A combined HST/CFH12k/XMM survey of X-ray luminous clusters of galaxies at z~0.2

We describe a project to study a sample of X-ray luminous clusters of galaxies at redshift z~0.2 at several scales (with HST/WFPC2 and CFHT/CFH12k) and wavebands (optical and X-ray). The main aims of the project are (i) to determine the mass profiles of the clusters on scales ranging from ~10 kpc/h to >1.5 Mpc/h using weak and strong lensing, thereby testing theoretical predictions of a ``universal mass profile'', and (ii) to calibrate the M_tot - T_X relation in view of future application in the study of the evolution of the cluster mass function at higher redshift.