Readout Electronics for Hyper Suprime-Cam

Abstract Hyper Suprime-Cam(HSC)isa1GigapixelCCD camerafora wide-fieldgalaxy surveyatthe Subaru8-mTelescope. It will be mounted on the prime focus of the SubaruTelescope and is scheduled to receive its first light in 2012. The primary science is to conduct a weak lensing survey over ∼ 2,000 square degrees. The HSC has a 1.5-degree-diameter fieldofview, 7timeslarger than thatofits predecessor Suprime-Cam.It consistsofalarge corrector lens systemand afocalplane equippedwith116piecesof2kx4kfully depletedCCDs. Combinedwiththesuperbimagequalityand large aperture of the Subaru telescope, the surveyusing HSC can cover a cosmological volume and reach the limiting magnitude of at least one magnitudefainter than the other surveys conducted using 4-m class telescopes. The readout electronics of the HSC consist of two parts: one is the analog front-end electronics (FEE) and the other is the digital back-end electronics (BEE). The FEE is placed in a vacuum dewar together with the CCDs, and processes the analog CCD signal into 16-bit digital data. The BEE is small and light enough to be integrated into the camera unit, and employs three linksofGigabit Ethernetto readouta 2.3-GByte singleexposure within10 secondsatfast readout operation. The readout noise from the electronics is smaller than that from CCDs.