Characterization of the CSST Survey Camera CCDs: I. basic electro-optical performance

Abstract

The Chinese Space-station Survey Telescope (CSST) is a flagship mission designed to carry out a large-area high-resolution multiband imaging and slitless spectroscopic survey over a decade. The survey's science drivers, ranging from precision cosmology to stellar astrophysics, impose stringent requirements on the performance of its focal plane detectors. This paper is the first in a series that present ground-based characterization of the 31 flight-model charge-coupled devices (CCDs) of the CSST Survey Camera. Measurements of basic electro-optical performance are reported here. Key results include: full-well capacity>80 ke (limited by the test electronics), non-linearity<1.4% in the range of 7-70 ke, median readout noise 3.6 e, dark current<0.02 e/pix/s at the operating temperature of -85 degree celsius, high quantum efficiency across the survey's spectral range (255-1000 nm), typical pixel response non-uniformity<1%, and charge transfer efficiency>99.9994% at the flat-field level of 10 ke. All 31 CCDs meet or exceed the Survey Camera's specifications. These measurements establish a performance baseline and provide inputs for CSST image simulation and data processing pipelines