he new astronomical CCD is truly a spin-off of our high -energy physics detector work," says the Engineering Division's Steve Holland, " and had its origin in the R&D effort for the Superconducting Supercollider." Most CCDs are semi-conductor devices that convert patterns of light intropatterns of electric charge, which can be recorded and computer-processed to form images. In particle-accelerator detectors, however, CCDs are used to pinpoint hits by energetic particles. In contrast to astronomical CCDs, most of them thinner than a human hair, a typical particle detector is a slab of silicon 300 micrometers thick, about the thickness of a postcard.