Borexino: A new calorimeter for low energy solar neutrinos

Borexino is a new real-time detector for low energy solar neutrinos presently in construction at the Gran Sasso Laboratories, in Italy. The main goal of the Borexino experiment is the detection of the 0.861 MeV Be-7 neutrino line, one of the missing links on the solar neutrino problem. The use of liquid scintillator as the active material allows the achievement of a low energy theshold and unprecedented low background levels. This paper will review the goals and design of the Borexino experiment, discussing both its relevance to the general solar neutrino physics scenario and the most crucial experimental aspects, including the results of the prototype experiment, Counting Test Facility (CTF).