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

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 -1 s -1 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.