Emulsion sheet doublets as interface trackers for the OPERA experiment

Abstract

New methods for efficient and unambiguous interconnection between electronic counters and target units based on nuclear photographic emulsion films have been developed. The application to the OPERA experiment, that aims at detecting oscillations between mu neutrino and tau neutrino in the CNGS neutrino beam, is reported in this paper. In order to reduce background due to latent tracks collected before installation in the detector, on-site large-scale treatments of the emulsions ("refreshing") have been applied. Changeable Sheet (CSd) packages, each made of a doublet of emulsion films, have been designed, assembled and coupled to the OPERA target units ("ECC bricks"). A device has been built to print X-ray spots for accurate interconnection both within the CSd and between the CSd and the related ECC brick. Sample emulsion films have been extensively scanned with state-of-the-art automated optical microscopes. Efficient track-matching and powerful background rejection have been achieved in tests with electronically tagged penetrating muons. Further improvement of in-doublet film alignment was obtained by matching the pattern of low-energy electron tracks. The commissioning of the overall OPERA alignment procedure is in progress.

19 pages, 19 figures

References in corpus (7)

• A Measurement of Atmospheric Neutrino Oscillation Parameters by Super-Kamiokande I
• Measurement of Neutrino Oscillation by the K2K Experiment
• Observation of muon neutrino disappearance with the MINOS detectors and the NuMI neutrino beam
• Observation of Tau Neutrino Interactions
• Hardware performance of a scanning system for high speed analysis of nuclear emulsions
• First events from the CNGS neutrino beam detected in the OPERA experiment
• Track reconstruction in the emulsion-lead target of the OPERA experiment using the ESS microscope

Cited by in corpus (12)

• Discovery of tau neutrino appearance in the CNGS neutrino beam with the OPERA experiment
• Final results of the OPERA experiment on ${\nu }_{\tau }$ appearance in the CNGS beam
• The detection of neutrino interactions in the emulsion/lead target of the OPERA experiment
• Study of neutrino interactions with the electronic detectors of the OPERA experiment
• Study of the effects induced by lead on the emulsion films of the OPERA experiment
• Search for ${\nu }_{\mu }\to {\nu }_e$ oscillations with the OPERA experiment in the CNGS beam
• Learning from tau appearance
• Nuclear emulsions in the OPERA experiment
• First observation of a tau neutrino charged current interaction with charm production in the Opera experiment
• Segmentation of EM showers for neutrino experiments with deep graph neural networks
• Study of Neutrino Oscillations in the OPERA Experiment
• OPERA: waiting for the tau