A. Mengucci | Searcharxiv

arXiv2019

Streamer studies in Resistive Plate Chambers

The present paper is meant as an update of the presentation given in a previous Resistive Plate Chamber (RPC) workshop, aimed at finding an eco-friendly gas mixture for streamer operation of RPCs. Indeed the streamer working regime is still suitable for building large RPC systems dedicated to low rate applications, such as cosmic ray and neutrino physics. In addition to other studies about gas mixtures for streamer mode operation, in this paper the replacement of R134a with CF4, a gas widely used in other gaseous detectors, has been investigated. The effect of the gas gap thickness on the discharge quenching has also been studied; this is an important check because thin gas gaps of 1 mm, one half of the typical used value, have been introduced for high rate applications. Finally preliminar results about the streamer formation timing are also reported.

physics.ins-det↗

arXiv2019

Distillation and stripping pilot plants for the JUNO neutrino detector: design, operations and reliability

This paper describes the design, construction principles and operations of the distillation and stripping pilot plants tested at the Daya Bay Neutrino Laboratory, with the perspective to adapt this processes, system cleanliness and leak-tightness to the final full scale plants that will be used for the purification of the liquid scintillator used in the JUNO neutrino detector. The main goal of these plants is to remove radio impurities from the liquid scintillator while increasing its optical attenuation length. Purification of liquid scintillator will be performed with a system combining alumina oxide, distillation, water extraction and steam (or N2 gas) stripping. Such a combined system will aim at obtaining a total attenuation length greater than 20 m at 430 nm, and a bulk radiopurity for 238U and 232Th in the 10-15 to 10-17 g/g range. The pilot plants commissioning and operation have also provided valuable information on the degree of reliability of their main components, which will be particularly useful for the design of the final full scale purification equipment for the JUNO liquid scintillator. This paper describe two of the five pilot plants since the Alumina Column, Fluor mixing and the Water Extraction plants are in charge of the Chinese part of the collaboration.

physics.ins-det↗

arXiv2017

Gas gap studies about streamer operated RPCs

The requirement of high rate capability for operation at LHC, led 20 years ago to the achievement of Resistive Plate Chambers operated in avalanche mode, thanks to the introduction of new gas mixtures and to the development of the Front-End electronics. The need for a further increase of the rate capability, in view of the upgrades of LHC, is imposing new detector geometries with thinner gas gaps and electrodes. Streamer operation of RPCs may still be suitable for low rate experiments, and therefore in this paper a comparison between two different detector geometries, the old standard and the newly proposed one, is performed in streamer mode.

physics.ins-det↗

arXiv2014

The NESSiE way to searches for sterile neutrinos at FNAL

Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle $θ_{13}$ in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small $L/E$, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. Its recent proposal refers to the use of magnetic spectrometers at two different sites, Near and Far ones. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the undergoing project of a multi-site Liquid-Argon detectors at FNAL. The experiment to be possibly setup at Booster will allow to definitively clarify the current $ν_μ$ disappearance tension with $ν_{e}$ appearance and disappearance at the eV mass scale.

hep-ph↗

arXiv2014

Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster

Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle $θ_{13}$ in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small $L/E$, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. This proposal refers to the use of magnetic spectrometers at two different sites, Near and Far. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the CERN project for a new more performant neutrino beam, which will nicely extend the physics results achievable at the Booster. The possible FNAL experiment will allow to clarify the current $ν_μ$ disappearance tension with $ν_e$ appearance and disappearance at the eV mass scale. Instead, a new CERN neutrino beam would allow a further span in the parameter space together with a refined control of systematics and, more relevant, the measurement of the antineutrino sector, by upgrading the spectrometer with detectors currently under R&D study.

hep-ph↗

arXiv2013

The NESSiE Concept for Sterile Neutrinos

Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the third mixing angle theta13 in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, several puzzling measurements exist, which deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake a definitive experiment to clarify the muon disappearance measurements at small L/E, which will be able to put severe constraints to any model with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. Within the context of the current CERN project, aimed to revitalize the neutrino field in Europe, we will illustrate the achievements that can be obtained by a double muon-spectrometer system, with emphasis on the search for sterile neutrinos.

hep-ph↗