A Deep, Wide-Field Weak Lensing Survey with MEGACAM

This brief document is a response to the call for ideas for CFHT imaging surveys with MEGACAM. We have been carrying out wide eld, deep imaging at the CFHT for several years now, with the primary science goal of using weak lensing of faint galaxies to probe the dark matter distribution on a range of scales from galaxy halos through galaxy cluster scales to supercluster scales. Thus far we have accumulated data with the UH8K on six 0Æ:5 0Æ:5 elds with 1 hour integrations in I and V passbands. We are now embarking on an extension of the survey using the 0Æ:75 0Æ:5 CFH12K camera. We eagerly anticipate the advent of the MEGACAM camera for its extended image size, spectral coverage and improved image quality. In what follows, we describe the rationale behind our choice of survey eld layout in x2; we describe the choice of lters and integration times in x3. We then outline the parameters of an advanced weak lensing survey using MEGACAM in x4.