X 150 mm, with 3,072 X 3,072 pixel sampling, resulting in roughly a 50 micrometers pixel raster. The x-ray image formed on the face of the detector is converted to visible light by a thin phosphor layer. This image is transferred optically to nine CCD sensors by nine square fiberoptic tapers (one for each CCD), arranged in a 3 X 3 array. Each taper demagnifies the image by a factor of approximately 2. Each CCD has a 1,024 X 1,024 pixel raster and is read out through two independent data channels. After each x-ray exposure period the x-ray shutter is closed and the electronic image is digitized (16-bit) and read out in 1.8s. Alteratively, the image may be binned 2 X 2 during readout, resulting in a 1,536 X 1,536 raster of 100 micrometers pixels; this image can be read out in 0.4s. The CCD sensors are operated at -40 degree(s)C to reduce electronic noise. The detector is operated under full computer control: all operational parameters (readout rates, CCD temperature, etc.) can be adjusted from the console. The image data (18 MByte/image) are transferred via a fast VME system to a control processor and ultimately to disk storage. During April 1994 we carried out a complete set of measurements at the Stanford Synchrotron Radiation Laboratory (SSRL) for a full characterization of the gold detector. Characterization includes quantitative evaluation of the instrument's conversion gain (signal level/x-ray photon); detective quantum efficiency (DQE); point-spread function; sensitivity as a function of x-ray energy; geometrical distortion of images; spatial uniformity; read noise; and dark image and dark image noise. Characterization parameters derived from these measurements show that this detector will be extraordinarily valuable for macromolecular crystallography.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Istvan Naday, Stephan W. Ross, Miklos Kanyo, Mary L. Westbrook, Edwin M. Westbrook, Walter Charles Phillips, Martin J. Stanton, Daniel M. O'Mara, "Gold detector: modular CCD area detector for macromolecular crystallography", Proc. SPIE 2415, Charge-Coupled Devices and Solid State Optical Sensors V, (10 April 1995); doi: 10.1117/12.206519; https://doi.org/10.1117/12.206519
PROCEEDINGS
14 PAGES


SHARE
Back to Top