Scientific Open-access Literature Archive and Repository
Not a member yet
16397 research outputs found
Sort by
ReD dual-phase, liquid argon time projection chamber
No full textWithin the DarkSide project, the ReD (Recoil Directionality) experiment was set up to study and characterize the performance of a double-phase argon Time Projection Chamber (TPC), testing for directional sensitivity and response to
very low energy nuclear recoils. The TPC of ReD was characterized at INFN Napoli with γ and neutron sources, to evaluate its performances in various conditions. This
article presents the main results obtained during the characterisation campaign
Cryogenic vacuum issues affecting mirrors of future gravitational wave observatories
No full textThe use of cryogenic mirrors in future gravitational wave detectors will reduce thermal noise, thus improving their sensitivity especially in the lowfrequency detection range. However, when operating at cryogenic temperatures, an ice layer (“frost”) will form on the mirrors’ surface, perturbing or even preventing detection. Frost formation can be reduced but not avoided. Then, to preserve the unquestionable improvements expected by cooling down the mirrors at cryogenic temperatures, a series of necessary solutions have to be adopted. In this paper, after
introducing a simple way to estimate the ice growth on the mirrors, potential mitigation methods to cure frost formation will be analysed and compared. Particular
emphasis will be given to the use of electrons to induce ice desorption. Such defrost method will clearly cause electrostatic charging, which has already been shown to
affect gravitational wave detection on running interferometers. Here we show that electrons not only can induce ice desorption, but can also mitigate charging issues
by properly tuning their kinetic energy
Automatic detection of volcanic ash clouds using MSG-SEVIRI satellite data and machine learning techniques
No full textVolcanic ash emissions can pose serious hazard to population living at the edge of an active volcano and can cause widespread disruption to aviation operations. Here an innovative machine learning (ML) approach, developed in Google Earth Engine (GEE), is proposed to detect volcanic ash clouds. It exploits the MSG-SEVIRI (Meteosat Second Generation - Spinning Enhanced Visible and Infrared Imager) images in the Thermal Infrared (TIR) range. This ML procedure was applied to the sequence of paroxysmal explosive events occurred at Mt. Etna between February and March 2021. It was demonstrated that machine learning algorithms combined with high temporal resolution satellite data offer a good solution to automatically detect, track and map a volcanic ash cloud
Machine learning analysis of a local seismic network in Mt. Amiata (Italy)
No full textSince March 2016 a small network of 11 seismic stations, deployed by Istituto Nazionale di Geofisica e Vulcanologia (INGV), has recorded about 1000 earthquakes in the southern part of Mt. Amiata. The continuous seismic waveforms are reprocessed with phase recognition pickers based on machine learning (ML) algorithms trained with global datasets of local earthquakes to get a more comprehensive earthquake catalog. This new catalog is compared with the already available events picked and located manually to assess the performance of ML-based analysis. The manually detected earthquakes are then used to assemble a dataset suitable for ML analysis. In a later stage, we investigate how the automatic detection performance could be further enhanced with specific training of the ML pickers with data coming
from the INGV network (INSTANCE dataset) and from the local network itself
Characterization of a SiC detector for dosimetric application
No full textNew detectors development for dose monitoring in radiotherapy application is a very active field. Silicon carbide (SiC) devices are considered promising candidates, mainly due to their radiation hardness, wide bandgap, high electron saturation velocity, linearity with energy and independent response from dose rate. These properties make them suitable also for the detection of very high intensity
particle beams, for which conventional semiconductor detectors cannot adequately perform. In this work a first I-V characterization of a 10 μm thick SiC detector embedded in epoxy resin before and after its immersion in water is discussed. The detecor’s depletion voltage, capacitance, stability, linearity and reproducibility were evaluated as well. The results demonstrate that the potting technique and
immersion in water do not affect the functionality of the detector, making it a good candidate for dosimetric applications
The Cryogenic TArgets for DIrect Reactions (CTADIR) project
No full textThe study of nuclei far from stability increasingly relies on measurements performed at exotic beam facilities. Direct reactions with exotic beams are a powerful tool to probe the single-particle degree of freedom of nuclear systems far from stability. However, the low intensity of exotic beams requires thick light targets to achieve the necessary luminosity. We present the project CTADIR, which aims at building a cryogenic 3,4He target to be employed at the SPES exotic beam facility at Laboratori Nazionali di Legnaro
Predicting β-decay rates of radioisotopes embedded in anisotropic ECR plasmas
No full textStudying in-plasma decay rates as a function of ionic charge state distribution (CSD) is the fundamental objective of the PANDORA project. To this effect, we present here two theoretical models to calculate β-decay lifetimes of radionuclide ions embedded in an energetic electron cyclotron resonance (ECR) plasma, starting from anisotropic electron distributions. The first model —designed as separate modules to implement various atomic processes like electron-ion reactions, ion-ion charge exchange collisions and ion loss dynamics sequentially— serves as a predecessor to a more robust second model aimed at coupling ion population kinetics with complex transport phenomena in an ECR plasma. The outputs from the models —in the form of space-resolved CSD and level populations— can be fed to an appropriate code based on known theories connecting atomic level configurations to decay lifetime to calculate the position-dependent β-decay rate
The DUNE photon detection system
No full textThe DUNE Photon Detection System (PDS) is based on a novel
cryogenic light-detector called X-ARAPUCA. It downshifts the 127 nm Liquid Argon (LAr) scintillation light and employs a dichroic filter to trap photons inside a reflective box, which is instrumented with Silicon PhotoMultipliers (SiPM) arrays. In this paper, we present a brief overview of the design and performance of the X-ARAPUCA, in view of the Run II of ProtoDUNE-SP at CERN. Furthermore, two X-ARAPUCAs were employed in Run I to validate the effectiveness of xenon
as a LAr dopant against the quenching effect of nitrogen impurities. Preliminary results of this special run are also presented
Scenario modelling for the Divertor Tokamak Test facility
No full textThe scenario integrated modelling is a top priority work during the design of a new tokamak, as the Divertor Tokamak Test facility (DTT) under construction at the ENEA Research Center in Frascati. The first simulations of the main baseline scenarios contributed to the optimization of the DTT project, particularly with regard to the machine size and heating systems, besides serving as reference for diagnostics design. In this paper we report the first simulations of the full power baseline scenario in the final configuration of the machine and heating mix
Advantages of two-photon processes in quantum batteries
No full textWe consider a Dicke quantum battery made of N two-level systems embedded into a microwave cavity. We assume a matter-cavity radiation characterized by both single- and two-photon processes. In the N = 1 case we analyze how the performances of the device are affected by the initial state of the cavity. By increasing N, we demonstrate that the two-photon interaction allows an improvement of the averaged charging power with respect to the single-photon one