A CCD Wavefront Sensing System for the ESO Multi-Conjugate Adaptive Optics Demonstrator (MAD)

MAD’s mission is to demonstrate the feasibility of Multi-Conjugate Adaptive Optics (MCAO) as a prerequisite for the 100-m OWL telescope, as well as several 2nd Generation VLT Instruments. It aims at comparing the relative merits of different methods and, therefore, alternatively employs multiple Shack-Hartmann and layer-oriented wavefront sensors requiring 3 and 2 detector units respectively. The 5 detector heads will be identical and equipped with CCD50 devices from Marconi, which have already been successfully tested with the VLT AO instrument NAOS-CONICA. ESO’s standard CCD controller FIERA will be utilized in its new version, upgraded to a PCI bus board.