Liquid rare gas detectors: recent developments and applications

In the past few years, the liquid rare gas detectors (LRGD) have made a considerable progress and found application in various fields of research, such as high energy experiments, astrophysics, search of rare processes and medical imaging. In this paper, the two best established technologies based on liquid rare gases - electromagnetic calorimeters and time projection chambers - are briefly reviewed, together with their applications. The bulk of the paper is focused on the challenging development of LRGD for the search of rare processes in low background experiments and on the promising application of LRGD to medical imaging. The present status of some of the more significant developments under way is presented.