arXiv subjects

Valerio D'Andrea

Publications and source records attributed to Valerio D'Andrea.

3 recordsLinked to original sources

arXiv2026

A compact Optical Liquid Argon Facility at Roma Tre

In this paper we present a compact test facility for the measurement of optical properties of liquid argon as scintillator. The setup is under preparation at Roma Tre and it has a volume of 40 L liquid argon, which is liquefied from argon gas with a purity of $\ge 99.9999\%$ vol. To readout the scintillation photons from liquid argon with the highest intensity near 127 nm, we use the vacuum ultraviolet silicon photomultipliers from Hamamatsu. By submerging the photon detectors directly inside the liquid argon, we can eliminate the systematics from the wavelength shifter and light guides which have been commonly used to detect the scintillation photons of liquid argon.

physics.ins-det↗

arXiv2019

Modeling of GERDA Phase II data

The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double-beta ($0νββ$) decay of $^{76}$Ge. The technological challenge of GERDA is to operate in a "background-free" regime in the region of interest (ROI) after analysis cuts for the full 100$\,$kg$\cdot$yr target exposure of the experiment. A careful modeling and decomposition of the full-range energy spectrum is essential to predict the shape and composition of events in the ROI around $Q_{ββ}$ for the $0νββ$ search, to extract a precise measurement of the half-life of the double-beta decay mode with neutrinos ($2νββ$) and in order to identify the location of residual impurities. The latter will permit future experiments to build strategies in order to further lower the background and achieve even better sensitivities. In this article the background decomposition prior to analysis cuts is presented for GERDA Phase II. The background model fit yields a flat spectrum in the ROI with a background index (BI) of $16.04^{+0.78}_{-0.85} \cdot 10^{-3}\,$cts/(kg$\cdot$keV$\cdot$yr) for the enriched BEGe data set and $14.68^{+0.47}_{-0.52} \cdot 10^{-3}\,$cts/(kg$\cdot$keV$\cdot$yr) for the enriched coaxial data set. These values are similar to the one of Gerda Phase I despite a much larger number of detectors and hence radioactive hardware components.

nucl-ex↗

arXiv2016

Status Report of the GERDA Phase II Startup

The GERmanium Detector Array GERDA experiment, located at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN, searches for $0νββ$ of $^{76}$Ge. Germanium diodes enriched to $\sim 86~\%$ in the double beta emitter $^{76}$Ge ($^{enr}$Ge) are exposed being both source and detectors of $0νββ$ decay. Neutrinoless double beta decay is considered a powerful probe to address still open issues in the neutrino sector of the (beyond) Standard Model of particle Physics. Since 2013, just after the completion of the first part of its experimental program (Phase I), the GERDA setup has been upgraded to perform its next step in the $0νββ$ searches (Phase II). Phase II aims to reach a sensitivity to the $0νββ$ decay half-life larger than $10^{26}~$yr in about 3 years of physics data taking. This exposing a detector mass of about $35~$kg of $^{enr}$Ge and with a background index of about $10^{-3}~$cts/(keV$\cdot$kg$\cdot$yr). One of the main new implementations is the liquid argon scintillation light read-out, to veto those events that only partially deposit their energy both in Ge and in the surrounding LAr. In this paper the GERDA Phase II expected goals, the upgrade work and few selected features from the 2015 commissioning and 2016 calibration runs will be presented. The main Phase I achievements will be also reviewed.

physics.ins-det↗