Summary

Using a synchrotron light source and a translation stage, we have mapped a suite of flight candidate UV/optical blocking filters for ACIS, in five energies and with high spatial resolution. The maps show the filters to be quite uniform, with deviations no larger than about 2%.

Based on these data and Luxel's specifications, the filters were ranked for their suitability for flight. The best imaging array filter (009) and spectroscopy array filter (003) are now installed in the ACIS flight focal plane. The other filters are maintained in a clean environment and will be reserved as backups for the flight filters and for future tests.