Design and status of the optical corrector for the DES survey instrument

The DECam instrument, for the 4m Blanco telescope at CTIO, is a 5 lens element wide field camera giving a 2.2 degree diameter field of view. The lenses are large, with the biggest being 980mm in diameter, and this poses challenges in mounting and alignment. This paper reports the status of the production of the optics for the DECam wide field imager Also presented are the design and finite element modelling of the cell design for the 5 lenses of the imager along with the proposed alignment process.