Large magnetic liquid mirrors

Abstract

We present a new class of large liquid mirrors that use a ferrofluid covered by a reflecting layer of nanoparticles. The surface of the mirror is shaped by several concentric loops of current carrying coils. We first validate our theoretical models by comparing the theoretical predictions to interferometric measurements of a small prototype, finding agreement between data and theory. We then compute with Monte Carlo simulations models for f/2 mirrors having diameters varying between 15 and 44 m. Although much work remains to be done before a functional large mirror is actually built, our first exploration of the concept indicates that it is technologically feasible, thus warranting further work. © ESO 2006.