OFFSET: Optical Fiber Folded Scintillating Extended Tracker Lo Presti, D.; Aiello, S.; Bonanno, D.L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2014, Volume:
737
Journal Article
Peer reviewed
Open access
The OFFSET collaboration aims at the development of a novel system for tracking charged particles, designed to achieve real-time imaging, large detection areas, and a high spatial resolution ...especially suitable for use in medical diagnostics. This paper presents the first prototype of this tracker, having a 20×20cm2 sensitive area made by two crossed ribbons of 500μm square scintillating fibers. The track position information is extracted in real time using a reduced number of read-out channels to obtain very large detection area at moderate cost and complexity. The performance of the tracker was investigated using β sources, cosmic rays and a 62MeV proton beam.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The performances of the OFFSET3 tracker (Optical Fiber Folded Scintillating Extended Tracker) are presented. It exploits a novel system for particle tracking, designed to achieve real-time particle ...imaging and tracking, large detection areas, and a high spatial resolution especially suitable for applications in medical diagnostics. The tracker is composed by two 288 × 288 mm 2 FOV position detectors stacked by 10 cm, made by 500 micron square scintillating fiber ribbons for both directions. The track position information is extracted in real-time in an innovative way, using a reduced number of readout channels, by means of which it is possible to obtain the large detection area with moderate cost and complexity. The architecture has been patented by the Istituto Nazionale di Fisica Nucleare (INFN). The performances of the tracker were investigated by beta sources, cosmic rays, 60 MeV-250 MeV proton and 400 MeV/A carbon clinical beams.
Gravimetric methods are expected to play a decisive role in geophysical modeling of the regional crustal structure applied to geoneutrino studies. GIGJ (GOCE Inversion for Geoneutrinos at JUNO) is a ...3‐D numerical model constituted by ~46 × 103 voxels of 50 × 50 × 0.1 km, built by inverting GOCE (Gravity field and steady‐state Ocean Circulation Explorer) gravimetric data over the 6° × 4° area centered at the JUNO (Jiangmen Underground Neutrino Observatory) experiment, currently under construction in the Guangdong Province (China). The a priori modeling is based on the adoption of deep seismic sounding profiles, receiver functions, teleseismic P wave velocity models, and Moho depth maps, according to their own accuracy and spatial resolution. The inversion method allowed for integrating GOCE data with the a priori information and some regularization conditions through a Bayesian approach and a stochastic optimization. GIGJ fits the highly accurate and homogeneously distributed GOCE gravity data with a ~1 mGal standard deviation of the residuals, compatible with the observation accuracy. GIGJ provides a site‐specific subdivision of the crustal layers masses, of which uncertainties include estimation errors, associated to the gravimetric solution, and systematic uncertainties, related to the adoption of a fixed sedimentary layer. A consequence of this local rearrangement of the crustal layer thicknesses is a ~21% reduction and a ~24% increase of the middle and lower crust geoneutrino signal, respectively. The geophysical uncertainties of geoneutrino signals at JUNO produced by unitary uranium and thorium abundances distributed in the upper, middle, and lower crust are reduced by 77%, 55%, and 78%, respectively. The numerical model is available at this site (http://www.fe.infn.it/radioactivity/GIGJ).
Key Points
A gravity‐based 3‐D crustal model beneath the Guangdong province (China) was built to predict the geoneutrino signal at the JUNO experiment
The adopted Bayesian method allows for fitting gravimetric observations integrating local prior distribution with regularization conditions
GIGJ fitted GOCE gravity data with a ~1 mGal standard deviation of the residuals, compatible with the observation accuracy
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The current work is a part of the NUMEN project, which aims to deduce the nuclear matrix elements (NME) of neutrinoless double beta decay by measuring the cross sections in heavy-ion induced Double ...Charge Exchange (DCE) reactions. The particle identification for the competing transfer reaction channels has been studied for the 18O + 116Sn system at 270 MeV.
Large-area PhotoMultiplier Tubes (PMT) allow to efficiently instrument Liquid Scintillator (LS) neutrino detectors, where large target masses are pivotal to compensate for neutrinos' extremely ...elusive nature. Depending on the detector light yield, several scintillation photons stemming from the same neutrino interaction are likely to hit a single PMT in a few tens/hundreds of nanoseconds, resulting in several photoelectrons (PEs) to pile-up at the PMT anode. In such scenario, the signal generated by each PE is entangled to the others, and an accurate PMT charge reconstruction becomes challenging. This manuscript describes an experimental method able to address the PMT charge reconstruction in the case of large PE pile-up, providing an unbiased charge estimator at the permille level up to 15 detected PEs. The method is based on a signal filtering technique (Wiener filter) which suppresses the noise due to both PMT and readout electronics, and on a Fourier-based deconvolution able to minimize the influence of signal distortions—such as an overshoot. The analysis of simulated PMT waveforms shows that the slope of a linear regression modeling the relation between reconstructed and true charge values improves from 0.769±0.001 (without deconvolution) to 0.989±0.001 (with deconvolution), where unitary slope implies perfect reconstruction. A C++ implementation of the charge reconstruction algorithm is available online at 1.
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