Abstract
Muon Radiography allows to map the density of a volcanic cone. It is based on the measurement of the attenuation of the flux of muons present in the cosmic radiation on the ground. The MU-RAY project has developed an innovative detector designed for the muon radiography. The main features are the low electric power consumption, robustness and transportability, good spatial resolution and muon time of flight measurement. A 1 m2 detector prototype has been constructed. and collected data at Mt. Vesuvius for approximately 1 month in spring 2013. A second campaign of measurement has been performed at the Puy de Dôme, France, in the last four months of 2013. In this article the principles of muon radiography, the MU-RAY detector and the first results from the collected data will be described.