Design of the electronical system for a 2x2 mosaic CCD camera

The Wide Field Survey Telescope (WFST) is a proposed 2.5m-aperture wide field survey telescope intended for dedicated wide field sciences in China. The focal-plane instrument is a mosaic CCD camera comprising 9 pieces of 9K x 9K pixels CCD chips. In order to verify the WFST mosaic solution, we designed a 2x2 mosaic camera test system using CCD303-88. The mechanical design of vacuum chamber, cryogenic refrigeration of CCD, mosaic CCD technique and multi CCD control electronic have been implemented on this system. We design a CCD controller capable of controlling two pieces of CCDs and a power supply module for the controller. The cryogenic refrigeration control is implemented with a refrigerator and temperature control electronics.