MIT/Lincoln Labs CCID20 W72C2 CCD Test Results

This is a high-resistivity CCD and is 40 microns thick. A report is available. Highlights from the report include:

Bright column. A very bright column limits our ability to make useful measuremnts of the entire array. Counting from the A-amplifier the column number of the bright column is about 1256 and is on theB-side of the CCD. Therefore all measurements are made using the A-amplifier side of the device. Also, because the bright column limits the usefulness of this device we have not carried out a complete series of tests.
Quantum Efficiency. The QE curve shows excellent red response.
QE uniformity. The brick wall pattern is low and virtually non-existant in the far red.

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. There are also additional postscript files showing the brick-wall pattern as well as some raw data files. Check the INDEX file for a description of what the other files contain. Here are a few figures to illustrate device highlights:

QE curve

The QE of this device is compared to W6C2, a standard epi CCD.

Fringing

Images showing fringing.

This plot shows QE measurements made on W72C2 and W6C2 at a device temperature of -80°C. The improved QE of the thick, high-resistivity CCD is clear.

W72C2 shows higher QE in the red than does W6C2.

This plot shows fringing at three wavelengths. A neon emission lamp is used along with narrow band filters to isolate individual lines.