THE DARK ENERGY CAMERA

The Dark Energy Camera is a new imager with a 2. 2 diameter field of view mounted at the prime focus of the Victor M. Blanco 4m telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaborationand meets or exceeds the stringent requirements designed for the widefield and supernova surveys for which the collaboration uses it. The camera consists of a five-element optical corrector, seven filters, a shutter with a 60 cm aperture, and a charge-coupled device (CCD) focal plane of 250 m thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 megapixel focal plane comprises 62 2k 4k CCDs for imaging and 12 2k 2k CCDs for guiding and focus. The CCDs have 15 m 15 m pixels with a plate scale of 0 263 pixel -1 . A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 s with 6-9 electronreadout noise. This paper provides a technical description of the cameras engineering, construction, installation, and current status.