Poster Excerpts 2: A Novel Spectrometer for Neutrino Experiments
(Author: Laura Pasqualini, for the NESSiE Collaboration)
The WA104 – NESSiE Collaboration aims to develop a high precision muon spectrometer in the 0.5-5 GeV/c range for applications in future neutrino experiments. Preliminary studies have shown that a tracking system with a spatial resolution of about 1 mm, operating inside a 0.12 T magnetized air volume would allow a charge mis-identification of ~ 1 % at 1 GeV/c, required for an accurate determination of the neutrino beam components.
A R&D program was carried out to prove that an innovative use of planes of triangular scintillator bars (of cm size) equipped with Silicon Photomultipliers (SiPM) in analog mode read out could achieve a spatial resolution of the order of 1 mm.
The X position of a crossing particle is reconstructed from the pulse height in each channel, namely:
where xi is the fiber nominal position and wi is the pulse height in the i-th channel.
Tests triggering on cosmic rays muons were performed requiring at least a signal over threshold in each plane of triangular bars.
This experimental approach will be implemented in a multiplane (meter scale) prototype to be tested with charged beams to set the ultimate achievable spatial accuracy.
Figure: (a) Sketch of the R&D layout. The tracking system is composed by 2 modules of triangular scintillator bars. Each module has 2 detector planes, 4 channels each. (b) Picture (adapted from Ref. ) of scintillator bars with embedded Wavelength Shifter. (c) Residuals between the reconstructed X positions and fitted track projections in each plane of triangular bars. The achieved spatial resolution is better than 2 mm.
 arXiv:1305.5199 [physics.ins-det].