Track reconstruction in the emulsion-lead target of the OPERA experiment using the ESS microscope

Abstract

The OPERA experiment, designed to conclusively prove the existence of $\hat{\mathrm{I}}{½}_{\hat{\mathrm{I}}}¼\to \hat{\mathrm{I}}{½}_{\ddot{\mathrm{I}}}„$ oscillations in the atmospheric sector, makes use of a massive lead-nuclear emulsion target to observe the appearance of $\hat{\mathrm{I}}{½}_{\ddot{\mathrm{I}}}„$'s in the CNGS $\hat{\mathrm{I}}{½}_{\hat{\mathrm{I}}}¼$ beam. The location and analysis of the neutrino interactions in quasi real-time required the development of fast computer-controlled microscopes able to reconstruct particle tracks with sub-micron precision and high efficiency at a speed of 20 cm^2 / h. This paper describes the performance in particle track reconstruction of the European Scanning System, a novel automatic microscope for the measurement of emulsion films developed for OPERA.

13 pages, 10 figures