The OPERA experiment: automated development of nuclear emulsions, installation and results of the Padova microscope

The OPERA experiment aim is to verify the neutrino oscillation, directly measuring the appearance of tau neutrinos from an initially almost pure muon neutrinos beam produced at CERN. Its target will be made of about 160000 bricks of nuclear emulsion films sandwiched with 1-mm-thick lead plates. The total mass of the experiment will be of about 1.3 kton. The first physics run has been available in October 2007, when 38 muon neutrino events have been recorded. During its expected 5-year lifetime, OPERA will extract for analysis about 15% of the total amount of emulsions. These films need to be developed at LNGS laboratories at the rate of 20-30 bricks per day, 200 days per year and then scanned by microscope stations in the OPERA laboratories worldwide. The impressive amount of emulsions to be processed and analyzed require automated large-scale chemical development and computer-driven optical scanning. This Ph.D. thesis reports my job on the design and production of the control software for the automatic emulsion development system and on the automatic scanning station installed at LNL laboratories. Concerning the former project, I have studied the best software structure to provide flexibility and ease of maintenance for the code. The realized program provides optimal scheduling of any number of bricks simultaneously developed on the automated lines. The latter project involved the full installation, setting-up and testing of the scanning system. The goal, that has been successfully achieved, was the full reconstruction of a neutrino interaction inside one of the 38 OPERA brick extracted during the first physics run.