New X-ray area detectors are available for BESSRC users

Guy Jennings

The MARCCD detector

The MAR345 detector

We have recently purchased two new X-ray area detectors from mar research and they are now available to users. The MARCCD detector is a 2048x2048 pixel CCD detector with a 200mm diameter active area. Readout time is approximately 2 seconds. The MAR345 detector is a 345mm diameter image plate system with a maximum resolution of 3450x3450 pixels. Lower resolutions and/or smaller readout diameters are possible. Readout time is between 30 to 108 seconds, depending on the resolution and image size chosen.

Each detector is complete with a separate Linux data acquisition computer with detector readout and image analysis software. These computers are moved around to whichever beamlines the detectors are used at. Neither detector has an X-ray shutter so it is necessary o synchronize the readout with an external shutter. On most beamlines it is sufficient to use a shutter in one blade of the XIA filter boxes but on the high energy beamlines this does not provide sufficient attenuation and we must use the beamline photon shutter instead. We have a collection of macros and interface programs to allow the readout to be controlled from 'spec'.

The image file format produced by the two detectors is different - the CCD produces approximately fixed-size files in the TIFF file format whereas the image plate scanner uses a specialized compressed file format. Each have approximately 16 bits of intensity resolution. Both computer systems have software installed to perform a variety of image format conversions. At present, it is most convenient to copy the image files over the network to your own computers, but as time and funding permits we will upgrade the computers with recordable DVD drives. It is also possible to copy data files onto an external hard disk or to a laptop computer if you care to bring one over during your experimental run.

For more technical information about these detectors you can visit the mar research website at http://www.marresearch.com/