M. Ieva

Hardware performance of a scanning system for high speed analysis of nuclear emulsions

The use of nuclear emulsions in very large physics experiments is now possible thanks to the recent improvements in the industrial production of emulsions and to the development of fast automated microscopes. In this paper the hardware performances of the European Scanning System (ESS) are described. The ESS is a very fast automatic system developed for the mass scanning of the emulsions of the OPERA experiment, which requires microscopes with scanning speeds of � 20 cm 2 =h in an emulsion volume of 44mm thickness.

Momentum measurement by the angular method in the Emulsion Cloud Chamber

We present the first automated momentum measurement in an Emulsion Cloud Chamber, consisting of multiple sandwiches of lead plates and nuclear emulsion sheets. The measurement is based on the detection of the multiple Coulombscattering analysed by the so-called angular method. A 3 X0 chamber was exposed to 2, 3 and 4 GeV=c p � : A pion momentum resolution of 36% at 4 GeV=c; 35% at 3 GeV=c and 28% for 2 GeV=c was achieved.

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

The OPERA experiment, designed to conclusively prove the existence of ????? oscillations in the atmospheric sector, makes use of a massive lead-nuclear emulsion target to observe the appearance of ??s in the CNGS ?? 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 cm2/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.

Electron/pion separation with an emulsion cloud chamber by using a neural network.

We have studied the performance of a new algorithm for electron/pion separation in an Emulsion Cloud Chamber (ECC) made of lead and nuclear emulsion films. The software for separation consists of two parts: a shower reconstruction algorithm and a Neural Network that assigns to each reconstructed shower the probability to be an electron or a pion. The performance has been studied for the ECC of the OPERA experiment [1]. The e/π separation algorithm has been optimized by using a detailed Monte Carlo simulation of the ECC and tested on real data taken at CERN (pion beams) and at DESY (electron beams). The algorithm allows to achieve a 90% electron identification efficiency with a pion misidentification smaller than 1% for energies higher than 2 GeV.

Measurement of low-energy neutrino cross-sections with the PEANUT experiment

The PEANUT experiment was designed to study the NuMi neutrino beam at Fermilab. The detector uses a hybrid technique, being made of nuclear emulsions and scintillator trackers. Emulsion films act as a micrometric tracking device and are interleaved with lead plates used as passive material. The detector is designed to precisely reconstruct the topology of neutrino interactions and hence to measure the different contributions to the cross section. We present here the full reconstruction and analysis of 147 neutrino interactions and the measurement of the quasi-elastic, resonance and deep-inelastic contributions to the total charged current cross section at the energies of the NuMi neutrino beam. This technique could be applied for beam monitoring in future neutrino facilities, and this paper shows its proof-of-principle.