MIT/Lincoln Labs CCID20 W97C2 CCD Test Results

This is a high-resistivity phase 2 MIT/Lincoln Labs 2Kx4K CCD. It has improved brick wall. Since it is a high resisitivity device the added thickness gives it improved red QE and lower fringing. For some reason this device has a high spatial-frequency QE variation. A summary report is available. Noteworthy points about this CCD include:

Original postscript files are available from our anonymous ftp server and these provide better resolution and clarity than is usually possible on a web page. Here are a few figures to illustrate device highlights:

High frequency variations
The brick wall pattern on this device is nearly obscured by the higher amplitude high frequency variations.
Surface plot
The surface flatness is not quite as good as other phase 2 devices, but it is still good enough for most purposes.

Here we show two row plots. The first is a section of a row in a 4000A flat field and the second is the same section of a row in a 7000A flat field. The two plots show a similar fixed pattern. The RMS variation in the 4000A image is 3.7% and it is 3.1% in the 7000A image. Because the pattern is not identical in the two images, dividing one image by the other does not remove the fixed pattern completely. The characteristic size of these variations appears to be about 4 or 5 pixels and no regular structure is visible (see the image files in the ftp directory).

The surface profile was measured using the UCO/Lick surface flatness machine. Peak-to-peak the surface varies by about 20 micometers.

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